荒漠草原植被及土壤生态化学计量对降水的响应  

Responses of vegetation and soil ecological stoichiometry to precipitation in desert steppe

作　　者：梁晓谦 李建平[1,2] 张翼 尉剑飞 黄绪梅 LIANG Xiaoqian;LI Jianping;ZHANG Yi;YU Jianfei;HUANG Xumei(College of Agriculture,Ningxia University,Yinchuan 750021,Ningxia,China;Training Base of the State Key Laboratory of Restoration and Reconstruction of Degraded Ecosystems in Northwest China,Yinchuan 750021,Ningxia,China)

机构地区：[1]宁夏大学农学院,宁夏银川750021 [2]西北退化生态系统恢复与重建国家重点实验室培训基地,宁夏银川750021

出　　处：《草业科学》2022年第5期864-875,共12页Pratacultural Science

基　　金：宁夏重点研发计划项目(2020BEG03046);宁夏大学草学一流学科建设项目(NXYLXK2017A01)。

摘　　要：利用遮雨棚技术对宁夏盐池县荒漠草原降水量进行人为调控,分析了不同降水梯度[33%、66%、100%(正常降水)、133%和166%]下植物群落地上部分和地下部分,以及土壤的生态化学计量特征,以探讨不同降水梯度对荒漠草原生态系统化学计量学特征的影响。结果表明:1)植物群落地上部分碳(C)随降水的增加逐渐减少,氮磷比(N꞉P)在正常降水下显著(P<0.05)高于降水量增加的处理;植物群落地下部分C、氮(N)、磷(P)随着降水梯度增大而先减后增,且地下部分C、C꞉N、C꞉P均在66%降水处理下显著(P<0.05)高于其他梯度。2)土壤有机碳(SOC)、全氮(TN)、全磷(TP)随降水量的增加而增加;同一增水梯度下,表层土壤的SOC、TN和TP显著(P<0.05)高于深层土层。3)土壤SOC与植物群落地上部分P含量存在显著负相关(P<0.05),植物群落其他部分和土壤C、N、P无显著相关(P>0.05)。研究结果表明,降水变化可改变植物养分分配,增加土壤养分积累,但降水变化过程下荒漠草原植物与土壤间元素耦合关系整体较弱。Changes in precipitation have an important impact on the element cycle between plants and soil,especially in arid areas.Therefore,to better understand the impact of different precipitation gradients on the stoichiometric characteristics of the desert grassland ecosystem,we considered the desert grassland of Yanchi County in Ningxia as the research object,used rain shelters to manually adjust the rainfall in the study area,and measured the carbon(C),nitrogen(N),and phosphorus(P)contents of the plant community and soil of five different precipitation gradients[33%,66%,100%(Control),133%,and 166%].We analyzed the ecological stoichiometric characteristics of the plant community and soil.The results showed that 1)the C content gradually decreases with an increase in the precipitation gradients.The content of N꞉P of normal rainfall is significantly higher(P<0.05)than the rainfall enhancement treatment in above-ground parts of the plant community,the contents of C,N,and P first decrease then increase with the increase of rainfall gradient in below-ground parts of the plant community,and the contents of C,C꞉N,and C꞉P are significantly higher than the treatment of increasing rainfall under the 66%rain reduction treatment(P<0.05).2)Soil organic carbon(SOC),total nitrogen(TN),and total phosphorus(TP)increase with the increase of rainfall.The SOC,TN,and TP of the surface soil are significantly higher than those of the deep soil layer(P<0.05)in the treatment of increasing rainfall.3)There was a significant negative correlation between soil SOC and P contents in the above-ground part of the plant community(P<0.05)but no significant correlation between soil C,N,and P contents in other parts of the plant community.Precipitation changes can change plant nutrient allocation and increase soil nutrient accumulation,but the coupling relationship between plant and soil elements in desert steppe is weak.

关 键 词：降水控制 荒漠草原 生态化学计量 碳 氮 磷 植物地上和地下部分 土壤元素 

分 类 号：S812[农业科学—草业科学]