Supplement 1. R script files used for the rarefaction analysis and null model code to assess data constraints.

File List rarefmat.R (MD5: 8adbb322bc311ae7073b766aff35dd61) null_model.R (MD5: eba027b2849baf889bc70036549a2aeb) Description The file 'rarefmat' contains the scripts for the function <i>rarefmat</i> in R. The function compares the Bray-Curtis dissimilarities between two matrices of the same dimensions, and rarefies one by sampling a given proportion of interactions (0.8, 0.6, 0.4 and 0.2). It returns the observed dissimilarity between the original matrices and the mean and confidence limits of dissimilarities of rarefied matrices for each level of sampling. The file 'null_model' contains the script for the null model function to assess the constraints of a triangular pattern in the relationship between floral composition and flower traits. The function call is null_model(x,y), where x and y are the two variables with a triangular relationship. The null-model calculates Spearman correlation coefficients <i>r_s</i> of randomly generated data (999 iterations) that were restricted by the limits of the observed data.