Does Climate Affect Wood Hardness?
Reader Charles Hammond of Kingston, Massachusetts, writes with a question about local timber growth:
“Where I grew up in England, local timber was a workout to saw by hand. The woods tended to be oak, hawthorn, beech, and a few other species. It made sense to me, when I was a boy and a young man, that trees that grew slowly in the cold, north of the 50th parallel, should be tough, hard, and strong! But then my father introduced me to a ‘redwood’ grown in Swaziland, which his staff had felled and sawn with 8'-long, two-man saws. He told me that it took the two chaps all day to saw through the trunk, and they had to sharpen the blade twice. That wood was hard!
“Burmese teak, meranti, and mahogany were among the very hard and tough woods that came from the tropics. Near where I live now, the Powder Point Bridge in Duxbury has stood in tidal water for more than 100 years. It is built of some kind of African wood. Shouldn’t hot, humid, and wet conditions produce rapidly growing trees with wide rings that won’t require much more than a good steak knife to cut? Why do the hardest woods seem to be grown where the weather makes one feel like a wet rag?”
The basic question that Mr. Hammond seems to be asking is whether trees produce wood of a certain hardness in response to climate signals. The answer is a qualified yes. The kind of wood a tree produces has evolved over millions of years in response to many factors, most notably climate, species competition, soil conditions, and light exposure.