unit 6: biodiversity environmental science 1. biodiversity 16 june 2010biodiversity.ppt2 variety of...
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Unit 6:Biodiversity
Environmental Science
1
Biodiversity
16 June 2010 Biodiversity.ppt 2
• Variety of living things, number of kinds
3 Components of BD:• 1. Ecological diversity
– different habitats, niches, species interactions
• 2. Species diversity– different kinds of organisms,
relationships among species• 3. Genetic diversity
– different genes & combinations of genes within populations
Benefits of Biodiversity
• Ecosystem functions• Ecosystem services
• Cleaning water,
• Cleaning air,
• Habitat & breeding areas for wildlife, …
• Aesthetic and cultural benefits
16 June 2010 Biodiversity.ppt 3
Natural Resources
• Vital economic natural resources– Renewable• Forests (plants, wildlife)
• Soils
• Fresh water (lakes, rivers)
• Wildlife and fisheries
• Rangeland
– Nonrenewable• Minerals
• Fossil Fuels
16 June 2010 Biodiversity.ppt 4
Natural Resources
• Management of natural resources– Assure availability of
resources for the future
– Three “philosophies”• Maximum sustained yield
• Ecosystem-based management
• Adaptive management
16 June 2010 Biodiversity.ppt 5
Benefits of Biodiversity• New food sources
– Grains, fruits, vegetables, meat, fish
16 June 2010 Biodiversity.ppt 6
Benefits of Biodiversity
• Medicines• Plants
• Jellyfish & sea anemones
• Nudibranchs • Marine slugs
16 June 2010 Biodiversity.ppt 7
Biodiversity• How much biodiversity
1.7—2.0 million speciesEstimates to 100 million
16 June 2010 Biodiversity.ppt 8
Biodiversity
16 June 2010 Biodiversity.ppt 9
• 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
Threats to Biodiversity
• Extinction and population reductions– Hunting and overharvesting
• Tiger
• Dodo
• Whales
• Sharks
– Habitat loss
16 June 2010 Biodiversity.ppt 10
Threats to Biodiversity
• Extinction and population reductions– Pollution
– Climate change
– Invasive species
16 June 2010 Biodiversity.ppt 11
Protecting Biodiversity
16 June 2010 Biodiversity.ppt 12
• 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
Protecting Biodiversity
• Refuges, parks, preserves– How big should refuges be?
–Where should they be?
–McArthur & Wilson “Theory of Island Biogeography”• colonization rate
• extinction rate (local)
• predicts number of species
16 June 2010 Biodiversity.ppt 13
Protecting Biodiversity
16 June 2010 Biodiversity.ppt 14
• Island Biogeography– Island size predicts number of species
Protecting Biodiversity
16 June 2010 Biodiversity.ppt 15
• Island Biogeography– Everyplace is an island
– Habitat fragmentation• Smaller fragments hold
fewer species
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:– Marine Mammal Protection Act
– Migratory Bird Treaty Act
– Anadromous Fish Conservation Act
– etc.
16 June 2010 Biodiversity.ppt 16
Protecting Biodiversity
16 June 2010 Biodiversity.ppt 17
• 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.
• http://www.fws.gov/endangered/
Protecting Biodiversity
16 June 2010 Biodiversity.ppt 18
• Biodiversity “hotspots”– Protection of habitat