Institute for Global Ecology, Florida Institute of Technology, Melbourne, FL, USA.
J Anim Ecol. 2021 May;90(5):1379-1389. doi: 10.1111/1365-2656.13463. Epub 2021 Mar 17.
Increases in the frequency and intensity of acute and chronic disturbances are causing declines of coral reefs world-wide. Although quantifying the responses of corals to acute disturbances is well documented, detecting subtle responses of coral populations to chronic disturbances is less common, but can also result in altered population and community structures. We investigated the population dynamics of two key reef-building Merulinid coral species, Dipsastraea favus and Platygyra lamellina, with similar life-history traits, in the Gulf of Eilat and Aqaba, Red Sea from 2015 to 2018, to assess potential differences in their population trajectories. Demographic processes, which included rates of survival, growth, reproduction and recruitment were used to parametrize integral projection models and estimate population growth rates and the likely population trajectories of both coral species. The survival and reproduction rates of both D. favus and P. lamellina were positively related to coral colony size, and elasticity analyses showed that large colonies most influenced population dynamics. Although both species have similar life-history traits and growth morphologies and are generally regarded as 'stress-tolerant', the populations showed contrasting trajectories-D. favus appears to be increasing whereas P. lamellina appears to be decreasing. As many corals have long-life expectancies, the process of local and regional decline might be subtle and slow. Ecological assessments based on total living coral coverage, morphological groups or functional traits might overlook subtle, species-specific trends. However, demographic approaches capable of detecting subtle species-specific population changes can augment ecological studies and provide valuable early warning signs of decline before major coral loss becomes evident.
急性和慢性干扰的频率和强度增加正在导致全球范围内的珊瑚礁衰退。尽管量化珊瑚对急性干扰的反应已有充分记录，但检测珊瑚种群对慢性干扰的微妙反应则较少见，但也可能导致种群和群落结构的改变。我们调查了红海埃拉特湾和亚喀巴湾两种关键的造礁 Merulinid 珊瑚物种，Dipsastraea favus 和 Platygyra lamellina 的种群动态，它们具有相似的生活史特征，从 2015 年到 2018 年，以评估它们的种群轨迹可能存在的差异。包括生存率、生长率、繁殖率和补充率在内的人口动态被用来参数化整体预测模型，并估计这两个珊瑚物种的种群增长率和可能的种群轨迹。D. favus 和 P. lamellina 的生存率和繁殖率与珊瑚群体大小呈正相关，弹性分析表明，大群体对种群动态的影响最大。尽管这两个物种具有相似的生活史特征和生长形态，通常被认为是“耐受压力的”，但种群表现出相反的轨迹-D. favus 似乎在增加，而 P. lamellina 似乎在减少。由于许多珊瑚的预期寿命较长，局部和区域衰退的过程可能是微妙和缓慢的。基于总活珊瑚覆盖率、形态群或功能特征的生态评估可能会忽略微妙的、特定于物种的趋势。然而，能够检测到微妙的特定于物种的种群变化的人口统计方法可以补充生态研究，并在主要珊瑚损失变得明显之前提供衰退的宝贵早期预警信号。
