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 Permanently frozen soil called permafrost Average winter temperature: -12⁰C c. Average precipitation is less than 25 cm per year

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

2. Taiga – cold forest of mostly evergreen trees 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 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 Average temperature: 9°C – 12°C Precipitation: 200 cm – 400 cm per year

Red panda,Tufted puffin Banana slug, platypus

5. Tropical rain forests - the most biologically diverse of all biomes 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 Rafflesia arnoldii (corpse flower) – up to 1 m across

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 Temperatures: temperate or tropical Precipitation: 25 cm – 75 cm per year; dry season