Journal of Plant Ecology ›› 2023, Vol. 16 ›› Issue (5): 0-rtad009.DOI: 10.1093/jpe/rtad009

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青藏高原高寒草地植物的群落性状和功能在降水梯度上调控了生物量的分配权衡

  

  • 收稿日期:2022-11-24 修回日期:2022-12-18 接受日期:2023-03-01 出版日期:2023-10-01 发布日期:2023-03-09

Plant community traits and functions mediate the biomass trade-off of alpine grasslands along precipitation gradients on the Tibetan Plateau

Le Sun1, Jian Sun1,2,*, Jun-Xi Wu2, Zi-Yin Du3, You-Jun Chen4, Yi Wang5, Miao Liu6, Wen-Cheng Li1, Er-Yuan Liang1   

  1. 1Key Laboratory of Tibetan Plateau Earth System, Environment and Resources, Institute of Tibetan Plateau Research, Chinese Academy of Sciences, Beijing 100101, China;
    2Key Laboratory of Ecosystem Network Observation and Modelling, Institute of Geographic Sciences and Natural Resources Research, Chinese Academy of Sciences, Beijing 100101, China;
    3School of Geographical Sciences, China West Normal University, Nanchong 637002, China;
    4Institute of the Qinghai-Tibetan Plateau, Southwest Minzu University, Chengdu 610500, China;
    5School of Life Sciences and School of Ecology, State Key Lab of Biological Control, Sun Yat-sen University, Guangzhou 510275, China;
    6College of Grassland Science and Technology, China Agricultural University, Beijing 100193, China
  • Received:2022-11-24 Revised:2022-12-18 Accepted:2023-03-01 Online:2023-10-01 Published:2023-03-09
  • Contact: E-mail: sunjian@itpcas.ac.cn

摘要: 了解在不同生态系统中植物生物量分配的调控机制是阐明植物适应性策略的重要理论基础。目前,虽然生境条件对植物生物量分配的影响已被广泛研究,但对植物群落性状和功能(plant community traits and functions, PCTF)如何调控生物量分配,特别是在高寒草地生态系统中的研究却较少。本研究计算了在群落水平上的5种叶片功能性状的群落加权平均值(community-weighted means, CWM),并利用相关分析、方差分解分析和结构方程模型探讨了PCTF与生物量权衡之间的关系。研究结果发现,高寒 草甸(alpine meadow,AM)和高寒草原(alpine steppe, AS)的权衡值都大于零,但两者存在显著差异,AM的权衡值(0.203)明显高于AS (0.088)。此外,决定AS生物量分配的关键因素是物种丰富度(0.69)和叶片干物质含量(CWMLDMC’, 0.42),而在AM中,关键因素是叶片干物质含量(CWMLDMC’, 0.48)和叶片碳含量(CWMLC’, -0.45)。值得注意的是,无论AS中的CWMLDMC和物种丰富度,还是AM中的CWMLDMC和CWMLC都主要受气候因素中的降水调节。总而言之,降水往往通过对PCTF的影响来调控高寒草地的生物量分配,因此强调了PCTF在调节降水梯度上植物生物量分配策略的重要性。

关键词: 群落加权平均, 权衡, 生物量分配, 植物群落性状和功能, 高寒草地, 青藏高原

Abstract: A better understanding the mechanisms driving plant biomass allocation in different ecosystems is an important theoretical basis for illustrating the adaptive strategies of plants. To date, the effects of habitat conditions on plant biomass allocation have been widely studied. However, it is less known how plant community traits and functions (PCTF) affect biomass allocation, particularly in alpine grassland ecosystems. In this study, community-weighted means (CWM) were calculated at the community level using five leaf functional traits, and the relationships between PCTF and biomass trade-offs were explored using correlation analysis, variation partitioning analysis and structural equation modeling. We found that the trade-off values were greater than zero in both alpine meadow (AM) and alpine steppe (AS) across the Tibetan Plateau, with different values of 0.203 and 0.088 for AM and AS, respectively. Moreover, the critical factors determining biomass allocation in AS were species richness (SR; scored at 0.69) and leaf dry matter content of CWM (CWMLDMC’, scored at 0.42), while in AM, the key factors were leaf dry matter content (CWMLDMC’, scored at 0.48) and leaf carbon content of CWM (CWMLC’, scored at -0.45). In particular, both CWMLDMC and SR in AS, as well as CWMLDMC and CWMLC in AM were primarily regulated by precipitation. In summary, precipitation tends to drive biomass allocation in alpine grasslands through its effects on PCTF, hence highlighting the importance of PCTF in regulating plant biomass allocation strategies along precipitation gradients.

Key words: community-weighted means, trade-off, biomass allocation, plant community traits and functions, alpine grasslands, Tibetan Plateau