Lawrence Alice K, Heenan Adel, Williams Gareth J
School of Ocean Sciences, Bangor University, Menai Bridge, Anglesey LL59 5AB, UK.
R Soc Open Sci. 2025 Apr 2;12(4):241254. doi: 10.1098/rsos.241254. eCollection 2025 Apr.
Tropical coral reefs are dynamic, disturbance-driven ecosystems that are heterogeneous across space and time, partly owing to gradients in cross-scale human impacts and natural environmental factors. Localized management interventions that strive to maintain the long-term persistence and function of coral reefs need to be informed by how and why reef habitats vary. Using the 'multivariate dispersion' metric, a statistical approach to measure ecological community variability, we quantified spatial gradients in coral reef benthic communities around Tutuila Island in American Samoa, central South Pacific. Benthic communities with low, medium and high dispersion each had distinct and consistent underlying benthic community characteristics. Low dispersion sites were consistently characterized by high hard coral cover, medium dispersion sites were generally dominated by crustose coralline algae, while high dispersion sites were dominated by turf and fleshy coralline algae. Variability in hard coral and turf algal cover explained 42% of the underlying variation in benthic community dispersion across sites, while site-level gradients in human impacts and environmental factors did not correlate well with variations in benthic community dispersion. The metric should be further tested on temporal data to determine whether it can summarize complex community changes in response to and following acute disturbance.
热带珊瑚礁是动态的、受干扰驱动的生态系统，在空间和时间上具有异质性，部分原因是跨尺度人类影响和自然环境因素的梯度变化。旨在维持珊瑚礁长期存续和功能的局部管理干预措施，需要依据珊瑚礁栖息地的变化方式及原因来制定。我们使用“多变量离散度”指标（一种衡量生态群落变异性的统计方法），对南太平洋中部美属萨摩亚图图伊拉岛周围珊瑚礁底栖生物群落的空间梯度进行了量化。离散度低、中、高的底栖生物群落各自具有独特且一致的潜在底栖生物群落特征。离散度低的区域始终以高硬珊瑚覆盖率为特征，离散度中等的区域通常以壳状珊瑚藻为主，而离散度高的区域则以草皮藻和肉质珊瑚藻为主。硬珊瑚和草皮藻覆盖率的变化解释了各区域底栖生物群落离散度潜在变化的42%，而人类影响和环境因素的区域水平梯度与底栖生物群落离散度的变化相关性不佳。该指标应在时间数据上进一步测试，以确定它是否能够总结复杂的群落变化，以应对急性干扰并跟踪其后续影响。
