Collaborative Research: The biology of lightning in tropical forests

University Of Alabama In Huntsville, Huntsville AL

Investigators

Abstract

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. Moreover, tropical forest structure is changing as lianas (woody vines) become more abundant. This research will provide the foundation for understanding how such changes will affect forest dynamics and ecosystem processes such as carbon cycling in the tropical rainforests of Panama. 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. Student training is an integral part of the project. Collaboration with the Kentucky Science Center will result in the production of a Podcast highlighting this research, and public discussions with project participants in a Science Café format. Ecologists consistently list lightning as a source of tropical tree mortality, yet supporting data are remarkably scant. This project will systematically quantify lightning effects on tropical trees and lianas on a forest-wide scale in real time. The work will integrate information from field ecology, physics, and plant electrophysiology to answer three basic questions: What is the extent of lightning-caused tree mortality across a lowland tropical forest landscape? Are some trees or tree species especially susceptible to, or resistant to, the damaging effects of lightning? Do lianas function as lightning rods, protecting their host trees against lightning damage? Field work will be conducted in Panama at one of the best-studied tropical forest sites in the world. The methodology includes the installation of automated electronic sensors for monitoring strike events over large expanses of forest canopy. This project will also deploy an experimental lightning induction device - the Balloon Originating Lightning Trigger - to experimentally manipulate strike events to trees and lianas on isolated islands. Results of this work will fundamentally transform our understanding of tropical forest dynamics by quantifying lightning effects across the landscape and uncovering key interactions between lightning, lianas, and trees. In a practical context, this project will also reveal potentially confounding effects of communications towers and canopy cranes on tree mortality rates. This proposal is co-funded by the Division of Environmental Biology and the Physics of Living Systems program in the Physics Division.