Abstract: Species diversity is a community parameter. It’s usually unknown , and must be estimated with a sample or samples from the community. Therefore the sampling properties of the estimators must be examined in order to accurately estimate species diversity of a community. The estimation of means and variances , hypothesis testing , and large or small sample distributions for some diversity measures are reviewed in this paper. However , the sampling properties of many diversity measures remain unclear , and some of them have not been studied at all. It is concluded that Pielou′s pooled quadrat method and jackknife method are two better methods to solve some of the problems , and jackknife method is more practical in application than the other.

Key words: infectious disease, Cyprinoid fishes, Aeromonas hydrophila, Beijing