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 dogs—but 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 1940’s –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 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.
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 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 The Red Wolf has been reintroduced in North Carolina! Wolves in Yellowstone