“…Therefore, in a broader sense, we are concerned with richness-area relationships and abundance distributions, so that there are biorichnessarea relationships and biotaxa-abundance distributions, in macroecology, and pedorichness-area relationships and pedotaxa-abundance distributions in pedology. These concepts have been applied to soils (Ibáñez et al, 1995(Ibáñez et al, , 1998(Ibáñez et al, , 2005aPhillips, 2001;Guo et al, 2003a;Phillips, 2004), considering the extension of each soil type (taxon) within a region, just as an area covered by plant communities is evaluated when analyzing biodiversity in vegetation biology (Magurran, 1988). It has been found that biotic and abiotic resources follow similar patterns at different regional scales (Ibáñez et al, 1990(Ibáñez et al, , 1995(Ibáñez et al, , 1998Guo et al, 2003a;Phillips, 2004;Ibáñez et al, 2005a) and also at the planetary scale (Ibáñez et al, 2004).…”