ABSTRACT

A lidar-derived canopy height profile (CHP), generated from canopy bulk density (CBD) estimates for a sequence of 1-m increments through the canopy, provides a physical measure of forest structure. Measurement of physical properties are intuitively understandable and thus facilitate the use of lidar for investigating hypotheses regarding avian resource use. We illustrate the use of lidar-derived physical measures to explore the hypothesis that golden eagles (Aquila chrysaetos) prefer an open understory, which potentially aids visual identification of prey. Two golden eagles fitted with GPS tracking devices overwintered in the New Jersey Pinelands National Preserve. We generated CHPs from discrete-return lidar data for an area occupied by the birds. We compared the CHPs of sites the birds occupied to the surrounding available habitat and found that the occupied sites were significantly lower in CBD from the ground up to 5 m for perched/stationary birds, and from the ground up to 8 m for birds in flight. These results could be used by forest resource managers for promoting golden eagle habitat through prescribed fire. In addition, these results demonstrate the power of lidar to generate physically and intuitively meaningful measures of forest structure.

摘要

激光雷达衍生的树冠高度剖面 (CHP) 由树冠体积密度 (CBD) 估计生成，通过树冠对 1 米增量序列进行估计，提供森林结构的物理测量。物理特性的测量可以直观地理解，因此有助于使用激光雷达来研究有关鸟类资源使用的假设。我们说明了使用激光雷达衍生的物理测量来探索金鹰 ( Aquila chrysaetos ) 的假设) 更喜欢开放的林下，这可能有助于视觉识别猎物。两只装有 GPS 跟踪设备的金鹰在新泽西松林国家保护区越冬。我们根据鸟类所占据区域的离散返回激光雷达数据生成 CHP。我们将鸟类占据的地点与周围可用栖息地的 CHP 进行了比较，发现在 CBD 的占据地点明显较低，对于栖息/静止的鸟类，从地面到 5 m，对于飞行中的鸟类，从地面到 8 m . 这些结果可以被森林资源管理者用来通过规定的火来促进金鹰栖息地。此外，这些结果证明了激光雷达能够生成物理上和直观上有意义的森林结构测量值。