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:
• Temperature
• Availability of light
• Humidity
• Nutrient supply
• etc.
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 the Arctic, arid regions like deserts, darkness, etc. this will lead to low levels of biodiversity. The size of the area is another key factor, as the larger the continuous area the more species that can flourish in it. Hence the recent ‘size matters’ mantra, and the creation of huge transnational conservation areas such as the Peace Parks of Africa.
Locally, there are numerous factors that may have an impact on biodiversity:
• Disturbance from a natural disaster e.g. hurricanes, volcanoes, tsunamis on both land and ocean ecosystems, Asian tsunami 2004 – destroyed some mangrove forests
• Quasi-natural disasters, e.g. wildfires (Victoria, Australia 2009), hunting, fishing, slash and burn farming
• Eutrophication from high-tech agricultures
Physical factors Human factors
• Climate, e.g. temperature, rainfall, amount of light (limiting factors)
• Latitude, altitude and gradient
• Nutrients – vegetation and rate of nutrient recycling
• Topography – age and size of the area being investigated
• Island
• Endemism
• Climate change • Level of protection or management
• Level of poverty
• Exploitation of fauna and fauna: hunting, fishing, over-harvesting
• Clearance – agriculture, deforestation
• Human population – the growth, rate of development and use of...