Soil communities (Acari Oribatida, Hexapoda Collembola) in a clay pigeon shooting range

Clay pigeon shooting ranges can be an important source of heavy metal contamination in terrestrial ecosystems. The pellets contained in spent ammunition are mainly composed of lead (Pb) and antimony (Sb). Total concentrations of these metals were measured in soils from seven sampling sites within a clay pigeon shooting range and compared with two controls to investigate the effects of their increased levels on the oribatid mites and Collembola community. We found that the spatial distribution of Pb and Sb contamination in the fall-out area is strongly related to the flight path of pellets. Oribatid and Collembola communities are able to survive at levels of heavy metals far higher than the lethal concentration for the most tolerant plants but oribatid mites seem to be affected by heavy metals more than springtails. Collembola and oribatid mites exhibit a wide range of responses to disturbance and many species are more strongly influenced by microhabitat characteristics than levels of pollution. The effects of annual cultivations conducted in the shooting range and those of heavy metal pollution result in a simplification and homogeneity of community composition. Among arthropods, oribatid mites and springtails have a great potential as bioindicators of environmental conditions; the issue remains as to whether differences in population structure can be used to determine the type of disturbance.