Monday, August 30, 2010

Trees have stretch marks too!

Have you ever noticed the stretch marks on trees?

Trees grow in height as well as in diameter. Some trees, like the sycamore, allow for the increase in trunk diameter by shedding bark, an all too common occurrence in the spring in my neighborhood.  

Ash, elm and many other trees develop cracks in the bark that run up the trunk.  As new wood and bark is produced under the older outer bark, these cracks allow the tree to expand. 

Cracks also form in the bark when the trunk bends as you can see in the next photo.   

These cracks are normal.

1 comment:

  1. I'm wondering if you know any research on the formation of these normal lateral cracks from the tree bending? Also the rang of species it occurs in?

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