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Ch. 55Conservation Ecology
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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
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Three levels of biodiversity:
1. Genetic diversityindividual variation as well as between populations
2. Species diversity variety of species in an ecosystemU.S. Endangered Species Act (1973)
a. endangered "in danger of extinction throughout all or a significant portion of its range"
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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)
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Endangered speciesPhilippine Eagle
Chinese River Dolphin
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3. Ecosystem diversityex. 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!)
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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
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6. risk our own survivalpurification of water/airnutrient cyclingdetoxification and decomposition of wastescontrol agricultural pests
rosy periwinkle used for Hodgkin's disease and acutelymphocytic leukemia
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Biosphere II in Arizona 1990, 8 people put inside, had many different ecosystems, supposed to be self sufficientlasted 15 months
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What are the threats to biodiversity?1. Habitat loss = greatest threata. Habitat destruction
due to agriculture, forestry, mining, pollution, urban development, coral reef destruction
b. Habitat fragmentationecosystems that are broken into smaller pieces
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habitat reductionand fragmentationin a Wisconsin forestover time
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2. Introduced Species = nonnative or exotic speciesthose 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
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Zebra musselsappeared in the Great Lakes in 1988
thought to be brought via ballast in ships from Europe
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Nile Perch Brown Tree Snake
Argentine Ants Seaweed Caulerpa
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3. Overexploitationhumans harvesting wild plants or animals at rates higher than can be replaced reproductivelyEx. elephants, whales, rhinoceroses
hurts animals native to islandsoverfishing trawling
the great auk found in North Atlantic Ocean islands
White rhinoceros killed for its horn
http://www.nwf.org/Wildlife/WildlifeConservation/ThreatstoWildlife/Overexploitation.aspx
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Population Conservation approaches1. small population approach study processes that cause very small populations to become extinct
extinction vortex (downward spiral) loss of genetic variation
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minimum viable population size the minimum population size that species are able to maintain their numbers and survive
usually computer generatedused 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
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Populations with low Ne prone to:
inbreedingreduced heterozygosityrandom effects of genetic drift/bottlenecking
Ex. Prairie chickenfragmented habitat Illinois chicken decreased
hatching rate headed for extinction vortex until humans introduced chickens from Nebraska, then rates went up
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in 1992scientists introduced prairie chickens from Minnesota, Kansas, andNebraska
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Grizzly Bear in Yellowstone National Park
monitoring population by tagging the bears with a radio collar to track movements
males
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2. Decliningpopulation approach focuses on threatened and endangered species
emphasizes environmental factors that cause population decline
evaluated on a case by case basis
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Steps for decling population approach:
1. confirm species is in decline look at population trends2. study species natural history to determine environmental
requirements3. determine all possible causes of decline4. list hypothesis predictions of decline5. test hypothesis6. apply results to help manage species
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Red cockaded woodpeckerforest that sustains woodpecker lowundergrowth
forest that cannot sustain woodpecker high undergrowth
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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
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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 environmentsedges have different characteristics than either of the environments on either sidewhitetailed deer, ruff grouse live in these edgescan have positive or negative effect on community biodiversity
negative = cowbirdpositive = area of speciation
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natural edges human created edges
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use of movement corridors = strip of land or a bridge connecting two isolated areas of inhabitable land
Ex. Florida panthersimportant for migrating speciescan also spread disease of population
artificial corridor for Florida panthers
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How do Conservation biologists attempt to maintainbiodiversity?
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
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Biodiversity Hot Spots
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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
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biotic boundary for shortterm survival of 50 individuals
biotic boundary for longterm survival of 500 bears
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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
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Ex. Costa Rica
green =national parks
gold =buffer zones
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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
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salmoncolored= natural
white = human caused
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two strategies for restoration ecology:
1. bioremediation using organisms to detoxify polluted areas
ex. plants for uptake of toxic metals from miningPseudomonas for oil spills
2. augmentation use of organisms to add materials to degraded ecosystem
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Ex. legumes to add nitrogen to soil
Albizzia procera lives in nitrogen poor soil and allows indigenous to recolonize
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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 changes2. biological diversity3. productivity methods of natural and artificial ecosystems
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Future of the biosphere depends on our biophilia
biophiliaour innate sense of love of nature and our connection to other organisms
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• 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
Review You should be able to:
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• 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
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