Restoring fire to ecosystems: methods vary with land management goals

Periodic forest, grassland, and shrubland fires are part of the natural environment-as natural and vital as rain, snow, or wind (Heinselman 1978). Evidence of past fires is found in charcoal layers in lakes and bogs, and in the fire-scarred cross sections of trees. Recurring disturbances by fire are essential to the functioning of many ecosystems, termed "fire-dependent, " that are found throughout North America (Heinselman 1978). Many examples are available to describe how fire affects the functioning of ecosystems, such as influencing plant succession, fuel accumulations, structure and composition of vegetation, insect and disease populations, nutrient cycling, productivity, diversity, and habitats for wildlife. Kilgore and Heinselman (1990) highlighted fire's histori-cal role as a fundamental disturbance process in their classification of "continental fire regimes. " They described a natural fire regime as the total pattern of fires over time that is characteristic of a region or ecosystem. They also defined fire regimes as to fire type and intensity, typical fire sizes and patterns, and fire frequency, or length of return intervals in years (Agee, this proceedings). The noteworthy aspect of continental fire regimes is that few plant commu-nities in North America occur where fires historically were rare or absent. In other words, most ecosystems in the United States evolved in environments where wildland fires occurred regularly, establishing fire as a process that affects many ecosystem functions. The application of prescribed fire, for many different purposes, attempts to mimic the diverse effects within the natural role of fire. However, prescribed fire has not been used on a scale adequate for sustaining the productivity of fire-dependent ecosystems. After reviewing some prescribed fire accomplishments in the United States, we will identify several pending recom-mendations that could modify the future of prescribed fire