Transcript Chapter 55: Conservation Biology & Restoration Ecology

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
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Microevolution occurs as a result of genetic variation
Organisms adapt to environments as a result of
microevolution
Species diversity
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Endangered species
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Threatened species
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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
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Ecosystem diversity
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Habitat destruction leads to decrease in biodiversity
Major threats to biodiversity
 Habitat destruction
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Human alteration of habitat through:
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Logging
War
Oil spills
93% of coral reefs damaged which support 1/3 of all known
fish
Over-exploitation
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Commercial fishing
Hunting
Collecting & trading exotic animals/products
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Introduced species
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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
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Crucial natural resource
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Belief that all species are entitled to life
Threatened species could provide crops, fibers, medicines
Humans are dependant on the ecosystem
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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)
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Examines chances a species has of surviving in its available habitats
Minimum viable population (MVP)
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Effective population size (Ne)
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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
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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
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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
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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
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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
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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