【作者】 赵良菊； 肖洪浪； 刘晓宏； 陈克龙；

【Author】 ZHAO Linagju~1) XIAO Honglang~1) LIU Xiaohong~2) CHEN Kelong~3) 1)Shapotou Desert Reserch and Experiment Station,Cold and Arid Regions Environmental and Engineering Research Institute,Chinese Academy of Science,Lanzhou,Gansu,730000;2)Key Laboratory of Cryosphere and Environment,Cold and Arid Regions Environmental and Engineering Research Institute,Chinese Academy of Sciences,Lanzhou,Gansu,730000;3)Geographic Department,Qinghai Normal University,Xining,Qinghai,810008

【机构】 中国科学院寒区旱区环境与工程研究所沙坡头沙漠试验研究站； 中国科学院寒区旱区环境与工程研究所中国科学院冰冻圈与环境联合重点实验室； 青海师范大学地理与资源环境系；

【摘要】 通过对腾格里沙漠东南缘沙坡头人工固沙区油蒿和柠条叶片稳定碳同位素分辨率(Δ)和N 含量的测定,研究了不同种植方式下油蒿和柠条叶片Δ和N 含量的季节变化及其关系。结果表明:在不同种植方式下,两种植物的Δ与N 含量在不同月份之间均存在显著差异。油蒿叶片Δ极显著高于柠条的:在不同种植方式下,油蒿单种下Δ显著高于混种,柠条则反之。油蒿叶片N 含量极显著低于柠条的:不同种植方式下柠条叶片N 含量无显著差异,而单种油蒿叶片N 含量则显著低于混种。在Δ与N 含量的关系中,柠条叶片Δ与N 在两种生境、单种和混种下均极显著正相关,说明柠条叶片N 含量可以作为其Δ的替代指标;而油蒿叶片Δ与N 在单种下为正相关,混种及两种生境分别呈不显著正相关及弱的负相关关系,表明植物叶片Δ与N 含量的季节变化及其关系在不同微生境有所差异。更多还原

【Abstract】 By analyzing leaf stable carbon isotope discrimination(Δ)and N concentration of Caragana korshinskii(C.K)andArtemisia ordosica(A.O)under different planting arrangements in Shapotou,the authors investigated the variations of plant leafstable carbon isotope discrimination(Δ)and N concentration.The results show that the of C.K is higher significantly than that ofA.O;this means that the water use efficiency(iWUE)of C.K is higher than that of A.O.Under different planting regimes,theΔ of A.O with single planting is higher than that of mixed planting,and the C.K shows the opposite trend,namely,the Δ of C.K with single planting is lower than that of mixed planting.Compared with that of C.K,N concentration of A.O is significantlylow.There is no difference of N concentration between single and mixed planting in C.K.However,this difference is very signifi-cant in A.O and the N concentration with mixed planting is significantly higher than that of single planting(p=0.001).There e-xist significantly positive relationships between Δ and N concentration under the conditions of both planting regimes,single plantingand mixed planting,suggesting that the leaf N concentration of C.K may be a proxy of Δ.However,these relationships are not con-stant in A.O.更多还原