植物生态学报 ›› 2023, Vol. 47 ›› Issue (8): 1071-1081.DOI: 10.17521/cjpe.2022.0097

• 研究论文 • 上一篇    下一篇

土壤养分对青藏高原高寒草地生物量响应增温的调节作用

赵艳超1,2, 陈立同1,*()   

  1. 1中国科学院西北高原生物研究所, 西宁 810008
    2中国科学院大学, 北京 100049
  • 收稿日期:2022-03-17 接受日期:2022-07-06 出版日期:2023-08-20 发布日期:2022-09-06
  • 通讯作者: *ORCID: 陈立同: 0000-0002-9797-296X,(litong_chen@nwipb.cas.cn)
  • 基金资助:
    青海省应用基础研究项目(2020-XJ-751)

Soil nutrients modulate response of aboveground biomass to warming in alpine grassland on the Qingzang Plateau

ZHAO Yan-Chao1,2, CHEN Li-Tong1,*()   

  1. 1Northwest Institute of Plateau Biology, Chinese Academy of Sciences, Xining 810008, China
    2University of Chinese Academy of Sciences, Beijing 100049, China
  • Received:2022-03-17 Accepted:2022-07-06 Online:2023-08-20 Published:2022-09-06
  • Contact: *CHEN Li-Tong(litong_chen@nwipb.cas.cn)
  • Supported by:
    Applied Basic Research Project in Qinghai Province(2020-XJ-751)

摘要:

近40年来, 青藏高原经历了快速的增温, 而且预计在将来的几十年里其温度会持续上升。由于气候变暖可能引起土壤水分、养分可利用性的变化, 了解该变化是否会影响高寒草地对气候变暖的响应, 是准确预测未来气候变暖背景下高寒草地生产力变化的重要前提。基于高(4 050 m)、中(3 700 m)、低(3 200 m) 3个海拔的开顶式增温箱(OTCs)增温与施肥(氮(N)肥、磷(P)肥)野外控制实验, 该研究测定了高寒草地群落及其4种功能群(豆科、禾草、莎草、杂类草)的地上绝对和相对生物量, 探讨了高寒草地地上生物量对气候变暖的响应以及土壤养分的调节作用。结果表明: 1)增温处理的响应比与海拔之间存在显著的正相关关系。2)增温导致中、高海拔草地地上生物量的增加, 而且在N、P添加下, 增温均显著增加了3个海拔草地地上生物量。3)不同海拔的4种功能群相对生物量对增温的响应不一致, 而且同一功能群因不同的养分条件对增温表现出了显著的差异。研究表明, 高寒植物对增温的响应依赖于海拔, 并且受到土壤养分可利用性的调节。

关键词: 地上生物量, 高寒草地, 功能群, 增温, 氮添加, 磷添加, 海拔, 青藏高原

Abstract:

Aims In the past 40 years, Qingzang Plateau has experienced rapid warming, and its air temperature is projected to continue to rise in the next few decades. Since climate warming may alter soil moisture and nutrient availability, understanding how these changes affect the responses of alpine grasslands to increasing air temperature is therefore crucial to accurately anticipate the shift in vegetation productivity of alpine grassland ecosystems under future warming.

Methods The aboveground biomass of plant communities and four functional groups (legumes, grasses, sedges, and forbs) in alpine grasslands were measured at the field experiments of warming, fertilization (nitrogen, phosphorus) and their interactions across three altitudes (3 200, 3 700 and 4 050 m).

Important findings 1) We found significantly positive correlation of the warming response ratios with altitude. 2) Warming resulted in the increase of aboveground biomass at middle and high elevation; moreover, under the condition of N, P addition, warming significantly increased aboveground biomass at three altitudes. 3) The responses of relative biomass of four functional groups to warming at different altitudes were inconsistent. Even within the same functional group, they showed significant different responses to warming due to the distinct nutrient conditions across the altitudes. Taken together, our results suggest that the responses of alpine grasslands to warming were altitudes-dependent, which was also modulated by soil nutrient availability.

Key words: aboveground biomass, alpine grassland, functional group, warming, nitrogen addition, phosphorus addition, altitude, Qingzang Plateau