Chen 2012: Qinghai spruce in middle Hexi Corridor, China
Abstract: Seven different tree-ring parameters (tree-ring width, earlywood width, latewood width, maximum density, minimum density, mean earlywood density, and mean latewood density) were obtained from Qinghai spruce (Picea crassifolia) at one chronology site in the Hexi Corridor, China. The chronologies were analyzed individually and then compared with each other. Growth–climate response analyses showed that the tree-ring width and maximum latewood density (MXD) are mainly influenced by warm season temperature variability. Based on the relationships derived from the climate response analysis, the MXD chronology was used to reconstruct the May–August maximum temperature for the period 1775–2008 A.D., and it explained the 38.1% of the total temperature variance. It shows cooling in the late 1700s to early 1800s and warming in the twentieth century. Spatial climate correlation analyses with gridded land surface data revealed that our warm season temperature reconstruction contains a strong large-scale temperature signal for north China. Comparison with regional and Northern Hemisphere reconstructions revealed similar low-frequency change to longer-term variability. Several cold years coincide with major volcanic eruptions.
Temperature reconstruction from tree-ring maximum latewood density of Qinghai spruce in middle Hexi Corridor, China
Feng Chen, Yu-jiang Yuan, Wen-shou Wei, Shu-long Yu and Zi-ang Fan, et al.
THEORETICAL AND APPLIED CLIMATOLOGY
Volume 107, Numbers 3-4, 633-643, DOI: 10.1007/s00704-011-0512-y
Samples were taken at one tree-ring site (39°03′ N, 100°43′E, site code TLC) in the Dongdashan Nature Reserve. To minimize non-climatic effects on tree growth, only trees with no injury and disease were sampled. One 5 mm core and two 12 mm cores were taken from each tree with increment borers. In total, 25 cores (5 mm) and 50 cores (12 mm) were collected from 25 trees. The sampling site was at 3,150–3,200 m elevation a.s.l.; on northern slopes, it was with an inclination of 15–20°.