Trophic linkages between above- and below-ground organisms as a key to successful restoration of biodiversity on ex-arable land across Europe - TLINKS
		Simon Mortimer, Clare Lawson, Andrew Edwards, Alex Brook and Simon Potts PROJECT SUMMARY Conservation of biodiversity by restoration of species-rich ecosystems on ex-arable land is a highly unpredictable process. Often, restoration fails and the causes of failure are unknown. Poor results may occur at different scales, from the interactions between above- and below-ground organisms at the small-scale (plot level), to land use patterns and species pools at the landscape scale There is a strong need for careful targeting of areas for biodiversity conservation that have high potential for success. This is important as funds are limited and the pressure on land use for other purposes (e.g. urban areas, infrastructure, tourism) is increasing. Effective targeting requires appropriate criteria and indicators to determine if and where biodiversity conservation is most feasible and how constraints may be overcome. OBJECTIVES TLinks aims to enhance the success of schemes for the conservation of biodiversity through the restoration of species-rich communities on ex-arable land Successful biodiversity conservation depends on the functioning of the whole ecosystem, and particularly on the restoration of trophic linkages between organisms However, the soil and its biotic complexity are usually overlooked, and not included as criteria or indicators in biodiversity restoration and conservation policies This is the innovative focus of the TLinks project. APPROACH TLinks uses a range of existing restoration sites, in case study areas across Europe, to identify environmental and socio-economic criteria associated with successful and failed restoration schemes. Manipulative field experiments, replicated across Europe, are used to identify methods that enhance successful restoration by promoting trophic complexity. These experiments are complemented by glasshouse and laboratory studies. Project Initiation TLinks provides strategies for the promotion of successful restoration of biodiversity on ex-arable land, and tools that can be used by stakeholders to measure success and target resources. The end-users of the research play an important role in definition of the research requirements. The project involves: A review of scientific and technical publications on the current tools used to measure the success of restoration projects and current knowledge on factors promoting success Stakeholder workshops held across Europe to identify research requirements The publication of a User Requirement Document. Observational Studies Survey of existing sites Existing restoration sites on 90 farms and nature reserves in Spain, the Netherlands and the UK are surveyed for: Restoration success, using easily identifiable taxa (plants, butterflies, etc.) Soil characteristics, including fertility and the composition and diversity of the soil microbial community Management and other socio-economic factors (e.g. farm type, previous land use history, land management practices, etc.). Colonisation of new sites Studies of the dispersal of taxa characteristic of the target community are studied in Switzerland, the Czech Republic and the UK. They focus on the dispersal of plant species, their associated invertebrate fauna and elements of the soil biota. Experimental Studies A number of innovative field experiments are replicated at sites across Europe. In addition, mesocosm experiments are used to unravel the mechanisms behind the results of the field experiments. TLinks focuses on interactions between different trophic levels above- and below-ground by: Manipulation of the diversity and composition of the Plant Community Manipulation of the underlying Soil Conditions Plant Community Plant diversity What effect does the diversity of the plant community have on the diversity of organisms in other trophic levels? Results from a manipulative field experiment, established in 1996 at sites across Europe, show that by increasing plant diversity, the diversity of more mobile taxa is enhanced. However, many elements of the soil biota exhibit a time lag in the colonisation of new sites. We examine whether this is caused by dispersal limitation, or inappropriate site conditions. Genetic provenance Does the origin of seed used in restoration practices matter? Does seed of local provenance perform better than seed of non-local genotypes? What are the consequences of using non-local genotypes for other taxa associated with particular plant species? We use reciprocal transplant experiments, established at sites across Europe, and monitor the performance of plants and their associated fauna. Keystone species What is the effect of sowing certain plant species on the development of other trophic levels? Are there certain plant species which promote the development of below-ground biodiversity and thus act as ‘keystone species? An experiment, established at sites in two countries, is used to examine the relationship between plant species characteristics and the development of below-ground biodiversity. Soil Conditions Management practices aimed at restoring biodiversity on ex-arable land involve manipulation of vegetation development through techniques, such as seed sowing and ongoing management. Experiments focus on: The use of Soil Translocation as a means of enhancing colonisation by a range of soil organisms The addition of Carbon Amendments to the soil to reduce nutrient availability through the stimulation of soil microbial biomass. OUTPUTS The results will be of practical significance in ensuring the success of restoration of biodiversity on ex-arable land. They will be of interest and relevance to a wide range of end-users, from farmers and conservation organisations to advisory services and government agencies. The project will provide a number of tools for this purpose: Management techniques to promote trophic complexity and the development of the target ecosystem Tools to assess the success of ongoing restoration schemes Criteria to identify sites where the likelihood of successful biodiversity restoration is high The results will be relevant to policy makers in refining current agri-environment schemes and developing future policies. Research findings will be disseminated through: An international workshop in the final year of the project Articles in relevant popular media Publications in international journals Scientific presentations at conferences, contribution to electronic conferences Use of field experiments as demonstration sites for end-users Participation in the activities of research project clustering A regularly updated TLinks web-site Research Partners Netherlands Institute of Ecology (NIOO-KNAW), Heteren, THE NETHERLANDS Department of Ecology, Lund University, SWEDEN Department of Botany, University of South Bohemia, Ceske Budejovice, CZECH REPUBLIC Instituto Resources Naturales y Agrobiologica (CSIC), Salamanca, SPAIN Département de Biologie/Ecologie et Evolution, Université de Fribourg/Pérolles, SWITZERLAND Funding European Commission (Project EVK2-CT-2001-00123)