中文摘要：

位于西藏高原的东北部分的 Lenglongling 山(LLM ) ，属于东方亚洲夏天季风(EASM ) 的一个边缘的区域并且对季风动力学敏感。在 LLM 从 Picea crassifolia 的六个地点开发的二张树戒指宽度年表被采用学习地区性的干旱可变性。关联和时间的关联分析证明在二张年表和自我校准的帕尔默干旱严厉索引(sc_PDSI ) 之间的关系越过时间重要、稳定，表明在为在这个区域的干旱条件建模的 sc_PDSI 的力量。基于关系，吝啬的 sc_PDSI 从 1786 ～ 2013 为时期被重建。干燥条件在 1817-1819， 1829-1831， 1928-1931 和 1999-2001 期间占优势。相对湿的时期为 1792-1795 和 1954-1956 被识别。与另外的十四降水 / 干旱的空间关联重建了在以前的研究的系列表明在西北中国的干旱区域，潮湿条件的长期的可变性在在十的规模(1791-1954 ) 的 1950 年代前是同步的。在 EASM 的西北的边缘，大多数所有选择了重建最好特别在干燥时期期间，在低频率的变化的一致性显示类似的地区性的潮湿变化和气候的类似的模式在这个区域在树生长上强迫。

英文摘要：

The Lenglongling Mountains （LLM） located in northeastern part of the Tibet Plateau, belong to a marginal area of the East Asian summer monsoon （EASM） and are sensitive to monsoon dynamics. Two tree-ring width chronologies developed from six sites of Picea crassifolia in the LLM were employed to study the regional drought variability. Correlation and temporal correlation analyses showed that relationships between the two chronologies and self-calibrated Palmer Drought Severity Index （sc_PDSI） were significant and stable across time, demonstrating the strength of sc_PDSI in modeling drought conditions in this region. Based on the relationships, the mean sc_PDSI was reconstructed for the period from 1786 to 2013. Dry conditions prevailed during 1817-1819, 1829-1831, 1928-1931 and 1999-2001. Relatively wet periods were identified for 1792-1795 and 1954-1956. Spatial correlations with other fourteen precipitation/drought reconstructed series in previous studies revealed that in arid regions of Northwest China, long-term variability of moisture conditions was synchronous before the 1950s at a decadal scale （1791-1954）. In northwestern margin of the EASM, most of all selected reconstructions had better consistency in low-frequency variation, especially during dry periods, indicating similar regional moisture variations and analogous modes of climate forcing on tree growth in the region.