Reconstruction of Summer Temperature from Maximum Latewood Density of Pinus densata in West Sichuan
采用高山松最大密度重建川西高原近百年夏季气温

Having analyzed the tree ring width and maximum latewood density of Pinus densata from west Sichuan, we obtained the different climate information from tree-ring width and maximum latewood density chronology. The growth of tree ring width was responded principally to the precipitation in May, which might be influenced by the activity of southwest monsoon, whereas the maximum latewood density reflected the summer temperature (June-September). According to the correlation relationship, a transfer function had been used to reconstruct summer temperature for the study area. The explained variance of reconstruction is 51% (F = 52.099, p < 0.0001). In the reconstruction series: before the 1930s, the climate was relatively cold, and relatively warm from 1930 to 1960, and this trend was in accord with the cold-warm period of the last 100 years, west Sichuan. Compared with Chengdu, the warming break point in west Sichuan is 3 years ahead which shows Tibetan Plateau was more sensitive to temperature change. There was an evident summer warming signal after 1983. Although the last-100 running average of summer-temperature in the 1990s was the maximum, the running average of the early 1990s is below the average line and it was cold-summer; summer-drought presented in the late 1990s.