Autumn phenology plays a critical role in shaping the carbon sequestration capacity of temperate forests. Notable local-scale variations in autumn phenology have drawn increasing attention recently, potentially introducing substantial uncertainty when predicting temperate forest productivity. Yet the underpinning mechanisms driving these variations remain inadequately elucidated. Here we observed significant and consistent relationships between canopy structure and autumn phenology across six temperate forest sites, induced by the regulation effect of canopy structure on microclimate conditions. Incorporating the identified ‘canopy structure–microclimate–autumn phenology’ pathway into existing autumn phenology models significantly improves the prediction accuracy and reduces the projected delay in the start of autumn over the remainder of the century. These findings offer a new perspective for interpreting the local variations of autumn phenology in temperate forests and emphasize the urgent need to integrate the identified pathway into the Earth system and vegetation models, especially considering the asynchronous changes of macroclimate and microclimate conditions.

秋季物候在塑造温带森林的固碳能力方面起着关键作用。秋季物候的显着局部尺度变化最近引起了越来越多的关注，在预测温带森林生产力时可能带来很大的不确定性。然而，驱动这些变化的基础机制仍未得到充分阐明。在这里，我们观察到 6 个温带森林地点的冠层结构与秋季物候之间存在显著且一致的关系，这是由冠层结构对小气候条件的调节作用诱导的。将已确定的“冠层结构-小气候-秋季物候”途径纳入现有的秋季物候模型，可显著提高预测准确性，并减少本世纪剩余时间内秋季开始的预计延迟。这些发现为解释温带森林秋季物候的局部变化提供了新的视角，并强调了将已确定的途径整合到地球系统和植被模型中的迫切需要，特别是考虑到宏观气候和微气候条件的异步变化。