This script is useful to process the statistical analysis in order to rank the environmental parameters explaining the distribution microorganisms. This procedure, using R software, is divided into several step : i- a descriptive analysis according the various dependant variables ; ii- a Principal Coordinated of neighbor matrices analysis ; iii- Pre-selection of environmental variables ; iv- Identification of the best model and variance partitioning ; v- Testing the PCNM variables on the residuals of the model; vi- Compilation of the results in tables, saving and plotting. This procedure requires that the independent variable (to explain) follows a Normal distribution or that the residuals of the linear model are normally distributed. This procedure is currently running with various microbial variables such as taxa distribution, richness or molecular microbial biomass.