矮嵩草草甸主要植物不同器官对氮素的吸收及分配特征研究.pdfVIP

矮嵩草草甸主要植物不同器官对氮素的吸收及分配特征研究 徐隆华;姚步青;王文颖;马真;石国玺;周华坤 【摘要】Using 15N tracer technique,we quantify the characteristics of nitrogen absorption and distribution by organs of seven plant species in the Kobresia humilis alpine meadow,in order to reveal the ecological adaptability,competitiveness and position in the community of the main plants.The results showed:(1) the leaf and stem of K.humilis,the leaf of Elymus nutans,the leaf and stem and root of Scirpus distigmaticus and Pedicularis kansuensis can effectively accumulate nitrate nitrogen.The ear and leaf of Poaannua,the root of P.kansuensis and Lagotis brachystachya Maxim can effectively accumulate ammonium nitrogen.(2) Glycine and nitrate nitrogen absorbed by K.humilis mainly allocated in leaf and ammonium nitrogen allocated in stem.Glycine and nitrate nitrogen absorbed by S.distigmaticus mainly allocated in stem,ammonium nitrogen allocated in leaf.Inorganic nitrogen absorbed by E.nutans and P.annua allocated mainly in leaf.The glycine absorbed by E.nutans mainly allocated in root and by P.annua allocated in ear.Nitrate nitrogen mainly allocated in leaf and ammonium nitrogen allocated in root absorbed by P.kansuensis.The glycine and inorganic nitrogen absorbed by P.anserina mainly allocated in leaf.Glycine absorbed by L.brachystachya mainly allocated in leaf,while nitrate nitrogen and ammonium nitrogen mainly allocated in root.(3) Organic nitrogen and inorganic nitrogen in soil of K.humilis meadow mainly contributed to the flower of P.kansuensis,the ear of P.annua,the root of E.nutans and shoot of P.anserina at herbage growth stage.Absorption and distribution of nitrogen has diversified characteristics in different organs of the main plants in K.humilis meadow,that differed in the biological characteristics and ecological habits of different plant species.%以高寒矮嵩草(Kobresia humilis)草甸 7 个主要植物 种为研究对象,利用 15N 同位素标记技术,通过分析不同器官对氮素的吸收及分配特 征,揭示主要植物种在群落中的生态适应性、竞争力和地位.结果显示:(1)矮嵩草的叶 和茎、垂穗披碱草(El ymus