Biological Diversity and Conservation Chapter 5 Which do you like better? A B A B A B A B AB AB Bio = Bio diversity What does Bio mean? Diversity = Variety What does Diversity mean? There are 3 components of biodiversity 1.Diversity of genes Chihuahuas, beagles, and rottweilers are all dogsbut they're not the same because their genes are different. Chihuahua Beagle Rottweilers Diversity of species For example, monkeys, dragonflies, and meadow beauties are all different species. Saki Monkey Golden SkimmerMeadow 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 Hoh Rain Forest Florida Sand hill Pond There are 3 components of biodiversity 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) 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 1940s humans are mainly responsible DESERTIFICATION 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 cant 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. HABITAT FRAGMENTATION Fragmentation Results Habitat Degradation-- damage to a habitat by pollution 3 Main types. 1-Air Pollution 2-Water Pollution 3-Land Pollution Fish-Eating Birds Magnification of DDT Concentration 10,000, ,000 10,000 1,000, Large Fish Small Fish Zooplankton Producers Water Section 6-3 Figure 6-16 Biological Magnification of DDT 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 Cover Crops Legumes, grasses, and other cover crops recycle soil nutrients, reduce fertilizer need, and prevent weed growth. 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. Biological Pest Control The use of predators and parasites to control destructive insects minimizes pesticide use as well as crop damage 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. Crop Rotation Different crops use and replenish different nutrients. By rotating crops, the loss of important plant nutrients is decreased. ABC Yr. 1 Yr. 2 Yr. 3 Section 6-4 Sustainable Agriculture corn alfalfa oats alfalfa (plowed in) Exotic 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 ENDANGERED VS THREATENED Threatened: population low but extinction less imminent Endangered: nos so low that extinction imminent THE GREATEST THREAT Nature Preserves/National Parks Best way to conserve species is to protect whole communities and ecosystems only 6% of Earths 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 The Red Wolf has been reintroduced in North Carolina! Wolves in Yellowstone