干旱区研究 ›› 2025, Vol. 42 ›› Issue (7): 1279-1290.doi: 10.13866/j.azr.2025.07.11 cstr: 32277.14.AZR.20250711

• 植物生态 • 上一篇    下一篇

长期氮添加对天山草原植物群落结构和功能的遗留效应

陶欣然1,2,3(), 李海宁3,4, 公延明1,3, 柳妍妍1,3, 刘学军1,5, 李凯辉1,3()   

  1. 1.中国科学院新疆生态与地理研究所,新疆 乌鲁木齐 830011
    2.中国科学院大学,北京 100049
    3.巴音布鲁克高寒草原生态系统新疆野外科学观测研究站,新疆 巴音布鲁克 841314
    4.新疆农业大学草业学院,新疆 乌鲁木齐 830052
    5.中国农业大学资源与环境学院,北京 100193
  • 收稿日期:2024-11-26 修回日期:2025-04-25 出版日期:2025-07-15 发布日期:2025-07-07
  • 通讯作者: 李凯辉. E-mail: likh@ms.xjb.ac.cn
  • 作者简介:陶欣然(2000-),女,硕士研究生,主要从事草地生态系统研究. E-mail: taoxinran22@mails.ucas.ac.cn
  • 基金资助:
    第三次新疆综合科学考察项目(2022xjkk0401)

Legacy effects of long-term nitrogen on plant community structure and function in the Tianshan grassland

TAO Xinran1,2,3(), LI Haining3,4, GONG Yanming1,3, LIU Yanyan1,3, LIU Xuejun1,5, LI Kaihui1,3()   

  1. 1. Xinjiang Institute of Ecology and Geography, Chinese Academy of Sciences, Urumqi 830011, Xinjiang, China
    2. University of the Chinese Academy of Sciences, Beijing 100049, China
    3. Bayinbuluk Alpine Grassland Observation and Research Station of Xinjiang, Bayinbuluk 841314, Xinjiang, China
    4. College of Grassland Science, Xinjiang Agricultural University, Urumqi 830052, Xinjiang, China
    5. College of Resources and Environmental Sciences, China Agricultural University, Beijing 100193, China
  • Received:2024-11-26 Revised:2025-04-25 Published:2025-07-15 Online:2025-07-07

摘要: 在全球大气氮沉降逐渐降低的背景下,长期氮添加对高寒草原生态系统的遗留效应尚不明确。因此,本文通过在天山中部的巴音布鲁克高寒草原开展长达16 a的控制实验,探讨了长期氮添加对草原植物群落的遗留效应。结果表明:(1) 优势物种功能性状方面,停止施肥4 a后,高氮处理(N15,15 g N·m-2·a-1)对天山赖草(Leymus tianschanicus)的植株高度(+20%)、叶面积(+16%)和比叶面积(+5%)仍存在正向遗留效应,对寒生羊茅(Festuca kryloviana)的植株高度(-23%)和比叶面积(-1.5%)仍存在负向遗留效应,且寒生羊茅的遗留效应随恢复时间逐渐减弱。(2) 群落水平上,长期氮添加对根茎型禾草存在正向遗留效应,对丛生型禾草存在负向遗留效应,进而对群落的盖度和地上净初级生产力存在显著的正向遗留效应,且遗留效应表现出逐年减小的趋势。N15水平下,群落盖度的增加幅度由32%降低至18%,群落地上净初级生产力的增加幅度由64%降低至44%。(3) 土壤化学性质方面,氮添加对土壤全氮含量存在显著的正向遗留效应,对土壤全磷和有机碳含量的遗留效应不显著,而土壤pH的负向遗留效应逐年减弱。N15水平下,2024年土壤pH的抑制效应(-1.4%)较2023年(-3.4%)明显缓解。土壤全磷和有机碳含量与植被特征的相关性较低,4种土壤因子对植被变异的综合解释程度较低。本研究表明,在大气氮沉降降低或停止的背景下,历史氮沉降仍对草原生态系统产生持续的遗留效应,且部分指标的遗留效应随恢复时间逐渐减弱。

关键词: 氮沉降, 遗留效应, 响应比, 功能群组成, 叶片功能性状

Abstract:

Against the backdrop of a gradual decline in global atmospheric nitrogen deposition, the legacy effects of long-term nitrogen addition on alpine grassland ecosystems remain unclear. This study investigated such legacy effects on plant communities in alpine grasslands through a 16-year controlled experiment conducted in the Bayinbuluke alpine grassland of the central Tianshan Mountains. The results revealed that: (1) Four years after the end of fertilization and regarding the functional traits of the dominant species, high nitrogen treatment (N15) significantly increased the plant height (+20%), leaf area (+16%), and specific leaf area (+5%) of Leymus tianschanicus but reduced the plant height (-23%) and specific leaf area (-1.5%) of Festuca kryloviana. Moreover, the legacy effects on F. kryloviana gradually weakened over the recovery time. (2) At the community level, long-term nitrogen addition exhibited positive legacy effects on rhizomatous grasses but adverse legacy effects on brunch grasses, significantly enhancing the cover and aboveground net primary productivity of the community. However, these legacy effects exhibited a diminishing trend over time. Under the N15 treatment, the increase in community cover declined from 32% to 18%, while the ANPP decreased from 64% to 44%. (3) Regarding soil chemical properties, adding nitrogen had significant positive legacy effects on the total soil nitrogen content but no significant legacy effects on the total soil phosphorus or organic carbon content. The negative legacy effect on soil pH gradually weakened, with the inhibitory effect under N15 treatment decreasing from -3.4% in 2023 to -1.4% in 2024. Soil total phosphorus and organic carbon content exhibited low correlations with vegetation characteristics, and the four soil factors collectively explained only a small proportion of the vegetation variation. This study demonstrates that, against the background of reduced or ceased atmospheric nitrogen deposition, historical nitrogen deposition continues to exert persistent legacy effects on grassland ecosystems, with some of these effects gradually diminishing over the recovery time.

Key words: nitrogen deposition, legacy effect, response ratio, functional group composition, leaf functional traits