310 likes | 531 Vues
Conservation. Chapter 6. Conserving Biodiversity. Population biology principles small populations of a species are more likely to become extinct than large populations easier to prevent “ endangered status ” than “ endangered ” to extinct
E N D
Conservation Chapter 6
Conserving Biodiversity Population biology principles • small populations of a species are more likely to become extinct than large populations • easier to prevent “endangered status” than “endangered” to extinct • to understand a population, important to consider age structure and sex ratio • populations must be monitored to determine the effects of a conservation plan on the status of a species
Conserving Biodiversity Conservation biology principles • species less likely to become extinct if broadly distributed across its range • habitat characteristics favoring species preservation: • large rather than small in size • close together rather than widely separated • whole rather than internally fragmented • linked by “corridors” rather than isolated • broad rather than long and narrow • inaccessible rather than easily accessible to people
Island Biogeography • What happens to species number as the island gets further away from source pool? • species # as distance of source pool • What happens to species number as the island gets smaller? • species # as surface area • study of facts and patterns of species distribution in/on islands • two important variables to consider • island’s distance from a source pool of species • surface area of an island
Island Biogeography • So, what would you predict in the Wisconsin forest example?
Size and Design of Nature Preserves • SLOSS debate - is it better to have single large or several small reserves? • Edge effects • Corridors of natural habitat essential
Parks and Nature Preserves • Theodore Roosevelt • president 1901-1909 • created: • game preserves • bird reservations • national monuments • 150 national forests • 5 national parks
U.S. Forest Service • Formed in 1907 by Gifford Pinchot • 155 National Forests; 20 national grasslands; 300,000 square miles • Department of Agriculture • Concerned with resource USE • The mission of the Forest Service is to sustain the health, diversity, and productivity of the Nation’s forests and grasslands to meet the needs of present and future
U.S. National Park Service • founded 1916 in Department of Interior • 401 units • 59 parks • others as monuments, historic sites, and recreation areas • 108,000 square miles • 300 million visitors each year
Canadian Park System Canada has a total of 1,471 parks and protected areas.
Park Problems • Development pressures at boundaries • Overcrowding and visitor demands for facilities • Pollution, noise, and environmental degradation due to motorized vehicles • Mining and oil interests
Wildlife Issues • Reintroduction of predators • Hunting • Increased human/ animal interaction • Manipulation of nature to provide a more enjoyable experience for visitors
Conservation and Economic Development • Immediate human survival always takes precedence over long-term environmental goals. • Ecotourism - a viable option ? • Indigenous peoples
emerging adult pupa mating adults larvae feed on milkweed larva egg on milkweed Monarch
Monarch Watch http://MonarchWatch.org Dr. Orley R. Taylor Jr. Professor of Biological Sciences University of Kansas
swarming in flight tagging Monarch Migration fall migration spring migration
Ecotourism and Monarch Butterflies Monarchs
Agriculture & Biodiversity • herbicide tolerant row crops • 1996 first introduced • gentically modified to resist glyphosate (Roundup) • known as Roundup Ready • 2004 – 51% of corn & soybeans were GM • 2010 – 81% • milkweeds now scare in row crop habitat
Wilderness Areas http://www.wilderness.net/index.cfm?fuse=NWPS
Arguments for: refuge for endangered wildlife opportunity for solitude and primitive recreation baseline for ecological research Arguments against: natural resources locked up decreased access for motorized recreation traditional ways of life threatened Do we need more wilderness? • For many people, especially those in developing countries, the idea of having pristine wilderness is not very important.
Wildlife Refuges • Troubled system for wildlife preservation in U.S. • Approximately 1% of U.S. surface area • About 60% of all refuges allow activities that are harmful to wildlife. • More than 75% of U.S. refuges have water pollution problems. • ARCTIC NATIONAL WILDLIFE REFUGE STAYS WILD • DEFENDERS OF WILDLIFE DECLARES VICTORY • Dec 21, 2005 • Senate Vote Stops Pro-Drilling Forces • Washington, DC - Defenders of Wildlife hailed today's vote to block language from the Defense Appropriations bill that would have authorized oil and gas drilling in the Arctic National Wildlife Refuge, calling it one of the most significant conservation victories in recent years.
Parks as Ecosystems • Park boundaries usually based on political rather than ecological considerations • Biogeographical area important • International Union for the Conservation of Nature and Natural Resources (IUCN) categories
p. 140 (International Union of Conservation of Nature and Natural Resources )
p. 141 (International Union of Conservation of Natural Resources )