Getting hit by lightning is good for some tropical trees

Getting zapped with millions of volts of electricity may not sound like a healthy activity, but for some trees, it is. A new study, published in New Phytologist, reports that some tropical tree species are not only able to tolerate lightning strikes, but benefit from them. The trees may have even evolved to act as lightning rods.

The research was led by Evan Gora, a forest ecologist at Cary Institute of Ecosystem Studies. Gora studies how lightning impacts biodiversity and carbon storage in Panama’s tropical forests.

Lightning kills hundreds of millions of trees per year. But in 2015, while working in Panama, Gora and his colleagues came across a Dipteryx oleifera tree that had survived a strike with little damage – even though the jolt had been strong enough to blast a parasitic vine out of its crown and kill more than a dozen neighbouring trees.

'Seeing that there are trees that get struck by lightning and they’re fine was just mind blowing,' Gora recalled. Over time, the team encountered other D. oleifera trees thriving after getting hit, so they decided to take a closer look.

Scientists had previously suspected that some trees evolved to tolerate lightning, but evidence to back it up was lacking. In 2022, Gora and colleagues demonstrated for the first time that trees differ in their ability to survive getting hit by lightning. Their New Phytologist paper is the first to show that trees can actually benefit from these electric jolts.

Using a unique lightning location system, the team tracked the outcomes of 93 trees that had been struck by lightning in Barro Colorado Nature Monument in central Panama. For two to six years after the strike, the team measured tree survival rates, crown and trunk condition, number of parasitic vines or lianas, and neighbouring tree mortality. The study included nine directly struck D. oleifera trees, and compared them with 84 other trees that had been struck.

All nine D. oleifera trees survived direct lightning strikes with only minor damage. In contrast, directly struck trees of other species were badly damaged, losing 5.7 times more leaves from their crowns, and 64% died within two years.

When each D. oleifera tree was zapped, an average of 9.2 neighbouring trees were killed as the electricity travelled between adjoining vines and touching branches, or jumped across small gaps between trees. Lightning strikes also decreased D. oleifera's parasitic liana infestations by 78%, further reducing competition for light and nutrients.

Read the full press release from the Cary Institute of Ecosystem Studies.