Lecture 10Lecture 10B I O M E SB I O M E S

HRhHRh

BiomesBiomes

Biomes are regions of the world with Biomes are regions of the world with similar climate , animals and plants similar climate , animals and plants such as desert, tropical rain forest, such as desert, tropical rain forest, freshwater biomes, etcfreshwater biomes, etc

Knowledge of basic characteristics of Knowledge of basic characteristics of the world’s major biomes and the world’s major biomes and features of life within each is features of life within each is important for planning, dealing with important for planning, dealing with environmental issues, and environmental issues, and determining beneficial introduction of determining beneficial introduction of new species new species

The rule of climatic similarityThe rule of climatic similarity

Why do different types of desert, grassland, forest exist?Why do different types of desert, grassland, forest exist? The general answer to these questions is differences in The general answer to these questions is differences in

climate, caused mostly by differences in average temperature climate, caused mostly by differences in average temperature and precipitation caused by global air circulation and precipitation caused by global air circulation

Different climates promote different community of organismsDifferent climates promote different community of organisms Similar environments lead to the evolution of organisms similar Similar environments lead to the evolution of organisms similar

in form and function and to similar ecosystemsin form and function and to similar ecosystems This is known as the rule of climatic similarity and leads to the This is known as the rule of climatic similarity and leads to the

concept of the biomesconcept of the biomes There is a strong relationship between climate and life There is a strong relationship between climate and life The rule of climatic similarity is important in environmental The rule of climatic similarity is important in environmental

science because by kscience because by knowing the climate, we can predict a nowing the climate, we can predict a great deal about what kinds of life we will find in an area and great deal about what kinds of life we will find in an area and what kinds could survive there if introducedwhat kinds could survive there if introduced

The rule of climatic similarityThe rule of climatic similarity

Convergent evolutionConvergent evolution The process by which The process by which

species evolve in different species evolve in different places and/or at different places and/or at different times, having different times, having different genetic heritages, develop genetic heritages, develop similar external forms and similar external forms and structures as a structures as a result of result of adaptation to similar adaptation to similar environmentenvironment

The rule of climatic similarityThe rule of climatic similarity

Although geographically Although geographically isolatedisolated for for 180 million years180 million years, certain , certain plants of the American and plants of the American and African deserts may look alike in African deserts may look alike in spite of not being closely related spite of not being closely related and belonging to different and belonging to different biological familiesbiological families

The ancestral differences The ancestral differences between these look-alike plants between these look-alike plants can be found in their flowers, can be found in their flowers, fruits, and seeds (most fruits, and seeds (most conservative organs) & provide conservative organs) & provide best clues as to the genetic best clues as to the genetic history of a specieshistory of a species

Major biomes Major biomes

Tundra, Boreal Forests or Taiga, Temperate Forests, Tundra, Boreal Forests or Taiga, Temperate Forests,

temperate Rain Forests, Temperate Woodlands, Temperate temperate Rain Forests, Temperate Woodlands, Temperate

Shrub lands, Temperate Grasslands, tropical Rain Forests, Shrub lands, Temperate Grasslands, tropical Rain Forests,

Tropical Seasonal Forests and Savannas, Deserts, Wetlands, Tropical Seasonal Forests and Savannas, Deserts, Wetlands,

Freshwaters, Intertidal, Open Ocean, etc.Freshwaters, Intertidal, Open Ocean, etc.

Tundra BiomesTundra Biomes

TundraTundra— treeless plains occur under harsh climates of — treeless plains occur under harsh climates of

low rainfall and low average temperatureslow rainfall and low average temperatures Vegetation includes grasses & their relatives, mosses, Vegetation includes grasses & their relatives, mosses,

lichens, flowering dwarf shrubs, mat-forming plants, etclichens, flowering dwarf shrubs, mat-forming plants, etc

Tundra in autumn, AlaskaTundra in autumn, Alaska

ArcticArctic, occurs at high latitudes, occurs at high latitudes Important large mammals as well Important large mammals as well

as important small mammals, as important small mammals, birds, and insects are foundbirds, and insects are found

Covers the large territories Covers the large territories required for population of large required for population of large mammalsmammals

AlpineAlpine, occurs at high , occurs at high elevationselevationsAlpineAlpine—comparatively small, —comparatively small, isolated areasisolated areas• Vegetation is similarVegetation is similar• Dominant animals are Dominant animals are different— rodents and different— rodents and insectsinsects

Tundra BiomesTundra Biomes

Parts of tundra have Parts of tundra have permafrostpermafrost, extremely fragile , extremely fragile ecologicallyecologically

When disturbed by such activities as the development of When disturbed by such activities as the development of roads, may be permanently changedroads, may be permanently changed

Long-lasting damage to arctic tundra has been done by oilLong-lasting damage to arctic tundra has been done by oil

& natural gas exploration, and military use& natural gas exploration, and military use

Arctic tundra in winter and alpine in summerArctic tundra in winter and alpine in summer

Boreal forest BiomesBoreal forest Biomes

Taiga: Evergreen Forest of the NorthTaiga: Evergreen Forest of the North Taiga, or Boreal forest biome includes forests of high Taiga, or Boreal forest biome includes forests of high

latitudes and high altitudes, dominated by conifers, spruces, latitudes and high altitudes, dominated by conifers, spruces,

firs, larches, and pinesfirs, larches, and pines Characterized by dense stands of relatively small trees, Characterized by dense stands of relatively small trees,

typically under 30 m, form dense shade and make walking typically under 30 m, form dense shade and make walking

difficultdifficult

Boreal forest BiomesBoreal forest Biomes

Economically most important biomes as they are the sources of Economically most important biomes as they are the sources of much lumber and paper pulpmuch lumber and paper pulp

