Application of multidimensional structural characterization to detect and describe moderate forest disturbance
Application of multidimensional structural characterization to detect and describe moderate forest disturbance
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DOI：
10.1002/ecs2.3156
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发表时间：
2020-06-01
期刊：
影响因子：
2.7
通讯作者：
Gough, Christopher M.
中科院分区：
文献类型：
--
作者：
Atkins, Jeff W.;Bond-Lamberty, Ben;Gough, Christopher M.
一个多世纪以来，对植被群落和结构变化的研究一直是生态学的核心，然而，干扰重塑森林冠层物理结构的方式仍然相对未知。中度扰动影响不同的冠层和植物种类，导致不同的结构结果和生态后果。陆地激光雷达（光探测和测距）提供了冠层元素内部排列和分布的前所未有的视图，允许导出冠层结构的多维测量，这些测量描述了与生态系统功能已知联系的几种冠层结构特征（CSTs）。我们在机器学习框架内使用激光雷达衍生的CSTs来检测和描述由各种干扰因素引起的结构变化，包括中度火灾、冰暴损害、年龄相关衰老、铁杉毛状硬体、山毛榉树皮病和慢性酸化。我们发现，火灾和冰暴主要影响冠层内植被的数量和位置，而酸化、衰老、病原体和昆虫侵染则改变冠层的排列和复杂性。六种干扰剂中只有两种显著减少叶面积，与许多中度严重干扰的常见假设相反。虽然由于缺乏干扰之间的复制，研究结果的普遍性受到限制，但它们确实表明，目前标准干扰检测方法（如基于光学的遥感平台，通常是冠层上方的视角）的局限性限制了我们理解干扰的完整生态和结构影响的能力，以及评估干扰因子内部和之间结构模式一致性的能力。一个更广泛的生态干扰定义包含了冠层结构变化的多个方面，可能会潜在地改善中度严重干扰的建模、检测和功能影响的预测，并拓宽我们对干扰的生态影响的理解。
The study of vegetation community and structural change has been central to ecology for over a century, yet the ways in which disturbances reshape the physical structure of forest canopies remain relatively unknown. Moderate severity disturbances affect different canopy strata and plant species, resulting in variable structural outcomes and ecological consequences. Terrestrial lidar (light detection and ranging) offers an unprecedented view of the interior arrangement and distribution of canopy elements, permitting the derivation of multidimensional measures of canopy structure that describe several canopy structural traits (CSTs) with known links to ecosystem function. We used lidar-derived CSTs within a machine learning framework to detect and describe the structural changes that result from various disturbance agents, including moderate severity fire, ice storm damage, age-related senescence, hemlock woolly adelgid, beech bark disease, and chronic acidification. We found that fire and ice storms primarily affected the amount and position of vegetation within canopies, while acidification, senescence, pathogen, and insect infestation altered canopy arrangement and complexity. Only two of the six disturbance agents significantly reduced leaf area, counter to common assumptions regarding many moderate severity disturbances. While findings are limited in their generalizability due to lack of replication among disturbances, they do suggest that the current limitations of standard disturbance detection methods-such as optical-based remote sensing platforms, which are often above-canopy perspectives-limit our ability to understand the full ecological and structural impacts of disturbance, and to evaluate the consistency of structural patterns within and among disturbance agents. A more broadly inclusive definition of ecological disturbance that incorporates multiple aspects of canopy structural change may potentially improve the modeling, detection, and prediction of functional implications of moderate severity disturbance as well as broaden our understanding of the ecological impacts of disturbance.