Theories and models attempt to explain how and why particular plant species grow together at particular sites or why invasive exotic species dominate plant communities. As local climates change and human‐use degrades and disturbs ecosystems, a better understanding of how plant communities assemble is pertinent, particularly when restoring grassland ecosystems that are frequently disturbed. One such community assembly theory is priority effects, which suggests that arrival order of species into a community alters plant–plant interactions and community assembly. Theoretically, priority effects can have lasting effects on ecosystems and will likely be altered as the risk of invasion by exotic species increases. It is difficult to predict how and when priority effects occur, as experimental reconstruction of arrival order is often difficult in adequate detail. As a result, limited experimental studies have explored priority effects on plant community assembly and plant invasions. To determine if and how priority effects affect the success of invasive species, we conducted a greenhouse study exploring how the arrival order of an invasive grass, Bromus tectorum, affects productivity and community composition when grown with native grasses. We found evidence for priority effects, as productivity was positively related to dominance of B. tectorum and was greater the earlier B. tectorum arrived. This suggests that priority effects could be important for plant communities as the early arrival of an invasive species drastically impacted the productivity and biodiversity of our system at the early establishment stages of plant community development.

中文翻译：

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优先权：与原生草种一起种植时，入侵草（凤尾鹤）的到达顺序如何改变生产力和植物群落结构

理论和模型试图解释特定植物物种如何以及为何在特定地点一起生长，或者为什么外来入侵物种主导植物群落。随着当地气候的变化以及人类使用的退化和干扰生态系统，对植物群落如何更好地了解具有重要意义，特别是在恢复经常受到干扰的草原生态系统时。一种这样的社区集会理论是优先效应，它表明物种进入社区的顺序改变了植物间的相互作用和社区集会。从理论上讲，优先权影响可以对生态系统产生持久影响，并可能随着外来物种入侵的风险增加而改变。很难预测优先效果如何以及何时发生，由于通常很难对到达顺序进行实验性的重建。结果，有限的实验研究已经探索了对植物群落组装和植物入侵的优先作用。为了确定优先效应是否以及如何影响入侵物种的成功，我们进行了温室研究，探讨了入侵草的到达顺序如何，旱雀麦，与原生草生长的影响生产力和群落组成。我们发现了优先效应的证据，因为生产力与权杖的支配地位成正比，并且比权杖更早到达。这表明优先效果对于植物群落可能是重要的，因为在植物群落发展的早期建立阶段，入侵物种的早日到来极大地影响了我们系统的生产力和生物多样性。