Analysis of temporal and spatial changes in vegetation cover using wavelet transform method in Wolong Natural Reserve Evaluation of temporal stability in tree growth-climate response in Wolong National Natural Reserve, western Sichuan, China Tree ring reconstruction of summer temperature variations over the past 159 years in Wolong National Natural Reserve, western Sichuan, China Influence of different detrending methods on climate signal in tree-ring chronologies in Wolong National Natural Reserve, western Sichuan, China