Meet the tree that likes being struck by lightning
Lightning resistance appears to offer a competitive advantage.
Lightning and trees don’t usually mix. The intense electrical charge delivered by a lightning strike can obliterate most foliage, especially in tropical regions where research suggests more than 800 million trees are destroyed each year due to lightning strikes.
But a new study suggests that in some cases, lightning might benefit certain trees and provide a competitive advantage.
The Lightning-resistant tree: Dipteryx oleifera
A team of researchers, led by Evan Gora, a forest ecologist at the Cary Institute of Ecosystem Studies, noticed a Dipteryx oleifera tree standing tall and largely undamaged following a lightning strike in Panama in 2015, surrounded by more than a dozen trees that were destroyed in the incident. Their recent study, published this week in New Phytologist, examines 93 trees that had been struck by lightning in central Panama. The team found that while most trees were severely damaged, and that 64 percent died within two years of the strike, Dipteryx oleifera trees displayed minimal damage. Nine of these trees were directly struck by lightning, and all survived, suffering only minor damage.
Also known as the eboe, choibá, tonka bean or almendro, Dipteryx oleifera is native to Honduras, Nicaragua, Costa Rica, Panama, Colombia, and Ecuador. (Cary Institute of Ecosystem Studies
Dipteryx oleifera, also locally known as the eboe, choibá, tonka bean or almendro, is native to Honduras, Nicaragua, Costa Rica, Panama, Colombia, and Ecuador. Its wood is used in construction, and its edible, almond-flavoured seeds are sold in markets.
During the dry season, the tree's fruit and seeds act as an important food source for rainforest animals.
Why Dipteryx oleifera survives
The research team found the lightning strikes didn’t just spare the Dipteryx oleifera trees; it seems to give them a competitive advantage. When lightning struck these trees, nearby vegetation suffered.
According to the study's authors, each lightning strike to a Dipteryx oleifera tree killed approximately 9.2 neighbouring trees due to the electricity traveling between branches or vines.
This creates more space and resources for the Dipteryx oleifera. The trees also benefit from strikes because it helps remove parasitic vines called lianas, which can reduce light and nutrient availability.
Drone data revealed Dipteryx oleifera trees were typically about four metres taller than neighbouring trees, likely because lightning had wiped out surrounding vegetation.
The team suggests that the species' unique height and broad crown might make it more likely to attract lightning strikes. Dipteryx oleifera trees are 68 percent more likely to be struck by lightning than trees with average-sized crowns and height, the study notes.
"Estimates suggest individual Dipteryx oleifera trees are directly hit by lightning every 56 years, on average. And since the trees can live for hundreds or even more than a thousand years, they are expected to survive these blasts multiple times over the course of their long lives. One of the Dipteryx trees in our study was struck twice in just five years," reads a statement by the authors.
This lightning tolerance allows boosts the tree's ability to produce offspring by about 14 per cent.
In the long term, the lightning-strike tolerance of these trees could play a key role in forest planning and restoration efforts.
Given that lightning events are increasing in many regions due to climate change, these findings could point planners toward choosing to re-populate damaged forests with more lightning-resistant trees, which could enhance resilience to increasing storm frequency.
Header image: Edited by Cheryl Santa Maria for The Weather Network.