The application of wood decay fungi to enhance annual ring detection in three diffuse-porous hardwoods

At the macroscopic level, the detection of tree rings of diffuse porous wood is still a major issue. As an alternative method to conventional preparation techniques, wood decay fungi were employed as analytic tools for tree ring analysis in diffuse porous wood. Wood blocks of sycamore (Acer pseudoplatanus L.), silver birch (Betula pendula Roth.) and aspen (Populus tremula L.) were incubated for 4, 8 and 12 weeks with two brown rot fungi, Fomitopsis pinicola and Laetiporus sulphureus, respectively. In addition, exposure of tree rings in wood degraded under controlled conditions was compared with several sanding and staining techniques and/or combinations of the latter. The ability to discern tree rings in the treated wood varied depending on the wood spp., method applied and duration of degradation. Exposure of annual ring borders in degraded sycamore and birch wood samples was apparently superior to conventional methods. In contrast, annual ring detection in aspen wood was greatly enhanced when both methods were applied. Further studies are required to improve the potential use of wood decay fungi as analytical tools in tree ring analysis.