【摘要】 通过对沙柳5个种源苗木叶片不同月份稳定碳同位素组成(1δ3C)的测定,研究不同种源沙柳δ13C值的特点,试图找出影响δ13C值季节变化的关键环境因子。结果表明:沙柳碳同位素值在-26.753‰~-29.915‰之间变化,其中,乌审旗和榆林种源1δ3C值较高,表明在该试验条件下具有较高的水分利用效率;叶片与枝条相比,δ13C值在6月和8月差异明显,达到0.930‰~2.469‰;而枝条的碳同位素值差异较小,为0.032‰~0.838‰;沙柳δ13C值在不同月份间有显著性差异,6月δ13C值明显高于8月;在将各环境因子分离开的情况下,主要研究了大气相对湿度对植物的1δ3C值季节变化的影响,结果显示,δ13C值随大气相对湿度的降低而偏重。更多还原

【Abstract】 By measuring the values of stable carbon isotope in leaves and branches of Salix psammophila from five provenances,in this paper the characteristics of δ13C values of different organs of Salix psammophila and the relationship between the δ13C values and the environmental factors under natural conditions are researched.The results show that the δ13C values of Salix psammophila vary in a range from-26.753‰ to-29.915‰,in which the δ13C values of Salix psammophila from the provenances in Wushen Bonner and Yulin are high,which reveals that the water use efficiency under the experimental conditions is high.The δ13C values of leaves in June are significantly different from that in August,and the difference is as high as 0.930‰～2.469‰.Compared with leaves,the difference of δ13C values of branches in these two months is not so high,and it is only 0.032‰～0.838‰.Under the conditions of separating air relative humility from other environmental factors,it can be concluded that air humility is an important environmental factor resulting in the seasonal variation of δ13C values of Salix psammophila plants,and the δ13C value is reduced with the decrease of air relative humility.更多还原