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 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 Threatened species Species in danger of extinction in all/significant portion of its range 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 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 Introduced species Disrupt community by preying on native species & outcompeting 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 Crucial natural resource Belief that all species are entitled to life 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 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) Effective population size (Ne) Minimum number of individuals required for a population to survive 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 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 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 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