Understanding biological diversity in soil: The UK's Soil Biodiversity Research Programme

We describe the origins, development and characteristics of a major programme of research into soil biodiversity, the NERC Thematic Research Programme ‘Biological Diversity and Function in Soils’. The programme was conceived to address a number of questions relating to the role of biodiversity in the ecological functioning of soils. It had six scientific aims, which in outline were: (i) to quantify the taxonomic diversity of key groups of the soil biota in a single ecosystem; (ii) to extend taxonomic understanding of the soil biota, especially to poorly characterised groups; (iii) to characterise the roles played by all major groups of the soil biota in the ecologically important process of the carbon cycle; (iv) to determine the extent to which depauperation of the soil biota may reduce its ability to perform essential ecosystem services; (v) to conduct parallel manipulations of major taxonomic groups of soil biota under controlled conditions; (vi) to determine the extent to which soil biodiversity is an indicator of soil ecosystem resilience. The research was focussed on a single, upland grassland site and combined both field studies and experiments in controlled laboratory conditions. We present the rationale for the study, provide information on the field site and the experimental design, and then give results of the background monitoring of both the soil chemistry and the botanical composition during the progress of the research. These changes reflect the results of the major treatments (N and Ca applied singly and in combination) in the experimental design. We briefly review the main achievements of the programme (such as understanding the outstanding diversity of the small soil organisms – bacteria, protozoa, mycorrhizal fungi and nematodes – and the speed with which processes in the soil occur) and argue that the research has made substantial advances towards our understanding of both the extent and function of the biological diversity of soil ecosystems.