Corals escape bleaching in regions that recently and historically experienced frequent thermal stress
Corals escape bleaching in regions that recently and historically experienced frequent thermal stress
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DOI：
10.1098/rspb.2009.0591
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发表时间：
2009-08-22
影响因子：
4.7
通讯作者：
van Woesik, R.
中科院分区：
文献类型：
--
作者：
Thompson, D. M.;van Woesik, R.
珊瑚礁生态系统对当代热应力的反应可能部分是最近或历史上海面温度（SST）变化的结果。为了检验这一假设，我们研究了：（i）SST变化的历史频率与最近的热应力事件（1998年和2005-2006年）期间经历的应力之间是否存在关系;（ii）历史上经历过频繁热异常的珊瑚礁在最近的热应力事件期间不太可能经历珊瑚漂白。对9个去趋势的珊瑚三角洲O-18和Sr/Ca异常记录的检查揭示了SST变化的高频率（5.7年）和低频率（>54年）模式。SST异常的历史频率和最近的热应力之间存在正相关关系;历史上由高频模式主导的站点在这两次事件中经历了比其他站点更大的热应力，并在1998年显示出广泛的珊瑚漂白。尽管如此，在2005-2006年期间，在以高频变异为主的地点，珊瑚尽管经历了高热压力，但白化现象有所减少。这种漂白抗性很可能是1998年极端高温事件后快速定向选择的结果。然而，区域抵抗的好处可能是以珊瑚物种组成的变化为代价的。
The response of coral-reef ecosystems to contemporary thermal stress may be in part a consequence of recent or historical sea-surface temperature (SST) variability. To test this hypothesis, we examined whether: (i) there was a relationship between the historical frequency of SST variability and stress experienced during the most recent thermal-stress events (in 1998 and 2005-2006) and (ii) coral reefs that historically experienced frequent thermal anomalies were less likely to experience coral bleaching during these recent thermal-stress events. Examination of nine detrended coral delta O-18 and Sr/Ca anomaly records revealed a high-(5.7-year) and low-frequency (>54-year) mode of SST variability. There was a positive relationship between the historical frequency of SST anomalies and recent thermal stress; sites historically dominated by the high-frequency mode experienced greater thermal stress than other sites during both events, and showed extensive coral bleaching in 1998. Nonetheless, in 2005-2006, corals at sites dominated by high-frequency variability showed reduced bleaching, despite experiencing high thermal stress. This bleaching resistance was most likely a consequence of rapid directional selection that followed the extreme thermal event of 1998. However, the benefits of regional resistance could come at the considerable cost of shifts in coral species composition.