Northern Prairie Wildlife Research Center
Throughout postglacial time, and most likely in earlier periods as well, fire has had substantial influence on life and landscape in North America. This influence has been through modification of vegetation and soils, and subsequently, on dependent fauna, water resources, microclimate, air quality, and perhaps even general climate during extreme conflagrations. Although many of the immediate effects of fire fall into the "common knowledge" category, long-term effects upon the ecosystem are less well known. Thus, although the successional stages following fire are recognized as resulting in generally predictable soil, floral, and faunal development, the exact mechanisms through which various factors affect the growth, development, range expansion, and relative dominance of both plant and animal species following fire is still an area of major study.
Only in recent decades has it become clear that both uncontrolled fire and complete fire exclusion can be detrimental to ecosystems that have developed in fire regimes different from those selected by man. Scientists have accepted the role that fire plays in both long- and short-term shaping of plant communities and their associated fauna. Many, however, still regard fire as completely destructive, a view that is not surprising considering the scale and frequency of major conflagrations that have occurred in North America since the arrival of European man. [An excellent review of man's view of fire is provided by S. J. Pyne (1982; Fire in America-a cultural history of wildland and rural fire. Princeton University Press, Princeton, NJ. 654 pp.). Similarly, Higgins (1986)(See note below) provides a review of aboriginal fire in North American prairies.]
Fire affects the interdependent components of the ecosystem simultaneously with the result that synergistic interactions are easily identified at all levels of investigation.
Although this is clearly recognized, investigators and managers often wish to know the details of the effects of fire (both harmful and beneficial) on identifiable portions of the ecosystem. In response, several major reviews (Ahlgren and Ahlgren 1960; Kozlowski and Ahlgren 1974; Lyon et al. 1978; Martin et al. 1979; Tiedemann et al. 1979; Wells et al. 1979; Sandburg et al. 1980; Lotan et al. 1981; Wright and Bailey 1982) have compiled information on the effect of fire on individual plant communities, groups of organisms, and physical aspects of the environment. This material leads to the inescapable conclusion that studies of the interaction of any terrestrial and many aquatic organisms with their environment are incomplete if fire effects are not taken into account.
In contrast to a wealth of data on the effects of fire in grasslands, shrublands, forests, and other terrestrial habitats, the information on the effects of fire upon wetlands is sparse, scattered throughout the literature, and lacks a comprehensive synthesis. Thus, although one may find reviews of the effects of fire upon watersheds as a whole, or streams, rivers, or lakes as a whole, the effects of fire upon wetland vegetation and wetland wildlife have, for the most part, been restricted to site-specific studies. This is not to say, however, that fire is an unused tool in wetlands management or that fire effects in wetland habitats are completely unknown. In fact, quite the contrary is true for fire has long been used to control wetland succession in coastal marshes, is a recognized tool for control of undesirable or noxious wetland plants in both coastal and inland wetlands, and its effects upon both permafrost areas and peatlands in general have long been appreciated. Nonetheless, Trippensee's (1953) classic Wildlife Management (Vol. 2) only briefly mentioned fire as a management tool of positive value, reflecting the extreme emphasis of the time on fire suppression. Slightly more recent U.S. Government documents (Martin et al. 1957; Davison and Neely 1959) from the Departments of Interior and Agriculture, respectively, emphasized the necessity to use fire in management of wetlands, even though only general prescriptions could be provided. Contemporary wetland management "handbooks" such as those written by Linde (1969) and Schnick et al. (1982) provide, at best, slight expansions upon earlier general advice, with fire recognized as being of value, but with the authors providing only general management advice from a few site-specific studies to guide the wetlands manager. Not until Linde's (1985) review was an integrated assessment of a number of wetland management techniques, including fire, presented, but the prescriptions were limited in universal application by the specific focus on man-made impoundments in the Great Lakes States. Linde's (1985) discussion reiterated, with more detail, the advice available in Martin et al. (1957) and Davison and Neely (1959), indicating only slight progress. Thus, throughout, one finds substantially less rigor in evaluation of fire-wetlands relations than one finds in modern texts on range management, or management of species of commercially important trees, indicating the need for further research and synthesis (cf Kantrud 1986).
Why an emphasis upon fire and its effects upon wetlands? One reason is that wetlands and other aquatic habitats make up more than 13.8 million ha (34 million acres) approximately 38%, of the National Wildlife Refuge System. But perhaps the best answer is indicated within the recent review of wetland trends in the United States (W. E. Frayer et al 1983; Status and trends of wetlands and deepwater habitats in the conterminous United States, 1950's to 1970's. Department of Forestry and Range Science, Colorado State University, Fort Collins. 32 pp.) which showed a net wetland and deepwater habitat loss of 1.25 million ha for the period, and an average annual net loss of 154 thousand ha. Despite the formation of new lacustrine deepwater habitats (lakes), palustrine open water (ponds), and estuarine subtidal deepwater habitats (bay bottoms), the wetland base of the United States nonetheless decreased from 43.7 million ha in the 1950's to 40.1 million ha in the 1970's, a net loss of 3.6 million ha of inland and coastal wetlands. In terms of what was once available as wetland habitat, probably less than 46% remains of the original 87 million ha in the conterminous United States (R. W. Tiner, Jr. 1984. Wetlands of the United States: current status and recent trends. U.S. Fish and Wildl. Serv., National Wetlands Inventory, USGPO, Washington, DC 59pp. ) These figures make clear both the substantial current loss and the continuing trends in wetland areal loss in the United States.
As more information on the value of wetlands has accumulated, the value of each remaining wetland (as the total wetland base shrinks) has become relatively greater. Thus, there is an ever-greater need for natural resources managers to use every tool at their disposal to efficiently and effectively manage wetlands for a multitude of human and wildlife benefits. This is especially true of the Fish and Wildlife Service, whose responsibility for managing wetlands comes largely from international treaties concerning migratory birds, the Federal Government's Fish and Wildlife Coordination Act, the Service's role as a reviewer of Federal projects and applications for Federal permits that require wetland alteration, the Endangered Species Act of 1973, and the National Environmental Policy Act of 1969.
Wetland management as a whole is poorly founded in theory and as a predictive science (M. W. Weller. 1978. Management of freshwater marshes for wildlife. Pages 267-284 in R. E. Good et al., eds. Freshwater wetlands, ecological processes and management potential. Academic Press, New York). This is especially true with regard to use of fire as a management tool in wetlands, largely because so little work that is of a specifically comparative nature or that strictly tests hypotheses has been conducted. [M. W. Weller (ibid) specifically suggested that burning and grazing were wetland management practices most in need of study.] This does not mean, however, that general guidelines cannot be obtained from the literature, or that guidance on both best management practices for various wetland types and areas in need of further research is totally lacking. A surprising amount of information on fire-wetlands relationships is available. The interested manager will find a wealth of material pertinent to wetland management and fire management planning in the following bibliography.
(NOTE: Citations referenced here and follow Unlike the literature on fire in terrestrialing with surnames and dates are included in the annotated bibliography.)