Ch. 55 Conservation Ecology
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Ch. 55 Conservation Ecology 1 Conservation ecology is an effort to save biodiversity loss Restoration ecology ecological principles to return ecosystems that have been disturbed by human acitivity to a condition as similar as possible to their original natural state 2 Three levels of biodiversity: 1. Genetic diversity individual variation as well as between populations 2. Species diversity variety of species in an ecosystem U.S. Endangered Species Act (1973) a. endangered "in danger of extinction throughout all or a significant portion of its range" 3 b. threatened organisms that are likely to become endangered in the future c. extinction population does not exist anymore either locally or globally ex. 1,183 bird species (13% in world) 4 Endangered species Philippine Chinese River Dolphin Eagle 5 3. Ecosystem diversity ex. rainforests loss of keystone predator (sea star/mussel scenario) extinction of one organism has a great impact on other organisms in the excosystem (think food webs!) 6 Why do we want to preserve biodiversity? 1. natural resources for medicines, fibers, crops, etc. 2. to prevent loss of genes which code for useful proteins 3. potential for future development of new medicines, foods, petroleum substitutes, chemicals 4. aesthetic reasons 5. ethical reasons 7 6. risk our own survival purification of water/air nutrient cycling detoxification and decomposition of wastes control agricultural pests rosy periwinkle used for Hodgkin's disease and acute lymphocytic leukemia 8 Biosphere II in Arizona 1990, 8 people put inside, had many different ecosystems, supposed to be self sufficient lasted 15 months 9 What are the threats to biodiversity? 1. Habitat loss = greatest threat a. Habitat destruction due to agriculture, forestry, mining, pollution, urban development, coral reef destruction b. Habitat fragmentation ecosystems that are broken into smaller pieces 10 habitat reduction and fragmentation in a Wisconsin forest over time 11 2. Introduced Species = nonnative or exotic species those that humans move from the species' native location to a new geographic location ( accidentally or on purpose) Ex. zebra mussels, African bees, brown tree snake in Guam, fox in Australia, purple loosestrife, milfoil 12 Zebra mussels appeared in the Great Lakes in 1988 thought to be brought via ballast in ships from Europe 13 Nile Perch Brown Tree Snake Argentine Ants Seaweed Caulerpa 14 3. Overexploitation humans harvesting wild plants or animals at rates higher than can be replaced reproductively Ex. elephants, whales, rhinoceroses hurts animals native to islands overfishing trawling White rhinoceros killed for its horn http://www.nwf.org/Wildlife/WildlifeConservation/ThreatstoWildlife/Overexploitation.aspx the great auk found in North Atlantic Ocean islands 15 Population Conservation approaches 1. small population approach study processes that cause very small populations to become extinct extinction vortex (downward spiral) loss of genetic variation 16 minimum viable population size the minimum population size that species are able to maintain their numbers and survive usually computer generated used in part of population viability analysis (predicts species survival) effective population size (Ne) based on breeding potential Ne = 4Nf Nm Nf = number of breeding females Nf + Nm Nm = number of breeding males 17 Populations with low Ne prone to: inbreeding reduced heterozygosity random effects of genetic drift/bottlenecking Ex. Prairie chicken fragmented habitat Illinois chicken decreased hatching rate headed for extinction vortex until humans introduced chickens from Nebraska, then rates went up 18 in 1992 scientists introduced prairie chickens from Minnesota, Kansas, and Nebraska 19 Grizzly Bear in Yellowstone National Park monitoring males population by tagging the bears with a radio collar to track movements 20 2. Decliningpopulation approach focuses on threatened and endangered species emphasizes environmental factors that cause population decline evaluated on a case by case basis 21 Steps for decling population approach: 1. confirm species is in decline look at population trends 2. study species natural history to determine environmental requirements 3. determine all possible causes of decline 4. list hypothesis predictions of decline 5. test hypothesis 6. apply results to help manage species 22 Red cockaded woodpecker forest that sustains woodpecker low undergrowth forest that cannot sustain woodpecker high undergrowth 23 Conflicts of conservation biology environment vs. demands for jobs in timber, mining environment vs. economics can't save all organisms, which should we save?? look at individual or whole community 24 Conservation focus is on communities Landscape ecology application of ecological principles to the study of human land use patterns organisms can live on edges of two different environments edges have different characteristics than either of the environments on either side whitetailed deer, ruff grouse live in these edges can have positive or negative effect on community biodiversity negative = cowbird positive = area of speciation 25 natural edges human created edges 26 use of movement corridors = strip of land or a bridge connecting two isolated areas of inhabitable land Ex. Florida panthers important for migrating species can also spread disease of population artificial corridor for Florida panthers 27 How do Conservation biologists attempt to maintain biodiversity? 1. National Parks protected 2. protecting biodiversity hot spotssmall areas with high concentrations of endemic species and a large # of endangered or threatened species contain 1/3 of all species of plants and vertebrates 28 Biodiversity Hot Spots 29 Actual area needed by an organism may be larger than the actual protected area biotic boundary = area needed to sustain a certain population size legal boundary = the actual area of protected area 30 biotic boundary for shortterm survival of 50 individuals biotic boundary for longterm survival of 500 bears 31 3. Nature reserves biodiversity "islands" in an area degraded by human activity zoned reserve a large region of land that includes one or more areas undisturbed by humans surrounded by lands that have been changed by human activity and are used for economic gain surrounding land acts as a buffer zone from intrusion 32 Ex. Costa Rica green = national parks gold = buffer zones 33 4. Restoration ecologyreturning degraded ecosystems to as close to natural conditions as possible assume most damage is reversible based on succession principles larger area disturbed, longer it takes to recuperate 34 salmoncolored= natural white = human caused 35 two strategies for restoration ecology: 1. bioremediation using organisms to detoxify polluted areas ex. plants for uptake of toxic metals from mining Pseudomonas for oil spills 2. augmentation use of organisms to add materials to degraded ecosystem 36 Ex. legumes to add nitrogen to soil Albizzia procera lives in nitrogen poor soil and allows indigenous to recolonize 37 Sustainable Biosphere Initiative goal: "define and acquire ecological information necessary for the intelligent and responsible development, management and conservation of Earth's resources" Studies: 1. global changes 2. biological diversity 3. productivity methods of natural and artificial ecosystems 38 Future of the biosphere depends on our biophilia biophiliaour innate sense of love of nature and our connection to other organisms 39 Review You should be able to: • Distinguish between conservation biology and restoration biology • List the three major threats to biodiversity and give an example of each • Define and compare the smallpopulation approach and the declining population approach • Distinguish between the total population size and the effective population size • Describe the conflicting demands that may accompany species conservation 40 • Define biodiversity hot spots and explain why they are important • Define zoned reserves and explain why they are important • Explain the importance of bioremediation and biological augmentation of ecosystem processes in restoration efforts • Describe the concept of sustainable development • Explain the goals of the Sustainable Biosphere Initiative 41 42.