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Biodiversity
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Biodiversity
• Variety of living things,
number of kinds
• Ecological diversity
– different habitats, niches,
species interactions
• Species diversity
– different kinds of
organisms, relationships
among species
• Genetic diversity
– different genes &
combinations of genes
within populations
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Benefits of Biodiversity
• Ecosystem functions
• Ecosystem services
• Cleaning water,
• Cleaning air,
• Habitat & breeding
areas for wildlife, …
• Aesthetic and
cultural benefits
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Natural Resources
• Vital economic natural resources
– Renewable
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Forests (plants, wildlife)
Soils
Fresh water (lakes, rivers)
Wildlife and fisheries
Rangeland
– Nonrenewable
• Minerals
• Fossil Fuels
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Natural Resources
• Management of natural
resources
– Assure availability of
resources for the future
– Three “philosophies”
• Maximum sustained yield
• Ecosystem-based
management
• Adaptive management
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Benefits of Biodiversity
• New food sources
– Grains, fruits, vegetables, meat, fish
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Benefits of Biodiversity
• Medicines
• Plants
• Jellyfish & sea
anemones
• Nudibranchs
• Marine slugs
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Biodiversity
• How much biodiversity
 1.7—2.0 million species
 Estimates to 100 million
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Biodiversity
• Where is the biodiversity
– Everywhere
• Every continent and habitat
has unique life forms
– Concentrated in the
tropics
• Panama: > 500 species of
breeding birds
• Arctic: 50-100 species
– Dense concentrations
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Threats to Biodiversity
• Extinction and population
reductions
– Hunting and overharvesting
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Tiger
Dodo
Whales
Sharks
– Habitat loss
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Threats to Biodiversity
• Extinction and
population reductions
– Pollution
– Climate change
– Invasive species
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Protecting Biodiversity
• How can we protect
biodiversity
– Stop overharvesting
• Sustainable yield
• Hunting & fishing laws
(every state ?)
– in developing nations ?
– Protect habitat
• Refuges, parks, preserves
– Endangered Species Act
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Protecting Biodiversity
• Refuges, parks, reserves
– How big should refuges be?
– Where should they be?
– McArthur & Wilson “Theory of Island
Biogeography”
• colonization rate
• extinction rate (local)
• predicts number of species
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Protecting Biodiversity
• Endangered Species Act (1973)
– Goal to “recover” species so they no longer need protection under ESA
– Implements U.S. participation in CITES
• “Convention on International Trade in Endangered Species”
• Prohibits trade in listed species
– whole organisms
– parts: skins, bones, teeth, flowers, leaves, etc.
• Other laws:
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Marine Mammal Protection Act
Migratory Bird Treaty Act
Anadromous Fish Conservation Act
etc.
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Protecting Biodiversity
• Endangered Species Act
(1973)
– Listing of “endangered” and
“threatened” species
– Restricts development of
habitats
– Captive breeding programs
• Release of captive bred
stocks to enhance or
recover wild populations.
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Protecting Biodiversity
• Biodiversity “hotspots”
– Protection of habitat
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