Data from: Morphological and moisture availability controls of the leaf area-to-sapwood area ratio: analysis of measurements on Australian trees

1. The leaf area-to-sapwood area ratio (LA:SA) is a key plant trait that links photosynthesis to transpiration. The pipe model theory states that the sapwood cross-sectional area of a stem or branch at any point should scale isometrically with the area of leaves distal to that point. Optimization theory further suggests that LA:SA should decrease toward drier climates. Although acclimation of LA:SA to climate has been reported within species, much less is known about the scaling of this trait with climate among species. 2. We compiled LA:SA measurements from 184 species of Australian evergreen angiosperm trees. The pipe model was broadly confirmed, based on measurements on branches and trunks of trees from one to 27 years old. Despite considerable scatter in LA:SA among species, quantile regression showed strong (0.2 < R1 < 0.65) positive relationships between two climatic moisture indices and the lowermost (5%) and uppermost (5–15%) quantiles of log LA:SA, suggesting that moisture availability constrains the envelope of minimum and maximum values of LA:SA typical for any given climate. 3. Interspecific differences in plant hydraulic conductivity are probably responsible for the large scatter of values in the mid-quantile range and may be an important determinant of tree morphology.,Supplementary information 1_LA_SA Togashi datasetHuber Value dataset for 183 evergreen angiosperm trees in Australia,

1. 叶面积与边材面积之比（LA:SA）是连接光合作用与蒸腾作用的关键植物性状。管道模型理论（pipe model theory）指出，任意位置处的茎干或枝条的边材横截面积，应与该位置远端的叶片面积呈等轴缩放关系。最优化理论进一步表明，LA:SA值会随气候愈发干旱而降低。尽管已有研究报道了种内LA:SA对气候的驯化响应，但针对跨物种间该性状随气候的缩放规律，目前所知甚少。2. 本研究汇编了184种澳大利亚常绿被子植物树木的LA:SA测量数据。基于对1至27年生树木的枝条与树干的实测结果，管道模型理论得到了广泛验证。尽管不同物种间的LA:SA值离散程度较高，但分位数回归分析显示，两项气候湿度指数与对数转换后的LA:SA的最低（5%）和最高（5%~15%）分位数之间存在显著正相关关系（0.2 < R1 < 0.65），这表明水分可利用性限制了特定气候下典型LA:SA的最小与最大取值范围。3. 种间植物导水率的差异可能是导致LA:SA在中分位数区间内离散度较高的原因，同时也可能是树木形态的重要决定因素。补充信息1：LA:SA 户田（Togashi）数据集——澳大利亚183种常绿被子植物树木的胡伯值（Huber value）数据集