Soil detritivore functioning in heterogeneously contaminated soils

Spatial heterogeneity in abiotic and biotic factors is an important habitat feature of ecosystems as it facilitates potential refuges for less favourable conditions. Heterogeneously contaminated soils can affect specific groups of organisms and their functioning, both directly by toxic effects and by avoidance of contaminated micro-sites. We tested the hypothesis that horizontally heterogeneous soil characteristics affect macrofauna distribution in a river floodplain. The horizontal pattern of zinc content showed a gradual increase in concentration in eastern direction and a high heterogeneity in the southern part of the grassland. Correspondence analyses showed that vegetation and soil moisture content explained most of the variation found between different sites. Abundances of species and vegetation were not affected by contamination which was most probably due to the low bioavailability of the contaminants. The temporal dynamics showed that to have a proper assessment of species’ presence and abundances, one has to sample for consecutive weeks to ensure optimal capturing of the species present due to climatic fluctuations.