Chapter 5 Biogeography: Distribution of Plants and Animals A · PDF fileThe diversity of California’s plants and ani-mals is in large part a ... These include climate ... factors

Chapter 5Biogeography:

Distribution of Plants and Animals

The state’s astounding variety of biotic communities with their diverse collec-tions of plants and animals is examined in this chapter. The living laboratory wecall California is so enormous and biologically diverse that the study of it poses

some problems: Where do we start? How do we organize our study? How do we clas-sify the various living environments? Of course, these same problems confrontbotanists, zoologists, and biogeographers around the world. However, scientists

studying California’s plants and animals haveengaged in exceptionally fascinating and con-troversial debates involving these problemsand other related issues. Their debates oftenrevolve around the diversity, connections, andchange that are major themes throughout thisbook.

The diversity of California’s plants and ani-mals is in large part a result of the state’s widerange of latitude and elevation and its positionon North America’s subtropical and mid-lati-tude west coast.�

A Breathtaking Assemblage of Living Organisms

126

127

� BIOMES

Past biogeographers have sometimes tried to organizeterrestrial California into general biomes. (Biomes aredefined as the largest regional ecologic units, or subdivi-sions, of plants and animals.) The logic of this system isthat biomes are the largest recognizable terrestrialecosystems, and an ecosystem represents a group of in-teracting organisms and the physical environment inwhich they live. This simplified approach provides onlythe most general categories and associations of Califor-nia’s plants and animals. Consequently, the organiza-tional approach based on biomes is no longer embraced

by scientists who search for a realistic understanding ofCalifornia’s living landscapes. It only serves as a startingpoint in our study.

Knowledge of specific habitats is also critical in thestudy of the distribution of plants and animals. (Habitatsinclude a combination of physical factors that representthe environmental conditions in which organisms live.These include climate, slope, soil, drainage, and manyother factors that are especially important to plants andanimals of California.)

In the simplistic biome scheme, the forest biome isoften the most productive and has the greatest bio-mass (total weight of organisms). In California, these

KEY ISSUES AND CONCEPTS

� The state’s unusual biological diversitymakes it a challenging place to study andclassify plants and animals. More general or-ganizational schemes that include the use ofbiomes and vegetation zones and belts reflectefforts to simplify these studies.

� California exhibits the tallest, largest, andsome of the oldest plants in the world. Com-munities vary from thick forests to sparsedeserts and from riparian woodlands tosandy dunes. Remarkable diversity is therule.

� The organization of California’s plantsinto communities is most effective, comparedto other organizational schemes. These com-munities, with their species, are in variousstages of succession as they evolve withinspecific environments. In this chapter, a gen-eral survey of each plant community’s habitatand structure is followed by more detaileddiscussions of specific plants and animalscommon to each community.

� Water availability, temperature, solar radi-ation, humidity, elevation, soil, slope expo-sure, fire, human impacts, and a host of otherfactors determine the nature of each plant

community. Generally, the greatest biomassand diversity will be found in California land-scapes where water is available for thelongest period and year-round temperaturesare mild.

� Most of the state’s plants and animals haveadapted to long summer drought, occasionalfire, and other environmental conditions andevents common to California.

� A transition of plant communities is evidentin cismontane California from the coast to in-land valleys and from sea level to higher eleva-tions. The most general changes result fromclimatic conditions reviewed in Chapter 4.

� In dry transmontane California, plant com-munities are generally more lush at higher el-evations and near oases, where cooler,moister conditions prevail. Such plants andanimals yield to the more widespread,hardier desert scrub species better adaptedto adverse conditions in lower deserts distantfrom water sources.

� Ecologic islands, riparian, dune, andother isolated plant communities resultwhen local habitats differ from their gen-eral surroundings.

128 Chapter Five Biogeography: Distribution of Plants and Animals

biomes appear in more favorable habitats, where thereis more water and where temperatures are not tooextreme. These forests are abundant in higher eleva-tions of cismontane California and especially acrossthe western slopes of central and northern California’smajor mountain ranges. More specific forest biomes inCalifornia are the temperate coniferous forests (needle-leaved) and temperate deciduous forests (broad-leaved, often found mixed with coniferous forests inthe state).

The scrub biome could include environments fromthe coastal scrub to the chaparral and even into oakwoodlands. (Some biogeographers may not use thescrub biome. They might consider chaparral to be adwarf, sclerophyll forest, and they might consider the oakwoodland communities with their scattered trees to re-semble a savanna biome.) Regardless, we are now con-sidering plants and animals that suffer from considerablewater shortages or other adverse conditions comparedto their forest neighbors. These are typical of theMediterranean environments of lower and middle eleva-tions throughout much of cismontane California, espe-cially in southern and central California.

The grassland biome includes most of cismontaneCalifornia’s inland valleys, where even drier and hottersummers may eliminate most trees and shrubs.

The desert biome includes most of transmontaneCalifornia, where water shortages are most severe andtemperatures are extreme. Only the hardiest plants andanimals can survive in these environments with low bio-mass and less species diversity (number of differentspecies).

Finally, the tundra biome is found only in Califor-nia’s highest alpine environments. Here, cold tempera-tures and short growing seasons are important limitingfactors for plants and animals.

Some very general connections can be made whencomparing California’s biomes, vegetation structures,and habitats to other regions of the world (see Figure5-1). Many of these connections may have become ap-parent during our review of the state’s weather and cli-mate. One obvious example is how the state’s Mediter-ranean scrub is similar to that of Chile, the southwestcoast of South Africa, southwest Australia, and theMediterranean. All five locations exhibit the typicalMediterranean climates discussed in Chapter 4—eastof dominant subtropical highs, winter rain and summerdrought, and most experience coastal fog. Anotherconnection is the temperate marine coniferous forestcommon to northern California. Note how Mediter-ranean scrub often yields to similar forests in otherareas of the world where climates become cooler andwetter. More specific and numerous are the similaritiesto other geographic locations created by a wide rangeof altitudes and mountain barriers.

� VEGETATION ZONES AND BELTS

Just as there is controversy and oversimplification withthe biomes scheme, early attempts to organize Californiainto generalized life zones yielded categories that aretoo broad. In the 1890s, C. Hart Merriam recognized atransition of life zones in Arizona, from the hot and drylower deserts to the cooler and wetter forests at higherelevations. He and others after him made this simpleconnection: while traveling from lower to higher eleva-tions in the southwestern United States, we may en-counter six major biotic zones. These zones (Merriam’sLife Zones) resemble what we might observe if we weretraveling, instead, from drier and hotter northern Mexicoto northern Canada.

Although crude, this concept was sometimes ap-plied to California in general, and the Sierra Nevada inparticular, with surprisingly successful results. As we re-view these life zones here, we will use coinciding vege-tation zones to describe them. The different, but re-lated, concept of vegetation zonation by elevation is alittle more specific and was proposed by scientists longafter Merriam’s Life Zones (see Figures 5-2a and 5-2b).

The Lower Sonoran Zone is identified below about300 m (1,000 feet) on the slopes of the western SierraNevada and below about 1,200 m (4,000 feet) on theeastern rainshadow slopes where there is desert andgrassland vegetation similar to the hot, dry SonoranDesert. Below about 1,200 m (4,000 feet) on the westernslopes and 2,000 m (6,500 feet) on the eastern slopes isthe Upper Sonoran Zone. These higher semiarid envi-ronments are somewhat cooler and more moist. Chapar-ral, woodland, and even some pine forest begin to dom-inate on western slopes, while sagebrush rules on therainshadow slopes of the east side.

From about 1,100–1,800 m (3,500–6,000 feet) on thewestern slopes and 2,000–2,400 m (6,500–8,000 feet) oneastern slopes are the cooler and wetter mixed forests ofthe Transition Zone. A mix of yellow pine forests coverswestern slopes, while the resilient Jeffrey Pine grows oneastern slopes. From about 1,800–2,600 m (6,000–8,500feet) on western slopes and 2,400–3,000 m (8,000–10,000 feet) on eastern slopes is the Canadian Zone.Lush forests of lodgepole pine and red fir grow in thisstill cooler and wetter belt. From 2,600–3,200 m (8,500–10,500 feet) on the western slopes and at higher eleva-tions on eastern slopes is the Hudsonian Zone, home ofthe subalpine belt. Here are communities similar to thecoldest woodlands, or taiga, around Hudson Bay, whereonly short, widely spaced trees are found.

Above all of these, at the highest elevations, is theArctic-Alpine Zone with its alpine belt vegetation. Here,above the tree line, organisms are under greatest stressfrom the very cold temperatures and short growing sea-sons somewhat similar to arctic tundra.

Vegetation Zones and Belts 129

Note how these zones and belts are characteristi-cally tilted up into higher elevations on the easternrainshadow sides of mountain ranges. This is typical inCalifornia, where you must travel to higher elevationsin transmontane ranges to experience the moist condi-tions typical of lower elevations facing the ocean. A

good biogeographer will also notice that, though thesezones are easy to understand, they are still too generalfor California. There are just too many other factors thatdetermine which type of community will exist at anyone location—there are too many exceptions to theseschemes.

Needle-leaved and Mixed Broadleaved ForestsBroadleaved Forest/Woodland (Oak and Riparian)Coastal/Shrub Formations (Coastal Sage/Chaparral)Grassland Formations or AlpineDesert Scrub Formations, including Joshua Tree and Juniper

Vegetation of California

0

0

100 mi

100 km

Alpine

Figure 5-1 Distribution of Vegetation in California. Only themost general features of the state’s diverse vegetation can be shown onsuch a map.

� LIVING COMMUNITIES

Therefore, in this chapter, we use plant communities topaint a picture of California’s living landscapes. We havealready defined the more general biomes and ecosys-tems. In contrast, a community refers to the relationshipsamong animals and plants in an area. More specifically,it might be defined as a group of plants and animals that

interact with their environment within a space-timeboundary. This is a more precise method of studyinghabitats and life forms based on dominant species. It hasbeen widely accepted and used since Phillip Munz andDavid Keck developed it in 1959 (see Figure 5-2b).

Each community and its species has evolved overtime as a result of dispersal events, climate, slope, soils,fires, human interaction, and many other factors. Such


Pacific Ocean

Coastal Sage

Oak/Pine

CoastalRanges/Hills

InlandValleys

SierraNevada/MajorRanges

TypicalSouthTransect

TypicalNorthTransect

WESTEAST

Redwood/Mixed Evergreens

Montane Fir/Mixed Hardwoods

Montane Fir

Subalpine Fir

Juniper

Sagebrush

High Desert Scrub/Savanna

Chaparral/Oak

Grassland

Chaparral

Yellow Pine

Subalpine

Pinyon-Juniper

Creosote/Cactus Scrub

Saltbush/Alkali Scrub/Dunes

Figure 5-2a Vegetation Zones and Belts. Cross section showing simplified model ofvegetation zones and belts across the Sierra Nevada, from west to east.

12,000 feet

11,000 feet

10,000 feet

9,000 feet

8,000 feet

7,000 feet

6,000 feet

5,000 feet

4,000 feet(1,000 m)

(2,000 m)

(3,000 m)

3,000 feet

2,000 feet

1,000 feet

Sea LevelGrassland

Desert Scrub

Lower

Sonoran

Upper

Sonoran

Transition

Zone

Canadian Zone

(Lodgepole Pine/Red Fir)

Hudsonian Zone

(Subalpine)

Arctic-Alpine

Sagebrush

Jeffrey Pine

Sparse PineWoodlandChaparral

Yellow PineMix

12,000 feetLeeward SlopesWindward Slopes

WEST EAST

11,000 feet

10,000 feet(3,000 m)9,000 feet

8,000 feet

7,000 feet(2,000 m)6,000 feet

5,000 feet

4,000 feet(1,000 m)3,000 feet

2,000 feet

1,000 feet

Sea Level

Figure 5-2b Vegetation Transects. Still simplified, but more realistic, are these transectsfrom west to east across the entire state. Some plant communities common to northern Cali-fornia are listed in their proper locations above the transect; several southern communitiesare shown from west to east below the transect.

Communities of Cismontane California’s Lower Elevations 131

ecologic succession is a gradual, but continual, processafter each event or disturbance. A series of intermediateseral (non-climax) communities may eventually matureto a climax community. Such a climax community isconsidered to be in equilibrium so that it can maintain it-self until the next event or disturbance. One example ishow many of the state’s plant communities are stillevolving from the effects of the last Ice Age that endedmore than 10,000 years ago.

During that short 10,000 years, plant communitieshave adapted, and continue to adapt, to smaller climatechanges. On smaller scales, ecologic succession may fol-low a volcanic eruption, fire, flood, or landslide. Thismakes us question the concept of succession and howwe might define a climax community. Many modern sci-entists argue that the whole idea of a climax communityis idealistic at best and that we really should consider ourplant communities to be in dynamic equilibrium. Re-gardless, it would benefit any biogeographer studyingthis state to consider each plant community’s stage ofsuccession and the time since the last disturbance. Theseconsiderations help explain the complicated montage ofplant communities commonly encountered in the state’slandscapes.

We will begin at the coast and sweep inland, first atlower elevations, then up to the higher mountain terrainof cismontane California. We will then break to examinesome exceptions or islands in the general trends. Finally,we will look at some of the plants and animals of trans-montane California, on the rainshadow sides of themountains and in California’s deserts.

Specialized botanists and zoologists may cringe atthe thought of such a general survey of only the salient

features of California’s life forms, but it is the appropriateapproach in a book searching for more general connec-tions and relationships. Information in this chapter hasbeen drawn from many major surveys of California’splant communities. When there was conflict among theexperts, especially in the classification of specific plantcommunities, efforts were made to find common ground.

� COMMUNITIES OF CISMONTANECALIFORNIA’S LOWERELEVATIONS

Coastal Sand Dune and Beach CommunitiesBeach refers to the strip of coastline above mean tide in-land to the greatest extent of storm waves during highesttides. A foredune often marks the inland boundary ofthis strip that is occasionally inundated and disturbed bywave action. Beach plants and animals must adapt to atleast rare invasions of ocean waves. Coastal sanddunes may extend well inland of the beach and fore-dune to more stable ground. Though organisms here areprotected from or elevated above wave action, they mustadapt to shifting sands. Technically, the terms coastalstrand or littoral strip are synonymous with beach,though, unfortunately, they have been used to describeboth beach and dune zones.

Habitat and StructureMarine air moderates surface temperatures and bringsvital moisture to coastal dunes, unlike their counterparts

Figure 5-3 A combination of natives andintroduced species are found on thesewind-swept dunes around Morro Bay. Incontrast to human disturbances, manyplant species are responsible for stabilizingthe dunes. Still, they must survive shiftingsand, salt spray, and summer months with-out rain.

in California’s deserts. Winter storms may bring wavesthat wreak havoc on California’s beaches, but they alsobring frequent clouds, drizzle, and rain over the dunes.Summer fog and stratus keep temperatures down andrelative humidities up, resulting in lower evapotranspira-tion rates on coastal dunes. Due to the marine air, sum-mer air temperatures are rarely hot (especially on thenorth coast) and winter temperatures are rarely coldenough for frost (especially on the south coast). Just asocean water temperatures may change by only a few de-grees Celsius during the seasons, the difference inmonthly mean air temperatures is no more than 6�C–9�C(about 13�F) at any one location. At first glance, this mayseem like an ideal environment for plants.

Though air temperature extremes are not nearly assevere as on desert dunes, exposed sand surfaces evenalong the coast experience dramatic changes. Becausemany dune plants grow close to the sand surface, theymay endure wild fluctuations in temperatures. As highwinds along an exposed coastline keep the disturbedsand moving, they also bring sea salt spray.

Add to this the nutrient-poor substrate where waterdrains through so rapidly in one place only to pond innearby hollows, and we recognize conditions that pre-sent a series of challenges to living organisms. Becausethe amount of disturbance and sand and salt sprayvaries, and because soil conditions change dramatically,we expect to find a wide variety of organisms adapted tothe wide variety of conditions from the harsh sandybeach to more stable dunes farther inland.

Though about 23 percent of the California coast isbeach and dune, these plant communities account forless than 1 percent of California’s land surface. Many ofCalifornia’s dune communities have been destroyed oraltered, especially in the south. However, a few good ex-amples of natural dune environments exist, especially tothe north. The largest coastal dune fields are west ofSanta Maria and include southern portions of Pismo StateBeach. At a few locations, lines of dunes protect bayssuch as Morro Bay south of Morro Rock. Extensive dunecommunities (some undisturbed) stretch along parts ofthe coast from Cape Mendocino to the Oregon border.Human disturbances, such as trampling and off-road ve-hicles, have repeatedly destroyed anchoring vegetationand set formerly stabilized dunes in motion, especiallyalong the central and southern California coasts, oftenwith costly results.

Plants. Just above the high tide level, pioneer duneplants appear. These plants grow close to the groundand often have interconnected roots that form an ex-tensive network below the sand, including deep taproots. Such root systems also absorb available mois-ture and stabilize the sand. Most plants prefer themore protected leeward sides of coastal dunes. Manyare perennial succulents that conserve water; light

gray leaves that reflect light and reduce evapotranspi-ration rates are common. Introduced beach and dunegrasses are especially common in the north, while saltgrass and more desert-like species are more commonon California’s southern coastal dunes.

Other notable plants often have common nameswhich may summarize some of their characteristics.They include Beach Bur or Silver Beachweed (Am-brosia chamissonis), Yellow and Beach Sand Verbina(Abronia spp.), Beach Pea (Lathyrus littoralis), with itsclusters of tiny pink and white flowers, and the beauti-ful Dune or Beach Morning Glory (Calystegia or Con-volvulus soldanella), growing from deep roots fromOregon to the Mexican border. Beach or DuneEvening Primrose (Camissonia cheiranthifolia) mayalso be common. Like many of the grasses, other ag-gressive introduced species have stabilized dunes buthave also crowded out native plants. They include thetiny pink Sea Rocket (Cakile maritima), and Ice Plant(Carpobrotus or Mesembryanthemum chilensis) cov-ered with its tiny, shiny blisters. Hottentot Fig (Carpo-brotus or Mesembryanthemum edulis) is also com-mon, with its slender, juicy fingers pointing up out ofthe sand. These last few introduced plants are com-monly used as ground cover on California’s humanlandscapes.

Where coastal dunes stretch farther inland in Califor-nia, there is more protection from wind and salt spray.Dunes are more stable and support richer soils thatprovide friendlier environments to living organisms. Awider variety of plants and animals can thrive, givingrise to a mixture of dune plants and many species com-monly found in coastal scrub communities. These in-clude Dune or Coastal Buckwheat (Eriogonum parvi-folium), Tree Lupine (Lupinus arboreus) and CoastalSilver Lupine (Lupinus chamissonis), and showyherbaceous flowers such as California Poppy (Es-chscholzia californica). Even stands of Coyote Bush(Baccharis pilularis) are established on stable sand andare often joined orreplaced by California Sagebrush(Artemisia californica) in more southerly locations.

On many of the oldest and most stable dunes, succes-sion has produced impressive biomass. On the northcoast, the climax dune forest includes Shore Pine(Pinus contorta contorta) and Sitka Spruce (Piceasitchensis) trees. Moving toward the drier dunes to thesouth, undisturbed climax communities may includespecies common in oak woodlands, chaparral, anddesert-like conditions farther south. Exceptions to thisinclude hollows and traps where fresh water isponded at the surface or is immediately below the sur-face, allowing dune slack communities to evolve.Marsh and/or riparian plants such as sedges, rushes,



and willow thrive in these spots and phreatophytesgrow where water can be tapped just below the sandysurface.

Animals. Insects, lizards, mice, and other small ani-mal tracks on the dunes are indicators of the scarcityof food and the lack of larger mammals. Strikinglysimilar tracks may be found on the harsh dune envi-ronments of California’s inland deserts. Larger preda-tors on the coastal dunes are usually birds, includingred-tailed hawks, kestrels, and gulls. Meanwhile, vari-ous species of bees and butterflies are among the fly-ing pollinators of specific flowers in the dunes. One ofthe most famous is the El Segundo Blue Butterfly (Eu-philotes or Shijimiaeoides battoides allyni). It hasbeen isolated only on the dunes just above Dock-weiler Beach below the planes taking off from Los An-geles Airport! These endangered butterflies have en-joyed impressive local media attention as they feed offbeach buckwheat on the last dunes remaining in thisregion. They have become one of the many symbolsof what Los Angeles loses as it grows. They also sym-bolize the dozens of native dune plants and animalsthat have become endangered or extinct as humansmodify and destroy California’s delicate coastaldunes.

Coastal Scrub CommunitiesCoastal scrub plant communities are also known ascoastal sage scrub or soft chaparral. These names cor-rectly suggest the similarities with chaparral. However,the smaller plants with softer leaves and the more fre-quent sage and other aromatic species are conspicuousdifferences, especially in the south. These scrub commu-nities are common along California’s coast from Oregon

to the Mexican border, but they often creep farther in-land and to higher elevations toward the south, into theCoast Ranges, and even along the lower slopes of theTransverse and Peninsular Ranges. Coastal scrub com-munities are, however, restricted to elevations usuallybelow about 750 m (2,500 feet) throughout California.Most coastal scrub species are adapted to frequent fire.

Habitat and StructureCoastal locations guarantee some of the mildest diurnaland seasonal temperatures in the world. Moist air massespass over before being lifted by mountains, so winterprecipitation is less than it is on nearby higher terrain.Great variations in winter rains in the coastal scrub rangefrom more than 180 cm (70 inches) in the north to lessthan 25 cm (10 inches) to the south. This results in awide variety of species in areas from the wet north to thesemiarid conditions along the south coast. Summer fogand low stratus are common along California’s entirecoastal strip, delivering lower temperatures and higherhumidities in the coastal scrub than at inland locationsduring the dry summer months.

Coastal scrub will gradually blend and merge into avariety of other plant communities along broad ecotones(transitional zones between two different habitats). Thetype of community will depend on local and regionalconditions such as climate, slope exposure, and soil.Coastal scrub may invade coastal dune communitieswhich have been stable for many years. Without distur-bances, it may evolve into forest communities on thenorth coast. Coastal scrub species frequently blend intooak woodland, grassland, and chaparral communities,especially to the south. Semidesert species, includingsucculents, become common near the Mexican border.

Though only about 2.5 percent of California is coastalscrub, these plant communities are seen frequently by

Figure 5-4 The view looks over coastal sage scrubalong the central California coast. Buckwheat andpoison oak are a few of the many native plants grow-ing along with introduced species here. This land-scape shows signs of human impacts. Cool coastalfog and low clouds help these plants and animalssurvive summers without rain.

many Californians because large agricultural and popula-tion centers have been established among them. Unfortu-nately, this is also why these plant communities containmany of California’s rare and endangered plants and ani-mals. It is also why many Californians frequently and in-correctly assume that the weeds and other introducedspecies that thrive on the disturbed urban fringe are nat-ural elements of these communities.

Coastal scrub communities are generally recognizedby the drought-adapted, short, scrubby bushes andshrubs less than 2m (6 feet) in height. Dense growth iscommon, especially on north-facing slopes and thenorth coast. An explosion of soft green growth andspring wildflowers is common after wet winters, espe-cially during the first few years following wildfires. Bylate summer, the same communities have turned dry anddusty; shades of golden, gray, and brown dominate assome plants drop their leaves in these thorny, water-stressed environments.

Plants. On the wetter north coast, species includetaller bushes such as Coyote Bush or Chaparral Broom(Baccharis pilularis) and Tree Lupine (Lupinus ar-boreus). Lower shrubs include monkey flowers, espe-cially Sticky Monkey Flower (Mimulus or Diplacusaurantiacus), and wild berries, including CaliforniaBlackberry (Rubus vitifolius). Salal (Gaultheria shal-lon), with its berry-like fruits, and Poison Oak (Toxico-dendron or Rhus diversilobum) are also common.

Poison oak is common along much of California’scoast, growing from close to the ground to overheadvines where vegetation and wetter conditions willsupport it. Its shiny leaves grow out in groups of threeand often turn pink and red by late summer and fall.Even after dropping its leaves, stems contain thetoxic oils which can cause severe and painful rashes.Poison oak can often be identified by its smoothstems, as it lacks the hairs and thorns of wild berryplants.

Understory herbs such as Sword Fern (Polystichummunitum), Bracken Fern (Pteridium aquilinum), andvarious flowering plants are indicators of wetter soilsin north coastal scrub communities.

Moving south, the above species are often joined orreplaced by plants better adapted to prolongeddrought, especially on south-facing slopes. Whentheir shallow, extensive root systems can gatherwater, soft-stemmed shrubs and herbs grow rapidly.Most lose leaves or die back during the summerdrought. This is in contrast to the harder chaparralspecies which usually have deeper root systems andare sclerophyllous. (Sclerophylls are evergreen plantswith stiff, leathery leaves.)

