3.1.1 Factors influencing biodiversity
Globally, biodiversity levels vary widely across land and oceans. Both physical and human factors influence levels of biodiversity and these factors operate at a variety of scales from local to global. Global physical factors such as variations in climate, play a major role in controlling the presence or absence of limiting factors, such as:
• Availability of light
• Nutrient supply
An absence of limiting factors leads to high levels of primary productivity and the energy produced leads to high levels of biodiversity. Conversely, where limiting factors are strongly evident, e.g. in cold temperatures such as ...view middle of the document...
Human factors can be considered as negative threats or as positive dealing with a spectrum of conservation strategies.
Hotspots are areas of high biodiversity. The initial terrestrial hotspots were a collection of 25, designated in 1999 as a result of the work of N. Myers, covered only 1.4% of the Earth’s land surface yet contained 44% of all the known plant species and 35% of all known animal species.
These hotspots are conservation priorities because of their high levels of biodiversity and endemism. These environments, however, are also under the greatest threat, which leads to environmental degradation of these valuable ecosystems. The sheer variety of the resources available in these hotspots increases their demand and thus are heavily threatened; potentially more-so in the future with an increasing demand due to an increasing global population. Many people argue that with scarce eco-funds it is logical to save the best-bits.
Most of the original hotspots were located in tropical areas, especially rainforests – many in LDCs where poverty is the root cause of threats to these hotspots. A criticism of this evaluation was that coverage of the world’s ecosystems was uneven because marine areas and many unusual...