Wednesday, October 13, 2010

Dead Ash

There are always some new dead trees in the woods. Sometimes it’s a wonder that the woods can persist given the annual numbers of newly dead trees. I found a clump of dead and dying ash trees along one ridge top. The cause of the tree deaths usually remains a mystery. That’s partially due to the multiple factors that constantly put stress on the trees. Insects, disease, shallow soil, weather, air quality, impurities in rain water, lightning strikes and various other factors combine to weaken the health of a tree, making it very difficult to assign one factor as the cause of death.

These days, when any ash tree dies, people automatically assume that the Emerald Ash Borer got it. I gave this Blue Ash a careful going over and could find no evidence of any borer damage. That crooked trunk suggests that this tree has seen some stressful moments during its life.

The exposed wood seems free of borer damage. Emerald Ash Borer would have left distinctive tracks from the larvae that feed just below the bark.

The inner side of the bark is also clean. It’s nice to know that the trees aren’t being killed by an exotic borer, but it’s little consolation to avoid borer infestation by having the ash trees die before they can become infested.

Some of the trees are showing dead tops, but have new branches emerging lower down on the trunk. When trees react in this fashion, they are not likely to recover. There is often a temporary period of increased vigor which is followed by a dramatic decline. This sequence may occur several times, but the final outcome is death of the tree.

The dying trees are located around the perimeter of a small opening in the tree canopy. It’s possible that these trees are suffering from a cloud-to-ground lightning strike to this clearing. From the house, I’ve watched so many lightning strikes to this ridge that it’s a wonder there are any trees left. Many of the trees bear the scars of their lightning encounters. It’s not hard to believe that a well placed bolt of lightning could mean the end of a few of these trees.


  1. My parents lost a few ash trees on their property with a similar look. I never considered lightning, I thought it might be a series of dry summers.

    Do you know if ash trees are early trees in the succession from field to forest, that is are they some of the first to colonize old fields?

  2. Hi, Roberta. Ash species are some of the first to invade old fields. They colonize so readily that they are often not planted as part of reforestation projects. Project planners count on the ash to naturally introduce itself into the stand.

  3. Ash seedlings are by far the most common woody 'invasives' I'm dealing with in a low-maintenance area behind my house and next to the woods (hoping to establish warm-season grasses in the area instead and just walk through once in a while with a weed whacker or Roundup to keep the woodys at bay).

    Do you have EAB in the area yet?

  4. Ted - EAB has been confirmed about 20 miles east of here.