论文部分内容阅读
以大兴安岭北部根河、呼中和汗马冻土区落叶松和樟子松为样本,建立了五个树轮宽度年表,并计算获取了五个样点的树轮截面积指数(BAI)序列。树轮BAI-气候响应关系分析表明,气温为这一地区落叶松和樟子松生长的主要限制因子;但落叶松和樟子松对气候变化的响应存在差异。落叶松BAI与3月平均气温,樟子松BAI与前一年12月至当年4月平均气温均呈显著负相关。考虑到水热综合影响,落叶松BAI控制因子由1957-1990年与其呈显著正相关的1月份SPEI转变为1991-2013年与其呈显著正相关的1-4月SPEI和与其呈显著负相关的3月份平均气温;樟子松BAI控制因子则由1957-1990年与其呈显著负相关的2月和8月份平均气温转变为1991-2013年与其呈显著正相关的7月份降水量和6-7月SPEI。结果表明,在全球变暖背景下,水热环境改变使得冻土区树木生长限制因子发生变化。
Taking the Larix gmelini and Pinus sylvestris var. Mongolica in the root river, Huzhong and Hanmai permafrost regions in the northern part of the Daxinganling Mountains as examples, five tree-ring width chronologies were established and the tree-leaf cross sectional area index (BAI) sequence. Analysis of tree ring BAI-climate response showed that temperature was the main limiting factor for the growth of larch and Pinus sylvestris var. Mongolica in this region. However, the response of Larch and Pinus sylvestris var. There was a significant negative correlation between BAI of larch and average temperature of March, and the mean temperature of BAI of Pinus sylvestris var. Mongolica from December to April of the previous year. Taking into account the combined effects of hydrothermal and thermal stresses, the Larix principis-rupprechtii (BAI) control factor was significantly changed from January SPEI, which was positively correlated with it during 1957-1990, to January-April SPEI which was significantly and positively correlated with 1991-1993 and negatively correlated with it The average temperature in March; the control factor of Pinus sylvestris BAI was changed from the average temperature in February and August, which was significantly and negatively correlated with it from 1957 to 1990, to the July-June precipitation and the July-July precipitation with a significant positive correlation Month SPEI. The results show that under the background of global warming, the change of hydrothermal environment causes the change of tree growth restriction factor in permafrost regions.