增温对窄叶鲜卑花高寒灌丛生物量碳和氮分配的影响  

Effects of Warming on Biomass Carbon and Nitrogen Allocation in an Alpine Sibiraea angustata Shrubland

作　　者：刘美[1] 马志良 LIU Mei;MA Zhiliang(Ecological Security and Protection Key Laboratory of Sichuan Province,Mianyang Normal University,Mianyang,Sichuan 621000,China;College of Life Science,China West Normal University,Nanchong,Sichuan 637009,China)

机构地区：[1]绵阳师范学院生态安全与保护四川省重点实验室,四川绵阳621000 [2]西华师范大学生命科学学院,四川南充637009

出　　处：《西北植物学报》2023年第5期814-825,共12页Acta Botanica Boreali-Occidentalia Sinica

基　　金：西华师范大学基本科研业务费项目(19B036);绵阳师范学院科研启动项目(QD2021A37);绵阳师范学院生态安全与保护四川省重点实验室开放项目(ESP2102)。

摘　　要：文章以青藏高原东部窄叶鲜卑花灌丛为研究对象,采用开顶式生长室(OTCs)模拟增温实验(+1.2℃),分析增温对灌木层和草本层各器官碳、氮分配的影响及其影响因素,以揭示青藏高原东部高寒灌丛灌木层和草本层碳、氮分配对增温的响应策略。结果显示:(1)增温使窄叶鲜卑花灌木层叶、粗根、细根碳库显著增加18.8%、7.7%和139.4%,使灌木层细根氮库显著增加153.9%;增温使草本层地上和地下部分碳库显著增加60.4%和130.5%,使草本层地上和地下部分氮库显著增加46.1%和124.0%。(2)增温使灌木层茎和粗根碳分配比例显著降低18.9%和16.2%,使灌木层叶、茎和粗根氮分配比例显著降低25.2%、23.3%和14.4%,使灌木层细根碳、氮分配比例显著增加86.5%和96.2%;增温使草本层地上部分碳、氮分配比例显著降低19.5%和18.9%,使草本层地下部分碳、氮分配比例显著增加15.6%和24.8%。(3)Pearson相关分析和多元线性回归分析结果表明,空气温度和土壤微生物生物量是影响灌木层地上碳、氮分配的主要因子,能解释其变异的72.0%以上;土壤温度、土壤有机碳含量和土壤脲酶活性是影响灌木层地下碳、氮分配的主要因子,能解释其变异的92.0%以上;土壤有机碳含量、土壤转化酶和脲酶活性是影响草本层地上和地下碳、氮分配的主要因子,能解释其变异的92.8%以上。(4)土壤氮素有效性对灌木层和草本层生物量碳、氮分配的影响不显著。研究表明,气候变暖情景下,青藏高原东部窄叶鲜卑花高寒灌丛的灌木层和草本层植物通过提高地下部分碳、氮分配,进而更好地适应外界环境温度的提高。To reveal the response strategy of carbon and nitrogen allocation in shrub and herb layers to warming in the alpine shrublands,in this study,we conducted a simulating warming experiment(+1.2℃)using the open-top chambers to analyze the influences of warming on carbon and nitrogen allocation among the above-and belowground organs of shrubs and herbs in an alpine shrubland dominated by Sibiraea angustata shrubs on the eastern Qinghai-Tibetan Plateau.The results showed that:(1)warming significantly increased the carbon pool of shrub leaf,coarse roots and fine roots of S.angustata by 18.8%,7.7%and 139.4%,respectively,as well as the nitrogen pool of shrub fine roots by 153.9%.Warming significantly increased the carbon pool of the above-and belowground parts of herbs by 60.4%and 130.5%,respectively,as well as the nitrogen pool of the above-and belowground parts of herbs by 46.1%and 124.0%,respectively.(2)Warming significantly decreased the carbon allocation proportions of shrub stem and coarse roots by 18.9%and 16.2%,respectively,and significantly decreased nitrogen allocation proportions of shrub leaf,stem and coarse roots by 25.2%,23.3%and 14.4%,respectively.However,warming significantly increased carbon and nitrogen allocation proportions of shrub fine roots by 86.5%and 96.2%,respectively.While warming decreased the carbon and nitrogen allocation proportions of the aboveground parts of herbs by 19.5%and 18.9%,respectively,but significantly increased the carbon and nitrogen allocation proportions of the belowground parts of herbs by 15.6%and 24.8%,respectively.(3)Pearson correlation analysis and multiple linear regression analysis showed that the air temperature and soil microbial biomass were the main factors influencing the aboveground carbon and nitrogen allocation of shrubs,which could explain more than 72.0%of the variance.While the soil temperature,soil organic carbon and soil urease activity were the main factors influencing the belowground carbon and nitrogen allocation of shrubs,which could explain more tha

关 键 词：增温 植物器官 碳氮分配 灌木层 草本层 高寒灌丛 

分 类 号：Q948.1122[生物学—植物学]