ABSTRACT
The computer program CA (Community Analysis) for IBM-PC’s and compatible machines is presented as a tool for statistical evaluation of biological data of freshwater field tests. It allows one to carry out different kinds of data transformation and statistics:
Descriptive statistics for each taxon
Parametric and nonparametric tests to examine differences in population densities after different treatments and computing of LOECs and time of recovery
Regression analysis (including probit analysis) of dose-response relationships to compute EC-values
Computing and testing of different measures of diversity
Computing of similarities including a permutation procedure to test significance (‘Randomized Similarity Analysis’).
Results are presented in graphs (time series or dose-response curves) and in tables. Application of CA is shown for experiments with aquatic outdoor microcosms.
