The response of European beech (Fagus sylvatica L.) to climate warming will depend on the ability of their populations to adjust tree performance to water shortage. By exploring inter- and intra-annual variations in secondary growth and mean vessel area (MVA), we assessed the effects of precipitation on cambial activity and hydraulic control during the vessel expansion phase along tree lifes. We sampled beech populations at low and high altitude from four mountain ranges across its southwestern distribution edge. We measured a total of 45,897 rings from 126 trees and 5.5 million vessels from 76 trees. We built chronologies for ring width and MVA between 1950 and 2017, calculated their climate responses and evaluated the effects of region, altitude and chronology type (ring-width vs. MVA) by means of ordinations (PCA) and constrained ordinations (pRDA). Precipitation controlled ring width and MVA along beech's southwestern distribution range, but at different time domains. Ring width responded primarily to summer precipitation during the previous growing season, whereas MVA responded to water availability during the vessel expansion phase, with timing shifting along the ring, according to the moment of vessel expansion. Regional differences were significant, but low, compared with the effect of chronology type. A large part of the variance explained by region was due to the strong difference between Western Pyrenees forests –growing under hyperhumid conditions– and the rest of forests under drier and warmer climate. Only minor differences between altitudes were found for the climate control of ring width and vessel size at annual scale, and no intra-annual effect on climate control of MVA. The stronger effect of chronology type on climatic response compared to the role of geographical location or altitude suggests common climate constraints on secondary growth and xylem anatomy along beech dry edge.

欧洲山毛榉（Fagus sylvatica ）的反应L.) 气候变暖将取决于其种群调整树木性能以适应缺水的能力。通过探索次生生长和平均血管面积 (MVA) 的年际和年内变化，我们评估了在血管扩张阶段降水对形成层活动和水力控制的影响。我们从西南分布边缘的四个山脉中采集了低海拔和高海拔的山毛榉种群。我们总共测量了 126 棵树的 45,897 个环和 76 棵树的 550 万条船只。我们建立了 1950 年至 2017 年间环宽和 MVA 的年表，计算了它们的气候响应，并通过排序 (PCA) 和约束排序 (pRDA) 评估了区域、海拔和年表类型（环宽与 MVA）的影响。降水控制了沿山毛榉西南分布范围的环宽和MVA，但在不同的时间域。环宽主要响应前一个生长季节的夏季降水，而 MVA 响应容器扩展阶段的可用水量，根据容器扩展的时刻，时间沿环移动。与年表类型的影响相比，区域差异显着，但较低。按地区解释的很大一部分差异是由于在高湿条件下生长的西部比利牛斯山脉森林与在干燥和温暖气候下生长的其他森林之间的巨大差异。年尺度环宽和船舶尺寸气候控制仅发现海拔高度差异，对MVA气候控制没有年内影响。