Photos by Michael Allen / Winnipeg Free Press
Downed ash tree on a city boulevard.
Standing ash tree stub.
This summer has certainly been one where a great number of trees, both urban and rural, have been brought down or have ended up scattered over roads, yards and even buildings.
I have a keen interest in studying the images of downed trees and branches that appear on nightly news reports and what I am seeing are great chunks of tree trunks and a multitude of branches of various sizes strewn everywhere.
I carefully study what has fallen out of trees. Yes, there are numerous branches, but if you were to look very carefully you would see broken branches and tree trunks that exhibit decayed wood along with hollow wood among the debris piles.
In fact, as I observe the nature of tree wood that has been massively damaged I begin to see a pattern. The visible debris contains pieces of decayed hollow wood and branches. Rarely does one see healthy wood in the branches and trunks in the debris field after a storm passes. If a tree is healthy and relatively free of visible weaknesses, it will likely have no problem staying in one piece and alive.
Some trees, such as ash, develop vertical cracks along parts of the outer surface of the trunk. These cracks do not necessarily mean the tree is going to split apart. Other factors, such as the origin of the cracks, depth of the cracks into the wood and the distribution of the cracks along the tree trunk must be considered as well.
Examine your trees for any signs of weakness, especially in the trunk and at the base of the tree. If in doubt, have two licensed Manitoba arborists independently examine the tree.
In a previous article, I wrote about the value of having the interior wood of a tree "examined" by my resistograph. The graphical readout of interior tree condition can be very helpful in deciding if a tree may be safe or not.
Michael Allen M.Sc.F., RPF (ret’d) is a consulting urban forester, tree diagnostician and certified arborist. He owns Viburnum Tree Experts. He can be reached at 204-831-6503 or 204-223-7709, or at viburnumtrees@shaw.ca His web site is www.treeexperts.mb.ca
