Step 1: Understand the term “species richness”.
Species richness refers to the number of different species present
in a given ecosystem or geographical area.
Step 2: Relate species richness to types of biodiversity.
Genetic diversity: Variation of genes within a species.
Species diversity: Variety and abundance of different species in an ecosystem.
Community diversity: Refers to the structure and interaction of communities, not specifically species count.
Step 3: Identify the correct term.
Since the question specifically refers to richness of species,
the correct term is species diversity.
Hence, the correct answer is
\[
\boxed{\text{Species diversity}}
\]