准噶尔盆地伊犁郁金香稳定碳同位素组成变化特征

选取准噶尔盆地古尔班通古特沙漠南缘9个样地中的伊犁郁金香（Tulipa iliensis）自然居群，通过测定各居群中伊犁郁金香的稳定碳同位素组成（δ^13C）、叶片和土壤中全氮、全磷、全钾以及水分含量，分析伊犁郁金香δ^13C值与上述因子之间的相互关系。结果表明：不同生境间伊犁郁金香δ^13C值差异不显著，水分利用方式可能受其基因型的控制而较为保守，同时在一定程度上也受生长环境中环境因子变化的影响，因而会有小的变幅：除了土壤中全钾含量之外，伊犁郁金香的叶片全氮、全磷、全钾、叶片水分含量以及土壤全氮、全磷和土壤水分含量在不同生境间均存在显著差异；其中伊犁郁金香叶片和土壤中的全氮含量与δ^13C值呈显著正相关：随着该植物叶片和土壤中水分含量的下降，伊犁郁金香δ^13C值显著增大，水分利用效率（WUE）明显提高。说明伊犁郁金香δ^13C值是植物的遗传学因子和环境因子共同作用的结果，其叶片及土壤中的氮素含量和有效水分含量是影响伊犁郁金香δ^13C值的关键因子。

Variation in the Stable Carbon Isotope Composition of Tulipa iliensis Regel in Junggar Basin

Tulipa iliensis is an important ephemerals in Junggar Basin in Xinjiang in China. In order to investigate how ephemerals respond to the distribution of water and nutrients, we measured stable carbon isotope composition （δ^13C） in leaves of T. iliensis collected from 9 natural populations in the southern edge of Gurbantonggut Desert in Junggar Basin. Meanwhile, total nitrogen, total phosphorus, total potassium and water content of leaves and soil are analyzed. The results show there are no significant variations in δ^13C values of T. iliensis among 9 natural populations. It means that δ^13C values of T. iliensis are mainly controlled by their inherent characteristics. And small changes of δ^13C values may attribute to growing environments. Regression analyses between δ^13C values and water and nutrients in T. iliensis indicate that δ^13C values are positively correlated with leaf total nitrogen content and soil total nitrogen content, negatively correlated with leaf water content and soil water content. It is apparently that leaf and soil total nitrogen content and water content contribute great impact on water use efficiency of T. iliensis in Junggar Basin. Furthermore, the role the soil plays might affect resource acquisition and influence nutrient cycling in arid systems.