Differences in submillimetre surface morphology and canopy interception storage capacities of Gleditsia triacanthos L. (honeylocust) in relation to canopy phenophase and position

The purpose of this study is to examine submillimetre surface morphology and interception storage capacity of foliar surfaces for Gleditsia triacanthos L. (honeylocust) in relation to canopy phenophase (emergence, full leaf, and senescence) and bark surfaces with respect to canopy position through the integration of bioimaging microscopy techniques, three‐dimensional (3D) surface mapping, and laboratory‐based storage capacity analyses. The results demonstrate that there were some statistically significant differences in foliar microrelief and storage capacity across canopy phenophases. Mean foliar roughness and storage capacity peaked during the full leaf phenophase at 173 μm and 0.019 ml cm−2, respectively. Both foliar microrelief and storage capacity were least during emergence. The decreased surface roughness during senescence as compared with full leaf might be due to the tree's inability to repair environmentally induced degradation of the morphological microstructures and epicuticular wax during that phase. Bark microrelief and storage capacity both varied as a function of tree height, with the greatest mean roughness (859 μm) and storage capacity (0.094 ml cm−2) observed in the lower tree. The observed reduction in bark microrelief and storage capacity with height may be attributable to bark age and thickness. Further research that links the 3D submillimetre morphology of canopy surfaces by identifying specific physical mechanisms and processes that either promote or inhibit water storage on foliar and bark surfaces is needed.