330 likes | 727 Views
Biodiversity and Its Decline. The decline in biodiversity Reasons for the decline Consequences of losing biodiversity. Reasons for Biodiversity Decline. Habitat change Conversions Fragmentation Simplification Intrusion Exotic (invasive) species introductions.
E N D
Biodiversity and Its Decline The decline in biodiversity Reasons for the decline Consequences of losing biodiversity
Reasons for Biodiversity Decline Habitat change Conversions Fragmentation Simplification Intrusion Exotic (invasive) species introductions
Reasons for Biodiversity Decline Overexploitation: combination of greed, ignorance, and desperation Pollution Climate change
Habitat Alterations Photo by C.E. Adams
Pollution: Exxon Valdez Oil Spill March 24, 1989 11 million gallons of crude oil spilled into Prince William Sound Oil slick
Exotic Species Brown tree snake
Deliberately Introduced Species • Include domestic animals and crops • Biotic pollution • Many deliberately introduced species have had unintended disasterous effects • Wipe out native species due dominance • Non-native species threaten more than half of the endangered species in U.S. and 95% of those endangered in Hawaii.
Accidently Introduced Invasive Species • Millennium Ecosystem Assessment calls this the downside of globalization • Fire ants • Fomosan termites • Zebra mussels • Burmese python • Comb jellyfish
Successful Invasive Species • High reproductive rate (r-selected) • Pioneer species • High genetic variability (easily adaptable) • High dispersal rate • Long lived
Ecosystems Vulnerable to Invasive Species • Climate similar to habitat of invader • Absence of predator of invasive species • Early successional system • Low biodiversity • Absence of fire • Human disturbance of habitat
Invasive Prevention • Do not bring in plants, soil, aquatic animals, fruit, meats or fresh or salt water from other regions or countries • Do not dump bait or aquariums into local surface waters • Use common sense
Overuse Harvest of 50 million song birds for food
Overuse Trafficking in wildlife and products derived from wild species - $12 billion/year 90% decline in rhinos 1.6 tons of tiger bones = 340 tigers Parrot smuggling: 40 of 330 species face extinction
Biodiversity Hotspots 60% of the biodiversity is located on just 1.4% of the Earth’s land surface.
Protecting Biodiversity International developments Stewardship concerns
Past Wildlife Management Problems Restoring the numbers of many game animals, e.g., deer, elk, turkey. Passing laws to control the collection and commercial exploitation of wildlife. Poaching and over-hunting.
Contemporary Wildlife Management Problems Road-killed animals Population explosion of urban wildlife Lack of natural predators Wildlife as vectors for certain diseases Pet predation by coyotes Changed societal attitudes towards animals
International Steps to Protect Biodiversity “Red List of Threatened Species” 11,167 species of plant and animals Convention on trade in endangered species (CITES) Focuses on trade in wildlife and wildlife parts Convention of Biological Diversity (CBD)
International Steps to Protect Biodiversity Convention of Biological Diversity (CBD) Stepping up war on invasive species Access to genetic resources Stem tide of deforestations Formulating a strategic plan through 2010
International Steps to Protect Biodiversity Convention on biological diversity Focuses on conserving biological diversity worldwide Does not yet have the support of the United States
Critical Ecosystem Partnership Fund Sponsors: World Bank, Conservation International, and the Global Environment Facility Fund = $150 million for developing countries Protect biodiversity “hotspots”
Acts Protecting Endangered Species Lacey Act: forbids interstate commerce of illegally killed wildlife Endangered Species Act (ESA): protects endangered and threatened species (Table 10-3) Total endangered U.S. species = 1,001 (402 animals, 599 plants) Threatened U.S. species = 300 (154 animals, 146 plants)
Strengths or Weaknesses of Endangered Species Act? The need for official recognition Control over commercial exploitation of endangered species Government controls on development in critical habitats Recovery programs Habitat conservation plan (HCP)
Stewardship Concerns Managing and protecting something you DO NOT own. Involves: Wisdom Values
The Wisdom of Stewardship Reforming policies that lead to declines in biodiversity Addressing the needs of people whose livelihood is derived from exploiting wild species
The Wisdom of Stewardship Practicing conservation at the landscape level Promoting more research on biodiversity
The Values of Stewardship Manage or mine the resource? Human perceptions of their relationships to the natural world. Deep ecology: we are part of the Earth and not separate from it Religious faiths