西昆仑山两种针叶树种径向生长及其对气候变化的响应

利用西昆仑山的雪岭云杉和昆仑圆柏树芯样本，建立其树轮宽度年表。通过分析两种针叶树种树木径向生长特征与气候要素的相关关系，探讨了树种间的树木生长气候响应异同及响应关系的稳定性。结果表明：研究区域内的雪岭云杉和昆仑圆柏年表间存在显著正相关。两种针叶树种在1994年气温突变前树轮宽度年表指数和基部断面生长增量（BAI）呈上升趋势，在气温突变后年表和BAI则呈下降趋势，并且昆仑圆柏的树木径向生长速率高于雪岭云杉。与气候要素的相关性分析结果表明，雪岭云杉径向生长与上年生长季（5—6月和8—10月）和当年生长季（3—6月和10月）气温呈显著负相关，而昆仑圆柏径向生长与上年10月和当年生长季前期（4—6月）气温呈显著负相关；两者均与当年春季降水呈显著正相关。滑动相关分析结果显示，上年和当年生长季气温对两个树种树木径向生长的负响应在增强，特别是在当年生长季前期更为显著。此外，当年生长季前期降水对树木径向生长的促进作用也在增强。在有可能的气候突变年份（1994年）之后，两种针叶树种对气温和降水的响应敏感性均有所增强，并且雪岭云杉对气温的响应敏感性强于昆仑圆柏，而对降水响应敏感性要弱于昆仑圆柏。

Radial growth of two coniferous species in the western Kunlun Mountains and its response to climate change

In this paper, the tree-ring-width chronologies of Picea schrenkiana and Juniperus jarkendensis in western Kunlun Mountains are developed based on their core samples. Radial growth-climate response and its stability were discussed by analyzing the radial growth characteristics of two coniferous species and their correlation with climate factors. The results show that there was a significant positive correlation between P. schrenkiana and J. jarkendensis chronologies in the study area The interannual change of the chronologies index of two tree-ring-width and basal area increments (BAI) shows a rising trend before the year of abrupt temperature change in 1994, while they show a declining trend after the year of abrupt temperature change. The tree radial growth rate of the J. jarkendensis is higher than that of P. schrenkiana. The results of the correlation between radial growth and climate change showed that the radial growth of P. schrenkiana was significantly negatively correlate with the temperature in the growing season of previous year (May-June and August-October) and the growing season of current year (March-June and October), while the radial growth of J. jarkendensis was significantly negatively correlate with the temperature in October of previous year and the early growing season of current year (April-June). Both of them are significantly positively correlated with the spring precipitation of current year. The results of sliding correlation analysis show that the limiting effect of temperature on the radial growth of the two tree species is enhanced in the growing season of previous year and current year, especially in the early growth season of current year. In addition, the promoting effect of precipitation on tree radial growth in the early growing season is also enhanced. After the possible year of abrupt climate change (1994), the response sensitivity of the two conifer tree species to temperature and precipitation was enhanced, and the response sensitivity of P. schrenkiana to temperature was stronger than that of J. jarkendensis, the sensitivity to precipitation was weaker than that of J. jarkendensis.