Prairie Wetland Ecology: The Contribution of the Marsh Ecology Research Program

Prairie Wetland Ecology: The Contribution of the Marsh Ecology Research Program
Henry R. Murkin, Arnold G. van der Valk and William R. Clark (Editors)
Ames: Iowa State University Press
Publication Date: 

cloth, 413 p., $79.95

This text is the result of a long-term study (1980-1989) of prairie wetlands in the Delta Marsh in the province of Manitoba, Canada. Although there has been much work done on various aspects of prairie wetlands over the years, this is the first study to use an integrated approach of following many aspects of this wetland community over an extended period of time. The main areas of study include hydrology, water chemistry, macrophytes, macrophyte litter, algae, invertebrates and vertebrate populations.

One of the temporal phenomena important to the ecology of prairie wetlands is the wet/dry cycle that all of these communities experience. This process of flooding and subsequent drying that occurs through the seasons or years profoundly influences the various components of the wetland community. The basis for this text was an experimental design, which used 10 contiguous experimental cells, five hectares each, and two reference cells to serve as controls. The experimental cells, which had pumps to regulate water levels, were created within a large marsh complex by means of diking; the control cells were undiked plots within the greater marsh area. The value of this design was that the researchers were able to replicate the wet/dry cycle with varying periods of wetting and drying in a relatively compressed time frame.

In terms of management implications of the Marsh Ecology Research Program, its most important contribution has been in the area of macrophyte management. Invaluable information has been provided on a variety of topics ranging from nutrient management, seed germination and distribution and hydrologic effects to seed bank manipulation and life history of wetland vegetation. One example of new information discovered in this study relates to vegetation dynamics and the formation of vegetation zones within the community. This is perhaps the only study to have examined the early stages of zone formation. The authors' work has shown that this zonation is not the result of any one overriding factor, but rather the collective result of many factors.

A valuable feature of the book is the section of each chapter on management implications and research needs. These portions of the text provide valuable information for wetland managers and research scientists alike. For example, in the chapter on "Algae in the Prairie Wetland," the management section provides information on the most desirable algae assemblage, from the standpoint of herbivores, as well as the negative effects of anthropogenic nutrient inputs. The research segment of this chapter points the researcher in the direction of looking at inland saline wetlands, the important epipelon algae of semi-dry wetlands, the need for a clearer understanding of photosynthetic parameters and several other topics.

While many studies have demonstrated the importance of the hemi-marsh phase in containing the highest diversity of organisms, Prairie Wetland Ecology, while supporting this view, has shown the much greater diversity value in maintaining the entire wet/dry cycle.

Although this publication provides a tremendous wealth of information on the dynamics of prairie wetlands, it does have some features that require serious consideration for those utilizing the results. The experimental cells in this study were created utilizing earthen dikes. As a result, there was a certain amount of seepage into and out of the cells during the experimental phase. The researchers were well aware of this factor and determined that the seepage did not have a significant impact on their results. Also, because these cells were isolated from the surrounding marsh and filled and emptied with pumps, there was a lack of fish populations within the cells. This is not only a problem for a complete understanding of plant-herbivore relations and nutrient dynamics, but it also was one condition that was significantly different from the control plots.

Prairie Wetland Ecology, while providing support for much of the wetland data that has been collected in the past, has also discovered new and important information on wetland ecology and management. And even though some features of the experimental design were "unnatural," I feel that this publication is a valuable resource and should be required reading for anyone involved in wetland restoration, creation and management.

— James Steffen, Ecologist, Chicago Botanic Garden.