The way species avoid each other in a community by using resources differently across space and time is one of the main drivers of species coexistence in nature1,2. This mechanism, known as niche differentiation, has been widely examined theoretically but still lacks thorough experimental validation in plants. To shape niche differences over time, species within communities can reduce the overlap between their niches or find unexploited environmental space3. Selection and phenotypic plasticity have been advanced as two candidate processes driving niche differentiation4,5, but their respective role remains to be quantified6. Here, we tracked changes in plant height, as a candidate trait for light capture7, in 5-year multispecies sown grasslands. We found increasing among-species height differences over time. Phenotypic plasticity promotes this change, which explains the rapid setting of differentiation in our system. Through the inspection of changes in genetic structure, we also highlighted the contribution of selection. Altogether, we experimentally demonstrated the occurrence of species niche differentiation within artificial grassland communities over a short time scale through the joined action of both plasticity and selection.

中文翻译：

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选择和可塑性都驱动实验草原的生态位分化。

通过在空间和时间上不同地使用资源，物种在社区中彼此避免的方式是自然界中物种共存的主要驱动力之一1,2。这种机制，称为生态位分化，已在理论上进行了广泛研究，但仍缺乏在植物中进行彻底的实验验证。为了随时间变化生态位差异，社区内的物种可以减少其生态位之间的重叠或发现未开发的环境空间3。选择和表型可塑性已作为推动生态位分化的两个候选过程而发展[4,5]，但它们各自的作用仍有待量化[6]。在这里，我们跟踪了5年多种播种草地中植物高度的变化，将其作为光捕获的候选特征7。我们发现物种间的高度差异随着时间的推移而增加。表型可塑性促进了这种变化，这解释了我们系统中分化的快速设置。通过检查遗传结构的变化，我们还强调了选择的贡献。总之，我们通过可塑性和选择的联合作用，在短时间内通过实验证明了人工草地群落中物种生态位分化的发生。