植物生态学报 ›› 2014, Vol. 38 ›› Issue (3): 231-237.DOI: 10.3724/SP.J.1258.2014.00020

所属专题: 生态化学计量 青藏高原植物生态学:生态系统生态学

• • 上一篇    下一篇

氮肥添加对青藏高原高寒草甸6个群落优势种生态化学计量学特征的影响

宾振钧1, 王静静1, 张文鹏1, 徐当会1,*(), 程雪寒1, 李柯杰2, 曹德昊2   

  1. 1兰州大学生命科学学院, 兰州大学草地农业生态系统国家重点实验室, 兰州 730000
    2兰州大学核科学与技术学院, 兰州 730000
  • 收稿日期:2013-10-23 接受日期:2013-12-09 出版日期:2014-10-23 发布日期:2014-02-27
  • 通讯作者: 徐当会
  • 作者简介:*E-mail: dhxu@lzu.edu.cn
  • 基金资助:
    国家自然科学基金(31370423);兰州大学中央高校基本科研业务费专项资金(lzujbky-2013-95);兰州大学中央高校基本科研业务费专项资金(lzujbky-2012-109)

Effects of N addition on ecological stoichiometric characteristics in six dominant plant species of alpine meadow on the Qinghai-Xizang Plateau, China

BIN Zhen-Jun1, WANG Jing-Jing1, ZHANG Wen-Peng1, XU Dang-Hui1,*(), CHENG Xue-Han1, LI Ke-Jie2, CAO De-Hao2   

  1. 1School of Life Science, Lanzhou University / State Key Laboratory of Grassland Agro-ecosystems, Lanzhou University, Lanzhou 730000, China
    2The School of Nuclear Science and Technology, Lanzhou University, Lanzhou 730000, China
  • Received:2013-10-23 Accepted:2013-12-09 Online:2014-10-23 Published:2014-02-27
  • Contact: XU Dang-Hui

摘要:

以青藏高原高寒草甸为研究对象, 通过人工氮肥添加试验, 研究6个群落优势种在不同施氮(N)水平下叶片碳(C)、N、磷(P)元素含量的变化以及生态化学计量学特征。结果表明: 自然条件下, 6个物种叶片N、P质量浓度存在显著的差异, 表现为: 黄花棘豆(Oxytropis ochrocephala)最高, 为24.5和2.51 g·kg-1, 其叶片N含量低于而P含量高于我国其他草地的豆科植物; 其余5个物种叶片N、P质量浓度分别为11.5-18.1和1.49-1.72 g·kg-1, 嵩草(Kobresia myosuroides)叶片N含量最低, 垂穗披碱草(Elymus nutans)叶片P含量最低, 与我国其他区域的研究结果相比, 其叶片N和P含量均低于我国其他草地非豆科植物。随氮素添加量的增大, 6种群落优势种叶片的C和P含量保持不变; 其他5种植物叶片N含量显著增加, 黄花棘豆叶片N含量保持不变。未添加氮肥时, 6种植物叶片N:P为7.3-11.2, 说明该区植物生长更多地受N限制。随N添加量的增加, 除黄花棘豆外, 其他5种植物叶片N:P大于16, 表现为植物生长受P限制。综合研究表明, 青藏草原高寒草甸植物叶片N含量较低, 植物受N影响显著, 但不同物种对N的添加反应不同, 豆科植物黄花棘豆叶片对N添加不敏感, 其他5个物种叶片全N含量随着N添加量的升高而增加, 该研究结果可为高寒草甸科学施肥提供理论依据。

关键词: 高寒草甸, 群落优势种, 生态化学计量学, 氮肥添加, N:P

Abstract:

Aims Our purpose was to characterize the effects of nitrogen (N) addition on plant carbon (C), N, phosphorus (P), and C:N:P ecological stoichiometric characteristics in six dominant plant species, including Kobresia myosuroides, Elymus nutans, Anemone rivularis, Pedicularis kansuensis, Potentilla fragarioides and Oxytropis ochrocephala, of alpine meadow on the Qinghai-Xizang Plateau, China.
Methods N was added at four levels. Concentrations of C, N and P were measured, and C:N:P was estimated in the six plant species following the N addition treatments.
Important findings Significant differences in leaf N and P concentrations existed among the six species under natural conditions. The N and P concentrations were highest in O. ochrocephala, at 24.5 and 2.51 g·kg-1, respectively. The leaf N concentration was significantly lower and leaf P concentration was significantly higher in O. ochrocephala than in legume plants of other grasslands in China. Leaf N and P concentrations in the other five species were in the ranges of 11.5-18.1 and 1.49-1.72 g·kg -1, respectively. Kokresia myosuroides had the lowest N concentrations and E. nutans had the lowest P concentrations; they were significantly lower than the non-legume plants in other grasslands in China (p < 0.001). P and C concentrations did not respond to N addition in all the six plant species, but N concentration significantly increased with N addition in five species other than O. ochrocephala, which did not respond to N addition. Values of the N:P varied in the range of 7.3-11.2 in treatment without N addition, indicating that the plant growth was limited by N in the alpine meadow. Values of the N:P increased and were greater than 16 with N addition in five species other than O. ochrocephala, indicating that N addition induced P deficiency in these five species. Our results point to very low leaf N concentration and limitation of N on plant growth in alpine meadow on the Qinghai-Xizang Plateau, China, but different species had different responses to N addition. The legume plant O. ochrocephala was not susceptible to N addition, but leaf N concentration in other five plant species was increased by N addition. Findings in this study highlight the importance for fertilization and management of alpine meadow.

Key words: alpine meadow, community dominant species, ecological stoichiometry, N addition, N:P