lect04-15-10

lect04-15-10 - Tropical Forests more than half of tropical...

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Unformatted text preview: Tropical Forests more than half of tropical forests are in four countries Brazil, Indonesia, Zaire, & Peru tropical forests contain 50-90% of earth's wildlife species they yield many economic products - hardwoods, food (e.g., coffee, tea, spices, nuts, chocolate, fruits), medicines, latex rubber, resins, dyes, essential oils they are home & source of livelihood for indigenous peoples Estimated Rates of Tropical Deforestation (1960 -1990) Source: FAO, 1995 widespread disagreement about reliability of estimates Causes of Tropical Deforestation population growth & poverty timber & fuel-wood demand conversion to cattle-ranching (e.g., Central America, Indonesia) short-sighted government policies - building roads & offering other incentives for colonization of tropical forests, not valuing ecological services mining & oil-drilling - pollute & degrade forests Ways of Reducing Tropical Deforestation ecotourism: promote tourism that benefits from the aesthetic, education, & recreational opportunities provided by intact forest debt-for-nature swaps: forgive foreign debt in exchange for preserving forest conservation concessions: direct compensation for effective preservation of specific forest areas decrease the fuel-wood crisis: plant fast-growing fuel-wood trees, practice less destructive logging methods, & switch to other fuels increase awareness, empower local people Why Preserve Wild Species? economic & medical importance: wild plants & animals provide a huge number of economic products products & medicines scientific importance: scientific understanding comes from study of wild species ecological importance: ecological services include nutrient recycling, watershed value, production of oxygen, moderating climate, & detoxifying toxic substances aesthetic & recreational importance: source of beauty, wonder, inspiration, & enjoyment ethical importance: many people believe that each species has an inherent right to exist Crisis of Species human activities have led to the extinction of many species, while many others are endangered or threatened endangered species - a species with so few individuals that it could soon become extinct over all or most of its range threatened species - a species that is still abundant in its natural range, but declining such that it is likely to become endangered Examples of Extinct Species passenger pigeon great auk dodo bushy seaside sparrow Aepyornis (Madagascar) Examples of Endangered & Threatened Species Endangered & Threatened Species worldwide, about 25% of mammal species are at risk of extinction Human Contributions to Crisis of Species habitat loss & degradation, habitat fragmentation commercial hunting & poaching over-fishing predator & pest control sale of exotic pets & decorative plants climate change & pollution introduction of non-native species Endangered Species Act (ESA) ESA authorizes listing & protection of threatened & endangered species National Marine Fisheries Service (NMFS) is charged with listing & protection of marine species U.S. Fish & Wildlife Service is charged with listing & protection of all other species since 1975 intense efforts have attempted to weaken the ESA ESA is still one of the most powerful means for protecting wild species - over 1100 species (60% plants, 40% animals) are currently listed ...
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This note was uploaded on 04/30/2010 for the course ARE 110 taught by Professor Ebbin,s during the Spring '08 term at UConn.

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