Impacts of Precommercial Management on Forest Carbon Dynamics

In even-aged forestry, boreal forest sites are carbon sources for up to 10–30 years following the final cutting and regeneration (clear-cutting with planting/seeding or cutting for natural regeneration with shelterwood/seed-tree cutting), before shifting to carbon sinks. This period covers the seedling phase with increase of growth and accumulation of carbon in trees and soil, affecting the rate of the shift from a carbon source to a carbon sink. In this context, precommercial management refers to the management of seedling stands prior to commercial management. In even-aged forestry, management includes thinning and harvest of trees for timber in the period before final cutting. Precommercial management may also include cleaning, that is, the removal of trees or tree species likely to disrupt the growth of seedlings selected for future management. In precommercial management, energy biomass may be harvested, but the main objective is to control the growth and development of seedling stands for producing timber and biomass in commercial management through pole and middle-aged phases in the chronosequence.