Leaf angle distribution influences forest canopy processes like radiation balance, photosynthesis, and evapotranspiration. Indeed, a strong sensitivity to variability in the leaf angle distribution is reported for many models. Difficulties in conducting leaf angle distribution measurements limit data availability and explanations of its species-specific phenology and variation across environmental gradients. This leads to the situation that leaf angle distribution is often the most poorly constrained model parameter. Here, we report a spatial survey of leaf angle distributions and their seasonal and vertical changes for five most abundant forest broadleaf tree species in Europe according to the spatially representative Level I ICP Forests monitoring network. Although we found evidence that leaf angle distribution might be considered a species-specific trait for all studied species except Betula pendula, we advocate the use of leaf angle distributions obtained from actual leaf inclination measurements whenever possible. Data on leaf angle distributions for 50 widespread forest broadleaf tree species in Europe is also reported.

叶角分布影响森林冠层过程，如辐射平衡、光合作用和蒸散。事实上，许多模型都报告了对叶角分布变化的强烈敏感性。进行叶角分布测量的困难限制了数据的可用性和对其物种特异性物候和环境梯度变化的解释。这导致叶角分布通常是约束最差的模型参数的情况。在这里，我们根据具有空间代表性的 I 级 ICP 森林监测网络报告了欧洲五种最丰富的森林阔叶树种的叶角分布及其季节和垂直变化的空间调查。Betula pendula，我们提倡尽可能使用从实际叶倾角测量中获得的叶角分布。还报告了欧洲 50 种广泛分布的森林阔叶树种的叶角分布数据。