摘 要
桉树人工林作为全球重要的速生工业用材林，在木材生产中占据关键地位，但其密度调控对木材品质的影响尚需深入研究。本研究以5年生巨桉人工林为对象，通过设置不同种植密度梯度（800、1200、1600株/公顷），分析密度变化对木材解剖结构、物理性能及化学成分的影响。结果表明，随着种植密度的增加，树木胸径显著减小，而树高增长加快；木材基本密度呈现先升高后降低的趋势，最优密度区间为1200株/公顷。此外，低密度条件下木材纤维长度显著增加，但纤维壁厚比例下降，导致力学强度略有减弱。化学分析显示，高密度处理下木材纤维素含量较高，而木质素比例相对较低，这有利于纸浆生产但可能影响建筑用材性能。本研究创新性地结合了解剖学与理化指标综合评价方法，揭示了密度调控对木材多维度品质的交互作用机制，为优化桉树人工林经营策略提供了科学依据。关键词：桉树人工林; 密度调控; 木材品质; 解剖结构; 化学成分
Abstract
Eucalyptus plantations, as a globally significant fast-growing industrial timber resource, play a crucial role in wood production; however, the impact of density regulation on wood quality requires further investigation. This study focused on 5-year-old Eucalyptus grandis plantations, establishing different planting density gradients (800, 1200, and 1600 trees per hectare) to analyze the effects of density variations on wood anatomical structure, physical properties, and chemical composition. The results demonstrated that with increasing planting density, tree diameter at breast height significantly decreased, while tree height growth accelerated. The basic wood density exhibited an initial increase followed by a decrease, with the optimal density range identified as 1200 trees per hectare. Additionally, under low-density conditions, fiber length significantly increased, but the fiber wall thickness ratio decreased, leading to a slight reduction in mechanical strength. Chemical analysis revealed higher cellulose content and relatively lower lignin proportions under high-density treatments, which is advantageous for pulp production but may compromise the performance of construction materials. Innovatively integrating anatomical and physicochemical evaluation methods, this study elucidated the interactive mechanisms of density regulation on multi-dimensional wood quality, providing a scientific basis for optimizing management strategies in Eucalyptus plantations.Key words:Eucalyptus Plantation; Density Regulation; Wood Quality; Anatomical Structure; Chemical Composition
目 录
中文摘要 I
英文摘要 II
引 言 1
第1章、桉树人工林密度调控基础 2
1.1、密度调控的生态学意义 2
1.2、人工林密度管理现状 2
1.3、密度与木材品质的关系 3
第2章、密度对木材物理特性的影响 4
2.1、木材密度的变化规律 4
2.2、纤维长度与直径分析 4
2.3、物理特性的优化路径 4
第3章、密度对木材化学成分的作用 6
3.1、木质素含量的动态变化 6
3.2、纤维素比例的影响因素 6
3.3、化学成分与加工性能 7
第4章、密度调控的实践与策略 8
4.1、不同密度下的生长模型 8
4.2、木材品质提升的技术手段 8
4.3、综合调控的经济与环境效益 8
结 论 10
参考文献 11
