White Rose University Consortium logo
University of Leeds logo University of Sheffield logo York University logo

Biodiversity at the edge: A test of the importance of spatial "mass effects" in the Rothamsted Park Grass experiments

Kunin, W.E. (1998) Biodiversity at the edge: A test of the importance of spatial "mass effects" in the Rothamsted Park Grass experiments. Proceedings of the National Academy of Sciences, 95 (1). pp. 207-212. ISSN 0027-8424

Available under licence : See the attached licence file.

Download (144Kb)


The coexistence of many plant species competing for a few resources is one of the central puzzles of community ecology. One explanation is that different species may be competitively superior in different microhabitats. Many species could then coexist within each piece of a mosaic landscape by what has been termed "mass effects," because subpopulations in areas with negative growth rates would be supplemented by propagules from areas with reproductive surpluses. If mass effects are important, plant species diversity should increase near habitat boundaries, especially where habitat differences are moderate. In the first experimental test of this prediction, plants were censused on 54 transects within the long-established Rothamsted Park Grass plots. Very few showed significant declines in species richness with distance from subplot boundaries. Nonetheless, the regression coefficients were negative much more often than expected by chance, suggesting that weak mass effects operated. The effect was strongest where neighboring subplots differed greatly, with no evidence of the predicted decline where differences were extreme. Detailed analyses of transects with apparent mass effects revealed few species that behaved as predicted. This study serves both to provide evidence of the existence of mass effects and to question their importance in the maintenance of local plant diversity in this system.

Item Type: Article
Copyright, Publisher and Additional Information: Copyright © 1998 by The National Academy of Sciences
Institution: The University of Leeds
Academic Units: The University of Leeds > Faculty of Biological Sciences (Leeds) > Institute of Integrative and Comparative Biology (Leeds)
Depositing User: Sherpa Assistant
Date Deposited: 14 Mar 2006
Last Modified: 14 Jun 2014 11:21
Published Version: http://www.pnas.org/cgi/content/full/95/1/207
Status: Published
Refereed: Yes
URI: http://eprints.whiterose.ac.uk/id/eprint/560

Actions (repository staff only: login required)