Like many other ecosystems, subtropical forests are suffering more intense and longer droughts with the ongoing climate change. This study aimed to explore the seasonal transpiration and physiological responses of two dominant tree species, Schima superba and Michelia macclurei, to manipulated precipitation patterns in a subtropical evergreen forest of South China, in which an ambient control treatment (BC), a drier dry and wetter wet season treatment (DD) and an extended dry and wetter wet season treatment (ED) were applied. Tree water use and associated ecophysiological characters, such as the daily whole‐tree transpiration (E_L), intrinsic water use efficiency (WUE_i), Huber values (A_s:A_l) and utilization proportions from different water sources were determined during the period from October 2012 to September 2013. For both tree species, no significant difference in transpiration among the three treatments was observed in the wet season, and a relatively stronger decrease of transpiration occurred under DD and ED treatments during the later dry season. Moreover, the higher transpiration of M. macclurei and its advantage of utilizing the shallow water derived from light rainfall under dry condition suggested that it has more survival and growth advantages in this subtropical forest. Therefore, under the seasonal drought caused by uneven distribution of rainfall in the future, M. macclurei that inclines to use shallow soil water would adopt a drought‐avoidance strategy, whereas S. superba that could uptake deeper soil water would be drought tolerant. The different spatial and temporal patterns of water use, together with the contrasting water use strategies, could reduce competition of the two species and facilitate their coexistence under potential precipitation distribution changes.

中文翻译：

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低亚热带次生常绿森林中两种先驱优势树种在控制降雨条件下的种间蒸腾和水分利用模式

像许多其他生态系统一样，随着气候变化，亚热带森林正遭受更严重和更长时间的干旱。这项研究旨在探讨华南亚热带常绿森林中的两个主要树种（Schima superba和Michelia macclurei）的季节性蒸腾和生理响应对受控降雨模式的影响，其中环境控制处理（BC），干燥和干燥进行了湿润湿季处理（DD）和延长的干湿润湿季处理（ED）。树木用水和相关的生态生理特征，例如每天的整棵树蒸腾量（E _L），内在水分利用效率（WUE _i），胡贝尔值（A_s：A _l）和2012年10月至2013年9月期间来自不同水源的利用比例。对于这两种树种，在雨季，三种处理之间的蒸腾作用没有显着差异，并且下降幅度较大。在干季后期，在DD和ED处理下蒸腾发生。此外，M。macclurei的蒸腾作用较高，其在干旱条件下利用少量降雨产生的浅水的优势表明，它在该亚热带森林中具有更多的生存和生长优势。因此，在未来降雨分布不均引起的季节性干旱下，M。macclurei倾向于使用浅层土壤水将采取干旱避免策略，而能够吸收深层土壤水的超级链球菌则是耐旱的。在潜在的降水分布变化下，不同的水利用时空格局以及不同的用水战略可以减少这两种物种的竞争并促进它们的共存。