Li Yirong, Shi Peijian, Niinemets Ülo, Song Yu, Yu Kexin, Schrader Julian, Niklas Karl J
Bamboo Research Institute, Nanjing Forestry University, Nanjing, 210037, China.
Institute of Agricultural and Environmental Sciences, Estonian University of Life Sciences, Tartu, 51006, Estonia.
Am J Bot. 2022 Mar;109(3):377-392. doi: 10.1002/ajb2.1812. Epub 2022 Mar 25.
The phenomenon called "diminishing returns" refers to a scaling relationship between lamina mass (M) vs. lamina area (A) in many species, i.e., M ∝ A , where α is the scaling exponent exceeding unity. Prior studies have focused on the scaling relationships between lamina dry mass (DM) and A, or between fresh mass (FM) and A. However, the scaling between petiole mass and M and A has seldom been investigated. Here, we examine the scaling relationships among FM, DM, A, and petiole fresh mass (PFM).
For each of 3268 leaves from nine Lauraceae species, FM, DM, A, and PFM were measured, and their scaling relationships were fitted using reduced major axis regression protocols. The bootstrap percentile method was used to test the significance of the difference in α-values between any two species.
The phenomenon of diminishing returns was verified between FM vs. A and DM vs. A. The FM vs. A scaling relationship was statistically more robust than the DM vs. A scaling relationship based on bivariate regression r -values. Diminishing returns were also observed for the PFM vs. FM and PFM vs. A scaling relationships. The PFM vs. FM scaling relationship was statistically more robust than the PFM vs. A scaling relationship.
"Diminishing returns" was confirmed among the FM, DM, A, and PFM scaling relationships. The data collectively indicate that the petiole scales mechanically more strongly with lamina mass than with area, suggesting that static (self) loading takes precedence over dynamic (wind) loading.
所谓“收益递减”现象是指许多物种中叶片质量（M）与叶片面积（A）之间的一种比例关系，即M ∝ A ，其中α为超过1的比例指数。先前的研究主要关注叶片干质量（DM）与A之间或鲜质量（FM）与A之间的比例关系。然而，叶柄质量与M和A之间的比例关系很少被研究。在此，我们研究FM、DM、A和叶柄鲜质量（PFM）之间的比例关系。
对9种樟科植物的3268片叶子分别测量FM、DM、A和PFM，并使用主轴回归协议拟合它们的比例关系。采用自助百分位数法检验任意两个物种之间α值差异的显著性。
FM与A以及DM与A之间验证了收益递减现象。基于双变量回归r值，FM与A的比例关系在统计学上比DM与A的比例关系更稳健。PFM与FM以及PFM与A的比例关系也观察到收益递减。PFM与FM的比例关系在统计学上比PFM与A的比例关系更稳健。
在FM、DM、A和PFM的比例关系中证实了“收益递减”。这些数据共同表明，叶柄与叶片质量的机械比例关系比与面积的更强，这表明静态（自身）负载优先于动态（风）负载。
