Answer:
- The species diversity and ecological variations of all living organisms, plants, and microorganisms found in a specific geographic area are called biodiversity. To measure biodiversity, in 1960, R. H. Whittaker classified it into three levels:
Alpha Diversity:
- It measures the number of species, i.e., species richness, found within a single specific habitat or ecosystem. This is local-level diversity, such as the diverse species of aquatic birds and plants in a specific wetland block of Keoladeo National Park.
Beta Diversity:
- It indicates the rate of change in species (species turnover) and comparative variation between two distinct or adjacent ecosystems/communities. It reflects species change upon transition from one habitat to another, such as the comparative species difference present between the arid desert ecosystem of Thar and the deciduous forest ecosystem of the Aravallis.
Gamma Diversity:
- It is the measurement of the overall species diversity across all ecosystems present within a broad geographic area or an entire landscape. It is the integrated form of all alpha and beta diversities of that large region, such as the total biodiversity of all forests, plateaus, and grasslands of the entire state of Rajasthan or the Western Ghats.