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SUSTAINING WILD SPECIES Species Conservation
Factors affecting Biodiversity • Increases biodiversity: • Physically diverse habitat • Moderate environmental disturbance • Small variations in environmental conditions • Middle stages of succession • Evolution • Decreases biodiversity: • Environmental stress • Large environmental disturbance • Extreme environmental conditions • Severe limitations of resources • Introduction of exotics • Habitat loss
• How have human activities affected global biodiversity? • • • Taken over or degraded 40 -50% of earth’s surface Waste or destroy 27% of total net primary productivity Losing our wetlands and deforestation Coral reefs Threatening many organisms with premature extinction
BIODIVERSITY HOT SPOTS
Goals for reducing loss of biodiversity: • To prevent premature extinction of species • To preserve and restore ecosystems and aquatic systems that provide habitats and resources for species.
HOW DO BIOLOGISTS EXTIMATE EXTINCTION RATES?
HOW DO BIOLOGISTS EXTIMATE EXTINCTION RATES? SPECIES -AREA RELATIONSHIP Scientists observe: • # species increases with area • assume that an average of 90% loss of habitat causes the extinction of about 50% of the species living in that habitat • but destruction of 10% of the habitat can wipe out all of the remaining species if they cannot move!
CHARACTERISTICS OF SPECIES THAT ARE PRONE TO EXTINCTION:
What can be done about invasive species? • Identify characteristics of successful invaders • Do better inspections • Identify invader species and pass laws • Require ships to discharge ballast waters in the ocean not in port
ROLE OF LOSS OF GENETIC DIVERSITY • LIMITS ABILITY TO SURVIVE • HOW LOST: • FOUNDER EFFECT - SUCH A SMALL NUMBER OF INDIVIDUALS THEY CANNOT SUSTAIN THE POPULATION • INBREEDING • DEMOGRAPHIC BOTTLENECK - TOO FEW INDIVIDUALS TO PERPETUATE POPULATION • GENETIC DRIFT - UNEQUAL REPRODUCTIVE SUCCESS -SOME INDIVIDUALS BREED AND DOMINATE THE GENE POOL
Protecting Wild Species LAWS AND TREATIES
INTERNATIONAL TREATIES • CITES - CONVENTION ON INTERNATIONAL TRADE IN ENDANGERED SPECIES - 1975 • 152 countries • 800 species can not be commercially traded live or as products • 29, 000 species monitored and regulated because they are threatened • limited enforcement • small fines • much goes on in countries who did not sign • CONVENTION OF BIOLOGICAL DIVERSITY (CBD) • 172 countries - not U. S. • help protect global biodiversity • very comprehensive treaty
NATIONAL LAWS • LACEY ACT - 1900 - prohibits transporting live or dead wildlife products across state borders without a federal permit • ENDANGERED SPECIES ACT (ESA) 1975 - cannot import or trade in any product from endangered or threatened species except for scientific purposes • must be on the list • must have a plan for recovery
WHAT ELSE CAN BE DONE? • ENCOURAGE PRIVATE LANDOWNERS • habitat conservation plans • safe harbor agreements - restore habitats • candidate conservation agreements • WILDLIFE REFUGES - MOST ARE WETLANDS • GENE BANKS, BOTANICAL GARDENS AND FARMS • seed banks • kew gardens
IMPORTANCE OF ZOOS • USE TWO TECHNIQUES: • egg pulling - collect eggs and hatch in zoos • captive breeding reintroduce into the wild • artificial insemination • embryo transfer • incubators • cross fostering with similar species • use databases to match individuals for mating
WILDLIFE MANAGEMENT • MANIPULATING WILDLIFE POPULATIONS (ESPECIALLY GAME ANIMALS) AND THEIR HABITATS FOR THEIR WELFARE AND HUMAN BENEFITS • hunting regulations • harvest quotas • population management plans • improving habitats • using international treaties to protect migrating game species