Table 2. Correlation coefficients between the seasonally aggregated climate data and the four residual chronologies, the RES-chronology based PC#1 series, the corresponding first-order difference series of PC#1, and the 5-year smoothed series of PC#1 over their common periods (Meteorological data cover 1951–2011; PDSI covers 1951–2005).

	HS	HMS	MS	LS	PC#1	1st differenceseries	5-year smoothed series
p11-c2Tem	−0.02	−0.06	−0.07	−0.10	−0.06	−0.16	0.08
p11-c2 Tmax	−0.06	−0.10	−0.11	−0.15	−0.11	−0.21	0.04
p11-c2 Tmin	0.05	0.01	−0.00	−0.02	0.01	−0.10	0.16
c5–6 Tem	−0.25	−0.25	−0.29*	−0.30*	−0.27*	−0.32*	−0.16
c5–6 Tmax	−0.33*	−0.32*	−0.34**	−0.35**	−0.34**	−0.43**	−0.13
c5–6 Tmin	−0.06	−0.06	−0.07	−0.12	−0.08	0.03	−0.07
c5–6 Pre	0.48**	0.51**	0.51**	0.51**	0.51**	0.52**	0.43
c5–6 PDSI	0.46**	0.44**	0.49**	0.50**	0.48**	0.60**	0.36
p7-c6 Pre	0.56**	0.59**	0.60**	0.61**	0.60**	0.63**	0.58*
p6-c5 Pre	0.52**	0.54**	0.55**	0.58**	0.56**	0.59**	0.55*
p8-c7 PDSI	0.33*	0.30*	0.35**	0.39**	0.35**	0.40**	0.49
p7-c6 PDSI	0.28*	0.25	0.31*	0.35*	0.30*	0.33*	0.49
p7-c6 RH	0.30*	0.36**	0.36**	0.36**	0.35**	0.57**	−0.16

Tem = mean temperature; Tmax = maximum temperature; Tmin = minimum temperature; Pre = precipitation; PDSI = Palmer Drought Severity Index; RH = relative humidity; p means previous year; c means current year; HS means the higher-site; HMS means the higher-mid site; MS means mid-site; LS means lower-site. ** means correlation is significant at the p = 0.01 level, * means correlation is significant at the p = 0.05 level. The significance testing of the 5-year smoothed series was based on the adjusted degree of freedom method described by Bretherton et al. [51].