Dear listers, I am using the pcnm function (spacemakeR) to obtain eigenvectors for a spatial grid of sampling sites. These pcnm eigenvectors are then used in multivariate ordination to test where community composition follows local environment or rather shows spatial autocorrelation, and get support for apatial autocorrelation. In an RDA analysis, I can see which eigenvectors correlate most with my data, which can be interpreted that the spatial scale is rather 'fine' or 'broad'. However, is there a way to read the spatial scale on which the data correlates best, i.e. is it possible to extract a spatial scale describing the apatial autocorrelation (e.g. from the eigenvalues)? My data - irregularly spaced sampling sites, total scale ca. 2000 km, most sites few tens of km apart - i use the dfunction rdist.earth to obtain a distance-matrix of all sites prior to using pcnm Thanks ! Robert Robert?Ptacnik Norwegian?Institute?for?Water?Research?(NIVA) Gaustadall?en?21 NO-0349?Oslo FON?+47?982?277?81 FAX?+47?221?852?00