Data from: Drivers of intra-individual spatial variability in methane emissions from tree trunks in upland forest

<p><span>CH</span>_{<span>4</span>}<span> emissions from </span><span>tree </span><span>trunks in upland forests should be scaled accurately</span><span> in order</span><span> to assess the role of tree trunk</span><span>s</span><span> in </span><span>the </span><span>forest CH₄</span><span> budget. As </span><span>the </span><span>chambers used to measure emission</span><span>s</span><span> cover</span><span> only</span><span> a small part of the tree trunks, </span><span>it is necessary to </span><span>understand the intra-individual spatial variability </span><span>in</span><span> trunk CH₄</span><span> emission</span><span>s.</span> <span>W</span><span>e measured trunk CH₄</span><span> flux at nine locations per individual </span><span>on</span><span> four trees in a cool-temperate upland forest. To </span><span>appreciate</span> <span>the origin of th</span><span>is</span><span> variability and </span><span>the underlying</span><span> processes, we also measured</span><span> the</span><span> potential</span><span> rate of </span><span>CH</span><span>4</span><span> production and CH</span>_{<span>4</span>}<span> concentration </span><span>at</span><span> sapwood and </span><span>characterized </span><span>wood and bark. Up to 15-fold spatial </span><span>variation in CH₄</span><span> fluxes were observed</span><span> at</span><span> the</span><span> individual</span><span> level</span><span>. This variability </span><span>can be highlighted </span><span>by the variation </span><span>in </span><span>the sapwood CH₄</span><span> concentration which </span><span>was</span><span> further </span><span>explained</span> <span>by </span><span>the variation in CH₄</span><span> production rate. The radial CH₄</span><span> diffusivity calculated from concentration gradient</span><span>s</span><span> and emission</span><span>s</span><span> was not related to the </span><span>measured </span><span>characteristics of </span><span>either </span><span>wood </span><span>or</span><span> bark, </span><span>raising the question of</span><span> the diffusion pathway. We emphasize</span><span>d</span><span> the importance </span><span>of</span><span> sampl</span><span>ing</span><span> trunk CH₄</span><span> flux at multiple locations on the surface of a tree trunk</span> <span>to capture spatial variability, a prerequisite for estimating tree-level CH₄</span><span> emissions.</span></p>