黄土高原草地灌丛化对土壤有机碳、氮磷养分及酶活性的影响  

Effects of Shrub Encroachment on Soil Organic Carbon,Nitrogen and Phosphorus Nutrients,and Enzyme Activity in Loess Plateau

作　　者：丁颖 刘小伟 郭梁 景煜都[2,3,4] 封俊豪 梁可 裴梦婷 熊千里 Ding Ying;Liu Xiaowei;Guo Liang;Jing Yudu;Feng Junhao;Liang Ke;Pei Mengting;Xiong Qianli(College of Grassland Agriculture,Northwest A&F University,Yangling,Shaanxi 712100,China;The Research Center for Soil and Water Conservation and Ecological Environment,Chinese Academy of Sciences and Ministry of Education,Yangling,Shaanxi 712100,China;Institute of Soil and Water Conservation,Chinese Academy of Sciences and ministry of Water Resources,Yangling,Shaanxi 712100,China;University of Chinese Academy of Sciences,Beijing 100049,China;College of Soil and Water Conservation Science and Engineering,Northwest A&F University,Yangling,Shaanxi 712100,China)

机构地区：[1]西北农林科技大学草业与草原学院,陕西杨凌712100 [2]中国科学院教育部水土保持与生态环境研究中心,陕西杨凌712100 [3]中国科学院水利部水土保持研究所,陕西杨凌712100 [4]中国科学院大学,北京100049 [5]西北农林科技大学水土保持科学与工程学院,陕西杨凌712100

出　　处：《水土保持通报》2024年第5期243-250,261,共9页Bulletin of Soil and Water Conservation

基　　金：国家自然科学基金项目“灌丛化和降水变化对半干旱草原土壤磷组分转化的影响及调控机制”(42377471);2023年中央财政林业草原生态保护恢复资金项目“云雾山国家级自然保护区补助采购项目二标段”(D6400000141010004-2)。

摘　　要：[目的]探究黄土高原封育草地土壤养分及微生物养分需求变化对草地灌丛化的响应特征,为黄土高原封育草地资源管理提供科学参考。[方法]选取云雾山国家级自然保护区未灌丛化草地、半灌木白莲蒿(Artemisia sacrorum)扩张草地和灌木矮脚锦鸡儿(Caragana brachypoda)扩张草地为研究对象,测定不同样地土壤理化性质及参与土壤碳、氮、磷循环的5种酶活性,分析草地灌丛化对土壤养分、酶活性及化学计量比的影响。[结果]草地灌丛化提高了土壤水分、养分含量及碳、氮、磷循环酶活性,但是不同土层土壤微生物养分需求并不一致。在0-15 cm土层中灌丛化草地土壤微生物对磷元素需求更高,而在15-30 cm土层中灌丛化草地土壤微生物对碳元素需求更高。冗余分析结果表明,土壤中养分有效性是影响土壤酶活性及化学计量比变化的关键因子。[结论]鉴于黄土高原封育草地灌丛化对土壤养分含量及酶活性的正效应,且灌丛下土壤微生物会通过改变碳、氮、磷循环酶相对投入以满足其养分需求,因此,未来该地区半灌木和灌木扩张趋势会进一步加强,亟待探索相应的调控措施以维持黄土高原草地生态系统稳定性。[Objective]The response characteristics and demand changes of soil and microbial nutrients to shrub encroachment in Loess Plateau were investigated to provide reference for grassland resource management in the Loess Plateau.[Methods]The no-shrub encroachment grassland,subshrub(Artemisia sacrorum)encroachment grassland,and shrub(Caragana brachypoda)encroachment grassland in the Yunwu Mountain National Nature Reserve and measured the physicochemical properties of soil and activities of five enzymes involved in soil carbon,nitrogen,and phosphorus cycles.Afterward,we analyzed the effects of subshrub and shrub encroachment on soil nutrient content,enzyme activities,and stoichiometric ratios.[Results]Subshrub and shrub encroachment increased the content of soil water and nutrients and the activities of carbon,nitrogen,and phosphorus cycling enzymes.Soil microbial nutrient demands were not consistent across soil layers:in the 0-15 cm soil layer,soil microorganisms in the subshrub and shrub encroachment grassland had a higher demand for phosphorus element,whereas in the 15-30 cm soil layer,soil microorganisms had a higher demand for carbon element.Redundancy analysis showed that soil available nutrients were the key factors affecting soil enzyme activity and stoichiometric ratio.[Conclusion]Subshrub and shrub encroachment had positive effects on soil nutrient content and enzyme activity of enclosed grassland in Loess Plateau,and soil microorganisms under the subshrub and shrub encroachment grassland met their nutrient demands by changing the relative input of carbon,nitrogen,and phosphorus cycling enzymes;therefore,the trend of subshrub and shrub expansion in the region need to be further strengthened in the future.To maintain the stability of grassland ecosystem in Loess Plateau,corresponding regulatory measures need to be explored urgently.

关 键 词：黄土高原 封育草地 灌丛化 养分 酶化学计量 

分 类 号：S812.2[农业科学—草业科学] S154.1[农业科学—畜牧学]