MANAGING THE PATTERN OF FOREST HARVEST - LESSONS FROM WILDFIRE

Managing forests for sustainable use requires that both the biological diversity of the forests and a viable forest industry be maintained. A current approach towards maintaining biological diversity is to patt ern forest management practices after those of natural disturbance eve nts. This paradigm hypothesizes that ecological processes will be main tained best where active management approximates natural disturbance e vents. The forest management model now used in most sub-boreal and bor eal forests calls for regularly dispersed clearcuts no greater than 60 -100 ha in size. However, the spatial characteristics of the landscape produced by this model are distinctly different from the historic pat tern generated by wildfire, which was heretofore the dominant stand-re placing process in these forests. Wildfire creates a more complex land scape spatial pattern with greater range in patch size and more irregu lar disturbance boundaries. Individual wildfires are often over 500 ha put leave patches of unburned forest within them. The combination of these attributes is not present in recent clearcuts. Allowing a propor tion of larger (i.e. >500 ha) harvest units may provide distinct econo mic advantages that could outweigh the opportunity costs of leaving so me patches of forest behind. For the forest type examined, further eva luation of modelling forest harvest patterns more closely after the pa tterns created by wildfire is required as it may achieve a good balanc e and strike a suitable compromise between certain ecological and econ omic objectives of sustainable development.