Why Are Oak and Fir Trees More Likely to Be Struck by Lightning Than Beech and Pine In a Thunder Storm?

Almost a century ago, a monthly journal, Country Queries and Notes, was first published.

In it, it was asked if oak and fir trees were far more likely to be struck by lightning than pines, and if beech is the tree least likely to attract a lightning strike.

This question attracted an enormous amount of interest from readers. Their responses were still arriving a year later.

Replies were compiled from many different sources and showed the following number of lightning strikes: oak, 484; poplar, 284; willow, 87; elm, 66; pine, 54; yew, 50; beech, 39; ash, 33; pear, 30; walnut, 22; lime, 16; cherry, 12; chestnut, 11; larch, 11; maple, 11; birch, 9; apple, 7; alder, 6; mountain ash, 2; and hawthorn, 1.

Only after further prompting from the editor did one reader admit to seeing a stricken sycamore. There were assertions that holly was never seen to be hit.

With no indication of the relative proportions of the trees present the list may appear meaningless, but it does look as if height has more relevance than species.

Arguments grew a little wearisome but there was some support for the view that trees with corrugated bark, and therefore traces of moisture, attracted more strikes than those with smooth bark.

It seems fairly clear, though, that it is best to assume what we all know already, lightning can strike anywhere.

The Forestry Commission’s most recent research paper on the subject states that oak, poplar, and Scots pine are the tree species most frequently damaged, with beech least likely to be damaged.

However, this is based on two surveys, each with relatively few records. The first was carried out between 1932 and 1935 and the second between 1967 and 1985, and there are some discrepancies, partly because the earlier survey included only obviously lightning-damaged trees, while the later one includes non-catastrophic damage, which is quite common and sometimes barely detectable.

North American publications also show beech, birch, and horse chestnut as relatively unlikely to be struck, compared with oaks, pines, and spruces, among others.

North America gets much more lightning than Britain and it is not uncommon for particularly valuable specimens to be fitted with lightning conductors in order to preserve them. To our knowledge a conductor has only once been fitted to a British tree, a particularly large cedar that was considered especially at risk.

Various theories have been advanced as to why some species are apparently struck more often, including the possibility that some conduct electricity better, either through the sap or because their rough bark retains more rainwater.

This would explain why beech, with its smooth bark, is less susceptible to strikes.

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