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Biodiversity yields dividends, finds pan-European research

Embargoed for release
19:00 GMT Thursday 4 November 1999

The loss of biodiversity in European grasslands will make them less productive, reducing the amount of energy available to the rest of the food chain and threatening the overall health of the ecosystem, say results from one of the world's most extensive ecological studies published in Science tomorrow. (Notes to Editors 1)

A team of scientists from eight European countries, led by Professor John Lawton at the NERC Centre for Population Biology at Imperial College of Science, Technology and Medicine, say that their experimental evidence should send a clear message to European policy makers: that preserving and restoring biodiversity is beneficial to maintaining grassland productivity - particularly if reductions in fertiliser and pesticide usage are to be achieved. About half of Europes farmland is grassland (60 million hectares), used as grazing pastures, hay meadows, and as set-aside land.

"Loss of species is playing a key role in the gradual erosion of the quality of our environment. In addition to moral and aesthetic reasons to conserve biodiversity, our results now provide strong scientific reasons too," says Dr Andy Hector of Imperial College, lead author of the groups report in Science. "These results provide the type of general ecological principles needed for European conservation and agricultural policies".

The significance of the fall in productivity that accompanies biodiversity loss is explained by Professor Lawton, who recently became Chief Executive of the Natural Environment Research Council (NERC) (2). "Plant communities are solar power stations that produce food energy for everything else. Ultimately we are all dependent on plant productivity for our energy," he said.

The results of the project, named BIODEPTH (3), clearly show that plant communities grow better in species-rich teams, and that their productivity decreases when diversity declines (4). Harvest yields were found to increase when there was a range of plants with different characteristics growing together. Similar patterns occurred in a broad range of European grasslands, making the findings applicable on a continental scale.

These findings represent the latest development in the scientific debate about how the loss of biodiversity affects the way in which ecosystems function - recently a major focus of ecological research. The BIODEPTH evidence provides a vital contribution to the debate by demonstrating that both numbers of species and the types (5) of plant play important roles in ecosystems.

To reach these conclusions the team of 34 scientists assembled miniature experimental grasslands at eight field sites across Europe, ranging from Greece to Sweden (6). The grasslands were varied in plant diversity to mimic the gradual loss of species seen throughout Europe.

The reviewers of the Science paper describe BIODEPTH as a pioneering ecological experiment because it is the most extensive multinational collaboration to perform the same standardised experiment at a continental scale. Funded by the European Commission to the cost of 2 million Euros, it signals the beginning of a new era by demonstrating the power of "big ecology" to underpin environmental policymaking.


For more information please contact:

Dr Andy Hector, BIODEPTH Project Co-ordinator
NERC Centre for Population Biology, Imperial College at Silwood Park
Ascot, Berks SL5 7PY, U.K
Telephone: +44 01344 294494 Fax: +44 01344 873173

Dr Phil Heads, Manager
NERC Centre for Population Biology, Imperial College atSilwood Park
Ascot, Berks SL5 7PY, U.K
Telephone: +44 01344 294223 Fax: +44 01344 873173

BIODEPTH web site:

BIODEPTH Results and Relevance web site
Results and Relevance is a web resource aimed at non-specialists wanting information explaining biodiversity and ecosystem functioning and the undertaking of BIODEPTH - now that the project is completed and the results and policy implications are becoming evident.

Notes to Editors

1. The research is reported in the article "Plant Diversity and Productivity Experiments in European Grasslands" by A. Hector et al. published in the peer-reviewed journal, Science Vol. 286 Issue 5442 on Friday 5 November 1999.


At eight European fieldsites, the impact of loss of plant diversity on primary productivity was simulated by synthesizing grassland communities with different numbers of plant species. Results differed in detail at each location but there was an overall log-linear reduction of average aboveground biomass with loss of species. For a given number of species, communities with fewer functional groups were less productive. These diversity effects occurred along with differences associated with geographic location and species composition. Niche complementarity and positive species interactions appear to play a role in generating within-site diversity-productivity relationships in addition to sampling from the species pool.

