List and explain functions that biodiversity provides for human society
- Many ethicists argue for the intrinsic value of the natural world. However, biodiversity has more than sentimental value.
- Many communities provide important ecosystem services, such as oxygen production, improved hydrology, and carbon cycling.
- Biodiversity provides a reservoir of new crops and pharmaceuticals (chemical prospecting), as well as a genetic reserve for improvement of established crops.
- Ecotourism has provided new economic incentive for maintaining biodiversity.
List the types of biodiversity, and describe the difference between Endangered Species Act rankings.
Biodiversity types:
- genetic (within species)
- species/taxa
- ecosystem diversity
Endangered Species Act includes classifications for:
- endangered species: one "in danger of extinction throughout all or a significantportion ofits range"
- threatened species: those likely to become endangered in the forseeable future
Describe the pattern of biodiversity on the planet and potential causes for this pattern.
Correlates/potential generators of high biodiversity (see Communities lecture)
- Sufficient energy and water input for longer food chains.
- Habitat complexity and consequent organismal specialization.
- Species richness of a region is directly correlated with area and distance to other habitat patches.
Some locations in the biosphere are especially rich in species
- these are termed biodiversity hotspots, e.g. Central America (terrestrial) and the Western Indo-Pacific (marine).
- many hotspots hold disproportionate numbers of endemic species
List five major threats to biodiversity and briefly explain their mechanisms
Humanity's style of resource use, coupled with the recent technology and population explosion presents several threats to the maintenance of biodiversity
- Habitat destruction on global or local scales or habitat fragmentation leads to smaller population sizes.
- Biodiversity hotspots are often located in developing countries that are currently in phases of high development, or political instability.
- Increased movement of people and goods have compounded problems with invasive species.
- Populations of many species are victims of overexploitation or increased pollution (e.g. biological magnification; eutrophication)
- The extent and rate of global climate change (warming, ozone layer loss, etc.) threatens many species.
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