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不同材性树种的解剖、叶脉分布等结构性状差异会影响树木的水分运输效率和水分利用策略,进而限制树木的生存、生长和分布。然而,材性对叶导水率、水力脆弱性及其潜在的权衡关系的影响尚不清楚。该研究选择东北温带森林中不同材性的9种树种(散孔材:山杨(Populus davidiana)、紫椴(Tilia amurensis)、白桦(Betula platyphylla);环孔材:蒙古栎(Quercus mongolica)、水曲柳(Fraxinus mandshurica)、胡桃楸(Juglans mandshurica);无孔材:红皮云杉(Picea koraiensis)、樟子松(Pinus sylvestris var.mongolica)、红松(Pinus koraiensis),测量其基于叶面积和叶质量的叶导水率(Karea和Kmass)、水力脆弱性(P50)、膨压丧失点水势(TLP)及叶结构性状,以比较不同材性树种叶水力性状的差异,并探索叶水力效率与安全的权衡关系。结果表明:3种材性树种的Karea、Kmass和P50均差异显著(p<0.05)。无孔材树种的Karea和Kmass最低,而散孔材和环孔材树种差异不显著;环孔材树种P50最高,而散孔材和无孔材树种差异不显著。Karea和Kmass均与P50显著负相关(p<0.05),但散孔材、环孔材和无孔材树种的相关关系分别呈线性、幂函数和指数函数关系。这表明叶水力效率与安全之间存在一定的权衡关系,但该关系受树木材性的影响。Kmass与TLP显著负相关(p<0.01),其中散孔材和环孔材树种呈线性负相关,无孔材树种呈负指数函数关系;P50随TLP的增加而增加,这表明树木在面临水分胁迫时,其质外体和共质体抗旱阻力共同协调保护叶片活细胞,防止其水分状况到达临界阈值。Kmass与叶干物质含量、叶密度、比叶重均显著负相关,而P50与之显著正相关(p<0.01,P50与比叶重的关系除外),表明树木叶水力特性的变化受相同叶结构特性驱动,树木增加对水力失调的容忍需要在叶水力系统构建上增加碳投资。
Differences in anatomical and veins distribution of different species of tree species will affect the water transport efficiency and water use strategy of trees, thus limiting the survival, growth and distribution of trees. However, the effect of wood properties on leaf water conductivity, hydraulic fragility and its potential trade-off remains unclear. This study selected nine species of different materials in the temperate forest of northeastern China (Populus davidiana, Tilia amurensis, Betula platyphylla); annulus: Quercus mongolica, Fraxinus mandshurica, Juglans mandshurica; non-porous material: Picea koraiensis, Pinus sylvestris var. Mongolica, Pinus koraiensis, (Karea and Kmass), water stress (P50), turgor loss point water potential (TLP) and leaf structure traits of different species were compared in terms of area and leaf mass, Water efficiency and safety.The results showed that Karea, Kmass and P50 of three wood species were significantly different (p <0.05) .The Karea and Kmass of the non-porous wood species were the lowest, P50 was the highest in annulus, while there was no significant difference between diffuse and non-porous species, Karea and Kmass were negatively correlated with P50 (p <0.05) The relationship between timber species were linear, power function and exponential function. There was a trade-off relationship between leaf water efficiency and safety, but the relationship was affected by the wood properties. Kmass was negatively correlated with TLP (p <0.01) P50 showed a negative exponential function with the increase of TLP, indicating that in the face of water stress, the apoplast and plastid resistance co-ordinate to protect the living cells of the leaves and prevent the water condition from reaching the critical point Threshold value.Kmass was significantly and negatively correlated with leaf dry matter content, leaf density and specific leaf weight, but P50 had a significant positive correlation (p <0.01, P50 and specific leaf weight), indicating that the changes of hydraulic characteristics of trees were affected by the same leaf Structural-driven, increasing tolerance of trees to hydraulic imbalances requires increased carbon investment in the construction of leaf hydraulic systems.