Biomes and Climate Change

Biome

A major geographical region with similar environmental conditions and types of life.

Ecosystem

A community of living organisms interacting with each other and their non-living environment.

Habitat

The place where an organism lives.

Factors Defining Biomes

Climate, especially temperature and precipitation, and the vegetation found in a region.

Biomes as Open Systems

Biomes exchange both matter and energy with their surroundings.

Open System

A system that exchanges matter and energy with its surroundings, such as a biome or human cell.

Closed System

A system that exchanges energy but not matter with its surroundings; Earth is an approximate example.

Tundra

A cold biome with low-growing vegetation, little precipitation, and few trees.

Taiga

• Located in regions just South of the tundra.

• Has higher temperatures and precipitation than the tundra.

• Is dominated by evergreen trees (Boreal forest).

• Many animals due to greater food source in plants

Deciduous Forest

• Found predominantly between 30°N and 60°N.

• Has a moderate climate and fairly long growing season (defined winter & summer)

• Contains deciduous trees (lose their leaves), many shrubs and a variety of animals

Grassland

A biome dominated by grasses, with relatively few trees; includes prairies and savannas.

Rainforest

A biome with abundant precipitation and dense vegetation.

Desert

A biome with very low precipitation and sparse vegetation.

Weather

Short-term atmospheric conditions that can change from hour to hour or day to day.

Climate

Long-term weather patterns of a region, usually measured over at least 30 years.

Two Major Factors Determining Biomes

Temperature and precipitation, which affect water availability and species survival.

Latitude and Temperature

Solar radiation varies with latitude; places closer to the equator generally receive more direct sunlight.

Altitude and Temperature

According to the notes, temperature drops about 4.5°C for each 1,000 m increase in altitude.

Climatograph

A graph showing a region’s temperature and precipitation together.

Biosphere as a Dynamic System

The biosphere changes over Earth’s history rather than remaining constant.

Paleoclimate

The study of past climate conditions.

Evidence of Past Climate

Glacier ice cores, lake sediments, plant fossils, tree cores, and preserved pollen.

Ice Cores

Ancient glacier ice containing trapped gases that help scientists study past atmospheric conditions.

Changes in Earth’s Tilt

A natural cause of climate change; the tilt varies from about 22.3° to 24.5°.

Greater Axial Tilt

A greater tilt makes the polar regions warmer in their summer, increasing seasonal contrasts.

Tectonic Activity and Climate

Continental movements change geographic positions and can alter local climates.

Human-Caused Climate Change

Recent rapid global warming is attributed largely to human activities.

IPCC

Intergovernmental Panel on Climate Change: established in 1988 to assess climate research and risks.

Ocean Conveyor Belt

Large-scale ocean circulation that moves water and heat around Earth.