Questions for exam III.

For all the below consider carefully... go back after your intial thoughts and reading from the notes and text. Make sure you use both sources. The answers are not necessarily

1. Contrast the players and the turnover rates of energy flow in the 3 regions of the serpentine: barrens, pine and decidous forests. Include in your answer the concepts of control of turnover rate, primary and seconday production, role of detritial line vs grazers. Be as thorough as possible in contrasting the 3 areas.. go back to notes on succession and attributes..

2. Create a STELLA model on paper to better describe how predation works. What parameters are involved that control predation rates, winner and losers. Use the following true story as a base for your model. How might a running version of your model help US govt to help all survive?

Protected status proposed for Aleutian sea otters By Yereth Rosen Friday, November 10, 2000 The disappearing population of sea otters along Alaska's Aleutian Islands would get special protection under a Fish and Wildlife Service proposal announced Thursday. Aleutian otter counts have fallen by 70 percent since 1992, according to Fish and Wildlife Service surveys. As few as 6,000 of the playful mammals may remain along the 1,000-mile stretch of islands arcing across the Pacific Ocean. "They're not doing well," said Karen Boylan, a spokeswoman for the service's Alaska office. In the 1980s, the Aleutian population was estimated at 50,000 to 100,000, she said. The Fish and Wildlife Service proposal, which would give the Aleutian otter Endangered Species Act protection, was published Thursday in the Federal Register. Biologists studying the animals say a leading suspect in the decline is the area's population of orcas, or killer whales, which have been recently observed eating otters. Agency biologist Doug Burn said if orcas are responsible for the sea otter problems, an Endangered Species Act designation would not halt that behavior. But he said it might let the agency take other action to protect the otters. The vanishing sea otter population has had ripple effects on the Aleutian ecology, Burn added. The otters eat sea urchins, for example, and sea urchins eat kelp. With fewer otters, the urchin populations are booming and kelp forests are in decline. Alaska's sea otters were hunted to near-extinction by Russian and American fur traders in the 1700s and 1800s because of their plush fur, dubbed "soft gold." Commercial hunts continued until 1911, when the International Fur Seal Treaty gave protection to the isolated otter populations that remained. The otters never fully recovered in their entire West Coast range. But Alaskan populations bounced back, including in the southeast, where they are thriving despite a healthy orca population, Boylan said. She also said establishment of critical habitat protections for the otters would be unlikely to affect the commercial fish harvest, as has been the case with other protected species, such as sea lions. She said the otters live too close to shore to interfere with the $1 billion harvest of pollock and other groundfish in the Bering Sea and Gulf of Alaska. Business advocates were wary of possible sea otter protections, nonetheless. "There's reason to be concerned about yet another ESA (listing) and we need to look at the implications," said Ken Freeman, executive director of the Resource Development Council of Alaska.

3. Carefully consider how both parasitism and mutualism could help increase species biodiversity. Why would we expect to see more biodiversity in the tropical rain forests in general and b. would there be a greater percentage of parasites and mutualistic relationships than in less diverse systems?

4. Biogeochemistry: Go back ( as many of you need to any way) and look at the nitrogen and phosphorous data in the serpentine. Why did we look at the 3 forms of N? why the low levels of phosphorous? which is more limiting - N or P? how are the turnover rates different? what roles do lichens play? How does acid rain affect the cycling of these atoms? do you have any evidence to back this up?

5. How would herbivory defenses by plants ( biochemical and morphological) impact foraging strategies by animals? Go back to the foraging models... consider all the parameters that affect foraging rates. Now consider plant evolution of defenses. What would be the best way energetically for plant to reduce foraging by herbivores?

6. Every natural park manager must deal with the fact that systems undergo succession. Is their job to maximize biodiversity by maintaining a complex or mosaic environment via burning etc. or basically to let the system goes as it wants? Even if alien species come in? How much control should a manager attempt? should s/he be more concerned with the plant or animal life considering the 2 divergent views of Clements and ... .

7. When we consider animal defense systems:

a. Consider the vinegaroo beetle vs. the little beetle with funny legs. First explain how each defense mechanism works. b Evolutionarily what should be cheaper to evolve... behavioral responses, biochemical or structural... to decrease predation. Why isn't one method used more exclusively? Why is it difficult to evolve new morphology for better defense?