The Ecological Effects of Lightning in a Tropical Forest

Lightning is a common source of disturbance in many tropical forests, but its effects on tropical plants and forest dynamics remain poorly understood. In 2014, we established a unique lightning monitoring system in the Barro Colorado Nature Monument. Data from 93 strikes showed that lightning is an important agent of mortality for the largest trees in this forest and, on average, each strike kills 5.3 trees within 13 months. Mechanistic models indicate that large trees are most likely to be directly struck, and the probability of subsequent death varies interspecifically. Lightning is responsible for 20.1% of new gap area formed, and 16.1% of woody biomass turnover in this forest annually. Although lightning frequency is relatively high in the BCNM, field observations suggest that the per-strike effects are similar in other tropical forests. This ongoing research is revealing that lightning, although often overlooked, has important ecological effects in tropical forests.