We examined one xylem sampling date (27 July 2021) in the peak growing season in more detail to reveal the discrepancies between seasonal signals and event-scale xylem / precipitation signals for precipitation of the last 12 months prior to xylem sampling (FigureĀ 5). Xylem and bulk soil waters were isotopically similar, whereas most precipitation during the preceding three summer months (yellow boxplots) was isotopically heavier. Thus, the major source of xylem water in the peak growing season of 2021 was a mixture of stored soil waters, so it is important to clarify the relative importance of winter and summer precipitation as sources for soil water storage.