# Diversity t test

Comparison of the Shannon and Simpson diversities in two samples. Requires two columns of abundance data with taxa down the rows. The Shannon t test is described by e.g. Hutcheson (1970), Poole (1974), Magurran (1988). The Simpson t test is given by Brower et al. (1998). This is an alternative to the randomization test available in the Diversity permutation test module. The Shannon index here include a bias correction and may diverge slightly from the uncorrected estimates calculated elsewhere in PAST, at least for small samples. For mathematical details, see the Past manual.

#### References

Brower, J.E., Zar, J.H., von Ende, C.N. 1998. *Field and Laboratory Methods for General Ecology*. McGraw-Hill, Boston.

Hutcheson, K. 1970. A test for comparing diversities based on the Shannon formula. *Journal of Theoretical Biology* 29:151-154.

Magurran, A. 1988. *Ecological Diversity and its Measurement*. Princeton University Press.

Poole, R.W. 1974. *An Introduction to Quantitative Ecology*. McGraw-Hill, New York.