You are hiking within the northern hardwood forest region of the upper peninsula of Michigan and you pass through two small woodlands. Because we have turned you into a biology enthusiast, you count and identify all the trees that you pass. In woodland A, you find 50 sugar maple trees, 50 yellow birch trees, and 50 red oak trees. In woodland B, you find 100 sugar maple trees, 48 yellow birch trees and 2 red oak trees. The most accurate comparison of these woodlands would be that

A. they differ in both tree species richness and diversity.
B. they have equal tree species diversity.
C. they differ in insect species richness.
D. they differ in primary productivity.
E. they have equal tree species richness.

Species richness measures the number of species present in an ecosystem. More the number of species, more rich is the ecosystem. Species diversity measures the distribution of each species in the ecosystem.

Here, both the woodlands have three species of trees so they have equal tree species richness. However woodland A has equal number of trees in each species and woodland B has very high number of sugar maple trees and very low number of red oak trees. Hence, woodland A is more diverse than woodland B.