Biomes
The biosphere is divided into region called biomes.
A Biomes is a group of ecosystems that exhibit
common environmental characteristics .
Earth’s Biomes
1.
2.
3.
4.
5.
6.
7.
8.
9.
Tropical Rain Forest
Desert
Temperate Grasslands
Savannas
Temperate Deciduous Forest
Conifer Forest-Taiga
Tundra
Marine
Freshwater
Earth’s Biomes
Tropical Rain Forest
• High temp
• Heavy rainfall
• Tall trees that branch at their tops
forming canopies
• Very little light reaches the floor
• Epiphytes and vines
• Equatorial
– 4% of Earth’s land surface
– Account for 20% of Earth’s net carbon
fixation
• Most diversity of species of any
biome
• Animals:
– Birds, reptiles, mammals, amphibians
Desert
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Hot & dry
Less than 10” of rainfall per year
Extreme temperature fluctuations
Plants:
– Cactus, sagebrush
– CAM plants
• Modification for water storage
• Animals:
– Rodents, kangaroo rat, snakes, lizards,
arachnids, insects, and few birds
Temperate Grasslands
• Low annual rainfall
• Grazing mammals (bison, antelope), burrowing
mammals (prairie dogs & other rodents)
Temperate Grasslands
• Warm to hot summers, cold winters, moderate,
seasonal prec, fertile soils, fires
• Dominant plants: lush, perennial grasses and herbs,
resistant to drought, fire and
• Dominant wildlife: predators (coyotes, badgers,
wolves, grizzly bear); herbivores (deer, antelope,
rabbits, prairie dogs, bison); birds (hawks, owls,
bobwhite), insects (ants and grasshoppers)
• Geographic distribution: central Asia, N.A.,
Australia, central Europe, upland plateaus of S.A.
Savannas
• Grasslands with scattered trees
• Warm temps, seasonal rainfall, compact
soil, frequent fires due to lightning
• Tropical, less rainfall than rain forest
Savannas
• Dominant plants: tall, perennial grasses, droughtand fire-resistant shrubs and trees
• Dominant wildlife: predators (lions, leopards,
cheetahs, hyenas, jackals), herbivores (elephants,
giraffes, antelopes, zebras), birds (eagles,
ostriches, weaver birds, storks), insects (termites)
• Geographic distribution: large parts of eastern
Africa, southern Brazil, northern Australia
Temperate Deciduous Forest
• Cold to moderate winters, warm summers, yearround precip, fertile soil
– 70-150 cm annual precip
• Dominant plants: broadleaf deciduous trees, some
conifers, flowering shrubs, herbs, mosses and ferns
– Broad-leaved hardwood trees that shed their leaves each
year
– Soil has top layer that is rich in humus, deeper layer of
clay. If minerals are not taken up by plants roots, the
minerals get into clay and are trapped
Temperate Deciduous Forest
• Dominant wildlife: deer, black bears,
bobcats, nut and acorn feeders, omnivores
(raccoons and skunks), songbirds, turkeys
• Geographic distribution: eastern U.S.,
southeastern Canada, most of Europe, parts
of Japan, China, and Australia
Conifer Forest-Taiga
• Long, cold winters; short, mild summers; moderate
precip; high humidity; acidic, nutrient-poor soil
– A little warmer and wetter than tundra, but long, severe
winters and short,mild summers
– NO PERMAFROST layer, but decay of evergreen needles
makes soil acidic and mineral-poor
• Dominant Plants: needleleaf coniferous trees,
broadleaf deciduous trees; small, berry-bearing
shrubs
Conifer Forest-Taiga
• Dominant Wildlife: predators like lynx
and timberwolves; weasel family;
herbivorous mammals (large and small);
beavers; migratory songbirds
• Geographic distribution: N.A., Asia,
Northern Europe
Tundra
• Strong winds;low precip;short and soggy summers;
long, cold, dark winters; poorly developed soils
– Permafrost present – permanently frozen ground under
the topsoil
• Dominant Plants: mosses, lichens, sedges, short
grasses (ground-hugging)
Tundra
• Dominant wildlife: birds and mammals
that can withstand harshness; migratory
waterfowl, shore birds, musk ox, Arctic
fox, caribou; small rodents
• Geographic distribution: northern N.A.,
Asia and Europe
– Closest to poles
Aquatic Biomes
~Marine~
• Oceans contain the largest amount of living
material (biomass) of all of the biomes – but
most of them are microscopic orgs!!!
• Since oceans are huge, studied based on light
penetration:
– --photic zone (shallow, lots of light available)
– --aphotic zone (deep, never receive sunlight)
Estuaries and Tidal effects
• Estuary – found on coast, partially surrounded by
water; here, salt water and fresh water mix.
•
*see variations in SALINITY – salt
concentration, so what grows/lives here varies
enormously.
Intertidal Zone
• Tides – gravitational pull of sun and moon
causes the rise and fall of ocean.
• INTERTIDAL ZONE – portion of shoreline
between high and low tide zones
•
*high levels of sunlight, nutrients, and
oxygen, but low PRODUCTIVITY due to
waves and movement
Aquatic Biomes
~Fresh water~
EX. Lakes, ponds, rivers, streams
• Light penetration still affects productivity
– photic zone has high productivity,
– aphotic zone has low productivity
• But, bottoms of lakes and ponds have decay taking
place (dead orgs drift to bottom, bacteria break
them down and form detritus), so importance in
CYCLES is enormous…
Earth’s Biomes