Tree improvement programs are critical to establishing high yield seed sources while maintaining genetic diversity and developing sustainable plantation forests. Douglas-fir (Pseudotsuga menziesii (Mirb.) Franco) is commonly used in improvement programs due to its superior strength and stiffness properties. Progeny testing trials in British Columbia (BC), Canada aim to increase stem volume without sacrificing wood quality. As genetically improved stock in BC is entering its fourth generation, wood quality and branch attributes are becoming more important as selection criteria evolve. This study investigates the utility of Airborne Laser Scanning (ALS) to produce metrics that describe branch attributes, and test whether these attributes showed differences in trees of three different genetic gain levels (GL); Wild-Stand (WS), Mid-Gain (MG) and Top-Cross (TC), planted at two different spacings (2.9 m and 4.0 m) in a realized-gain trial. New methods were developed to utilize ALS data to estimate metrics such as branch angle, length and volume using a point clustering approach. The relative impact of GL and spacing on branch attributes were assessed. Spacing was significant for branch angle (2.9 m = 73.53°, 4.0 m = 72.46°), whereas GL (WS = 0.861 m, MG = 0.917 m, TC = 0.948 m) and spacing (2.9 m = 0.884, 4.0 m = 0.942) were significant for length. For all metrics, TC trees at 4.0 m spacing were consistently significantly different whenever GL or the interaction effect was significant. This data provide an insight into how ALS can be used to model branch attributes, whereas the ability to analyse trees by plot, individual tree and individual branch attributes further allows researchers and foresters to maximize the value of ALS data. Findings from this research can be integrated into large-scale programs not just for monitoring trees, but also for identifying new trees that can display attributes associated with larger volumes and increased value.

中文翻译：

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通过机载激光扫描获得的道格拉斯冷杉的内部冠部几何特征

树木改良计划对于建立高产种子源，维持遗传多样性和发展可持续人工林至关重要。道格拉斯冷杉（Pseudotsuga menziesii（Mirb。）Franco）由于其卓越的强度和刚度特性而常用于改进程序。在加拿大不列颠哥伦比亚省（BC）进行的后代测试试验旨在在不牺牲木材质量的前提下增加茎的体积。随着卑诗省基因改良种群进入第四代，随着选择标准的发展，木材质量和分支属性变得越来越重要。这项研究调查了机载激光扫描（ALS）产生描述分支属性的指标的效用，并测试了这些属性是否在三种不同遗传增益水平（GL）的树中显示出差异。在实际获利的试验中，以两个不同的间距（2.9 m和4.0 m）种植了Wild-Stand（WS），Mid-Gain（MG）和Top-Cross（TC）。开发了利用ALS数据估算指标（例如分支角度，使用点聚类方法的长度和体积。评估了GL和间距对分支属性的相对影响。分支角（2.9 m = 73.53°，4.0 m = 72.46°）的间距显着，而GL（WS = 0.861 m，MG = 0.917 m，TC = 0.948 m）和间距（2.9 m = 0.884，4.0 m = 0.942） ）的长度很重要。对于所有指标，只要GL或交互作用显着，则4.0 m间距处的TC树始终存在显着差异。该数据提供了有关如何使用ALS建模分支属性的见解，而通过地块，单个树和单个分支属性分析树木的能力进一步使研究人员和林业工作者可以最大化ALS数据的价值。这项研究的结果可以集成到大型程序中，而不仅仅是监视树木，