Species richness is the number of species within a community
A community is a group of populations of different species living in the same place at the same time that interact with each other
Species richness is the simplest way to measure species diversity
A community with a greater number of species will have a greater species richness score
For example, a tropical rain forest has a very high number of different species so it would be described as species-rich
Species richness can be a misleading indicator of diversity as it does not take into account the number of individuals of each species
For example, habitat A has 10 different plant species and habitat B has 7 different plant species
Habitat A would be described as being more species-rich than habitat B
However, in habitat A there is only one individual of each plant species present (10 individuals present) while in habitat B there are over 20 individuals of each species present (over 140 individuals present)
This example illustrates the limitations of species richness
Conservationists often favour the use of an index of diversity as it takes into account species number and evenness