The effects of salvage logging on timber supply and wildlife habitat.

摘要

Fire is an important natural disturbance agent in the boreal forest of Alberta. The most conspicuous result after fires is the large number of standing dead and dying trees. Salvage logging is conducted to minimize timber losses caused by fires. However, burned trees perform vital functions in forested ecosystems, such as providing habitat for wildlife. In Alberta, there are few explicit policies on salvage logging. The objective of this study was to evaluate salvage logging thresholds and develop tradeoffs between timber supply and wildlife habitat areas under different salvage scenarios. A Monte Carlo simulation of forest fire and an optimization-based forest harvesting model were used to project annual allowable cuts, net present values, and habitat areas over 200 years. Results showed the probability distributions of projected outcomes, which could be used to help determine the appropriate salvage rate.; In order to simulate salvage logging spatially, a spatially explicit fire model is necessary. A simple spatial fire model was developed to simulate the spread of wildfire at large spatial and temporal extents by using a cellular automaton approach. The model presented the landscape as a hexagonal-based lattice and as a square-based lattice with a 3 ha resolution, and compared the performance of fire spread with the hexagonal and the square models. The spread probability of a fire was modified from the annual burn rate of each fuel type. Results showed that both hexagonal and square models could represent well fire size distributions and annual burned areas, but the hexagonal model simulated fire patterns and fire skips more naturally than the square model.