Recent changes in rainfall patterns alter precipitation partitioning in European beech forest

Abstract Climate change models suggest increasing rain variability in Europe with hypothesized cascading effects on ecosystems. However, model results are inconsistent, coarse and lack empirical data. Here, we used a 6.5-year dataset of gross precipitation, throughfall, and plant litter deposition from a beech forest in central Germany to show how water that reaches the Critical Zone is driven by shifting rainfall characteristics and canopy structure. Rain event duration declined distinctly over the observation period, while rain intensity and event frequency increased. These changes caused the throughfall fraction to decrease by 5.75% per year and spatial throughfall variability to rise exponentially. This study provides empirical evidence that precipitation intensification strongly impacts the spatio-temporal distribution of net precipitation in beech forests. This may progressively decouple hydrological links in Europe’s most dominant forest stands, potentially resulting in changing water and element fluxes, weathering, and soil processes.