New robust weighted averaging- and model-based methods for assessing trait-environment relationships: R-code

This is the R-code belonging to the paper New robust weighted averaging- and model-based methods for assessing trait-environment relationships. It contains two new methods, a new weighted averaging method and a new model-based method: 1. The new weighted averaging method combines site-level CWM with a species-level regression of Species Niche Centroids (SNC) on to the trait. The regressions are weighted by Hill's effective number (N2) of occurrences of each species and the N2-diversity of a site, and are subsequently combined in a sequential test procedure known as the max-test. 2. Using the test statistics of these new methods, the permutation-based max test provides strong statistical evidence for trait-environment association in a plant community dataset, where existing methods show (very) weak evidence. The powers of the two new methods were similar in a simulation study based on this dataset.