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草业学报 ›› 2020, Vol. 29 ›› Issue (8): 37-45.DOI: 10.11686/cyxb2020093

• 研究论文 • 上一篇    下一篇

氮、磷添加对草地不同冠层植物叶片和根系生态化学计量特征的影响

王洪义1, 2, 丁睿1, 王智慧1, 杨凤军1, *   

  1. 1. 黑龙江八一农垦大学园艺园林学院,黑龙江 大庆163319;
    2. 中国科学院沈阳应用生态研究所额尔古纳森林草原过渡带生态系统研究站, 辽宁 沈阳110016
  • 收稿日期:2020-03-06 修回日期:2020-03-23 出版日期:2020-08-20 发布日期:2020-08-20
  • 通讯作者: *. E-mail:yangfengjun@126.com
  • 作者简介:王洪义(1978-),男,黑龙江巴彦人,副教授,博士。E-mail:why021@163.com
  • 基金资助:
    科技部国家重点研发计划子课题(2016YFC0500602),黑龙江八一农垦大学“三横三纵”支持计划(ZRCQC201909)和黑龙江八一农垦大学学成引进人才科研启动基金(XDB201803)资助

Effects of nitrogen and phosphorus addition on C∶N∶P ecological stoichiometry in leaves and roots of different canopy species in Hulunbuir grassland

WANG Hong-yi1, 2, DING Rui1, WANG Zhi-hui1, YANG Feng-jun1, *   

  1. 1. College of Horticulture and Landscape Architecture, Heilongjiang Bayi Agricultural University, Daqing 163319, China;
    2. Erguna Forest-Steppe Ecotone Research Station, Institute of Applied Ecology, Chinese Academy of Sciences, Shenyang 110016, China
  • Received:2020-03-06 Revised:2020-03-23 Online:2020-08-20 Published:2020-08-20

摘要: 植物碳(C)、氮(N)、磷(P)生态化学计量特征能反映植物与环境间的相互作用关系,是评估植物对环境变化响应的重要依据。已有的相关研究多以地上器官为主,而对地下器官关注相对较少。本研究以呼伦贝尔草地不同冠层的4种植物——羊草、披针叶黄华、达乌里芯芭和星毛委陵菜为对象,分析了氮、磷添加对其叶片和根系C∶N∶P生态化学计量特征的影响。结果表明:氮、磷添加对4种植物叶片和根系C含量没有显著影响。氮添加显著提高了3种非豆科植物叶片和根系N含量(达乌里芯芭叶片接近显著)、降低了其C∶N,而磷添加显著提高了4种植物叶片和根系P含量并显著降低了C∶P。氮、磷添加对4种植物C、N、P及其化学计量比均无显著的交互作用。4种植物中,羊草叶片和根系C∶N和C∶P在所有处理中均最高,较高的养分利用效率可能是其成为建群种的重要原因。依据植物叶片N∶P情况判断,该生态系统属于N限制类型。在植物养分限制判断中,根系N∶P不应作为养分限制判断的依据。上述研究结果说明草地植物地上地下器官对氮、磷添加的响应具有协同性,而且不同冠层的植物C、N、P生态化学计量特征对氮、磷添加的响应具有一致性。

关键词: 氮添加, 磷添加, 呼伦贝尔, 生态化学计量

Abstract: Carbon (C), nitrogen (N), and phosphorus (P) ecological stoichiometry can indicate the interactions between plants and environment, which is an important basis for evaluating the response of plants to environmental changes. At present, most of the studies of ecological stoichiometry are about plants and leaves, the aboveground parts of plants, and few studies have investigated roots. Here we report a three-year nitrogen and phosphorus addition experiment with two nitrogen rates (0, 10 g N·m-2·yr-1) two phosphorus rates (0, 10 g P·m-2·yr-1), and the interaction between the two (N0P0 control, and N+P), a total of four treatments, with each treatment repeated five times. Two canopy upper-layer species (Leymus chinensis and Thermopsis lanceolata) and two understory species (Potentilla acaulis and Cymbaria dahurica) in Hulunbuir grassland were investigated, and the effects of nitrogen and phosphorus addition on C∶N∶P ecological stoichiometric characteristics in leaves and roots were analyzed. It was found that nitrogen and phosphorus addition had no impact on C contents in leaves and roots of the four species. Nitrogen addition significantly increased N contents and decreased C∶N in leaves and roots of the three non-leguminous plants, though the effect on P. acaulis leaves was marginal. Phosphorus addition significantly increased P contents and decreased C∶P in leaves and roots of the four species. Nitrogen and phosphorus addition had no significant interaction effects on C, N, or P contents or stoichiometric ratio. C∶N, and C∶P of L. chinensis was the highest among the four species, and thus, we inferred that higher nutrient utilization efficiency was one of key factors for L. chinensis to become a dominant species and a constructive species. In addition, N was the main limiting factor, judging by the N∶P ratio in plant leaves. Therefore N∶P of leaves and not N∶P of roots should be used as the criterion when determining nutrient limitation. Overall, our study suggested that the above and below-ground organs had a synergistic response to nitrogen and phosphorus addition, and the canopy height of plants had no significant effect on C, N, and P ecological stoichiometric characteristics.

Key words: nitrogen addition, phosphorus addition, Hulunbuir, stoichiometry