12/19/2014
Biomes
• Biome
– Group of ecosystems with similar abiotic and
biotic conditions
– Spread throughout Earth
– Classified by climate and plant/animal life
Biomes
Hot
•
•
•
•
Desert (most)
Tropical Rainforest
Tropical Dry Forest
Chapparal
Intermediate
Savanna
Temperate Deciduous Forest
Temperate Rainforest
Temperate Grasslands
Cold
• Taiga
• Tundra
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•
•
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Biomes
• Temperate Deciduous Forest
– Evenly spread precipitation
• 0.75 – 1.25 m
– Temperature extremes
• 95 °F in the summer, < 0 °F winter
– Plants grow in layers
• The canopy contains tall trees like maple, oak, and
birch
• The understory contains smaller trees, shrubs, and
ferns
Biomes
Wet
• Tropical Rainforest
• Temperate Rainforest
Intermediate
• Tropical Dry Forest
• Temperate Deciduous Forest
• Taiga
• Savanna
Dry
• Temperate Grasslands
• Chapparal
• Tundra
• Desert
Biomes
• Temperate Deciduous Forest
– Trees shed leaves in fall
– Seeds are dormant till spring
– Birds migrate
– Many animals hibernate
– Year-round animals store food for winter
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Temperate Deciduous Forests
• Mutualism
– Chipmunk eats pecans,
spreading tree’s seeds
• Competition
– Blackberry grows into
grass space
• Commensalism
– Squirrel lives in oak tree
Biomes
• Temperate Grasslands (Prairies)
– Grasses grow from roots
• Continue to grow after grazing
– Winds don’t harm low plants/grass
– Animals burrow
• Nowhere to hide aboveground
– Grazing animals are large
Biomes
• Temperate Rain Forest
– High humidity
– High precipitation
• 2 – 3.5 m
– Relatively constant moderate temperature
• ~ 68 °F
Biomes
• Temperate Grasslands (Prairies)
– Moderate precipitation
• 0.50 – 0.88 m
– Have hot summers and cold winters
• Wildfires common in summer
– Most fertile soil
• Corn and wheat fields common
Temperate Grasslands
• Commensalism
– Cattle egret eats insects
that cows stir up
• Parasitism
– Brown-headed cowbird
lays eggs in nests of other
birds
• Competition
– Hawk and fox fight for
rabbits
Biomes
• Temperate Rain Forest
– Mosses grow and cover many of the trees
• Due to high humidity
– Animals have varied diets
• Eat any food available
• Strong jaws/beaks to eat nuts and seeds
– Tall coniferous trees
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Temperate Rain Forests
• Mutualism
– Algae and fungus create
lichens
• Commensalism
– Opossum burrows in
hole dug by woodchuck
• Competition
– Cougar and wolves
compete for elk
Biomes
• Tropical Rain Forest
– Located in a belt near the equator
– Are always humid and warm
• Receive 2 – 4.5 m of rain per year
– Fairly constant temperatures year round
– Are home to more species than any other biome
– Nutrient poor soil
• Trees provide most nutrients
Biomes
• Tropical Rain Forest
– Plants have shallow roots
• Absorb nutrients near top
– Predator plants
• Nutrients from animals, not soil
– Epiphytes
• Grow on plants, not on soil
Tropical Rain Forests
• Mutualism
– Capuchin monkeys eat
nectar, spread pollen treetree
• Commensalism
– Epiphyte grows up tree
branch to reach light
• Competition
– Orangutan and spider
monkey compete for
berries
Biomes
• Tropical Dry Forest
– High temp. year round
– Rainfall is seasonal
• 0.25 – 2 m
– Often used for agricultural land
– Less dense canopies than rain forest
Tropical Dry Forest
• Tropical Dry Forest
– Trees are deciduous
• Prevent water loss
– Some trees have chlorophyll in trunk
– Animals estivate or migrate
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Tropical Dry Forests
Biomes
• Savanna
• Parasitism
– Leeches feed on hosts
• Commensalism
– Ants live inside acacia tree
• Competition
– Trees roots compete for
water/nutrients
– High Temperatures
– Low, seasonal precipitation
• 0.50 – 1.25 m
– Full of grasses, scattered trees and shrubs
– Porous soil
– During the dry season grass fires occur and help to
replenish the nutrients in the soil
Biomes
• Savanna
Savanna
• Mutualism
– Plants store water for dry season
– Leaves grow vertically
• Less exposed to hot sun
– Some plants lose their leaves
– Animals follow rain for plants and water
– Predators follow migrating animals
– Ox peckers eat parasites
off of rhinos
• Commensalism
– Hyena eats leftovers from
lion’s prey
• Competition
– Mammals compete for
water beds
Biomes
• Desert
– Driest places on earth
• < 0.25 m
• Well-spaced storms
– Hot days, cool nights
– Nutrient-poor soils
Biomes
• Desert
– Plants are Succulents
• Thick fleshy stems and leaves that store water
– Roots are just under the surface so that they can
absorb rain quickly
– Most desert animals are nocturnal
• Air is much cooler at night
– Reptiles have scaly skin
• Prevents water loss
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Desert
Biomes
• Tundra
• Parasitism
– Fleas feed on coyote
• Commensalism
– Gopher snakes live in
abandoned rodent homes
• Competition
– Eagles and rattlesnakes
fight for birds
– Low precipitation
• 0.15 – 0.25 m
– Very cold temperatures
– Short summers with long days
• Only a few centimeters of soil thaw
– Underneath topsoil is permafrost
– Nutrient-poor soil and harsh winds
Biomes
• Tundra
Tundra
• Parasitism
– Most plants grow in little or no soil
– Most plants are short
• Absorb heat and anchor against wind
– Migratory birds fly in during summer
• Mosquitoes breed in thawed areas
– Year-long animals grow white fur
• Camouflage and warmth
Biomes
• Taiga (Boreal Forest)
– Moderate rainfall
• 0.30 – 0.84 m
– Long cold winters and short cool summers
• Average temperature < 0 °C
– Nutrient-poor acidic soil
• Slow decomposition
– Tape worm in caribou
• Commensalism
– Arctic fox eats animals dug
up by caribou
• Competition
– Hawk and wolf fight for
small mammals in winter
Biomes
• Taiga (Boreal Forest)
– Floor has few plants
– Trees are conifers with needle-like waxy leaves
• Retain water when the ground is frozen and
shed snow
– Birds fly south and animals burrow or migrate
– Some animals develop camouflage for winter
– Low biodiversity
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Taiga
Biomes
• Chaparral
• Parasitism
– Winter tick on moose
• Commensalism
– Eagle builds nest in tree
• Competition
– Bears and wolverines hunt
for rabbit
– Moderate, very seasonal rainfall
• 0.20 – 1.0 m
– Mild, wet winters and warm, dry summers
• Average temperature 0 – 20 °C
– More shrubs than trees
– Frequent fires in dry season
Biomes
• Chaparral
– Many plants have flammable oils
• Destroy competitors
– Thick leaves to stop evaporation in dry season
– Many animals are nocturnal or burrow
– Organs regulate heat
• Ex: Jackrabbit’s ears
Chaparral
• Mutualism
– Yucca and Yucca moth
• Parasitism
– Dodder chokes off
buckwheat
• Competition
– Plants start fires to clear
space for water and
nutrients
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