California or Coastal Sagebrush (Artemisia cali-fornica) is a classic and often dominant coastal scrubshrub. Its tiny, soft, grayish-to-light-green leaves arestrongly aromatic and they have been used to makehealing washes and teas. It is not a true sage but it is inthe sunflower family. True sages (Salvia spp.) are alsocommon and sometimes dominate the coastal scrub.Black Sage (S. mellifera) has dark leaves and blackstems, Purple Sage (S. leucophylla) has lighter leavesand purple flowers, and White Sage (S. apiana) haswhite leaves and is very common. All of these truesages have opposite leaves growing on square stemsand have pungent aromas. Some plants may bedraped with the parasite dodder, also known aswitches’ hair or broom for its rusty orange tangle ofstringy stems.

The many species of buckwheat (Eriogonum spp.) alsohave tiny leaves. Their dense clusters of tiny flowersform terminal heads upon small shrubs. Pink flowersof California Buckwheat (E. fasciculatum) turn a con-spicuous rusty brown when they dry. Other smallplants common in California coastal scrub includeDeer Weed (Lotus scoparius), a small shrub with onlya few small leaves on slender stems and numeroustiny, classic pea-shaped flowers. Various monkeyflowers (Mimulus spp.) are also common.

During long periods without fire, many woody coastalscrub species may grow a few meters (several feet)tall. They may grow into the chaparral communities.Like chaparral plants, most of these crown-sprout afterfires. Laurel Sumac (Malosma or Rhus laurina) hasclassic taco-shaped leaves and is not frost tolerant.Lemonade Berry (Rhus integrifolia) grows along theimmediate coast. Its red, acidic berries may be used tomake a bitter drink. Its relative, Sugar Bush or SugarSumac (Rhus ovata) is usually found farther inlandwhere summers are hotter. These last three speciesoften grow in southern coastal scrub on north-facingslopes.

Into the Driest Coastal Scrub. Even farther south,especially on more exposed, south-facing slopes,these coastal scrub communities become southernsemidesert coastal scrub or maritime desert scrub.Plants are usually smaller and more widely scattered.Species tolerant of even drier conditions includeYucca or Our Lord’s Candle (Yucca whipplei). Withits long, narrow, sword-like leaves, it has been de-scribed as looking like a giant pincushion. CaliforniaIndians weaved fibers from the leaves to make basketsand other necessities and ground the roots to makesoap. Older Yuccas bloom and die after sending outroots that produce younger plants nearby. For morethan 1m (3 feet), clusters of its white flowers bloom



along the top of a stalk that is even taller. These stalksbecome conspicuous to humans during late springand early summer; they are even more attractive to theYucca Moths (Tegeticula spp.), whose larvae feed offthe Yucca fruit that develops from the moth-pollinatedflowers. Indians roasted flower stalks and ground theseeds for flour.

Prickly Pear Cactus (Opuntia littoralis and other Op-untia spp.) are common on the driest slopes. Withthorns removed, their large, fleshy pads and their fruits(called “tunas”) have been eaten since the Indians andSpanish discovered them. Bright yellow sunflowers ofCalifornia Encelia or Bush Sunflower (Encilia califor-nica) have dark brown centers and grow at the end oflong stalks. Bush Sunflower is related to Brittlebush(Encelia farinosa), which grows only in the driest re-gions, especially inland, in southern California’slower deserts. Stonecrops or Live-forevers (Dudleyaspp.) are very peculiar plants that survive on exposedcoastal rock faces and cliffs; many are now rare orendangered.

Animals. Numerous animals of the coastal sage scrubare similar or identical to desert species. Insects,arthropods, lizards, snakes, birds, and small mammalsaccount for much of the limited animal biomass, a re-flection of the low productivity in these communities.Ectothermic animals are often more successful herebecause they are more efficient energy users; manyconserve energy by becoming dormant during severedrought. Often, lizards feed on the abundant insectsand spiders, snakes (fewer in number) may feed off allthree, and various birds may eat any of them.

The Coast Horned Lizard (Phrynosoma coronatum)has a wide range across California and is closelyrelated to the desert species. This flat, rounded,prehistoric-looking insect eater prefers ants, but hasbeen seen eating bees. It can change its shade tomatch the color of its usually exposed and sandybackground. Populations are rapidly decreasing ashabitats are destroyed and humans harass and cap-ture them. Numerous other lizards are common inmany open areas across California, including thevery common Western Fence Lizard or Blue-BelliedLizard (Sceloporus occidentalis) and the Side-Blotched Lizard (Uta stansburiana). Both can beseen doing push-ups in the sun, probably to attractmates and to scare off potential predators.

With its alternate light and dark longitudinal stripes orcircular rings, the largest banded snake in California isthe Common Kingsnake (Lampropeltis getulus). It eatslizards, small mammals, and other snakes, includingrattlesnakes, which are also at home in coastal scrub

and many other California communities. The GopherSnake (Pituophis melanoleucus) imitates rattlesnakesin looks and behavior, but it preys on small rodents,lizards, eggs, and birds by crushing them. It is thelargest and perhaps most common snake in southernCalifornia.

Numerous small mammals live in the coastal scruband throughout California. They include manyspecies of small mice with large ears, which surviveby eating seeds, insects, and a variety of other foods.The nocturnal Deer Mouse (Peromyscus maniculatus)is a common example. The California Mouse (Per-omyscus californicus) is one of the largest mice in Cal-ifornia. Pocket mice and white-footed mice speciesare also common throughout these habitats. Differentspecies of woodrats or packrats (Neotoma spp.) arenotorious for gathering sticks and other available ordiscarded debris in piles to make their large nests.They may survive extreme drought by eating pricklypear cactus for water. Many species of kangaroo rats(Dipodomys spp.) are common from the coast to thedesert. With powerful hind legs, they can leap toavoid predators such as different species of rat-tlesnakes. The California Ground Squirrel (Sper-mophilus beecheyi) is a larger rodent that is com-monly seen during the day. All of these rodents arecommon throughout many California habitats, espe-cially into the chaparral; many become food forsnakes, birds, or larger mammals.

Without abundant food, the larger mammals are fewand usually must roam through or make visits to thecoastal scrub for food while birds have the advantageof being able to fly to food and water sources. Mam-mals become more common and include largerspecies in areas that are ecotones to other plant com-munities, especially near wetter habitats farther north.These may include ringtails, bobcats, mountain lions,gray fox, coyote, mule deer, and even black bears.

GrasslandsOriginally, about 13 percent of California was coveredby grasslands. These are mostly in California’s inland val-leys, especially those tucked behind coastal hills ormountains. They are not deserts; they are usually a partof cismontane California. These great valleys include theSacramento, San Joaquin, and Salinas and other inlandvalleys surrounding the Bay Area as well as inland re-gions of the southern California coastal plains.

Habitat and StructureMost grasslands receive less winter precipitation than ad-jacent higher terrain where chaparral and woodland maydominate. Summers are long, hot, and dry. Winter rains

drain quickly through the thick, porous soils of these in-land valleys, often leaving roots dry; poorly adaptedplants wither by early summer. There are also coastalgrasslands scattered from Oregon past the Mexican bor-der. Though precipitation may be greater and tempera-tures milder, coastal grasslands often grow in fine-grained or nutrient-poor soils that may becomewaterlogged in winter but can dry into formidable hard-pan surfaces in summer. Most trees and even shrubs can-not survive in these adverse environments due to a lackof water or nutrients or both.

These communities are often divided into valleygrasslands and the cooler, wetter northern coastal grass-lands or coastal prairie. Inland valley grasses creep intohigher elevation chaparral and woodland communitieswhere soils become poor or into drier, south-facingslopes. Along the coast, they are also more common onsouth-facing slopes; they may grow into woodlandswhere more moisture is available to plants for a longerperiod or they may yield to coastal scrub or chaparralwhere soils become more porous.

This is a community restricted to elevations belowabout 1,200 m (4,000 feet). Only about 1 percent of Cali-fornia’s native grasslands, with their perennial bunch-grasses and other species adapted to these adverse con-ditions, have survived. Invasions of more aggressive,nonnative weeds and European grasses, overgrazing,farming, and urbanization have eliminated most of theoriginal grasslands. Of the few remaining patches of na-tive California grasslands, the Carrizo Plain (just west ofthe southern San Joaquin Valley) is probably the largest;it was saved by the California Nature Conservancy.

California’s Kansas? In Elna Bakker’s classic book,An Island Called California, she referred to the grass-land plant community as “California’s Kansas,” illustrat-ing striking similarities to the U.S. Great Plains grass-

lands. For example, the pronghorn antelope and tuleelk, like the plains buffalo, played the role of large graz-ers in California’s Central Valley.

Bakker also pointed out the many differences be-tween the two environments. California’s grasslands arefrequently interrupted by other plant communities. Eventhe Great Central Valley has wide fingers of riparianwoodlands, scattered vernal pools, and extensive wet-lands meandering down from the Sierra Nevada andspreading across the valley. Though temperatures dropto freezing each winter, California’s inland valleys neverexperience the prolonged hard freezes and bitter cold ofthe Great Plains. Finally, while California’s grasslands arestressed and challenged by prolonged summer drought,


Human Imprints

ural desert. It is estimated that about 700,000 small cattleand sheep grazed California landscapes during the peak ofthe Spanish Period. By 1862, 3 million cattle and 9 millionsheep grazed in California, many near gold rush popula-tions. Because European grasses were adapted to centuriesof this intensive grazing, they thrived in California’s grass-lands as native grasses disappeared. Unfortunately, contin-ued overgrazing and overfarming have destroyed about onethird of these once productive lands. Expanding networksof deep rills and gullies and windblown dust and sand arecommon evidence of the accelerated soil erosion in Califor-nia’s marginal lands; pursuit of short-term profits at the ex-pense of long-term productivity is often the cause.

The range of grasslands across California probably expandedslightly due to early human activities, but productivity has de-creased more recently. Native Americans were the first to mod-ify these marginal environments by burning them, knowing thatthe fresh regrowth would support more game animals. Ranch-ers have cleared borderline coastal scrub, chaparral, and oakwoodland to introduce Mediterranean grasses and expand theirgrazing land for domestic livestock. Eventually, native grass-lands became the most modified, destroyed, and misunder-stood general plant community in California. Early pictures ofland surrounding Spanish missions and Mexican ranchos some-times illustrated the already barren, trampled, overgrazed land.

This is one reason why these parts of California thatwere once native grasslands have often been mislabeled nat-

Figure 5-5 Grasses mix with oak trees in this transition be-tween communities that is so common throughout California.The grasses have dried in summer’s heat, but some species of oak trees will survive with their sclerophyllous leaves.Grasses will rule at lower elevations, while oak trees shouldbe more numerous at elevations above this scene.


the Great Plains enjoy occasional spring and summerdownpours.

Consequently, California’s perennial bunchgrassesare ready to explode into growth during the first warmearly spring days, while plains grasses will emergefrom buried roots later in the spring. By late spring,California’s grasslands are already stressed in dryingsoils, while plains grasses thrive well into summer. Cal-ifornia’s native bunchgrasses are better adapted to thelong summer drought, but the introduced Europeanspecies quickly turn to brittle brown and gold in earlysummer heat.

Plants. Hundreds of plant species once flourishedand are now scattered in California’s native grass-lands, some of which are often seen in bordering plantcommunities. They include perennial bunchgrasses,annual grasses, and annual wildflowers. The mostcommon native perennial grasses include PurpleNeedlegrass (Stipa pulchra) and the bluegrasses (Poaspp.). In spring, these bunchgrasses grow quickly fromtufts to produce flowers. The many introduced grasseswhich now dominate and are most frequently seenacross California’s grasslands include wild oats(Avena spp.), fescues (Vulpia or Festuca spp.), brome(Bromus spp.), and many others. Growing among thegrasses, native wildflowers may produce the most re-markable displays of spring. They include CaliforniaPoppy (Eschscholzia californica), various lupines(Lupinus spp.), Owls Clover (Orthocarpus spp.), andmany sunflowers, such as Goldfields (Lasthenia cali-fornica or L. chrysostoma). Growing from bulbs, mari-posa lilies (Calochortus spp.), amaryllis such as BlueDicks (Dichelostemma pulchella or Brodiaea pul-chella), and iris such as Blue-Eyed Grass (Sisy-rinchium bellum) add to the brilliant spring displays.

Also common in California grasslands are the manyspecies of mustard; most of them are introducedweeds. Black Mustard (Brassica nigra), with its smallyellow flowers atop slender stems sometimes growshigher than 2m (6 feet); it is responsible for turningmany California hillsides into fields of yellow inspring. Franciscan padres first spread these very suc-cessful invaders with black seeds. Even the edibleWild Radish (Raphanus sativus) is a very common in-troduced member of the mustard family. Horehound(Marrubium vulgare) is a mint introduced as a coldremedy. It is now common in disturbed sites andfields, where its fruits turn into annoying burrs whichare distributed after they have attached to animal furor to our clothing. Many different native and intro-duced thistles are also common. Some introducedthistles are so aggressive that they are quickly spread-ing from their disturbed sites and overtaking nativehabitats.

In the northern coastal grasslands or coastal prairie,many different species of perennial bunchgrasses arecommonly joined by sedges, rushes, perennial forbs,and species also found in valley grasslands. Becausesoils remain wetter for longer in these northern grass-lands, foliage is also greener throughout the year.

Animals. We have already noted the impact of do-mestic livestock on California’s grasslands. A diverseassemblage of native fauna also lived in or wanderedthrough the many adverse conditions common tothese habitats. Most of these animals thrived with theabundant moisture and fresh growth of spring, butstruggled to survive in dried habitats of late summer.Classic lessons in the study of California food pyra-mids are often taken from these grasslands.

There are abundant small herbivores, or primary con-sumers, especially insects. Grasshoppers, ants, andcrickets compete with small mammals and birds foredible new growth in spring and seeds later in theyear. Meadow mice, pocket mice, kangaroo rats, go-phers, and California ground squirrels share the grass-lands with seed-eating birds such as goldfinches andsparrows. With fewer predators, the gopher popula-tion has exploded to more than thirty per acre in somefields. Jackrabbits, with their giant ears, may be seendarting between covers to eat native and introducedplants.

Grasshopper mice, deer mice, and lizards prey onmany insects as do carnivorous birds, such as king-birds, nighthawks, and meadowlarks. Other sec-ondary consumers, such as snakes, coyotes, foxes andbadgers, and predatory birds, such as burrowing owlsand American kestrels, may eat small mammals. Someof these animals, such as the coyote, are omnivores;they consume a wide variety of plants and animals toincrease chances for survival in adverse conditions.

Red-tailed hawks are frequently seen soaring abovegrassy areas in search of rodents or reptiles for dinner.With their light undersides and red-tinted tails, theyseem to glide effortlessly in daily thermals until theyswoop down on their stunned prey. Numerous bur-rows, which punctuate these grasslands, indicate ef-forts by smaller mammals to escape both extremes inweather and their predators. As we work our waythrough the pyramid from the producers toward thetertiary consumers, the size of the animals generallyincreases, but the total biomass greatly decreases.

Tule elk and pronghorn antelope were the two largegrazing animals of the Central Valley grasslands. TheTule elk, the smallest elk in North America, is indige-nous to California and was endangered for years. After

near extinction, numbers increased into the hundredswithin natural reserves in the San Joaquin and OwensValleys. Now overgrazing by increased populations isbecoming a problem. A herd size of 2,000 is often thenumber cited by those who want to maintain ahealthy population in California’s reserves. This TuleElk (Cervus elaphus nannodes) is smaller than theRoosevelt Elk (Cervus elaphus roosevelti) of north-western California.

Pronghorn antelope were also nearly driven out ofCalifornia, except for the northeastern part of the state,but there are populations of this species in otherstates. The rare or endangered status of so many Cali-fornia grassland animals is an obvious result of rapidencroachment of human activities and populationsand the destruction of these plant communities.

Oak WoodlandsOften referred to as foothill woodlands and sometimesgrouped under the more broad, global biome, “sa-vanna,” oak woodland plant communities may containseveral different types of oak trees and associatedspecies. They are spread and scattered around cismon-tane California from Oregon to Mexico usually in areaswetter than grasslands, but drier than forests. Oak wood-lands surround the Central Valley.

Habitat and StructureVarious oak trees may appear with or replace grasslandsat higher elevations with more precipitation or wheresoils trap and hold water for longer periods, especiallyon north-facing slopes. Oak woodland may also replacecoastal scrub or chaparral where porous soils becomemore fine-grained and are capable of storing morewater, especially in cooler, shadier habitats. In contrast,the wetter California forests may be replaced by oakwoodlands at lower elevations or on drier, south-facingslopes, or where soils will not support forest growth.

At least sixteen species of oaks (Quercus spp.) andtheir woodlands grow from just above sea level through-out cismontane California. They may reach higher eleva-tions above 1,500 m (5,000 feet), especially in southernCalifornia. Climates are typically California Mediter-ranean with mild, wet winters followed by warm, drysummers. Depending on moisture and soil conditions,oak trees may be widely scattered with only grassesbelow. On wetter, especially north-facing sites, or nearcanyon bottoms, numerous large oak trees may evenjoin pines or riparian species to form a dense woodlandwith an understory of shrubs. Stately oaks are often apart of the scenic photographs and paintings depictinghistorical and rural California hillside landscapes. Cover-ing about 4 million hectares (10 million acres) or 10 per-cent of California, they also provided many Native Amer-

icans with the most common source of staple food—theacorn. Oak woodlands continue to provide unique shel-ter and food for hundreds of animal species.

The best illustration of how oak woodland commu-nities fit into California’s biogeographic landscapes isfound along the western Sierra Nevada. Traveling upfrom the drier valley grasslands, sparse oak trees andshrubs are first noticed until, at higher elevations, denseroak woodlands and shrubs may alternate with chaparraland forest species. Gradually, the oaks give way to pinesin the higher elevation ecotones between oak wood-lands and cooler, wetter forests.

On coastal slopes, wetter forests may give way to oakwoodland on drier south-facing slopes in northern Cali-fornia. In contrast, southern California’s south-facingslopes are often too dry for oaks; the coastal scrub, grass-lands, or chaparral only yield to oak woodlands in wetterlocations, such as north-facing slopes. Travelers throughthe Coast Ranges along highways such as 101 are certainto pass through a variety of oak woodlands that oftencontribute to California’s picturesque landscapes.

Plants. Oregon Oak, or Garry Oak (Quercus gar-ryana) is a deciduous white oak tree common tonorthern California and southern Oregon oak wood-lands. Growing inland from California’s coastalforests, it is the only California oak tree distributedwidely outside the state. More common to central Cal-ifornia, especially on the drier, hotter inland slopes isBlue Oak (Quercus douglasii), actually another decid-uous white oak tree. These large oaks have lobedleaves up to 7.5 cm (3 inches) long and feed numerousacorn-eating mammals. To the south, they are re-placed by the less common Engelmann Oak or MesaOak (Quercus engelmannii), a semi-evergreen whiteoak with long, smooth leaves, restricted to slopessouth of the Transverse Ranges.

Commonly found on wetter and north-facing coastalslopes from the Coast Ranges south is Coast Live Oak(Quercus agrifolia). As its name implies, it is evergreenand commonly grows in clusters on coastal slopes ad-jacent to coastal scrub, chaparral, and grassland com-munities. Its small, hard, spiny leaves suggest adapta-tions to drier climates more typical of chaparralspecies, such as its very similar but much smaller rela-tive, California Scrub Oak (Quercus dumosa orberberidifolia). An even closer relative that grows onmany central California stabilized sand dunes is theDwarfed Coast Live Oak or Pygmy Oak (Quercus agri-folia var. frutescens). This dwarf variety may survivethe strong, salty winds, poor soils, and other adverseconditions which rule out larger oaks.

Golden-Cup Oak or Canyon-Live Oak (Quercuschrysolepis), with its giant yellow cups holding each



acorn, and Black Oak (Quercus kelloggii) are com-mon on moist and higher elevation sites and are someof the most widely distributed oaks from northern tosouthern California. Large-lobed leaves of deciduousblack oaks are often responsible for producing the fallcolors on southern California’s higher mountainslopes.

The Valley Oak (Quercus lobata) is California’s largestoak. Growing on low hills and in valleys from north-ern California to the Santa Monica Mountains, it formsopen savannas in drier areas and forests near riparianstrips. Individuals more than 30 m (100 feet) tall withnearly equal diameter crowns and trunk diameters upto 3m (9 feet) have been measured. They also havevery large, lobed leaves and long acorns. Most of theoriginal stands have been destroyed for firewood orreplaced with grazing and agriculture. Interior LiveOak (Quercus wislizenii) grows mostly in higher ele-vations of inland California, from the Cascade andSierra Nevada foothills to the Peninsular Ranges,where it becomes shrubby in a drier habitat.

In California, deciduous oaks are often identified bytheir larger, softer leaves, while evergreen oaks usu-ally have smaller, harder leaves.

Many of the deciduous oaks are found in northernCalifornia or at higher elevations; they may drop theirleaves to escape past or current winter cold. Evergreenoaks live in milder climates or have adapted to thecold. They often have extensive and deep root systemsthat can access water most of the year. Oaks often

grow in clusters because they resprout after fires orwhere squirrels buried acorns and did not retrievethem. Human activity, such as trampling or overwa-tering the root systems, and especially habitat destruc-tion due to agriculture and urbanization has alreadywiped out many of California’s oak woodlands. Nu-merous California communities have passed laws todiscourage the continued destruction of oak trees.

A Wealth of Other Plants Mix with the Oaks. Sev-eral other interesting plant species are commonly as-sociated with oak woodlands. California Buckeye(Aesculus californica) is California’s native in thehorse chestnut family and is common in and near oakwoodlands of central California. In spring, stalks to 13cm (5 inches) long are covered with white flowers.This drought-deciduous small tree loses its leaves bylate summer, leaving the large buckeyes, or horsechestnuts, dangling like pendulums in the autumnbreezes. Native Americans shelled, ground, cooked,and leached them for a high-carbohydrate staple dishsimilar to mashed potatoes; they are still an importantsource of food for animals.

Redbud (Cercis occidentalis) grows on hillsides sur-rounding the Sacramento Valley and along the west-ern Sierra Nevada. It is winter-deciduous, but is cov-ered with tiny pink flowers by early spring. As amember of the pea family, its brown pea pods are an-other important food source for animals.

The California Black Walnut (Juglaus californica) be-comes locally dominant in oak woodlands especially

Figure 5-6 This mix of chaparral and oakwoodland is typical of the Sierra Nevadaabove the drier foothills, but below thecooler, wetter mountain forests. Theseplants must adapt to long, hot, dry sum-mers that do not bring the fog and lowclouds of coastal locations.

on north slopes from Santa Barbara through OrangeCounty. Walnut woodlands are found in the Ojai Val-ley and in the Puente and San Jose Hills south andwest of Pomona. Some stands grow in the middle ofrecent urban sprawl, but many have been eradicated.This California walnut can be identified by its long,opposite leaflets. Its walnuts are not commercial qual-ity, but hungry squirrels do not seem to mind. In evenwetter sites, the oaks are joined by the more widelydistributed California Bay or Laurel (Umbellularia cal-ifornica), with its dark green, overwhelmingly pun-gent bay leaves. This species is usually found in wettercommunities, such as mixed evergreen forest. Wherecoastal summer fog is common, thin veils of LaceLichen (Ramalina menziesii) are draped over andhanging from oak trees like delicate yellow-green hairor beards, providing surfaces where more moisturemay condense.

Especially at higher elevations and on wetter sites,pines mix with the oaks. Gray (Digger) Pine (Pinussabiniana) is the first to appear in some of the driest lo-cations, where it grows in foothill woodlands sur-rounding the Central Valley and into the Coast Rangesin the same areas as blue oak. It is called gray pine be-cause of its long silver-to-light-green needles. Thisdry, scraggly pine may also be seen protruding abovechaparral plants as it divides into several largebranches.

Like most dry pines, it produces very large cones withseeds that were important for California Indians and arestill vital to the survival of some animals. Several otherpines and plants from grassland, coastal scrub, chapar-ral, and forest plant communities may mix with wood-lands when conditions are favorable. Common under-story plants such as poison oak are examined withinmore proper settings before and after this section.

