Date of Award
Master of Science
Henri D. Grissino-Mayer
Sally P. Horn, Yingkui Li
Tree growth is a function of many environmental variables, and it is possible to detect differences between natural and human-related factors on tree growth. Radial growth of trees in one year and in subsequent years that follow is influenced not only by climate and other overarching multi-year processes, but also by pulse disturbance events. On December 22, 2008, an embankment at an impoundment for wet storage of fly ash at the Kingston Fossil Plant, Harriman, Tennessee collapsed, releasing 4,434,400 cubic meters of coal ash into the Clinch and Emory Rivers, impacting aquatic life as well as terrestrial flora and fauna. My study assesses the effects of coal ash on tree growth on two particularly impacted islands (Island 1 and Island 2) in the Emory River. I collected increment cores from 106 trees on Island 1 and from 20 trees on Island 2, totaling 126 trees and 143 increment cores. After excluding problematic cores that were too short, too decayed, or too broken, a total of 44 increment cores were analyzed for growth suppressions. No growth suppression events were detected that would indicate adverse effects from the coal ash spill. Possible explanations include : (1) ring widths alone may not be the best evidence of suppression; (2) it could be too early to detect the impact of the spill on tree growth with only three years of tree growth; (3) growth release from competition on the TVA islands could have compensated for any growth suppression; (4) all trees that died or suffered major damage were physically removed by TVA; (5) water level fluctuation and flood potential for the trees growing on the TVA islands could have masked or disrupted the disturbance signal from the spill; (6) soils on Island 2 could have been supplemented with high levels of nutrients that could have enhanced tree growth instead; and (7), the Kingston Ash Spill could have had no detrimental effect on tree growth.
Garland, Niki Ann, "A Dendroecological Evaluation of the Effects of Coal Ash on Tree Growth, Kingston Fossil Plant, Harriman, Tennessee, U.S.A.. " Master's Thesis, University of Tennessee, 2013.