Spatial heterogeneity is one of the characteristic features of the soil environment. This is especially true for forest soils, which areusually not subject to human manipulation over long periods oftime and in which heterogeneity easily develops by uneven litter decomposition, the tree effect and other factors. While the verticalstratification of forest soils is widely recognized, the extent ofhorizontal heterogeneity has scarcely been addressed (Ettema and Wardle, 2002