Collaborative Research: Lightning as an agent of tropical tree mortality

闪电是一种异常强大的自然现象；纵观历史，它的破坏性影响一直是人类恐惧和迷恋的根源。科学家们对闪电的物理特性有了相对较好的理解，但它在景观尺度上的生态重要性——尤其是它作为树木死亡媒介的作用——仍不清楚。测量热带森林中闪电的影响很重要，因为随着气候变暖，预计未来几十年闪电频率将增加50%。这项研究将为理解这些变化如何影响森林动态和生态系统过程（如碳循环）提供基础。具体来说，它将决定树木的大小、位置和物种特征如何影响它被雷击死的概率；它将测量森林中因雷击而死的木头的数量。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亨茨维尔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。巴拿马的场地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冠层的研究引起了国际媒体的关注，该项目有望引起类似的公众兴趣。最后，该项目还包括与肯塔基科学中心教育主任的合作，他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环境中与项目参与者组织公众讨论。本研究的主要目的是量化雷电对热带低地森林树木和藤本植物的生态影响。该研究采用了最新的高科技闪电传感器与数字摄像机相结合，实时记录并精确定位大约20平方公里森林冠层上的云对地闪电。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昆虫分布中起重要作用。这项工作将整合野外生态学、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，闪电产生的枯木形式的碳含量是多少？3)雷害的分布是否影响林冠昆虫的分布？这项工作将通过测量闪电对整个景观中不同森林成分的影响，提高对热带森林动态的认识。具体来说，它将揭示闪电、藤本植物、树木和昆虫之间的关键相互作用。总体而言，该项目将首次提供热带森林中闪电分布、频率和生物效应的精确测量。

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.