Analysis of yellow birch and rhododendron foliage in Great Smoky Mountains National Park for total mercury

Analysis of yellow birch and rhododendron foliage in Great Smoky Mountains National Park for total mercury

Air -- Pollution

Mercury -- Environmental aspects

Rhododendrons -- Analysis

Yellow birch -- Great Smoky Mountains National Park (N.C. and Tenn.) -- Analysis

Ritter, Richard Lee

2008

Bacon, J. Roger

http://rightsstatements.org/vocab/CNE/1.0/

application/pdf

manuscripts (documents)

Text

61787

https://southernappalachiandigitalcollections.org/object/61787

Limited to on-campus users

Great Smoky Mountains National Park, an International Biosphere Reserve on the border of North Carolina and Tennessee, receives winds from the west that transport anthropogenic emissions from the Tennessee, Ohio and Mississippi River valleys and industrial cities of the Southeast and Gulf states. The height and physical structure of the mountains tend to trap and concentrate the air currents entering it. Coal-fired power plants, which are a known source of atmospheric pollutants including SO2, NOx and Hg, in the Tennessee River valley could contribute a significant portion to the amount atmospheric pollution that has been documented within the park. Numerous studies have shown that forested landscapes can be a major receptor of atmospheric mercury via wet and dry deposition and foliar uptake of atmospheric mercury. In this study, yellow birch (Betula alleghaniensis) and rhododendron (Rhododendron spp.) foliage was collected in the fall of 2005 and the spring of 2006 to determine whether (1) foliar total mercury concentrations showed an increasing temporal trend (2) total mercury deposition was greater at higher elevations within the park, and (3) total mercury deposition was greater on the western slopes of the park. Samples were air-dried, ground, acid-digested, and analyzed via CVAAS for total mercury. There was a two-fold difference between the spring (0.04 � 0.01�g/g) and the fall (0.08 � 0.02 �g/g) foliar Hg concentrations for the deciduous species, which was consistent with the literature, but there was no difference in concentrations for the evergreen species (0.04 � 0.01 �g/g and 0.04 � 0.01 �g/g, respectively), probably because it had reached an equilibrium point between foliar and air mercury concentrations. Based upon foliar Hg levels, there was no substantial influence upon Hg deposition by higher or lower elevations within the park. Foliar Hg levels for the deciduous species were found to be greater below an elevation of 762 m (spring, 0.05 � 0.02 �g/g; fall, 0.09 � 0.03 �g/g) and lower at elevations above 762 m (spring, 0.04 � 0.01; fall, 0.04 � 0.01 �g/g). These differences between foliar Hg levels of the lower and higher elevations was probably due though to the increased time of exposure to air Hg concentrations that the foliage received. There was no difference between foliar Hg concentrations of the evergreen foliage for the lower and higher elevations. Based upon foliar Hg levels, there was no significant difference between the foliar concentrations of both the deciduous and evergreen species that were located on the western and eastern sides of the park. The lack of any noteworthy discrepancy between foliar Hg levels of the higher/lower elevations or the western/eastern sides of the park signifies that foliage was not the best choice of a sampling media for this study. A more expansive study, sampling precipitation, throughfall, litterfall, and foliage, would seem to be more appropriate.

2015-06-08

All rights reserved. For permissions, contact Hunter Library Digital Collections, Western Carolina U, Cullowhee, NC 28723

Great Smoky Mountains National Park (N.C. and Tenn.)

13086 KB(file size)

x, 73 leaves(pages)

Western Carolina University Restricted Electronic Theses and Dissertations