Unformatted text preview: Sustaining Biodiversity: The Species Approach Chapter 9 Importance of Wild Species May take nature 5 million years to replace the species that may be lost in the 21st century Instrumental value Genetic information Recreational pleasure and ecotourism Intrinsic or existence value Even small organisms can be important Nature's Pharmacy Fig. 9-6, p. 189 Causes of Premature Extinction "HIPPO" Habitat destruction and fragmentation Invasive (alien) species Population growth (humans) Pollution Overharvesting Causes of Premature Extinction Habitat loss Overfishing Climate change Predator and pest control Pollution Commercial hunting and poaching Sale of exotic pets and decorative plants Habitat degradation and fragmentation Introducing nonnative species Secondary Causes Population growth Rising resource use No environmental accounting Poverty Basic Causes Fig. 9-7, p. 190 Extinction Threats from Habitat Loss and Degradation Importance of habitats Deforestation Destruction of wetlands and coral reefs Endemic species "Habitat islands" Habitat fragmentation "Message" from the birds Environmental indicators Reduced Ranges Indian Tiger Range 100 years ago Range today (about 2,300 left) Fig. 9-8a, p. 191 Reduced Ranges Black Rhino Range in 1700 Range today (about 2,400 left) Fig. 9-8b, p. 191 Reduced Ranges African Elephant Probable range 1600 Range today (300,000 left) Fig. 9-8c, p. 191 Reduced Ranges Asian or Indian Elephant Former range Range today (34,00054,000 left) Fig. 9-8d, p. 191 Endangered Ring-tailed Lemur Fig. 9-9, p. 192 Threatened Species of U.S. Songbirds Cerulean warbler Sprague's pipit Bichnell's thrush Blacked-capped vireo Golden-cheeked warbler Florida scrub jay California gnatcatcher Kirtland's warbler Henslow's sparrow Bachman's warbler Fig. 9-10, p. 192 Threats from Nonnative Species Deliberate and accidental introductions Many valuable crops and livestock are nonnative Economic and environmental costs Impact on native species, property, and agriculture Kudzu Fire ants Deliberately Introduced Species Purple looselife European starling African honeybee ("Killer bee") Nutria Salt cedar (Tamarisk) Marine toad Water hyacinth Japanese beetle Hydrilla European wild boar (Feral pig) Fig. 9-11a, p. 193 Accidentally Introduced Species Sea lamprey (attached to lake trout) Argentina fire ant Brown tree snake Eurasian muffle Common pigeon (Rock dove) Formosan termite Zebra mussel Asian long-horned beetle Asian tiger mosquito Gypsy moth larvae Fig. 9-11b, p. 193 Kudzu Fig. 9-12, p. 194 Fire Ant Invasion 1918 2000 Fig. 9-13, p. 195 Reducing Threats from Nonnative Species Prevention is best Identify the characteristics of nonnative species Identify vulnerable ecosystems Thoroughly inspect imports Establish appropriate international laws Discharge of ballast waters from ships Characteristics of Successful Invader Species and Vulnerable Ecosystems Characteristics of Successful Invader Species High reproductive rate, short generation time (r-selected species) Pioneer species Long lived High dispersal rate Release growthinhibiting chemicals into soil Generalists High genetic variability Characteristics of Ecosystems Vulnerable to Invader Species Similar climate to habitat of invader Absence of predators on invading species Early successional systems Low diversity of native species Absence of fire Disturbed by human activities Fig. 9-14, p. 195 Extinction Threats from Poaching Profits of poaching Causes of poaching: food, fur, pets, traditional medicines, trophies, eliminating pests, etc. Bushmeat Illegal pets and decorative plants Attempts to control poaching Bushmeat Fig. 9-15, p. 196 Extinction Threats from Climate Change and Pollution Greenhouse effect Pesticide threats DDT biomagnification (bioaccumulation) Biomagnification of DDT DDT in fish-eating birds (ospreys) 25 ppm DDT in large fish (needle fish) 2 ppm DDT in small fish (minnows) 0.5 ppm DDT in zooplankton 0.04 ppm DDT in water 0.000003 ppm, or 3 ppt Fig. 9-16, p. 197 Protecting Wild Species International treaties and conventions Convention on International Trade in Endangered Species (CITES) Convention on Biological Diversity (CBD) US federal law Lacey Act Endangered Species Act (ESA) National Marine Fisheries Service Foreign species and ESA Establishing critical habitats Habitat conservation plans Role of private landowners, loggers and developers ESA and commercial shipping Biodiversity Hot Spots in the US Top Six Hot Spots 1 Hawaii 2 San Francisco Bay area 3 Southern Appalachians 4 Death Valley 5 Southern California 6 Florida Panhandle 2 4 5 3 6 1 Concentration of rare species Low Moderate High Fig. 9-17, p. 199 Confiscated Products From Endangered Species Fig. 9-18, p. 199 Protecting Marine Species Role of the Endangered Species Act Threats from litter Threatened sea mammals Threatened sea turtles Poaching and threats from fishing nets Need more knowledge of marine biodiversity Difficulty enforcing international treaties Litter Kills Seals Fig. 9-19, p. 200 Endangered Sea Turtles Fig. 9-20, p. 200 Endangered Species Act Weaken the Act? Strengthen the Act? Accomplishments of the Act: Case Study, p. 201 Should we try to save all species? How Would You Vote exercise Protecting Wild Species: The Sanctuary Approach Wildlife refuges and protected areas Gene banks, botanical gardens, and farms Zoos and aquariums Limitations of zoos and aquariums Reconciliation Ecology Promoted by Michael L. Rosenzweig Learning to share with nature Making our habitats more compatible for wildlife Diversify yard plants Neighborhood contests and awards Biological diverse golf courses, campuses, and cemeteries San Francisco's Golden Gate Park Science Spotlight: protecting bluebirds, p. 204 What Can We Do to Protect Species? What Can You Do? Protecting Species Do not buy furs, ivory products, and other materials made from endangered or threatened animal species. Do not buy wood and paper products produced by cutting remaining old-growth forests in the tropics. Do not buy birds, snakes, turtles, tropical fish, and other animals that are taken from the wild. Do not buy orchids, cacti, and other plants that are taken from the wild. Fig. 9-21, p. 204 ...
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- Spring '08