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Estimating species numbers by extrapolation. I, Comparing the performance of various estimators using large model communities

Ulrich W.

Polish Journal of Ecology

1999

Vol. 47, no 3

271-291

A computer program was constructed that simulates large species assemblages (28 to 997 species) with various species - rank order distributions and degrees of aggregation of the species. From these model assemblages random samples were taken to study the performance of 14 estimators of species diversity. For 6 of the estimators correction factors are developed. In sufficiently large samples ( more than 2/3 of the true species number (TS) sampled) a corrected second order jackknife estimator gave the best results. 18% of the estimates ranged outside TS+-10%. If fewer species are represented in the sample (but more than 1/3 TS) two newly developed data analytical estimators performed better. Between 23 and 24%, respectively, of their estimates ranged outside TS+-20%. Crucial to the performance of all of the estimators is the sample size. The minimum sample size for an estimator to work has to contain at least 1/3 of the total species number.