Spatial-temporal variation of water use efficiency in three species of sand-fixing shrubs on the Ordos Plateau
Aims To evaluate the adaptability of Salix psammophila,Artemisia ordosica and Caragana korshinskii to different hydrothermal gradients.Methods In this paper,fixed sample plots were established in the areas of Dalad Banner and Uxin Banner,Ordos City and Jingbian County,Yulin City,respectively,to study the carbon stable isotope composition(δ13C)and water use efficiency(WUE)of the leaves of the above three types of sand-fixing plants during the months of July to September,and to analyze the relationships between the WUE of the different types of sand-fixing plants and air temperature,precipitation and aridity index(AI).Important findings The results showed that:(1)The δ13C and WUE values were highest in C.korshinskii,and lowest in A.ordosica,and these values were significantly higher in July than in August and September;(2)for Salix psammophila,leaf δ13C and WUE did not exhibit a systematic trend with the increase in AI,while in Dalad Banner,where AI was the highest,leaf δ13C and WUE were significantly higher than Uxin Banner and Jingbian County in C.korshinskii and A.ordosica;the results of multifactorial ANOVA showed that the plant species and the spatial differences in which they were located had the greatest influence on plant δ13C and WUE;(3)The results of linear regression analysis showed that air temperature,precipitation and AI significantly affected WUE,except for C.korshinskii WUE,which had no significant effect on air temperature changes.among them,C.korshinskii WUE was the most sensitive to changes in AI,S.psammophila was more sensitive to changes in air temperature,while WUE of A.ordosica had a smoother response to changes in the above environmental factors.
sand fixing shrubcarbon stable isotopewater use efficiencyaridity indexOrdos Plateau
万方数据
维普
