RESTORATION OF LANDSCAPE STRUCTURE ALTERED BY FIRE SUPPRESSION

There is increasing interest in applying landscape ecological research to the management of wildlands, particularly regarding the negative e ffects of fragmentation and the benefits of corridors. Patch-producing large disturbances, such as fires and floods, produce a spatial mosai c structure in landscapes to which many species are sensitive. Managem ent of the spatial structure of the patch mosaic has seldom been an ex plicit concern, however, in part because of insufficient knowledge abo ut how this spatial structure is affected by alterations in the distur bance regime. Yet the patch mosaic structure of many landscapes has be en altered by disturbance control (such as fire suppression), and ther e is substantial interest in restoring natural disturbance regimes in some wildland landscapes. It has been proposed that, in landscapes sub jected to decades of fire suppression, simple reinstatement of the nat ural fire regime may lead to adverse effects because fuel buildup duri ng fire suppression may result in unusually large fires. It has also b een proposed that the use of small prescribed fires may be an effectiv e approach to restoration of landscapes subjected to fire suppression. Here I use a spatial GIS-based simulation model to analyze the effect s of reinstating a natural fire regime in the Boundary Waters Canoe Ar ea, Minnesota, after 82 years of fire suppression. The simulation expe riment suggests that suppression can be expected to significantly alte r landscape structure, but landscape structure can generally be restor ed within 50-75 years by reinstating the natural fire regime. Unusuall y large fires would probably hasten the restoration of landscape struc ture, while small prescribed fires will not restore the landscape but instead will produce further alteration.