The contributions of lightning to biomass turnover, gap formation, and plant mortality in a tropical forest

Lightning is a common source of disturbance, but its ecological effects in
tropical forests are largely undescribed. Here we quantify the
contributions of lightning strikes to forest turnover and plant mortality
in a lowland Panamanian forest using a real-time lightning monitoring
system. We examined 2195 lightning-damaged trees distributed among 93
different strikes. None exhibited scars or fires. On average, each strike
disturbed 451 m2 (95% CI: 365-545 m2), created canopy gaps of 304 m2 (95%
CI 198-454 m2), and caused 7.36 Mg of woody biomass turnover (CI:
5.36-9.65 Mg). Cumulatively, we estimate that lightning strikes in this
forest create canopy gaps equaling 0.39% of forest canopy area,
representing 20.1% of annual gap area formation, and are responsible for
16.1% of total woody biomass turnover. Trees, lianas, herbaceous climbers,
and epiphytes were killed by lightning at rates 8-29 times greater than
their baseline mortality rates in undamaged control sites. The likelihood
of lightning-caused death was higher for trees, lianas, and herbaceous
climbers than for epiphytes, and high liana mortality suggests that
lightning is an important driver of liana turnover. These results indicate
that lightning influences gap dynamics, plant community composition, and
carbon storage capacity in some tropical forests.

闪电是一种常见的干扰源，但其在热带森林中的生态效应大多尚未被描述。本研究利用实时闪电监测系统，量化了巴拿马低地森林中雷击对森林周转和植物死亡率的贡献。

我们调查了分布在93次不同雷击事件中的2195棵受雷击损害的树木，未发现任何疤痕或火灾迹象。

平均而言，每次雷击干扰面积达451平方米（95%置信区间（CI）：365-545平方米），形成冠层间隙（canopy gaps）304平方米（95%置信区间：198-454平方米），并导致7.36吨木质生物量周转（woody biomass turnover）（置信区间：5.36-9.65吨）。

累计来看，我们估计该森林中的雷击造成的冠层间隙总面积相当于森林冠层面积的0.39%，占年度间隙面积形成量的20.1%，并贡献了总木质生物量周转的16.1%。

树木、藤本植物、草本攀缘植物和附生植物因雷击死亡的速率，是未受干扰对照区域中其基线死亡率（baseline mortality rates）的8至29倍。

树木、藤本植物和草本攀缘植物因雷击死亡的概率高于附生植物，而藤本植物的高死亡率表明雷击是藤本植物周转的重要驱动因素。

这些结果表明，雷击会影响某些热带森林中的间隙动态（gap dynamics）、植物群落组成（plant community composition）和碳储存能力（carbon storage capacity）。