Animals. Close inspection of oak trees reveals numer-ous smaller species and some of the larger species ofanimals making their homes and gathering food there.Excellent examples of a few of California’s parasiticand plant-eating insects include tiny aphids, whichsuck plant juices, and the white flies, oak moths, andtent caterpillars that consume green leaves. Larvaehatch from many species of butterflies to feed on oakleaves. Millions of various borers and beetles arepuncturing through the bark of oak, pine, and othertrees throughout California, sometimes killing theweaker trees. Bark beetles devastate pine stands dur-ing severe drought years when trees lack the sap to en-capsulate such invaders. Spotty patches of brown,dead pines grew to large clusters across the SierraNevada and other California mountain regions as barkbeetle infestations killed thousands of trees during the

early 1900s, marking the end of the longest drought inCalifornia history. As one of the worst droughts to hitsouthern California dragged through the first years ofthe twenty-first century, beetles devastated entiremountain forests.

Gall insects include the cynipid wasps. Females laytheir eggs on oak leaves or stems, the eggs hatch, andlarvae eat the plant, making irritating chemicalswhich cause the tree to grow a large gall at that point.New wasps eventually emerge from the protection ofthese crusty, hollowed, paper-light brown galls, leav-ing puncture holes upon exiting. Larger galls may looklike small, dried apples clinging to stems. Other para-sitic insects prey on oak woodland animals, such asthe bot flies on small mammals and the fleas, mosqui-tos, and biting flies on small and large animals.

A variety of birds eat the acorns and insects of oakwoodlands. The acorn woodpecker prefers to drill itsholes in softer dead trees to store the acorns it gathers.These powerful woodpeckers have distinctive redcaps. Natural inner cushions protect the head from im-pacts caused by constant drilling. They also eat insectsin the bark or in the air. Scrub jays hide their acorns inrich soil, where the forgotten morsels may sprout toseedlings. Numerous other animals, such as mule deerand squirrels, make acorns an important part of theirdiets. Some species, such as mice and rabbits, use oakunderstory for cover, while others, such as hawks andowls, use the top of oaks as observation posts. Fromtheir perches, such predators might spot one of themany amphibians, reptiles, or small mammals for din-ner. Large mammals such as the fox, coyote, bobcat,mountain lion, and black bear may live in or wanderthrough these woodlands, especially within ecotonesmerging into other plant communities.

ChaparralNearly 10 percent of California is covered with one of itsmost widespread and famous plant communities—chap-arral. Throughout cismontane California, chaparral isfound in drier spots with poor soils to the north. It be-comes far more common to the south, especially onporous soils inland from the coastal scrub up to higherelevations where it may finally yield to cooler, wettermontane forests. Therefore, the isolated chaparral wesee only in drier spots to the north becomes more wide-spread as we sweep south, especially into the southernCoast Ranges and Sierra Nevada. It dominates thefoothill and mountain slopes of cismontane southernCalifornia to higher elevations. Areas of chaparral evenspread into a few transmontane desert locations, whereit begins to resemble chaparral in Arizona and northernMexico.



Habitat and StructureThough many chaparral species are also found in “softchaparral” coastal scrub communities, true chaparraltends to be a taller, thicker, more evergreen community.It may receive more precipitation on higher slopes inwinter, but suffer through hotter, drier summers in areasmore distant from coastal fog and stratus. Typically, ex-tensive roots penetrate through very porous soils whichmay be well-drained, but nutrient poor.

Chaparral is the model Mediterranean, drought-adapted plant community. Most of the dense thickets ofshrubs are sclerophyllous, a term referring to the hardleaves which often are small with waxy or resinous coat-ings and fine hair. Leaves may also curl or be oriented todecrease direct sunlight, all adaptations to keep transpi-ration rates down during the long, hot summer droughts.Though productivity is relatively low, it averages sixtimes higher than deserts. Whether chaparral is domi-nated by small shrubs only several cms (a few inches)tall, or dwarf woodlands more than 4m (12 feet) high,these woody plants provide an almost impenetrableevergreen cover wherever they grow across Californiaslopes.

In even the most thorough study of chaparral, itwould be a challenge to examine the more than 800plants, including more than 200 woody plants that makeup California’s chaparral communities. Here, we focuson a few of the more common species. Many of Califor-nia’s chaparral communities may be distinguished andclassified by the dominant species or by habitat charac-teristics, such as location (island versus Sierran versussemidesert, etc.) or elevation, or soils. The assemblage ofplants in western Sierra Nevada chaparral is quite differ-ent from that found on California’s Channel Islands; theheavier rains and snows of winter and hot dry summersin the western Sierra Nevada are not known to the plantsof the islands. Another example of chaparral diversity isthe persistent high humidity, fog, and stratus of the is-lands, which is not known to the semidesert chaparralgrowing near piñon-juniper and Joshua tree woodlandsof transmontane California.

Chaparral species may also occur in locations whereforest or woodland is expected, but where outcrops ofpoor soils such as those weathered from serpentine havecreated adverse conditions. In southern California, chap-arral may replace oak woodland or grassland wherefine-grained soils change to the very coarse, porous, andwell-drained substrate favored by chaparral plants’ roots.Finally, slope exposure is a major factor that determinesthe dominant chaparral species. A quick glance at chap-arral on smaller, local hillsides within California’s majorlandscape trends reveals the shorter, sparse plant coveron drier south-facing slopes that face direct sun. Com-pare this to the taller, thicker, and lusher growth oncooler, wetter north-facing slopes facing away fromdirect sunlight. In marginal environments, slope aspect

may even produce completely different plant communi-ties on opposite slopes.

Many of the herbs and wildflowers of adjoiningcommunities, such as grassland and coastal scrub, arealso common in chaparral; this is especially true in openareas or after fires.

FireAll chaparral communities are adapted to fire. Manyspecies crown sprout (regrow from root crowns) afterfires. Some shed seeds which will only germinate after agood scorching is followed by moisture. A greater diver-sity of herbs and other species follows during the firstfew springs immediately following fires; the diversityand numbers of animals explodes along with the spec-tacular displays of wildflowers and fresh growth. Someof the herbs are considered “pyrophyte endemics,” be-cause they only germinate and grow after fires. As theyears after fire pass, species diversity usually decreasesas the woody chaparral thickets grow taller at the ex-pense of low ground cover.

After many years, only a few larger species maydominate. These mature stands often contain largeopenings below the canopy cover from the ground up toseveral cms (inches) high. The cavities provide passage-ways for small animals below the cover of chaparral,while enormous quantities of dead stems and leaves andother dried debris accumulate on and around the base ofthese plants. This fuel will contribute to the next wildfire,when temperatures may reach 700�C (1,200�F), and thefire succession cycle will continue.

Fire plays an important role in most California plantcommunities, especially in those adjacent to chaparral.Fire may ravage some California chaparral and coastalscrub slopes as frequently as every 15 years, on aver-age. The drought-adapted plants contain plenty of fueland relatively little moisture by summer’s end. Chamise(Adenostoma fasciculatum), a common chaparral dom-inant, is known to burst into flames as a fire approaches,when temperatures reach 427�C (800�F). It is no sur-prise that this is a classic drought-adapted species thatcrown sprouts after a fire and produces seeds whichmay lay dormant for years until they are scorched. Al-though fires are beneficial in the long term for plantcommunities, humans often consider them catastrophicdisasters.

Plants. Numerous species of manzanita (Arctostaphy-los spp.) grow throughout and sometimes dominateCalifornia chaparral from near sea level to highermountain slopes. Light green leaves grow from a back-ground of dark red, woody stems and smooth red bark,which make this an attractive species in the wild and agreat ornamental plant for domestic gardens. From its attractive pink flowers the famous “little apples”develop—berries that gave manzanitas their common


Californians and Fire

gions. In the long run, we will save lives and spend less moneyon fighting fires and on disaster aid. This will require moreknowledgeable and careful land-use planning in the future.Unfortunately, such long-term, common-sense solutions aredifficult to implement with increasing pressure from growingpopulations to expand farther into California’s wild areas,areas often seen to offer a part of the California Dream.

Today, developments continue to encroach upon areasdestined to burn in California. The wide ribbons of firebreaks—areas where vegetation is cleared along strips con-necting one ridge after another—are particularly obvious insouthern California. These may serve as future battle frontswhere fire crews are seen on TV, making their brave standagainst the next threatening fire. On days with higher humidi-ties and gentle breezes, fire crews may start control burns.These burns are designed to clear accumulated dead fuel andreturn a plant community to more natural conditions so thatthe next fire is not so hot.

After fires ravage hillsides near the urban fringe, localcrews may even seed the slopes with fast-germinating, non-native grasses. These introduced seeds are often washedaway with the first winter rains; they rarely provide a betterlong-term plant cover for protection from erosion than thenative species with which they compete. The practice con-tinues because it is seen as “doing something” to protect thecommunity. California’s annual dramas are played out eachyear with the suspense, tragedy, and irony experienced bycountless human populations around the world who havedared to venture into regions where the powerful forces ofnature are still in control. In California, the resulting land-scapes reveal fascinating interactions between nature andhumans.

We have built within numerous plant communities where fireis inevitable. Each fall, the national media displays yet anotherCalifornia housing tract or community burning to the ground.Many of these fires burn through several different plant com-munities and human settlements in one day and rank as someof the greatest fire disasters in our country’s history. Theyoften involve world-famous locations, such as Malibu, Laguna,Beverly Hills, Santa Barbara, Oakland, and Berkeley. Suchhuman disasters are compounded by the mudflows and severeerosion that follow when winter rains pound the hillsidesmade barren by the fires. In nature, these events may carryaway many of the nutrients deposited on the soil by fire. Inbuilt environments, the homes and structures not destroyedby the fire may be damaged or swept away in the next winter’sfloods. Californians have built in fire country, suppressed fires,and paid the price in the long term.

Though California Indians started their share of fires,there is evidence of frequent, smaller fires throughout Califor-nia long before humans played a role. These fires were startedby lightning and probably burned much smaller areas becausethey occurred on days with rain and higher humidities. It isalso likely that smoldering logs and embers left by smaller fireserupted weeks or months later during dry, windy conditions,occasionally causing more spectacular and widespread wild-fires. During much of the 1900s, humans suppressed naturalfires throughout California, allowing dangerous accumula-tions of dried fuel near their communities. As a result, modernwildfires—sometimes started by accident or by arson—oftenerupt when hot, dry winds can fan flames feeding on exces-sive accumulations of fuel.

It is impossible to stop and difficult to direct a firestormblazing through overly mature chaparral or other plant com-munities when temperatures are near 38�C (100�F), relativehumidities are below 10 percent, and winds are gusting over80 km per hour (50 miles per hour). Yet, these are frequentlythe conditions firefighters encounter during autumn’s SantaAna winds in southern California. Each year, these infernos re-turn as regularly as the seasons. Because of past fire suppres-sion, today’s wildfires may burn so much accumulated fueland reach such high temperatures, they kill native plants andanimals that may have otherwise survived to quickly repopu-late an area.

Consequently, from civilization’s standpoint, Californiahas one of the most dangerous and destructive fire seasons inthe world and Californians constantly argue about what to doabout it. Even in some of our most remote forests and parks,we have aggressively attacked wildfires to “save” valuable tim-ber, watershed, or recreational lands. We have only recentlylearned that by allowing some wildfires to burn or by practic-ing control burning, we will actually restore plant communi-ties to their natural states and decrease the threat of more dis-astrous fires in the long run.

These are difficult policies to implement in a state withmore than 37 million people, especially when lives and valu-able property and resources are at stake. The most obviouscorrection we can make is to stop building in fire-prone re-

Figure 5-7 This fire burns through the chaparral along I-5north of Los Angeles where the Tehachapis meet the Trans-verse Ranges. Fire crews would eventually extinguish an-other fire that was likely started by a careless passerby. Mostof these plant communities have adapted to such scorching.


name. Manzanita is also used in about fifty Californiaplace names. It frequently creeps into other plantcommunities, such as yellow pine forest, where it maydominate the understory. Except for its different flow-ers and lack of red bark, the Silk-tassel Bush (Garryaspp.) could be mistaken for manzanita.

Several species of ceanothus (Ceanothus spp.), withtheir small, green leaves, are often called Californialilac. Different species grow tiny clusters of variouscolored flowers from white to blue that bloom in thechaparral from lower elevations in late winter to higherelevations into summer. Rubbing the flowers withwater may produce a mild, sudsy soap. Nearly purestands of ceanothus may grow higher than a few me-ters (several feet) to maturity within several years afterfire. They may die of old age within 10 years to clearthe way for other species. With nitrogen-fixing roots,they help increase soil fertility for plants to follow.They are also known to throw or pop their seeds awaywhen mature. Though they may not crack unless theyland on very hard surfaces, the seeds will crack in laterfires.

Mountain Mahogany (Cercocarpus betuloides) is an-other typical chaparral species that is a nitrogen fixer.Smaller plants from the pea family such as Deerweed(Lotus scoparius) and lupines (Lupinus spp.) also typi-cally move in after fires as nitrogen fixers and restoresoil fertility.

Chamise (Adenostoma fasciculatum) is another chap-arral species found in almost pure stands. However, itoften grows as a lower shrub in drier sites with evenmore classic drought and fire adaptations (some werereviewed in the previous “Fire” section). With its tiny,hard leaves (which superficially resemble buckwheat)and extensive root systems, it may be the most com-mon chaparral species in California.

Red Shanks (Adenostoma sparsifolium) is often calledribbon bush or ribbonwood due to the dry strips or rib-bons of rusty bark that peel, hang, and curl off theplant. It also has tiny leaves, but it grows much tallerthan chamise to form dwarf woodlands, usually invery mature stands between elevations of about 600m (2,000 feet) and 1,800 m (5,900 feet), which havenot been burned for many years.

Especially common on southwestern Sierra Nevadachaparral slopes is Flannel Bush (Fremontodendron orFremontia californicum), with its long, conspicuousstalks of yellow spring flowers. It is commonly associ-ated with montane chaparral, but also grows on thedry side of the Transverse Ranges. Its other name, Fre-montia, was taken from the historical figure, John C.

Frémont, and was adopted for the publication of theCalifornia Native Plant Society.

Various desert and scrub varieties of oak grow in thechaparral, including California Scrub Oak (Quercusdumosa). Its dwarfed size and its small, thick, hard,and often spiny leaves are among this plant’s typicalchaparral characteristics. It is important to many ani-mals of the chaparral, especially as a source of acorns.

Other interesting and important chaparral plantswere overlooked here for the sake of space. It is saidthat Toyon (Heteromeles arbutifolia), has the holly-like leaves that gave Hollywood its name. It is alsoknown as Christmas berry, for its ripe red clusters ofberries which appear in front of a green leaf back-ground by late December. Toyon grows in manychaparral communities, including the hills aboveHollywood. Man Roots (Marah spp.), or wild cucum-bers, grow each year as vine-like plants creepingthrough chaparral and adjacent communities. Theyemerge from a giant tuber which may reach the sizeof a person. Its baseball-sized fruits grow giant thornswhich make them resemble weapons from a sciencefiction movie. Once cut open in spring, they mayalso resemble cucumbers with their internal seeds.Various currants and gooseberries (Ribes spp.), otherberry plants (Rhamnus spp.), and such species asSugarbush (Rhus ovata) are also common in thechaparral.

Animals. Though productivity may nearly doubleafter a fire, production in the chaparral still averagesabout 600 g per sqm per year (5,300 pounds per acreper year), compared to only 335 g/sqm/year (3,000pounds per acre per year) of biomass in coastal scrub.Because biomass decreases by about 90 percent forevery step up the food pyramid, total animal biomassdepends upon such productivity. Consequently,chaparral also supports more animal life than coastalscrub and desert communities, but fewer animals thanCalifornia’s wetter forests. Although many chaparralcommunities provide abundant berries, seeds, andacorns for primary consumers, there may also be freshherbs and flowers, especially in new growth after fires.

Because annual droughts with literally no rain maystretch from April or May into October or November,water is often the most important limiting factor for thesurvival and growth of plants and animals. This favorsthe survival of animals that can slow their metabolismto hide from drought or travel greater distances insearch of water.

Many species wander into chaparral from adjacentplant communities. Most coastal scrub animals may

also thrive in chaparral habitats where they will findless open space, but more protective cover.

Smaller Animals of the Chaparral. Most chaparralbirds have the advantage of flying to distant watersources. Like many other animals, they are often dullbrown or gray for camouflage in the dry, drought-tolerant foliage. California’s state bird, the Californiaquail, is common in many plant communities and isfrequently seen scurrying through openings or cavitiesin the chaparral. This dark bird grows up to 39 cm (11inches) long. It waddles through the brush, eating veg-etation, seeds, and insects. California quail have aconspicuous reddish brown crown with a protrudingblack topknot feather that resembles a danglingminer’s head lamp pointing the way for the bird. Dur-ing severe drought years, some plants eaten by Cali-fornia quail contain larger amounts of chemicals thatinhibit quail reproduction.

The wrentit is a small bird who sings “The Song of theChaparral,” a call resembling the high-pitched bounc-ing of a ping-pong ball after it is dropped on a tilefloor, with smaller time intervals between successivebounces. It is quick and difficult to spot. The wrentit isjust one of the many animals that dine on abundantberries and insects in the chaparral. Other birds withdistinctive sounds include the morning dove’s “coo,”screeches of the cactus wren, and, at night, the deep“whoo” of the great horned owl. Along with the owls,red-tailed hawks and red-shouldered hawks areskilled and fierce predators. The list of other commonchaparral birds is a long one, including the rufous-sided towhee, California towhee, California thrasher,and scrub jay. Hummingbirds, such as Anna’s hum-mingbird, with its metallic red throat and crown andgreen back, are among the others.

Ants, grasshoppers, beetles, bees, and butterflies areamong the insects commonly seen that play impor-tant roles in chaparral communities. Arthropods suchas spiders and scorpions are seen as ferocious preda-tors by some smaller animals, but as scrumptiousmorsels by others. Smaller arthropods such as ticksand mites are also sources of food for some, but arefrequently annoying nuisances to many animals andhumans who may unknowingly gather them bybrushing against chaparral vegetation. By the twenty-first century, confirmed cases of Lyme disease fromticks caused concern among some California outdoorenthusiasts.

Reptiles are far more common in these dry habitatsthan amphibians, and most species are shared byother plant communities, such as the coastal scrub.The striped racer is a snake which races through the

chaparral with its head held high. Its sleek, longitudi-nal stripes may pass at speeds up to 7 km (4 miles) perhour, as it hunts many kinds of smaller animals. As thename implies, the common gopher snake (which onlylooks like a rattlesnake) is one of many species help-ing to keep rodent populations under control.

The western rattlesnake is one of the most commonof the chaparral rattlers, and it often has the typicaldiamond pattern on its back. After biting their prey,rattlesnakes often follow their victims to where theanimals finally drop from effects of the venom. Thereand then, dinner is served. Contrary to myth, fewCalifornians ever die from rattlesnake bites, exceptwhen small children or people with strong allergicreactions are bitten. The bites, however, can cause afew days of violent illness.

Larger Animals of the Chaparral. Though larger ani-mals are fewer and so are rarely observed, they maybe seen searching for smaller animals or various edi-ble plant parts in the chaparral. Small mammals, suchas woodrats, often represent food for larger predators.The California quail can become a meal for coyotes,foxes, bobcats, or even Cooper’s hawks. Where coy-ote may feed on almost anything at any time, thesmaller ringtail cats hunt birds late at night and may beattacked by great horned owls.

Mountain lions survive by ranging over large dis-tances of more than 256 sq km (100 square miles),hunting for mule deer and other larger animals. It is nosurprise that recent human encounters with mountainlions in California have been mostly in areas where


Figure 5-8 One of the most powerful predators in Califor-nia, the mountain lion, requires a large range. You will not getthis close to a wild cougar, nor will they want to get so closeto you. They are being sighted more often where suburbshave encroached into their hunting grounds.


there is accelerated human encroachment into wild-lands. The sensationalist media has exploited theseunfortunate events. However, in California, there hasbeen an average of only one mountain lion attack onhumans every few years. As expected, the smallerbobcat is restricted to smaller ranges of about 4 sq km(1.5 square miles) and usually to hunting smaller ani-mals, such as rodents and birds.

Mixed Evergreen ForestIn transition between the drier oak woodland and chap-arral communities and the wetter, more productivecoastal and montane coniferous forests are the mixedevergreen forest communities. In coastal mountains ofthe north, these forests are usually inland from the heav-ier winter rains, summer fog, and coastal coniferousforests. However, they grow closer to the coast com-pared to the oak woodlands even farther inland that

endure extreme drought and hot summers. In the west-ern Sierra Nevada and the southern coastal mountains,they appear higher in elevation, above the warmer, drieroak woodland and chaparral, but below the cooler, wet-ter montane coniferous forests.

Throughout California, where wetter coniferousforests might be expected, especially to the north, mixedevergreen forests may grow in patches on drier south-facing slopes and in nutrient-poor soils. Where chaparraland oak woodland are expected, especially farther in-land and to the south, patches of mixed evergreen standsmay appear in wetter, more productive sites, such asnorth-facing slopes. Nearly 5 percent of California is cov-ered by these mixed evergreen forest communities.

Habitat and StructureThe name, mixed evergreen forest, correctly suggeststhat most of the trees are hardwoods (especially oaks)that keep their leaves throughout the year. In California’s

The bear on California’s state flag will not be found in any ofthe state’s plant communities. The California Grizzly Bear(Ursus arctos) is extinct. They once roamed in large numbersthrough many California plant communities from the coastthrough lower-elevation inland regions. However, they weremost often spotted around grassland, chaparral, and wood-land communities. Their huge shoulders and claws wererarely used to rip apart larger animals. They were more com-monly used to dig for roots, tubers, smaller mammals, andcolonies of tasty ants and termites.

The grizzly is now remembered as a fierce and powerfulgiant—its average size was about 900 pounds—that washunted to extinction by the early 1900s. From the time ofSpanish settlement, grizzly bears were seen as dangerous ob-stacles to the expansion of California farm and grazing lands.Accounts of famous grizzly encounters and hunts started withthe Spanish and continued through the 1800s. The last grizzlyin southern California was probably spotted in the Santa AnaMountains before 1910. One report locates one of the lastCalifornia grizzly bears with her cub near Kings Canyon be-fore 1915. However, the last recorded grizzly bear killing wasin Sequoia a few years earlier. Most records confirm their ex-tinction by then, accelerated by the $10 reward received foreach dead bear. The subspecies relative of this bear survivesfrom the northern Rockies into Canada.

The California grizzly’s smaller and more docile relative—the Black Bear (Ursus americanus)—is common today, espe-cially throughout central and northern California’s forests andin many other productive plant communities. The blackbear’s diet is similar to its extinct grizzly relative: variouskinds of plants, berries, roots, tubers, and small animals.However, it lives in California’s cooler forests and sometimes

hibernates, habits that were not associated with the Californiagrizzly. The several black bears introduced from the SierraNevada to southern California’s San Bernardino Mountainssince the 1930s have thrived. By the 1990s, their populationhad swelled to more than 300 in that mountain range alone.

As more humans visit and settle in these marginally wildregions, more frequent bear encounters delight the sensation-alist Southern California news media. Each year, these blackbears wander out of the forest and into the urban fringe ofSouthern California’s inland valleys. They become the stars innews stories when they are filmed rummaging throughgarbage and even bathing in hot tubs in the suburbs. Whenone young boy was mauled while camping in the SanBernardino Mountains in July 1996, graphic pictures of the re-covering youngster’s wounds and film of the hunt for therenegade bear was one of the top news stories on local LosAngeles TV broadcasts for days. Increasing bear encounters inNorthern California are also making the news; they are alsothe result of encroaching developments.

These events are not new to Californians. After years ofrepeated encounters, nuisance bears learn not to be afraid ofhumans. They also learn to associate the presence of humanswith food. For years, bear management programs in parksand other wildlands emphasized the identification and tag-ging of problem bears who had become too “tamed.” Thesebears were usually transported back up to more isolatedwildlands, where it was hoped they would return to theirwild ways and natural diets. Unfortunately, many such bearshave stubbornly walked great distances right back to thenearest people. These bears, who have lost their ability tosurvive on their own, become dangerous to humans and areusually killed.

Bears and People

Mediterranean climates outside the wetter coniferousforests, most of these trees survive with sclerophyllous(hard) leaves, which help cut transpiration rates. How-ever, a greater variety of trees often mix in, includingnumerous conifers and broadleaf, winter-deciduoustrees, depending on moisture and soil conditions.Species common in the poor soils of the closed-coneconiferous forest communities may also be found here.Many understory species, such as those typical of thechaparral, commonly creep in from other plant commu-nities. It is not difficult to imagine this plant communityas a broad ecotone bridging its drier, less productive,and its wetter, more productive neighbors; it sharesspecies and structural characteristics (physiognomy)with them.

