ENTS, Larry, Don,
I have seen the same spiraling pattern in a wide variety of tree
None of the explanations presented in the article make much sense to
They have not even demonstrated that trees tend to spiral in one
more than another. There is no common point of reference to say
direction the tree is spiraling. If a tree is spiraling clockwise as
down at it from above, then looking at it standing the grain would
to the right and down to the left.
The first thing to do would be to note the species of the tree,
location, and direction of spiral, Once you had a decent data set,
some analysis of the information could be made.
If I were to guess, and it is a guess, I would think the
is a genetic trait and not one developed on the fly in response to
wind direction ad the direction of the sun. Certainly it is not
the Coriolis effect on something as small as a tree trunk. My guess
why the tree grain spirals is that it is to provide additional
in response to wind stress, I think the twisted grain would be
response to a wind than would a straight grained tree. The tree
twist in response to winds rather than snap. There is no single
of weakness as is formed by the structure of the parallel grains,
is equally strong with the grain spiraling around the trunk. The
may not be in every specimen of a tree depending on its own genetic
and could require some triggering stress to develop.
We need some field data and a structural engineer to look at the
of the spiral grain.