ecological modelling 207 ( 2 0 0 7 ) 264–276 available at www.sciencedirect.com journal homepage: www.elsevier.com/locate/ecolmodel Consequences of intraspecific variation for the structure and function of ecological communities Part 1. Model development and predicted patterns of diversity James L. Bown a , Elizaveta Pachepsky a,c , Alistair Eberst a , Ursula Bausenwein b , Peter Millard b , Geoff R. Squire c , John W. Crawford a,∗ a SIMBIOS, School of Computing and Creative Technologies, University of Abertay Dundee, Bell Street, Dundee DD1 1HG, UK b Macaulay Institute, Craigiebuckler, Aberdeen AB15 8QH, UK c Scottish Crop Research Institute, Invergowrie, Dundee DD2 1RJ, UK article info Article history: Received 21 December 2005 Received in revised form 26 April 2007 Accepted 16 May 2007 Published on line 6 July 2007 Keywords: Individual-based modelling Ecosystem dynamics Community dynamics Biodiversity Trait-based modelling Trait trade-offs Intraspecific variation Interspecific variation Community structure Abundance distribution abstract Biodiversity is generally accepted to include both within species and between species vari- ation. Consequently, the contribution to the functioning of ecosystems of variation among individuals should be accounted for. However, very little is known about patterns of diver- sity below the species level, and less still about the patterns of individual diversity and their relation to ecosystem context and community function. We present a model for the dynamics of individuals that is physiologically based and spatially explicit. Individuals are defined in terms of measurable parameters that relate environmental context to phenotype and in this sense define the genotype. Estimates for the variation in the parameter values are obtained from experiments conducted on the species Rumex acetosa. Simulations are performed to predict the form of the relative abundance distribution, and the dependence of the predicted number of coexisting genotypes on patch area (the genotype–area curve). We find that the predicted forms of the abundance distribution and genotype–area curve are indistinguishable from those measured at the species level. Furthermore, we identify the importance of physiological trade-offs at the individual level in promoting diversity and the sensitivity of genotype richness to the degree of similarity of individuals in the community. The extension of the model to include inter-species variation is discussed. © 2007 Elsevier B.V. All rights reserved. 1. Introduction There exists a considerable literature based on both the struc- ture and function of biological communities, with a particular focus on exploring the link between the two, e.g. Naeem and Li (1997), Yachi and Loreau (1999), Schwartz et al. (2000) and ∗ Corresponding author. E-mail address: J.Crawford@simbios.ac.uk (J.W. Crawford). Mouquet et al. (2002). In spite of a considerable effort to seek general relations between species richness and function, e.g. productivity, no such generalisations have been found and it is now believed that such relations, if they exist, depend on the phenotypic response of species to different environmental contexts (Mouquet et al., 2002). These findings acknowledge 0304-3800/$ – see front matter © 2007 Elsevier B.V. All rights reserved. doi:10.1016/j.ecolmodel.2007.05.004