What are alpha, beta, and gamma diversity? Biology Q&A (2024)

Biodiversity:

1. Biodiversity refers to the diversity of species at all levels of biological structure.
2. When ecologists researched biodiversity in the environment, they saw a consistent pattern in how diversity was dispersed across the globe.
3. Diverse patterns of variables were identified by ecologists.

The three indices of diversity are – i) Alpha, ii) Beta, and iii) Gamma diversity:

i) Alpha Diversity:

1. It is calculated by counting the number of taxa (typically species) present in a given region, community, or ecosystem.
2. Consider a mountain slope, there will be a variety of woodland and grassland areas on this hillside.
3. Alpha diversity refers to the variety of species found in each forest or grassland area on the slope.

ii) Beta diversity:

1. It is the number of species unique to each environment that is used to calculate species diversity between two nearby ecosystems.
2. Considering the above slope example, the species diversity between any two patches and their communities in that particular slope represents beta diversity.

iii) Gamma diversity:

1. It refers to the habitat variety over the whole landscape or geographical area.
2. In the example of the slope, the species variety along the full range of the mountain slope is referred to as the gamma diversity of the landscape.