植物生态学报 ›› 2021, Vol. 45 ›› Issue (9): 942-951.DOI: 10.17521/cjpe.2021.0140

• 研究论文 • 上一篇    下一篇

八个树种叶水力性状对水分条件的响应及其驱动因素

任金培, 李俊鹏, 王卫锋, 代永欣, 王林()   

  1. 山西农业大学林学院, 山西太谷 030801
  • 收稿日期:2021-04-14 接受日期:2021-08-09 出版日期:2021-09-20 发布日期:2021-11-18
  • 通讯作者: 王林
  • 作者简介:ORCID: *王林: 0000-0002-1658-4720(lwanger@163.com)
  • 基金资助:
    中央级公益性科研院所基本科研业务资金项目(CAFYBB2017ZX002);山西省应用基础研究项目(201801D121246);山西省重点研发计划(201903D221051)

Responses of leaf hydraulic traits to water conditions in eight tree species and the driving factors

REN Jin-Pei, LI Jun-Peng, WANG Wei-Feng, DAI Yong-Xin, WANG Lin()   

  1. College of Forestry, Shanxi Agricultural University, Taigu, Shanxi 030801, China
  • Received:2021-04-14 Accepted:2021-08-09 Online:2021-09-20 Published:2021-11-18
  • Contact: WANG Lin
  • Supported by:
    Central Public-interest Scientific Institution Basal Research Fund(CAFYBB2017ZX002);Applied Basic Research Project of Shanxi Province(201801D121246);Planting Project for Key Research in Shanxi Province(201903D221051)

摘要:

树木叶片的水力效率和安全性会对水分条件的改变做出一定的响应, 进而影响树木的生长和分布, 然而叶导水率(Kleaf)和叶水力脆弱性(P50)对不同水分条件的响应模式及其影响因素尚不清楚。该研究选取了晋西北关帝山和黑茶山两种水分条件下的8种树种, 测量其水力性状、叶片导管和形态性状, 比较两地不同树种的KleafP50的变化, 分析叶片水力效率和安全性之间的权衡关系, 并探讨叶片水力性状在不同树种及水分条件下的响应模式及其驱动因素。结果表明: 对同一树种而言, 湿润的关帝山叶最大导水率(Kmax)和P50均高于干旱的黑茶山; 对同一地区而言, 从在高水分条件下生长的树种到在易干旱环境生长的树种, KmaxP50均逐渐下降。KmaxP50、膨压丧失点水势(TLP)之间均存在显著相关关系。两地叶片P50与导管密度、导管塌陷预测值((t/b)3)、叶片厚度、比叶质量显著正相关, 与导管直径、叶面积显著负相关, 不同树种的KleafP50与叶导管性状的关系大于叶形态性状。同一树种的关帝山到黑茶山P50变化量(δP50)与比叶质量和叶干物质含量在两地的变化量显著正相关, 同一树种δP50与叶形态性状变化量的关系大于与叶导管性状的。以上结果表明: 随着水分条件变差, 叶片水力效率降低, 水力安全性提高, 不同树种叶片水力效率与安全性之间存在一定的权衡关系, 不同树种叶水力性状的差别受叶导管性状影响的程度大于受叶形态性状的影响, 同一树种叶水力安全性对水分条件变化的响应主要依靠叶形态性状的驱动, 树木在提高自身叶水力安全的同时增加了叶构建的碳投资。

关键词: 水力性状, 导管性状, 形态性状, 叶导水率, 叶水力脆弱性

Abstract:

Aims The hydraulic efficiency and safety of tree leaves can respond to changes in water conditions, hence affecting the growth and distribution of trees. This study was conducted to determine the patterns of responses in leaf hydraulic conductivity (Kleaf) and leaf hydraulic vulnerability (P50) in trees to varying water conditions and the influencing factors.

Methods In this study, eight tree species were selected at the study sites of Guandi Mountain and Heicha Mountain in northwestern Shanxi, and their hydraulic traits, leaf vessel and morphological traits were measured. Changes of Kleaf and P50 in those eight tree species were compared between the two locations. The trade-off relationship between leaf hydraulic efficiency and safety was analyzed.

Important findings Within the same tree species, the maximum hydraulic conductivity (Kmax) and P50 were higher at the moist Guandi Mountain sites than at the dry Heicha Mountain sites; within the same study areas, Kmax and P50 were higher in tree species occurring under high water availability than those in drought-prone environment. There were significant correlations among Kmax, P50 and water potential at turgor loss points (TLP). Leaf P50 in trees in the two study areas was significantly and positively correlated with the number of vessels per unit area, the predicted value of vessel collapse ((t/b)3), leaf thickness, and leaf mass per unit area, and negatively with vessel diameter and leaf area. Kleaf and P50 in different tree species were better related with leaf vessel traits than with leaf morphological traits. The changes in P50(δP50) from Guandi Mountain to Heicha Mountain within the same tree species were significantly and positively correlated with changes in leaf mass per unit area and leaf dry mass content, and δP50 was more closely related with the leaf morphological traits than with the leaf vessel traits within the same tree species. The above results indicate that, with deterioration of water conditions, leaf hydraulic efficiency decreases while the hydraulic safety increases. There is a certain trade-off between leaf hydraulic efficiency and safety across different tree species. The differences in leaf hydraulic traits among tree species are more affected by leaf vessel traits than leaf morphological traits. The responses of leaf hydraulic safety to changes in water conditions are mainly driven by leaf morphological traits. An improvement in leaf hydraulic safety occurs at the expenses of structural carbon investment.

Key words: hydraulic trait, vessel trait, morphological trait, leaf hydraulic conductivity, leaf hydraulic vulnerability