Question

The table below shows the number of species and Shannon Diversity Index values for 5 prairie plant communities.

Community	Number of Species	Shannon Diversity
A	10	3.5
B	25	1.3
C	10	1.3
D	20	2.4
E	4	3.1

Which community has the highest richness?

Which community is the most even?

Which two communities are equal in alpha diversity?

Which communities show the highest beta diversity?

Answer 1

Ans a. Species richness is defined as the no. of species per sample. So, the more species present in the sample the highest richness it will hold.

Here in the given above question, Community B have the highest species richness.

Ans b. The evenness matematically defined as diversity index, a measure of Shannon's diversity index H by natural logarithm of species richness ln(S) to calculate the species evenness.

Community

A = 3.5 / ln(S) = 3.5/ 2.30 = 1.521

B = 1.3/ 3.22 = 0.403

C = 1.3/ 2.30 = 0.565

D = 2.4/ 3 = 0.8

E = 3.1/ 1.4 = 2.214

The most evenness of species is found in the Community E = 2.214

Ans c. The Alpha diversity is defined as the diversity within a particular area or ecosystem and is usually expressed by the no. of species ( i.e. species richness) in that ecosystem.

Shannon Weiner index =

whereas Shannon weiner index is also known as alpha diversity.

Thus from the above given data, Community B and C have the same alpha diversity .