养分添加和降水变化对荒漠草原地上和地下生物量稳定性的影响  

Effects of nutrient addition and precipitation changes on the stability of aboveground and belowground biomass in desert grassland

作　　者：尹星元 安慧[1] 邢彬彬 苏诗玉 文志林 郭建超 刘小平 王波 Xingyuan Yin;Hui An;Binbin Xing;Shiyu Su;Zhilin Wen;Jianchao Guo;Xiaoping Liu;Bo Wang(Breeding Base for State Key Laboratory of Land Degradation and Ecological Restoration in Northwestern China,Key Laboratory of Restoration and Reconstruction of Degraded Ecosystems in Northwestern China of Ministry of Education,School of Ecology and Environment,Ningxia University,Yinchuan 750021,China;Grassland Experiment Station of Yanchi,Temperate Grassland Ecosystem Observation and Experiment Station in Agro-Pastoral Ecotone of Ningxia,Yanchi,Ningxia 751506,China;Grassland Station of Ningxia Hui Autonomous Region,Yinchuan 750004,China)

机构地区：[1]宁夏大学生态环境学院,西北土地退化与生态恢复省部共建国家重点实验室培育基地,西北退化生态系统恢复与重建教育部重点实验室,银川750021 [2]盐池县草原实验站,宁夏农牧交错带温性草原生态系统定位观测研究站,宁夏盐池751506 [3]宁夏回族自治区草原工作站,银川750004

出　　处：《生物多样性》2024年第7期14-24,共11页Biodiversity Science

基　　金：宁夏自然科学基金(2022AAC02010,2023AAC03402);宁夏自治区留学回国人员创新创业项目(2022,2023)。

摘　　要：为明确荒漠草原生态系统功能和稳定性对水分和养分资源可利用性改变的响应,阐明荒漠草原生物量稳定性的影响机制及途径,本研究在宁夏荒漠草原开展了为期5年的养分添加和降水变化野外控制试验(2018-2022年),试验包括9个处理:对照(Cont)、N添加(N)、NPK添加(NPK)、减少50%降水(Cont–50%)、增加50%降水(Cont+50%)、N添加+减少50%降水(N–50%)、N添加+增加50%降水(N+50%)、NPK添加+减少50%降水(NPK–50%)和NPK添加+增加50%降水(NPK+50%)。通过测定地上、地下生物量及物种多样性,分析了物种异步性、物种多样性、生物量稳定性及生物量稳定性的影响因素。结果表明:(1)养分添加和降水变化显著影响荒漠草原植物群落生物量,NPK+50%处理增加了地上生物量(156.28%)、地下生物量(51.95%)及总生物量(75.67%),而Cont–50%处理降低了地上生物量(45.59%)、地下生物量(25.09%)及总生物量(31.41%);(2)除NPK+50%处理外,其他处理的地上生物量、地下生物量和总生物量稳定性均显著低于对照处理。NPK+50%处理降低了地上生物量稳定性(31.90%),但增加了地下和总生物量稳定性(33.48%和12.38%);(3)养分添加和降水变化显著影响物种多样性(物种丰富度和Shannon-Wiener多样性指数)和物种异步性,其交互作用对物种异步性有显著影响;(4)降水变化通过降低物种异步性进而降低地上生物量稳定性和总生物量稳定性。地上生物量稳定性对总生物量稳定性无显著的直接效应,而地下生物量稳定性对总生物量稳定性具有显著正效应。综上所述,养分添加和降水变化降低荒漠草原生物量稳定性,物种异步性(互补效应)是荒漠草原生物量稳定性的主要影响机制。在荒漠草原地区地下生物量稳定性对总生物量稳定性的贡献大于地上生物量稳定性,因此,在探究植物群落稳定性对养分添加和降水变化的响应模式及其机制时,不能仅局限于植�Aims:This study aims to clarify the response of desert grassland ecosystem function and stability to changes in water and nutrient resource availability,and to elucidate the mechanisms and pathways influencing biomass stability in desert grassland.Methods:This study conducted a 5-year field control experiment on nutrient addition and precipitation changes in desert grasslands in Ningxia from 2018 to 2022.The experimental treatments included:control(Cont),N addition(N,10 g·m^(-2)·yr^(-1)),NPK addition(NPK,10 g·m^(-2)·yr^(-1) N+10 g·m^(-2)·yr^(-1) P+10 g·m^(-2)·yr^(-1) K),50%reduction in precipitation(Cont–50%),50%increase in precipitation(Cont+50%),N addition+50%reduction in precipitation(N–50%),N addition+50%increase in precipitation(N+50%),NPK addition+50%decrease in precipitation(NPK–50%),and NPK addition+50%increase in precipitation(NPK+50%).The aboveground and belowground biomass,as well as species diversity,were determined.Additionally,species asynchrony,species diversity,biomass stability,and the factors affecting biomass stability were analyzed.Results:The results demonstrated that(1)nutrient addition and precipitation changes significantly impacted the biomass of desert grassland plant communities.The NPK+50%treatment led to a substantial increase in aboveground biomass(156.28%),belowground biomass(51.95%),and total biomass(75.67%).In contrast,the Cont–50%treatment resulted in a significant decrease in aboveground biomass(45.59%),belowground biomass(25.09%),and total biomass(31.41%).(2)Except for the NPK+50%treatment,the stability of plant community biomass in other treatments was notably lower than that in the control treatment.The aboveground biomass stability of the NPK+50%treatment decreased by 31.90%,while the stability of belowground and total biomass increased by 33.48%and 12.38%,respectively.(3)Furthermore,nutrient addition and precipitation changes significantly influenced species diversity(including species richness and the Shannon-Wiener diversity index)and species asynchrony.Th

关 键 词：荒漠草原 养分添加 降水变化 地下生物量稳定性 总生物量稳定性 

分 类 号：S812[农业科学—草业科学]