G.4 Conservation of biodiversity

1. G.4 Conservation of biodiversity Indicator species – sensitive to environmental change (such as canary in coal mine) Lichen Macroinvertebrates

2. Biotic index – calculated by sampling indicator species in a habitat. The number of each species is multiplied by a factor determined by how sensitive it is to pollution (see page 583) The total number is the biotic index. The higher the biotic index, the healthier the area.

3. Factors leading to extinction Loss of habitat Overexploitation (food, medicine, beauty) Introduction of exotic species Disease Pollution Limited distribution

4. Features of nature preserves Large size is preferred because small sites will have smaller populations and be more exposed to “outside” world Edge effect – the edge of a preserve is affected by disturbed areas around it. Organisms compete with those outside the reserve. Corridors connect isolated habitats allowing wildlife to travel between protected areas. What are some problems with corridors

5. Management of Nature Preserves Must be restored to natural state ex) Florida is restoring sandhill ecosystem required by gopher tortoise Restoration of habitat allows threatened species to recover Exotic species must be removed Area must be protected from development and/or pollution Money must be spent and projects must be prioritized for maximum benefit

6. A tortoise website http://www.nbbd.com/godo/ef/gtortoise/

7. In situ conservation methods Allow target species to adapt to conditions in a reserve without outside influence Maintains habitat Defends from predators Removes invasive species Maintains large population Has a large enough population to have genetic diversity

8. Ex situ conservation Sometimes the species is so endangered the population is too small to leave unprotected Captive breeding can increase reproductive output and ensure survival of offspring Zoos often are involved in this Includes Artificial insemination Embryo transfer to surrogate mothers Cryogenics – freezing eggs and sperm for future use Human raised young Pedigree limits inbreeding

9. Captive breeding may introduce disease or produce young who do not function well when released into wild

10. Botanical gardens preserve plant species Seed banks – store seeds in cold dark conditions to prevent germination. Preserves species for future use