Evolutionary ecology of plant–plant interactions: an empirical modelling approach

Abstract

Review by MOH:- The subtitle is 'An empirical modelling approach'. By this, the author means that he uses phenomenological plant models fitted to plant growth data in a statistical sense. Empirical models rely heavily on data, and will never be better than the observations on which they are based. Mechanistic plant models, by contrast, relate growth rates to limiting resources. Such models contain many parameters that are difficult or impossible to estimate jointly, and are therefore almost always somewhat theoretical and unsuited to making predictions. Even empirical models need a fair number of parameters. Twenty-five parameters used in chapters 2-4 are listed in Appendix A (p. 115). These include plant size, competitive neighbourhood function, the parameter that determines the location of the inflection point in the Richards growth model, the per capita competition coefficient of species j on i, and the degree of size-asymmetric growth. Asymmetry is a major feature of plant competition, and is one of the many consequences of being sedentary. Indeed, the demands of a sedentary life with a requirement for light are the basis of the struggle for existence in plants. Despite its title, most of the book is about ecological models that are not evolutionary. When, for example, models of competition between two genotypes of Arabidopsis thaliana are considered, it is with the premise that A. thaliana is an almost completely self-fertilizing winter annual. Genetics and evolution appear only in chapters 5 and 6, and are not strongly related to the ecological models appearing earlier. Evolutionary topics such as the evolution of sex and of the selfing rate are rather briefly reviewed. Finally, the subject of speciation is discussed in two pages. Because of these features and also because mathematical notation is rather prominent, this is not a book for the average plant ecologist. However, for those wanting a thoughtful introduction to the literature on growth and competition, it provides a useful review of the field.