Assessing the effects of environmental pollutants on soil organisms, communities, processes and ecosystems

A wide range of pollutants reach the soils of natural and managed ecosystems in concentrations that can affect their function. These chemicals, which include pesticides, heavy metals, acid deposition and a range of industrial chemicals, can reach soils in many different ways and by various routes. The ecological impacts of these chemicals on agricultural systems can involve effects at the: (i) organism population level, in terms of individual life histories (birth rate, numbers, growth, mortality); (ii) at the community level in terms of effects on plant/plant, plant/microbial, or plant/faunal interactions, species diversity and on soil food webs; (iii) at the ecosystem level, effects on primary and secondary productivity, organic matter breakdown and nutrient cycling; (iv) at the landscape level, changes in spatial heterogeneity of plants and soil organisms, material transfer of soil and nutrients, and hydrologic transfers of nutrients. Currently available methods of assessing the effect of pollutants include single species laboratory tests, a few multi-species assays, and integrated soil microcosms and terrestrial model ecosystems. The latter two methods produce data on the effects of pollutants on populations, communities and ecosystems as well as the fate of pollutants.