Environmental conditions that vary from year-to-year can be strong drivers of ecological dynamics, including the composition of newly assembled communities. However, ecologists often chalk such dynamics up to "noise" in ecological experiments. Our lack of attention to such "year effects" hampers our understanding of contingencies in ecological assembly mechanisms and limits the generalizability of research findings. Here, we provide examples from published research demonstrating the importance of year effects during community assembly across study systems. We further quantify these year effects with two case studies- a grassland restoration experiment and a study of post-fire conifer recruitment-finding that the effects of initiation year on community composition can dictate community as much, if not more, than the effects of experimental treatments or site. The evidence strongly suggests that year effects are pervasive and profound, and that year effects early in community assembly can drive strong and enduring divergence in community structure and function. Explicit attention to year effects in ecological research serves to illuminate basic ecological principles, allowing for better understanding of contingencies in ecology. Understanding these dynamics also has strong implications for applied ecological research, offering new insight to improve ecological restoration as well as prediction of the consequences of future climate change.

中文翻译：

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年效应：年际变化作为社区集会动态的驱动因素

逐年变化的环境条件可能是生态动态的强大驱动力，包括新聚集社区的组成。然而，生态学家经常将这种动态归结为生态实验中的“噪音”。我们对这种“年效应”缺乏关注阻碍了我们对生态组装机制中的偶然性的理解，并限制了研究结果的普遍性。在这里，我们提供了来自已发表研究的示例，证明了跨研究系统的社区集会期间年份效应的重要性。我们通过两个案例研究进一步量化了这些年份的影响 - 草原恢复实验和火灾后针叶树招募研究 - 发现起始年份对社区组成的影响可以决定社区，如果不是更多的话，比实验处理或部位的效果。证据有力地表明，年份效应是普遍而深刻的，而社区组装早期的年份效应可以推动社区结构和功能的强烈而持久的分化。生态研究中对年份效应的明确关注有助于阐明基本的生态原理，从而更好地理解生态学中的突发事件。了解这些动态也对应用生态研究具有重要意义，为改善生态恢复以及预测未来气候变化的后果提供了新的见解。那一年在社区集会早期的影响会导致社区结构和功能出现强烈而持久的差异。生态研究中对年份效应的明确关注有助于阐明基本的生态原理，从而更好地理解生态学中的突发事件。了解这些动态也对应用生态研究具有重要意义，为改善生态恢复以及预测未来气候变化的后果提供了新的见解。那一年在社区集会早期的影响会导致社区结构和功能出现强烈而持久的差异。生态研究中对年份效应的明确关注有助于阐明基本的生态原理，从而更好地理解生态学中的突发事件。了解这些动态也对应用生态研究具有重要意义，为改善生态恢复以及预测未来气候变化的后果提供了新的见解。