Table 1. Periods covered by crossdated measurement time series of TRW and VLA and statistics of datasets for the studied sites for the common period of 1910–2010: number of crossdated trees and samples; range, mean and standard deviation (St. dev.) of measurements; mean sensitivity (SENS), autocorrelation (AC), inter-series correlation (IC), Gleichläufigkeit (GLK) and expressed population signal (EPS) of cross-dated time series (IC and EPS were calculated for detrended series).
TRW, 10 mm VLA, 104 μm2
SKD AUC AGL SKD AUC AGL
Period covered by
measurements 		1902–2013 1907–2013 1906–2013 1902–2013 1910–2013 1909–2013
Number of crossdated
trees (samples) 		7 (13) 16 (29) 10 (18) 6 (12) 15 (25) 10 (20)
Min 0.42 0.23 0.15 0.99 0.96 0.97
Max 5.30 7.96 6.99 7.35 8.40 8.88
Mean 2.26 2.93 2.09 3.41 2.71 3.10
St. dev. 0.93 1.01 0.81 1.00 0.92 0.99
SENS 0.18 0.22 0.22 0.17 0.16 0.17
AC 0.83 0.64 0.74 0.74 0.80 0.76
IC 0.48 0.43 0.46 0.27 0.22 0.29
EPS 0.86 0.89 0.87 0.69 0.75 0.83
GLK 0.68 0.69 0.69 0.62 0.61 0.60
1

Fig. 1. Mean time series (A and C) and residual chronologies (B and D) of tree-ring width (TRW) and mean area of earlywood vessel lumen (VLA) of studied sites and sample depth of the datasets (E) for sites near Šķēde (SKD), Auce (AUC) and Aglona (AGL). Curves have been produced based on crossdated mean time series of trees.

2

Fig. 2. Pearson correlation coefficients calculated between climatic factors – mean monthly temperature (bars) and precipitation sums (lines), and residual chronologies of tree-ring width (TRW) and mean area of earlywood vessel lumen (VLA) for sites near Šķēde (SKD), Auce (AUC) and Aglona (AGL) for the period from 1910 to 2010. Significant coefficients at α = 0.05 are in dark grey (bars) or indicated by asterisks (lines). Months of the year prior to tree-ring formation are in uppercase.

3

Fig. 3. Pearson correlation coefficients calculated between mean monthly temperature (T), precipitation sums (P) and residual chronologies of tree-ring width (TRW) and mean area of earlywood vessel lumen (VLA) for 50-year moving intervals for sites near Šķēde (SKD), Auce (AUC) and Aglona (AGL). Significant correlations are indicated by bold lines. Climatic factors that had significant correlations in > 15 intervals are shown. The dates represent the last year of moving intervals. Months of the year prior to tree-ring formation are in uppercase. Note that the plotted climatic factors, their sequence and encoding differ. View larger in new window/tab.