Three decades of degradation lead to diminished impacts of severe hurricanes on Caribbean reefs
Three decades of degradation lead to diminished impacts of severe hurricanes on Caribbean reefs
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DOI：
10.1002/ecy.2587
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发表时间：
2019-03-01
期刊：
影响因子：
4.8
通讯作者：
Edmunds, Peter J.
中科院分区：
文献类型：
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作者：
Edmunds, Peter J.
大型热带风暴是一种破坏性现象，对多种生物群落的群落动态产生巨大影响。几十年来，人们一直在描述风暴对珊瑚礁的影响，因此人们预计，未来的风暴应该会产生与过去记录的类似的影响。这一预期依赖于风暴强度将保持不变的假设，受影响的珊瑚礁群落与最近的珊瑚礁群落相似;这两个假设都不正确。这项研究量化了两个五级飓风对美属维尔京群岛圣约翰珊瑚礁的影响，其中31年的时间序列分析揭示了慢性珊瑚死亡率，大型藻类丰度增加，以及造成急性珊瑚死亡的五个主要飓风。在这些趋势的背景下，最近的风暴，飓风伊尔玛和玛丽亚（2017年9月），对珊瑚覆盖的影响是温和的。虽然平均绝对珊瑚覆盖率下降1-4%，视乎地点而定，但这些影响在统计上是无法辨别的。在大型藻类数量增加几十年之后，这一功能组对最近的飓风作出了反应，在绝对和相对尺度上大量增加。几十年的长期死亡改变了圣约翰的珊瑚组合，形成了能够抵御严重风暴的退化群落。
Major tropical storms are destructive phenomena with large effects on the community dynamics of multiple biomes. On coral reefs, their impacts have been described for decades, leading to the expectation that future storms should have effects similar to those recorded in the past. This expectation relies on the assumption that storm intensities will remain unchanged, and the impacted coral reef communities are similar to those of the recent past; neither assumption is correct. This study quantified the effects of two category five hurricanes on the reefs of St. John, U.S. Virgin Islands, where 31 yr of time-series analyses reveal chronic coral mortality, increasing macroalgal abundance, and five major hurricanes that caused acute coral mortality. Contextualized by these trends, the effects of the most recent storms, Hurricanes Irma and Maria (September 2017), on coral cover were modest. While mean absolute coral cover declined 1-4% depending on site, these effects were not statistically discernable. Following decades of increasing abundance of macroalgae, this functional group responded to the recent hurricanes with large increases in abundance on both absolute and relative scales. Decades of chronic mortality have changed the coral assemblages of St. John to create degraded communities that are resistant to severe storms.