1. Maintaining Biodiversity

2. Have we overstated the tropical biodiversity crisis? William F. Laurance Trends in Ecology & Evolution Vol. 22: 65-70 February 2007

3. Extinction rates are likely to be higher in biodiversity hotspots

4. Fig 55.4 Terrestrial Biodiversity Hotspots

5. the 16 hotspots that sustain tropical forest have already lost, on average, 90% of their forest cover

6. Are we on the verge of a massive die-off of tropical species?

7. Changes in Extinctions and Diversity

8. Increased rural density leads to decreased forest.

9. This is because rural slash- and-burn farmers cause most forest loss.

10. The good news? About 21–24% of species in the Asian tropics and 16–35% of species in the African tropics are threatened with possible extinction.

11. Rural populations are expected to decline.

12. Substantial areas of agricultural land are likely to be abandoned, because the population growth rates of many developing nations are slowing and because of increasing urbanization. This could enable significant forest regeneration, which could help buffer species losses from deforestation.

13. Human vs Natural Disturbances

14. Rainforest clear cutting

15. Not all habitats are equal

16. A third to a half of all old- growth species avoid younger (<30-year-old) regrowth.

17. In many tropical regions, future pressures on forests will be determined more strongly by industrial drivers, globalization and macroeconomic forces than by local population density.

18. Rural populations are expected to decline, but increased urban population will demand more resources.

19. The precautionary principle maintains that one should err on the side of caution in conservation matters.

20. We need to evaluate critically the degree to which regenerating and degraded habitats, which are increasing dramatically at the expense of old-growth forests, can sustain tropical biodiversity

21. How many animals do we need to save?

22. How Many Animals Do We Want to Save? The Many Ways of Setting Population Target Levels for Conservation ERIC W. SANDERSON November 2006 / Vol. 56 No. 11 BioScience 911

23. Extinction Vortex A population of a few individuals cannot survive

24. Can a number of individuals be set?

25. Fewest number of individuals for an area, but fewest number for what?

26. Can a number of individuals be set? Extreme examples: Ecotourism want the largest possible population Mining or Agriculture would like none or somewhere else…NIMBY

27. What are the consequences of setting the wrong number?

28. Too high Too low

29. Can a number of individuals be set? Scientists are reluctant to set a specific number Policymakers want information from scientists

30. What are the consequences of setting the wrong number? Subjective values meets objective science

31. http://www.forwolves.org/ralph/historical.html Yellowstone area wolf packs 2004 How many wolves should be in Yellowstone NP

32. How many tigers does the world need? None?

33. What criteria do we use to set limits? Money Land Development

34. What criteria do we use to set limits? Money Land Development Who benefits? Animals- what is the minimum number for sustainable survival Animals- what is the minimum number for sustainable survival

35. What criteria do we use to set limits? Money Land Development Who benefits? Animals- what is the minimum number for sustainable survival Animals- what is the minimum number for sustainable survival Ecosystem- What is the minimum number to maintain a healthy ecosystem? Ecosystem- What is the minimum number to maintain a healthy ecosystem?

37. What criteria do we use to set limits? Money Land Development Who benefits? Animals- what is the minimum number for sustainable survival Animals- what is the minimum number for sustainable survival Ecosystem- What is the minimum number to maintain a healthy ecosystem? Ecosystem- What is the minimum number to maintain a healthy ecosystem? Humans- How many do we need to derive some beneifit? Humans- How many do we need to derive some beneifit?

38. Bonuses due... now