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Biodiversity What does “Diversity” mean? Diversity = Variety There are 3 components of biodiversity 1. Diversity of genes Chihuahuas, beagles, and rottweilers are all dogs—but they're not the same because their genes are different. Chihuahua Beagle Rottweilers There are 3 components of biodiversity Diversity of species For example, monkeys, dragonflies, and meadow beauties are all different species. Saki Monkey Golden Skimmer Meadow Beauty There are 3 components of biodiversity Variety of ecosystems Prairies, Ponds, and tropical rain forests are all ecosystems. Each one is different, with its own set of species living in it. Paines Prairie Florida Sand hill Pond Hoh Rain Forest Panda Vanishing Species Biodiversity--variety of life in an area number of different species in given area terrestrial biodiversity increases as you move closer to equator tropical regions contain 2/3 of all land species on Earth Larger islands have more biodiversity than smaller islands (similar locations/biomes) more space greater variety of enviornments and ecosystems Importance of Biodiversity Beautification Possible unknown relationships Brings stability to ecosystem Meets human needs Potential to improve health (medicines) (Fig. 5.3, p.118) Biodiversity Loss of Biodiversity Extinction--disappearance of species when last of its members dies Threatened species--declining rapidly Endangered species--numbers become so low that extinction is possible 40 extinctions since 1940’s humans are mainly responsible Biodiversity Loss Biodiversity Loss Threats to Biodiversity Changes to habitat can threaten organisms with extinction. Three main ways…. 1 -Habitat loss 2 -Habitat fragmentation 3 -Habitat degradation Habitat Loss Biggest threat to biodiversity Destruction of habitats and organisms can’t adapt Results from human actions and natural disaster Coral Reefs Habitat Fragmentation Separation of wilderness areas from other wilderness areas Ex: roads cut across wilderness, building projects, etc. Fragmentation Results 3 Main types…. 1-Air Pollution 2-Water Pollution 3-Land Pollution Figure 6-16 Biological Magnification of DDT Section 6-3 Magnification of DDT Concentration Fish-Eating Birds 10,000,000 Large Fish 1,000,000 Small Fish 100,000 Zooplankton 10,000 Producers 1000 Water 1 Air Pollution Includes acid rain Damages plant tissue and interferes with growth Changes water pH (frogs) Damages ozone (CFCs) Water Pollution Results from excess fertilizers, algal blooms, silt, detergents, heavy metals, and solid pollutants Point-source vs. Non-point source Land Pollution Pesticides DDT--Rachel Carson Peregrine falcons, bald eagles, brown pellicans, etc. (fragile eggs) Land Pollution Sustainable Agriculture Section 6-4 Cover Crops Legumes, grasses, and other cover crops recycle soil nutrients, reduce fertilizer need, and prevent weed growth. Contour Plowing Contour plowing reduces soil erosion from land runoff. On hilly areas, plowing is done across the hill rather than straight up and down. Controlled Grazing By managing graze periods and herd densities, farmers can improve nutrient cycling, increase the effectiveness of precipitation, and increase the carrying capacity of pastures. A B Yr. 1 Yr. 3 C Crop Rotation Different crops use and replenish different nutrients. alfalfa By rotating crops, the loss corn alfalfa (plowed in) of important plant nutrients is decreased. corn Yr. 2 Biological Pest Control The use of predators and parasites to control destructive insects minimizes pesticide use as well as crop damage oats alfalfa oats alfalfa corn Exotic/Invasive Species Organisms not native to a particular area Ex: Kudzu Grow at exponential rate due to lack of competitors and lack of predators May take over niches and eventually replace native species Exotic Species Conservation of Biodiversity Strategies of Conservation --plans to protect biodiversity 1 -US Endangered Species Act 2 -Nature preserves and National Parks 3 -Sustainable Use 4 -Habitat Corridors 5 -Reintroduction programs US Endangered Species Act Became law in 1973 Made it illegal to harm any species on endangered or threatened species lists Also illegal for federal agencies to fund any project that would harm organisms on these lists includes damaging their ecosystems Ex: bald eagle, American alligator Nature Preserves/National Parks Best way to conserve species is to protect whole communities and ecosystems only 6% of Earth’s land surface is protected Yellow Stone Sustainable Use Using resources of wilderness areas in ways that will not damage the ecosystem Harvesting brazil nuts rather than cutting down the trees Habitat Corridors Natural strips of land/water that allow migration of organisms from one area to another Overcomes habitat fragmentation Reintroduction Programs Release of organisms into an area where their species once lived California condors Reintroduction Programs Red Wolf Cool NC Species Hellbender Comet Darner Dragonfly Anax longipes