The following graphs show rank abundance data for species in three different communities P, Q and R. Based on both species richness and relative abundance, which one of the following options correctly represents the ordering of communities according to their species diversity?
Show Hint
A more even distribution of species abundance and a higher number of species indicate greater species diversity in a community.
Step 1: Understanding the rank abundance curve.
The rank abundance curve is a tool used to represent species diversity within a community. The curve plots species rank on the x-axis and species abundance on the y-axis. In this case, the graphs show how the abundance of species varies in communities P, Q, and R. The position and slope of the curve provide insight into species richness (the number of species) and the evenness of species distribution.
Step 2: Analyzing the community data.
- Community P: This community has a low species richness (with fewer species represented), and the abundance of the most dominant species is significantly higher than that of other species. This indicates lower species evenness, where one species dominates.
- Community Q: This community has moderate species richness, and the species are more evenly distributed compared to community P, though there is still a significant difference in the abundance of the dominant species and others.
- Community R: Community R has the highest species richness (with more species) and the most even distribution of species abundance, as all species have relatively similar abundances. This indicates the highest species diversity.
Step 3: Conclusion.
Based on both species richness and relative abundance, Community R has the highest diversity, followed by Community Q, and finally Community P, which has the least diversity. Therefore, the correct answer is (D) R>Q>P.
