Chapter 55: Conservation Biology & Restoration Ecology

1. Chapter 55: Conservation Biology & Restoration Ecology Conservation biology Integrates ecology, physiology, molecular biology, genetics, & evolution to conserve biodiversity Restoration ecology Sustain ecosystems & stop loss of biodiversity return conditions to original state through efforts from social sciences, economics, & humanities **The biodiversity crisis extinction is a natural phenomenon but the current rate of extinction is alarming and caused by one species…humans

2. Three levels of biodiversity • Genetic diversity • Microevolution occurs as a result of genetic variation • Organisms adapt to environments as a result of microevolution • Species diversity • Endangered species • Species in danger of extinction in all/significant portion of its range • Threatened species • Species likely to become endangered throughout all/most of its range • Extinction rates: • Can be as high as 50% in areas where 90% of habitat is lost • 12% of known birds are endangered • 24% of known mammals are endangered or threatened • 200 of 20,000 known plants are extinct • 20% of freshwater fish are/close to extinction • 32% of known amphibians are endangered ** to know if a certain species is extinct we must know its exact habitat & distribution

3. Ecosystem diversity • Habitat destruction leads to decrease in biodiversity Major threats to biodiversity • Habitat destruction • Human alteration of habitat through: • Logging • War • Oil spills • 93% of coral reefs damaged which support 1/3 of all known fish • Over-exploitation • Commercial fishing • Hunting • Collecting & trading exotic animals/products

4. Introduced species • Disrupt community by preying on native species & out-competing them for resources • Examples: zebra mussels, purple loose strife, Nile perch • According to IUCN 68% of endangered/extinction may be due to exotic species introduction Why conserve biodiversity? • Biophilia • Belief that all species are entitled to life • Crucial natural resource • Threatened species could provide crops, fibers, medicines • Humans are dependant on the ecosystem • We are part of the web of life • Estimates of replacing ecosystem service= $33 trillion/year

5. Population conservation • focuses on population size, genetic diversity, & critical habitat • Population viability analysis (PVA) • Examines chances a species has of surviving in its available habitats • Minimum viable population (MVP) • Minimum number of individuals required for a population to survive • Effective population size (Ne) • Based on the breeding potential of the population • Ne= (4Nm x Nf)/ (Nm + Nf) • Nm= number of males • Nf = number of females • Effects of genetic diversity on survivability • Low Ne prone to inbreeding, reduced heterozygosity & effects of genetic drift • Low Ne is normal for slow reproducing species (cheetah, grizzly bear) • Low genetic variability does not always lead to permanently small populations • Analyzing viability of selected species may help sustain other species **Conserving species involves weighing conflicting demands

6. Conservation at community, ecosystem, & landscape levels • Edges & corridors can strongly influence landscape diversity • Edges have their own communities of organisms that can have positive or negative effects on species in ecosystems bordering the corridor • Movement corridors connect isolated patches of habitat to discourage inbreeding & death of species • Nature preserves must be functional parts of the landscape • Must be well planned to be self regulating • 7% of world land is now reserve • Debate large reserves or several small reserves? • Costa Rica- leader in zoned reserves

7. Restoration ecology • Works to manipulate processes to reduce the time it takes for a community to bounce back after disturbances • Most environmental damage is reversible however communities are not infinitely resilient • Bioremediation • Make use of living organisms (prokaryotes, fungi, & plants) to detoxify a polluted ecosystem • Examples: bacterium cleaning up oil spills, plants collecting mining waste • Biological augmentation • Uses organisms to add essential materials to a degraded ecosystem

8. Sustainable development • Plan that provides for the long term prosperity of human society & the ecosystems that support them • Goals reorienting ecological research & changing some human values