Biodiversity
Biodiversity is the combination of the two words 'biological' and 'diversity', and describes the number of life-forms in an area or ecosystem.
Billions of years of evolution have resulted in such a number of species that it is difficult to count. Scientists estimate there are currently many millions of different species on Earth.
The health of an ecosystem can be measured by its biodiversity. All around the Earth there are different levels of biodiversity. For example, biodiversity is richer (more species in an area) near the tropics.
A region with a large number of species native to the area is called a biodiversity hotspot. Ecosystems with higher biodiversity have higher resilience. They are able to recover after a sudden change or event. Biodiversity affects the capacity of living things to respond to changes in the environment. 1
Biodiversity provides anthropogenic (human) benefit other than aesthetic value. Medicine, agriculture, industry, recreation, tourism, and economy are all benefited by ecosystems. For instance, water resource protection and soil formation and protection are services performed by ecosystems.
Ecosystems are capable of nutrient storage and recycling, pollution breakdown and absorption, and contribute to climate stability.2
Higher levels of biodiversity contribute to a healthier ecosystem and render ecosystems more capable of conducting these services. Forests are ecosystems that play a key role in the global carbon cycle. 3
Effects of Climate Change on Biodiversity
Climate Change, including changes in temperature and an increase in the number of extreme weather events will impact ecosystems and the biodiversity they provide. Reduction of habitat and introduced species and diseases already threaten biodiversity.
A change in climate may increase the damage caused by preexisting threats to biodiversity. Coral reefs near coastal marine systems, rangelands, alpine regions, temperate forests, and tropical forests are at risk of climate change induced damage. 4
Changes in temperature also pose a threat to individual species. Even a small change in temperature can influence breeding cycles, habitat range, and food availability of some species. This is in addition to the direct damage caused by extreme weather events.
References
1. Costanza R., d'Arge R., de Groot R., Faber S., Grasso M., Hannon B., Limburg K., Naeem S., O'Neill R. U., Paruelo J., Raskin R. G., Sutton P. & Van Den Belt M. (1997) The Value of the World's Ecosystems, Nature, vol. 387, pp. 253-260.
2. Biodiversity and Its Value (1993) Biodiversity Series, Paper No.1, Biodiversity Unit, Australian Department of the Environment, Sport, and Territories.
3. Hawksworth D. L. & Bull A. T. (2006) Forest Diversity and Management, Springer Netherlands.
4. Eds. Howden, M., Hughes, L., Dunlop, M., Zethoven, I., Hilbert, D. & Chilcott, C. (2003) Climate Change Impacts on Biodiversity in Australia, CSIRO Sustainable Ecosystems, Canberra, Australia.