A dendroclimatological reconstruction of climate since AD 1700 in the Mt. Waddington area, British Columbia Coast Mountains, Canada

The radial growth characteristics of five high-elevation coniferous tree species were established from sites located within the southern British Columbia Coast Mountains, Canada. The sites are located on valley slopes ranging from 760 to 1860 m asl and were found close to the terminus of contemporary glaciers, predominantly occupying sites with southern and western aspects. Increment core samples were collected from Pinus albicaulis Engelmann (whitebark pine), Abies lasiocarpa [Hooker] Nuttall (subalpine fir), Tsuga mertensiana (Bongard) Carriere (mountain hemlock), Pseudotsuga menziesii (Mirbel) Franco (Douglas-fir), and Chamaecyparis nootkatensis (D. Don in Lambert) Spach (yellow-cedar). After a common radial growth response was detected within and between each species, species-specific master tree-ring chronologies were constructed to express the regional signal. Correlation analyses indicate that radial growth in this setting is negatively impacted by summer air temperature of the previous growth year, positively influenced by November air temperature of the previous growth year and air temperature of the current growing season (mostly July), and negatively influenced by larger than normal April 1 snowpack depths. These relationships were validated and models of temperature (January, July, summer) and snowpack (April 1) were developed back to the 17th century. Common modes of variability found occurring between 2 and 8 years, at approximately 20-23 years, and approximately 120 years are believed associated with North Pacific Ocean-atmospheric circulation systems (ENSO, PDO) and with perturbations in solar activity.