According to the Smithsonian Institution, biodiversity has three components. "Genetic biodiversity" refers to inherited variations within an animal or plant population. For example, the Irish Potato Famine was the result of a fungus blight that targeted spuds. Deficient diversity can be natural to an area or induced by humans, but in either case there is a risk to a population's continued existence.
The second aspect, "species richness," refers to the number of species located in a particular ecosystem. A healthy environment tends to support a wide-ranging assortment of flora and fauna. In addition, global location affects diversity: More variation is found within the tropics, especially in the western Pacific region. A change in one species, however, can affect others.
The final aspect, "ecosystem diversity," considers the types of habitats within an environment. For example, does it have grasslands, freshwater, saltwater or forests? Low diversity within an ecosystem, however, does not necessarily indicate a crisis.
Genetic diversity, species richness, ecosystem diversity: all are important for a well-functioning environment. A loss of biodiversity can produce long-term, far-reaching effects.
Resource: Susan Sherwood