Carbon flux from decomposing wood and its dependency on temperature, wood N2 fixation rate, moisture and fungal composition in a Norway spruce forest

• DOI: 10.1111/gcb.14594
• Publication Date: 2019-02-15T09:26:47Z
• Authors: Katja T. Rinne‐Ga...; Krista Peltoniemi; Janet Chen; Mikko Peltoniemi; Hannu Fritze; Raisa Mäkipää
• Keywords: Coarse Woody Debris

Abstract Globally 40–70 Pg of carbon (C) are stored in coarse woody debris on the forest floor. Climate change may reduce function this stock as a C sink future due to increasing temperature. However, current knowledge drivers wood decomposition is inadequate for detailed predictions. To define factors that control respiration rate Norway spruce and produce model adequately describes process species time, we used an unprecedentedly diverse analytical approach, which included measurements respiration, fungal community sequencing, N 2 fixation rate, nifH copy number, 14 C‐dating well N%, δ 13 C% values wood. Our results suggest climate will accelerate flux from deadwood boreal conditions, observed strong temperature dependency respiration. At research site, annual would increase by 27% 117 g C/kg with projected warming (RCP4.5). The second most important was stage decomposition; at early stages low nitrogen content moisture limited activity while reduced resource quality decreased final decomposition. Wood best described Sigmoidal model, where after 116 years mass loss 95% reached. budget calculations ecosystem models. We first time fixation, has major role providing wood‐inhabiting fungi, not constant but varied between density classes source supply quality. This significant consequences projecting rates changing climate.