植物生态学报

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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

任金培1,李俊鹏1,王卫锋1,代永欣2,王林1   

  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

摘要: 树木叶片的水力效率和安全性会对水分条件的改变作出一定的响应, 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种相同树种, 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Kleaf和P50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, Kmax和P50均逐渐下降。Kmax、P50、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Kleaf和P50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: 随着水分条件的变差, 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程度大于受叶形态性状影响, 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构建碳投资。

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 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.

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