Supplement 1. R code used to calculate percent error of estimated richness in the full data set using subsets of plots of each habitat type to calculate shared species overlap among habitat types.

File List MS11-0206.Rcode.R (md5: e99ae92c8e95f222b82883641b96cf0d) Description R code used to calculate percent error of estimated richness in a full data set using subsets of plots from each habitat type to calculate shared species overlap among habitat types. Input data should be a plot by species matrix with an additional column denoting the habitat type of each of plot. In this study, the habitat types were A (arable fields), G (grasslands), P (pastures), and W (woodlots or forests). Two, three, and four way overlap terms were calculated separately using Eqs. 2 and 3, and were combined together as in Eq. 1 to estimate richness in the full data set.