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Upper forest border regional ring width (red) compared with April-September temperature reconstructed from maximum latewood density (black) (22). The density series is an average of 2 grid points (37.5°N, 117.5°W; 37.5°N, 107.5°W) and was fitted with a 2-year moving average (t−1 and t) before plotting. Bold solid lines are center-plotted 5-year moving averages. The 2 series are completely independent.
