The function of soil biodiversity as indicators of soil quality: Insights from the UK Defra SQID project

This presentation outlines the final results from the UK Defra SQID project which identified and piloted a
suite of biological indicators of soil quality for deployment in national-scale soil monitoring programmes to
meet a range of UK policy objectives. The indicators were selected to provide information on the soil
biological processes which underpin soil function and therefore support ecosystem services. A semiquantitative
framework was used to systematically capture the wealth of information in the literature and
from expert knowledge on potential indicators of soil quality with a total of 183 indicators assessed. Six soil
biological methods have now been piloted in the UK using two complementary field approaches. These six
reflect the genotypic, phenotypic and functional characteristics of soil biodiversity. Here we review the
results from the two field approaches, the first to assess the temporal sensitivity of biological indicators to
key environmental pressures across a 12 month window and the second to asses the ability of biological
indicators to discriminate between different habitats. We discuss the relative performance of the indicators
and how these were prioritised for national-scale soil monitoring and finally, how this process has revealed
new insights into the distribution and characteristics of soil biological properties within UK soils and habitats.