CHAPTER 2 - SECTION 4 BIOMES
What are Biomes?
Biomes are regions in the world that share
similar climates and organisms.
How Many Biomes Are There?
Scientists disagree over the exact number of
biomes, but in general they include around 810 biomes. We will focus on 6 land biomes.
The six major biomes that most
ecologists study include:
Rain Forest, Desert, Grassland, Deciduous Forest,
Boreal Forest and Tundra
WE CLASSIFY DIFFERENT BIOMES MOSTLY BY CLIMATE
(TEMPERATURE AND PRECIPITATION) AND BY THE
ORGANISMS THAT LIVE IN THE AREA.
Rain Forest Biomes
• Temperate Rain Forests:
Moderate temperatures (average = 500F)
Found on the northwestern coast of the United
States. (Olympic Rain Forest in Washington)
Receive more than 300 centimeters of rain per year.
Huge trees and abundant wildlife.
Temperate Rain Forests US
Temperate Rain Forest Life
• Tropical Rain Forest
Over 100 inches (250 centimeters) of rain per year
Warm and humid (between 68 – 930F) all year
More species of plant and animal life than the other
land biomes
Tropical Rain Forests
Tropical Rain Forest Life
Desert Biomes
Receives less than 25 centimeters of rain per year
Average yearly temperature is 640F
Large shifts in day and night temperatures
Plants and animals must adapt to extreme
temperatures and dry conditions.
Desert Biomes Life
Grassland Biomes
Grasslands = Prairie and Savanna
25 to 75 centimeters of rain per year (Savanna can
get as much as 125 cm of rain per year)
Temperatures mostly comfortable and mild than
the desert but can reach 1000 F in summer and 300F in winter.
Plants include mostly grasses, small shrubs and
trees
Grazing animals – Some of the largest in the world
(Elephants, bison, giraffes, rhinos)
World Grasslands
Grassland Biomes Life
Deciduous Forest Biomes
Deciduous, hardwood trees that lose their
leaves in the fall
At least 50 centimeters of rain per year and
seasonal temperatures that vary
Average temperatures of 500 F however well
below freezing in winter
Large variety of plant and animal life
World Deciduous Forest Map
Boreal Forest Biomes
Also called the TIAGA!
Cold forest
30 – 85 centimeters of rainfall per year
-650 to 300 F in winter About 500 F in summer
Most trees are coniferous (pine cones and needles
for leaves) Spruce, hemlock and tamarack trees
Seed eating animals, predators and herbivores
Boreal forests, or taiga
Taiga Plants
Balsam Fir
Paper Birch
Black Spruce
Douglas-fir
Eastern Red Cedar
Jack Pine
Siberian
Spruce
White Fir White Poplar
White Spruce
Taiga Animals
American Black Bear
Canadian Lynx
Long-Eared Owl
Snowshoe Rabbit
Bald Eagle
Gray Wolf
Bobcat
Grizzly Bear
Red Fox
River Otter
Wolverine
Tundra Biomes
Coldest of the biomes
40 centimeters of precipitation per year
Winter temperatures average – 340F Summer temps
average 37 – 500 F
Soil is permafrost – frozen all year
Plants are dwarfs, stunted by the cold
Mosses, grasses, shrubs and small trees
Animals must adapt to extreme cold temperatures
Caribou, foxes, wolves, Arctic hares
Tundra: The Not-So Barren Land
Tundra Biomes Life