Abstract:
Rapidly changing conditions alter disturbance patterns, highlighting the need to better understand how the transition from pulse disturbances to more persistent stress will impact ecosystem dynamics. We conducted a global analysis of the impacts of 11 types of disturbances on reef integrity using the rate of change of coral cover as a measure of damage. Then, we evaluated how the magnitude of the damage due to thermal stress, cyclones, and diseases varied among tropical Atlantic and Indo-Pacific reefs and whether the cumulative impact of thermal stress and cyclones was able to modulate the responses of reefs to future events. We found that reef damage largely depends on the condition of a reef before a disturbance, disturbance intensity, and biogeographic region, regardless of the type of disturbance. Changes in coral cover after thermal stress events were largely influenced by the cumulative stress of past disturbances and did not depend on disturbance intensity or initial coral cover, which suggests that an ecological memory is present within coral communities. In contrast, the effect of cyclones (and likely other physical impacts) was primarily modulated by the initial reef condition and did not appear to be influenced by previous impacts. Our findings also underscore that coral reefs can recover if stressful conditions decrease, yet the lack of action to reduce anthropogenic impacts and greenhouse gas emissions continues to trigger reef degradation. We uphold that evidence-based strategies can guide managers to make better decisions to prepare for future disturbances.
摘要:
快速变化的条件改变了扰动模式,强调需要更好地了解从脉冲干扰到更持久的压力的过渡将如何影响生态系统动态。我们使用珊瑚覆盖的变化率作为损害的衡量标准,对11种干扰对珊瑚礁完整性的影响进行了全球分析。然后,我们评估了热应力造成的损伤程度,旋风,热带大西洋和印度太平洋珊瑚礁之间的疾病各不相同,以及热应力和气旋的累积影响是否能够调节珊瑚礁对未来事件的反应。我们发现珊瑚礁的破坏很大程度上取决于扰动前珊瑚礁的状况,扰动强度,和生物地理区域,不管干扰的类型。热应激事件后珊瑚覆盖的变化在很大程度上受到过去扰动累积应力的影响,不依赖于扰动强度或初始珊瑚覆盖,这表明珊瑚群落中存在生态记忆。相比之下,气旋的影响(以及可能的其他物理影响)主要受初始珊瑚礁条件的调节,似乎不受先前影响的影响。我们的发现还强调,如果压力条件减轻,珊瑚礁可以恢复,然而,缺乏减少人为影响和温室气体排放的行动继续引发珊瑚礁退化。我们坚持认为,基于证据的策略可以指导管理者做出更好的决策,为未来的干扰做好准备。