Fractal characteristics of macroscopic and microscopic cell-piled structure patterns of wood

In the paper, we aim to provide a quantitative description of apparent characteristics of the macroscopic and microscopic cell-piled structure patterns of wood and acquire further information relating to wood structure, which cannot be described quantitatively. Based on the fractal analysis of differential box-counting dimension on macroscopic tangential section and microscopic tri-sectional structure photos of 18 species of wood in northeast China, results show that: 1) macroscopic structural texture and microscopic structural patterns of the cell-piled wood both have fractal features, and they have very good characteristics of macroscopic and microscopic structural texture and patterns of roughness and order; 2) compared with softwood, the macroscopic tangential section and microscopic tri-sectional patterns of hardwood have higher fractal dimensions, which shows that macroscopic and microscopic cell-piled structure patterns of hardwood are more rough and its order is more complicated; 3) the general rule for the microscopic tri-sectional structure pattern of fractal dimension of softwood and hardwood trees is: transverse section tangential section radial section; 4) when some types of cells are substituted, the existence of resin, vessels and wood parenchyma can influence the fractal dimension changes of the microscopic structural patterns of wood to various degrees.