Questions for Lecture 10:  Ecosystems: Dynamics of Ecosystems; 
        Energy flow and Productivity

•  By the end of your preparation on this topic, you should be able to:

    © 1. Define ecosystem, and describe the emergent properties of an ecosystem.

    © 2. Describe the meaning of trophic levels, differences between primary producers and the
               consumers, and the food chain and the food web.

    © 3. Describe energy transformation among trophic levels, and relate it to the concept of
               ecological efficiency, and of the ³pyramids² of (a) numbers; (b) biomass; and (c) energy.

    © 4. Describe the change in the net primary productivity (NPP) through time for a forest
               ecosystem and identify possible factors determining these changes.

    © 5. Distinguish between the NPP, gross productivity (GPP) and the biomass of an
               ecosystem.  What factors control NPP?

    © 6. Present the reasons for differences in the productivity of different ecosystems in     terms
               of net primary productivity, and in the percentage contribution to Earth¹s     productivity.
 
• Outline of presentation :
            For outline of presentation and for the legends of figures, see  the Handbook for the course "Biology 121 Notes, Spring, 1998, University of Illinois, Plant Biology: Ecology and Organismic Plant Biology" by Govindjee, Stipes  Publishing, Champaign,IL.
 
    © Slides used in the class are to be found elsewhere on these Web pages.