Question

What is species richness?

Answer 1

Hint: The term biodiversity or biological diversity is derived from the two Latin words 'bio' (means life) and 'diversity' (means variation). Thus, biodiversity counts for the variation among the biotic components of the biosphere. It can be defined in terms of ecosystems (terrestrial, marine), genes, and species.

Complete answer:
Biodiversity is a broad term that includes species diversity, genetic diversity, and ecosystem diversity. It is the mere collection of genetic variation of all species in the global ecosystem, and it is measured in terms of species richness and evenness. Here, species richness is nothing but the number of organisms that exist in a given community or area, and species evenness is the relative abundance of the distinct species in an area of a particular habitat or ecosystem.
Species richness is further categorized into alpha diversity, beta diversity and gamma diversity. Alpha diversity (point diversity) is the species richness at a given area that is comparatively smaller than the entire species distribution. Beta diversity is the rate of change of species richness across a region from one habitat to another. At the same time, gamma diversity is the species richness confined to an entire region.
It was estimated that species richness is being declined due to natural and anthropogenic activities. Species richness is declined by the elimination of species due to the introduction of invasive alien species, overexploitation, habitat loss and fragmentation, undesirable climatic changes, etc.

Note:
All the components of biodiversity are interconnected- for example, species diversity of organisms is necessary for the maintenance of a stable, sustainable and productive ecosystem, and the existence of an ecosystem itself is crucial for the survival of organisms. Thus, it implies the importance of conservation of species richness and, thereby, biodiversity of our biosphere.