Trends in post-disturbance recovery rates of Canada’s forests following wildfire and harvest

Abstract

The recovery of forests following stand-replacing disturbance is of widespread interest; however, there is both a lack of definitional clarity for the term “recovery” and a dearth of empirical data on the rates of forest recovery associated with different disturbance types. We conducted a quantitative review of literature to determine recovery times following wildfire and timber harvest and to evaluate variation in recovery rates across Canada’s diverse forest ecosystems. Recovery was assessed according to the rate of change associated with certain forest structural attributes that have traditionally been used as indicators of forest growth and productivity. The recovery of forest canopy cover, tree height, and stand basal area varied at rates that depended on disturbance type, forest biome, and ecozone. We found that, on average, it took 5–10years, depending on factors such as location and species, for most forest ecosystems of Canada to attain a benchmark canopy cover of 10% after wildfire or harvest. Similarly, regenerating stands in Canada’s boreal forests were capable of attaining average heights of 5m within five to ten years after wildfire or harvest. Stands in the Boreal Plains ecozone post-harvest reached stand basal area, benchmarked at 10m2ha−1, faster than those in the Boreal Shield, attributable to differences in tree species composition and the rich mineral deposits of the Boreal Plains. Overall, recovery of canopy cover, tree height, and stand basal area was similar or more rapid following wildfire than harvest. Our review provides temporal benchmarks for gauging recovery times after disturbance. Building upon these temporal benchmarks, and conditioned by disturbance type, site conditions, and location, we present opportunities for using dense time series of remotely sensed data to inform on regional and national trends in forest recovery following disturbance.