Species richness is simply a count of different species in a given area.
Species diversity is the number of species and the abundance of a particular species that inhabits a particular community. Species diversity takes into account two factors - 1. species richness and 2. species evenness. Species richness is simply a count of different species in a given area and species evenness refers to how many individuals of the different species are present. That is if there are 40 foxes, and 1000 dogs, the community is not very even. But if there are 40 foxes and 42 dogs, the community is quite even.