Foliage of three trembling aspen clones differing in O3 tolerance from Rhinelander, Kenosha and Kalamazoo were examined for 24 elements in the year 2001 and they were analyzed by INAA at reactor IBR-2, by AAS Varian 400 and by elemental analyzer LECO SC 132 and SP 228. In the fofliage of trembling aspen we found no statistically significant difference in the concentration of 22 elements except for K and Ni between clones. For the concentrations of elements between localities we found statistically significant difference for Al, Ba, Ca, Cd, Cl, Co, Cu, La, Mo, Na, Ni, Pb, Sm, Sr and Zn

Atmospheric carbon dioxide (CO2) and ozone (O3) are increasing by 1-2% per year and are expected to double by the year 2100 compared to the end of the last millennium. Carbon dioxide at twice the current atmospheric concentrations has the potential to increase the productivity of forest trees while increasing ozone is expected to cause significant reductions in growth. The present study was undertaken to investigate the effects of CO2 and O3, singly or in combination, on growth and allocation of two European silver birch (Betula pendula Roth) clones under field conditions to verify the future predicitons in regard to silver birch. Our data show that growth of clone 80 was benefitted by ambient CO2 singly and in combination with ambient O3. Clone 4 was more responsive to ambient O3 than clone 80 which is opposite to results from previous pot experiments with these clones

Technology options involving the use of natural and accelerated bioremediation systems to treat complex mixtures of aromatic wastes would be a useful addition to current remediation strategies. The approach outlined in this paper would focus on harnessing the potential of a key detoxification enzyme, glutathione-S-transferase (GST) as part of an accelerated phytoremediation system to detoxify aromatic pollutants in soil and ground water. Major efforts will include the clarification of GST detoxification activity by characterizing the enzyme in a series of phenolic and azo-dye-tolerant phytoremediation candidates (e.g. elite clones of thyme), and the development of methods to manipulate the GST detoxification pathway in elite plant clones to accelerate the detoxification of aromatic pollutants. The information provided by the GST characterization studies could be used to develop significant new phytoremediation systems based on manipulated GST biotransformation pathways in elite plant clonal systems tolerant to highly polluted environments. One major advantage of the new phytoremediation systems would be their potential to perform in highly contaminated environments by providing a favorable rhizophere zone for microbial degradation of aromatics along with an enhanced GST-linked detoxification pathway