National Commission for the Knowledge and Use of Biodiversity, México City, México.
Guanahacabibes National Park, Sandino, Pinar del Río, Cuba.
PeerJ. 2023 Aug 31;11:e15953. doi: 10.7717/peerj.15953. eCollection 2023.
The long-time study of coral reefs with low human impacts can provide information on the effects of regional pressures like climate change, and is an opportunity to document how these pressures are reflected in coral communities. An example of minimal local anthropogenic impacts are the Guanahacabibes coral reefs, located in the westernmost region of Cuba. The objectives of this study were: to evaluate the temporal variability of six benthic biological indicators of coral reefs, and to explore the possible relationship between predictive abiotic variables and biological response variables.
Four coral reef sites were sampled between 2008 and 2017, to analyze biological indicators (living coral cover, fleshy algae index, coral species richness, coral species abundance, coral trait groups species abundance, Functional Reef Index). Seven abiotic variables (wave exposure, sea surface temperature, degree heating week, chlorophyll-a concentration, particulate organic carbon, photosynthetically available radiation, and the diffuse attenuation coefficient) were compiled between 2007 and 2016, from remote sensing datasets, to analyze their relationship with the biological indicators. Permanova statistical analysis was used to evaluate trends in biological variables between sites and years, and Routine Analysis Based on Linear Distances (DISTLM) was used to explore some dependencies between biotic and abiotic variables.
We found significant variability in the temporal analysis, with a decrease in living coral cover, a decline in the predominance of the branching and massive framework reef-building species, a decline in species abundance, and an increase in the fleshy algae index. Some abiotic variables (average of degree heating weeks, standard deviation of the diffuse attenuation coefficient, average of the sea surface temperature, among others) significantly explained the variability of biological indicators; however, determination coefficients were low.
Certain decrease in the functionality of the coral reef was appreciated, taking into account the predominance of secondary and nom-massive framework reef-building species in the last years. A weak association between abiotic and biological variables was found in the temporal analysis. The current scenario of the condition of the coral reefs seems to be regulated by the global effects of climate change, weakly associated effects, and in longer terms.
对人类影响较小的珊瑚礁进行长期研究，可以提供有关气候变化等区域性压力影响的信息，并有机会记录这些压力如何反映在珊瑚群落中。人类活动影响极小的珊瑚礁的一个例子是位于古巴最西部的关纳哈比贝斯珊瑚礁。本研究的目的是：评估六个珊瑚礁底栖生物指标的时间变化，并探索预测生物指标和生物响应指标之间的可能关系。
在 2008 年至 2017 年期间，对四个珊瑚礁地点进行了采样，以分析生物指标（活珊瑚覆盖率、肉质藻类指数、珊瑚物种丰富度、珊瑚物种丰度、珊瑚特征群物种丰度、功能礁指数）。在 2007 年至 2016 年期间，从遥感数据集中收集了 7 个非生物变量（波暴露、海面温度、加热周数、叶绿素-a 浓度、颗粒有机碳、光合有效辐射和漫衰减系数），以分析它们与生物指标的关系。采用 Permanova 统计分析评估了生物变量在站点和年份之间的趋势，采用基于线性距离的常规分析（DISTLM）来探索生物和非生物变量之间的一些依赖关系。
我们发现时间分析存在显著的可变性，活珊瑚覆盖率下降，分枝和块状框架造礁物种的优势下降，物种丰度下降，肉质藻类指数上升。一些非生物变量（平均加热周数、漫衰减系数标准差、海面温度平均值等）显著解释了生物指标的可变性；然而，决定系数较低。
考虑到近年来次要和非块状框架造礁物种的优势，珊瑚礁功能确实有所下降。在时间分析中发现了生物和非生物变量之间的弱关联。当前珊瑚礁状况的情景似乎受到气候变化等全球性影响、弱关联效应和长期影响的调节。
