北京西山老龄树记载的森林干扰历史

张启, 程雪寒, 王树芝

History of forest disturbance recorded by old trees in Xishan Mountain, Beijing

ZHANG Qi, CHENG Xue-Han, WANG Shu-Zhi

图5 北京西山老龄树标准化年表与区域气候要素滑动相关关系。滑动相关分析窗口设置为30年。P, 年降水量; PDSI, 帕尔默干旱指数; T, 年平均气温。纵坐标中字母“c”代表当年。

Fig. 5 Moving correlation coefficients between the standard tree-ring chronology and climatic factors of sampled old trees in Xishan Mountain, Beijing. The sliding correlation analysis window is set to 30 years. P, annual precipitation; PDSI, Palmer drought severity index; T, mean annual air temperature. “c” before the numbers at the y-axis represent the month of current year.