Chapter 6 Ecosystems Section 2 Biomes A Factors

Chapter 6: Ecosystems Section 2: Biomes

A. Factors that affect biomes’ climate 1. temperature 2. precipitation

B. Major biomes – large areas with similar climates and ecosystems

1. tundra – cold, dry, treeless region a. Permanently frozen soil called permafrost b. Average winter temperature: -12⁰C c. Average precipitation is less than 25 cm per year

tundra d. Plants: mosses, grasses, small shrubs, lichens e. Animals: insects, ducks, geese, other birds, mice, arctic hares, reindeer

2. Taiga – cold forest of mostly evergreen trees a. Soil thaws in the short summer b. Precipitation: mostly snow, 35 cm – 100 cm per year

3. Temperate deciduous forests – region with four seasons, mostly trees that lose their leaves in autumn a. Temperatures range from below freezing in winter to 30°C or more in summer

b. Precipitation: throughout the year, 75 cm – 150 cm per year

4. Temperate rain forest – tall trees with needlelike leaves a. Average temperature: 9°C – 12°C b. Precipitation: 200 cm – 400 cm per year

5. Tropical rain forests the most biologically diverse of all biomes a. Average temperature: 25°C b. Precipitation: 200 cm to 600 cm per year

c. Four zones: forest floor, understory, canopy, emergents

Organisms of the forest floor

Organisms of the understory

Organisms of the canopy

Organisms of the emergent layer

d. Human impact: habitats being destroyed by farmers and loggers

6. Desert – driest biome, supports little plant life

a. Temperatures: vary from hot to cold b. Precipitation: less than 25 cm per year c. Soil: thin, sandy, or gravelly d. Plant: cactus e. Animal: kangaroo rat

7. Grasslands – prairies or plains, dominated by grasses a. Temperatures: temperate or tropical b. Precipitation: 25 cm – 75 cm per year; dry season