Biol 104 – Changing Natural Environment (Kasmer)

Review questions – Exam 4 

Exam to be given Wednesday 30 June 1999

1. Describe three important ecological services provided by wetlands.
2. What are two indirect negative effects of harvesting small numbers of very valuable trees from tropical forests in developing countries?
3. In many states, there is now legislation (wetland-mitigation acts) requiring that anyone who destroys a wetland in the course of developing a tract of land must re-create a wetland of equal area. What benefits are gained by maintaining the presence of wetlands in areas that are developed? What are the problems with this approach to conserving/preserving the biodiversity and natural structure/function of natural wetlands?
4. Describe how the Man and the Biosphere (MAB) approach to designing nature reserves helps to satisfy the multiple-use demands that are placed on natural areas by both indigenous populations, scientists, and tourists.
5. What are the advantages and disadvantages of a nature reserve that preserves several small parcels of land? What are the advantages and disadvantages of connecting different nature preserves by corridors of habitat?
6. Explain how fresh water is generated during the hydrologic cycle. What processes are responsible for purifying water, and what processes are responsible for delivering the fresh water to the earth's surface?
7. If most plants were to suddenly become extinct, how would that affect the rate at which water is cycled through the hydrologic cycle?
8. Under what conditions would you expect all precipitation produced by a cloud to reach the surface of the earth? Under what conditions would you expect only a small fraction of the precipitation produced by a cloud to reach the earth?
9. In some forested areas of the northeastern US, small pools are formed in early spring when snow melts and spring rains fall, causing the water table to rise above the soil surface in places. However, these pools often dry up rapidly in the spring - more rapidly than can be accounted for by evaporation alone. Explain the cause of the rapid disappearance of these pools.
10. Explain how toxic chemical dumped illegally in Pennsylvania could pollute an aquifer in Ohio, but not affect the aquifer lying immediately beneath the dumping site.
11. There is a large difference between the amount of water withdrawn for agricultural use and the amount that actually gets delivered to growing plants. What is the term used to describe these losses that occur during transport and delivery? What are three factors that account for some of these losses?
12. What is a cone of depression, and how can the formation of a cone of depression lead to the drying up of nearby wells?
13. What is subsidence, and what is it caused by?
14. What is saltwater intrusion, and why does it occur?
15. Describe three ways by which we can reduce our demands for water, or increase the efficiency with which we use water. At a minimum, consider agricultural and domestic uses.

Remember to look at your notes from the videos that we will watched before the exam as well.