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1. Lecture 10Lecture 10
B I O M E SB I O M E S
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2. BiomesBiomes
Biomes are regions of the world withBiomes are regions of the world with
similar climate , animals and plantssimilar 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 ofKnowledge of basic characteristics of
the world’s major biomes andthe world’s major biomes and
features of life within each isfeatures of life within each is
important for planning, dealing withimportant for planning, dealing with
environmental issues, andenvironmental issues, and
determining beneficial introduction ofdetermining beneficial introduction of
new speciesnew species

3. 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 inThe general answer to these questions is differences in
climate, caused mostly by differences in average temperatureclimate, caused mostly by differences in average temperature
and precipitation caused by global air circulationand 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 similarSimilar 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 theThis 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 lifeThere is a strong relationship between climate and life
 The rule of climatic similarity is important in environmentalThe rule of climatic similarity is important in environmental
science because by kscience because by knowing the climate, we can predict anowing the climate, we can predict a
great deal about what kinds of life we will find in an area andgreat 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

4. The rule of climatic similarityThe rule of climatic similarity
 Convergent evolutionConvergent evolution
 The process by whichThe process by which
species evolve in differentspecies evolve in different
places and/or at differentplaces and/or at different
times, having differenttimes, having different
genetic heritages, developgenetic heritages, develop
similar external forms andsimilar external forms and
structures as astructures as a result ofresult of
adaptation to similaradaptation to similar
environmentenvironment

5. The rule of climatic similarityThe rule of climatic similarity
 Although geographicallyAlthough geographically
isolatedisolated forfor 180 million years180 million years,,
certain plants of the Americancertain plants of the American
and African deserts may lookand African deserts may look
alike in spite of not beingalike in spite of not being
closely related and belonging toclosely related and belonging to
different biological familiesdifferent biological families
 The ancestral differencesThe ancestral differences
between these look-alike plantsbetween these look-alike plants
can be found in their flowers,can be found in their flowers,
fruits, and seeds (mostfruits, and seeds (most
conservative organs) & provideconservative organs) & provide
best clues as to the geneticbest clues as to the genetic
history of a specieshistory of a species

6. Major biomesMajor biomes
 Tundra, Boreal Forests or Taiga, Temperate Forests,Tundra, Boreal Forests or Taiga, Temperate Forests,
temperate Rain Forests, Temperate Woodlands, Temperatetemperate 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.

7. 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

8.  ArcticArctic, occurs at high latitudes, occurs at high latitudes
 Important large mammals as wellImportant large mammals as well
as important small mammals,as important small mammals,
birds, and insects are foundbirds, and insects are found
 Covers the large territoriesCovers the large territories
required for population of largerequired for population of large
mammalsmammals
AlpineAlpine, occurs at high, occurs at high
elevationselevations
AlpineAlpine—comparatively small,—comparatively small,
isolated areasisolated areas
• Vegetation is similarVegetation is similar
• Dominant animals areDominant animals are
different— rodents anddifferent— rodents and
insectsinsects

9. Tundra BiomesTundra Biomes
 Parts of tundra haveParts of tundra have permafrostpermafrost, extremely fragile, extremely fragile
ecologicallyecologically
 When disturbed by such activities as the development ofWhen 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

10. Boreal forest BiomesBoreal forest Biomes
 Taiga: Evergreen Forest of the NorthTaiga: Evergreen Forest of the North
 Taiga, or Boreal forest biome includes forests of highTaiga, 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 walkingtypically under 30 m, form dense shade and make walking
difficultdifficult

11. Boreal forest BiomesBoreal forest Biomes
 Economically most important biomes as they are the sources ofEconomically 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), smalldeer, 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 commoninsects are common

12. Tropical Rain Forest BiomesTropical Rain Forest Biomes
 Tropical Rain ForestsTropical Rain Forests occur where the average temperature isoccur where the average temperature is
high & constant throughout the year and precipitation occurs almosthigh & constant throughout the year and precipitation occurs almost
dailydaily
 Species diversity is high, with hundreds of species of trees within aSpecies 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

13. Amazon Rainforest
Rainforest vegetation on the
Caribbean island of Dominica

14. Desert BiomesDesert Biomes
 Found in both temperate (coldFound in both temperate (cold
desert) & subtropical ordesert) & subtropical or
tropical regions (warm desert)tropical regions (warm desert)
where the rainfall is less thanwhere the rainfall is less than
50 cm/yr50 cm/yr
 Although most deserts occurAlthough most deserts occur
at low latitudes, deserts occurat low latitudes, deserts occur
in the basin and range area ofin the basin and range area of
Utah, Nevada, & western AsiaUtah, Nevada, & western Asia
 Most deserts have aMost deserts have a
specialized vegetation,specialized vegetation,
specialized vertebrates andspecialized vertebrates and
invertebratesinvertebrates
 Plants tend to have reducedPlants tend to have reduced
leaves or no leaves, anleaves or no leaves, an
adaptation that conservesadaptation that conserves
waterwater
Red desert of Australia

15. Desert BiomesDesert Biomes
 Dominant animals of warm desertsDominant animals of warm deserts
are non-mammalian vertebratesare non-mammalian vertebrates
(snakes, reptiles)(snakes, reptiles)
 Mammals are usually small, likeMammals are usually small, like
kangaroo mice of North Americankangaroo mice of North American
deserts (cold deserts)deserts (cold deserts)
 Disturbances are common in the formDisturbances are common in the form
of occasional fires,of occasional fires, cold weather, andcold weather, and
sudden, infrequent, & intense rainssudden, infrequent, & intense rains
that cause floodingthat cause flooding
 Off-road vehicle use damage desertOff-road vehicle use damage desert
vegetationvegetation
 Increased groundwater consumptionIncreased groundwater consumption
by many desert cities has causedby many desert cities has caused
groundwater levels to dropgroundwater levels to drop
Cold desert biome Cold desert animal

16. Fresh Water BiomesFresh Water Biomes
Fresh WatersFresh Waters are critical for ourare 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 algaeDominant plants are floating algae
((phytoplanktonphytoplankton), water lilies in), water lilies in
shallow areasshallow areas
 Open waters have many smallOpen waters have many small
invertebrate animals—invertebrate animals—
zooplanktonzooplankton—both herbivores—both herbivores
& carnivores& carnivores
Freshwater angelfish

17. 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 pollutioncause adverse impact including pollution
 Pollution alters the physical environment and changes thePollution alters the physical environment and changes the
biotic component downstreambiotic component downstream
 Alters aquatic ecosystemsAlters aquatic ecosystems

18. Open Ocean BiomeOpen Ocean Biome
 Open Ocean biomeOpen Ocean biome includes openincludes open
waters ofwaters of much of the oceansmuch of the oceans
 Vast areas low in nitrogen &Vast areas low in nitrogen &
phosphorusphosphorus —— chemical desertchemical desertss withwith
low productivity and low diversity oflow productivity and low diversity of
algaealgae
 Many species of large animalsMany species of large animals
occur at low densityoccur at low density
 DisturbancesDisturbances
 Off-shore mining & oil drilling causeOff-shore mining & oil drilling cause
pollutionpollution
 Millions of ships dump oily ballast &Millions of ships dump oily ballast &
other wastes overboardother wastes overboard

19. End of SlidesEnd of Slides
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