内蒙古典型草原植物功能性状对刈割与氮添加响应的年际间差异性  

Interannual variations in the responses of plant functional traits to mowing and nitrogen addition in an Inner Mongolian typical steppe

作　　者：李旭 王佳智 马文红 杨雨 李翔宇 王明臣 刘新亮 胡锦香 王永慧 LI Xu;WANG Jiazhi;MA Wenhong;YANG Yu;LI Xiangyu;WANG Mingchen;LIU Xinliang;HU Jinxiang;WANG Yonghui(Ministry of Education Key Laboratory of Ecology and Resource Use of the Mongolian Plateau/Inner Mongolia Key Laboratory of Grassland Ecology/School of Ecology and Environment,Inner Mongolia University,Hohhot 010021,Inner Mongolia,China)

机构地区：[1]内蒙古大学生态与环境学院/蒙古高原生态学与资源利用教育部重点实验室/省部共建草地生态学国家重点实验室培育基地,内蒙古呼和浩特010021

出　　处：《草业科学》2024年第10期2389-2401,共13页Pratacultural Science

基　　金：国家重点研发计划项目(2023YFF0805600);国家自然科学基金项目(31960259);中国科学院战略性先导科技专项(XDA26010101-2)。

摘　　要：植物功能性状调控植物响应环境条件变化,但也因受其影响而具有生态系统间和年际间差异。本研究基于内蒙古典型草原4年的刈割与氮添加试验,分析探讨了植物功能性状对刈割与氮添加的响应及年际因素和试验处理对其的影响强度。研究对象包括羊草(Leymus chinensis)、克氏针茅(Stipa krylovii)、糙隐子草(Cleistogenes squarrosa)3种优势植物的植株高度、叶面积、叶片碳氮含量等10种功能性状。结果表明,刈割显著降低了植物的植株高度,且刈割、氮添加及二者结合的处理均提高了植物叶片的氮含量并降低了碳氮比。然而,刈割和氮添加对植物功能性状的可塑性影响很小。同时,研究发现植物功能性状及其对处理的响应存在显著的年际间变异性,这主要是由于降水量年际差异的潜在影响。这表明,增强的降水量年际波动会增加预测植物功能性状和植物功能响应的难度,而考虑土地利用方式背景有助于实现准确预测。Functional traits can regulate how plants respond to changes in the ambient environment;however,they can also be influenced by changes in the environment,resulting in variations among ecosystems and years.Based on a 4-year manipulative mowing and nitrogen addition experiment on a typical Inner Mongolian grassland,we analyzed and explored plant functional trait responses to mowing and nitrogen addition and analyzed the strengths and effect of both sampling years and treatments on these plant functional traits.This study focused on 10 plant functional traits,including plant height,leaf area,leaf carbon and nitrogen content,of three dominant species:i.e.Leymus chinensis,Stipa krylovii,and Cleistogenes squarrosa.The results indicate that mowing significantly reduced the height of the three species.Nitrogen addition alone,and in combination with mowing,increased the leaf nitrogen content in the dominant species.This led to a decreased leaf carbon-to-nitrogen ratio,but had almost no impact on the plasticity of the plant functional traits.Potentially because of the cross-year variation in precipitation,sampling years led to pronounced interannual variability in both plant functional traits and their responses to treatments.These results imply that accurately predicting the responses of plant functional traits may become increasingly challenging with increased interannual fluctuations in precipitation while considering the context of land-use practices could enhance accuracy.

关 键 词：内蒙古典型草原 植物功能性状 土地利用方式变化 养分富集 年际间差异 

分 类 号：S812[农业科学—草业科学]