Empirical knowledge of long-term ecosystem response to single and compound disturbances is essential for predicting disturbance effects and identifying management practices to maintain productive capacity of managed and restored landscapes. We report on soil, foliar nutrition, and regeneration growth response to wildfire, clearcut harvesting, and post-fire salvage-logging, as well as undisturbed control stands within the first year following disturbance and 10/11 years post-disturbance in trembling aspen-white spruce mixedwood forests near Lesser Slave Lake, north-central Alberta, Canada. The compound disturbance of salvage-logging resulted in greater long-term impacts on forest floor properties than either wildfire or harvesting alone. Changes in forest floor properties such as carbon and nitrogen pools and cation exchange capacity under salvage-logging have persisted for ten years, and exhibit a different recovery trajectory than fire or harvesting. Forest floor properties under harvesting including depth, carbon content, pH, extractable ammonium, and extractable sulphur were not different from the control condition ten years post-harvest. Effects on soil and foliar nutrition were not reflected in productivity (height and diameter) of regenerating vegetation. Our results show differences between short and long-term response to disturbance, among single natural and anthropogenic disturbances, and among single and compound disturbances.

compound disturbance, salvage logging, soil carbon, soil nutrients, Boreal Plains Ecozone, boreal mixedwood forest.