Air Quality and Forests
Updated 3/2/06
   Work done by Prof. Robert Bruck at NC State U.  showed that trees on our mountain ridges are experiencing severe die off  at least partly due to air pollution.  If you have visited Clingman's Dome in the Smokys or Mount Mitchell, or Mount Hardy, you will be very aware of the death and destruction.  Even red spruces, not affected by the Balsam Wooly Adelgid attacking the Fraser Firs, are dying.   Poor air quality not only leads to acidification of trout streams, but also to slowing of tree and crop growth.  It is surprising that farmers and timber growers do not perceive air quality as an issue impacting them.  The acidification process is insidious.  At first, soil minerals neutralize the acid in rain and particles falling from the sky, but as these minerals are used up in this process there comes a point when acidity increases dramatically, making life impossible for the bugs that decompose leaf duff and recycle soil nutrients for use by plants, and for the mycorhizal fungi living on tree roots and working with them to make soil nutrients available to the tree.  In sufficiently acid soils aluminum ions toxic to trees become soluble and are taken up by trees along with water.  As the tree  weakens it becomes more susceptible to boring beetles, fungi and other pests that it would normally shrug off. 

   One measure of air pollution, aside from actual measurements of ozone, nitrogen oxide, and sulphur dioxides, and particulates in the air, is visibility, the distance one can see to the horizon.  Sometimes visibility is restricted by cloud and fog, but the grayish haze we see so often now in the mountains is attributed to sulphate and nitrate particles from air pollution.   It is quite shocking to learn that ozone levels in our mountains often rivals that of urban areas like Charlotte.  Much of the pollution comes from coal-burning power plants in Tennessee and the Ohio Valley, but some is local, from our own power plants, and from automobiles and trucks.

    For those more interested, see the excellent book edited by Harvard Ayers, Jenny Hager, and Charles Little, "An Appalachian Tragedy", published by Sierra Club Books in 1998.

     The Pisgah National Forest has installed a digital camera to look at Cold Mountain in the Shining Rock Wilderness.  It is updated once per hour (when it is working) and also, in the summer, gives air quality information.
    The National Park Service has also installed a digital camera, at Look Rock in TN, which gives frequent updates of the view from there, plus ozone and particulate measurements.


digital camera views from Look Rock, TN, and Purchase Knob, NC, in the Great Smokies National Park.

View of Cold Mountain in Shining Rock Wilderness of Pisgah National Forest

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