BiomesBiomes

BiomeBiome

• a large group of ecosystems that share the same type of climax community

2 Types of Biomes2 Types of Biomes

Terrestrial (land) Biomes Aquatic (water) Biomes

marine (salt water)freshwater biomes

6 Major Terrestrial (Land) Biomes6 Major Terrestrial (Land) Biomes

• terrestrial biomes are defined by their latitude, altitude, and precipitation

Terrestrial BiomesTerrestrial Biomes

• tundra

• taiga

• dessert

• grasslands

• temperate forest

• tropical rain forest

TundraTundra• treeless area around the poles

• temperatures rise above freezing only for very short periods of time, about 12 cm precipitation annually

Tundra

• soil is lacking in nutrients; topsoil is thin -little decay occurs

• soil supports only shallow-rooted grasses and small plants

• short growing season-limiting factor for life

• contains permafrost - layer of permanently frozen ground

•called northern conifer forest•climate is harsh - long, severe winters, short, mild summers, 35-40 cm precipitation annually•permafrost is usually absent•found in Canada, Northern Europe, Asia

Taiga

TaigaTaiga

Flora/Fauna:

• lichens, mosses, grasses, dwarf shrubs, cushion plants, mosquitoes, other biting insects, lemming, weasels, arctic foxes, snowshoe hares, snowy owls, hawks, musk-oxen, caribou, reindeer

Taiga

•topsoil is acidic and poor in minerals

Example Organisms: mixed pine, fir, hemlock, & spruce trees, more large species of animals- caribou, moose, lynx

•Driest of the biomes, less than 25 cm of precipitation annually•Located south of the taiga•Atacama Desert in Chile – world’s driest place

Desert

Desert

•desert plants sometimes have spines, thorns, or poisons that act to discourage herbivores•example organisms - shrub, mesquite trees, cacti, kangaroo rat, pronghorn antelopes, foxes, coyotes, hawks, owls, roadrunners, snakes, lizards, scorpions

•an arid region with sparse to almost nonexistent plant life

GrasslandGrassland

• soils have considerable humus content•usually experience a dry season where insufficient water exists to support forests

–example organisms - more than 100 different species per acre, large herds of grazing animals, bison, buffalo, wolves, coyotes, prairie dogs, foxes, ferrets, birds, insects, reptiles, tortoises, lizards, snakes

•receives between 25 and 75 cm of precipitation annually

Grassland

•large communities covered with grasses and similar small plants•known as prairies (U.S., Canada, & Australia), steppes (Russia), savanna (Africa), pampas (Argentina) •called the breadbaskets of the world-ideal for growing grains (oats, rye, wheat)

•occupies more area than any other terrestrial biome

Temperate ForestTemperate Forest

– soil consists of top layer rich in humus and a deeper layer of clay

– example organisms - squirrels, mice, rabbits, birds, black bears, deer, salamanders, opossums

•precipitation ranges from 70-150 cm annually•deciduous forests - dominated by broad-leaved hardwood trees that lose their foliage annually (deciduous)

Temperate Forest

Tropical Rain ForestTropical Rain Forest– most biologically diverse of the terrestrial biomes,

located in the equatorial regions around the world– uniformly warm (25oC) , wet weather dominated

by lush plant growth, annual rainfall is at least 200cm up to 400 cm, which much of is retained and recycled by the heavy canopy of leaves

• most organisms live in the trees• more species of reptiles, amphibians, and birds are found here than any other terrestrial biome• 3 million species of insects in the tropical rain forest, butterflies, gorillas, cougars

Nutrients from decay must be absorbed quickly. Why?

Tropical Rain Forest

Due the large amount of rain

Precipitation AmountsPrecipitation Amounts

1240 25

75 70

150

200

400

0

50

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150

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250

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cip

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TundraTaigaDessertgrasslandstemperate foresttemperatrate forest IItraopical rain foresttropical rain forest II

1 cm = 0.4 inches

Marine BiomesMarine Biomes• oceans contain the largest amount of

biomass (living material) of any biome on Earth

• most of this biomass is plankton - microscopic organisms that float in the layers of the photic zone

Water ZonesWater Zones

•photic zone - more shallow, sunlit zone

•aphotic zone - deeper water that never receives sunlight

Mixed Mixed WatersWaters

•all waters flow to a sea/oceanall waters flow to a sea/ocean

•estuaryestuary – coastal body of – coastal body of water partially surrounded by water partially surrounded by land where saltwater and land where saltwater and freshwater mixfreshwater mix

TidesTides

•caused by the gravitational caused by the gravitational pull of the sun and moon – pull of the sun and moon – twice a daytwice a day

•intertidal zoneintertidal zone – area – area between the high and low between the high and low tide linestide lines

Photic Photic ZoneZone

•rainfall washes nutrients from land rainfall washes nutrients from land into the watersinto the waters

•high in nutrients and abundant in high in nutrients and abundant in life life

•planktonplankton – small organisms that – small organisms that live in waters of the photic zone – live in waters of the photic zone – base of all aquatic food chainsbase of all aquatic food chains

Aphotic Aphotic ZoneZone

•intense pressureintense pressure

•no lightno light

•animals are adapted for animals are adapted for darkness and scarcity of fooddarkness and scarcity of food

Freshwater Freshwater BiomeBiome ponds, rivers, and lakesponds, rivers, and lakes temperature varies with depth – temperature varies with depth –

abiotic factor that limits the kind abiotic factor that limits the kind of organisms that can survive in a of organisms that can survive in a deep lakedeep lake

light also is a limiting abiotic light also is a limiting abiotic factorfactor