2. Habitat fragmentation = the breaking apart of continuous habitat 1. reduction in the total amount of original habitat (i.e. habitat loss) 2. subdivision of the remaining habitat into fragments, remnants, or patches (i.e. habitat fragmentation) 3. introduction of new forms of area-use to replace lost habitat

3. Stages of Landscape Change 1. Intact landscapes 2. Variegated landscapes 3. Fragmented 4. Relict landscapes McIntyre and Hobbs (1999)

4. Species-Area Relationships Relationship between the size of a habitat (or “island”) and the number of species present Generally, for every 10x increase in habitat area you can expect a doubling in species abundance

5. Theory of Island Biogeography Preston (1962) and MacArthur & Wilson (1963, 1967) Proposed that the number of species on an island is in a dynamic equilibrium between immigration and extinction

6. Island Biogeography: Area Effect

7. Island Biogeography: Distance Effect

8. Island Biogeography and Conservation Areas of application: How large should preserves be? How does isolation affect species number in reserves? What kinds of species will survive if area is reduced?

9. Fragmentation and its Effects on Community Structure Loss of species richness Changes in species interactions Changes to trophic levels Loss of foundation species

11. Edge Effects High perimeter length to area ratio Greatest effects occur in small remnant areas and those with complex shapes

13. Deterministic and Stochastic Processes Deterministic = factors that are not necessarily a direct consequence of habitat fragmentation but arise from land uses typically associated with it. Stochastic (chance) = natural factors related to demographics, genetic variation, environmental fluctuations, catastrophic events

14. Effects of Isolation Impairs regular movements of organisms Impairs seasonal/migratory movements Impairs dispersal movements

15. Metapopulations Local populations interconnected by movements of individuals between them

19. Salt Marsh Habitat Fragmentation, Degradation and Loss

21. Problems Facing Salt Marshes Agriculture Channelization Flood control/Levees Roadways Development

22. Case Study: Louisiana http://gallery.usgs.gov/search/

23. Case Study: Louisiana

25. Seagrass Habitat Fragmentation, Degradation and Loss

30. Prop Scars!

31. Coral Reef Habitat Fragmentation, Degradation and Loss

35. Mangrove Habitat Fragmentation, Degradation and Loss

37. Conservation in Fragmented Seascapes Protect and expand the amount of habitat Enhance the quality of the habitat Manage across the entire seascape Increase connectivity Plan for the long-term Learn from current and previous efforts