Impact of global change and forest management on carbon sequestration in northern forested peatlands

Abstract

Northern peatlands occupy approximately 4% of the global land surface and store about 30% of the global soil carbon (C). A compilation of C accumulation rates in northern peatlands indicated a long-term average rate of C accumulation of 24.1 g m–2 year–1. However, several studies have indicated that on a short-time scale and given the proper conditions, these ecosystems can exhibit very high rates of C accumulation (up to 425 g m–2 year–1). Peatland development is related to precipitation and temperature, and climate change is expected to have an important impact on the C balance of this ecosystem. Given the expected climate change, we suggest that most of the northern forested peatlands located in areas where precipitation is expected to increase (eastern Canada, Alaska, FSU, and Fennoscandia) will continue to act as a C sink in the future. In contrast, forested peatlands of western and central Canada, where precipitation is predicted to decrease, should have a reduction in their C sequestration rates and (or) could become a C source. These trends could be affected by forest management in forested peatlands and by changes in fire cycles. Careful logging, as opposed to wildfire, will facilitate C sequestration in forested peatlands and boreal forest stands prone to paludification while silvicultural treatments (e.g., drainage, site preparation) recommended to increase site productivity will enhance C losses from the soil, but this loss could be compensated by an increase in C storage in tree biomass.Key words: C sequestration, forested peatland, paludification, greenhouse gases, climate change, forest management.