Transcript AP Biology
Chapter 55 Conservation Biology and Restoration Ecology I. Humans Threaten Biodiversity Three levels of Biodiversity – Genetic – Species – Ecosystem Major Threats – Habitat destruction – Introduced species – Overexploitation – Disruption of Interaction Networks LE 55-2 Genetic diversity in a vole population Species diversity in a coastal redwood ecosystem Community and ecosystem diversity across the landscape of an entire region Figure 55-05 LE 55-6 Brown tree snake, introduced to Guam in cargo. Introduced kudzu thriving in South Carolina Figure 55-08 II. Population Conservation Small population approach – Extinction vortex – Minimum Viable Population size – Effective Population size Declining-Population Approach LE 55-9 Small population Inbreeding Genetic drift Lower reproduction Higher mortality Loss of genetic variability Reduction in individual fitness and population adaptability Smaller population LE 55-10 Number of male birds 200 150 100 50 0 1970 1975 1980 1985 Year 1990 1995 2000 Population dynamics Eggs hatched (%) 100 90 80 70 60 50 40 30 1970–74 1975–79 1980–84 1985–89 Years Hatching rate 1990 1993–97 Figure 55-11 LE 55-12 150 Females with cubs Number of individuals Cubs 100 50 0 1973 1982 1991 Year 2000 LE 55-13 A red-cockaded woodpecker perches at the entrance to its nest site in a longleaf pine. Forest that can sustain redcockaded woodpeckers has low undergrowth. Forest that cannot sustain red-cockaded woodpeckers has high, dense undergrowth that impacts the woodpeckers’ access to feeding grounds. III. Sustaining Biotas Landscape Structure – Fragmentation, edges and corridors Protected Areas – Actual evapotranspiration LE 55-14 Natural edges. Grasslands give way to forest ecosystems in Yellowstone National Park. Edges created by human activity. Pronounced edges (roads) surround clear-cuts in this photograph of a heavily logged rain forest in Malaysia. Figure 55-15 Figure 55-16 LE 55-17 Terrestrial biodiversity hot spots Equator LE 55-18 0 50 100 Kilometers 43° Montana Wyoming 42° Yellowstone National Park Montana Idaho 41° Grand Teton National Park Wyoming Idaho 40° LE 55-21 104 Natural disasters Human-caused disasters Natural OR humancaused disasters 1,000 Meteor strike Industrial pollution Groundwater exploitation Urbanization Salination Modern Volcanic Acid eruption rain Flood agriculture 100 Slash & burn Forest Nuclear Tsunami bomb Oil fire spill Landslide 10 Tree fall Lightning strike 1 10–3 10–2 10–1 1 10 Spatial scale (km2) (log scale) 100 1,000 104 IV. Restoration Ecology Bioremediation Biological augmentation Sustainability