AUTHORS A. Hector,1* B. Schmid,2 C. Beierkuhnlein,3 M. C. Caldeira,4 M. Diemer,2 P. G. Dimitrakopoulos,5 J.A. Finn,6 H. Freitas,4 ! P. S. Giller,6 J. Good,6 R. Harris,6 P. Högberg,7 K. Huss-Danell,8 J. Joshi,2 A. Jumpponen,6,8 C. Körner,9 P. W. Leadley,9 § M. Loreau,10 A. Minns,1 C. P. H. Mulder,6,8¦ G. ODonovan,6 S. J. Otway,1 J. S. Pereira,4 A. Prinz,3 D. J. Read,11 M. Scherer-Lorenzen,12 E-D. Schulze,12 A-S. D. Siamantziouras,5 E. Spehn,9 A. C. Terry,11 A. Y. Troumbis,5 F. I. Woodward,11 S. Yachi,10 # J. H. Lawton1.

1NERC Centre for Population Biology, Imperial College, London. 2Institute für Umweltwissenschaften, Universitåt Zurich. 3Lehrstuhl Biogeographie, Universität Bayreuth. 4Departmentos de Engenharia Florestal e de Botânica, Universidade Tecnica de Lisboa. 5Biodiversity Conservation Laboratory, University of the Aegean, Lesbos. 6Department of Zoology and Animal Ecology, University College Cork. 7Department of Forest Ecology & 8Department of Agricultural Research for Northern Sweden, Swedish University of Agricultural Sciences, Umeå. 9Institute of Botany, University of Basel. 10Laboratoire d'Ecologie, Ecole Normale Supérieure, Paris. 11Department of Animal and Plant Sciences, University of Sheffield. 12Max-Planck-Institute for Biogeochemistry, Jena.

2. The lead scientist on BIODEPTH, and former director of the Centre for Population Biology, Professor John Lawton CBE FRS took up his appointment as Chief Executive of the Natural Environment Research Council (NERC) (8) on 1 October 1999.

3. BIODEPTH (Biodiversity and Ecological Processes in Terrestrial Herbaceous Ecosystems) was funded by the EC Framework IV Environment and Climate Programme from 1996 to 1999 (contract ENV-CT95-0008).

4. A key result from the Science paper is the overall general reduction of harvest yield as species richness declines. The points on the graph represent data collected from BIODEPTH's 480 experimental plots and the lines are results of the statistical analysis that describes the best overall pattern.

5. Types of plants refers to the functional group' classification used by ecologists. In this research, three different functional groups were represented: grasses, nitrogen-fixing legumes, and non nitrogen-fixing herbs.

6. BIODEPTH field sites are in Bayreuth, Germany; Lisbon, Portugal; Lupsingen, Switzerland, Lesbos, Greece; Cork, Ireland; Umea, Sweden; and Sheffield and Ascot in the UK. The project consortium includes a mathematical modelling group in Paris, France.

7. The Centre for Population Biology, established in 1989, is funded by the UK Natural Environment Research Council (NERC), and is hosted by Imperial College where it is part of the Department of Biology on its Silwood Park campus. It publishes about 90 papers per year and its core mission is to conduct basic research in population biology and related disciplines to understand and predict the functioning of ecosystems. The CPB receives £1.1 million core funding per year.

8. The Natural Environment Research Council (NERC) is the UK´s leading body for research, survey, monitoring and training in the environmental sciences. It sponsors research and postgraduate training in universities, and has a network of Centres and Surveys across the UK. For more information, visit their web site at

9. Imperial College of Science, Technology and Medicine is the largest applied science and technology university institution in the UK, with the largest annual turnover (£310 million in 1997-98) and the largest research income (£210 million in 1997-98). It is consistently rated in the top three UK university institutions for research quality, with an aggregate score of 6.09 out of 7 in the 1996 Research Assessment Exercise. Web site at