Tree Arches / Tree Bows

[RodRoddy]

I find tree arches or tree bows quite peculiar.  Besides weather, or branches growing vertically atop the arch/bow, what causes trees to arch or bow?

Thank you for taking the time to answer my question.

[beenthere]

Welcome to the forum.
Several things can cause a tree to bow. Available light causes my white oak to bend over toward the opening in a pasture across the fence line. Ice storm will sometimes weigh young trees down and they do not straighten back up, thus grow bent over. Limbs will grow up from the bent stem.

Some trees lose a root-hold from a washout or creek erosion, and tip. Likely not what you are referring to here. Wind may also uproot trees causing them to tip. If far enough they may bend over if they continue to grow.

A few of the things.  Most are probably due something in their life to cause this to happen.

[Ianab]

Two different sort of situations.

One is the stump is vertical, and something pushes a flexible sapling over and caused it to grow horizontal. (snow, wind, another tree falling on it)

The other is that a sapling is completely pushed over and partly uprooted, and then straightens itself up continues to grow vertically.

Both give you a bowed log, but in different directions.

After a few decades whatever caused the original deformation is long gone but the tree is "set" in that shape. A sapling is flexible and able to be "trained", a mature tree is solid and holds that shape.

Ian

[thecfarm]

Also cutting the trees around them will cause this too. Some trees will reach for the light if the small ones are growing around big,tall trees. Than remove the big trees and the tall,small ones can not stand upright alone.
Welcome to the forum RodRoddy. Is this happening on your land? I kinda take care of my land and I cut these down for firewood. I feel they will never really amount to money in my pocket as a sawlog.

[WDH]

There is a hormone, auxin, that is produced by the growing meristem (bud at the tip) that regulates the position of the stem.  If a tree is pushed out of the vertical by some physical force, natural or unnatural, this hormone will stimulate growth in such a way that the stem will begin to straighten at the point of bud growth, causing the bow in the stem as the new growths straightens up.

If a stem grows out of vertical to the light, say a hole in the canopy, once the growing tip reaches the clear light, this hormone will stimulate growth in such a way that the tip will straighten, leaving the "bow" behind.  Down here, cherry is very shade intolerant and will grow toward the available light.  As a result, there is a lot of sweep in forest grown cherry where the tree is not in the dominant canopy position.

[RodRoddy]

Thank you all for the welcome and taking the time to answer my question.  The answers you've provided were very enlightening.  To answer your question, "thecfarm", this is not occurring on my land.  Seeing bowed trees on my hike the other day caused me to ponder the question. 

Within Forestry, is there a proper name for a bowed or arched tree?  When Googling, the only thing I came across was the word, "arcuate."  Are they called arcuate trees?  Or, do they go by another name?

[WDH]

"Arcuate" refers to the curve at the tip of a leaf to form an elongated point.  Dogwood is a good example of an arcuate leaf where the point at the end (tip) of the leaf looks like someone grabbed the point of the leaf and pulled it out to extend it.

In the wood business, what you are describing as "bow" is usually referred to as "sweep" in a log. 

[Okrafarmer]

Around here, many cherries and especially sourwoods grow either bowed over or at an angle. In Maine, the gray birches would bow over.

[Magicman]

Welcome to the Forestry Forum, RodRoddy.