Biome degradation characterizes the Anthropocene Epoch, and modern ecology is deeply involved with describing the changes underway. Most research has focused on the role of acute disturbances in causing conspicuous changes in ecosystem structure, which leads to an underappreciation of the chronic effects causing large changes through the cumulative effects of small perturbations over decades. Coral reefs epitomize this trend, because the changes in community structure are profound, yet the data to quantify these effects are usually insufficient to evaluate the relative roles of different disturbance types. Here, four decades of surveys from two coral reefs (9 and 14 m depth) off St. John, US Virgin Islands, are used to quantify the associations of acute and chronic events with the changes in benthic community structure. These reefs profoundly changed over 36 years, with coral death altering species assemblages to depress abundances of the ecologically important coral Orbicella spp. and elevating the coverage of macroalgae and crustose coralline algae/turf/bare space (CTB). Linear mixed models revealed the prominent role of chronic variation in temperature in accounting for changes in coverage of corals, macroalgae, and CTB, with rising temperature associated with increases in coral cover on the deep reef, and declines on the shallow reef. Hurricanes were also associated with declines in coral cover on the shallow reef, and increases on the deep reef. Multivariate analyses revealed strong associations between community structure and temperature, but weaker associations with hurricanes, bleaching, and diseases. These results highlight the overwhelming importance of chronically increasing temperature in altering the benthic community structure of Caribbean reefs.

中文翻译：

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十年尺度时间序列凸显了人类世长期扰动在驱动生态系统崩溃中的作用


生物群落退化是人类世的特征，现代生态学深入描述了正在发生的变化。大多数研究都集中在急性扰动对生态系统结构造成显着变化的作用上，这导致人们低估了通过几十年来小扰动的累积效应而导致巨大变化的慢性影响。珊瑚礁体现了这一趋势，因为群落结构的变化是深刻的，但量化这些影响的数据通常不足以评估不同干扰类型的相对作用。在这里，对美属维尔京群岛圣约翰附近的两个珊瑚礁（深度为 9 米和 14 米）进行了四十年的调查，用于量化急性和慢性事件与底栖群落结构变化之间的关联。 36 年来，这些珊瑚礁发生了深刻的变化，珊瑚死亡改变了物种组合，从而降低了具有重要生态意义的珊瑚 Orbicella spp 的丰度。提高大型藻类和甲壳珊瑚藻/草皮/裸露空间（CTB）的覆盖率。线性混合模型揭示了温度的长期变化在解释珊瑚、大型藻类和 CTB 覆盖范围变化方面的显着作用，温度上升与深部珊瑚礁珊瑚覆盖范围的增加有关，而浅层珊瑚礁上珊瑚覆盖范围的下降则与之相关。飓风还导致浅礁珊瑚覆盖减少，深礁珊瑚覆盖增加。多变量分析显示群落结构与温度之间存在很强的关联，但与飓风、白化和疾病之间的关联较弱。这些结果凸显了长期升高的温度对于改变加勒比珊瑚礁的底栖群落结构的压倒性重要性。