Growth response of conifers to climatic variability in the Northern Canadian Rocky Mountains

Dendroclimatological methods were used to explore the response of conifers to climatic variability in the Northern Canadian Rocky Mountains. White spruce (Picea glauca) and subalpine fir (Abies lasiocarpa) ring-width chronologies were developed for an old growth forest in the Kwadacha Wilderness Provincial Park. Standard dendrochronological techniques were used to prepare and measure tree-ring cores. The ring-width series were standardized and averaged to create a master chronology for each species. Response function analysis, Pearson\u27s correlation analysis, and partial correlation analysis were used to explore the relationships between climatic variability and tree-ring width. The ring-width chronologies were compared with a 16-month window of air temperature and precipitation data spanning the period from May of the previous year through July of the current growing season. The chronologies were also compared with monthly indices of the Pacific Decadal Oscillation (PDO), to examine the influence of the PDO on radial growth. White spruce ring-width series are positively correlated with summer air temperature, and negatively correlated with spring temperature and summer precipitation. Subalpine fir ring-width series are positively correlated with July and December air temperature, and negatively correlated with summer precipitation, spring snowpack, and temperature during the previous summer. Subalpine fir ring-width series are also positively correlated with the annual winter-spring PDO index