Post-harvest mortality in selection-managed northern hardwoods: Dendrochronological analysis and potential long-term impacts on species composition

Background/Question/Methods Selection management, which maintains an uneven-aged stand structure and high canopy cover, has been promoted as an ecologically sustainable form of forest management. However, declines in less shade-tolerant tree species have been widely noted in selection-managed stands. One mechanism that may alter species composition in selection-managed stands is differential sensitivity of trees to post-harvest mortality. We used dendrochronological sampling of dead trees across a replicated chronosequence of harvested stands to quantify patterns of post-harvest mortality. We then simulated the impact of harvesting on stand development, using the observed post-harvest mortality rates and the SORTIE/ND individual-based modeling platform.

Results/Conclusions A subset of mid-tolerant tree species, in particular birch species, were particularly susceptible to elevated post-harvest mortality. Simulations suggest that post-harvest mortality can contribute substantially to changes in species composition in managed stands. Establishment of non-harvested retention areas within selection-managed stands may be a viable approach to mitigating losses of desired tree species and biodiversity in managed stands.