柴达木盆地东缘青海云杉树轮细胞结构变化特征及其对气候的指示

基于青海柴达木盆地东缘山地青海云杉生长上限的树轮样本，在获取树轮宽度数据的同时，获取了细胞特征指标，包括细胞个数和细胞大小，建立了树轮早材、晚材、整轮的细胞个数标准年表和细胞大小的最大值、最小值年表，并通过与附近茶卡气象站过去31年（1970—2000年）逐月降水量和温度的相关分析和响应函数分析，从细胞尺度探讨了青海云杉生长与外界气候要素的关系.结果表明：早材细胞个数与冬半年（上年10月至当年3月）温度之间呈正相关关系；晚材细胞个数除了与11月和12月最低温度呈显著正相关外，还与生长季中7月和8月平均温度呈显著相关关系；早、晚材细胞个数同时与7月的降水量呈显著负相关.早材细胞个数与5月的降水量呈正相关关系.对于早材最大细胞大小的年表来说，其变化与2月的降水量变化有很好的一致性，而晚材最小细胞的大小与8月降水量的变化同步.细胞个数和细胞大小不仅记录了树轮宽度所记录的温度变化信息，还额外记录了一定的降水信息，说明不同的树木生长指标能够记录不同的气候信息.利用同一地点同一树种不同类型的树轮指标，能够提取多种气候要素的变化信息，这对将来从同一样点的树轮资料中提取更丰富的气候信息以及发掘树轮气候学的潜力具有一定意义.

Variations of Picea crassifolia tree-ring cell structure and their implications to past climate in eastern margin of Qaidam Basin, Northwest China.

Tree-ring samples of Picea crassifolia were collected from the upper tree-line in the eastern mountainous area of Qaidam Basin in Qinghai Province. The tree-ring width and the cell number and size of the tree-ring were measured, and the standard chronologies for the early-wood cell number, late-wood cell number, total cell number of tree-rings, maximum cell size, and minimum cell size were constructed. By using correlation analysis and the response functions between cell characteristic indices and 1970-2000 climate factors at Chaka meteorological station which was close to the sampling site, the relationships between P. crassifolia growth at cell scale and climate factors were discussed. The results showed that the early-wood cell number was positively correlated to the wintertime temperature from previous October to current March, while the late-wood cell number was positively correlated to the minimum temperature in previous November and December and to the mean temperature in current July and August. Both the early-wood and the late-wood cell numbers were negatively correlated to the precipitation in July, and the early-wood cell number was positively correlated to the precipitation in May. The chronology of maximum cell size of early-wood was positively related to the precipitation in February, while that of minimum cell size of late-wood was positivelyrelated to the precipitation in August. It was concluded that the cell number and cell size could not only reveal the information of temperature change, which was recorded by tree ring width as well, but also provide additional information of precipitation. Since different types of tree-ring indices contained different climate information, multiple aspects of climate change information could be extracted from different tree-ring indices of the same species at the same site, and the cell level tree ring characteristics had great potential to supply the information regarding past climate.