PLANT ECOLOGY TEXTBOOKS: A NEW CONTENDER'

In their new text, The Ecology of Plants, Gurevitch et al. have produced a unique and valuable resource for plant ecologists. As a tool for teaching, this book is an improvement over existing plant ecology texts, due to its comprehensive scope, its rich illustration, and the level at which material is presented. The Ecology of Plants covers ecophysiology, soils, evolution, population biology, life history, community structure and dynamics, ecosystems, landscapes, climate, biomes, paleoecology, and global change. As we present in detail below, the primary weakness of the text is its organization. However, because of its strengths, this text is in use at the University of Montana as we write and will be used by some or all of us in the future. Below we have organized our detailed comments and opinion on The Ecology of Plants by the order of the general sections used by the authors. Gurevitch et al. begin with a short chapter on ecology as a science. This section will be appreciated by those teaching at the undergraduate level in particular. The presentation is clear, the authors do not fall into the trap of Popperian dogmatism, nor do they simply insist that ecology is more than environmentalism. Instead, we are provided with a broad perspective on scientific epistemology, the value of experimentation, and a brief history of ecology. This is a nice opening to the section that follows, although the leap from Darwin and Haeckel to John Harper left some of us wondering where Warming, Schimper, Clements, and Gleason had been placed. We found Clements and Gleason in wonderful detail in Chapter 12. The first meaty section is the unit titled "The Individual and its Environment." This section deals with aspects of plant physiological ecology and is divided into chapters on light and photosynthesis, water relations and energy balance, and soils, mineral nutrition, and belowground interactions. Within each chapter, the authors chose a traditional descriptive approach in which a great deal of useful information is provided. However, we thought that a more contemporary approach, perhaps emphasizing how plant physiological responses under different environments relate to overall plant strategies within population, community, and ecosystem contexts might be more beneficial for students of plant ecology. Overall, there is a lack of conceptual integration in this section of the book, and the information does not always follow the most logical structure. There is also little emphasis on the integration of responses at different time (from short-term to evolutionary responses) and spatial scales (from cells to entire plant responses). The student ends up with an excellent source of ecophysiological information, but little appreciation that plants deal with numerous physiological and biophysical constraints that impose important trade-offs that prevent plants from excelling in each of their main functional outcomes (e.g., growth, stress tolerance, defense against consumers, reproduction). There is little development in this unit of the historical progression of the field, and there is insufficient reference to classical work. Given the traditional approach taken by the authors in Part I, it is surprising that there is no stand-alone treatment of plant responses to temperature (there's a little in Chapter 22). After all, temperature and water availability are the two most influential factors on productivity and distribution. While the authors include an energy balance section within the water relations chapter, there is no mention of responses to low and high temperature. We thought that an initial section on energy would have provided a stronger general framework for the following sections on carbon, water, and nutrient relations. This organization would also emphasize the role of plants as primary drivers of energy flow within ecosystems and provide a clear tie to Parts IV and V. Chapter 2, "Photosynthesis and the Light Environment," oes not emphasize the concept that assimilated carbon is partitioned into many competing functions and that overall carbon allocation strategies have important consequences on productivity, growth rates, reproductive potential, stress tolerance, and competitive interactions. While not crucial, this omission is likely to cause physiology-challenged ecologists a little reorganizational heartburn. Without reorganization, students may not fully appreciate that overall biomass accumulation may be substantially limited by respiration costs, which in turn are regulated by growth and allocation strategies as well as the environment (e.g., temperature). A more comprehensive chapter on carbon relations would provide this perspective. As it is, the chapter quickly moves to explanations of the light and dark reactions of photosynthesis without providing an overall conceptual overview of the function of these two important phases and their interdependence from the onset. While there is substantial detail on light harvesting, the conceptual understanding of how solar energy is used to synthesize ATP in the chloroplast is not clear (Fig. 2.2 may be misleading). The dark reactions are described in one short paragraph with no mention on how the products of the light reactions are used in the dark reactions. There is no mention at this point that actual carbon "fixation" and reduction occur during this phase. This is unfortunate as it is this initial reduction by plants that allows energy transfer through trophic levels within ecosystems. The dual affinity of rubisco to CO, and 02 and the consequent photorespiratory cycle are not brought up until the discussion on photosynthetic pathways. Adding to the organizational conThe ecology of plants. Jessica Gurevitch, Samuel M. Scheiner, and Gordon