Land-cover changes can affect the climate by altering the water and energy balance of the land surface. Numerous modelling studies have indicated that alterations at the land surface can result in considerable changes in precipitation. Yet land-cover-induced precipitation changes remain largely unconstrained by observations. Here we use an observation-based continental-scale statistical model to show that forestation of rain-fed agricultural land in Europe triggers substantial changes in precipitation. Locally, we find an increase in precipitation following forestation, in particular in winter, which is supported by a paired rain-gauge analysis. In addition, forests are estimated to increase downwind precipitation in most regions during summer. By contrast, the downwind effect in winter is positive in coastal areas but near neutral and negative in Continental and Northern Europe, respectively. The combined local and non-local effects of a realistic reforestation scenario, constrained by sustainability safeguards, are estimated to increase summer precipitation by 7.6 ± 6.7% on average over Europe (0.13 ± 0.11 mm d^–1), potentially offsetting a substantial part of the projected precipitation decrease from climate change. We therefore conclude that land-cover-induced alterations of precipitation should be considered when developing land-management strategies for climate change adaptation and mitigation.

土地覆盖变化可以通过改变地表的水和能量平衡来影响气候。大量模拟研究表明，地表的变化会导致降水的显着变化。然而，土地覆盖引起的降水变化在很大程度上仍然不受观测的限制。在这里，我们使用基于观测的大陆尺度统计模型来表明欧洲雨养农业用地的造林会引发降水的显着变化。在当地，我们发现植树造林后降水增加，特别是在冬季，这得到了配对雨量计分析的支持。此外，据估计，夏季大部分地区的森林会增加顺风降水。相比之下，冬季的顺风效应在沿海地区是积极的，但在大陆和北欧分别接近中性和消极。受可持续性保障措施约束的现实重新造林情景的当地和非当地综合影响估计会使欧洲夏季降水量平均增加 7.6 ± 6.7%（0.13 ± 0.11 mm d^–1 )，可能抵消气候变化导致的预计降水量减少的很大一部分。因此，我们得出结论，在制定适应和缓解气候变化的土地管理战略时，应考虑土地覆盖引起的降水变化。