温性草甸草原植物碳、氮、磷化学计量与贮量对放牧强度的响应  

Response of carbon,nitrogen and phosphorus stoichiometry and storage of plant to grazing intensity in temperate meadow steppe

作　　者：王淼 张宇 李瑞强 曹娟 辛晓平[1] 朱晓昱 闫瑞瑞[1] WANG Miao;ZHANG Yu;LI Rui-qiang;CAO Juan;XIN Xiao-ping;ZHU Xiao-yu;YAN Rui-rui(Institute of Agricultural Resources and Regional Planning,Chinese Academy of Agricultural Sciences/Hulunbuir Grassland Ecosystem National Field Scientific Observation and Research Station/National Soil Quality Hulunbuir Observation and Experimental Station,Beijing 100081;Inner Mongolia Autonomous Region Environmental Online Monitoring Centre,Hohhot Inner Mongolia 010055;Agro-Environmental Protection Institute of Ministry of Agriculture and Rural Affairs,Tianjin 300191)

机构地区：[1]中国农业科学院农业资源与农业区划研究所/呼伦贝尔草原生态系统国家野外科学观测研究站/国家土壤质量呼伦贝尔观测实验站,北京100081 [2]内蒙古自治区环境在线监控中心,内蒙古呼和浩特010055 [3]农业农村部环境保护科研监测所,天津300191

出　　处：《中国土壤与肥料》2022年第3期201-212,共12页Soil and Fertilizer Sciences in China

基　　金：国家自然基金面上项目(31971769,32101446);国家重点研发计划(2016YFC0500601,2017YFE0104500,2021YFF0703904,2021YFD1300503);中央级公益性科研院所基本科研业务费专项(1610132018009,Y2019YJ13,Y2020YJ19,1610132021016);呼伦贝尔市科技计划项目(YYYFHZ201903,2021hzzx03);财政部和农业农村部:国家现代农业产业技术体系;农业科技创新联盟建设-农业基础性长期性科技工作(NAES037SQ18)。

摘　　要：以呼伦贝尔草甸草原中羊草(Leymus chinensis)、贝加尔针茅(Stipa baicalensis)、寸草苔(Carex duriuscula)、冷蒿(Artemisia frigida)、星毛委陵菜(Potentilla acaulis)和二裂委陵菜(Potentilla bifurca)6种植物为研究对象,研究不同放牧强度对优势植物和退化指示植物碳、氮、磷养分化学计量特征以及贮量的影响。结果表明:(1)随着放牧强度的增加,优势种羊草的碳含量显著减小,退化指示种冷蒿的碳含量显著增加。中度-重度放牧显著增加了6种植物的全氮含量,以及优势种羊草和建群种贝加尔针茅的全磷含量(P<0.05)。(2)随着放牧强度的增加,优势种羊草和建群种贝加尔针茅的碳氮比和碳磷比显著下降,不放牧和轻度放牧显著高于重度放牧(P<0.05);重度放牧降低了物种寸草苔、冷蒿、星毛委陵菜和二裂委陵菜的碳氮比和碳磷比以及寸草苔的氮磷比。(3)放牧使得优势物种羊草的碳、氮、磷贮量显著下降(P<0.05),与不放牧相比,中度-重度放牧碳、氮和磷贮量分别降低了87.10%~98.41%、82.01%~97.55%和82.33%~97.41%;退化指示种冷蒿和星毛委陵菜的碳、氮、磷贮量呈现显著线性增加,适度放牧时,贝加尔针茅和二裂委陵菜的碳、氮、磷贮量最高。(4)羊草、冷蒿、星毛委陵菜和二裂委陵菜在不同放牧强度下,都表现为受氮限制,寸草苔在重度放牧的条件下表现为受氮限制;与重度放牧区相比较,不放牧、轻度放牧以及中度放牧区的贝加尔针茅受磷限制。本研究表明:过度放牧降低优势物种羊草的碳、氮、磷贮量,增加退化指示种冷蒿和星毛委陵菜的碳、氮、磷贮量,适度放牧有利于提高草地植物化学计量平衡与管理水平。Six species,Leymus chinensis,Stipa baicalensis,Carex duriuscula,Artemisia frigida,Potentilla acaulis and Potentilla bifurca in Hulunbuir meadow steppe were used to study the effects of grazing intensity on carbon,nitrogen,phosphorus nutrients,stoichiometry and storage of dominant and degraded plants.The results showed that:(1)With the increase of grazing intensity,the carbon content of the dominant species of L.chinensis decreased significantly,and the carbon content of the degradation indicator species A.frigida increased significantly.Moderate-severe grazing significantly increased the total nitrogen content of six plants,as well as the total phosphorus content of dominant species of L.chinensis and establishment species of S.baicalensis(P<0.05).(2)With the increase of grazing intensity,the carbon-nitrogen ratio and carbon-phosphorus ratio of the dominant species of L.chinensis and the establishment species of S.baicalensis decreased significantly,and the non-grazing and light grazing were significantly higher than those of the heavy grazing(P<0.05);Grazing reduced the carbon-nitrogen ratio and carbon-phosphorus ratio of the species C.duriuscula,A.frigida,P.acaulis and P.bifurca,and the nitrogen-phosphorus ratio of C.duriuscula.(3)Grazing reduced the carbon,nitrogen and phosphorus storages of the dominant species of L.chinensis(P<0.05).Compared with no grazing,the carbon,nitrogen and phosphorus storages of moderate-heavy grazing decreased by 87.10%~98.41%,82.01%~97.55%and 82.33%~97.41%,respectively;The carbon,nitrogen and phosphorus storages of degradation indicator species R.frigida and P.acaulis showed a significant linear increase.Under moderate grazing,the carbon,nitrogen,and phosphorus storages of S.baicalensis and P.bifurca were the highest.(4)L.chinensis,A.frigida,S.baicalensis,and P.bifurca were all restricted by nitrogen under different grazing intensities,while C.duriuscula was restricted by N under heavy grazing condition.Compared with grazing areas,S.baicalensis in non-grazing,light grazing and mode

关 键 词：草甸草原 放牧强度 草地植物 化学计量学 

分 类 号：S812[农业科学—草业科学]