Plants. In central and southern California, mixedevergreen forest may include or be dominated byCoast Live Oak (Quercus agrifolia), Canyon Live Oakor Golden-Cup Oak (Quercus chrysolepis), or InteriorLive Oak (Quercus wislizenii). In the Sierra Nevadaand higher elevations of the Transverse and Peninsu-lar Ranges, the broadleaf, winter-deciduous BlackOak (Quercus kelloggii) may appear at the expense ofother species such as Coast Live Oak. These commu-nities are not only denser than California’s oak wood-lands, but they include many other tree species.

Madrone or Pacific Madrone (Arbutus menziesii) andTanoak or Tanbark Oak (Lithocarpus densiflora) areboth evergreen trees with large, oval leaves, butMadrone’s bark and flowers contribute to its likenessto a giant manzanita. Known as Oregon myrtle in Ore-gon and pepperwood in parts of California’s CoastRanges, the previously examined California Bay orCalifornia Laurel (Umbellularia californica) may have

the most pungent aroma of any tree in California’smixed evergreen forest. Big-Leafed Maple (Acermacrophyllum) not only displays its classic, giantpalmate leaves, but it is the largest maple in Californiaand may occur in mixed evergreen forests throughoutthe state. A quick look at this maple (especially itslarge leaves) reveals why it cannot survive on Califor-nia’s drier, more exposed slopes.

Conifers often associated with the yellow pine forestsmix in at higher elevations of the Sierra Nevada and insouthern California. Coulter Pine (Pinus coulteri), withits long, dull needles and giant cones, thrives in thesecommunities. Big-Cone Douglas Fir or Big-ConeSpruce (Pseudotsuga macrocarpa) grows only insouthern California, mostly on north-facing slopes. Itis far more adapted to drought and fire and has muchlarger cones than its relative, Douglas fir, which growsin wetter habitats to the north.

In California’s northern mixed evergreen forests,species that require more moisture usually join themix. Exceptions are found only on the driest, most ex-posed sites, where chaparral-like species such asHuckleberry Oak (Quercus vaccinifolia) are found.Also growing as shrubs among the oaks are Bush or Golden Chinquapin (Chrysolepis sempervirens).The leaves and structure of this member of the beechand oak family make it look right at home in drier,mixed evergreen sites. However, it is also found incompletely different communities, such as in highelevations of the Sierra Nevada. Its relative, GiantChinquapin (Chrysolepis chrysophylla or Castanopsischrysophylla) grows as a much larger tree in wettermixed evergreen sites and even into redwood forestcommunities. As yellow pines become more com-


Figure 5-9 Mixed forests along the Salmon Riverin northern California may exhibit many differentspecies. This is in a transitional landscape away fromthe coast, but not so far inland to produce a strongrainshadow. The canyon, with its water sources,grows a thicker forest cover than what you mightfind on more exposed slopes. High country is in thedistance.


mon, they are joined by other conifers, includingSugar Pine (Pinus lambertiana), Knobcone Pine (Pinus attenuata), Western White Pine (Pinus monti-cola), and Incense Cedar (Calocedrus decurrens).

However, when species such as Douglas Fir (Pseudot-suga menziesii), Port Oxford Cedar (Chamaecyparislawsoniana), Western Hemlock (Tsuga heterophylla),and Grand Fir (Abies grandis) become more com-mon, they indicate a transition into the wet, lushcoastal coniferous forest communities found only onthe northwest coast. Soil chemistry may become theimportant factor for location of many of these species.On the wettest slopes, especially in the Klamaths, thefast-growing straight and tall Douglas fir often domi-nates and may even be joined by an occasional CoastRedwood (Sequoia sempervirens). In these ecotonesbetween the marginal and most productive plantcommunities in California, species distributions aredetermined by distance from the ocean, soil, slopeangle and aspect, disturbance from fire or logging,and numerous other factors. The truly diverse andcomplicated “mixed” evergreen forest lives up to itsname.

Accompanying this plant diversity is an often abundantand wide variety of animals. An example of the varietyof foods available to animals is the Oregon White Truf-fle (Tuber gibbosum). This tasty underground mush-room is one of many important fungi that grow in thesoil and on the roots of trees below the mixed evergreenforest. They also serve as treats for rodents, such as thegolden-mantled ground squirrel.

Animals. Most animals of mixed evergreen forests arequite common in surrounding plant communities.Mice, chipmunks, chickarees, and squirrels are typi-cal small mammals here. The western gray squirrelprefers to eat acorns, so its nests are often found in oaktrees. The tree canopy provides protection fromhawks and other predators as this skilled climber witha large bushy tail darts up and around the trees gather-ing and stashing acorns. Raccoons make their homesin tree cavities and roam at night for a wide variety offood. Their comical-looking facial markings resemblemasks. Even their eating habits, such as washingthemselves and their food when water is availableduring dinner, can be entertaining.

There are numerous members of the weasel family inCalifornia, especially in different plant communitiesof the northwest. Many of them are fierce predators;they are usually more common near water. Rarelyseen in the northwest forests are wolverines, badgers,fishers, weasels, martins, and minks. Rare river otterlive in burrows out of the water. Skunk are more com-

mon; their famous scent glands and thick fur on longbodies with short legs are characteristic of the weaselfamily.

Mule deer graze throughout California, and they fre-quent mixed evergreen forests. They eat fresh sproutsand herbs and often establish noticeable grazing linesmarking the upper limits of their reach. This abundantanimal is the only native deer in California. Their num-bers were once controlled by mountain lions, but thepopulation is often decreased by hunting today. Likemany wild animals, the behavior of these graceful deermay change as they are exposed to humans who maythink they are “cute.” Humans who try to befriend andfeed deer and other wildlife in California put the ani-mals at risk. The animals may turn away from their nat-ural diets and methods of getting food, often leading topoor nutrition and more dependance on humans. Thiscan be dangerous for people as well; even deer have,when cornered, defended themselves and kicked andkilled startled tourists in places like Yosemite.

As many as 100 bald eagles nested in California in thetwenty-first century, while more than 600 winter inthe state each year. Most concentrate just south of theOregon border, especially in the Klamath River areawhen salmon or steelhead are abundant. They may beseen perched on taller trees and snags near rivers andin plant communities such as mixed evergreen forests.By the late 1960s, their nesting numbers had droppedto twenty after heavy hunting and concentrations ofDDT had nearly destroyed reproductive cycles. Sincethe protection given them with enforcement of the1972 Endangered Species Act, bald eagle populationshave dramatically rebounded so that they have beenseen as far south as the Mexican border.

Coastal Coniferous Forest CommunitiesFrom the Oregon border to Big Sur, California’s coastalconiferous forests represent the southern extension ofsome of the most impressive temperate rainforests in theworld. Though these forests were and are more exten-sive from coastal Alaska through western Washingtonand Oregon, they are just as impressive and containmany of the same species where they are strung alongCalifornia’s north coast. Because they contain the tallestliving trees in the world, it could be argued that portionsof California’s coastal forests are even more spectacular.

Habitat and StructureParts of these forests are scattered all the way to the sea,but they are usually located slightly inland from thestronger winds and salt spray coming off the beach.They grow from the western slopes of the Klamathssouth into the northern and central Coast Ranges. In the

north, where average precipitation may reach 250 cm(100 inches) per year, these forests cover all the slopesdown from exposed ridges on fertile soils. At the south-ern edge of their range, near Big Sur, where precipitationdrops to near 50 cm (20 inches), these forests only growat the bases of wetter north-facing slopes and withincanyons. The northwest coast also has the shortest sum-mer drought in California; rainy seasons usually start ear-liest and end last here.

The effects of summer drought are also curbed by thepersistent summer fog and stratus which hugs the coast.Not only does this maritime air keep summer tempera-tures cool and relative humidities high, decreasing evapo-

transpiration rates, it also results in fog drip that can actu-ally add some moisture to the soil during periods withoutprecipitation. Up to 25 cm (10 inches) of fog drip per yearhas been measured beneath forest canopies along parts ofCalifornia’s coast. The maritime air also moderates wintertemperatures so that snow is rare and temperatures sel-dom drop below freezing. With abundant water and mod-erate temperatures, there are few limiting factors. Conse-quently, where soils are favorable, production is higherhere than in any California plant community.

Plants. Botanists often divide these plant communi-ties into two segments. The north coast coniferous


TALLEST TREES IN THE WORLD

Native stands of Coast Redwood (Sequoia sempervirens) arescattered from the southwestern tip of Oregon along coastalslopes south to Big Sur. Coast redwood is endemic to this re-gion, but it was more widespread across the western UnitedStates during glacial periods. Ice Age fossil remains of coastredwoods have been found as far south as Los Angeles, whereit apparently grew within local canyons. Today, it is restrictedto the immediate coastal slopes inland to about 16 km (10miles), except to more than 32 km (20 miles) inland wherecoastal fog and stratus are siphoned with sea breezes throughmajor west–east canyons. The transition from dense coastalredwood forests to drier forests to oak woodland and evendrier communities often within several kms (miles) from westto east is remarkable. South of the Bay Area to Big Sur, coastredwood is usually restricted to patches in local cooler, wettermicroclimates.

The tallest trees were cut decades ago before they wereprotected. However, remaining virgin growth is protectedin today’s state and national parks, and trees can reachhigher than 110 m (360 feet) to become the tallest trees inthe world. A young redwood’s growth may average morethan 0.5 m (1.5 feet) per year for more than a century. Insome areas, 4,525 kg/ha (4,000 pounds per acre) per year ofadded growth accumulates the greatest total above-groundbiomass known to California—up to 346 kg/sqm (1,500 tonsper acre).

Native redwood stands are dependent on many other fac-tors besides heavy winter rains, persistent summer fog, andthe absence of prolonged frost. In river valleys, spectacularfloods may leave thick silt deposits, destroying other species,but the coast redwood thrives by growing new shallow rootsystems higher on the trunk.

Fires usually burn around the fire-resistant bark, clearingthe surface of competitors and leaving open soil where newredwood seeds may sprout and seedlings thrive. Chemicals inthe thick bark also discourage insects and diseases from harm-ing redwoods. Consequently, the world’s tallest trees may livefor more than 2,000 years (though the bristlecone pine in theWhite Mountains is the oldest and Sequoiadendron gigan-

teum in the Sierra Nevada has the greatest mass). When coastredwoods finally burn or are cut, they vigorously sprout fromstumps. Individual trees often grow from rings of intercon-nected stumps and roots.

Figure 5-10 California’s coast redwoods are the tallesttrees in the world. They usually grow where there are heavywinter rains, persistent summer fog, and rich alluvial soils.

Montane Coniferous Forest Communities and Above: An Overview 149

forest communities include a wide variety of speciescommon to the Pacific Northwest coast, but they donot usually include coastal redwoods. The coastalredwood forest shares some of the Pacific Northwestcoast species, but it has its own characteristics and isexclusively Californian. We will examine the coastredwood only after looking at some of the other com-mon species in California’s northwest coastal forests.

Even the names of the species indicate that these areusually stately trees more common to the cool,damp forests farther north, forests with few rivals onEarth. Grand Fir (Abies grandis), Sitka Spruce (Piceasitchensis), and Western Hemlock (Tsuga hetero-phylla) may dominate and be joined by other treessuch as Western Red Cedar (Thuja plicata) and PortOxford Cedar (Chamaecyparis lawsoniana). Hard-wood species may grow on the fringe of or representan understory below these forests. Big-Leaf Maple(Acer marcrophyllum), California Bay or Laurel(Umbellularia californica), Madrone (Arbutus men-ziessii), and Tanoak or Tanbark Oak (Lithocarpusdensiflora) are examples.

Below these canopies, the ground cover must beadapted to constant damp conditions with filteredlight at best. Herbs such as Redwood Sorrel (Oxalisoregana), shrubs such as the various wild berries, andnumerous fern such as Bracken Fern (Pteridium aquil-inum) and Sword Fern (Polystichum munitum) arecommon. A water-loving, velvety coating of greenmoss seems to cover every surface from rocks to treesto bare ground. Fires may clear out these understoryspecies and logging opens the forests to successionalspecies adapted to more light and less moisture.

The two most common trees growing in these forestsare also the most important to California’s timber in-dustry. Douglas Fir (Pseudotsuga menziesii) andCoastal Redwood (Sequoia sempervirens) may befound separately or mixed together. They grow fast,straight, and tall and provide high-quality, valuablewood which has many uses. Because Douglas firgrows—along with other species such as Red Alder(Alnus oregana)—as a natural successional species, itis preferred by the timber industry when replantingafter logging an area. Because most of northwesternCalifornia’s private and public forest lands are nowtree farms, successional species such as Douglas firare far more common than before logging began.

Currently, more than 90 percent of California’s origi-nal forest lands have been logged at least once. Thismeans that if you are wandering through a Californiaforest, you are likely to be viewing at least a second-or third-growth stand. If you have the opportunity to

visit the less than 10 percent remaining of California’struly old-growth forests, you are in an environmentmore representative of California’s past. Many ofthese remnants are protected in California’s parks andwilderness areas, but some of them are at the center ofcontroversies pitting the timber industry against thosewho want to save the trees. Perhaps such controversyover so little land illustrates the enormous value of thistimber and the pressures and conflicts that will con-tinue as so many interests ask for more from the state’sprecious resources.

Animals. Termites and other insects join the fungi andother decomposers to recycle decaying organic debrisin California’s north coastal forests. Slimy, shell-less,bright yellow banana slugs grow up to 15 cm (6inches) long as they ooze among and devour decayingorganic debris in moist forests. Many kinds of mois-ture-loving salamanders, birds, and mammals, includ-ing the black bear, are also found here.

Once often seen foraging along boundaries betweenthe north coastal forests and their meadows fromnorthern California to Canada, Roosevelt Elk (Cervuselaphus roosevelti) numbers also declined rapidlyuntil recently. Also known as wapiti (Shawnee forwhite rump), males grow spectacular antlers and mayweigh up to 450 kg (1,000 pounds). These territorialbulls are famous for their violent battles, when theycharge and lock horns during the fall rutting season.Dominant bulls may win control of more than tencows. The few remaining herds are added attractionsfor wildlife enthusiasts among the big trees. A fewmembers of its smaller subspecies relative, the RockyMountain Elk (Cervus elaphus nelsoni), remain in iso-lated sections of northeastern California.

� MONTANE CONIFEROUSFOREST COMMUNITIES ANDABOVE: AN OVERVIEW

Various montane coniferous forest communities growon mountain slopes from above about 300 m (1,000 feet)in the north to above 1,500 m (5,000 feet) in southerncismontane California. Sparser mountain forests may befound at even higher elevations in transmontane Califor-nia. In northwest California, montane coniferous forestsmay appear between the wetter forests to the west anddrier communities to the east. Such low elevations in therest of California are usually too dry to support pineforests, but from the Klamaths to the northern CoastRanges and from the Cascades to the Sierra Nevada,these communities are widespread. Farther south, conif-erous forest communities are more restricted to patchy

and isolated higher country, especially in the Transverseand Peninsular Ranges.

The various montane coniferous forest communitiescover nearly 20 percent of California. At higher eleva-tions, they grade into less productive alpine communi-ties above the tree line.

Belts of Vegetation Zones Across CaliforniaStarting in the transition above chaparral and oak wood-land communities, the first dry pines begin to appear onCalifornia’s mountain slopes where temperatures arecooler and precipitation is greater. At slightly higher ele-vations, these trees eventually grow together to form themixed coniferous/lower montane or what is also knownas the yellow pine forests. Moving farther up, coniferousforest species more common to wettest montane habitatsare found at even higher, cooler elevations.

In high country above these lusher forests, annualprecipitation begins to decrease again, producing less-dense stands of shorter trees more tolerant of prolongedfreezes and snowpacks. We have now passed throughthe red fir/lodgepole pine communities, into the sub-alpine forest. Finally, at highest elevations, even dwarfedtrees disappear in the harsh, exposed terrain of theAlpine Zone above the tree line. In transmontane Cali-fornia, including the rainshadow sides of California’smajor mountain ranges, these plant communities or veg-etation zones are usually squashed closer together andtilted up into higher elevations. Our review of theseplant communities begins at lower elevations and worksinto the highest California terrain.

Mixed/Lower Montane Coniferous ForestsHabitat and StructureLower or mixed montane coniferous forest communitiescover about 10 percent of California. Tree height is usu-ally not as impressive as in the northern coastal forests.Outside the giant sequoia forests, tallest trees may growup to 60 m (200 feet). Undergrowth ranges from sparsein drier forests and poor soils to tall, dense, thick shrubsand small trees, often with species more common to ad-joining plant communities. Hardwoods such as oaksoften join the pines. In drier environments, the needle-leaf tree species tend to have much larger cones andseeds, increasing their chances of survival in adverseconditions.

Most of the soils are made of porous materialsweathered from especially granitic bedrock, and theytend to reflect the acidic nature of the pine needleswhich accumulate and decay on the forest floor. A vari-ety of herbs, grasses, and spring wildflowers are com-mon below breaks in the canopy, especially after fires,

but they turn brittle and brown by the end of the summerdrought. Fire has played an important role in determin-ing the physiognomy and species distribution withinthese mixed montane coniferous forest communities.

These communities could be considered to bewithin the Transition Life Zone above the drier UpperSonoran Life Zone communities and below the colderparts of the Canadian Life Zone. More generally, theseforests are found above California’s flat valleys andbelow the more exposed, steep, rocky slopes of higherelevations. This explains why they are sometimes calledlower montane forests. Another common name is yellowpine forest, which technically refers to forests dominatedby ponderosa, Jeffrey, and sometimes coulter pine.However, this label is often also used to describe moun-tain forests with similar physiognomy, but different dom-inant conifers. You can see why these communities aresometimes labeled as mixed montane coniferous forests.In this section, we will start with the lower, drier pinesand generally work up into the higher, cooler, wetterforests. With so many different dominant species, it willbecome obvious why there is so much difficulty agree-ing on one name for these communities.

Plants. Often growing among the chaparral and oakcommunities is Gray (Digger) Pine (Pinus sabiniana),which was examined in a previous section. CoulterPine (Pinus coulteri) is especially common in openstands along the boundaries of dry pine forests fromthe Bay Area south into Baja. Like gray pine, it haslong needles, but they are darker green. Coulter pinesgrow the largest cones in the world. In lower elevationopen forests of southern California on wetter north-facing slopes and in protected canyons usually aboveabout 900 m (3,000 feet), they may grow near Big-Cone Douglas Fir (Pseudotsuga macrocarpa). Some-times called big-cone spruce, this is related to theDouglas fir of the north except, as expected in thedrier south, its cones are much larger.

Ponderosa Pine (Pinus ponderosa) and Jeffrey Pine(Pinus jeffreyi) look much alike and form similarforests. Like coulter pine, both are three-needle pines,but Ponderosa Pine has large plate patterns on itstrunk. It also grows sharp spines turning out from itssmaller cones, earning its other name, “prickly pon-derosa.” Jeffrey Pine has long, narrow ridge patternson a bark that smells like vanilla or butterscotch whensniffed. Its cones grow spines turned inward. Pon-derosa is the most widespread pine in the westernUnited States and is vital to the timber industry.

Because Jeffrey Pine survives colder winters with av-erage January temperatures less than �1�C (30�F),more severe drought, and even lightning strikes, it ismore common in the challenging higher elevations to



the north and drier forests into Baja. Even in the Kla-maths, Jeffrey Pine grows with chaparral on the driestsites and poorest soils. In the Warner Mountains inCalifornia’s northeast corner, Jeffrey Pine grows atlowest, driest sites. It yields to Ponderosa on higher,wetter slopes, which yields to washoe pine (a rareryellow pine of the western Basin and Range) aboveabout 2,600 m (8,000 feet). These Washoe Pines(Pinus washoensis) grow here with the most extensiveQuaking Aspen (Populus tremuloides) woodlandsaway from riparian habitats in California. Such im-pressive stands of aspen suggest environments similarto the Rocky Mountains, where there is less summerdrought. Aspen are also noted for their extensive net-works of interconnected tree roots.

Shifting west, Douglas Fir (Pseudotsuga menziesii) isrestricted to moist forests throughout northern Califor-nia and was discussed with the north coast coniferousforests. Its cones hang down from drooping limbs.Sugar Pine’s (Pinus lambertiana) numerous clumps offive needles make bushy stems. These are the tallestpine species in the world (up to 75 m (245 feet) andthey grow some of the longest cones—more than 30cm (12 inches) in length. The attractive sugar pine wasnamed for its sweet sap. It is widespread throughoutCalifornia’s conifer forests. In contrast, Pacific Yew(Taxus brevifolia) is a rare, slow-growing coniferfound in deep shade of old-growth forests only innorthern California and beyond. This tree became fa-mous when the National Cancer Institute announced

that chemicals from its bark and roots inhibit thegrowth of tumors.

Incense Cedar (Calocedrus decurrens), with its reddishbark, might be mistaken for small giant sequoia if itweren’t for its branching chains of leaves that resembleflat needles. White Fir (Abies concolor var. lowiana)invades wetter and higher yellow pine forests through-out northern and southern California. This white firmay become dominant above yellow pine forestswhere average annual precipitation is more than 100cm (40 inches). Its white bark and rows of short nee-dles that point up from the stem make it easy to iden-tify. Surprising relic stands of white fir atop the NewYork, Clark, and Kingston mountain ranges in the east-ern Mojave are actually a Rocky Mountain varietyknown as Abies concolor var. concolor. These treeswere stranded and then isolated on high north-facingslopes of these desert mountains with other speciesduring the last several thousand years as California cli-mates became warmer and drier.

To illustrate the diversity and complexity of Califor-nia’s montane coniferous forests, note that several ofthe previously discussed species are among the six-teen conifers growing within a 2.6 sq km (1 squaremile) area near Russian Peak in the Klamath NationalForest of Siskiyou County, southwest of Scott Valley.This may be the greatest variety of different coniferspecies growing naturally within any area of its size inthe world.

Owls and Timber

ployment were broadcast by the media from traditional smallCalifornia timber towns.

As the economies of these small California towns sufferedinto the twenty-first century, timber industry executives andemployees searched for and found their perceived enemies inthose who regulated cutting. There was little honest debateabout the future of California’s forests, while the mediathrived on the simplistic war they helped create. (By the late1990s, pairs of northern spotted owls were observed adaptingto life in second-growth forests.)

With continued habitat destruction, it was no surprise thatnumbers of the California spotted owl, a different subspecies ofthe northern spotted owl, were also decreasing. It often makesits home in older, larger trees in mountain forests farther in-land, such as in the Sierra Nevada. In January 1993, the NationalForest Service slowed logging in many of these forests to keepthe California spotted owl from becoming threatened and toavoid renewed confrontation between timber interests and en-vironmentalists. However, the timber industry still complainedabout the further loss of short-term revenue.

Due to destruction of up to 90 percent of its preferred habitat,the Northern Spotted Owl (Strix occidentalis caurina) wasclassified as a threatened species by the federal government in1990. These owls prefer to nest in the larger, taller trees, espe-cially in old-growth forests, but their numbers dwindled asdecades of intensive logging replaced old growth with treefarms. To environmentalists, the spotted owl was just one ofmany indicators of California’s vanishing old-growth forests.As the owl’s threatened status was used to help slow cutting,the bird represented a roadblock to the timber industry in itsefforts to access remaining old-growth stands for the sake ofshort-term profits.

This controversy boiled over into a media-hyped andoversimplified national debate about “jobs versus the environ-ment.” It happened to coincide with a nationwide recessionand retooling from labor-intensive to high-tech logging prac-tices by larger timber firms. Instead of focusing on rational dis-cussion and debate about long-term habitat and watersheddestruction and sustainable yields for a healthy, long-lived tim-ber economy, emotional images of lost jobs and soaring unem-

Plants Closer to the Ground. It was previously men-tioned that a number of hardwood trees, shrubs,herbs, grasses, and wildflowers common in otherplant communities may mix with the conifers in thesetransitional montane coniferous forests. Such speciesas Black Oak (Quercus kelloggii), a common andwidespread winter-deciduous tree with large-lobedleaves, adds to the fall colors and contributes to diver-sity throughout California’s mountain forests. It oftengrows on drier sites and south-facing slopes adjacentto wetter coniferous forests along with species such as

Canyon Live Oak or Golden-Cup Oak (Quercuschrysolepis).

