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Conservation Biology and Global Change Conservation biology = goal-oriented science that seeks to counter the biodiversity crisis, the current rapid decrease in Earth’s variety of life Extinction is a natural phenomenon that’s been occurring since life evolved on earth- the current rate of extinction is what underlies the biodiversity crisis- a high rate of species extinction is being caused by humans. Three levels of biodiversity:1. genetic diversity = genetic diversity within the gene pool of a species2. species diversity = types of different species within an ecosystem3. ecosystem diversity = community and ecosystem diversity across the landscape of an entire region Four major threats to biodiversity:1. habitat loss – human alteration of habitat is the single greatest threat to biodiversity2. introduced species – invasive/nonnative/exotic species3. overexploitation – harvest wild plants/animals4. global change - alter climate, atmosphere, and ecological systems à reduce Earth’s capacity to sustain life Landscape conservation: movement corridors – can promote dispersal if habitats are fragmented Biodiversity hotspots: unique habitats, islands, wetlands, coastal regions, reefs Eutrophication-excess nitrogen from agriculture enters aquatic ecosystems-algae and bacteria bloom/die à reduce oxygen à fish and invertebrates die Acid Precipitation-rain/snow/fog with a pH of less than 5.6-caused by burning fossil fuels à release sulfur oxides and nitrogen oxides-react with water in the atmosphere to produce sulfuric and nitric acids Biological Magnification-toxins become more concentrated in successive trophic levels of a food web-toxins can’t be broken down and magnify in concentration up the food chain ex: mercury in fish Human activities are depleting the atmospheric ozone-life on earth is protected from the damaging effects of UV radiation by a layer of O3-chlorine-containing compounds (CFCs) erode the ozone layer Greenhouse Effect-greenhouse effect: absorption of heat the earth experiences due to certain greenhouse gases-CO2 and water vapor absorb infrared radiation and re-reflect back toward earth-earth needs this heat, but too much could be disasterous Rising atmospheric O2-since the Industrial Revolution, the concentration of CO2 in the atmosphere has increased greatly as a result of burning fossil fuels Global Climate Change (Global Warming)-studies predict a doubling of CO2 in the atmosphere will cause a 3 degreeC increase in the average temperature on earth-rising temperatures could cause polar ice cap melting, which could flood coastal areas-snow and rainfall patterns shifting-floods, drought, intense rainfall, more frequent and severe heat waves, storms-approach: stabilize use of fossil fuels and reduce deforestation
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