新疆天山北坡是我国西北干旱区重要的农业生产基地,近年来受到气候变化和水肥管理措施影响强烈。该地区气候整体上呈现出“暖湿化”的特征,同时水肥管理措施不断优化,使得农田生态系统生产力发生明显变化。在此背景下,深入揭示气候变化...新疆天山北坡是我国西北干旱区重要的农业生产基地,近年来受到气候变化和水肥管理措施影响强烈。该地区气候整体上呈现出“暖湿化”的特征,同时水肥管理措施不断优化,使得农田生态系统生产力发生明显变化。在此背景下,深入揭示气候变化与水肥管理措施对农田生态系统的耦合作用机制,并确定科学的水肥管理措施以适应气候变化给干旱区农田带来的影响,对保障区域粮食安全与发挥农业大国的优势具有重要意义。基于Biome-BGC MuSo模型,将天山北坡主要农作物生理生态参数、管理模块参数本地化,揭示1979—2018年天山北坡农田生态系统NPP的时空分布特征,量化气候变化与水肥管理措施对NPP的相对贡献,探究NPP对不同灌溉、施肥措施的响应。结果表明:(1)1979—2018年天山北坡农田生态系统NPP以2011年为分界点先增后减,多年平均值为0.409 kg C m^(-2)a^(-1)。NPP高值区主要位于奇台县南部以及温泉县等,以玉米、小麦种植为主;低值区较为分散,在乌苏市北部、沙湾县、玛纳斯县等均有分布,以棉花种植为主。(2)气候变化和管理措施对天山北坡农田生态系统NPP的相对贡献率分别为38.75%、61.25%,并且科学的管理措施能够有效放大气候变化对NPP的正向作用、缓解气候变化的负面影响。(3)玉米、小麦、棉花NPP随灌溉量和施肥量的增加先上升后趋于不变,灌溉量475 mm和施肥量236 kg/hm^(2)(基准量的1.3倍)构成水肥管理最优组合,超出此阈值农作物NPP增幅明显减弱。研究结果可为干旱区农田生态系统应对气候变化、维持区域可持续发展提供理论参考。展开更多
Agricultural ecosystems play a pivotal role in global carbon(C)sequestration efforts.Microbial C use efficiency(CUE)serves as a comprehensive metric that reflects the balance between microbial contributions to the acc...Agricultural ecosystems play a pivotal role in global carbon(C)sequestration efforts.Microbial C use efficiency(CUE)serves as a comprehensive metric that reflects the balance between microbial contributions to the accumulation and decomposition of soil organic C.However,the overall distribution patterns and underlying drivers of microbial CUE at the national scale remain unclear.Herein,data from 209 paired samples from 55 studies were analyzed to assess the distribution patterns and influencing factors of microbial CUE based on enzyme stoichiometry(CUE_(ST))in agricultural ecosystems across China.Results revealed that farmlands exhibited the highest CUE_(ST)value(mean=0.51),exceeding those of grasslands(0.46)and forests(0.44).Contrasting patterns of CUE_(ST)regulation were observed across land-use types,with farmlands showing significant(P<0.001)positive relationships of CUE_(ST)with phosphorus vs.nitrogen(N/P)limitation index,while grasslands and forests demonstrated inverse(P<0.05)relationships of CUE_(ST)with C limitation index.Nutrient stoichiometry emerged as the dominant driver of CUE_(ST),with enzyme ratios and mean annual precipitation playing secondary roles.Moreover,land management practices,including fertilization,grazing,and tillage,as well as land-use transition,significantly influenced microbial CUE_(ST)by potentially altering nutrient availability and soil properties;notably,water addition in grasslands had particularly positive effects.These findings provide a critical foundation for harnessing microbial CUE in agriculture and may inform scalable strategies to enhance soil C sequestration and climate-smart land management.展开更多
文摘新疆天山北坡是我国西北干旱区重要的农业生产基地,近年来受到气候变化和水肥管理措施影响强烈。该地区气候整体上呈现出“暖湿化”的特征,同时水肥管理措施不断优化,使得农田生态系统生产力发生明显变化。在此背景下,深入揭示气候变化与水肥管理措施对农田生态系统的耦合作用机制,并确定科学的水肥管理措施以适应气候变化给干旱区农田带来的影响,对保障区域粮食安全与发挥农业大国的优势具有重要意义。基于Biome-BGC MuSo模型,将天山北坡主要农作物生理生态参数、管理模块参数本地化,揭示1979—2018年天山北坡农田生态系统NPP的时空分布特征,量化气候变化与水肥管理措施对NPP的相对贡献,探究NPP对不同灌溉、施肥措施的响应。结果表明:(1)1979—2018年天山北坡农田生态系统NPP以2011年为分界点先增后减,多年平均值为0.409 kg C m^(-2)a^(-1)。NPP高值区主要位于奇台县南部以及温泉县等,以玉米、小麦种植为主;低值区较为分散,在乌苏市北部、沙湾县、玛纳斯县等均有分布,以棉花种植为主。(2)气候变化和管理措施对天山北坡农田生态系统NPP的相对贡献率分别为38.75%、61.25%,并且科学的管理措施能够有效放大气候变化对NPP的正向作用、缓解气候变化的负面影响。(3)玉米、小麦、棉花NPP随灌溉量和施肥量的增加先上升后趋于不变,灌溉量475 mm和施肥量236 kg/hm^(2)(基准量的1.3倍)构成水肥管理最优组合,超出此阈值农作物NPP增幅明显减弱。研究结果可为干旱区农田生态系统应对气候变化、维持区域可持续发展提供理论参考。
基金financially supported by the National Natural Science Foundation of China(Nos.42225706,42377297,42407408,42177283)the Fundamental Research Funds for the Central Universities of China(No.2662023PY010)the support from the Postdoctoral Fellowship Program of the China Postdoctoral Science Foundation(No.GZB20230246)。
文摘Agricultural ecosystems play a pivotal role in global carbon(C)sequestration efforts.Microbial C use efficiency(CUE)serves as a comprehensive metric that reflects the balance between microbial contributions to the accumulation and decomposition of soil organic C.However,the overall distribution patterns and underlying drivers of microbial CUE at the national scale remain unclear.Herein,data from 209 paired samples from 55 studies were analyzed to assess the distribution patterns and influencing factors of microbial CUE based on enzyme stoichiometry(CUE_(ST))in agricultural ecosystems across China.Results revealed that farmlands exhibited the highest CUE_(ST)value(mean=0.51),exceeding those of grasslands(0.46)and forests(0.44).Contrasting patterns of CUE_(ST)regulation were observed across land-use types,with farmlands showing significant(P<0.001)positive relationships of CUE_(ST)with phosphorus vs.nitrogen(N/P)limitation index,while grasslands and forests demonstrated inverse(P<0.05)relationships of CUE_(ST)with C limitation index.Nutrient stoichiometry emerged as the dominant driver of CUE_(ST),with enzyme ratios and mean annual precipitation playing secondary roles.Moreover,land management practices,including fertilization,grazing,and tillage,as well as land-use transition,significantly influenced microbial CUE_(ST)by potentially altering nutrient availability and soil properties;notably,water addition in grasslands had particularly positive effects.These findings provide a critical foundation for harnessing microbial CUE in agriculture and may inform scalable strategies to enhance soil C sequestration and climate-smart land management.