The dominant animals include a few large mammals (moose, The dominant animals include a few large mammals (moose, deer, wolves, bears), small rodents (squirrels, rabbits), small deer, wolves, bears), small rodents (squirrels, rabbits), small carnivores (foxes), many insects, & migratory birds, owls, eaglescarnivores (foxes), many insects, & migratory birds, owls, eagles

DisturbancesDisturbances—particularly fires, storms, and outbreaks of —particularly fires, storms, and outbreaks of insects are common insects are common

Tropical Rain Forest BiomesTropical Rain Forest Biomes

Tropical Rain ForestsTropical Rain Forests occur where the average temperature is high occur where the average temperature is high & constant throughout the year and precipitation occurs almost daily& constant throughout the year and precipitation occurs almost daily

Species diversity is high, with hundreds of species of trees within a Species diversity is high, with hundreds of species of trees within a few kmfew km22

Many species of animals occur, mammals tend to live in trees, Many species of animals occur, mammals tend to live in trees,

some are ground dwellerssome are ground dwellers Insects and other invertebrates are abundant & show high diversityInsects and other invertebrates are abundant & show high diversity Trees of tropical rain forests are typically evergreen flowering plantsTrees of tropical rain forests are typically evergreen flowering plants Typically, some trees are very tall (Typically, some trees are very tall (50 m50 m), some remain relatively ), some remain relatively

small (small (3m3m)) Others, like bromeliads & some ferns, grow on treesOthers, like bromeliads & some ferns, grow on trees DisturbancesDisturbances Human population growth and industrial expansionHuman population growth and industrial expansion

Amazon RainforestRainforest vegetation on the Caribbean island of Dominica

Desert BiomesDesert Biomes Found in both temperate (cold Found in both temperate (cold

desert) & subtropical or desert) & subtropical or tropical regions (warm desert) tropical regions (warm desert) where the rainfall is less than where the rainfall is less than 50 cm/yr50 cm/yr

Although most deserts occur Although most deserts occur at low latitudes, deserts occur at low latitudes, deserts occur in the basin and range area of in the basin and range area of Utah, Nevada, & western AsiaUtah, Nevada, & western Asia

Most deserts have a Most deserts have a specialized vegetation, specialized vegetation, specialized vertebrates and specialized vertebrates and invertebratesinvertebrates

Plants tend to have reduced Plants tend to have reduced leaves or no leaves, an leaves or no leaves, an adaptation that conserves adaptation that conserves waterwater

Red desert of Australia

Desert BiomesDesert Biomes Dominant animals of warm deserts Dominant animals of warm deserts

are non-mammalian vertebrates are non-mammalian vertebrates (snakes, reptiles)(snakes, reptiles)

Mammals are usually small, like Mammals are usually small, like kangaroo mice of North American kangaroo mice of North American deserts (cold deserts)deserts (cold deserts)

Disturbances are common in the form Disturbances are common in the form of occasional fires,of occasional fires, cold weather, and cold weather, and sudden, infrequent, & intense rains sudden, infrequent, & intense rains that cause floodingthat cause flooding

Off-road vehicle use damage desert Off-road vehicle use damage desert vegetationvegetation

Increased groundwater consumption Increased groundwater consumption by many desert cities has caused by many desert cities has caused groundwater levels to dropgroundwater levels to drop

Cold desert biome Cold desert animal

Fresh Water BiomesFresh Water Biomes

Fresh WatersFresh Waters are critical for our are critical for our water supply for homes, industry, water supply for homes, industry, & agriculture and play important& agriculture and play important ecological rolesecological roles

Major recreational resourcesMajor recreational resources Dominant plants are floating algae Dominant plants are floating algae

((phytoplanktonphytoplankton), water lilies in ), water lilies in shallow areasshallow areas

Open waters have many small Open waters have many small invertebrate animals— invertebrate animals—

zooplanktonzooplankton—both herbivores—both herbivores

& carnivores& carnivores

Freshwater angelfish

Fresh Water BiomesFresh Water Biomes

Economically important for drinking, energy, fish, bird life, Economically important for drinking, energy, fish, bird life, recreation & transportationrecreation & transportation

EstuariesEstuaries– rich in nutrients support an abundance of fish, – rich in nutrients support an abundance of fish, breeding sites for fishbreeding sites for fish

Human activitiesHuman activities cause adverse impact including pollution cause adverse impact including pollution Pollution alters the physical environment and changes the Pollution alters the physical environment and changes the biotic component downstreambiotic component downstream Alters aquatic ecosystemsAlters aquatic ecosystems

Open Ocean BiomeOpen Ocean Biome

Open Ocean biomeOpen Ocean biome includes open includes open waters ofwaters of much of the oceansmuch of the oceans

Vast areas low in nitrogen & Vast areas low in nitrogen & phosphorus phosphorus — — chemical desertchemical desertss with with low productivity and low diversity of low productivity and low diversity of algaealgae

Many species of large animals Many species of large animals

occur at low density occur at low density DisturbancesDisturbances Off-shore mining & oil drilling cause Off-shore mining & oil drilling cause

pollutionpollution Millions of ships dump oily ballast & Millions of ships dump oily ballast &

other wastes overboardother wastes overboard

End of SlidesEnd of SlidesThank YouThank You