On the mountain forest floor, about thirty-four speciesof paintbrush (Castilleja spp.) grow in nearly everyCalifornia plant community; their flowers add delight-ful color below the forest fringe. They photosynthe-size like most plants to produce food, but they are alsopartially parasitic as they attach to roots of shrubs tosteal moisture and minerals. In many species, thebright red colors actually come from large, leaf-like


Largest Trees in the World

quality wood saved the remaining groves from destruction untilconservationists were able to protect them in national parks.Most of the older trees finally die when their crowns becometoo heavy and they fall over. Today, the extensive shallow rootsmay be trampled by visitors, weakening the anchoring systemsand making some of the trees more vulnerable to topple.

Giant Sequoia (Sequoiadendron giganteum) grows only inabout seventy-five mostly small groves on the western slopesof the Sierra Nevada. Perhaps the most spectacular of Califor-nia’s numerous endemics, it is the largest (but not the tallest)living thing on Earth. Giant Sequoias only grow on the wetterslopes above about 1,350 m (4,400 feet) and below about2,600 m (8,500 feet) in the western Sierra Nevada, often inhabitats with and similar to white fir. They are also relics of awetter period, when they grew down to about 900 m (3,000feet) elevation and were far more widespread. They are re-stricted to slopes that were not carved by glaciers.

Many of the largest trees are more than 60 m (200 feet) tall,weigh more than 1,000 tons, and are more than 2,000 years old;some are more than 3,000 years old. Many of the largest are inSequoia National Park’s Giant Forest, where the General Sher-man Tree stands more than 83 m (273 feet) tall. The GeneralGrant Tree in adjacent Kings Canyon National Park is more than81.5 m (268 feet) tall with a 12.3 m (40.3 feet) diameter base.Growth rates for some young trees are up to 60 cm (2 feet) peryear, which are some of the fastest rates in the world. Howhave these ancient giants grown so tall and survived so long?

They thrive on moisture from winter’s heavy orographicprecipitation. Snow packs average more than 3m (10 feet) bywinter’s end, melting into deep soils where giant sequoias’ ex-tensive shallow roots are anchored. They survive summerdrought by growing in moist, sheltered sites. Their bark is upto 60 cm (2 feet) thick, and it is resistant to fire, insects andparasites, fungus, and disease.

The first branches and exposed living portions of the gi-ants are usually near the top, high above the reach of groundfires. Heat from occasional ground fires opens cones to shedseeds, while the flames on the forest floor leave soft, nutritioussoils and clearings where new seedlings can get plenty of sun.Fire is also important to clear the forest of smaller plants andtrees such as white fir, which, if too tall, could direct fires in aladder effect toward the higher living crowns of the giant se-quoias. This is one reason why suppression of fire in theseforests actually threatens the giant sequoias. Control burns andmanaged wildfires should increase the health of these forests.

Loggers began to cut these giants by the 1870s. When thegiant sequoias fell, however, their wood splintered into myriadpieces. Though many trees were cut for scrap uses, the poor

Figure 5-11 After measurements proved sequoias in Se-quoia and Kings Canyon National Parks to be the largest treesin the world, they were given names, such as this GeneralSherman Tree.


bracts, which look like brushes dipped in paint, fram-ing the much smaller flowers.

Snow Plant (Sarcodes sanguinea) does not photosyn-thesize, but it attaches its roots to and feeds off fungiwhich break down decaying organic material in thesoil. Its peculiar bright red stalks grow up to one foot(30 cm) out of the spring snowmelt. Pinedrops(Pterospora andromedea) is another mycotrophic orsaprophytic plant that looks like a skinny version ofsnow plant but has no roots and simply steals directlyfrom fungi associated with other plants. These andother mycotrophic herb species are common in moist,shady spots below the forest floor where layers of or-ganic materials accumulate and decay. They are alsocommon below the canopy of red fir forests at higherelevations.

Animals. Just as these environments support inter-mixed plant species, they are also home to a mixtureof critters that are common to adjacent lower- andhigher-elevation communities. Review the animalssurveyed in lower-elevation communities (such asoak woodland and chaparral) and in higher-elevationcommunities for a glimpse of these animals.

Red Fir and Lodgepole PineForests/Upper Montane ForestsHabitat and StructureWe now move to higher elevations above the giant treesand denser montane coniferous forests to more exposedmountain slopes. In northern California mountains, wemust first pass through the often cool, dense growth ofthe red fir forests, where annual precipitation is greaterthan any other mountain community. Here, the colder

temperatures, heavy snows, and shorter growing sea-sons prohibit many lower elevation species from invad-ing. More than 150 cm (60 inches) of precipitation mayfall each year in wetter sites, with total snow falls up to13 m (more than 42 feet) per year building snow packsmore than 4.5 m (15 feet) high by winter’s end.

Above about 2,500 m (above 8,000 feet) elevation,moving toward the Subalpine Zone, lodgepole pine maybecome more dominant, as precipitation decreases withheight. Because lodgepole pine survives harsher condi-tions, it often replaces red fir in waterlogged soils atlower elevations or on more rocky sites exposed to thecolder climates of higher elevations. At even higher ele-vations in southern California, more prolonged summerdrought prohibits growth of red fir. Here, upper limits ofmontane coniferous forests often blend directly intolodgepole pine forests. Red fir often mingles with upperlimits of the montane coniferous forests in northernmountains, and lodgepole pine may be common inhigher subalpine communities. However, these twospecies often mingle in the north to form a separate plantcommunity between the communities above and belowthem. Merriam may have labeled this community as partof the Canadian Life Zone; others have used the term“Upper Montane Forest.”

Plants. The two varieties of California’s Red Fir (Abiesmagnifica) are widespread in northern California highcountry but grow only a short distance into southernOregon and western Nevada. Red fir often replaceswhite fir at higher northern California elevations. Ithas redder bark, larger cones, and more rounded,shorter needles than white fir. It is also a commonChristmas tree known as “silver tip.” Growing onwell-drained soils usually above about 1,600 m(5,000 feet) and below 3,000 m (10,000 feet), it may

Figure 5-12 Deer graze in a mountain meadownear Medicine Lake in northeastern California. Thismountain rises up above drier Modoc country. Atthese higher elevations, cooler temperatures andmore precipitation support conifer forests withpine, fir, and hemlock like the one in the distance.

tolerate cold better than any other conifer. Noble Fir(Abies procera) replaces it in the Klamaths; CascadeFir or Lovely Fir (Abies amabilis) takes over north ofCalifornia’s Cascades. Both are very similar to red fir.

Red fir and lodgepole pine stands are frequently struckby lightning. Fires caused by lightning may clearpatches of these trees so that local regrowth is usuallythe same age. Though lodgepole pine may grow insunny clearings caused by recent fires, it is often re-placed by red fir, which thrives in shadier habitats es-tablished many years after fire.

Varieties of Lodgepole Pine (Pinus contorta) are wide-spread throughout western North America. The vari-ety murrayana grows from the higher forests of theKlamaths and Cascades as low as 1,800 m (6,000 feet)and into the Sierra Nevada up to 3,600 m (12,000feet), usually above red fir forests or where soils aretoo waterlogged or dry to support the less versatile redfir. In the Peninsular Ranges, upper limits of montaneconiferous forests change to lodgepole pine at higherelevations. Lodgepole’s name refers to the structuralsupport it provided for California Indian homes. It hasa white bark with scales, needles in clusters of two,and small, sharp cones. The tallest lodgepole pinesgrow up to 30 m (nearly 100 feet) in the most mature,healthy stands. It and red fir often represent the high-est elevation stands of dense, tall trees in California,but lodgepole pine grows in more adverse conditions.

Small stands of Quaking Aspen (Populus tremuloides)may join lodgepole pine in wetter riparian habitats.Resembling but growing above sugar pine in morerocky, exposed soils into subalpine communities isWestern White Pine or Silver Pine (Pinus monticola).It grows square plates on its bark and its branchescurve up; it grows much smaller cones than sugarpine. In contrast, stems of Mountain Hemlock (Tsugamertensiana) and its cones droop down. Other treessuch as Western Juniper (Juniperus occidentalis occi-dentalis) and Jeffrey pine also grow on more exposedslopes, joining red fir and lodgepole pine into the sub-alpine communities.

Yellow-green staghorn lichens grow on the trunks ofmany trees down to the average snow accumulationline, which may be more than 4.5 m (15 feet) fromground level. Dark, shady conditions, bitter cold, andheavy snows inhibit understory growth in red fir andlodgepole pine forests. Shrubs are often restricted toopenings below an otherwise dense forest cover. Theyinclude mountain species of manzanita (Arctostaphy-los spp.) adapted to cold and snow. Mountain or BushChinquapin (Chrysolepis sempervirens) is found in sev-eral other California plant communities with its spinyfruits bearing nuts eaten by squirrels and bears. Currant,

mountain berry, and other shrubs are joined by herbsand summer wildflowers, which may be more com-mon in coniferous forests of lower elevations or in sub-alpine communities at higher elevations. Mycotrophicor saprophytic plants, similar to those examined as partof the coniferous forest ground cover, annually springup through late spring’s melting snowpacks, below thedenser red fir or lodgepole pine canopy, where abun-dant organic debris has accumulated.

Animals. One of the most notorious animals livingwithin these communities is the Lodgepole NeedleMiner (Coleotechnites milleri), the larvae of a smallmoth. The moths are abundant in August when theylay their eggs, which later hatch into small caterpil-lars that will bore into the needles of the lodgepolepine. In large numbers, they may kill the trees, leav-ing open patches of dead pines to be followed bymore diverse species and the eventual return oflodgepole pines. Some early forest managers, seeingthis as an unfortunate waste of valuable timber, un-knowingly sprayed infested forests with DDT andother poisons to control the “pests.” Many of themore than forty predators that kept needle minernumbers under control (including gleaning birds,such as mountain chickadees, wasps, and other in-sects), were also harmed by the spray; this createdeven more serious long-term problems.

The Mountain Chickadee (Parus gambeli), a smallgray bird with black and white bands on its head, isjust one of many birds living in these forests. It is amodel gleaner, a bird that climbs up and down treespicking insects from bark. It lives in many differentCalifornia forests and woodlands and requires somepatience to spot. Its lonely three-note call is a familiarmood-setter in a quiet forest. Mountain bluebirds,Clark’s nutcracker, sapsuckers, woodpeckers, and nu-merous cone crackers are among the list of birds seenand heard in these communities. Great horned andpygmy owls swoop down on rodents and other smallanimals for dinner.

Mice, pocket gophers, shrews, and ground squirrelspopulate the forest floor. There are eight differentspecies of chipmunks in the Sierra Nevada alone.These are actually small squirrels, and each inhabitsdifferent communities. In these high-altitude zoneswith deep snow, gray squirrels are replaced by chicka-rees, which live in trees above the snow pack and feaston pine and fir seeds. Black-tailed jackrabbits are re-placed by snowshoe hares, which are more skilled athopping through deep drifts. Other larger animals in-clude weasel, fox, coyote, and black bear. Marten orpine marten are large weasels that attack and feed onsmaller mammals such as squirrels and chipmunks.These long, short-legged animals are quick and



deadly hunters through the trees and deep snow; theirthick fur is well suited to long, cold winters.

Subalpine ForestsHabitat and StructureWe now venture still higher to California’s subalpine for-est communities. Though some of the species creep upfrom the red fir and lodgepole pine forests, all plants andanimals must be specially adapted to the long, bitter-coldwinters. Here, summer growing seasons may last only 7to 9 weeks, and frost is common even then. Subalpineforests grow at elevations just above 2,000 m (6,500 feet)in the Klamaths, but they grow at higher elevations in-land in the Cascades. This is also true in the SierraNevada, where the most extensive subalpine communi-ties are found in California. On isolated southern andeastern high mountains, these plant communities beginas high as 3,000 m (nearly 10,000 feet). Because very littleof California’s topography has been lifted to such high el-evations, it follows that these plant communities repre-sent a very small percentage of the state. Due to suchharsh conditions, the biomass and species diversity is lim-ited compared to most other California communities.

In all locations, subalpine forests’ upper limits markthe tree line, where environmental conditions are soharsh that trees cannot survive. Above the timberline,temperatures could drop as low as 40 degrees below 0�F.The harsh winter may be followed by quick snowmeltrunoff and severe summer drought where poor soils areoften incapable of supporting tree growth.

Below tree line, on wetter slopes to the north, precip-itation may reach 125 cm (nearly 50 inches), or it may av-erage below 70 cm (28 inches) in isolated southern andeastern highlands. Almost all precipitation falls as snow,except for the few summer showers in the north and a fewsummer thunderstorms in the south that break the shortwarm season’s drought. Soil water is frozen throughoutthe year, except for the short summer, when snowmeltmay quickly run off exposed, rocky surfaces only to belost to lower elevations and forests. High winds are a con-stant challenge to life, especially during winter.

Subalpine species may be most interesting due totheir ability to survive in such harsh environments.These are communities where desiccating winds driveice pellets to form flag trees. Their windward sides lookblasted, battered, and bare, with more protectedbranches on the leeward sides growing and pointingaway from the prevailing winds. Terms like krummholz,a German word for bent or twisted wood, describe thetortured nature of some of these stunted species. Theyare often dwarfed to the height of the average snowpack. Any tree that grows above this line is exposed tothe deadly, fierce, cold blasts of winter or to the violentavalanche. When soils finally thaw, some plants evenphotosynthesize in the dim light below the protectivesnow cover.

Though many trees are dwarfed to near shrub size,true shrubs are not common in subalpine plant commu-nities. Some shrubs may be more typical of the snowyforests at lower elevations. Summer’s herbs, grasses, andwildflowers must quickly spring from melting snows,grow, bloom, and return to seed before autumn’s firstheavy snow. Many of these species are also common inhigher alpine communities and are especially dense inwell-watered mountain meadows.

Plants. Mountain Hemlock (Tsuga mertensiana) growsmostly on wetter sites in northern California subalpinecommunities and is widespread throughout the north-western states. Needles grow out from all sides of itsbranches; it looks like a fir but is actually a pine. White-bark Pine (Pinus albicaulis) also grows in the north andinto the Pacific Northwest, but Limber Pine (Pinusflexus) grows on drier, rocky slopes in central and south-ern California and into highlands of the southwesternstates. Both of these trees have long needles at the endsof stems and may look like lodgepole pine, but theirneedles are in clusters of five instead of two.

Its common name, Foxtail Pine, describes the needle-covered branches of Pinus balfouriana. This speciessurvives only where summer showers break thedrought in the Klamaths and where summer thunder-storms occasionally dump rain on the southern SierraNevada. Evidence for the slow growth of many treesin these forests is found in a few foxtail pine measuredat more than 3,000 years old. The largest junipers inthe world grow in the Sierra Nevada and some speciescreep into California’s subalpine communities, butthey often become twisted testimonies to the torturouslife on these exposed slopes. Several trees of the red firand lodgepole pine forests, such as western whitepine, are also found in subalpine communities.

Great Basin Sagebrush (Artemisia tridentata) is one ex-ample of the few hardy shrubs from other plant com-munities that have invaded and adapted to theseadverse subalpine environments. In moist habitats,high-elevation species of willow, mountain berries,herbs, and wildflowers common to alpine communi-ties may be established.

Great Basin Bristlecone Pine (Pinus longaeva) is a sub-alpine tree growing near the timberline in California’shigher transmontane mountains. It often grows nearlimber pine, but in poor soils weathered fromdolomite. Bristlecone pine is found in the White, Inyo,and Panamint Mountains with limber pine, but itgrows alone on higher and nutrient-poor dolomiticsoils and in the Last Chance Mountains. Some bristle-cone are the oldest trees on earth; the oldest has beengrowing in California’s White Mountains for morethan 4,600 years.

These are the harshest subalpine conditions, whereextreme winter cold combines with extreme droughtin the rainshadow of the Sierra Nevada. Nearly allprecipitation falls as snow and much of that subli-mates in the windy, dry conditions that follow. Bristle-cone pine may look somewhat like foxtail pine, buteven foxtails could not survive these harshest of habi-tats. Somehow the gnarled, dwarfed bristlecones sur-vive. In these environments of ultra-slow growth anddecay, scientists have used downed wood, Carbon 14dating, and tree rings from bristlecone pines to traceclimate and timberline variations back 8,000 years.

Animals. Many animals living in California’s sub-alpine communities may also be found either in thelodgepole pine and red fir forests below or in thealpine communities above. Numerous species mi-grate out by winter to escape the deadly cold. This in-cludes as many as thirty species of birds. Perhaps themost notorious and commonly heard is the noisyClark’s nutcracker. These are large gray jays withwhite markings on black wings. Because Clark’s nut-crackers may store more than 30,000 seeds per seasonin caches of fifteen, many subalpine pines rely onthese birds to disperse and plant their seeds, whichmay produce seedlings, which eventually grow inclumps. This is similar to the clumping of oak trees incommunities at much lower elevations, caused whengray squirrels bury acorns and do not retrieve them.

Meanwhile, other birds such as bright blue mountainbluebirds may be spotted on tree tops or hoveringabove the unsuspecting insects that will serve as theirnext meals. Most of these birds migrate to lower eleva-tions or to southern latitudes for the winter.

Mountain Juniper (Juniperus occidentalis ssp. aus-tralis) grows conspicuous nutritious fruits with seedsthat may not germinate unless they have passedthrough the digestive systems of birds or mammals.This helps disperse their seeds and eventuallyseedlings into different plant communities. Just as in-sects, mice, chipmunks, squirrels, birds, and other an-imals depend on subalpine plants for survival, so dothe plants often benefit from the activity of these ani-mals. These relationships will be considered in moredetail in the next section on alpine communities.

Alpine CommunitiesLess than 1 percent of California has been lifted to eleva-tions above the tree line. On these isolated islands in thesky, terrible cold and wind create such harsh conditionsthat even dwarfed trees cannot survive. The tree linemay drop down to nearly 2,000 m (about 7,000 feet) inthe Klamaths, but it is a little higher on Mount Shasta,

Lassen Peak, and in the Warner Mountains. The timber-line continues to tilt upward from the northern SierraNevada south until it approaches 3,350 m (11,000 feet) inthe southern Sierra Nevada. It is slightly higher in thedrier White and Inyo Mountains to the east. Only threesolitary spots of alpine communities emerge just abovethe tree line in southern California: at more than 3,000 m(10,000 feet) near and on the Transverse Range peaks ofSan Antonio and San Gorgonio, and on the PeninsularRanges’ Mount San Jacinto.

During the Pleistocene Epoch Ice Age, when many ofthe northern highlands were covered with ice, these alpinecommunities extended down more than 1,200 m (4,000feet) elevation to include nearly 10 percent of the state.

HabitatPrecipitation continues to decrease with elevation gainfrom the subalpine; annual totals up to 100 cm (40inches) are common in the central Sierra Nevada, withmore precipitation in the Klamaths and less to the southand east. Almost all precipitation falls as snow; even theoccasional summer thunderstorm may produce hail,sleet, and snow. Winter temperatures below �18�C (0�F)are common, and temperatures frequently drop belowfreezing even on summer nights. Winter snows will buryplants in drifts that may not melt until late summer.Then, intense summer sun can dry and damage plants.

Fierce winds will then batter plants in exposed sitesand intensify evapotranspiration rates as the dry, rar-efied air blasts through. Following the summer thaw,snowmelt rapidly drains down rocks and porous re-golith into the forests below. This leaves alpine com-munities stranded without water during the shortestgrowing seasons in California, ranging from one to twomonths. The only exceptions are in meadows and lakeswhere water has been dammed. Most soils are rocky,poor, acidic, and unproductive. Though trees are elimi-nated, an amazing variety of life forms are successful inthese habitats.

Often referred to as the Alpine Zone, C. Hart Mer-riam placed these communities in the Arctic-Alpine Zone(above the Hudsonian Zone), while some generalistssimply call it tundra. It is not surprising that plants similarto California’s alpine communities grow in the far northlatitudes of North America’s tundra, also beyond the tim-berline. Other plants, adapted to summer’s drought, arerelated to those in California’s driest deserts. You mayfind many of the more than 600 species of hardy alpineplants in other California communities. About 200species grow only in alpine habitats. Here, we can onlybegin to look at the structure of these communities and afew of the species surviving in them.

Plants. Perhaps the most hostile of California’s envi-ronments are on the bare, exposed, rocky alpineslopes known as alpine fell-fields. Clinging to these



surfaces with little or no soil are sometimes densemats or cushions of growth. Lichen is found wherefungus can anchor in and gradually weather rock andwhere algae can join to carry out its role of photosyn-thesis. In cracks and sheltered spots, perennial pros-trate plants hug the surface but grow more extensiveroot and subterranean stem systems below. Theseplants lie ready to grow and flower as soon as theshort, unreliable mid-summer growing season begins.They join annual herbs to produce spectacular wild-flower displays. Many of these species have the largeflowers required to quickly attract pollinators. Variousgrasses and sedges may join the crowd to help captureand protect finer particles from erosion.

Sunflowers, buckwheats, and lupines are among thehundreds of common plants here. Species namesoften reflect the nature of the plants and their habitats.Paintbrushes include Alpine Paintbrush (Castillejanana). Various phlox include Coville’s Phlox (Phloxcovillei), while Pussy Paws (Calyptridium umbella-tum), Evening Primrose (Oenothera xylocarpa), thebright blue flowers of Sky Pilot (Polemonium exim-ium), and bright yellow sunflowers of Alpine Gold(Hulsea algida) are among numerous flowers addingcolor to California’s otherwise barren summertimealpine landscapes.

In and near alpine meadows, water is available for alonger period into the growing season and soils areusually better developed. Grasses and sedges may ac-cumulate to form dark sod or even peat bogs in wetterlocations. A few shrubs growing near these meadowsinclude heather and willow. The edges of meadowsare first to erupt in summer wildflowers, a splash ofcolor which shifts toward herbs near the center of

meadows within a few weeks. Many of these mead-ows were once lakes and are continuing through theirsuccessional stages. At lower elevations, lodgepolepine or other dwarfed trees may eventually encroach;in driest high country, annual grasses and sagebrushscrub may invade. But, in most of California’s highestcountry, communities resembling alpine tundra areusually the climax. Avariety of species growing in somany changing habitats demands more attention thanis possible in this fleeting sweep through California’splant communities.

Animals. Many larger animals and birds are capableof migrating from the alpine to lower elevations dur-ing winter. The California or Mountain Bighorn Sheep(Ovis canadensis californiana) is one of three sub-species of California’s bighorns that were once farmore numerous. Most mountain bighorn live in thecentral Sierra Nevada, but there is a small herd in theWarner Mountains. They once migrated to lower ele-vations, such as the Owens Valley, during winter, buthuman barriers and activities have impeded these mi-grations. Diseases, habitat destruction, and overgraz-ing by domestic livestock greatly reduced their num-bers in California to about 350 by 1990, promptingwildlife biologists to implement programs to savethem.

More abundant deer also migrate to lower slopes dur-ing winter. Birds have the advantage of migratingrapidly to feed on seeds and insects of the alpine andthen leaving to escape harsh conditions ushered in bywinter. The gray-crowned rosy finch is the only birdthat nests in the alpine, but it will fly down the eastslopes of the Sierra Nevada during harsh winterweather.

Figure 5-13 This view looks over conifer treetopsfrom lower elevations toward higher Sierra Nevadaenvironments. High country rocky slopes in the dis-tance are above tree line. They represent hostilehabitats where only the hardiest plants and animalscan survive.

Other animals, such as most rodents, hibernatethrough the winter. This state of slowed metabolismhelps them conserve resources and body fat accumu-lated during their summer and fall food-gatheringfrenzies. Among the mice, gophers, chipmunks, andsquirrels is the approximately 25 cm- (10 inch-) longBelding’s ground squirrel; it may be seen on rocks inthe central Sierra Nevada, screaming alarm calls towarn of a possible incoming predator. It hibernates forup to 8 months, living off body fat from summer’sseeds and insects.

The largest squirrel of the Sierra Nevada is the plumpand furry-tailed yellow-bellied marmot. It can growtwice as long as Belding’s ground squirrel and weighmore than 10 pounds just before the long winter hi-bernation begins. Numerous marmot heads may beseen protruding above rocks. Their loud whistles alsowarn of possible dangers.

A few animals remain active in winter. The pocket go-pher burrows through the substrate, eating roots andother plant parts buried under the snow. Pikas, alsoknown as cony or chief hares, are the size of rats buthave rounded ears and no tail; they look like and aremore related to small rabbits and hares. They collectand guard piles of nutritious herbs near their rockyshelters so that they may snack and survive throughthe winter. Pikas also make territorial calls when ap-proached, unless the predator is a marten or long-tailed weasel, which are capable of navigatingthrough the rock cavities in quick pursuit. When theseskilled predators are hungry, the only way to escapebeing served as the next meal may be to run for it!Though the white-tailed jackrabbit is seen in driersouthern Sierra Nevada and Great Basin alpine habi-tats, northern California’s snowshoe hare usually re-mains below the tree line. Both of them change colorto blend with seasonal backgrounds.

