摘要
利用在祁连山东段冷龙岭青海云杉森林上限采集的树轮样芯,建立3个树轮宽度年表,与气象资料的响应分析发现,上年9月到当年4月的降水量是冷龙岭上限云杉生长的限制因子。基于多元回归模型重建本区1848年以来的降水量,重建模型的方差解释量达到45%,并用交叉检验验证了模型的稳定性。低通滤波序列显示冷龙岭过去近160 a经历了4次干期：1853—1857年,1877—1880年,1919—1931年,1974—1975年和4次湿润期：1869—1872年,1888—1892年,1950—1956年,1970—1972年。通过与祁连山中、西段的干旱序列对比得出,在较长的时间尺度上祁连山山区东、西降水的低频变化具有一致性。MTM（Multi-taper method of spectrum analysis）周期分析显示冷龙岭降水量存在40 a左右和2~3 a的显著周期,研究结果表明,ENSO循环和东亚季风对冷龙岭降水量有着重要影响。
On the basis of tree-ring cores collected of Picea crassifolia from the timberline in Mt.Lenglonglin,three width chronologies were developed.Correlation analyses showed that the limiting factor of tree growth in the eastern part of Mt.Qilian was the precipitation from prior September to current April（PSA）.Therefore,precipitation series was reconstructed during last 160 years according to a multiple regression model,and model＇s explained variance was 45%.The reconstructed drought series had obvious low-frequency and high-frequency variations,and contained four severe dry spells（occurred in 1853 to 1857,1877 to 1880,1919 to 1931,1974 to 1975） and four significant humid spells（during 1869 to 1872,1888 to 1892,1950 to 1956,1970 to 1972）.Compared with the researches in the middle-western Qilian Mountain,we found that precipitation fluctuation in eastern Mt.Qilian was agreement with that in middle and western Mt.Qilian in the long time scale.The dominant periods calculated by MTM spectrum analysis were 2 to 3 year and about 40 year.These results showed ENSO and East Asian Monsoon had a significantly influence on precipitation variability in eastern part of Mt.Qilian.
出处
《山地学报》
CSCD
北大核心
2011年第1期12-18,共7页
Mountain Research
基金
国家自然科学基金(No.50879033
40901021)
国家基础科学人才培养基金项目(J1030519)共同资助~~
关键词
树轮
冷龙岭
干旱
ENSO
tree-ring
Mt.Lenglonglin
drought
ENSO
