What do we call the variety of species in a given ecosystem?

Biodiversity refers to the variety of species present in a given ecosystem. It encompasses not only the number of different species (species richness) but also the genetic diversity within those species and the ecosystems themselves. High biodiversity contributes to the resilience of ecosystems, allowing them to adapt to changes and disturbances, maintain ecological processes, and provide essential services.

While species richness specifically refers to the count of different species, biodiversity is a broader concept that incorporates this idea along with the variety of organisms and their interactions within an ecosystem. Population density measures how many individuals of a particular species inhabit a given area, and ecological balance relates to the equilibrium between different species and their environment.