� RIPARIAN COMMUNITIES

Any habitat or community located on or adjacent to ariver bank or other freshwater body is considered ripar-ian. Because water availability is usually the most impor-tant limiting factor for most California plants and ani-mals, it is not surprising to find the greatest biomass andspecies diversity in riparian communities. Especially to-ward southern California, water shortages limit thegrowth and survival of plants and animals; remarkablechanges in the size, diversity, and density of organisms isstriking along water courses.

This is where coarse-grained soils often containabundant nutrients and organic materials. This is whereplant roots and animals can search out year-round

sources of surface, soil, or shallow groundwater. This iswhere explosive growth and successful reproduction areencouraged by the abundance of fresh water instead ofbeing limited by its scarcity. This is where the plants andanimals closer to water courses must adapt to periodicflooding and sediment deposits, and this is wherewildlife will find abundant food, water, and shelter.

Riparian Habitats and StructuresThere is an astounding variety of riparian communities incismontane California. Some are narrow strips along tinyseasonal streams or in deep, narrow canyons. Some arewide, sprawling swaths of forests adjacent to major peren-nial rivers that seasonally flood across broad valleys. Themost impressive riparian forests were the extensivegallery forests up to 16 km (10 miles) wide that pouredinto the Central Valley along meandering rivers spillingout of the Sierra Nevada. Some of the largest Valley Oaks(Quercus lobata) grew in these forests. Today, less than10 percent of the original 400,000 ha (about 1 millionacres) of Central Valley riparian woodlands remain.

Throughout California, whether riparian communi-ties have taller shrubs, small trees, or towering giants,they are relatively moist, cool, shady, protected habi-tats. Brief exceptions may be noted in winter wheredominant broadleaf deciduous trees lose foliage andopen the surface to sunlight. This also explains whyCalifornia’s brightest fall colors are seen along its ripar-ian woodlands.

Generally, the presence of water encourages the es-tablishment of plant and animal species typical of wettercommunities, and the differences are more dramatic insouthern California. In contrast to much of the state, sum-mers are more productive in riparian zones becausewater remains available; winters are least productivewhere broadleaf deciduous trees common to ripariancommunities become dormant. Though humans havegreatly reduced riparian communities to less than 1 per-cent of the state, these areas attract constant attention asthey contain some of California’s richest assemblages offlora and fauna and its most precious commodity—water.

Today’s remaining riparian communities continue toslice and meander through every California plant com-munity. They range from moist, dense redwood forestsgrowing in fresh, wet sediments in northwestern Califor-nia to ribbons of noticeably thicker and taller shrubs lin-ing the washes of southeastern California deserts.

Plants. Many different species of willow (Salix spp.)grow with their characteristic elongate leaves in ripar-ian communities from the coast to the highest moun-tains back down into the hottest deserts. Dependingon the species and habitat, they may grow as prostrateshrubs to dense thickets of large shrubs to tall trees upto 10 m (more than 30 feet).


Riparian Communities 159

ECOLOGIC ISLANDS

There is one big advantage of using generalists’ past attemptsto classify California’s plants and animals into overly simplifiedbiomes or vegetation zones—they often provided structureand organization to clarify what many saw as too confusingand complicated. Though there is still healthy controversy, inthe last few decades a confusing array of conflicting informa-tion about the biogeography of California has been studied,debated, agreed upon, and reorganized.

The old methods may be likened to grouping everyonewith the same skin color or accent in California into the sameculture or assuming everyone from the same culture has thesame lifestyle and habits. This is where overgeneralizing maybecome meaningless and counterproductive. Even most gen-eralists now agree that to understand the diverse plant and an-imal communities in California, we must go far beyond thefew generalized biomes and vegetation zones. This section isdevoted to ecologic islands because they are examples of ex-tremely important plant communities that are too easilyoverlooked using those old methods of classification.

HabitatsEcologic islands include habitats which are isolated and dif-ferent from their surroundings, and they may appear in anyportion of California for many reasons. They could includecliffs or talus slopes in the midst of otherwise gentle topogra-phy. They could be sources of fresh water in an otherwisexeric (dry, desert-like) landscape. Many such factors, and theplant communities that result, are examined in other parts ofthis chapter. Commonly in California, they are edaphic com-munities, where a sudden change in the chemistry of the soilor water eliminates some plant and animal species and allowsothers to successfully compete. (Edaphic refers to the natureof the soil.) Because great geologic diversity in this state hasproduced so many different types of adjacent rock outcrops,soil chemistry can radically change over very short distances.A good geographer or any other scientist must consider thesefactors when examining the distribution of plants and animalsin California.

When more fertile soils grade into serpentine or othersoils low in nutrients and high in heavy metals, or to highlyacidic soils such as mountain spodosols (podzols) or clay ox-isols, they present new challenges to plants and the animalsthat depend on them. More than 200 plant species and vari-eties are endemic on serpentine soils alone in California. Inpoorer soils, California’s densest forests may become open,while more open forests may abruptly turn to woodlands orchaparral; woodlands may turn to grasslands or drier xeric en-vironments in poor soils. Bald Mountain in northwestern Cali-fornia serves as a classic example. There are so many rare andendangered species in California partly because humans haveso frequently modified or destroyed these isolated, uniquehabitats.

These ecologic islands are scattered in tiny patchesthroughout the state. Because they are found in some form inevery region, and because they include so many endemic, in-

teresting, and sometimes well-known and unusual species, wecan focus on just a few of them. We will lump them with someother species which were otherwise skipped in our sweepthrough cismontane California communities.

Plants. Closed-cone coniferous forest communities are usu-ally restricted to poor soils where lusher forests would other-wise thrive. The cones open after many years from the heat offires to finally disperse seeds on freshly burned soil. Thesetrees usually form a more open canopy and often have othercharacteristics linking them to drier habitats. They may growwith chaparral and coastal scrub capable of surviving more ad-verse conditions. Most of these trees grow in relic standswhich were much more widespread when California climateswere cooler and wetter thousands of years ago.

Knobcone Pine (Pinus attenuata) is probably the mostwidespread example and is scattered from the Klamaths tosouthern California. This species survives in some of the driestclimates and poorest soils of any California pine, usually inlandfrom the immediate coast. It is often surrounded with otherforest species in northern California, but with non-forestspecies in southern and drier sites. There is a greater variety ofcoastal closed-cone pines—including Shore Pine (Pinus con-torta ssp. contorta), which is a relative of lodgepole pine—growing on coastal dunes and cliffs in northern California.Other examples include Bishop Pine (Pinus muricata) andthe sometimes twisted and scraggly-looking Monterey Pine(Pinus radiata) of central California and the Channel Islands.Interestingly, Monterey pine has been introduced as a timbercrop to replant some Southern Hemisphere forests, where itgrows taller and straighter than in its marginal California habi-tats. By the late 1990s, California’s Monterey pines were prov-ing how vulnerable they can be in such marginal environ-ments. They were the first pines to be decimated by thespreading pine pitch canker. Some biologists warned that upto 80 percent of Carmel’s pines could be wiped out by the fun-gus within 30 years.

Torrey Pine (Pinus torreyana) protrudes above thecoastal scrub in northern San Diego County and is also foundon Santa Rosa Island. It has that typical dry pine look butgrows needles in clusters of five. It is probably saved fromsummer drought by the cool coastal fog and stratus. The ap-proximately 9,000 trees only at these two sites make Torreypine the rarest pine in the world.

Eight of the ten species of cypress (Cypressus spp.) inCalifornia are endemic (restricted to California). They arealso divided into coastal and inland species and usuallyoccur in isolated patches. These are the trees with scale-likeleaves and fleshy cones which sometimes resemble tiny soc-cer balls. Monterey Cypress (Cypressus macrocarpa) is con-fined to the Monterey Peninsula on sites with granitic soil,persistent fog, wind, and salt spray. In spite of these restric-tions, the contorted and tortured images of these trees ap-pear in countless photographs and paintings as contrast tothe scenic coastline.

The four species of alder in California may be impor-tant nitrogen fixers in nutrient-poor soils. The morecommon White Alder (Alnus rhombifolia) gives wayto a shrublike Mountain Alder (Alnus tenuifolia) athigher elevations. Big-leaf Maple (Acer macrophyl-lum) is a valuable hardwood, while the yellow woodof Oregon Ash (Fraxinus latifolia) is used for furniture;both also grow in canyons up into higher elevations.Box Elder (Acer negundo), California Bay or Laurel(Umbellularia californica), several species of oak(Quercus spp.), and other trees may all enjoy wetterhabitats found in riparian woodlands.

Western or California Sycamore (Platanus racemosa),like maple, has huge palmate leaves. It is restricted toriparian habitats and canyons of central and southernCalifornia. This is another relic species that was far

more widespread until the warmer, drier climatesafter the Ice Age stranded and isolated it in these moistspots. It can look somewhat out of place as it turnscolor and then loses its leaves just in time for the mildrainy seasons in lower elevation southern Californiacanyons.

Poplars require moisture and their different speciesare also separated by elevation. They include the Fre-mont Cottonwood (Populus fremontii) and the BlackCottonwood (Populus trichocarpa), which grows intohigher elevations and up to 50 m (more than 160 feet)tall with its silver-bottomed leaves. Cottonwood getsits name from the cotton-like white hairs of the femaleflowers that drift in the wind. Quaking Aspen (Populustremuloides) may dominate higher elevation ripariancommunities into eastern and northeastern California


ECOLOGIC ISLANDS (continued)

The most widespread inland cypress are the Sargent Cy-press (Cypressus sargenti) of the Coast Ranges and the Mac-Nab Cypress (Cypressus macnabiana) of northern California,which are usually restricted to serpentine soils. As the nameimplies, tecate cypress grows on poor soils in southern Cali-fornia past the Mexican border. Cuyamaca Cypress (Cupres-sus stephensonii) was originally thought to be endemic onlyto the southwestern slope of Cuyamaca Peak in San DiegoCounty, until individuals were reported in Baja. Regardless, itis the rarest cypress in California, and it grows into higher ele-vations where chaparral turns to conifer forest. Before thetaller of these trees was burned, they towered more than 14 m(46 feet) high. Occasional fire is an important factor in most ofCalifornia’s cypress stands, but if fires are too frequent, extinc-tion of the rarer and more isolated species may follow.

Numerous other California species occur only in ecologicislands. Furthermore, shrubs common to chaparral, such aschamise, and different species of ceanothus and manzanitamay be indicators of poor soils within otherwise more favor-able sites. Even the California oaks include scrub speciesadapted to more adverse conditions, such as Leather Oak(Quercus durata), with its curled leaves. Because CaliforniaHuckleberry (Vaccinium ovatum) is common on poor soilsin central California, it should be no surprise that nearly purestands of bishop pine (another dry habitat pine) grow onHuckleberry Hill near Monterey.

The Baldwin Lake Pebble Plains east of Big Bear Lake, An-ticline Ridge near Coalinga, Corral Hollow Ecological Reservesouthwest of Tracy, and Pine Hill in El Dorado County in theSierra Nevada are famous for their ecologic island status. Allhave assemblages of interesting, rare, and endangered plantsand animals adapted to unusually adverse conditions. Some ofthe most fascinating examples are in the dwarfed closed-coneconifer forests or pygmy forests on the Mendocino County

ecologic staircase. Here, hardpan soils stunt tree growth andchange the dominant vegetation from forest to shrubs.

Animals. As expected, numerous, mostly smaller, rare ani-mal species are associated with specific soils or plants withinthese challenging ecologic islands. They include many insects,amphibians, and reptiles. The smaller and more unique habi-tats are often home to smaller and more delicate populationsof rare animals. Other animals (especially larger mammals andbirds) may live and are often more common in adjacent com-munities, but they may migrate through and sometimes settlein these patches of California. Many of them are considered inother sections of this chapter.

MONARCH BUTTERFLIES (Danaus plexippus) could bethe only insects which make lengthy, round-trip migra-tions; they may travel up to 4,800 km (3,000 miles), butover several generations. Up to 5 million Californiamonarchs winter mainly on the central and southernCalifornia coast; individuals have been known to mi-grate more than 1,000 km (650 miles). Most Californiamonarchs spend their winters feeding on nectar, andmany can be seen in Monterey pine and eucalyptustrees. A close look at some trees at locations such asPacific Grove and Morro Bay might reveal many hun-dreds of monarchs covering the trees.

They begin their journeys toward the north and east inthe spring. They return to the California coast each fall.The monarch’s larvae feed off milkweed, then grow tolarger caterpillars, and turn to butterflies in about twoweeks. Though they are immune to the poisonous milk-weed, otherwise potential predators recognize them asdistasteful. This is just one example of how animals maymigrate into or through California’s ecologic islands.

Riparian Communities 161

and in isolated stands as far south as the SanBernardino Mountains. It is difficult to miss the whitebark behind light green leaves which wave and trem-ble in even the slightest breeze. After dropping theirleaves, aspen will survive the coldest winter tempera-tures California can muster; they put on some spectac-ular fall colors in canyons north of Bishop and inhigher terrain of the Warner Mountains.

Shrubs also often include willows. Mule Fat (Bacharisglutinosa) somewhat resembles willow. Like willow,sedges, and some other species that grow near flowingwater, mule fat easily bends during and adjusts fol-lowing major floods and submersions. A variety ofother shrubs found in this ecotone between dry landand water include dogwoods (Cornus spp.), oaks(Quercus spp.), gooseberries and currants (Ribesspp.), other wild berries, and wild grapes. Herbaceousplants are more common in recently disturbed sites;rushes, sedges, cattails, and many different wildflow-ers are on this long list of riparian species often grow-

ing in areas where recent floods have reworked anddeposited new sediment.

Animals. When larger animals and birds becomethirsty and hungry, they often venture into ripariancommunities from other habitats, knowing where togo for water and more abundant food. Numerous birdspecies migrating many hundreds of kms (miles) stopto rest or winter along California’s water courses. Theyjoin the great diversity and biomass of animals whospend their entire lives in the shelter of these produc-tive ecotones between dry land and water.

Many aquatic insects live their entire lives in or nearwater. Others, such as mosquitoes, damselflies, anddragonflies, may fly away as adults. When tempera-tures warm, the riparian scene is busy with flyingmoths, butterflies, wasps, and bees, and crawling withants and other insects, caterpillars, and worms. Be-cause there is no shortage of nectar and fresh greenshoots to choose from on the plants or in the soil dur-ing spring and summer, there is no shortage of primaryconsumers, including vegetarian birds.

The crawling and flying bugs become food for spiders,birds, bats at night, and other predators. Even fish dineon them when they venture too close to water. Fly-catchers, warblers, wrens, and flickers are among theenormous list of birds frequenting riparian communi-ties. Salamanders, reptiles, and rodents, such as miceand woodrats, become dinner for kites and hawks byday and long-eared and great horned owls at night.Several native and introduced frog species also repre-sent tempting morsels to larger animals.

Raccoon commonly settle in riparian woodlands,where they feast on most of the edible aquatic andland animals and plants. California’s native aquaticturtle, the Western Pond Turtle (Clemmys marmorata)lives in and around fresh water in valleys and moun-tains of cismontane California and locally along theMojave River. Because their activity levels rangesomewhere between lethargic and comatose, theirdiets are restricted to juicy plants and occasional in-sects or dead animals that cannot escape. If it couldnot withdraw into its hard shell, this species would beeasy prey for California predators looking for ascrumptious dinner. This is a very different speciesfrom the Desert Tortoise (Xerobates or Gopherus agas-sizii) of transmontane California and the many turtlesintroduced into the state.

Although beaver (Castor canadensis) were hunted fortheir pelts to near extinction by the 1900s, they maybe found today mostly in northern California valleyand mountain water courses, where they gather and

Figure 5-14 Wherever water appears in California, itseems to change everything. On distant slopes, bark beetlesare eating their way through southern California’s mountainforests. But, along the shores of little Lake Fulmor, deciduoustrees have lost their leaves for winter and a variety of otherwater-loving species crowd around the water.

feed on native vegetation. In the mountains, they willchew and fell trees such as aspen and willow to makedams. Ironically, in lowland waterways, where theyare called bank beaver, they are a nuisance when theyexcavate and burrow into river and stream banks de-signed to hold back water.

Coyotes, foxes, skunks, rabbits, and other larger mam-mals frequently visit riparian habitats. When it comesto animals, California’s riparian communities are likebustling cities filled with busy consumers, especiallyduring spring and summer months. Some animals takeup residence in the city; others commute in from adja-cent communities to do their business. If spring andsummer in the riparian resemble a weekday lunchhour in one of California’s downtown financial dis-tricts, could the winter lull resemble a weekend nightin that same financial district? It is ironic that Califor-nia’s thriving cities and the agricultural land requiredto support their human populations have especiallyexpanded, encroached upon, and destroyed morethan 90 percent of nature’s great riparian cities thatonce supported abundant California wildlife.

� TRANSMONTANE DESERTS

Here, we survey some of the most interesting and impor-tant features in the distribution of plants and animals liv-ing on the inland side of California’s great physical barri-ers. Plant communities in the rainshadow deserts ofCalifornia must be adapted to at least two climate ex-tremes. First, temperatures are not moderated by marineair. Diurnal and seasonal temperature changes are ex-treme, so plants must adapt to extremely intense solar ra-diation and hot temperatures on summer days followedby extremely cold winter nights. The difference betweenrecorded high and low temperatures in one year at onedesert location could be more than 56�C (100�F)!

Second, winter’s Pacific storms drop most of theirwater on the windward sides of the mountains, and asthe drier air masses finally flow down the opposite rain-shadow slopes, they are warmed and dried. Conse-quently, most California deserts have no trouble livingup to this oversimplified definition: true deserts receiveless than 25 cm (10 inches) of rain annually, while evap-otranspiration rates greatly exceed precipitation. DeathValley receives an average of less than 5 cm (2 inches) ofrain per year while potential evapotranspiration ratescan be more than 380 cm (150 inches). Similar condi-tions are common in other lower deserts of southeasternCalifornia, where more than one year may elapse with-out recorded precipitation.

Even in the cooler, wetter semidesert conditions athigher elevations, dry continental air masses rule andcontinentality controls climates.

Poor soils (some with high salt content), fierce, des-iccating winds, limited shelter, and dangerous exposureabove ground are just some of the harsh conditions inthe transmontane deserts. Plants and animals must adaptor die. Somehow, many species not only survive, butoften thrive in these adverse environments. However,unlike our review of many cismontane California plantcommunities, this section is not about great size, diver-sity, or biomass. It is about how hardy species haveadapted to the harshest of conditions in California’s spa-cious desert communities.

Our review of California’s biogeography has alreadyskipped or spread into transmontane California on atleast four occasions. You may recall the semidesertchaparral communities that spill over to the inland sidesof the Peninsular Ranges and Transverse Ranges into theedges of the Colorado and Mojave deserts. These chap-arral communities include manzanita, chamise, cean-othus, sugarbush, mountain mahogany, various scruboak, bush poppy, yerba santa, and many other familiarplants.

Some of these and other more desert-like communi-ties also creep along the edges of the southern SierraNevada and west into cismontane California’s westernTransverse Ranges and southeastern Coast Ranges. It isinteresting that this geologic pivot point (where the Gar-lock and San Andreas Faults, three mountain ranges, andfive physiographic regions meet) is also an ecologicalpivot point. The result is a fascinating mix of desert,semidesert, and cismontane plant communities withtheir plant and animal species. It is another example ofthe many connections between California’s diverse geo-logic features and climates and the plants and animalsadapted to these diverse settings.

We also surveyed the high pine forests of theWarner Range in northeastern California and the highersubalpine forests with the oldest trees in the Basin andRange east of the Sierra Nevada. Finally, we peaked atthe surprising stands of White Fir (Abies concolor ssp.concolor) isolated on high north slopes of the Mojave’sClark, Kingston, and New York Mountains. These treesform an open forest with piñon pine and other speciesfrom above 1,900 m (6,200 feet) to nearly 2,350 m (7,700feet). The total of nearly 1,200 white fir grow up to 20 m(65 feet) tall and some are more than 400 years old. Atthese lofty elevations, temperatures are cooler and win-ter snows and summer thundershowers are more fre-quent than in the hot desert communities below.

In this section, we remain mostly east of California’sgreat physical barriers. We will gradually drop belowpreviously mentioned and rare transmontane forests to-ward the warmer, drier, lower elevations. Plant commu-nities will change from desert woodlands to desert scrubas we travel from the north and/or higher elevations to-ward the south and/or lower elevations. Remember thatmoving north in California deserts usually means higher


Transmontane Deserts 163

elevations and colder, wetter conditions, except for thefew hot and dry deep valleys which finger north (such asDeath Valley). Moving toward the southern deserts usu-ally means lower elevations and warmer, drier condi-tions, with exceptions such as those isolated, highmountain forests poking up out of the Mojave.

Piñon Pine and Juniper Woodland CommunitiesThough less than 3 percent of California is covered withpiñon and juniper woodlands, they are distributedthroughout transmontane California above 1,200 m(4,000 feet) and below 2,400 m (8,000 feet). This placesthem below the wetter coniferous forests and above thewarmer, drier desert scrub. These dwarf forests arefound from the eastern Cascades and Modoc Plateau(where juniper usually dominate) south into the easternSierra Nevada (where piñon dominate) and into theBasin and Range, where they grow below the subalpineforests. Moving south, they are common on the easternslopes of the Transverse and Peninsular Ranges and onthose higher elevation desert slopes. They also creepwest into drier portions of cismontane California’s Trans-verse Ranges and southern Coastal Ranges, previouslymentioned as an important natural pivot point, wherethey intermingle with species more common to cismon-tane plant communities.

Habitat and StructureThe trees in these dwarf forests are often mixed. Theyrange from widely scattered stands of especially juniperless than 3m (10 feet) tall in lower, drier locations withpoor soils to denser forests of mainly piñon pine up to 15m (about 50 feet) at higher elevations with quality soils.The latter phase of these communities is clearly a cooler,

wetter semidesert, where annual precipitation could beas high as 50 cm (20 inches) and winter snow is com-mon. In these cooler, wetter environments, the juniperand mostly piñon woodlands have dense understoriesand may mix with species common in coniferous forests.In drier sites, the understory predictably consists of morewidely scattered, smaller shrubs and mostly annualherbs common to California’s true deserts. Regardless, itis often possible to observe from one location the forest-covered slopes above and desert scrub below; all of thisstanding within the usually dry, clean air of the transi-tional piñon and juniper woodland communities. Mostof these California plant communities are related to simi-lar communities throughout the Great Basin and Col-orado Plateau to the east.

Plants. Junipers (Juniperus spp.) are small evergreentrees of the cypress family. They have scale-like leaveswhich resemble flat needles, small juicy cones com-monly known as juniper berries, and aromatic, some-times twisted and contorted wood. Different speciesmay grow into stately trees or krummholz forms insome of California’s highest forests; others grow asshrubs on the fringe of California’s true hot deserts.Though species of widely spaced juniper are commonin northeastern California and even in subalpinezones of the Sierra Nevada, they are usually associ-ated with drier sites than piñon pine. Here, we focuson the more important transmontane species.

North of Bridgeport and often in the open, rollingcountryside of northeastern California well into Ore-gon and Nevada, is Western Juniper (Juniperus occi-dentalis var. occidentalis). Its close relative, Mountainor Sierra Juniper (Juniperus occidentalis var. australis)is found on high mountain slopes, especially in the

Figure 5-15 We have traveled down to the east-ern rainshadow side of the Klamaths. Though we arenear the Oregon border, the climate is much drierhere than on coastal slopes far to the west, on theocean side of the mountains. Here, drier sage mixeswith open woodlands and even the occasionalconifer, just to remind us we are far to the north.

Sierra Nevada. It is also found in parts of the Transverseand Coast Ranges around that previously identifiedpivot point. California Juniper (Juniperus californica)grows from the southern Sierra Nevada into southernCalifornia, and Utah Juniper (Juniperus osteosperma) isfound in the Great Basin, Mojave, and TransverseRanges.

The One-Needle or Single-Needle Piñon Pine (Pinusmonophylla) is the most common piñon pine in Cali-fornia, growing from the eastern Sierra Nevada andBasin and Range into that pivot point again and thensouth into Baja. Four-Needle Piñon (Pinus quadrifolia)grows from the Santa Rosa Mountains of the Peninsu-lar Ranges into Baja California, while Two-NeedlePiñon (Pinus edulis) is found only from the highermountains of the eastern Mojave, east into the south-ern Rockies. Hybrid trees with one to five needles maybe found where the single-needle piñon grow withother species.

