In a bizarre phenomenon, the tonka bean tree has evolved to harness electricity from lightning strikes to protect itself against enemies, granting it a surprising reproductive advantage and allowing it to thrive in its environment.
For trees, lightning strikes are often a matter of life and death. However, one tree species has evolved to harness electricity from lightning to protect itself against its enemies.
The Tonka Bean Tree: A Master of Electrical Defense
The tonka bean tree (Dipteryx oleifera) is a towering tree native to the rainforests of Panama that can grow up to 130 feet tall and live for hundreds of years. While most trees suffer from lightning strikes, which can be fatal, the tonka bean tree has developed an extraordinary defense mechanism.
The Tonka bean tree, also known as Dipteryx odorata, is a tropical tree native to Central and South America.
Its beans are highly prized for their unique flavor and aroma, often used in perfume and confectionery production.
The tree's wood is also valued for its durability and resistance to rot.
In the wild, Tonka bean trees can grow up to 100 feet tall, with a spread of around 50 feet.
They thrive in humid climates with high temperatures, making them ideal for tropical regions.
How Lightning Shapes Forests and Tree Lives
Researchers have long been interested in understanding how lightning affects forests and the lives of the trees that inhabit them. However, the positive influence of lightning on ecosystems is largely understudied compared to other causes of tree mortality, such as drought and fire.
To investigate this phenomenon, scientists created a system to pinpoint lightning strikes in Panama’s Barro Colorado Nature Monument using an antenna array and drones. By combining this data with four decades of tree plot records, the researchers were able to form a clear picture of how lightning affected specific areas.
A lightning strike is a massive electrostatic discharge that occurs between the clouds and the ground.
It is caused by the buildup of electrical charges in cumulonimbus clouds, which can reach voltages of up to 1 billion volts.
According to the National Weather Service, 'lightning strikes the Earth about 50 times per second, with an average of 100 lightning storms occurring worldwide each day.'
Lightning can strike from up to 10 miles away and can travel at speeds of up to 270,000 kilometers per hour.
The Surprising Benefits of Lightning Strikes
Between 2014 and 2019, the researchers documented nearly 100 instances of various species of trees being directly struck by lightning. Notably, all ten tonka bean trees that were hit by the powerful electric discharges survived with negligible damage. In contrast, 78 percent of the parasites, a species of woody vine known as lianas, were wiped out by the lightning purges.
Moreover, the researchers found that the tonka bean tree’s biomass was reduced by over two metric tons in each strike, while its neighbors’ biomass was annihilated. This suggests that living next to a tonka bean tree is a hazardous situation, with a substantial risk of death compared to other large trees in the forest.
The Electrical Advantage
One reason for this advantage may be the tonka bean tree’s architecture, which appears to be selecting for more frequent lightning strikes. With a height 30 percent taller and a crown 50 percent wider than others, it seems to dare the heavens above to unleash their fury.
As a result, the tonka bean tree experiences a fourteen times boost in fecundity – ‘a stunning reproductive advantage that sets it apart from other trees.’ This remarkable defense mechanism has allowed the tonka bean tree to thrive in its environment, where lightning strikes are an integral part of its survival strategy.
