The Critical Zone

Considering Adaptive Actions in the Critical Zone


From the introduction to this lesson, remember that human actions can be adaptive or excessive—thus far, much of our activity has been excessive, but we have the capacity to adapt and to be sustainable.

Reading assignment

NOTE: The following readings are all available through Library Reserves.

  1. Read the following National Geographic article for a broad overview of excessive and adaptive actions by human society, including in the past. The article mentions activities leading to compaction, erosion, and loss of nutrients and organic matter, to name a few. Consider what human actions might be included in your Critical Zone system model.
    • Mann, C. (2008). Our Good Earth. National Geographic, 214(3), 80–106.
  2. Continue your reading by considering the final article from the special "Soils—The Final Frontier" section from the journal Science. The article describes interactions between soil organic matter and atmospheric carbon dioxide and the global carbon cycle and explores human adaptive strategies that could increase soil organic matter content and fertility while also removing and storing carbon.
    • Lal, R. (2004). Soil Carbon Sequestration Impacts on Global Climate Change and Food Security. Science, 304(5677), 1623–1627.
  3. Finally, read Jon Chorover's Elements article to learn about the role of soil biota and biogeochemical cycles in affecting the fate of contaminants in the Critical Zone. Jon is a soil scientist at the University of Arizona and is also a steering committee member for CZEN.
    • Chorover, J., Kretzschmar, R., Garcia-Pichel, F., & Sparks, D. L. (2007). Soil biogeochemical processes within the critical zone. Elements, 3(5), 321–6.

Check it out . . .

Here are some additional resources that might be of interest:

  • A National Geographic article entitled "Dirt Poor" follows the "Our Good Earth" article. Read this one for an example of the dire consequences of ignoring soil resources—in our own backyard!
    • Bourne, J. (2008). Haiti Soil: Dirt Poor. National Geographic, 214(3), 108–11.
  • View the video entitled "Organic Farming: Conserving Topsoil" for an interesting look at one adaptive strategy.