| Project Title |  |
| Metal accumulation in
coniferous and deciduous trees - Comparing dendrogeochemistry and phytogeochemistry near
the Horne Smilter (Rouyn)
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| Research Team | |
| M. M. Savard, Delta-Lab,
Geological Survey of Canada, Québec Geoscience Centre, Ste-Foy, Québec. P.I. Email: msavard@nrcan.gc.ca
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| Project Summary | |
| Demdrogeochemistry is a promising
environmental biomonitoring tool that has been applied to distinguish between natural and
anthropogenic sources of metals. The technique assumes that a tree ring;s metal content
reflects the geochemical and environmental conditions that prevailed during the year it
was formed. Trees can be regarded as biologic receptors as well as historical records of
metals in the environment because they grow at the geosphere-atmosphere interface over
several decades, even centuries. For these reasons, phytoavailability and cycling of
elements, including potentially-toxic metals, can be documented by studying the complete
tree system, i.e., soil composition, along with foliage and tree rings. However, the use
of dendrogeochemistry to address environmental issues has been hampered by the problem of
radiol mobility of elements with the stem (translocation). Accumulation levels in annual
growth rings and translocation effects vary with tree species. Before historical trends of
metal bioavailability in soils can be inferred from tree ring sequences, the significance
of metal contents and translocation effects in trees requires investigation. In the above
project, these problems will be addressed by comparing metal contents in leaf tissues and
in tree rings of the same year in arboreal species known to have different physiologic
behaviour, such as deciduous (popular) and coniferous (spruce) trees. The research work for 1998-99 will involve comparison of dendrogeochemical series of coniferous and deciduous trees in an area under stress due to atmospheric pollutants from a smelter.
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