Question
In my experience I have witnessed several birch trees being split by lightning, Is this common and if so, does anyone know why?
Answer
Tall trees, those growing alone in open areas, trees with roots in moist soils or those growing along bodies of water are most likely to be struck.
Though no species of tree is totally immune, some are definitely more resistant to lightning bolts than others. Birch, for example, is rarely struck, whereas elm, maple, oak and pine are commonly hit. The reason for the wide variation in susceptibility is not clear.
Some authorities attribute the variation to the composition of the trees. Trees high in oils (birch and beech) are poor conductors of electricity, whereas trees high in starch content (ash, maple, and oak) are good conductors. In addition, deep-rooted or decaying trees appear to be more subject to attack than are shallow-rooted or healthy trees
