Terrestrial biomes

biome

• Definition- a major type of ecosystem with distinctive temperatures, precipitation, and organisms

Major terrestrial biomes

• Desert• Tundra• Deciduous forest• Evergreen forest (taiga)• Rainforest• Steppe• Prairie

Desert biome

• Precipitation = 0 to 10 cm per year• Most rain comes in a few thundershowers• Lack of water makes desert cool at night• 2 types of deserts

– Cool (like deserts east of Rocky mtns.)– Hot (like deserts in Arizona and New MexicoTemperatures can go from 100 degrees F. to 40

degrees F. in same day

Desert plants

• Store water in tissues• Shallow, wide roots• Many have spines• The plant at right is

the prickly pear cactus

Old man cactus & aloe vera

Desert animals

• Get water from food• Some live

underground• Some are nocturnal• Some have large ears

to radiate heat• Animal at left is a

fennec from Africa

Thorny devil (Australia) & sidewinder (southwestern U.S.)

Sahara desert

Tundra biome

• Cold, windy & dry• Fewest organisms of any other biome• Short growing season (60 days)• Permafrost – only top 8-10 cm of soil thaw

in summer, area below stays frozen• Less than 25 cm of precipitation per year

Tundra plants• Tundra plants are

small, shallow-rooted, and grow close to ground

• Willow trees grow only 1 meter tall from wind and limited space

• Most are mosses, lichens, wildflowers, and grasses

Tundra animals

• Most have thick coats and wide feet

• Migration – seasonal travel to find food

• No reptiles or amphibians

• Many migratory birds (few predators there)

caribou

Lemming

evergreen forest (taiga) biome

• Warm summers, long, cold winters• 40 to 200 cm precip. per yr.• Usually found on high mtns. of N. Amer.,

Europe, and Asia• Soil is poor because of slow decomposition of

needles• Snow insulates soil from freezing

Taiga plants• Trees have wax-covered

needles to shed snow and hold moisture

• Ferns and lichens grow in dim light on forest floor

• Most taiga trees produce cones that contain seeds

• Tree at left is a black spruce, often used as a Christmas tree

Larch and jack pine (conifers)

Taiga animals

• Most adapted to cold & snow

• Small rodents live under snow

• Many large herbivores & predators

moose

lynx

wolf

Deciduous forest biome

• Receives 50 to 300 cm precip. per yr.• Temps. range from 30 deg.C to -30 deg.C• Trees drop leaves in winter to conserve water• 6 month growing season• 3 layers:

– Canopy (highest layer)– Understory (younger, smaller trees)– Floor (shrubs, ferns, mosses)

Deciduous forest plants

• Rich soil (humus) from falling leaves

• Many are colorful in fall and winter

• Tree on the right is a Japanese maple

Red oak and sugar maple

Deciduous forest animals

• Diverse group of predators & herbivores

• Adapted to cold• At right is a raccoon

Pileated woodpecker and white-tailed deer

Red fox and porcupine

Rain forest biome

• Average temp. is 25 deg. C year-round• Precip ranges from 200 to 450 cm per yr.• 12 month growing season• Most diverse plants & animals of any biome• Contain 70% of all terrestrial species but cover

only 6% of earth’s surface• Canopy catches 99% of light hitting the forest• Soil is poor – warmth & moisture cause rapid

decay of dead matter

Rainforest plants• Shallow-rooted from

poor soil• Some are epiphytes

(live by hanging from trees)

• Many exotic species of wood – teak, mahogany, balsa

• Left is a mahogany guitar body

Koli’I and orchid

Rainforest animals

• Adapted to different layers of forest

• Some are arboreal (live entire life in trees)

• Bird on right is bird-of-paradise

Red-eyed frog & spider monkey

Toucan & sloth

Kinkajou & rainforest possum