Whole-tree water transport scales with sapwood capacitance in tropical forest canopy trees
Whole-tree water transport scales with sapwood capacitance in tropical forest canopy trees
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DOI：
10.1046/j.1365-3040.2003.01039.x
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发表时间：
2003-07-01
影响因子：
7.3
通讯作者：
Woodruff, D
中科院分区：
文献类型：
--
作者：
Meinzer, FC;James, SA;Woodruff, D
本研究考察了几种全树水分运输特性与种间边材储水能力差异的关系。研究了边材电容与其他水关系特征之间关系的约束导致固有电容与全树行为之间可预测的标度关系的假设。在热电偶干湿计室内，选取代表木材密度、树木大小、结构和分类多样性范围的4种热带森林冠层树种的边材样品，生成水分释放曲线，并以此计算边材电容的物种特异性值。然后利用边材电容来衡量几种全树的水输送特性，这些特性是通过测量树干上部和基部的液流、分支水势以及作为示踪剂注入树干基部的氘化水（D2O）的轴向和径向运动来确定的。4个树种的边材电容范围为83 ~ 416 kg m(-3) MPa-1，与最小支路水势、土壤-支路水力导度、日储水利用率、D2O轴向和径向运动密切相关。几种全树水分运输特性与边材电容的物种无关尺度表明，与水分运输组织的生物物理特性相关的一个简单变量揭示了植物功能在多个生物组织水平上的实质性收敛。
The present study examines the manner in which several whole-tree water transport properties scale with species-specific variation in sapwood water storage capacity. The hypothesis that constraints on relationships between sapwood capacitance and other water relations characteristics lead to predictable scaling relationships between intrinsic capacitance and whole-tree behaviour was investigated. Samples of sapwood from four tropical forest canopy tree species selected to represent a range of wood density, tree size and architecture, and taxonomic diversity were used to generate moisture release curves in thermocouple psychrometer chambers, from which species-specific values of sapwood capacitance were calculated. Sapwood capacitance was then used to scale several whole-tree water transport properties determined from measurements of upper branch and basal sap flow, branch water potential, and axial and radial movement of deuterated water (D2O) injected into the base of the trunk as a tracer. Sapwood capacitance ranged from 83 to 416 kg m(-3) MPa-1 among the four species studied and was strongly correlated with minimum branch water potential, soil-to-branch hydraulic conductance, daily utilization of stored water, and axial and radial movement of D2O. The species-independent scaling of several whole-tree water transport properties with sapwood capacitance indicated that substantial convergence in plant function at multiple levels of biological organization was revealed by a simple variable related to a biophysical property of water transport tissue.