Gary M. Lovett
Cary Institute of Ecosystem Studies
Collaborators:
Gary M. Lovett, Cary Institute of Ecosystem Studies
Kathleen C. Weathers, Cary Institute of Ecosystem Studies
Mary A. Arthur, University of Kentucky
Jacob Griffin, University of Wisconsin
The beech bark disease, which was introduced to North America from Europe, is caused by a combination of a scale insect and a fungus. The insect penetrates the bark of the trees to feed, and the tiny holes it leaves behind allow the fungus to become established. Once infected with the fungus, most trees die.
The disease affects nearly every beech tree in the Catskills, and it is especially prevalent in the mid-elevation forests (Griffin et al 2003). One of the effects of the disease has been a reduction in the Catskill's beech population, resulting in an increase in beech's major competitor, sugar maple. We have studied a sequence of stands that range from healthy mixed beech-maple forest to stands where once-dominant beech trees have succumbed to beech bark disease and been replaced by maples. We have found that as the disease progresses and the beech are replaced by sugar maple, there are associated changes in carbon and nitrogen cycling such as increased soil respiration, increased litter decomposition, and increased nitrate production (Hancock et al. 2008, Lovett et al. in press).
We are also studying several hundred plots in the Catskills of New York and the White Mts. of New Hampshire to understand the tree species change caused by the beech bark disease and its implications for carbon storage and nitrogen retention in the forest.
Four papers have been published so far, and others are in preparation.
- Lovett, G.M., M.A. Arthur, K. C. Weathers and J.M. Griffin. Long-term changes in forest carbon and nitrogen cycling caused by an introduced pest/pathogen complex. Ecosystems (in press).
- Hancock, J. E., M. A. Arthur, K. C. Weathers, and G. M. Lovett. 2008. Carbon cycling along a gradient of beech bark disease impact in the Catskill Mountains, New York. Canadian Journal of Forest Research 38:1267-1274.
- Lovett, G.M., C.D. Canham, M.A. Arthur, K.C. Weathers, and R.D. Fitzhugh. 2006. Forest ecosystem responses to exotic pests and pathogens in eastern North America. Bioscience 56:395-405.
- Griffin, J.M., G. M. Lovett, M. A. Arthur, and K. C.. Weathers 2003. The distribution and severity of beech bark disease in the Catskill Mountains, NY. Canadian Journal of Forest Research 33:1754-1760.
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