EcoSim allows you to test for community patterns with non-experimental data. EcoSim performs Monte Carlo randomizations to create “pseudo-communities,” then statistically compares the patterns in these randomized communities with those in the real data matrix. These null model tests have wide applicability in both applied and basic ecology. Kinds of questions you can ask with EcoSim are: 1) Is the species richness and evenness of unpolluted streams significantly different from that of polluted streams? 2) Is there evidence for unusual segregation in diet or perching microhabitats of co-occurring lizard species? 3) Does the taxonomic diversity of an avian island community differ from that of the adjacent mainland source pool? EcoSim Professional contains all the models in the free EcoSim “2004” version and also allows you to: • Open space-delimited text files, comma-delimited text files, and Excel data files • Increase the number of simulations for certain models • Save pairwise values in matrices and in columns for the Co-occurrence, Niche Overlap, and Range Overlap models as space-delimited text files, comma-delimited text files, or Excel files • Save species diversity and abundance curves as space-delimited text files, comma-delimited text files, or Excel files • Create random matrices: "1,0" (e.g., presence-absence), "0<=X<1" (non-negative real numbers from 0 to 1), or "0<=X<10" (non-negative integers from 0 to 10). • In addition, EcoSim Professional has improved menu and help systems and includes two new models: • Species Overlap • Range Overlap