- Created by: Ruby
- Created on: 11-06-12 20:32
Factors affecting Biodiversity- Global
Size of Area - Overall biodiversity increases with area, because large continious biomes support a wide range of species with extensive boundries encouraging migration.
History and Age - In general, biodiversity is greatest in the oldest and leat disturbed ecosystems, especially in the tropics, where there are few physical constraints on productivity.
Isolation - Geographical isolation, partiually on remote islands, reduces te number of species but encourages enedmism, as the remaining species develop in a distinctive way - for example, the Galapagos island or Madagascar.
Altitude Range - A large altitudinal range means a cross-section of different climates. The more climatic zones involved, the more diverse the habitats. The same principle applies to the ocean depths.
Factors affecting Biodiversity- Reigional
Productivity - This is probably the most significant factor. High temperatures and humidity levels, rich supplies of nutrience and light for photosynthesis, and a lack of annual seasons all encourage high primary productivity and therefore abundant energy, for example rainforest and coral reefs. Conversely, factors affecting limited growth reduce the range and numbers of species.
Habitat architecture - high primary productivity encourages the development of a complex trophic pyramid with many ecological niches. This system is capable of supporting high levels of biodivesity.
Habitat heterogeneity - a varied physical environment will harbour greater biodiversity because it provides a wider range of habitats for a larger verirty of species.
Factors affecting Biodiversity- Local
Succsession - Biodiversity increases as species establish themselves, interact and subtaly alter the environment. This is well illustrated by the sucsession that occur in sand dunes or a pond. In general the biodiversity of an area will increase overtime with the immigration, establishment of species leading to sucsession.
Interaction between species - This can lead to competition which in turn may drive certain speces to extinction, particually if exotic species are introduced.
Disturbance - major environmental disasters such as bish fires, flooding and storms can destroy biodiversity.
Dispersal - Individual species' dispersal and colonisation rates have an impact on biodiversity. High rates of efficiency enhance biodiversity.
Factors affecting Biodiversity- Human
Undisturbed ecosystems provide a greater range of niches and therefore higher levels of biodiversity. It is customary to think of human factors as entirely negative an threatening to biodiversity and ecosystem, but this is not always the case. Well-managed habitats combined with effective conservation strategies can have a possitive impact on biodiversity. It is also possible for people to improve degraded and damaged ecosystems so restore biodiversity.