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### 八个树种叶水力性状对水分条件的响应及其驱动因素

1. 1. 山西农业大学林学院
2. 中国林业科学研究院
• 收稿日期:2021-04-14 修回日期:2021-09-13 发布日期:2021-09-18
• 通讯作者: 王林
• 基金资助:
山西省应用基础研究项目;山西省重点研发计划项目

### Response of leaf hydraulic traits of eight tree species to water conditions and its driving factors

Jin-Pei REN1,Jun-Peng LI1,Wei-Feng WANG1, 2,Lin WANG1

1. 1. College of Forestry, Shanxi Agricultural University
2. Research Institute of New Forestry Technology
• Received:2021-04-14 Revised:2021-09-13 Published:2021-09-18
• Contact: Lin WANG

Abstract: Aims The hydraulic efficiency and safety of tree leaves can respond to the change of water conditions, and hence affect the growth and distribution of trees. However, the response patterns of leaf hydraulic conductivity (Kleaf) and leaf hydraulic vulnerability (P50) to different water conditions and their influencing factors are not clear. Methods In this study, eight same tree species were selected from Guandi Mountain and Heicha Mountain in northwest Shanxi, their hydraulic traits, leaf vessel and morphological traits were measured. The changes of Kleaf and P50 of those tree species in the two places were compared, and the trade-off relationship between leaf hydraulic efficiency and safety was analyzed. The response patterns and driving factors of leaf hydraulic traits of those tree species under different water conditions were discussed. Important findings The results showed that for the same tree species, the maximum hydraulic conductivity (Kmax) and P50 in moist Guandi Mountain were higher than those in dry Heicha Mountain. For the same area, Kmax and P50 decreased gradually from tree species growing in high water conditions to those growing in drought-prone environment.?There was a significant correlation between Kmax, P50 and water potential at turgor loss points (TLP).?Leaf P50 of the two places was significantly positively correlated with 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 correlated with vessel diameter and leaf area.The relationship of Kleaf and P50 of different tree species with leaf vessel traits was greater than that with leaf morphological traits. The P50 variation (δP50) from Guandi Mountain to Heicha Mountain of the same tree species was significantly positively correlated with the variation of leaf mass per unit area and leaf dry mass content in the two places, and the relationship between δP50 of the same tree species and the leaf morphological traits was greater than that of leaf vessel traits.?The above results indicate that with the deterioration of water conditions, leaf hydraulic efficiency decreases and the hydraulic safety increases. There is a certain trade-off between leaf hydraulic efficiency and safety of different tree species. The difference of leaf hydraulic traits of different tree species is more affected by leaf vessel traits than leaf morphological traits. The response of leaf hydraulic safety to the change of water conditions is mainly driven by leaf morphological traits.?Trees not only improve the hydraulic safety of their leaves, but also increase the investment in carbon construction.