Above- and belowground carbon stocks under differing silvicultural scenarios

Despite the need for climate change mitigation and altered forest management practices, little is known about the impacts of silvicultural practices such as partial-cuts and clear-cuts on forest ecosystem carbon (C) dynamics. Specifically, the effect of these two overstory treatments on C pools other than the aboveground biomass of trees remains poorly understood. Here, C stocks were estimated for a northern temperate mixed forest located in eastern Québec, Canada, five years after clear-cutting and partial-cutting, either with or without a brushing treatment to control the competing vegetation. The biomass of the aboveground vegetation (trees, saplings, understory), litter and woody debris (coarse, small, fine), as well as the roots (diameter ≤ 1.5 cm) was evaluated. Additionally, soil C pools up to a depth of 35 cm of the mineral soil were assessed. Total ecosystem C stocks were influenced by the overstory treatments reflecting harvest intensities. Although the belowground C pools were major contributors to total ecosystem C stocks, silvicultural treatments only influenced forest floor and aboveground C stocks. However, assessments like the one presented here capture contemporary C stocks, which highlights the need for monitoring to build suitable forest ecosystem C models and to understand long-term C dynamics.