OBJECTIVES

The objectives of the Soil Biodiversity Programme were:

  • To quantify the taxonomic and metabolic diversity of key groups in the soil biota in a single ecosystem, sufficient to provide a sure basis for an experimental programme to determine the role of diversity in ecosystem processes. 
  • To extend taxonomic understanding of the soil biota, especially by using isolation and molecular techniques to examine hitherto poorly characterised groups.
  • To characterise the roles played by all major groups within the soil biota (including root–microbe associations) in ecologically important processes in the carbon and nitrogen cycles in soil, including the development of carbon sinks, so as to determine the pathways and rates of movement of carbon through components of the soil foodweb.
  • To determine (both experimentally and by comparison of contrasting sites) the extent to which depauperation of the soil biota may reduce their ability to perform essential ecosystem services, including the ability to cope with anthropogenic inputs.
  • To conduct parallel manipulations of major taxonomic groups of soil biota under controlled conditions.
  • To determine the extent to which indicators of soil biodiversity are measures of the soil ecosystem resilience of relevance to land use management.

It was intended that research projects used common experimental and identification protocols, allowing a robust test of the generality of the findings.

 


BACKGROUND

  • BIODIVERSITY IN SOIL

A central question in ecology is whether there is a necessary link between biological diversity and ecosystem function. Biogeochemical cycles are among the most fundamental of the functions performed in ecosystems, and many critical processes in these cycles (e.g. decomposition, nitrogen transformations, trace gas generation) occur in soil and are mediated by soil organisms. The role of these organisms in biophysical processes (e.g. hydrological cycling, energy balances) is unclear but almost certainly profound. Soil communities are currently exposed to a wide range of impacts, including erosion, agricultural intensification, and the deposition of acidic and nitrogenous pollutants, with poorly documented effects on diversity of the soil biota, and virtually unknown effects on ecosystem processes.

  • ROLE OF SOIL ORGANISMS

Soil organisms also control the magnitude and chemical nature of the globally significant C and N fluxes from soils. The role of some bacteria in these transformations is well established, but rates and pathways of soil biological processes are typically studied as functions of environmental rather than biological variables. The roles played by most groups of soil organisms is very poorly known, although a general theoretical and conceptual framework is emerging. Experimental demonstrations of the importance of faunal-microbial interactions are rarely performed in a context where their significance to ecosystem-level processes can be inferred.

  • NEW TECHNIQUES

Basic knowledge of the diversity of the soil biota is rudimentary. Molecular techniques confirm that the undescribed diversity is large, and that this genetic diversity can be linked to process studies if it can be characterised using molecular probes and taxa assigned to functional groups. Molecular techniques now offer an unique way forward when combined with other new or advancing technologies (e.g. NMR, confocal microscopy, GC-MS) to frame answerable questions about the diversity/function relationships in soil.

  • RATIONALE

The Programme combined detailed taxonomic description with an experimental approach designed to utilise that description to test hypotheses about the functional role of biodiversity. It was based on an intensive study of a single site. Diluting the effort over a range of sites would have precluded proper investigation of functional links between taxonomic diversity and function, and intensive studies at a range of sites would have been prohibitively expensive.


 

Funded Projects

NERC GST code   

LEAD PIAFFILIATION  TITLE
First Phase   

2105

Dr Mark Blaxter

University of Edinburgh

Development of a molecular barcode system for soil nematode identification.

2108

Prof Peter Young

University of York

Function and taxonomic diversity of mycorrhizas in grassland.

2109

Dr Peter Millard

MLURI, Aberdeen

Management of Field Experiments at Sourhope.

2111

Dr Clare Robinson

Kings College, LondonBiodiversity of saprotrophic fungi of grassland in relation to their function

2113

Dr Phil MurrayIGER, North Wyke, DevonBiodiversity of invertebrate root feeders and their impact on soil microbial communities.

2115

Prof Phil InesonUniversity of York
 
Soil faunal biodiversity and carbon cycling.

2116

Dr Ian Head

University of Newcastle
 
Effects of soil improvement treatments on bacterial community structure and function.

2117

Dr Jonathan LeakeUniversity of Sheffield
 
The effects of mycorrhizal mycelium on the diversity, biomass and functioning of soil microbial communities and its role in carbon and nutrient cycles.

2118

Prof Jim ProsserUniversity of Aberdeen
 
The influence of land-use management practices on species and functional biodiversity of nitrite oxidising bacteria and nitrification and denitrification processes.

2119

Prof Charles GodfrayNERC Centre for Population Ecology, Imperial College, Silwood ParkSoil biodiversity, carbon and nitrogen fluxes in replicate, model Sourhope ecosystems: an Ecotron experiment

2125

Dr Anne GloverUniversity of AberdeenWhat is the link between microbial diversity and soil resilience?

2127

Prof Donald DavidsonUniversity of StirlingInteractions of soil biodiversity, micromorphology, structure and organic matter

2129

Prof David Hopkins

University of Stirling

Earthworm diversity and the integration of physical, biochemical and microbiological functions

2130

Dr Bland FinlayCentre for Ecology & Hydrology (Windermere)Soil Protozoan Diversity and its role in Carbon and Nitrogen turnover

2133

Dr Richard BardgettUniversity of LancasterThe relationship between diversity, biomass and function of soil microarthropod communities

2136

Dr Mark BaileyCentre for Ecology & Hydrology (Oxford)Establishing the link between functional and total bacterial diversity, its response to perturbation and effect upon carbon flux to other trophic levels

2138

Prof Elizabeth WellingtonUniversity of WarwickAssessment of chitin decomposer diversity: the role of actinomycetes and other bacteria in C and N cycling in limed and unlimed grasslands

2642

Dr Andy MehargCentre for Ecology & Hydrology (Monks Wood)Towards a quantitative analysis of soil food-web structure and function at the ecosystem scale

2645

Dr Helaina BlackCentre for Ecology & Hydrology (Lancaster)Diversity and functional activity of Enchytraeidae in an upland pasture

Second Phase

   

Standard Grants

   

150

Prof Mark Bailey

Centre for Ecology & Hydrology (Oxford)

Influence of Sourhope biodiversity treatments upon on the carbon flow and functional resilience of key bacterial taxa in the rhizosphere of grassland soils. 

160

Dr Philip MurrayIGER, North Wyke, DevonDiversity and functional role of predatory beetles and their prey in the Sourhope ecosystem.

176

Prof James ProsserUniversity of AberdeenHow does rhizosphere carbon flow drive soil biodiversity?

177

Dr Jonathan LeakeUniversity of SheffieldCarbon flow through mycorrhizal mycelial systems to soil microbial populations- their impact of microarthropod diversity.

178

Prof Philip Ineson

University of York

Carbon transfers at Sourhope - from plant to soil organic matter.

Small grants

   

143

Dr Gareth Griffith

University of Wales 

Fine scale analysis of Hygrocybe spp. In semi-natural grasslands and elucidation of their role in decomposition processes.

154

Prof Elizabeth Wellington

University of Warwick

 

Provision of a molecular archive for microbial diversity within treatments plots at Sourhope.

156

Dr Ian Grieve

University of Stirling

Flow paths and rates of labelled carbon transfer within the spatial organisation of an upland grassland soil.