Estimating the number of tree species in a forest community using survey data

Using some large samples as actual populations we study a series of promisi ng estimators for number of species in a population. We recommend a nonpara metric estimator, CM2f = c(s) + fc(1)/(2c(2)) where c(s) is the number of s pecies observed, c(1) and c(2) are the numbers of species occurring once an d twice respectively on the sample plots, and f is the finite population co rrection for sampling, from such data as collected by Forest Inventory and Analysis (FIA) of the US Forest Service. For FIA samples, there are estimat ed to be 0, 4, 3, 1 and 6 rare tree species not sampled in Minnesota, Misso uri, Pennsylvania, New, York, and Ohio respectively.