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This article explores the economic value of ecosystem services and the benefits of marine reserves in preserving biodiversity. It also discusses the challenges of habitat fragmentation and the implications for species richness.

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Announcements

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  1. Announcements • Reading Assignments • BSCI363: Chapters 4 and 5 • CONS670: Chapters 8 and 15

  2. Tragedy of the Commons

  3. The Value of Ecosystem Services Costanza, R et al. 1997. The value of the world's ecosystem services and natural capital. Nature 387:253-260.

  4. Deforestation of the Seafloor • The area of seabed trawled worldwide is ~ 150 times greater than the area of forest clearcut each year (an area twice the size of the lower 48 United States). • Although some spots escape trawling by chance or because they don't have fish, each square foot of the world's continental shelves is trawled every ~ 2 years Watling et al. 1998. Disturbance of the seabed by mobile fishing gear: a comparison with forest clearcutting. Cons. Biol. 12. 1180-1197. http://www.mcbi.org/btrawl/wnpaper.html

  5. Marine Reserves • Based on a review of more than 100 marine reserves • population densities were on average 91% higher • biomass was 192% higher • average organism size was 31% higher • species diversity was 23% higher • Responses tended to be rapid (1-2 years after protection) and persistent (> 40 years). The Scientific Theory of Marine Reserves. AAAS Session: Science and the Biosphere, 2001.

  6. Marine Reserves • Reserves may contribute to recruitment both inside and outside of reserve boundaries • Fisheries interests should benefit from this spillover, recruitment enhancement, and sustainable harvest. The Scientific Theory of Marine Reserves. AAAS Session: Science and the Biosphere, 2001.

  7. Outline • Ecosystem Ecology • Biodiversity and ecosystem services • Ecosystem services • The economic value of ecosystem services • Biodiversity Management • Equilibrium Theory of Island Biogeography • Modern Approaches

  8. Habitat Fragmentation

  9. Species Area Curves S = CAZ (log S) = Z (log A) + (log C) From: Gotelli, N. J. 1995. A primer of ecology. Sunderland, MA: Sinauer Assoc. 1-206 p.

  10. Equilibrium Theory of Biogeography Species richness on islands or habitat patches is a balance between colonization and extinction

  11. Colonization Dynamics Mainland pool of spp., “P” Colonization Island spp., “S” P # Island Species C declines to 0 where # island species = P (no more colonists available)

  12. Extinction Dynamics Mainland pool of spp., “P” Extinction Island spp., “S” P # Island Species E is proportional to the total number of species. E reaches its maximum value at P

  13. Turnover Dynamics and Island Spp. Richness Turnover (i.e., E or C) Extinction T S Colonization P # Island Species T = point where extinction rate = colonization rate. T determines the species richness for an island (S).

  14. Nonlinear E and C Pattern and conclusions are identical for linear and nonlinear E and C Turnover (i.e., E or C) Turnover (i.e., E or C) E E T T S S C C P P # Island Species # Island Species

  15. Review: Metapopulation Models • E decreases as patch size (area) increases. • C increases as distance between patches decreases.

  16. Area Effect Turnover (i.e., E or C) ES P EL SS SL Colonization SS SL # Island Species P

  17. Distance Effect Turnover (i.e., E or C) P CN Extinction CF SN SF SN SF # Island Species P

  18. Number of Species on an Island Turnover (i.e., E or C) P CN ES CF EL SNS SNL SFS SNS SFL SNL SFS SFN P # Island Species

  19. Application of Island Biogeography The good, the bad, and the ugly . . .

  20. Distance and Species Richness From: Gotelli, N. J. 1995. A primer of ecology. Sunderland, MA: Sinauer Assoc. 1-206 p.

  21. Contributions of ETIB • Metaphor of refuge as an island or spaceship • Interest in the fragility of the biota of individual refuges and causes of this fragility • Rules of refuge design? Hanski, I. A., and G. M.E., editors. 1996. Metapopulation biology: ecology, genetics, and evolution. San Diego, CA: Academic Press. 512 p.

  22. “Island Biogeographic” Reserve Rules: IUCN, WWF Good: Make reserve as large as possible Bad: Scaling is species / process specific Ugly: Abandon small reserves ? Good: Potentially increase connectivity Bad: Effectiveness remains unclear Ugly: Increase synchrony of populations ? Good: True for spp. w/ large range req. Bad: False for spp. w/ small range req. Ugly: Not based on ETIB ? Good: True for “interior” spp. Bad: False for “edge” spp. Ugly: Not based on ETIB

  23. Fundamental Problems w/ ETIB? • Alternative explanations for species-area relationship • Sampling • Habitat diversity • How do we define TURNOVER? Species Area (Samples)

  24. ETIB and Forest Reserves Pimm, S. L. 1998. Ecology: The forest fragment classic. Nature 393:23-24.

  25. ETIB and Forest Reserves • Spp. lost in small fragments • Top predators • Primates • Army ants and company • What about frogs? • Limited by breeding sites • Peccaries

  26. Reserve Rules vs. Reality • Reserve design will be species specific. • Reserve design will be site specific. • The idea of “optimal” reserve design may miss the point entirely. • We are rarely faced with these alternatives. • ETIB is considered by many to be a “false start” in Conservation Biology

  27. Application of ETIB • Application of ETIB to reserve design has been widely criticized • “Faunal collapse” refers to the loss of species following insularization. • Broadly accepted • Basis for many estimates of extinction rates • Caveats • Considerable error when used for prediction

  28. Extinctions of large mammals in parks and reserves Newmark, W. D. 1995. Extinction of mammal populations in western North American national parks. Conservation Biology 5: 67-78.

  29. Application of ETIB McDonald, K. A., and J. H. Brown. 1992. Using montane mammals to model extinctions due to global change. Conservation Biology 6: 409-415.

  30. Application of ETIB McDonald, K. A., and J. H. Brown. 1992. Using montane mammals to model extinctions due to global change. Conservation Biology 6: 409-415.

  31. Application of ETIB McDonald, K. A., and J. H. Brown. 1992. Using montane mammals to model extinctions due to global change. Conservation Biology 6: 409-415.

  32. Community Ecology and Conservation: Nested Communities

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