博斯腾湖滨柽柳(Tamarix ramosissina)生长对湖水位的敏感性

The Sensitivity of Ring Width of Tamarix ramosissina to Lake Level of the Bosten Lake

基于博斯腾湖1955—2012年湖水位变化资料,利用树木年轮法分析了博斯腾湖年和月水位变化与湖滨柽柳(Tamarix ramosissina)年轮生长关系,利用敏感度指数得出博斯腾湖滨柽柳年轮生长的敏感水位范围。结果表明:(1)1955—2012年博斯腾湖年平均水位经历了3个明显变化阶段,即1955—1987年下降至最低,1987—2002年上升至最高。受向下游生态输水影响,2002—2012年博斯腾湖水位快速下降。输水对博斯腾湖月平均水位和季节性水位变化有影响。(2)博斯腾湖滨柽柳年轮指数与当年的湖水位变化和前1年的湖水位变化均显著相关(p<0.05)。柽柳年轮指数与前1年10月至当年4月各个月份的湖水位表现出显著相关(p<0.05)。柽柳年轮指数与前1年冬季湖水位相关显著(p<0.05),与当年春季3—4月月平均湖水位相关性显著,与当年夏季和秋季湖水位的相关性不显著。(3)博斯腾湖滨柽柳年轮生长对月湖水位变化响应比较敏感。当湖水位在1045.3m时,柽柳年轮指数灵敏度指数(Sk)存在最低值;当湖水位在1 046.3m时,Sk出现最高值。

Annual and monthly level data of the Bosten Lake and the dendrochronology methods are used to analyze the relationship of lake level and ring growth of Tamarix ramosissina.A relationship formula between the ring index and the lake level is established.The sensitivity method is applied to analyze the sensitivity of the ring growth to the lake level.The results show that:(1)Bosten Lake level has three obviously change stages from 1955 to 2012.The level decreased from 1955 to 1987,and increased significantly from 1987 to 2002.However,the lake level began to decline from 2002 to 2012due to water transferring from the Boaten Lake to the lower reaches of the Tarim River.Water transfer also influences the monthly and seasonal lake level change of the Bosten Lake.(2)The ring index is correlated significantly with lake level in current and previous year(p<0.05).Furthermore,the correlation is significant between ring index and lake level from pervious October to current April(p<0.05).And the correlation is also significant between ring index and lake level from March to April in current year while the correlation is not significant from summer to autumn in current year.(3)The sensitivity of the ring index to the lake level change is significantly.The Skvalue of ring width appears minimum when lake level is 1 045.3m.The Sk value is maximum when the lake level is up to 1 046.3m.Thus,based on ring index sensitivity analysis,suitable sensitive lake level for protecting Tamarixcommunity is determined to be between 1 045.3and1 046.3m.