Tree rings from a European beech forest chronosequence are useful for detecting growth trends and carbon sequestration

Past carbon (C) storage trends were estimated using dendroecological methods in a beech chronosequence in central Germany. Raw-ring-width chronologies, sensitivity curves, and carbon uptake trends were developed for 70-, 110-, and 150-year-old (S70, S110, and S150), even-aged stands. Ecosystem C stock and net ecosystem productivity (NEPC) were computed as the sum of the C stock and fluxes of the soil, the aboveground compartment, and the estimated belowground compartment. The ecosystem C stock ranged from 216 t C·ha–1 in S150, to 265 t C·ha–1 in S70, to 272 in S110. NEPC values followed ecosystem C stocks, ranging from 1.7, to 2.4, to 5.1 t C·ha–1·year–1 for S150, S70, and S110, respectively. Stem Cstock uptake rate in S110 showed an increase in growth rate over the first 110 years of S150. We estimate that this increase in stem C stock was 6.2%. Given the constancy of forest management among the stands of the chronosequence, we hypothesize that the increase in C stock shown by S110 is due to indirect humaninduced effects. We conclude that managed young forests can take advantage of increased resources and counteract the C losses at harvest that are seen in the old forests.