祁连山林线区域青海云杉种群对气候变化的响应

Response of Picea crassifolia Population to Climate Change at the Treeline Ecotones in Qilian Mountains

研究祁连山林线区域青海云杉种群结构、年轮生长及林线位置对气候变化的响应。结果表明:在区域气候变暖的背景下,青海云杉林线种群1～30龄的幼龄个体数量最多,占总数的80.9%;100年来林线种群密度大约增加了23倍,但林线位置并没有发生明显变化;年轮分析得出,气候变暖导致近30年来林线树木径生长明显增加,青海云杉树木年轮指数与当年夏季、秋季以及上一年夏季平均气温显著正相关,与上一年秋季及当年6月份的平均气温呈极显著正相关。

In this paper, the response of the ecological dynamics and tree-growth to climate change was investigated at the treeline ecotones in Qilian Mountains. The results showed that the young plants （1-30 a age） occupied 80.5% of the total number of trees at the treeline ecotones. The population density increased by 23 times, however the tree limit position in the treeline ecotones was not significantly changed during the past 100 years. In addition, the radial growth of Picea crassifolia showed a steady increase trend in the past 30 years. According to the relationship between radial growth and climate, the radial growth of trees was positively and significantly correlated with mean temperature of the summer and fall, as well as the previous summer and fall, especially the previous fall and June.