Tsung-Jen Shen, Wen-Han Hwang, Chia-Jui Chuang

In this proposal, we will present a sequence of jackknife estimators for the number of shared species in two communities. With simple and explicit formulae, these estimators are supposed to be computed easily. As the jackknife order increases, the resulting estimator is expected to gain a smaller bias yet is usually accompanied with a larger variance, thus a sequential testing procedure will be proposed to determine the order in applications as well. Several typical methods will be evaluated their performance through a Monte Carlo simulation study. To mimic data sampled from the real world, two forests census datasets established in Malaysia and with 209 shared species between them were considered to be our sampling population.

**Keywords:** quadrat sampling; shared species; two-sample jackknife

**Biography:** In 2003, Shen, Tsung-Jen Ph.D. got his degree from Institute of Statistics, National Tsing Hua University in Taiwan. Now he is an associate professor, Department of Applied Mathematics, National Chung-Hsin University in Taiwan. His research is interested in developing statistical methods to deal with ecological issues, including alpha and beta diversity indices estimation, species richness prediction and so forth. For all of these topics; he and his Ph.D. advisor, Professor Anne Chao, have developed a free software, SPADE, for users.