Collaborative Research: Lightning as an agent of tropical tree mortality

闪电是一种特别强大的自然现象；在整个历史上，它的破坏性影响一直是人类恐惧和迷恋的来源。科学家们对闪电的物理学有了相对较好的了解，但它在景观尺度上的生态重要性--特别是它作为树木死亡媒介的作用--仍然不清楚。测量热带森林中闪电的影响很重要，因为随着气候变暖，未来几十年闪电频率预计将增加50%。这项研究将为理解这种变化将如何影响森林动态和生态系统进程(如碳循环)提供基础。具体地说，它将确定一棵树的大小、位置和物种身份如何影响它被雷击致死的可能性；它还将测量森林中因雷击而存在的枯木量。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，该项目为路易斯维尔大学和位于亨茨维尔的阿拉巴马大学的学生提供了在国际环境中获得宝贵的第一手研究经验的绝佳机会。巴拿马的实地景点是一个受欢迎的旅游目的地，因此该项目为参与者提供了一个与公众定期互动的独特机会。研究人员先前对雨林树冠的研究引起了国际媒体的关注，该项目预计也会引起类似的公众兴趣。最后，该项目包括与肯塔基州科学中心教育主任的合作，后者将制作突出这项研究的博物馆展览，并将在非正式的科学咖啡馆中组织与项目参与者的公开讨论。这项研究的主要目的是量化闪电对低地热带森林树木和藤本植物(木本藤本植物)的生态影响。这项研究利用最新的高科技闪电传感器与数字摄像机相结合，实时记录和精确定位约20平方公里森林树冠上的云对地闪电。中心假设是闪电是热带树木和藤本植物死亡的主要原因，因此在碳循环和植食性昆虫分布中发挥重要作用。这项工作将综合田间生态学、遥感、大气科学和物理学的信息，回答三个基本问题：1)什么因素影响热带树木遭受雷击的概率？2)在整个森林范围内，雷击产生的死木形式的碳的数量是多少？3)雷击危害的分布是否影响树冠昆虫的分布？这项工作将通过测量闪电对整个景观中不同森林组成部分的影响来提高对热带森林动态的了解。具体地说，它将揭示闪电、藤本植物、树木和昆虫之间的关键相互作用。作为一个整体，该项目将提供第一个准确测量热带森林中闪电分布、频率和生物效应的方法。

Lightning is an exceptionally powerful natural phenomenon; its destructive effects have been a source of fear and fascination for humans throughout history. Scientists have a relatively good understanding of the physics of lightning, but its ecological importance at the landscape scale--especially its role as an agent of tree death--remain unclear. Measuring the effects of lightning in tropical forests is important because lightning frequency is expected to increase by as much as 50% over the next few decades as the climate warms. This research will provide the foundation for understanding how such changes will affect forest dynamics and ecosystem processes such as carbon cycling. Specifically, it will determine how the size, location, and species identity of a tree affects the probability that it will be killed by lightning; and it will measure the amount of dead wood present in a forest due to lightning strikes. Tropical rainforests are the world's best classroom for studying biodiversity and ecosystem processes, and this project provides outstanding opportunities for students at the University of Louisville and the University of Alabama in Huntsville to gain valuable first-hand research experience in an international setting. The field site in Panama is a popular tourist destination, thus the project provides a unique opportunity for participants to interact regularly with the public. Prior studies by the researchers on rainforest canopies attracted international media attention, and this project is expected to generate similar public interest. Finally, this project includes a collaboration with the Director of Education at the Kentucky Science Center, who will produce museum displays highlighting this research, and will organize public discussions with project participants in an informal Science Café setting. The principal objective of this study is to quantify the ecological effects of lightning on trees and lianas (woody vines) in a lowland tropical forest. The research employs the latest high-tech lightning sensors in combination with digital video cameras to record and precisely locate cloud-to-ground lightning flashes over approximately 20 square km of forest canopy in real time. The central hypothesis is that lightning is a major agent of tropical tree and liana mortality, and thereby plays an important role in carbon cycling and plant-feeding insect distributions. The work will integrate information from field ecology, remote sensing, atmospheric science, and physics to answer three basic questions: 1) What factors affect the probability of lightning strikes to tropical trees?; 2) What is the amount of carbon in the form of dead wood produced by lightning on a forest-wide scale?; and 3) Does the distribution of lightning damage affect canopy insect distributions? This work will improve knowledge of tropical forest dynamics by measuring the effects on lightning on different forest components across the landscape. Specifically, it will uncover key interactions among lightning, lianas, trees, and insects. As a whole, the project will provide the first accurate measure of lightning distribution, frequency, and biological effects in a tropical forest.