Methods in Comparative Plant Ecology: A Laboratory Manual

Ecology, Jan, 1995 by Arnold van der Valk

The standardized methods developed for the Integrated Screening Program of the NERC Unit for Comparative Plant Ecology are presented in this manual. They are the methods that will provide the precise measurements of plant characteristics and growth that are needed to make plant ecology a predictive science. How these data can be used to search for generalities that are ecologically relevant is, not surprisingly, largely ignored in this methods manual, although not completely. To understand the theoretical framework for the comparative approach, J. P. Grime's Plant strategies and vegetation processes (1979. Wiley and Sons, New York) is essential reading. The Integrated Screening Program is a laboratory approach. In other words, measurements are made on plants kept under specified environmental conditions in growth chambers. The methods presented have been developed and tested primarily on terrestrial plants from the European temperate zone. The applicability of some of these methods to tropical or subtropical floras is problematic, as the editors acknowledge, as is their application to aquatic floras. Nevertheless, the majority of the proposed methods can be used without any adaptation, or with only minimal adaptation, to much of the world's flora, particularly fast growing herbaceous plants.

This book is divided into five chapters. The first chapter by Hendry and Grime provides a brief overview of the Integrated Screening Programme and outlines the organization of the rest of the manual. Chapter two outlines general procedures and methods used in the Integrated Screening Program. It covers seed collection and storage, seed germination, standard aerial and soil environmental conditions used in screening studies, and plant harvesting techniques. The standard environmental regime is summarized on less than one page at the end of this chapter. For plant ecologists outside of Europe, duplicating the standard regime will be difficult. For example, I would be hard pressed to find locally any washed silica sand from the Double Arches Pit No. 21, Leighton Buzzard, Bedfordshire, UK. Chapter three, which accounts for over 75% of the book, presents the recommended methods for measuring plant anatomy, DNA, growth, plant metabolism, mineral nutrition, leaves, roots, and shoots, as well as the impacts of various environmental conditions (e.g., anoxia, UV-B, high temperatures) and toxins (aluminum, cadmium, iron, sulphide) on plants or plant parts. Each section is written by one or more authors who are more often than not at the University of Sheffield. There are also a number of authors from other European universities and research institutes and one New Zealander, Australian, American, and Canadian to give the book a bit of an international dimension. The multivariate technique (non-hierarchical or optimal clustering) used to analyze the large volume of comparative data generated is briefly described in Chapter four. Why this technique is preferable to a host of other multivariate techniques for analyzing this kind of data is never adequately explained. The last chapter, which is only two pages long, deals very briefly with some problems and shortcomings of the Integrated Screening Program. These include applying these methods to plants with different morphologies and life spans, the lack of suitable methods that can be used to screen large number of plants for some types of measurements, and the problem of dealing with mutualistic associations such as mycorrhizae, epiphytes, and hemiparasites. The editors also provide a wish list of tests that they would have liked to include, but for which they were unable to find suitable methods. The book ends with useful species and subject indices.

There are 68 methods described in this book. A more-or-less standard format is used for each: the rationale for each method is given; procedures outlined; results from a study presented; and one or more references to the relevant literature are given. The methods, when appropriate, are illustrated with photographs and figures. The manual has been well written and edited, and the methods are usually clearly and succinctly described. To save space, each method starts right after the previous one ends. Because of the double column format, this makes it more difficult to find the start of a method than it need be. This, however, is only a minor inconvenience. The book, although it has a hard cover, is spiral bound, making it very convenient to use on a laboratory bench. Although intended primarily for researchers, this manual will be very useful for developing laboratory exercises for courses in plant ecology and plant physiological ecology and even in general ecology. Likewise, it will be very useful to beginning graduate students (and, I suspect, many of their major professors) who are looking for suitable techniques while they are developing thesis research projects. Although there are many other plant ecology technique manuals, most of them deal primarily with techniques used in either community or physiological ecology. The diverse laboratory methods covered in this manual make it a unique and valuable addition to the methods literature. You do not have to be an adherent of the comparative plant ecology school to find this book a useful addition to your bookshelf.