Chin J Plant Ecol ›› 2021, Vol. 45 ›› Issue (9): 942-951.DOI: 10.17521/cjpe.2021.0140

• Research Articles • Previous Articles     Next Articles

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)


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