Soil biodiversity and ecosystem function

Many ecosystem processes are sensitive to changes in biodiversity. However, although the diversity of life within our soils is vast, we are remarkably ignorant about the importance of this diversity in mediating processes such as decomposition, nitrogen mineralisation, methane oxidation-production etc, or the resilience of soil ecosystems when biodiversity is altered, for example through changes in farming practices or pollution impacts.

Our research is focused on understanding, and quantifying, the role of soil biodiversity (from the individual organism to the community-level) in the regulation of biogeochemical cycling. We examine the soil at many different spatial scales, from laboratory microcosm experiments under tightly controlled environmental conditions to field-scale experiments and regional/national-scale surveys. We are also involved in efforts to advance the theoretical modelling of C and N cycling in soils.

In recent years, we have made significance advances in our knowledge of the link between microbial and invertebrate communities and carbon cycling through the application of molecular and stable isotope techniques, for example through projects funded by the NERC Soil Biodiversity Programme and NERC PhD studentships.

One of our main interests is to explore the links between soil micro-organisms, processes and pollutants, from molecular to community level effects, in a range of environments. This includes studies on the degradation of organic pollutants, soil processes such as methane oxidation, impacts of pollutants on soil microbial communities and microbial diversity. The section has comprehensive facilities for traditional microbiological (microbial counts, respiration), chemical (biomarkers, phospholipid fatty acids (PLFAs)) and molecular (DNA/RNA, PCR) techniques which can be used to study microbial ecology. We have been involved in the development of stable isotope labelling techniques in order to directly link function with taxonomic identity through analyses of 13C-labelled biomarkers such as PLFAs and DNA or RNA. These techniques are currently being applied to study the impact of irradiation and flooding on the cycling of carbon in soils.

See also: Biological indicators of soil quality.