UC Riverside

Comparing species assemblages at different times and locations provides useful

information regarding the ecosystem. Due to the unique structure

of abundance data often collected in species assemblage, appropriate

statistical tests are in need. In this thesis, we propose two types of tests,

one is data depth based nonparametric test, the other is a zero-inflated Poisson mixture model based test. These two types of tests are developed for different testing objectives and under different assumptions. We use simulation to demonstrate that their performance is better than that of the existing tests. We also discuss the differences of these two tests.