HEAVY METAL ANALYSIS IN RED OAK (QUERCUS RUBRA) POPULATIONS FROM A MINING REGION IN NORTHERN ONTARIO (CANADA): EFFECT OF SOIL LIMING AND ANALYSIS OF GENETIC VARIATION

Understanding the dynamic of metals in soil and plants and population diversity in Northern Ontario is essential in determining progress toward ecosystem sustainability in reclaimed sites. The objectives of the present study were to assess the levels of metal content in soils and their accumulation in red oak plants from limed and unlimed sites. Genetic variation in red oak populations from the Northern Ontario region was also analyzed. The levels of soil acidity was lower in limed areas compared to un limed sites, an indication of the prolonged beneficial effect of liming 20 to 30 years ago on soil toxicity. The levels of total metals were very high for most elements, but the proportion of metals that were bio available and readily available to plants was very small. The enrichment factors were16.78, 4.98 and 2.94 for total arsenic, copper and nickel, respectively. The Translocation Factor (TF) values for available metals from soil to branches were high. There was more metal accumulation in leaves compared to branches. The degrees of genetic variability in red oak populations from limed and unlimed areas were compared using ISSR markers. The levels of polymorphic loci were moderate to high ranging from 44 to 65%. There were no significant differences in polymorphisms between areas that were limed and unlimed. Overall the red oak populations in stressed areas in Northern Ontario are sustainable.