Canopy damage and recovery following Hurricane Maria using multitemporal lidar data, Mar-2017 - Mar-2020, Puerto Rico

The data archive is here: http://dx.doi.org/10.15486/ngt/1797399 please use this DOI when citing this dataset. Hurricane Maria (Category 4) snapped and uprooted canopy trees, removed large branches, and defoliated vegetation across Puerto Rico. The magnitude of forest damages and the rates and mechanisms of forest recovery following Maria provide important benchmarks for understanding the ecology of extreme events. We used airborne lidar data acquired before (2017) and after Maria (2018, 2020) to quantify landscape-scale changes in forest structure along a 439-ha elevational gradient (100 to 800 m) in the Luquillo Experimental Forest. Damages from Maria were widespread, with 73% of the study area losing ≥1 m in canopy height (mean = -7.1 m). Taller forests at lower elevations suffered more damage than shorter forests above 600 m. Yet only 13% of the study area had canopy heights ≤2 m in 2018, a typical threshold for forest gaps, highlighting the importance of damaged trees and advanced regeneration on post-storm forest structure. Heterogeneous patterns of regrowth and recruitment yielded shorter and more open forests by 2020. Nearly 45% of forests experienced initial height loss (<-1 m, 2017-2018) followed by rapid height gain (>1 m, 2018-2020), whereas 21.6% of forests with initial height losses showed little or no height gain, and 17.8% of forests exhibited no structural changes >|1| m in either period. Canopy layers <10 m accounted for most increases in canopy height and fractional cover between 2018-2020, with gains split evenly between height growth and lateral crown expansion by surviving individuals. These findings benchmark rates of gap formation, crown expansion, and canopy closure following hurricane damage. Included in the attached zip file are four TIF and four KML files. Support for this work was provided by grants BSR-8811902, DEB-9411973, DEB-9705814 , DEB-0080538, DEB-0218039 , DEB-0620910 , DEB-1239764, DEB-1546686, and DEB-1831952 from the National Science Foundation to the University of Puerto Rico as part of the Luquillo Long-Term Ecological Research Program. Additional support provided by the University of Puerto Rico and the International Institute of Tropical Forestry, USDA Forest Service.

本数据集存档链接为：http://dx.doi.org/10.15486/ngt/1797399，引用本数据集时请使用该DOI编号。四级飓风玛丽亚（Hurricane Maria）折断并拔起冠层树木、移除大量枝条并使植被落叶，波及波多黎各全境。玛丽亚引发的森林破坏规模，以及灾后森林恢复的速率与机制，为理解极端事件的生态学效应提供了重要基准。本研究借助2017年（飓风过境前）与玛丽亚灾后2018年、2020年获取的机载激光雷达（lidar）数据，对卢奎略实验森林（Luquillo Experimental Forest）内一处面积439公顷、海拔梯度为100至800米的区域，量化了森林结构的景观尺度变化。玛丽亚造成的破坏范围广泛，研究区域内73%的区域冠层高度下降≥1米（平均下降7.1米）。低海拔区域的高大林分较600米以上的矮小林分受损更为严重。但2018年仅有13%的研究区域冠层高度≤2米——这是森林林隙的典型阈值——这凸显了受损树木与先进更新对灾后森林结构的重要性。异质性的再生与补充模式使得2020年的森林冠层更矮且更为开阔。近45%的森林经历了初始高度损失（2017-2018年，损失<-1米）后出现快速高度回升（2018-2020年，回升>1米）；而21.6%的存在初始高度损失的森林几乎未出现高度回升；另有17.8%的森林在两个时段内均未出现|1|米以上的结构变化。2018-2020年间，冠层高度与盖度的增长主要来自<10米的冠层层级，增长由存活个体的高度生长与侧向冠幅扩张平均分摊。本研究结果为飓风破坏后的林隙形成、冠幅扩张与冠层闭合速率提供了基准参照。附件压缩包中包含4个TIF文件与4个KML文件。本研究得到美国国家科学基金会（National Science Foundation）授予波多黎各大学（University of Puerto Rico）的多项拨款支持（BSR-8811902、DEB-9411973、DEB-9705814、DEB-0080538、DEB-0218039、DEB-0620910、DEB-1239764、DEB-1546686、DEB-1831952），作为卢奎略长期生态研究项目（Luquillo Long-Term Ecological Research Program）的组成部分。此外还得到波多黎各大学与美国农业部林务局国际热带森林研究所（International Institute of Tropical Forestry, USDA Forest Service）的资助。