Changes in carbon density for three old-growth forests on Changbai Mountain, Northeast China: 1981–2010

IntroductionThe old-growth forests on Changbai Mountain have been well protected from human activities and provide a living laboratory for studying forest carbon sequestration under natural environmental conditions.ObjectivesWe used data from permanent plots measured periodically in 1981 and 2010 to quantify carbon densities for Korean pine-broadleaf mixed forest, coniferous forest and Erman’s birch forest on Changbai Mountain.ResultsCarbon pools were divided into tree stems, leaves, branches, coarse woody debris, tree roots, and soil. Although the mixed forest experienced minor wind damage, every forest component except for coarse woody debris experienced increases in carbon density, and the total forest carbon density increased from 233 to 317 t C ha−1. The coniferous forest was severely damaged by wind, so carbon content in trees decreased but the total forest carbon density still increased from 298 to 327 t C ha−1. The birch forest gained much carbon in trees but the soil carbon pool remained relatively stable, and its total carbon density increased from 226 to 281 t C ha−1. The old-growth forest was more resilient to disturbance than previously thought. The positive increases in carbon for the three old-growth forests suggest that forest landscapes on Changbai Mountain are indeed carbon sinks.