Great Basin piñon and juniper woodlands often growwith high desert shrubs such as Great Basin Sagebrush(Artemisia tridentata), rabbitbrush (Chrysothamnusspp.), and Bitterbrush (Purshia tridentata). In theTransverse and Peninsular Ranges, semidesert chap-arral plants such as Desert Scrub Oak (Quercus tur-binella) and yucca (Yucca spp.) are common. Movinginto drier southern deserts, Joshua Tree (Yucca brevi-folia) and even hotter desert shrubs such as CreosoteBush (Larrea tridentata) begin to appear in the scrub-bier, sparse growth of piñon and juniper boundaries.

Animals. Animals may find fresh vegetation tobrowse and juniper berries, acorns, and other food inthe piñon and juniper woodlands. Piñon nuts (some-times called piñones) have been especially importantfor the wildlife and California Indians and are nowconsidered a delicacy in some modern recipes. Sev-eral species of birds include hairy woodpeckers,chickadees, warblers, and nuthatches. Like Clark’snutcracker, the pinyon jay has been known to trans-port and bury seeds in caches more than 13 km (20miles) from the producing trees. Unlike most jays, thepinyon jay has no crest and is duller gray and lessblue. These noisy birds move in flocks between treesand are particularly important in spreading and plant-ing piñon pine nuts that could grow to become thenext seedlings in these woodlands.

Numerous rodents may live in and around thesewoodlands, including a typically large-eared, white-footed deer mouse called the pinyon mouse. Othermice, great basin kangaroo rats, wood rats, pocket go-phers, chipmunks, and ground squirrels compete foravailable food. Usually nocturnal porcupines often

hide in trees during the day. These spiny creatures arerarely seen, except as road kills, especially in north-eastern California. They gnaw on young bark bywinter and eat fresh buds, leaves, and herbs duringsummer. Gray foxes, coyotes, bobcats, and mountainlions are occasional predators in these communities,while mule deer and pronghorn antelope browse onthe scrub understory. California Bighorn Sheep (Oviscanadensis californiana) often move down fromhigher Sierra Nevada terrain to escape winter coldand snow. Desert Bighorn Sheep (Ovis canadensisnelsoni) migrate to higher elevations to escape thedesert’s summer heat.

Joshua Tree WoodlandsThough a very small portion of California is covered withJoshua tree woodlands, they form some of the state’smore distinct and celebrated plant communities. It is saidthat stands of Joshua trees (Yucca brevifolia) sometimesoutline the boundaries of the Mojave Desert. They arescattered from the southern Owens Valley throughoutthe Mojave Desert and into southern Nevada and north-western Arizona at elevations above 600 m (2,000 feet)to about 1,600 m (just above 5,000 feet). These commu-nities are especially common north of the TransverseRanges, around the Antelope Valley, and in eastern Mo-jave’s ranges. In these cooler and wetter higher eleva-tions of the Mojave, winter frost and some snow arecommon. Joshua trees do not grow in the hot, dry habi-tats of lower deserts to the south; they are a certain indi-cator of high desert in the Mojave.

Habitat and StructureLike piñon and juniper woodlands, species from manyother communities grow with them. At higher elevations,they may creep into piñon and juniper woodlands. De-pending on geographic location, understory speciesfrom scrub communities such as sagebrush, blackbush,saltbush, or creosote bush scrub are common. Consider-ing elevation and geographic location, discussion ofJoshua tree woodlands should follow sagebrush scruband perhaps blackbush scrub communities as we workour way down to lower elevations. However, becausethese towering, ghostly figures form open woodlandsunique to the high deserts of the southwestern UnitedStates, they are addressed here.

During spring, especially following a good rainyseason, grasses, herbs, and sometimes spectacular dis-plays of wildflowers explode in new growth among the brush. Within weeks, these plants die back and go to seed, dried and brittled by the summer sun. Local, infrequent, and unreliable summer thunderstorms maydeliver short-lived downpours. However, unlike thegradual soaking common during winter’s cold rains andsnowmelt, much of the water from summer’s brief



storms may run off or eventually evaporate in the heat.Therefore, new growth and flowering usually peaks justwhen temperatures are warming in the spring.

Plants. This species of yucca got its common name,Joshua, from the Mormons, who associated its upliftedarms and old age with the biblical military leader. Thismember of the agave family is sometimes called treelily and should not be confused with the smaller,scrubbier Mojave Yucca (Yucca schidigera). It alsohas smaller leaves than most other yuccas. The trunk,limbs, and size of Yucca brevifolia easily qualify it as atree.

Younger trees grow for years as single poles up to 3 m(10 feet) before they bloom or feeding insect larvaecause them to branch out. Fresh new leaves are addedto the branches as the tree grows at the expense of thelower old leaves, which wither and eventually fall tothe ground. The long, thin, spear-like leaves added tothe length of each branch are a reminder that this is adesert tree. The largest trees grow more than 10 m (32feet) tall and wide, making them the largest floweringplants of the Mojave. Their large, white, lily-like blos-soms are more numerous when favorable spring tem-peratures follow soaking seasonal rains.

Numerous species of shrubs and herbs commonbelow the Joshua trees are usually members of desertscrub communities covered in the next section.

Animals. Joshua trees are recognized for supporting avariety of small animals, some of which are totally de-pendent on the tree for survival. A classic example isthe mutualistic symbiosis which benefits yucca moths(Tegeticula spp.) and Joshua trees. At dusk, the yuccamoth is attracted to the Joshua tree’s white blossoms.It flies from tree to tree, gathering the sticky pollenuntil it lays its eggs in the flower and pollinates its tar-geted plants. As the larvae grow and mature, they feedoff some of the developing fruit. These two speciesmust occur together.

Meanwhile, larvae of the giant yucca skipper andyucca weevil eat from fresh growth, and termitecolonies recycle nutrients as they feed off of and findshelter in the dried and downed wood at the base ofthese trees. Beetles and other insects are also commonamong the Joshua trees.

The desert or yucca night lizard is just one animal thatfeeds off these insects under the shelter of downedwood, while wood rats (also known as pack rats) piletheir nests at the base of Joshua trees. Various snakes,including the night snake, slither among the debrissensing out many of these smaller animals for a meal.

Woodpeckers also eat termites, but you will findmany other birds here, including up to twenty-fivespecies known to nest in Joshua trees. These includenorthern flickers, flycatchers, house wrens, and Amer-ican kestrels. The colorful black and yellow Scott’soriole makes its nest from yucca fibers and feeds offthe tree and its insects. On the hunt are red-tailedhawks by day and screech owls by night. Housing somany diverse, interconnected, and interdependentneighbors, the Joshua tree may display a unique mi-croecosysytem, if not its own microgeography.

Desert Scrub Communities OverviewVarious communities with vast, open expanses ofdesert scrub cover nearly 30 percent of California. Lackof water is the most important limiting factor. However,severe summer heat in the lower deserts, bitter wintercold in higher northern desert shrublands, and manyother factors combine to create some of California’sharshest environments. Climates are too harsh and dryand soils too poor to support even dwarf trees. Thesemostly transmontane communities are found in patchesin northeastern California, become more widespread inbasins east of the Sierra Nevada, and then completelydominate the landscapes of California’s southeasterndeserts.

These most challenging environments might be con-sidered antithetic to California’s north coast forest com-munities, where abundant water and mild temperaturesrule for most of the year, producing relatively impressiveaccumulations of biomass and greater species diversity.Some desert scrub communities are also found in thesouthwestern San Joaquin Valley, behind the rain-shadow of the Coastal Ranges.

Habitats, Plants, and Structures of DesertScrub CommunitiesSagebrush Scrub. Sagebrush scrub communities(sometimes known as Great Basin sagebrush scrub) arewidespread at highest desert elevations, especially inCalifornia’s northeastern deserts. Various rather evenlydistributed sagebrushes cast their dull gray-green shadesacross the landscapes into several other Great Basinstates. In California, these communities are common onwell-drained soil from above 1,300 m (more than 4,000feet) to about 2,300 m (7,500 feet), but locally they ex-tend much higher into the subalpine of eastern ranges.

Sagebrush survive in many different habitats, fromthe understory of transmontane woodlands and foreststo exposed range without a tree in sight. More commonin northeastern California and the Modoc Plateau andeast of the Sierra Nevada crest, they become more scat-tered toward the south and then isolated into the Penin-sular Ranges. They even extend into the TransverseRanges around that previously identified pivot point.

Most common and widespread from Canada to Mex-ico and east past the Rocky Mountains is Great BasinSage (Artemisia tridentata). Its long light gray leaves endwith three teeth, and it may grow more than 4m (13 feet)high, though it is usually a smaller shrub. Other sage-brush include the darker Dwarf Sagebrush (Artemisianova), Black Sagebrush (Artemisia arbuscula), which isanother dwarf species adapted to poor soils, and Silveror Hoary Sagebrush (Artemisia cana) in dry meadows.

Bitterbrush or Antelope Brush (Purshia glandulosaor tridentata) look like darker green Great Basin sage,but are often heavily overgrazed. Various saltbush(Atriplex spp.) become common in more alkaline soils inthese communities. Also common and well-known inthese communities are Rabbitbush (Chrysothamnusspp.), Hopsage (Grayia spinosa), and Mormon Tea(Ephedra viridis). Rabbitbush is also known as Mojaverubberbrush because small amounts of rubber can beextracted from it. It is a standout when its bright yellowautumn flowers protrude above this community. Mean-while, stems of the leafless Mormon tea can be boiled tomake a bitter drink with a stimulant.

Various bunchgrasses include Bluebunch Wheat-grass (Agropyron spicatum), and annual grasses aredominated by the introduced Cheat Grass (Bromus tecto-rum). Overgrazing has restricted distribution of manyspecies, but greatly increased the abundance of less tastysagebrush and rabbitbush, two plants that often domi-nate the scenery in these communities. Fire is alsochanging this community.

Blackbush Scrub. Blackbush (Coleogyne ramosissima)dominates these communities which are common at ele-vations just below sagebrush scrub, but above the lowerdesert communities such as creosote scrub (especiallyfrom about 1,200–1,800 m [3,900–5,900 feet]). Althoughtheir leaves are grayish green, these low shrubs lookblack from a distance, and they sometimes resemble an-telope bush. Often found between high and low desert,they mix with many other communities and species, in-cluding Joshua trees. Such plants as yucca, TurpentineBroom (Thamnosma montana), Burrobush or Cheese-bush (Hymenoclea salsola), Horsebrush (Tetradymiaspp.), and Winterfat (Ceratoides lanata) are common. Aconspicuous and interesting plant is the Paper Bag orBladder Sage (Salazaria mexicana). Like Mormon tea,its skinny green stems are usually leafless, but it grows itsseeds in thin, inflated, paper-like pods which easily floatin wind or water. Like many of these species, bladdersage is common in other desert scrub communities.

Shadscale Scrub. These communities are also oftenfound between the upper sagebrush scrub and lower cre-osote bush scrub communities. You may find them inmore alkaline soils throughout the Great Basin and onhigher, steep mountain slopes with rocky soils in the

southern deserts. They are scattered in and north of theOwens Valley and on rocky slopes of the Basin and Rangeand Mojave. These communities are sometimes lumpedwith and considered a part of saltbush scrub communities.This is because the Winter Fat (Ceratoides lanata) mem-ber of the saltbush family occurs with the dominant Shad-scale (Atriplex confertifolia). Joining them is a speciescommon in saltbush communities, but not itself in the salt-bush family—Bud Sage (Artemisia spinescens). Most ofthese species grow as small, compact plants less than 50cm (20 inches) tall with light-colored leaves.

Saltbush Scrub. Though saltbush scrub communitiesare common in higher salinity soils of lower desert plainsand basins, they are also established on rocky soils ofhigher desert slopes. Because they are found in variousadverse conditions growing in poor substrates, they mayoccur above or below creosote scrub and other commu-nities. We will look at them now and venture into the cre-osote and cactus scrub after we finish our descent into al-kaline basins. Joining the previously noted shadscaleshrubs and low-growing shrubs from other desert com-munities are other members of Chenopodiaceae, the salt-bush family, including Allscale (Atriplex polycarpa) andGreasewood (Sarcobatus vermiculatus). Desert Holly(Atriplex hymenelytra) grows whitish leaves with pro-nounced edges resembling holly. These attractive com-pact bushes stand out against darker backgrounds as ifplanted in desert gardens. The list of Atriplex specieswhich represent various saltbush is extensive. Saltbushscrub also shares a number of annual and perennialgrasses and herbs with other plant communities.

Tumbleweed (Salsola iberica) is an introducedweed from Asia also called Russian thistle. It thrives inareas overgrazed and near disturbed and irrigated farm-land. These roundish, thorny plants become dried anddetached, rolling with the wind and spreading theirseeds as they go. By the 1900s, they were widespreadthroughout the west and had become common nui-sances in saltbush scrub and many other California plantcommunities. Annoyed California residents have usedmany colorful names (such as “Volkswagen Eaters”) todescribe these uninvited guests who roll into yards oracross roads at the most inconvenient times and places.

Alkali Sink. By the end of the Ice Age, more than 10,000years ago, California’s great inland lakes were evaporating,leaving high concentrations of salt in the remainingtrapped ponds and in the basin soils. Since then, floodshave carried more minerals into inland drainage basinswhile still more water has evaporated from capillary actionbelow the surface. Concentrations of salts are left behindand only halophytes—salt-tolerant plants—can survive.

Moving down the better-drained desert slopes to-ward the alkali sink, the vegetation gradually changesfrom saltbush scrub to the most salt-tolerant halophytes.



These communities are spotty in lower basins of theBasin and Range through the Mojave and into the Col-orado Desert. They are closely related to, and sharespecies with, their coastal marsh counterparts. Althoughthese desert habitats experience much greater variationsin temperature, it is interesting that we have traveled sofar across California’s plant communities only to findsuch similar plants and habitats.

More saltbush with light-colored and scaly leaves in-clude Allscale or Cattle Spinach (Atriplex polycarpa) andWingscale (Atriplex canescens). As salt content rises tonear 1 percent, Seepweed, Inkweed, or Desert Blite, andSea Blite (Suaeda spp.) splash dark gray shades justabove the salt pans and once provided much of theblack ink for Native American art work. In saltiest condi-tions approaching 2 percent, Pickleweeds (Salicorniasubterminalis) appear with their leafless, sectioned,jointed stems. These succulents store water and drop ex-cess salt with their dead stems. Iodine Bush (Allenrolfeaoccidentalis) resembles pickleweed and is another com-mon halophyte in these salty brews.

Various rushes, reeds, and cattails grow in wetter lo-cations. Where water is near the surface, phreatophytessuch as Honey Mesquite (Prosopis glandulosa) can growtap roots down nearly 10 m (33 feet) deep. These winter-deciduous legumes grow small leaflets during spring andlong bean pods. They once represented an importantstaple food for California Indians and are still vital tolocal wildlife.

Scraggly but bushy Salt Cedar (Tamarix spp.) wereintroduced from Eurasia and have aggressively takenover near many water sources. They also have extensiveroots which can tap and deplete underground watersources as their leaves transpire tremendous amounts ofwater. These species may also be found in or near sanddunes where groundwater may be tapped. Efforts con-tinued in the twenty-first century to eradicate these waterbandits where they were threatening local aquifers.

Creosote Bush and Cactus ScrubThe Oldest Plants Are Also Common. We now skip

back above the salty basins but below the higher desertwoodlands and sagebrush scrub, mostly on well-drainedsoils. Here, the most common shrub throughout the Mo-jave and Colorado Deserts grows. Because Creosote Bush(Larrea tridentata) survives in many different desert mi-croenvironments, it is widespread and it may be the singleplant most people associate with California’s desert land-scapes. It does not tolerate the extreme cold and pro-longed frost of the higher desert terrain but, because itdoes tolerate extreme heat and prolonged drought, it isoften dominant in middle- and lower-elevation deserts.This leaves it a wide range throughout transmontanesoutheastern California.

It also means that it may creep into and mix withother desert communities; myriad other species, includ-

ing many cacti, may be associated with it throughoutthese various microenvironments. Creosote bush is com-mon in areas of the Sonoran Desert, where precipitationpeaks during the summer monsoon season. It alsothrives into California’s Mojave, where summer thunder-showers are infrequent and unreliable, and peak precip-itation occurs during the cool winter season.

The creosote bush grows small, dark green leaveswith thick waxy coatings that provide pungent aromasduring rainfall. The plant drops many of its leaves duringdrought, but after about 2.5 cm (1 inch) of rain, it growsfresh leaves and numerous yellow blossoms to attract pol-linators. Its roots expand out away from the plant, robbingsoil moisture from new growth which cannot compete.

The results are almost equally spaced bushes resem-bling a well-planned park environment. It has been dis-covered that rings of “clone” plants sprout from these ex-tensive root systems. When botanists consider all thecloned shrubs growing out from an original plant’s rootsystem to be the same plant, they are the oldest plants inthe world. One “King Clone” in Johnson Valley wasfound to be more than 11,000 years old and another nearYuma is even older.

Numerous other shrub species are associated withcreosote bush scrub in the Mojave Desert, includingplants more common in adjacent communities. Commonand scientific names often reveal characteristics of theseshrubs. White Bursage (Ambrosia dumosa) is a shortgray bush with small leaves that often grows with cre-osote. The peculiar inflated stems of little Bladderstem orDesert Trumpet (Eriogonum inflatum) often line dis-turbed sites such as roads like so many holiday decora-tions. Burrobush (Hymenoclea salsola) and various salt-brush (Atriplex spp.) are other members of the long listof shrub species.

Figure 5-16 Around Anza-Borrego Desert State Park, youwill find different species of cholla and barrel cacti, yucca,ocotillo, and other typical low desert plants. Here, extremesummer heat follows spring’s wildflower displays.

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Moving into the Cactus Scrub. Other species aremore common in the Colorado Desert and often associ-ated with cactus scrub. Desert Agave or Century Plant(Agave deserti) grows thick leaves from its base. Afterabout 20–25 years, it sends up a stalk which grows up to30 cm (12 inches) per day to blossom with large yellowflowers that attract bats. Jojoba (Simmondsia chinensis)grow from California’s lower Colorado Desert well intothe Sonoran Desert of Arizona and Mexico. It has flat,waxy leaves. Female plants produce fruits with the highquality oil harvested in today’s jojoba plantations scat-tered from southeastern California and beyond.

Brittlebush or Incienso (Encelia farinosa) drops itsleaves and becomes brittle during drought. It growsfresh leaves and is covered with brilliant yellow sunflow-ers after heavy rains. Other Encelia species are common.The tall, dead-looking, thorny sticks that radiate out fromthe base of the Ocotillo (Fouquieria splendens) andpoint up to 5m (16 feet) high are also drought-deciduous. After about 2.5 cm (1 inch) of rain, thesestems erupt with small green leaves on the side and bril-liant red tubular flowers at their ends to attract hum-mingbirds. Each ocotillo can repeat this cycle up toseven times/year.

The cactus family (Cactaceae) is represented so wellin these California communities that many biologistsplace them in a separate community. They are welladapted to compete in the hot, dry conditions of thelower desert but are not tolerant of prolonged frost or se-vere cold. By growing shallow, widespread roots, theycan gather water quickly during rare downpours. Theysurvive by storing water, reducing leaf surfaces, andgrowing spines and thorns for protection from desiccat-ing winds and intense sun. Their spines and the acidicnature of their stored moisture also protect them fromhungry and thirsty animals. They are most common onrocky or other well-drained surfaces of California’s lowerColorado Desert.

Barrel Cactus (Ferocactus acanthodes) is the largest,most robust of the common California cacti. It thrives inopen, rocky locations. Various species of cholla (Opuntiaspp.) are densely covered with spines and have commonnames which help describe them, such as Staghorn (Op-untia echinocarpa) and Teddybear Cholla (O. bigelovii).

Teddybear are sometimes called jumping cholla.When spiny sections break off, they might get caughtin an animal’s fur or in your clothes or skin. Thepainful barbs are difficult to pull out, but the attachedcactus sections may grow to new plants after they havebeen transported and dropped—an effective methodof dispersal. They don’t really jump, but they can beannoying to careless travelers. Some of the most im-pressive and accessible stands of these cacti are atCholla Gardens in southern Joshua Tree National Park,where some plants grow taller than the humans on thenature trail.

Beavertail Cactus (Opuntia basilaris) really grow bigpads resembling beavers’ tails. Different species ofprickly pear cactus follow their showy flowers withscrumptious red fruits which serve as feasts for wildlife.The famous Saguaro Cactus (Carnegia gigantea), withits massive arms twisting majestically skyward, is foundnaturally only in a few spots in California just this side ofthe Colorado River. You will find them especially east of114 degrees longitude in eastern San BernardinoCounty’s Whipple Mountains. They become common onwell-drained slopes in southern Arizona and northernMexico, where annual precipitation peaks during sum-mer. The exalted saguaro, often a symbol of the desertsouthwest, has been introduced into landscapes of theCoachella Valley and into films and pictures of southernCalifornia landscapes where it usually does not belong.

After it rains, most plants in these communities mustdisplay showy flowers to compete with other species forattention from pollinators. The list of ephemerals whichcontribute to colorful spring displays is far too long forthis review. Lupine, brome, gilia, pincushion flower,desert star, fiddleneck, popcorn flower, and many othercolorful names still fail to do these species justice after awet winter. The few annuals that flower after late sum-mer thundershowers become more numerous towardthe southeast, across the Colorado River and the Mexi-can border.

Animals of the Desert Scrub. Desert animals arepresented with a series of difficult challenges includ-ing extremes in temperatures, lack of reliable watersources, and limited food production during drought.Unusual adaptations allow a surprising variety of an-imals to survive and even thrive in these conditions.Many desert animals get their moisture from eatingplants or other animals and excrete very concen-trated waste, saving moisture. Larger animals andbirds can move to water sources, while others mustescape the heat and drought by burrowing or seekingother shelter. Ectothermic animals have an advan-tage in the desert because they gain much of theirheat from the environment, rather than by metabo-lism, which uses more energy. Many animals willpant to cool off after overheating. Here is a partialsummary of the busy animal world in a typical Cali-fornia desert scrub environment.

Ants, bees, beetles, butterflies, and moths are some ofthe pollinating insects that become more commonwhen their targeted flowers are in bloom, especiallyduring spring. Tent caterpillars live in colonies behindtheir webs, often feeding on desert plants in the rosefamily. Beetles and millipedes feed off decaying or-ganic debris at the base of many shrubs. Black stinkbeetles will often point their abdomens upward andemit a foul liquid when threatened. Crickets, katydids,

Desert Wash, Riparian, and Oasis Communities 169

and many kinds of spiders are also common. Scorpi-ons wait for their prey (usually other arthropods andoften other scorpions) at night, then sting and crush it.Tarantulas attack and eat prey that venture into theirwebbed burrows. The large, black tarantula hawk is awasp which seeks out and paralyzes the tarantula sothat its larvae may feed from the spider.

Reptiles usually eat insects and other animals, withexceptions such as California’s largest lizard, thechuckwalla, which is a vegetarian. This usually dullgray or black lizard is already plump but wrinkled andit can store water under its skin. When threatened, itmay lodge itself into rock cracks and inflate so that itcannot be pulled out. Numerous other lizard speciesare active in the desert scrub.

All snakes are carnivores. Rattlesnakes are pit vipers thatsense out their prey, stun them with powerful venom,and then follow them until they drop. They can swallowmammals larger than their heads. The Mojave rattle-snake has some of the most potent venom. Though Cali-fornia rattlesnake bites cause painful swelling and ill-ness, they very rarely are deadly to the careless humanswho have forced snakes to defend themselves. The bestadvice to relieve symptoms is to get the victim to thenearest hospital.

The lethargic desert tortoise can store up to one liter(quart) of water. It is now a threatened species par-tially due to those who have taken them for pets, runthem over with vehicles, or used them for target prac-tice. However, the large aggressive raven populationsthat have exploded in recent decades are primarily re-sponsible for the more than 90 percent decrease indesert tortoise populations, which occurred within 50years ending in the late twentieth century.

Various toads become active after desert rains.Couch’s spadefoot toad comes out of its burrow,mates, and lays its eggs in temporary ponds. Within amonth, the larvae grow into tadpoles, grow legs, thenleave the water just in time to burrow—as toads—toescape the drought with their stored water. They willemerge when the thunder and rain return.

