Chapter 48 Introduction

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CHAPTER 48

Biomes and Global Ecology

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Mike Hill/Getty Images.

Core Concepts

  1. Solar radiation, wind and ocean currents, and topography determine the distribution of major climatic zones on Earth.
  2. Biomes are broad, ecologically uniform areas whose characteristic species reflect regional climate.
  3. Biologically driven cycles of carbon and other essential elements shape ecology and reflect evolution.
  4. Global patterns of biological diversity reflect climate, history, and ecological interactions among species.

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Watching a movie or video, you often do not need a map to figure out where the action is taking place. Cactus and scraggly shrubs suggest the deserts of Mexico or the American Southwest; dense stands of low-growing conifers bring to mind central Canada or Siberia. The deciduous forests of eastern North America and Europe are equally distinctive, as are prairies and tropical rain forests. Plants conspicuously show that biological communities vary from place to place, reflecting the adaptations of the species that live there to local conditions of temperature, rainfall, and nutrient availability. If we take the time to survey the animals in these diverse communities, we will find that they are distinctive as well.

Biomes are broad geographic areas with similar sets of communities. Climate exerts a major influence on the nature and distribution of biomes across the globe, but before we consider this interaction between Earth and life, we must first ask what climate is and why it varies from place to place.