• It is hypothesised that tree distributions in Europe are largely limited by their ability to cope with the summer drought imposed by the Mediterranean climate in the southern areas and by their competitive potential in central regions with more mesic conditions.
• We investigated the extent to which leaf and plant morphology, gas exchange, leaf and stem hydraulics and growth rates have evolved in a coordinated way in oaks (Quercus ) as a result of adaptation to contrasting environmental conditions in this region. We implemented an experiment in which seedlings of 12 European/North African oaks were grown under two watering treatments, a well‐watered treatment and a drought treatment in which plants were subjected to three cycles of drought.
• Consistent with our hypothesis, species from drier summers had traits conferring more tolerance to drought such as small sclerophyllous leaves and lower percent loss of hydraulic conductivity. However, these species did not have lower growth rates as expected by a trade‐off with drought tolerance.
• Overall, our results revealed that climate is an important driver of functional strategies in oaks and that traits have evolved along two coordinated functional axes to adapt to different precipitation and temperature regimes.

中文翻译：

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橡树（栎属）对降水和温度状况的响应，形态，气体交换，生长速率和水力的相关演变。

• 据推测，欧洲树木的分布在很大程度上受到其应对南部地区地中海气候所造成的夏季干旱的能力以及它们在中度条件更为恶劣的中部地区的竞争潜力的限制。
• 我们调查了橡树（栎属）中叶片和植物的形态，气体交换，叶片和茎的水力和生长速率以协调的方式演变的程度，这是由于该地区适应了不同的环境条件所致。我们进行了一项实验，其中12种欧洲/北非橡树的幼苗在两种浇水处理下进行了种植，分别是经过良好浇水处理和干旱处理，其中植物经历了三个干旱周期。
• 与我们的假设一致，夏季较干燥的物种具有赋予更多耐旱性的特征，例如小硬叶状叶片和较低的水力传导率损失。但是，这些物种的生长速度并未达到耐旱性的折衷。
• 总体而言，我们的结果表明，气候是橡树功能策略的重要驱动力，并且性状沿两个协调的功能轴演变以适应不同的降水和温度状况。