As per the abundant-center hypothesis, the cold- and warm-edges of the latitudinal and elevational distributions of vegetation are the result of physiological limitations caused by abiotic stress. The stand-level productivity per leaf mass of plants is an integrated physiological measure of whole-plant carbon gain. The abundant-center hypothesis specifically predicts that the productivity per leaf mass decreases at cold-edges and warm-edges. In the Japanese archipelago, the dominant functional types of trees change from evergreen hardwoods in the south to deciduous hardwoods and evergreen conifers in the north, forming latitudinal ecotones. This study tested the abundant-center hypothesis by analyzing the productivity per leaf mass of each functional type along a gradient of mean annual temperature (MAT), using forest inventory data. Although productivity per leaf mass was variable along the MAT, it neither increased nor decreased with MAT for each functional tree type. The productivity per leaf mass was also noted to not decrease at the cold-edges for evergreen and deciduous hardwoods or at the warm-edges for deciduous hardwoods and evergreen conifers. Productivity per leaf mass was not positively correlated with abundance. Thus, this study did not support the abundant-center hypothesis. Instead, physiological or ecological limitations, particularly at the seedling and sapling stages, may be the important process affecting the distribution edges of these three functional types.

根据丰富中心假说，植被的纬度和海拔分布的冷暖边缘是非生物胁迫引起的生理限制的结果。植物每叶质量的林分生产力是整个植物碳增益的综合生理测量。丰富中心假说特别预测每叶质量的生产力在冷边缘和暖边缘下降。在日本列岛，树木的主要功能类型从南方的常绿阔叶树转变为北方的落叶阔叶树和常绿针叶树，形成纬度交错带。本研究使用森林资源清查数据，通过沿年均温度 (MAT) 梯度分析每种功能类型的每叶质量生产力，检验了丰富中心假设。尽管每个叶质量的生产力沿 MAT 是可变的，但对于每种功能树类型，它既不会随着 MAT 增加也不会减少。还注意到在常绿和落叶阔叶树的冷边缘或落叶阔叶树和常绿针叶树的暖边缘，每叶质量的生产力没有降低。每叶质量的生产力与丰度不呈正相关。因此，本研究不支持丰富中心假设。相反，生理或生态限制，特别是在幼苗和树苗阶段，可能是影响这三种功能类型分布边缘的重要过程。还注意到，在常绿和落叶阔叶树的冷边缘或落叶阔叶树和常绿针叶树的暖边缘，每叶质量的生产力没有降低。每叶质量的生产力与丰度不呈正相关。因此，本研究不支持丰富中心假设。相反，生理或生态限制，特别是在幼苗和树苗阶段，可能是影响这三种功能类型分布边缘的重要过程。还注意到，在常绿和落叶阔叶树的冷边缘或落叶阔叶树和常绿针叶树的暖边缘，每叶质量的生产力没有降低。每叶质量的生产力与丰度不呈正相关。因此，本研究不支持丰富中心假设。相反，生理或生态限制，特别是在幼苗和树苗阶段，可能是影响这三种功能类型分布边缘的重要过程。