Phenology and fruit production are sensitive to climate. Variation of leaf phenology alters canopy duration (an indicator of growing season length), which in turn affects forest ecosystem functioning and tree productivity. However, the influence of canopy duration on tree reproduction is poorly explored. In this study, we investigated if and to what extent the canopy duration influences fruit production in three major European deciduous trees: European beech (Fagus sylvatica) and two temperate oaks (Quercus robur and Quercus petraea). We used a long-term (11 years) monitoring dataset from 50 populations. In addition to the widely reported main effect of previous summer temperature on fruit production in European beech, we detected a nonlinear relationship between current canopy duration and fruit production. For beech, intermediate canopy duration is associated with highest fruit production. In oaks, fruit production was positively correlated with spring temperature and current canopy duration. Total variance explained by our models is 45% and 13%, for beech and oaks, respectively. These results suggest contrasting effects of expected increase in canopy duration on fruit production: nonlinear in European beech and positive linear in oaks.

物候和水果生产对气候敏感。叶片物候的变化会改变冠层的持续时间（生长季节长度的指标），进而影响森林生态系统的功能和树木的生产力。但是，树冠持续时间对树木繁殖的影响很少被探讨。在这项研究中，我们调查了树冠持续时间是否以及在何种程度上影响欧洲三大落叶乔木：欧洲山毛榉（Fagus sylvatica）和两种温带栎木（Quercus robur和Quercus petraea））。我们使用了来自50个人群的长期（11年）监测数据集。除了广泛报道的先前夏季温度对欧洲山毛榉果实产量的主要影响外，我们还发现了当前冠层持续时间与果实产量之间的非线性关系。对于山毛榉，中间冠层持续时间与最高果实产量相关。在橡树中，水果产量与春季温度和当前冠层持续时间呈正相关。我们的模型解释的总差异分别为榉木和橡木的45％和13％。这些结果表明，冠层持续时间预期增加对水果产量的反作用：欧洲山毛榉为非线性，而橡木为正线性。