Understanding differential patterns in coral reef recovery: chronic hydrodynamic disturbance as a limiting mechanism for coral colonization
Understanding differential patterns in coral reef recovery: chronic hydrodynamic disturbance as a limiting mechanism for coral colonization
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了解珊瑚礁恢复的差异模式：慢性水动力扰动作为珊瑚殖民的限制机制
DOI：
10.3354/meps12714
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发表时间：
2018
影响因子：
2.5
通讯作者：
P. Halpin
中科院分区：
文献类型：
--
作者：
T. Viehman;James L. Hench;S. Griffin;Amit Malhotra;K. Egan;P. Halpin
珊瑚礁受到许多自然干扰，干扰后珊瑚的恢复潜力取决于随后受影响生境的重新定殖。我们检查了受船舶搁浅干扰的2个近端珊瑚礁的不同恢复轨迹，这导致了明确划定的基底改变区域。从2009年到2013年，在未受干扰的参考区以及受干扰的路面和碎石区，大约每年对珊瑚的繁殖、存活和群落结构变化进行一次干扰后测量。尽管最初的物理干扰相似，但不同地点之间存在显著差异，在受干扰的人行道上，珊瑚的繁殖和存活率高于碎石底部、参考珊瑚礁或修复结构。随后由碎石移动引起的偶发性干扰可能是驱动不同恢复模式的机制。为了估计当地的水动力条件是否足以调动碎石，我们结合了长期监测、水动力建模和碎石运输力学来预测基质迁移的潜力。在研究地点进行的长期水动力模型模拟显示，在多个事件中，底部轨道速度超过了通过滑动或倾覆来动员碎石所需的阈值。我们的分析表明，波浪能每年多次调动碎石基质，这表明相对于路面基质上的珊瑚，珊瑚新生体的生存受到物理限制。持续的动员可能建立一个积极的反馈循环，在这个循环中，持续的碎石动员造成额外的机械侵蚀或破碎，并向较小的碎石尺寸转移，随后在较低的水动力强迫水平下动员，从而受到更频繁和持续的干扰。多种水动力干扰和不稳定的基材的结合限制了珊瑚的恢复，从而导致栖息地的长期丧失。
Coral reefs are subject to numerous physical disturbances, and post-disturbance coral recovery potential depends on subsequent re-colonization of impacted habitat. We examined divergent recovery trajectories at 2 proximal reefs disturbed by ship groundings that resulted in clearly delineated areas of altered substrate. Post-disturbance measurements of coral recruitment, survival, and changes in community structure were made approximately annually from 2009−2013 in undisturbed reference areas as well as disturbed pavement and rubble areas. Despite similar initial physical disturbances, there were marked differences between sites, with higher coral recruitment and survival on disturbed pavement than rubble bottom, reference reef, or restoration structures. Subsequent episodic disturbances from rubble mobilization could be a mechanism driving the divergent recovery patterns. To estimate whether local hydrodynamic conditions were sufficient to mobilize rubble, we used a combination of long-term monitoring, hydrodynamic modeling, and rubble transport mechanics to hindcast the potential for substrate mobility. Long-term model simulations of hydrodynamic forcing at the study sites showed multiple events where bottom-orbital velocities exceeded thresholds required to mobilize rubble via sliding or overturning. Our analyses indicate that wave energy mobilizes rubble substrate multiple times annually and suggests a physical limitation on survival of coral recruits relative to those on pavement substrate. Continued mobilizations may establish a positive feedback loop in which continued rubble clast mobilizations cause additional mechanical erosion or breakage and a shift to smaller rubble sizes that would subsequently mobilize at a lower level of hydrodynamic forcing and thus become subject to more frequent and sustained disturbances. The combination of multiple hydrodynamic disturbances and unstable substrate limits coral recovery and thus contributes to prolonged habitat loss.
影响因子：
2.2
作者：
Sander R. Scheffersa;Jay Haviserb;Tony Brownea;Anja Scheffersa
通讯作者：
Sander R. Scheffersa;Jay Haviserb;Tony Brownea;Anja Scheffersa