Chapter 55 - Conservation Biology

1. Chapter 55 - Conservation Biology

2. Biodiversity Levels • Human activities are threatening the Earth’s Biodiversity • Genetic Diversity – genetic variation within a population and between populations • Species Diversity • Ecosystem Diversity

3. Hundred Heartbeat Club • Harvard Biologist E.O. Wilson • Organisms that have fewer than 100 individuals left on Earth

4. Why should we care? • Aside from human connection to nature, there are practical benefits as well • Could lose valuable crops, fibers, and medicines for human use • Ecosystem services – support human existence • Purification of air and water • Fertile soils • Detox and decompose wastes • Pollination of crops • Dispersal of seeds • Cycling of nutrients • Control agricultural pests • Protect from erosion and ultraviolet rays • Moderation of weather Rosy periwinkle – contains alkaloids that inhibit cancer cell growth

5. Svalbard Global Seed Vault • To provide insurance against both incremental and catastrophic loss of crop diversity. • Currently 741,493 seed samples (648,042 last year) • http://www.nordgen.org/sgsv/

6. Major Threats to Biodiversity • Habitat destruction by agriculture, urban development, forestry, mining, and pollution; accounts for 73% of species that have become extinct, endangered, vulnerable, or rare during modern history; 93% of coral reefs • Introduced species (invasive, nonnative, or exotic) – usually free from predators, parasites, and pathogens that can limit population growth; examples include zebra mussels, kudzu plant, African honeybee, snakehead fish, and stink bugs! • Overexploitation – harvesting species at rates that exceed their ability to rebound; over fishing • Disruption of interaction networks – keystone species, pollinators

7. Population Conservation • Attempting to conserve populations and species and prevent extinction • Small-population approach – population drops below minimal viable population (MVP) size, loses genetic variation, trapped in an extinction vortex; genetic emphasis • Declining-population approach – focus on environmental factors regardless of pop size, such as loss of habitat

8. Species Diversity Crisis • Endangered Species – in danger of extinction throughout all or a significant portion of its range • Threatened species – likely to become endangered in foreseeable future • 12% of 10,000 known species of birds and 24% of 5,000 known species of mammals are threatened • Nearly 1000 of 20,000 known plant species in US are either extinct, endangered or threatened • 20% of known freshwater fishes have either become extinct or are threatened • 32% of known amphibian species are near extinction or are endangered • Estimates show that at current rates of extinction, more than half of all currently living plants and animals will be extinct by the end of the 21st century

9. Landscape and Regional Conservation • Focus on saving entire communities, ecosystems and landscapes as compared to individual species • Establish protected areas – usually in a biodiversity “hot spot” (relatively small area with a large concentration of endangered and threatened species), most impacted biomes are rainforest and chaparral • Set up nature reserves – example of grizzly bears in Yellowstone

10. Restoration Ecology • Attempts to restore lost or degraded ecosystems to a more natural state • Bioremediation – use ability of organisms to concentrate toxins, then harvest those organisms to remove the toxin • Biological Augmentation – adding essential materials to a degraded ecosystem • Examples of worldwide restoration endeavors on pages 1226 and 1227