The Critical Zone

Biome Character


One manner in which to consider the term biome is as a set of ecosystems with characteristic biota—the first-order effects of climate determine the location of biomes on Earth. The interrelationship between climatic and biotic processes with the landscape and parent material determines the flow of energy, water, and nutrients in the biome. Soil and Critical Zone processes can be distinctive to a biome, thus soil and Critical Zone character and function can be considerably different from one region of Earth to another.

Reading assignment

To learn more about biomes read:

  • Chapter 30 in Raven, P. H., Evert, R. F., & Eichhorn, S. E. (1992). Biology of Plants (5th ed., pp. 657–85). W. H. Freeman.

You may also find that the following Flash animation from Teachers' Domain to be useful now and in your classroom:

As you read this chapter, reconsider briefly the information on terrestrial ecosystems presented in the Lesson 10, page 5 reading assignment.

Once you dive into Raven et al., be sure to...

  • View the global biome distribution map on pp. 658–9 and Figure 30-6 which displays the relationship between biomes and altitude (latitude)
  • Understand that the rainforest biome is typified by few individuals of many species and the most complex interrelationships between species of all the biomes—be certain to read carefully about nutrient cycling, shallow-rooted trees, and soil infertility
  • Consider . . .
    • Why are annual plants better represented in deserts than the other biomes?
    • How do winter soil temperatures in temperate deciduous forests affect the availability and movement of water to roots?
    • Why have grasslands been agriculturally exploited across the globe?
    • How are edaphic and biotic variation important in scrub biomes?
    • Which biome covers 20% of Earth's land surface?