A dendrochronological and dendrochemical study was undertaken near the village of Kuujjuaq, northern Quebec. Changes in climate, radial growth and mineral nutrition of trees, as well as the contamination in Mn and Zn of tamarack and black spruce forests of the region during the last forty years were investigated. A growth model based on climatic variables was produced for each species. The regional climate didn't show any steady trend of increase in temperature and precipitation with time. However, the 1953-1964 decade was the warmest one and the 1964-1973 decade received the most precipitation. Radial growth of both species have probably increased during the investigated period. Growth of larch was primarily associated with May and June precipitation (R$ sp2$ = 0.134) when spruce growth was associated with spring temperature and July and August evapotranspiration (R$ sp2$ = 0.352). Wood chemistry (concentration, burden, and elemental ratio) suggests a stable soil fertility in base cations during the last forty years as well as a stable or increased availability of Zn during the last decade. More extensive research, in terms of number of sites and variables studied could confirm the observed trends in growth, soil fertility, and Mn and Zn availability in this part of northern Quebec.

Cote, Benoit (Supervisor)