The Weather Notebook: Stressed Out Trees

Stressed Out Trees
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Hi I'm Bryan Yeaton and this is the Weather Notebook.

The Northeast has been suffering through a drought. Foresters in the region are worried about its impact on the trees which cover nearly 90% of the northern New England states. The older bigger trees, says Peter Lammert of the Maine Forest Service, are at the greatest risk because of how deep their roots extend.

PL: For years and years and years farmland was plowed and the tree roots are able to put their roots down to that layer, but because of the deposition of minerals in the soil at that plowpan layer the roots can't get through that. It's like a super-hard hardpan.

The wear and tear on them is showing.

PL: The trees are stressed and it's a cumulative effect now manifesting itself in areas where the water levels perfectly fine, but the trees are showing really bad drought stress characteristics.

The critical period for their well being is during the spring.

PL: When the trees put on that spring flush is when they use the majority of the water they'll use all year long and if it's not there it will be interesting to see if the trees will put out a restricted number of leaves or smaller leaves.

That doesn't necessarily mean the trees will die, according to forester Gordon Moore.

GM: It usually takes several stressors to kill a tree. Several years of drought probably won't kill trees in and of themselves, but it will pre-dispose them to other types of insect attacks and other things.

Doug Sanborn, our assistant producer, helped with this report. The Weather Notebook is a production of the Mount Washington Observatory. The program is supported in part by Subaru of America and The National Science Foundation.