Chapter 56 - Conservation Biology

1. Chapter 56 - 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. A Hundred Heartbeats Club • Harvard Biologist E.O. Wilson • Organisms that have fewer than 100 individuals left on Earth • Also a 2009 book by Jeff Corwin • The Red List

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 781,148 records on file(741,493 last year) and 513,801,025 seeds • 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 21% of 5,500 known species of mammals are threatened • Nearly 1000 of 20,000 known plant species in US are either extinct, endangered or threatened • 21% of known freshwater fishes have either become extinct or are threatened • 32% of known amphibian species and 21% of known reptiles 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 • Source: International Union for Conservation of Nature and Natural Resources (IUCN) and Cener for Plant Conservation.

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