J Plant Ecol ›› Advance articles     DOI:10.1093/jpe/rtaf186

• Research Article •    

Trade-offs between water use efficiency and hydraulic conductivity across 52 woody species distributed in three forests along a precipitation gradient

Mingyang Liu1#, Weiren Wang1#, Qing Ye1, Hui Liu1, Ronghua Li2, Shidan Zhu3, Osazee O. Oyanoghafo4, Pengcheng He1*   

  1. 1Guangdong Provincial Key Laboratory of Applied Botany, Key Laboratory of National Forestry and Grassland Administration on Plant Conservation and Utilization in Southern China, South China Botanical Garden, Chinese Academy of Sciences, Xingke Road 723, Guangzhou 510650, China 

    2Institute of Tropical and Subtropical Ecology, South China Agricultural University, Wushan Road 483, Guangzhou 510642, China 

    3Guangxi Key Laboratory of Forest Ecology and Conservation, College of Forestry, Guangxi University, Nanning 530004, China 

    4Hawkesbury Institute for the Environment, Western Sydney University, Hawkesbury Campus, Bourke Street, Richmond, 2753 NSW Australia 

    #These authors contributed equally to this work. 

    *Corresponding author. E-mail: hepc@scbg.ac.cn

  • Received:2024-11-28 Accepted:2025-09-11 Published:2025-11-12
  • Supported by:
    This work was supported by the National Natural Science Foundation of China (32371641 and 32371575), and Guangdong Science and Technology Plan Project (2023B1212060046).

沿降水梯度分布的三种森林52种木本植物水分利用效率与导水率的权衡关系

Abstract: Water use efficiency and hydraulic conductivity are critical determinants of plant growth and adaptive ability. In principle, high hydraulic conductivity could result in low water use efficiency because of the selection between resource acquisition and resource conservation in species. However, there is insufficient evidence on whether a trade-off exists between these two plant hydraulic traits across species. Here, we quantified eight leaf and branch functional traits associated with water use efficiency and hydraulic conductivity across 52 dominant woody species from three forests (i.e. dry forest, DF; semi-wet forest, SWF; wet forest, WF) along a precipitation gradient in China. We found that plant water use efficiency and hydraulic conductivity were significantly and negatively correlated. Principal component analysis revealed that DF, SWF, and WF species were significantly isolated along axis 1. In contrast to species distributed in WF and SWF, DF species had the lowest hydraulic conductivity, stomatal conductance, and leaf/sapwood area ratio but showed the highest intrinsic water-use efficiency, leaf carbon isotope ratio, and wood density. Stomatal conductance to water explained the differences in plant water use efficiency among different sites, whereas leaf maximum carbon assimilation rate did not. Our results suggest a trade-off between hydraulic conductivity and water use efficiency, which influences the vegetation features in different sites.

Key words: adaptation, carbon assimilation, climate change, distribution, wood density

摘要:
水分利用效率和导水率是决定植物生长与环境适应能力的关键生理性状。理论上,较高的导水率可能导致较低的水分利用效率,反映植物在资源获取型策略与保守型策略之间的权衡。然而,这两种水力性状在跨物种层面上是否存在权衡关系,尚缺乏充分证据。为此,本研究沿降水梯度,选取中国三类森林(干旱森林,dry forest, DF;半湿润森林,semi-wet forest, SWF;湿润森林,wet forest, WF)的52种优势木本植物,测定了水分利用效率和导水率相关的8项叶片和枝条功能性状。研究结果显示,植物水分利用效率与导水率呈显著负相关。主成分分析表明,DF、SWF 和 WF 物种在第一主轴上显著分离。与 WF 和 SWF 物种相比,DF 物种的导水率、气孔导度及总叶面积与边材面积之比较低,但内在水分利用效率、叶片碳同位素比率和木材密度较高。不同生境植物水分利用效率的差异主要受气孔导度调控,而与叶片最大光合速率无关。本研究结果表明,水分利用效率与导水率之间存在权衡关系,且对不同地点的植被特征具有重要影响。

关键词: 环境适应, 碳吸收, 气候变化, 物种分布, 木材密度