欢迎访问《应用生态学报》官方网站,今天是 分享到:

应用生态学报 ›› 2020, Vol. 31 ›› Issue (6): 2067-2075.doi: 10.13287/j.1001-9332.202006.031

• 研究报告 • 上一篇    下一篇

新疆开都河大型水生植物的氮磷化学计量特征及其影响因素

彭庆文1,2,3, 严正兵4, 罗艳1,2,3, 李凯辉1,2,5, 韩文轩1,5*   

  1. 1中国科学院新疆生态与地理研究所干旱区生物地理与生物资源重点实验室, 乌鲁木齐 830011;
    2中国科学院巴音布鲁克草原生态系统研究站, 新疆巴音郭楞 841314;
    3中国科学院大学, 北京 100049;
    4香港大学生物科学学院, 香港 999077;
    5中国科学院中亚生态与环境研究中心, 乌鲁木齐 830011
  • 收稿日期:2019-11-01 出版日期:2020-06-15 发布日期:2020-06-15
  • 通讯作者: * E-mail: hanwenxuan@ms.xjb.ac.cn
  • 作者简介:彭庆文, 男, 1994年生, 硕士研究生。主要从事生态化学计量学研究。E-mail: pengqingwen17@mails.ucas.ac.cn
  • 基金资助:
    新疆维吾尔自治区高端人才引进计划项目和中国科学院“西部之光”项目资助

Nitrogen and phosphorus stoichiometry of aquatic macrophytes in Kaidu River of Xinjiang and the potential influencing factors

PENG Qing-wen1,2,3, YAN Zheng-bing4, LUO Yan1,2,3, LI Kai-hui1,2,5, HAN Wen-xuan1,5*   

  1. 1Key Laboratory of Biogeography and Bioresource in Arid Land, Xinjiang Institute of Ecology and Geography, Chinese Academy of Sciences, Urumqi 830011, China;
    2Bayanbulak Grassland Ecosystem Research Station, Chinese Academy of Sciences, Bayingol 841314, Xinjiang, China;
    3University of Chinese Academy of Sciences, Beijing 100049, China;
    4School of Biological Sciences, University of Hong Kong, Hong Kong 999077, China;
    5Research Center for Ecology and Environment of Central Asia, China Academy of Sciences, Urumqi 830011, China
  • Received:2019-11-01 Online:2020-06-15 Published:2020-06-15
  • Contact: * E-mail: hanwenxuan@ms.xjb.ac.cn
  • Supported by:
    This work was supported by the Special Project of Introducing High-level Talents to Xinjiang Uygur Autonomous Region and the Light of West China Program of the Chinese Academy of Sciences.

摘要: 氮 (N)、磷(P)是最常见的限制植物生长的矿质元素。水生植物所需营养主要来源于水体和沉积物,植物体内的元素组成能够反映淡水生态系统的营养供应状况。开都河是新疆一条流经高山草甸和荒漠绿洲的重要内陆河。本研究采集了开都河大型水生植物和水、沉积物样品,分析了不同生活型和发育史的植物物种叶的氮磷化学计量特征,探讨了上下游、不同土地利用类型下植物、水体和沉积物化学计量特征的差异和关联。结果表明: 植物叶的N、P平均含量分别为24.9 mg·g-1和2.49 mg·g-1,氮磷质量比值(N/P)平均为12.6。不同生活型植物叶的N、P含量及N/P存在显著差异:沉水植物N、P含量均显著高于浮叶和挺水植物;浮叶植物N/P为19.2,显著高于其他两类植物,表明其生长可能受P的限制。上游水生植物叶的N、P含量均高于下游。同时,河流上游的沉积物和水体中的N含量均高于下游。与农耕区河段相比,草地区河段水生植物的叶N和P含量较高,可能与草地土壤有机质丰富和放牧产生的排泄物有关,说明放牧对开都河水生态系统化学计量特征的影响大于农耕。过度放牧可能使开都河上游水质变差,改变水生态系统的氮磷养分平衡,并最终影响特定区域的生物地球化学循环过程。

Abstract: Nitrogen (N) and phosphorus (P) are two common mineral elements constraining plant growth. Nutrients in aquatic macrophytes are mainly absorbed from water and sediments, and thus elemental composition in plant tissues can reflect the nutritional status in freshwater ecosystems. Kaidu River is an important river flowing through the alpine meadows, deserts, and desert oases in Xinjiang. Herein, samples of aquatic macrophytes, water, and sediments across the Kaidu River were collected. Foliar stoichiometric characteristics of N and P in plants were examined among life forms and phylogeny. The differences and correlations among the stoichiometric characteristics of plants, water bodies, and sediments in the upstream and downstream and across different land use types were elaborated. Results showed that the means of leaf N and P concentrations and N/P mass ratio were 24.9 mg·g-1, 2.49 mg·g-1, and 12.6, respectively. There were significant differences in the leaf N and P stoichiometry among various life forms. Specifically, leaf N and P concentrations in submerged species were significantly higher than that in floating-leaved species and emergent species. The N/P of floating-leaved species was 19.2 and significantly higher than that in other two life-forms, indicating that their growth might be limited by P. Leaf N and P concentrations were higher in the upstream than in the downstream. Nitrogen contents in water and sediment were the higher in the upstream of the river. Compared with the river reaches in farming areas, the higher N and P concentrations of aquatic macrophytes in the grassland regions might be related to the higher contents of organic matter in grassland soils and of animal slurries from flocks and herds, suggesting that grazing exerted larger impact on the stoichiometric characteristics of the Kaidu River ecosystem. Our findings highlighted that overgrazing might accelerate the deterioration of water quality in the upstream of the Kaidu River, disturb the balance of N and P in the aquatic ecosystem, and potentially influence the biogeochemical cycling.