Chapter 5: Principles of Ecology: Biomes and Aquatic Life Zones
5.1 Weather and Climate: An Introduction
Weather refers to daily conditions such as rainfall and temperature. Climate is the average weather over a long period. Climate determines the plant and animal life of a region.
Major Factors that Determine Weather and Climate
The Earth is unequally heated, which creates three major climatic zones: tropical, temperate, and polar. Air tends to flow from the equator to the poles.
The Coriolis Effect and Topography
Weather within the major climatic zones is altered by wind flow patterns, which are profoundly influenced by the spin of the Earth. Weather is also affected by topography, especially mountain ranges.
Warm water from the equator flows toward the poles, warming landmasses near which it passes. As it flows northward, it cools. Cool water eventually sinks, and flows back toward the equator, creating a huge global circulation pattern.
5.2 The Biomes
The Earth’s surface can be divided into biologically distinct zones called biomes, each with a distinct climate and unique assemblage of plants and animals. Nevertheless, regional variations occur within each biome.
The Arctic tundra, the northernmost biome, is characterized by the harshest climate. Because the growing season is so short, life on the Arctic tundra is extremely vulnerable to human actions.
The taiga is a band of coniferous trees spreading across the northern continents just south of the tundra. Its climate is milder and its life forms are more diverse than those of the tundra. The taiga supports many large populations of wild animals, but the forests of this region are under heavy pressure to meet rising demands for wood and wood products.
The Temperate Deciduous Forest Biome
The temperate deciduous forest biome occurs in regions with abundant rainfall and long growing seasons. This biome has been heavily settled by humans and...