Mercury (Hg) research in Ontario has centered on aquatic environments since fish can be
a significant source of methylmercury for humans. Interactions between terrestrial and
aquatic environments in regards to the Hg cycle have received less attention. This study
focuses on the role of trees as a source and/or sink of Hg to the environment and the ap-
plicability of deciduous trees as biomonitors for Hg. Leaf, bark and wood core samples
were taken from a variety of deciduous species including Acer spp. (sugar, silver and red
maple), Quercus spp. (red oak), Populus spp. (eastern cottonwood), and Salix spp. (willow)
mainly from the Dorset and Kingston, ON regions. Examination of seasonal variation of
Hg concentrations ([Hg]) in leaves indicated that average autumn leaf Hg ranged from 17–
45 ng/g and differed significantly among species. Leaf [Hg] increased with the growing
season and roughly corresponded to regional atmospheric [Hg]. Microspatial trends in
leaf [Hg], such as position on a branch, may increase variability. Tree cores from contami-
nated and reference sites in the Kingston area showed that although dendrochronological
techniques are not appropriate for estimating historical atmospheric Hg, they are useful
for estimating the total Hg burden of a single tree. Populus and Salix, had the greatest
bark and wood [Hg] with maximums reaching 18 ng/g. This was significantly higher than
more inland trees such as Quercus and Acer, with maximum values of 7 and 1.2 ng/g for
bark and wood [Hg]. Individual, average sized trees in this study contained a total of
0.4–2.6 mg of Hg. This study will provide forest and watershed managers with a better
understanding of the importance of trees in the Hg cycle and the contribution of leaf and
wood Hg to litterfall and waterbodies in southern Ontario. / Thesis (Master, Biology) -- Queen's University, 2007-12-18 23:48:21.97
| Identifer | oai:union.ndltd.org:LACETR/oai:collectionscanada.gc.ca:OKQ.1974/950 |
| Date | 20 December 2007 |
| Creators | Siwik, Eden Isabel Helen |
| Contributors | Queen's University (Kingston, Ont.). Theses (Queen's University (Kingston, Ont.)) |
| Source Sets | Library and Archives Canada ETDs Repository / Centre d'archives des thèses électroniques de Bibliothèque et Archives Canada |
| Language | English, English |
| Detected Language | English |
| Type | Thesis |
| Format | 3665551 bytes, application/pdf |
| Rights | This publication is made available by the authority of the copyright owner solely for the purpose of private study and research and may not be copied or reproduced except as permitted by the copyright laws without written authority from the copyright owner. |
| Relation | Canadian theses |
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