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NATIONAL PARKS. Countries have established more than 1,100 national parks, but most are threatened by human activities. Local people invade park for wood, cropland, and other natural resources. Loggers, miners, and wildlife poachers also deplete natural resources.
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NATIONAL PARKS • Countries have established more than 1,100 national parks, but most are threatened by human activities. • Local people invade park for wood, cropland, and other natural resources. • Loggers, miners, and wildlife poachers also deplete natural resources. • Many are too small to sustain large-animal species. • Many suffer from invasive species.
Parks and Preserves • Park- an area set aside for use by people • Nature preserve- may be use by people but primary purpose the conservation of some resource • Both create ecological islands • Island biogeography used in design and management
Parks and Preserves as Islands • The size of the park and the diversity of habitats determine the # of species that can be maintained. • The further the park is from other parks or sources of species, the fewer species are found.
Solutions National Parks • Integrate plans for managing parks and nearby federal lands • Add new parkland near threatened parks • Buy private land inside parks • Locate visitor parking outside parks and use shuttle buses for entering and touring heavily used parks • Increase funds for park maintenance and repairs • Survey wildlife in parks • Raise entry fees for visitors and use funds for park management and maintenance • Limit the number of visitors to crowded park areas • Increase the number and pay of park rangers • Encourage volunteers to give visitor lectures and tours • Seek private donations for park maintenance and repairs Fig. 10-24, p. 211
Case Study: Stresses on U.S. National Parks • Overused due to popularity. • Inholdings (private ownership) within parks threaten natural resources. • Air pollution. Figure 10-23
NATURE RESERVES • Ecologists call for protecting more land to help sustain biodiversity, but powerful economic and political interests oppose doing this. • Currently 12% of earth’s land area is protected. • Only 5% is strictly protected from harmful human activities. • Conservation biologists call for full protection of at least 20% of earth’s land area representing multiple examples of all biomes.
NATURE RESERVES • Large and medium-sized reserves with buffer zones help protect biodiversity and can be connected by corridors. • Costa Rica has consolidated its parks and reserves into 8 megareserves designed to sustain 80% if its biodiversity. Figure 10-10B
Guanacaste Caribbean Sea Nigaragua Llanuras de Tortuguero Costa Rica La Amistad Arenal Bajo Tempisque Panama Cordillera Volcanica Central Pacifico Central Peninsula Osa Pacific Ocean Fig. 10-B, p. 213
34 hotspots identified by ecologists as important and endangered centers of biodiversity. Figure 10-26
Wildlife and Endangered Species • Common history of exploitation, management and conservation • When saving a species, what is it we really want to save? • 1. A wild creature in a wild habitat, as a symbol to us of wilderness. • 2. A wild creature in a managed habitat. • 3. A population in a zoo. • 4. Genetic material only.
Wildlifeand Endangered Species • Involves science and values • Many reasons for wishing to save endangered species. • Policies and actions differ widely depending on goal chosen.
SPECIES EXTINCTION • Scientists use measurements and models to estimate extinction rates. • The International Union for the Conservation of Nature and Natural Resources (IUCN) publishes an annual Red List, listing the world’s threatened species. • The 2004 Red List contains 15,589 species at risk for extinction. Figure 11-5
The Current Status of Endangered Species • The # of species listed as threatened or endangered increasing • The Red List • 20% of all know mammals at risk • 31% of amphibians • 3% of fish • 12.5% of plants recently extinct or endangered
The Current Status of Endangered Species • The term endangered species as defined by the ESA • “Any species which is in danger of extinction throughout all or a significant portion of its range…” • With the exception of insect pests • The term threatened species • “Means any species which is likely to become an endangered species w/in the foreseeable future throughout all or a significant portion of its range.”
Case Study: The U.S. Endangered Species Act • Biodiversity hotspots in relation to the largest concentrations of rare and potentially endangered species in the U.S. Figure 11-18
Top Six Hot Spots 1 Hawaii 2 San Francisco Bay area 3 Southern Appalachians 4 Death Valley 5 Southern California 6 Florida Panhandle Concentration of rare species Moderate Low High Fig. 11-18, p. 241
Endangered Species History of Extinctions • Extinctions have existed long before humans had an influence However:
The current extinction crisis is the first to be caused by a single species- US! . This is happening faster than ever; a few decades versus thousands to millions of years.Humans are eliminating not only the species but, the environment. Ex. Tropical rainforest
VOCABULARY: Extinct-Complete disappearance of a species from the earth.Ex: Dinosaurs
SPECIES EXTINCTION • Species can become extinct: • Locally: A species is no longer found in an area it once inhabited but is still found elsewhere in the world. • Ecologically: Occurs when so few members of a species are left they no longer play its ecological role. • Globally (biologically): Species is no longer found on the earth.
Global Extinction • Some animals have become prematurely extinct because of human activities. Figure 11-2
Florida manatee Kirkland’s warbler Grizzly bear Knowlton cactus African elephant Swallowtail butterfly Humpback chub Utah prairie dog Siberian tiger Golden lion tamarin Fig. 11-3, p. 224
Giant panda Blue whale Whooping crane Northern spotted owl Black-footed ferret Mountain gorilla Florida panther California condor Hawksbill sea turtle Black rhinoceros Fig. 11-3, p. 224
SPECIES EXTINCTION • Some species have characteristics that make them vulnerable to ecological and biological extinction. • Low Reproductive Rate • Specialized Feeding Habits • Feed at high trophic levels • Large size • Specialized nesting or breeding areas • Found only in one place or region • Fixed migratory patterns • Preys on livestock or people • Behavioral Patterns
How a Species Becomes Endangered and Extinct • Rate of extinctions has varied over geologic time • From 580 million years ago until industrial revolution about one species per year • Rate of evolution of new species =or > the rate of extinction • Average longevity of a species 10 million years • Other periods of “punctuated extinctions”
How People Cause Extinctions and Affect Biological Diversity • By hunting or harvesting. • By disrupting or eliminating habitats. • By introducing exotic species. • By creating pollution.
Good News • Species whose status has improved • Elephant seal • Sea otter • Many bird species effects by DDT, including bald eagle, brown pelican, white pelican, osprey and peregrine falcon. • Blue whale • Gray whale
Can a Species be too Abundant? • Sea lions now number 50,000 and have become a problem in S.F. and S.B. Harbors • Mountain lions in California • Both mountain lion and human population growing • People building in lion habitat • Attacks more common