The trophic cascade has emerged as a key paradigm in ecology. Although ecologists have made progress in understanding spatial variation in the strength of trophic cascades, temporal variation remains relatively unexplored. Our review suggests that strong trophic cascades are often transient, appearing when ecological conditions support high consumer abundance and rapidly growing, highly edible prey. Persistent top-down control is expected to decay over time in the absence of external drivers, as strong top-down control favors the emergence of better-defended resources. Temporal shifts in cascade strength—including those driven by contemporary global change—can either stabilize or destabilize ecological communities. We suggest that a more temporally explicit approach can improve our ability to explain the drivers of trophic cascades and predict the impact of changing cascade strength on community dynamics.

中文翻译：

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营养级联的时间变化

营养级联已成为生态学的一个关键范式。尽管生态学家在理解营养级联强度的空间变化方面取得了进展，但时间变化仍然相对未被探索。我们的评论表明，强大的营养级联通常是短暂的，当生态条件支持高消费丰度和快速增长、高度可食用的猎物时，就会出现。在没有外部驱动因素的情况下，持续的自上而下的控制预计会随着时间的推移而减弱，因为强大的自上而下的控制有利于出现更好的防御资源。级联强度的时间变化——包括由当代全球变化驱动的变化——可以稳定或破坏生态群落。