Assessing evidence of phase shifts from coral to macroalgal dominance on coral reefs
Assessing evidence of phase shifts from coral to macroalgal dominance on coral reefs
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DOI：
10.1890/08-1781.1
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发表时间：
2009-06-01
期刊：
影响因子：
4.8
通讯作者：
Schutte, Virginia G. W.
中科院分区：
文献类型：
--
作者：
Bruno, John F.;Sweatman, Hugh;Schutte, Virginia G. W.
许多海洋科学家得出结论，珊瑚礁正在走向或被锁定在以海藻为主的状态。然而，由于还没有区域或全球范围内对这种珊瑚礁“相移”的分析，这种现象的严重程度不得而知。我们分析了1996至2006年间对1851个珊瑚礁进行的3581次定量调查，以确定珊瑚礁和珊瑚向大型藻类的相变的频率、地理范围和程度。我们的结果表明，大型藻类取代珊瑚成为主要的底栖生物功能群的情况并不常见，在地理上也没有假设的那么广泛。尽管我们发现了局部大型藻类覆盖率适度增加的证据，特别是在加勒比海，但只有4%的珊瑚礁以大型藻类为主(即50%的覆盖率)。在整个印度-太平洋地区，大型藻类的区域平均覆盖率为9%-12%，大型藻类仅占调查珊瑚礁的1%。1996至2006年间，加勒比的相变严重程度下降，佛罗里达群岛和印度-太平洋没有变化，大堡礁由于珊瑚适度丧失而略有增加。珊瑚礁生态系统对大型藻类水华的抵抗力似乎比想象的更强，这对珊瑚礁管理具有重要意义。
Many marine scientists have concluded that coral reefs are moving toward or are locked into a seaweed-dominated state. However, because there have been no regional- or global-scale analyses of such coral reef "phase shifts,'' the magnitude of this phenomenon was unknown. We analyzed 3581 quantitative surveys of 1851 reefs performed between 1996 and 2006 to determine the frequency, geographical extent, and degree of macroalgal dominance of coral reefs and of coral to macroalgal phase shifts around the world. Our results indicate that the replacement of corals by macroalgae as the dominant benthic functional group is less common and less geographically extensive than assumed. Although we found evidence of moderate local increases in macroalgal cover, particularly in the Caribbean, only 4% of reefs were dominated by macroalgae (i.e., >50% cover). Across the Indo-Pacific, where regional averages of macroalgal cover were 9-12%, macroalgae only dominated 1% of the surveyed reefs. Between 1996 and 2006, phase shift severity decreased in the Caribbean, did not change in the Florida Keys and Indo-Pacific, and increased slightly on the Great Barrier Reef due to moderate coral loss. Coral reef ecosystems appear to be more resistant to macroalgal blooms than assumed, which has important implications for reef management.