Spatial variations in the microfibril angle (MFA) of cellulose are mapped on individual radial sections of wood from the maturing stems of Australian tree species (Acacia floribunda, Acacia suaveolens, Acacia doratoxylon, Acacia havilandiorum, Brachychiton populneus and Bertya cunninghamii) from different rainfall and soil nutrient availabilities using synchrotron wide angle X-ray scattering. For the three species with the smallest radial variation there is a clear linear relationship between the MFA with Young’s modulus and wood density with data published previously for these samples. The other three samples show a large radially symmetric variation in MFA across the radial section either having a continuous change from large MFA in the stem’s centre to small value close to the bark or the reverse, small MFA at the centre to larger values close to the bark. For these samples, a strong linear correlation between the Young’s modulus and density and the MFA is not apparent. We conclude that spatially localised measurements of MFA provide an important insight in the adaptation of wood tissue to environmental conditions.

中文翻译：

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同步辐射研究成熟树干木本组织中微纤维角的空间调制

纤维素微原纤维角 (MFA) 的空间变化被绘制在来自不同降雨和不同降雨量的澳大利亚树种（Acacia floribunda、Acacia suaveolens、Acacia doratoxylon、Acacia havilandiorum、Brachychiton populneus 和 Bertya cunninghamii）的成熟茎干木材的各个径向截面上使用同步加速器广角 X 射线散射测定土壤养分有效性。对于具有最小径向变化的三个物种，MFA 与杨氏模量和木材密度之间存在明显的线性关系，这些数据之前已发布这些样品的数据。其他三个样品在径向截面上显示出较大的 MFA 径向对称变化，或者具有从茎中心的大 MFA 到靠近树皮的小值的连续变化，或者相反，中心的小 MFA 到靠近树皮的较大值。对于这些样品，杨氏模量和密度与 MFA 之间的强线性相关性并不明显。我们得出结论，MFA 的空间局部测量为木材组织对环境条件的适应提供了重要的见解。