Desert wood rats gather debris, including sections ofcholla, to make their nests. They rely on such plantsas prickly pear cactus for their moisture. Kangaroorats scrape and discard the salt off saltbrush leaves,which have high water content, before eating them.They can live their entire lives without drinkingwater; with very concentrated waste, they are one ofthe best water conservers in the desert. Protected intheir burrows by day from the desert heat, they eveneat their waste to gain the moisture back. Like kanga-

roo rats, pocket mice and ground squirrels often feedoff seeds from shrubs and make their burrows underprotective canopies of those same plants. Grasshop-per mice are deadly, aggressive predators. They eatinsects and attack scorpions by first biting off theirstingers. They even attack and eat other rodents. Batsuse their sonar to feed at night when temperaturesare lower.

Jackrabbits are the hares with giant ears that allowrapid heat loss. Cottontail rabbits have shorter ears;they live in burrows and become active at night insummer to escape the heat. Coyote occasionally feedon them after running them down, as they dart frombush to bush.

Desert Scrub Birds. Several birds, such as cactuswren, have learned to make nests in spiny chollas orother cactus for protection. Hummingbirds are impor-tant pollinators of specific tubular flowers. The phain-opepla is a dark bird with a large crest which oftenrests on the top of branches when it is not consumingseeds of the desert mistletoe. These seeds are distrib-uted to other plants in its droppings, disbursing themistletoe.

Many birds (including verdins, swallows, flycatchers,gnatcatchers, swifts, and wrens) feed off desert in-sects. Some of these are gleaners, and all of them gainmoisture from their food. Common raven populationsincreased more than 300 percent in parts of the Cali-fornia deserts during the 1900s and they pose a seri-ous threat to native species, including the desert tor-toise. Roadrunners rarely fly, but these cuckoos canrun and glide with their long tails up to 24 km (15miles) per hour. They will eat berries and insects, butthey may be more famous for their attacks on smallmammals, lizards, and even rattlesnakes.

This is just a sample of some of the activity among themany animals living in what unknowing visitors havelabeled a desert “wasteland.”

� DESERT WASH, RIPARIAN, ANDOASIS COMMUNITIES

Habitat and StructureLimited water is most responsible for restricting biomassand species diversity in California’s transmontanedeserts. Therefore, it is no surprise that ribbons of largerplants and lusher growth follow dry washes. Here, watermay only briefly flow, then disappear below the surfacebut still within reach of root systems. As expected, thegrowth may become dense thickets or even strips of

gallery forests where surface water is found most of theyear and where richer soils remain moist year-round.These conspicuous interruptions in the dry scrub repre-sent just a tiny fraction of California’s desert landscapes.They also represent vital watering holes and productionzones for site-specific plant and animal species and foranimals capable of commuting in from great distancesfrom around the region.

There is great diversity in these plant communities.Where surface water flows rarely over impermeablebedrock of desert washes, there may be only subtlechanges in the monotonous desert scrub, but wherethere is permanent surface water or thick sediment andabundant groundwater, there is an explosion of life andactivity. Abundant growth is rarely established in themiddle of braided channels that carry the most destruc-tive flash floods. However, these events are often re-sponsible for depositing rich sediment, dispersing seeds,and increasing species diversity from the wash channelto its outer banks. The common larger shrubs and smalltrees are often deeply rooted and deciduous.

Desert Wash Plants. Honey Mesquite (Prosopis glan-dulosa) is one of the most common of the tall shrubs orsmall trees to inhabit the desert wash. Joining theHoney Mesquite is a similar member of the numerouslegumes, Catclaw Acacia (Acacia greggii). Theselegumes grow long seed pods that were importantfood sources for Native Americans and are still vital tothe survival of so much wildlife. Roots of some youngplants have been known to grow up to 10 cm (4inches) per day until reaching soil moisture. Then, theplants can safely establish surface growth, sometimes

years later. Numerous sharp barbs growing on itsstems also earned catclaw its other name—wait-a-minute-bush.

Other common members of the pea family includethe Palo Verde (Cercidium floridum). It gets its “greenstick” name from the chlorophyll in the bark that re-mains after it drops leaves during severe drought.Smoke Trees (Psorothamnus spinosus) rarely haveleaves, but literally appear like ghostly gray puffs ofsmoke only along washes of California’s lower,southeastern deserts. Like all the species named sofar, the evergreen Ironwood (Olneya tesota) seedsrely on flash floods to tumble, scarify, and crack themto germinate. This further restricts them to desertwashes.

There are many willows common to these communi-ties, but Desert Willow (Chilopsis linearis) is oftenfound lining washes of the Mojave, even though it isnot a true willow. It does have long narrow leaves, butits pink flowers resemble snapdragons and its seedpods resemble beans.

Numerous desert wash shrubs may also be found inthe open desert, but many species, such as Arrow-weed (Pluchea sericea) are usually restricted to thesewetter sites. Arrow-weed stems were gathered by Cal-ifornia Indians for making baskets and arrows. Chu-parosa (Justica californica) is actually a tropical-likeshrub with long, red tubular flowers. Burrobush orCheesebush (Hymenoclea salsola) produces a rancidcheesy aroma when it is crushed between the fingers.Many other shrubs, such as Broom Baccharis orDesert Broom (Baccharis sarothroides) grow alongwith these plants. This nearly leafless plant withbroom-like stems may grow up to 4 m (13 feet) high inwetter habitats.

The open sediments and sands of these washes areoften splattered and sometimes covered with thespectacular colors of desert wildflowers in spring. Thesize and density of these ephemeral herbs often de-pends on temperatures and especially the amount andtiming of seasonal rainfall.

Plants of Desert Riparian and Oasis Communities.Diversity and biomass often increase where more reli-able water sources are available at or near the surface.Different species of willow (Salix spp.) become com-mon and may combine with sedges, rushes, and cat-tails to form thickets. Various other willow-like shrubsjoin arrow-weed, including the similar Mule-fat orSeep-willow (Baccharis glutinosa or salicifolia). Join-ing and similar to desert broom is a common indicatorof water, Squaw Waterweed, or simply Baccharis


Figure 5-17 California fan palms are only native to thestate’s southern desert oases. They often grow where waterseeps out of upstream faults and flows down throughcanyons. You might find them from Joshua Tree National Parkto Palm Springs and Anza-Borrego, but any palms you see onthe coastal side of the mountains were imported.

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Desert Wash, Riparian, and Oasis Communities 171

CALIFORNIA DESERTS’ ECOLOGIC ISLANDS AND SAND DUNES

Habitats and StructureTransmontane deserts, like cismontane California, containecologic islands. These are sometimes islands of plenty, suchas the oasis communities previously outlined. Often they areislands of even greater adversity, such as the alkali sinks withtheir halophytes or areas of poor soils, such as those weath-ered from limestone and dolomite, where specialized plantssuch as bristlecone pine grow. The formation of stark desertpavement, lacking surface soils, was a subject of Chapter 3 onCalifornia’s geology and geomorphology. Spineflower orSpiny Herb (Chorizanthe rigida) is a tiny, spiny buckwheatannual that turns into a prickly, dried protrusion up to a fewcms (inches) above the hot, stony surfaces. There are fewcompetitors in these dried infernos!

We end our journey through California’s plant communi-ties in its desert sand dunes. The formation of such great dunefields—from the Basin and Range’s Eureka, Death, Panamint,and Owens Valleys, through the Mojave to the Kelso Dunesand Devils Playground, to the Colorado Desert’s AlgodonesDunes—was a subject in Chapter 3. Though dune sand coversless than 5 percent of California’s deserts, that is still a lot ofland within such vast deserts of such a large state. Here, weexamine some of the life within California’s desert dunes.

It is fitting that these communities have so much—and somany plants—in common with the coastal dunes where webegan our journey in this chapter. To recognize how plantcommunities so geographically detached can be so similarhelps us to understand the connections between the many re-gions and diverse settings that make California such a fascinat-ing state. Like their counterparts along the coast, many desert

dune plants have fast-growing and extensive underground rhi-zomes which help anchor the plants and stabilize the dunes.Some are phreatophytes with deep tap roots that grow downto the water that first percolated through and was thentrapped below the sand. When their roots find moisture, thesenormally small shrubs may grow much larger on and near thedunes. Herbaceous ephemerals may grow quickly followingrare heavy rains, produce flowers, then seeds, and die backduring the intense drought certain to follow.

Plants. Some of the most noticeable species also growin other communities. They include creosote, salt-brush, indigo bush (Psorothamnus spp.), Mormon tea,mesquite, and desert willow in the Mojave and PaloVerde in the Colorado Desert. They are joined byperennial grasses which include endemics such as Eu-reka Dunegrass (Swallenia alexandrae), found only inInyo County, where its expanding underground rhi-zomes follow shifting sands.

Most of the wildflowers are low-growing, spring-flowering, herbaceous ephemerals. These includeDune or Evening Primrose (Oenothera spp.), with itslarge white flowers, which open in evening hours toattract moths, and Sand Verbena (Arbronia villosa),which grows rose to purple flowers on a vine. An-other vine-like plant is the Coyote Melon (Curcurbitaspp.), which grows gourds known as Calabazilla orBuffalo Gourd. The white Desert Lily (Hesperocallisundulata) grows a large, deeply buried, onion-likebulb also known as the Ajo. Desert sunflowers,

Figure 5-18 Plants hold on to shift-ing sands at Kelso Dunes. Their rootsanchor them and help stabilize thedunes. Months without rain and sear-ing summer heat make this a challeng-ing, dangerous habitat for any livingcreature. At night, the dunes comealive with prey and predators lookingfor dinner.

(Baccharis sergilloides). Joining honey mesquite is asimilar legume growing to tall shrubs or small trees andproducing twisted bean pods—Screwbean Mesquite(Prosopis pubescens).

Velvet or Arizona Ash (Fraxinus velutina) grow tosmall trees in riparian strips of desert mountains andinto the Sierra Nevada. The larger Fremont Cotton-wood (Populus fremontii) is a sure sign of moreprominent and permanent sources of water; theyeven combine in strips of forests along the few morepermanent water courses (such as the Mojave River)of California’s deserts, where seedlings thrive in de-posits of fresh, moist silt.

Introduced species, such as the previously notedTamarisk or Salt Cedar (Tamarix spp.), may becomeproblem invaders when they aggressively competewith natives for water. They were once planted aswind breaks, but one mature tamarisk can draw andtranspire nearly 50 liters (14 gallons) of water per day.Their extensive roots grow rapidly. Today, aggressivethickets of tamarisk seriously deplete desert watersources throughout southeastern California. Whentamarisks are removed, water returns, followed bynatural vegetation.

California Fan Palm (Washingtonia filifera) is Califor-nia’s only native palm tree. It grows naturally in ripar-ian and oasis communities from Twentynine Palmsand Joshua Tree National Park south into Baja Califor-nia. Some famous place names in California’sdeserts—including Thousand Palms, Palm Desert,and the Palm Canyons of Palm Springs and Anza Bor-rego Desert State Park—are identified by their impres-sive palm oases. These relic palms were stranded andisolated along and below desert springs—with desertspecies previously noted—thousands of years ago, asclimates became drier. They are usually found alongor downstream from faults where rocks have beencrushed, ground, and weakened, allowing ground-water seeps and natural springs to erupt. Over mil-lions of years, they have also been gradually draggedtoward the northwest from Mexico on the west side ofthe San Andreas Fault.

Growing the largest leaves of any California desertplant, they require perennial sources of water. Theseeds are distributed by birds, such as the Americanrobin, and other animals, such as the coyote. NativeAmericans used their fibers, ate their fruits, and alsodistributed their seeds. Like so many other Californiaplants, California fan palms benefit from fires that


CALIFORNIA DESERTS’ ECOLOGIC ISLANDS AND SAND DUNES(continued)

marigolds, dicoria, codenia, and spanish needles arejust some of the common names within the longerlist of wildflowers that may appear after rare rainfall.The Algodones Dunes alone contain six plants thatoccur nowhere else in the world. There are at leasteighty-five species endemic to all of California’sdeserts, making their contributions to the state’s di-verse and unique natural settings.

Animals. Numerous pollinating insects gather nectarfrom dune wildflowers. Beetle tracks and the tracks ofmany small mammals are common on the desertsands, sometimes with the coyote in pursuit. Most ofthe animals found in these communities are commonin other desert habitats and have been previouslynoted, but there are several animal species that areparticularly successful in the dunes.

Fringed-toed lizards live in wind-blown sand and arebuilt to dive so quickly into the sand, they are said to besand swimmers. Zebra-tailed lizards have side bandsand black zebra-like bars on the bottom of their tails.Their speed has been clocked up to 29 km (18 miles)per hour as they sprint on hind legs with their tails

curled behind. Various rattlesnakes are found aroundthe dunes. They usually don’t rattle unless they arethreatened by a larger animal. The sidewinder is an ex-ample of a rattler perfectly adapted to the sand. It hidesits body in the sand with only the head up, waiting for apotential dinner, usually an unfortunate rodent. Thesidewinder can accelerate to impressive speeds withits meandering or side-winding locomotion.

A hawk may soar near the dunes in search of its nextvictim among the activity below, while the vulture willwait for the desert to eliminate a weaker individual.The migrant birds and other species have left long be-fore the days of severe heat and drought, and on thosedays when the sand gets blistering hot, the animalswait in shelter, mostly below the sand. At dusk, thedesert again erupts in life. Birds such as poorwill andnighthawk hunt for insects well into the evening, andowls swoop down on unsuspecting prey. As the desertkit fox darts around the sand, it is certain that there willbe tiny tracks leading only away from more than onelittle mammal’s burrow. These are tracks of the latestvictims of nature’s grand cycle, victims that will neverreturn to those burrows.

Plants and Animals Introduced by Humans 173

clear the surface of competitors and allow seedlings tothrive. Along with other palms from around the world,they have been introduced especially into cismontanecentral and southern California, where they thrivewhen nurtured. The palm trees people often associatewith Los Angeles, Hollywood, and the southern Cali-fornia coast have all been introduced into a Mediter-ranean region where they do not belong.

Animals of Desert Wash, Riparian and Oasis Com-munities. Many of the previously noted desert ani-mals live within or frequently visit these water holes.They will not be repeated here.

Nearly half of California fan palms have tiny holescaused when giant palm-boring beetles lay their eggs.For years afterward, the larvae drill tunnels in thepalm wood. Females of the southern California car-penter bee use the beetles’ exit holes to raise theiryoung.

Mule deer visit riparian and oases communities forwater and fresh green meals. Coyotes come for thewater and the abundant smaller prey living within theprotection of the dense vegetation. Desert bighornsheep come to eat leaves and shrubs and must drinkregularly.

At least eleven different pupfish and five killfish wereisolated in water bodies after the end of the lastGlacial Period, when transmontane California’s inte-rior drainages began to dry and disconnect. These tinyspecies of fish have actually adapted to different tem-perature, chemistry, and other conditions unique toeach of the remaining ponds.

Black-chinned sparrows, Gambel’s quail, gnatcatch-ers, and ladder-backed woodpeckers may remain inCalifornia desert oases. Other sparrows visit for thewinter, and warblers and others visit in spring, whilegrosbeaks, hooded orioles, and flycatchers fly in dur-ing summer to feast on oasis plants and insects.

If not permanent homes, these islands of food andwater serve as crossroads, rest stops, and places ofcongregation for numerous animals.

� PLANTS AND ANIMALSINTRODUCED BY HUMANS

Throughout this chapter, we have reviewed some of theintroduced species that have invaded, competed,and thrived in California’s natural and not-so-naturalplant communities. As the list of intruders grows, theyoften place more stress on organisms already challenged.

These invaders become common and successful in dis-turbed sites, particularly where the human imprint ismore pronounced.

Considerable attention has already been given tonon-native invaders that have been particularly aggressiveand successful in the state’s grasslands. Mustards, thistles,and a mint called horehound are examples. Perhaps themost famous of all weeds is the notorious tumbleweed,another species that earned considerable attention in aprevious section.

Of course, people have also purposely introducedand nurtured plants and animals that, for various rea-sons, they perceive as more attractive or useful than Cal-ifornia native species. Even where invading beach anddune grasses haven’t taken over our beach dunes, iceplant and other ground cover have often been purposelyintroduced to stabilize dunes. The saguaro cactus hasbeen transported west of the Colorado River into theCoachella Valley and beyond. California’s native fanpalm now decorates landscapes throughout southernand central California, far beyond the confines of its orig-inal desert oases. With a little water, other palms fromaround the world are thriving, but only the fan palm isnative to California.

We will end this chapter by listing a few of the morecommon non-native species that pose problems as theysqueeze out the natives in California wildlands. Theyrange from edible figs to various European brooms, fromgiant reeds to pampas grass (Cortaderia species). Fen-nel, with its strong licorice smell, is another example ofan aggressive non-native. Biologists estimate that up to20 percent of the plant cover in the state’s open landsconsists of introduced invaders. Even California farmersare battling opportunistic weeds that cut into agriculturalproduction and profit.

The ubiquitous eucalyptus is a good example ofwhat can happen when a non-native species is intro-duced for what seems to be a good reason. When this in-vader from Australia failed to provide valuable wood to agrowing California, it was used for wind breaks andshade. It thrived in the Mediterranean climate, but it is aragged tree that can, without warning, drop huge limbs.In groves, eucalyptus represents a serious fire hazard.Residents of the Oakland hills learned this fire lesson thehard way in the 1990s.

After burros used as pack animals broke loose fromearly California prospectors, they quickly multiplied andpopulated California deserts. Burros had overgrazed anddamaged thousands of square miles of California desertscrub before government agencies from the Bureau ofLand Management to Death Valley National Monument(now National Park) advertised their adopt-a-burro pro-gram during the 1980s. Many of the big-eared invaderswere successfully rounded up and given homes by burrolovers, allowing some desert scrub to recover forbighorn and other natives and grazers.

Wild horses have created similar problems by over-populating and overgrazing rangelands. When non-nativeanimals are introduced, it may be reasonable to considerany number of them as enough to overpopulate our wild-lands. These are only examples of some of the dilemmaspresented to those who manage our rangelands, wild-lands, and wildlife each year.

The list of intruders goes on and is especially evi-dent in or near California’s waterscapes. They includecrayfish consuming our California newts, habitat de-struction and non-natives eating away at numerous na-tive fish species, European green crabs munching theirway along the coast, and Chinese mitten crabs burrow-ing in levees and clogging pipes in the Delta. Non-nativefrog and turtle species were considered in more detailedsections of this chapter.

One of the most notable controversies erupted afterthe aggressive northern pike was somehow introducedinto Lake Davis in the northeastern Sierra Nevada in1994. State wildlife officials poisoned the lake in 1997to kill the pike before the fish could spread to threatenthe state’s aquatic industry. All other fish and insects inthe lake—including its famous trout—were also de-stroyed by the poison; nearby Portola lost its watersupply. The chemicals unexpectedly lingered for morethan 9 months, well into the summer, resulting inpainful losses to local businesses. Still, the northernpike rebounded. By 2004, officials had spent morethan $14 million using nets, explosions, electric shock,and chemicals, but the California Department of Fishand Game still worried that it would spread to neigh-boring waterways.

Many of the scores of plants and animals introducedinto the state by commercial agriculture are examined inChapter 9 on primary industries. Accompanying the newplants and animals are a host of introduced pests, weeds,and diseases that threaten the state’s agricultural produc-

tion each year. These have also earned considerable at-tention in Chapter 9.

� HUMANS ENCROACH ONANIMAL HABITATS

Throughout this chapter, we have examined scores ofCalifornia’s plant and animal species that are threat-ened, more seriously endangered, or even extinct.They range from some of the tiniest plants and insects tothe long-extinct California grizzly bear. The introductionof foreign competitors and predators, encroaching de-velopments, and other human activities are challengingthe very survival of countless native species across thestate. Debates about how to save these species involvewhich habitats to preserve and which developments andother human activities to curtail. Issues repeatedly fuel-ing and complicating these debates involve private prop-erty rights and short-term economic profits.

Finally, we will focus on two more species that havenot yet received the attention they deserve.

Thousands of bald eagles once soared free over Cal-ifornia’s coast and offshore islands. Their nesting num-bers dropped to about twenty in the 1960s due to DDT,habitat destruction, and human encroachments. Extinc-tion was a real possibility. Successful efforts by agenciessuch as the U.S. Fish and Wildlife Service and organiza-tions such as the Predatory Bird Research Group at UCSanta Cruz (with help from legislation such as the 1972Endangered Species Act) brought bald eagle nestingnumbers to over 100 during the 1990s.

By the twenty-first century, a growing number ofbald eagles were building their enormous nests near Cal-ifornia’s inland reservoirs, where stocked trout and otherfish represent year-round food supplies. Up to eighteeneagles have been observed in their winter migrations to


Fire Ants and Killer Bees Threaten

threatening agriculture, including the state’s nut and fruittrees.

Africanized “killer” bees arrived in southern California bythe late 1990s. By 2005, they had colonized southern Califor-nia and into the San Joaquin Valley. The similarity to the fireant problem is striking. They first made their way north fromwarmer Mexican climates. Once established, they becomehyper-defensive and hyper-aggressive. If disturbed or threat-ened, Africanized bees may launch aggressive attacks, inflict-ing hundreds of painful stings on their victims. Some of the at-tacks on humans and other animals have been fatal. Theyrepresent yet another example of how introduced species canbe more than just a nuisance to Californians.

Red imported fire ants from South America first invaded thesouthern United States during the 1900s. By the twenty-firstcentury, they were established in many of the California val-leys that do not experience long periods of below-freezingtemperatures. From the Central Valley south, they werebuilding mounds the size of basketballs as they crowded outestablished ant colonies and aggressively attacked any in-vaders. When disturbed, these red ants launch massive at-tacks that include painful stings laced with venom. Theyforced some families to abandon their backyards. As officialssearch for an efficient way to eradicate these pests, fire antsare expected to increase their range and become a greaterproblem in California well into this century. They are also

Additional Key Terms and Topics 175

� SOME KEY TERMS AND TOPICS �

alpinearctic-alpinebighorn sheepbristlecone pinecactus scrubCalifornia’s Kansaschaparralcismontane communitiesclosed-cone forestcoastal coniferous forestcoastal sage scrubcoastal strandcreosote bushdesert biomedesert scrub communities

desert washDouglas firfire adaptationsgrasslandindigenousJoshua treeslimiting factorsmeadowMediterranean scrubmixed evergreen forestmontane coniferous forestnativesoak woodlandoasis communitiespiñon-juniper woodland

pioneer plantsred fir/lodgepole pineredwoodripariansand dunesscrub biomesequoiasubalpinetemperate coniferous foresttemperate deciduous foresttransmontane desertstundra biomevegetation structureyellow pines

Lake Cachuma. Nesting pairs were observed at San Anto-nio and Nacimiento Reservoirs near the Monterey/SanLuis Obispo County border and at Skinner Reservoir inRiverside County. Officials upgraded the bald eagle’s sta-tus from endangered to threatened in the 1990s and, bythe end of the century, were urged to remove it from thelistings under the Endangered Species Act. These aresubstantial improvements since the 1960s, when bald ea-gles had entirely disappeared from southern California.

The California condor’s story is a similar one, exceptthat it edged so close to extinction that there were finallyno condors in the wild. The state’s most famous vulturestypically grow to about 20 pounds with a wing span of 3m(9 feet). But, California’s largest birds became the most en-dangered. Costly efforts to save them included raising theremaining few condors in captivity, while teaching themto fear humans and survive in the wild. These painstakingefforts involved Ventura’s Condor Recovery Program, theU.S. Fish and Wildlife Service, local zoos, and other orga-nizations, such as the Audubon Society.

As their numbers grew in captivity (from less than 30in the 1980s), condors were gradually freed. As ex-pected, some never survived due to power lines, acci-dental poisoning, illegal shootings, and other incidents.By 2005, condor chicks had again hatched in the wildand for the first time in more than 20 years, one success-fully flew out of its nest. By then, there were about 200condors in California and a few other locations; abouthalf were in the wild.

Notice the connections that must be made to under-stand and solve these problems that threaten and endan-ger our native plants and animals. Natural disasters,changes in weather and climate, water diversion andstorage projects, increasing human populations, eco-nomic activities, cultural values, technologies, and grow-ing urban areas all play important roles; each haveearned entire chapters in this book. An understanding ofthe varied processes, cycles, and systems that are shap-ing California landscapes and how they are connectedbecomes extremely valuable.

beachbiomassbiomeclimax communitiescoastal sand dunesdrought-deciduousecologic islands

ecosystemendangered/threatened speciesfood pyramidhabitatintroduced specieslife zoneslittoral strip

pyrophytesclerophyllspecies diversitysuccessiontree linevegetation zonesxeric

� ADDITIONAL KEY TERMS AND TOPICS �

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