Short-term effects of cut-to-length versus full-tree harvesting on conifer regeneration in jack pine, mixedwood, and black spruce forests in Manitoba

Abstract

This study compares the effects of full-tree versus cut-to-length forest harvesting methods on tree regeneration in jack pine (Pinus banksiana Lamb.), mixedwood (Picea glauca (Moench) Voss – Populus tremuloides Michx. – Abies balsamea (L.) Mill.), and black spruce (Picea mariana (Mill.) BSP) sites in southeastern Manitoba, Canada. We surveyed tree regeneration densities, disturbance characteristics, and understorey vegetation in replicated control and harvested plots in each site type preharvest (1993) and 1 and 3 years postharvest (1994, 1996). In jack pine sites, the full-tree harvest method promoted regeneration of Pinus banksiana through increased disturbance of soil and the moss layer, and decreased slash deposition relative to the cut-to-length method. Conversely, in mixedwood sites the cut-to-length method resulted in less damage to advance regeneration and proved better at promoting postharvest regeneration of Abies balsamea and Picea glauca relative to the full-tree method. In black spruce sites, there were few differences in the impact of the two harvesting methods on regeneration of Picea mariana, which increased in frequency and density after both types of harvesting.