A stochastic characterisation of the natural disturbance regime of the boreal mixedwood forest with implications for sustainable forest management

The annual area burned on an 8.6 x 10(6) ha study area in the boreal mixedw ood forest of northeastern Alberta, Canada, was characterised as a serially independent random draw from a lognormal distribution. This characterisati on was applied in Monte Carlo simulations, which showed that estimates of t he mean annual burn rates, even with long sample periods, are highly imprec ise;Monte Carlo simulation was also used to simulate the development of a f orest subject to lognormally distributed annual burn rate in an attempt to characterise the equilibrium age-class structure. No equilibrium age-class structure could be identified from the simulation results. The validity of equilibrium age-class distribution models (e.g., the negative exponential a nd Weibull) and analysis that relies on these models is questioned for fore sts where the annual burn rate is highly variable.