Dendroclimatology of Pinus resinosa at Lac Hébécourt, NW Québec Ana, Eddie, Holly, Pam, Rita, Tiffany with lots of help from Dave and Matt

OBJECTIVES Establish a chronology of earlywood, latewood, and total ring width in Pinus resinosa Compare ring width chronology from Lac Hébécourt with 2 chronologies from Ontario Examine relationships between climatic variables and our ring width chronologies

SITE DESCRIPTION Lac Hébécourt Islands 12, 14, and15 (SW portion of lake) Topography Steep--> gentle Soils Thin over bedrock Island vegetation Spruce, fir, red pine, cedar, and paper birch

METHODS 2 cores/tree x 30 trees from three islands (#12, 14, 15) Cores sanded and crossdated COFECHA ARSTAN Correlation Analysis

Inter-ring relationships r=0.97 r=0.65 r=0.49

Comparisons with other chronologies r=0.14 r=0.06 r=0.51

r = 0.18 Time series of summer precipitation and latewood index

r = 0.11 r = 0.70

Average Temperature EW LW

Precipitation EW LW

r = r = 0.70

CONCLUSIONS Successfully crossdated Pinus resinosa in Lac Hébécourt, Québec Established a 216 year chronology ( ) for the area Chronology does not compare closely with other established chronologies in region

CONCLUSIONS Correlation between ring widths and regional climate strongest with nearby climate data Strongest correlations between ring width indices and climatic data were: (1) latewood index and late summer precipitation (positive) (2) earlywood index and winter precipitation (negative)

FUTURE DIRECTIONS Obtain better localized climate data (longer series) Climatic reconstruction will be difficult due to the conflicting climate response of winter and summer precipitation Control of measurement error Complete core analysis Further analysis of the residual and autoregressive chronologies could be explored Compare chronologies with other species in the region for indication of pointer years