A Comparison of Diversity Metrics in Grasslands

Background/Question/Methods

Biodiversity can be measured at a number of different scales, reflected by measures such as alpha, beta, gamma and epsilon diversity. Many different methods have been proposed to quantify beta diversity, causing difficulty and confusion as to their interpretation. We used data from 35 different grassland remnant and restoration sites to examine a few of the more common measures of beta diversity. These include additive and multiplicative beta, the most common, and one calculated from rarefaction curves. We also compared these to other metrics of diversity, including alpha and gamma diversity, evenness, Sorensen's Index and Shannon-Weiner Index.

Results/Conclusions

All metrics were significantly correlated with each other with the exception of multiplicative beta, which was correlated only with alpha and the other measures of beta diversity, and not as strongly as the other metrics. These results suggest that most diversity metrics measure the same thing, at somewhat different scales or with different emphasis, but high diversity at one scale usually leads to or results from high diversity at other scales, at least in grasslands.