Collaborative Research: Lightning-caused disturbance and patterns of recovery in tropical forests

热带森林之所以受到关注，是因为它们拥有异常高水平的生物多样性，是全球碳收支的主要贡献者。热带树木死亡模式的持续变化正在危及这种生物多样性，并降低森林积累碳的能力。这反过来将对全球气候变化产生影响。该研究小组最近的研究表明，闪电可能是破坏热带森林的主要因素之一。这一新阶段的研究将问：闪电在森林中的影响有多一致，以及它们如何从雷击破坏的影响中恢复过来？该项目将通过生态学、大气物理学和生态系统科学的进步，量化热带森林中闪电的短期和长期影响。这项研究的结果将考察闪电对热带森林的重要性，更广泛地说，它对碳循环的影响，以及对全球气候趋势的影响。这项研究的更广泛影响将培养博士后研究人员，并为本科生和研究生提供国际研究经验。该项目还将在史密森国家自然历史博物馆以及巴拿马的机场和中央巴士终点站制作展品，让公众参与科学进程。在网上，将开发闪电虚拟旅游，虚拟资源将为未被充分代表的学生提供专业发展培训，以继续研究生教育。热带雨林是世界上研究生物多样性和生态系统过程的最佳课堂，该项目为学生提供了绝佳的机会，通过展览和在线活动获得宝贵的教育经验。这项研究的主要目的是量化雷击对热带森林周转和演替动态的贡献。中心假设是，雷击通过对树木死亡的直接贡献和对干扰后森林恢复的间接影响而减少森林碳储量。我们将结合森林生态学、闪电物理和遥感的专业知识来解决三个核心问题：(1)闪电是否引发了相对于风抛出的森林更新的替代途径？(2)闪电干扰特征如何随林龄和树种组成而变化？(3)闪电如何调节森林结构和碳动态的区域差异？这个项目建立在这组研究人员最近的研究结果基础上，表明闪电对热带森林周转的影响被严重低估。这些发现是通过研究一片低地森林得出的。要广泛了解闪电在热带森林中的作用，需要将这种方法应用于一系列森林类型。将开发一种先进的闪电定位系统，系统地量化约8000平方公里热带森林每年约40,000次闪电的影响，包括组成、大小结构和年龄的变化。将使用时间序列方法来确定在干扰后更新期间，闪电如何影响树木群落组装和生物量积累。量化这些跨尺度影响将有助于管理热带雨林和我们这个星球的未来。这项工作的成果预计将大大提高对热带森林生态系统的科学理解。这一奖项反映了NSF的法定使命，并通过使用基金会的智力优势和更广泛的影响审查标准进行评估，被认为值得支持。

Tropical forests garner attention because they are home to exceptionally high levels of biodiveristy, and are dominant contributors to the global carbon budget. Ongoing changes in patterns of tree death in the tropics are endangering this biodiversity, and decreasing the ability of forests to accumulate carbon. This, in turn, will have an impact on global climate change. Recent work by this team has revealed that lightning could be one of the major factors disrupting tropical forests. This new phase of research will ask: how consistent are the effects of lightning strikes among forests, and how do they recover from the effects of damage by lightning? This project will quantify the short- and long-term effects of lightning among tropical forests through advances in ecology, atmospheric physics, and ecosystem science. Results of this study will examine the importance of lightning to tropical forests and, more broadly, its effects on carbon cycling, and the impact that has on global climate trends. The broader impacts of this research will train a postdoctoral researcher and offer international research experiences to undergraduate and graduate students. The project will also produce exhibits at the Smithsonian's National Museum of Natural History, and at the airport and central bus terminal in Panama, to engage the public in the scientific process. Online, virtual tours of lightning strikes will be developed, and virtual resources will make professional development training available for underrepresented students to pursue graduate education. Tropical rainforests are the world's best classroom for studying biodiversity and ecosystem processes, and this project provides outstanding opportunities for students to gain valuable educational experiences in-person, via exhibits, and through online activities. The principal goal of this study is to quantify the contributions of lightning strikes to tropical forest turnover and successional dynamics. The central hypothesis is that lightning strikes reduce forest carbon storage via their direct contributions to tree mortality and indirect effects on post-disturbance forest recovery. We will combine expertise in forest ecology, lightning physics, and remote sensing to address three core questions: (1) Does lightning trigger an alternative pathway of forest regeneration relative to windthrow?; (2) How do lightning disturbance characteristics vary with forest age and tree species composition?; and (3) How do lightning strikes regulate regional differences in forest structure and carbon dynamics? This project builds on recent results by this team of researchers, showing that the effects of lightning on tropical forest turnover have been grossly underestimated. Those findings were made by studying a single lowland forest. Broadly understanding the role of lightning in tropical forests requires applying this approach to a range of forest types. An advanced lightning location system will be developed to systematically quantify the effects of ca. 40,000 annual lightning strikes across ca. 8,000 km2 of tropical forest that encompass variation in composition, size structure, and age. A chronosequence approach will be used to determine how lightning influences tree community assembly and biomass accumulation during post-disturbance regeneration. Quantifying these cross-scale effects will help in the management tropical forests and the future of our planet. The outcomes of this work are expected to substantially improve scientific understanding of tropical forest ecosystems.This award reflects NSF's statutory mission and has been deemed worthy of support through evaluation using the Foundation's intellectual merit and broader impacts review criteria.