Everyone has heard the old safety tip: “don’t stand under a tree during a thunderstorm”, based upon the likelihood that the tallest objects are the ones most likely to be struck. Turns out there is more to being struck than just being tall.
According to some studies, certain trees are struck by lightning more than others. Oaks are by far the most likely trees to be hit, and I support that with personal observations. Whenever I see a tree damaged by lightening, most of the time it’s an oak. Other trees that seem to be hit often are elm, ash, yellow poplar, and pine, but none approach the consistency of oak. The least likely tree species to be struck include beech, birch, holly, and maples. It may only be coincidental, but smooth barked trees are the ones least hit, while the rough barked ones are more often struck.
Why a certain tree is prone to lightning strike seems to be a matter of how good of a conductor of electricity it is. Those that have a central taproot extending into groundwater are more likely to be hit than trees with shallow roots. Trees that are tall, growing in the open, bordering woods or along a stream have higher odds to being struck.
How much damage lightning inflicts on a tree varies from none to blowing the top out of it. Trees are damaged far worse if they are struck before it rains. If hit after rain begins, the water on the bark can provide a conductive surface for electricity and prevent the interior of the tree from being damaged.
Hundreds of lightning fatalities occur each year, so thunderstorms should be taken seriously when they pop up rapidly during the hot summer months. Here are some safety rules:
1. Seek shelter indoors when a storm builds up. Usually the high winds and dark skies will give you ample warning to get to a safe place. Don’t bathe or shower during a storm, and don’t use the phone.
2. If driving in a car during a storm, stay in it. The metal exterior will prevent lightning from getting inside the car.
3. If a bad storm catches you away from shelter, lie prone on the ground near a ditch or embankment. Try to avoid areas with tall trees.
4. Swimmers and boaters should get out of the water as soon as they see a storm coming. Being on the water during thunderstorms is very dangerous.