黄土高原刺槐叶片⁃土壤生态化学计量参数对降雨量的响应特征  

Response characteristics of Robinia pseudoacacia leaf and soil ecological stoichiometric parameters to precipitation in the Loess Plateau

作　　者：苏卓侠 苏冰倩 上官周平[1] SU Zhuoxia;SU Bingqian;SHANGGUAN Zhouping(State Key Laboratory of Soil Erosion and Dryland Farming on the Loess Plateau,Northwest A&F University,Yangling 712100,China)

机构地区：[1]西北农林科技大学黄土高原土壤侵蚀与旱地农业国家重点实验室,杨凌712100

出　　处：《生态学报》2020年第19期7000-7008,共9页Acta Ecologica Sinica

基　　金：陕西省林业科学院科技创新计划专项(SXLK2020⁃0101);国家重点研发课题计划(2016YFC0501605);国家自然科学基金(41771549)。

摘　　要：以黄土高原10个典型样点的20年刺槐人工林为研究对象,测定了样地中刺槐叶片碳(C)、氮(N)、磷(P)含量,以及0—10 cm和10—20 cm土层土壤的主要理化指标,探讨了黄土高原刺槐叶片—土壤生态化学计量特征参数随水分梯度的变化规律。研究结果发现:①随着降水量增加,刺槐叶C、N含量呈增加趋势,叶片P含量无一致性规律。②0—10 cm土层中土壤SOC、TN、TP、铵态氮含量以及C∶P和N∶P均随降雨量增加呈逐渐增加趋势,而C∶N比变化不明显。③刺槐叶片C、N、P及其化学计量比与土壤化学计量比相关性较弱,但叶片N、P与土壤铵态氮、速效磷等速效养分含量呈显著正相关(P<0.05)。本研究叶片N∶P>16,说明黄土高原刺槐生长主要受P元素限制,且随着降水的增加,土壤P养分的限制加强。This study sampled 20⁃year⁃old Robinia pseudoacacia plantations at 10 typical sites on the Loess Plateau.We determined the C,N and P concentrations in Robinia pseudoacacia leaves and various physical and chemical indexes of 0—10 cm and 10—20 cm soil layers,and further explored the variations in the ecological stoichiometric parameters of the leaf—soil system along a water gradient on the Loess Plateau.The results showed that:①leaf C and N concentrations increased with increasing rainfall,but there was no clear trend for leaf P concentration along a rainfall gradient.②Soil organic carbon(SOC),total nitrogen(TN),total phosphorus(TP),and ammonium nitrogen concentrations and soil C∶P and N∶P ratios increased with increasing rainfall in 0—10 cm soil layer,but soil C∶N has no obvious change.③There were no significant correlations between plant and soil C,N,P concentrations and C∶N,C∶P,N∶P ratios,but leaf N and P concentrations were significantly positively correlated with soil available phosphorus and ammonium concentrations.The result of leaf N∶P>16 indicated that the plant was under P limitation on the Loess Plateau.Additionally,the soil P limitation increased with increasing rainfall.

关 键 词：生态化学计量参数 降雨量 刺槐 黄土高原 

分 类 号：S792.27[农业科学—林木遗传育种]