2-15: Vegetation Responses to a Changing Environment

Pre-Class Preparation

Objectives

• To understand the basic relations between elements of climate change and use of carbon dioxide and water by plants.
• To explore some simple concepts of how plants facilitate the flow of carbon between the atmosphere and soil and contribute to the global carbon cycle.

Procedure

1. Read the learning unit.

   Class images

2. Take the learning unit quiz. Quizzes are available from your portfolio. You may access your portfolio via the list of students participating in this years course, as represented by the icon below.
   
   
3. Additional Required Reading. Although you are not ultimately responsible for content listed in this section, we encourage you to fully explore the links in order to provide a better scope on the upcoming class discussion.

   	Houghton, J. T., L. G. Meira Filho, B. A. Callander N. Harris, A. Kattenberg, and K. Maskell, 1996: Climate Change 1995. The Science of Climate Change. Cambridge University Press, 454-469.
   	Houghton, J. T., G. J. Jenkins, and J. J. Ephraums, 1990: Climate Change, The IPCC Scientific Assessment. Cambridge University Press. p. 289-306.
   	What is the economic value of the global ecosystem? The 15 May 1997 issue of Nature magazine (Volume 387 no 6230) raises this question: "What is the global ecosystem worth? Or, to put it another way, how much would we have to pay for the goods and services the Earth currently provides for free? An alliance of ecologists and economists has estimated the annual value of the services provided by the Earth's ecosystem at $33 trillion, or about twice global gross national product."

Class Discussion

• Problem to ponder...
  Trees do not permanently remove carbon from the atmosphere, so why is reforestation considered one of the major methods of coping with increased atmospheric carbon dioxide?

• Class Discussion Summary: by your classmate Mark A. Nauman

  The topic of the class was "Vegetation Responses to a Changing Environment." Several definitions to key words and abreviations were covered so that those students not familiar with the terms would now have that knowledge. Following a brief introduction of the subject, climatic driving forces such as solar radiation, temperature, precipitation, air humdity and atmospheric CO2 were discussed. The effects that each of these factors have on plant growth and development were then discussed in detail. It was then stated that land use and development has a greater impact on soil carbon dynamics and soil biodiversity then any or all of the climatic forces. The next topic was ecology. Changes in ecological processes are difficult to predict and ecosystems are destroyed by either the loss of species within the ecosystem or by the invasion of alien species. A reference was then made to "Ciesin Thematic Guides." The guides refer to the loss of biodiversity as taking place because of human impacts, destruction of critical habitats, species be forced to extinction or the invasion of non-native species. The last piece of information was that species are becoming extinct at a rate of one million times faster than species are being created.

Post-Class Activities

• Participate in the electronic dialog. Use this forum for:
  • continuing class discussion;
  • posing new questions to students or the instructor;
  • responding to issues/questions raised by students in class/electronic dialog.

  Visitor Access (Visitors are welcome to participate in the dialog. Just click on the icon below)	Student Access (Students must post all dialog from their portfolio. Click on the icon below to access the student list.)

• Recommended Reading Materials

  	Biological diversity: a CIESIN thematic guide.
  	Houghton, J.T., G.J. Jenkins, J.J. Ephraums, eds, 1990: 1990 Intergovernmental Panel on Climate Change, Cambridge University Press, 300-306.
  	Root, T. L., and S. H. Schneider, 1995: Ecology and Climate: Research Strategies and Implications. Science 269, 334-341.
  	Root, T. L., and S. H. Schneider, 1993: Can Large Scale Climatic Models be Linked With Multi-Scale Ecological Studies? Conservation Biology 7, 256-270.

• References

  	Tans, P. P., and J. W. C. White, 1998: In balance, with a little help from the plants. Science 281, 183-184.
  	Falkowski, P. G., R. T. Barber, and V. Smetacek, 1998: Biogeochemical controls and feedbacks on ocean primary production. Science 281, 200-206.
  	Biodiversity Glossary of Terms
  	Cohen, Joel, 1995: Population Growth and Earth's Carrying Capacity. Science 269, 341-346.