Effects of harvesting regimes on carbon and nitrogen dynamics of boreal forests in central Canada: a process model simulation

The effects of different harvesting intensities and rotation lengths on the long-term carbon (C) and nitrogen (N) dynamics of boreal forests in central Canada were simulated using the process-based ecosystem model CENTURY 4.0. Three harvesting intensities and four rotation lengths were investigated. Results suggest that intensive harvesting regimes (e.g. whole-tree harvesting (WTH)) would decrease total ecosystem C, soil C storage, and N availability, compared with conventional harvesting (CH). Harvested biomass would increase with increasing harvesting intensity. Net loss of forest productivity (indicated by above-ground biomass) would be higher in higher productivity stands in the low boreal ecoclimatic region. For a given harvesting intensity, total ecosystem C stock and N availability would be highest with long rotations (120 years) and reduced under shorter rotations (60 and 30 year). Extremely short rotations (i.e. 30 year) would reduce boreal forest productivity by as much as 65%. Longer rotations and less intensive harvesting could increase C sequestration about 36-40% in the boreal forest region of central Canada. (C) 2002 Elsevier Science B.V. All rights reserved.