Ch. 4.4 - Biomes

Taiga

a biome with long cold winters and a few months of warm weather dominated by coniferous evergreens; also called boreal forest

Canopy

a dense covering formed by the leafy tops of tall rain forest trees

Permafrost

a layer of permanently frozen subsoil found in the tundra

Tropical Rain Forest

contain more species than all other biomes combined, receive more than two meters of rain annually, and contain a canopy and understory

Northwestern Coniferous Forest

contains a variety of conifers, flowering trees, and shrubs with moss covering tree trunks and forest floor (sometimes called temperate rain forest).

Temperate Grassland

contains mostly grasses that grow in rich fertile soils, good for growing crops. Receives moderate seasonal precipitation

Tropical Dry Forest

have alternate rainy seasons and dry seasons, warm all year-round, and contain plants and animals that can reduce their need for water during dry periods.

Temperate Woodland

large areas of grasses and wildflowers mixed with oak and other large trees. Fire is a constant threat because of dense, low, oily plants

Tundra

mainly identified by permafrost, these areas have cold temperatures, high winds, short growing seasons, and poor humus soils that limit plant height

Humus

material formed from decaying leaves and other organic matter

Temperate Forest

mostly made up of deciduous and coniferous trees, soils are fertile and are often rich in humus. Receives moderate to cold winters, warm summers, and year-round precipitation.

Boreal Forest

often called taiga, these dense forests of coniferous evergreens are found along the northern edge of the temperate zone. They receive long, cold winters and short, mild summers

Tropical Grassland

receive more seasonal rainfall than deserts, but less than tropical rain forests. They contain mostly grass, with some isolated trees and shrubs

Desert

receives less than 25 cm of precipitation annually, can experience extreme daily temperatures alternating between hot and cold, contains many plants that store water in their tissues

Understory

the layer in a rain forest found underneath the canopy formed by shorter trees and vines