Time-integrated thermal bleaching thresholds of reefs and their variation on the Great Barrier Reef
Time-integrated thermal bleaching thresholds of reefs and their variation on the Great Barrier Reef
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DOI：
10.3354/meps229073
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发表时间：
2002-01-01
影响因子：
2.5
通讯作者：
Berkelmans, R
中科院分区：
文献类型：
--
作者：
Berkelmans, R
了解可能导致珊瑚礁珊瑚白化的主要环境变量的临界水平，对于进行气候变化对珊瑚礁的潜在影响的风险评估至关重要。这些知识也可以用来提供大规模白化事件的早期预警。许多因素造成难以确定珊瑚白化的临界水平。这些因素包括多种压力源可能涉及漂白，引起漂白反应所需的压力持续时间随温度而变化，并且已知漂白触发因素在空间，时间和物种上是可变的。在这项研究中，我确定海表温度（SST）是预测珊瑚白化最重要的参数，从10到12年间从大堡礁（GBR）两个地点的气象站收集的4个可能的环境变量：温度、风速、太阳辐射和气压。预测的白化响应曲线是根据13个地点的高分辨率原位温度记录和珊瑚白化的历史观测构建的，这些曲线近似于热敏（通常是优势）珊瑚物种白化的全珊瑚礁应力响应阈值。在大陆架中部和外大陆架珊瑚礁的情况下，珊瑚种群的热敏性存在明显的空间趋势，与横跨大陆架的位置和纬度相对应，这表明在小（10s公里）和大（100s至1000s公里）的空间尺度上发生了相当大的热适应。近海珊瑚礁的白化曲线与纬度不一致，变化更大，反映了温度制度更大的局地尺度变异性。
Knowledge of the critical levels for key environmental variables that are likely to cause bleaching in reef corals is of fundamental importance in conducting risk assessments of potential climate-change effects on coral reefs. Such knowledge can also be used to provide early warning of mass bleaching events. A number of factors have contributed to the difficulty in determining critical levels for coral bleaching. These factors include the fact that multiple stressors may be involved in bleaching, the duration of stress required to elicit a bleaching response varies with temperature, and bleaching triggers are known to be variable in space, time and by species. In this study, I identify sea surface temperature (SST) as the most important parameter for predicting coral bleaching from 4 possible environmental variables collected over 10 to 12 yr from weather stations at 2 locations on the Great Barrier Reef (GBR): temperature, wind speed, solar radiation and barometric pressure. Predicted bleaching-response curves are constructed from high-resolution in situ temperature records and historical observations of coral bleaching for 13 locations, These curves approximate reef-wide stress-response thresholds for bleaching of thermally sensitive (and often dominant) coral species. Distinct spatial trends exist in the thermal sensitivity of coral populations that correspond with position across the shelf and latitude in the case of mid- and outer-shelf reefs, This suggests that considerable thermal adaptation has taken place over small (10s of km) and large (100s to 1000s of km) spatial scales. Bleaching curves for inshore reefs do not correspond with latitude and are more variable, reflecting greater local-scale variability in temperature regimes.