Growth and productivity of the moss <i>Sphagnum fuscum</i> in bogs of northeastern North America

Peatlands store about one-third of the global soil carbon pool. Improved understanding of drivers of Sphagnum productivity can improve models of carbon dynamics under future climate regimes. Studies of Sphagnum growth were undertaken to investigate rates of Sphagnum growth and productivity for ombrotrophic bogs across eastern North America. Growth of Sphagnum fuscum was measured at eight bogs along a transect from Newfoundland to Minnesota between 1981 and 1983, and short cores were collected from S. fuscum hummocks at 20 bogs along the transect. Shoot elongation ranged from 3 mm year −1 in Newfoundland to 11.2 mm year −1 in western Québec, with values of 7 mm year −1 for sites in the southern maritimes. Productivity ranged from 103 to 307 g m −2 year −1 . Shoot elongation was negatively correlated with bulk density ( r 2 = 0.93, p &lt; 0.0002). Bulk density decreased from maritime to mid-continental sites consistent with existing classifications of maritime, transitional, and continental sites based on landforms, vegetation, and stratigraphy. Productivity was positively correlated with GDD5 and negatively correlated with precipitation and vascular plant cover. These data fill an important gap in measurement of Sphagnum growth and patterns of productivity in this region.