The Ecology and Evolution of Clonal Plants - Review

Ecology, Jan, 1999 by Brian C. McCarthy

de Kroon, Hans, and Jan van Groenendael, editors. 1997. Backhuys, Leiden, The Netherlands. xii 453 p. $67.00, ISBN: 90-7334873-0.

Pioneering field studies in the 1970s and early 1980s set the stage for two important conferences concerning clonal plant biology. These conferences were ultimately summarized in printed form in the mid-1980s and became mainstay references for those interested in the ecology and evolution of clonal plants (Jackson, J. B.C., L. W. Buss, and R. E. Cook. 1985. Population biology and evolution of clonal organisms, Yale University Press, New Haven; and Harper, J. L., B. R. Rosen, and J. White. 1986. The growth and form of modular organisms. The Royal Society, London, United Kingdom). These works stimulated considerable research interest, subsequent symposia and conferences, and essentially served as a research agenda for the next decade.

The ecology and evolution of clonal plants represents the most contemporary treatment which attempts to bring together in one volume an overview of the recent theoretical and empirical developments in clonal plant biology. However, the present text differs fundamentally from previous works in that it is not the proceedings of a conference, but, rather an attempt to review the existing published literature. Moreover, the text treats various plant life forms (mosses to trees) and explores patterns (temporal and spatial distribution) and processes (selection and competition) throughout the biological hierarchy (individuals to communities). This breadth of coverage will be most useful to those entering clonal plant research. In the preface, the editors (de Kroon and van Groenendael) acknowledge that we are beginning to obtain a reasonably clear picture of the ecology, physiology, and genetics of clonal plants, but that the integration of this information across taxonomic and organizational boundaries remains as one of the great challenges facing us in years ahead.

Multi-authored collections of papers are notoriously difficult to review. There are 40 authors and 18 contributed papers. There are markedly different writing styles and standards. The editors provided some very useful background information in the preface which helped to set the stage for the overall text. They also provided reasonably helpful taxonomic and subject indices for the entire volume. A glossary of terms was a nice touch, particularly for students who may be unfamiliar with certain terminology or for those who are not botanists. The editors have loosely arranged the contributions along a hierarchical scale from low to high integration. While this may be the best that can be done with a diverse group of contributors, I would have preferred to see explicit subsections and more detailed prefaces to each. As it stands, the organization and logical development of the overall text is a bit obtuse. Certainly many of the individual papers represent excellent contributions in their own right.

Despite the fact that little substantive information can be provided about each contribution, I will highlight the overall topic or idea posed in each paper because it provides a useful perspective as to the overall content of the volume. The first chapter, by Klimes et al., explores the distribution and abundance patterns of clonal plant traits across habitats and vegetation types. The next few chapters (Watson et al., Sachs and Novoplansky, Marshall and Price) are organism-based and focus primarily on the developmental and structural organization of clonal plants. The theme of sectoriality, integration, and translocation is continued in the next two chapters (Jonsdottir and Watson, Alpert and Stuefer). Oborny and Cain then review models of the spatial spread and foraging of clonal plant species and propose areas for future work and development. Subsequently, the theme turns to one of a more genetical or evolutionary nature. McLellan et al. review the molecular and quantitative variation of clonal plants, and are followed by a collection of essays on clonal life histories and patterns of seedling establishment (Eriksson), somatic mutation (Klekowski), and models of hierarchical selection (Vuorisalo et al.). The taxonomic diversity of clonality is explored via the inclusion of chapters specifically on clonality in trees (Peterson and Jones) and bryophytes (van der Hoeven and During) as well as discussions of the roles of intra- and interspecific competition. Competition continues as an organizing thread for much of the remainder of the text. Suzuki and Hutchings review intraclonal density regulation. Herben and Hara evaluate the effects of spatial patterning in determining the role of clonality in community dynamics. de Kroon and Bobbink specifically address how atmospheric nitrogen deposition may positively affect clonal plant dominance in certain communities. The final two chapters scale up to a global perspective and evaluate the role of clonality in mediating global climate change (Callaghan et al.) and how clonality may influence plant invasions throughout the biosphere (Pysek).