VI. Ecosystems

•Ecosystem – a group of plants and animals that depend on each other and their environment for survival.

• They can be very large or extremely small

• can change over time due to physical processes or human activities.

• for example, lack of rainfall in a temperate forest or the building of a city.

A. Types of Ecosystems

Tropical or Subtropical Forest

•Steady hot temperatures and moist air

• vast, thick areas of trees

• rainfall is common

Temperate Forest

•Moist temperate climates support thick forests of deciduous trees.

• Deciduous Trees – trees that lose their leaves in the fall.

• Some temperate forests include a mix of deciduous and evergreen trees.

Subarctic Forest

•Coniferous Trees – trees that produce cones to carry seeds.

• These trees contain needles

• needles protect trees from the cold dry winters of subarctic climates.

Tropical or Subtropical Grassland or Savanna

•Savanna – is a park-like landscape of grasslands with scattered trees that can survive dry spells.

• Savannas are found in tropical areas that have dry seasons.

Temperate Grassland and Brush

•Vast grasslands cover most of the region

• contains more rainfall than desert ecosystems.

• However, not enough rain to support forests.

Mediterranean Brush

•Shrubs and other low plants in Mediterranean climates hold in water.

• This is to help plants survive hot, dry summers.

Desert and Desert Brush

•Dry semiarid areas and deserts with some rain.

• support animals and low-lying desert plants.

• plants need little water and can live in extreme temperatures.

• driest of desert areas have little or no plant life.

Mountain Grassland and Brush

•Vegetation depends on elevation.

• temperatures drop as altitude increases.

• the higher the elevation, the fewer plant and animals there are.

Tundra

•The tundra is an area of cold climate and low-lying plants.

• grasses grow and low shrubs bloom during brief, cool summers.

• animals survive in cold temperatures with little food.

Ice Cap

•Thick ice caps form around the poles

• year round climate of extremely cold temperatures.

• no plant life exists on this ice.

Global Warming?