Studying the impacts of harvest intensity on site productivity of Ontario's black spruce ecosystems

Abstract

As a result of a Class Environmental Assessment, the Ontario Ministry of Natural Resources (OMNR) was mandated to design and implement a research project pertaining to the effects of full-tree harvesting on long-term site productivity. This project, initiated in 1991, was designed to focus on ecosystem processes and the changes occurring to these processes after harvesting (e.g., quantifying the disruption and recovery) for the black spruce working group. A series of replicated, experimental harvest treatments with varying degrees of biomass removal were conducted on nine core study sites, representing different black spruce ecosites located in northwestern Ontario, Canada. The harvest treatments included: uncut — controls, tree length — delimbed at the stump, full tree — delimbed at the roadside, full-tree chipping — chipped debris was returned to the harvest plot, and whole tree — complete removal of vegetation and forest floor. Each site consisted of 16 plots, three replicates of the four harvest treatments (30 m × 30 m plots) and four replicates of the control plots (50 m × 50 m plots). Work on this project is anticipated to continue for a minimum of fifteen years to detail the early and most dynamic stages of post-harvest recovery. Key words: black spruce, site productivity, nutrient cycling, harvesting impacts