Natural disturbance regime as the basis of forest conservation and ecosystem management

Abstract

Forest disturbance regime, i.e. the spatio-temporal occurrence pattern of varied disturbances in a given area, is a key factor shaping forest ecosystem structure, species assemblages and processes. Over the past decades, natural disturbance emulation (NDE), based on adapted silviculture for maintaining habitat diversity, has been proposed as a comprehensive approach to forest conservation and ecosystem management. The logic here is that by restoring and maintaining forest structures that are sufficiently similar to those occurring in natural forests, it would be possible to reduce the adverse effects of timber harvesting on biodiversity and key ecological processes. Despite the NDE initiatives, boreal forestry continues to favor clear cut harvesting and even-aged management, an approach that is known to match poorly with natural forest structure and dynamics. Due to intensifying forest utilization, and in some areas due to increasing natural disturbances with warming climate, boreal forest age class structures have changed, and continue to change, rapidly so that the proportion of old forest has substantially declined, while that of young post-harvest and/or post-natural-disturbance forests have increased. To mitigate the risks to boreal forest biodiversity and ecosystem functioning, and to safeguard the multiple services forests provide to societies, more attention is required on maintaining an adequate share and ecological qualities of young post-disturbance stages, as well as mature forest stages with old-growth characteristics. This can be accomplished by following natural disturbance emulation principles, i.e. managing for natural post-disturbance legacy structures in forest harvesting, and by innovative use of mixtures of silvicultural approaches to maintain variability and critical proportions of late-successional forest in landscapes.

1) Kuuluvainen, T. 2016. Ecosystem management of the boreal forest. Oxford Research Encyclopedia of Environmental Sciences. Oxford University Press 2) Kuuluvainen, T. & Grenfell, R. 2012. Natural disturbance emulation in boreal forest ecosystem management: theories, strategies and a comparison with conventional even-aged management. Canadian Journal of Forest Research 42: 1185–1203.