McCarthy Orion S, Kelly Emily L A, Akiona Anela K, Clements Samantha M, Martinez Tatiana, Pedersen Nicole E, Peralto Cole, Romero Sarah L, Smelser Mitchell H, Stone Kristy Wong, Sparks Russell T, Smith Jennifer E
Scripps Institution of Oceanography, UC San Diego, La Jolla, California, USA.
World Economic Forum, San Francisco, California, USA.
Glob Chang Biol. 2025 Jan;31(1):e70050. doi: 10.1111/gcb.70050.
High spatial or temporal variability in community composition makes it challenging for natural resource managers to predict ecosystem trajectories at scales relevant to management. This is commonly the case in nearshore marine environments, where the frequency and intensity of disturbance events vary at the sub-kilometer to meter scale, creating a patchwork of successional stages within a single ecosystem. The successional stage of a community impacts its stability, recovery potential, and trajectory over time in predictable ways. Here we demonstrate the value of successional theory for interpreting fine-scale community heterogeneity using Hawaiian coral reefs as a case study. We tracked benthic community dynamics on 36 forereefs over a 6-year period (2017-2023) that captures impacts from high surf events, a marine heatwave, and unprecedented shifts in human behavior due to the COVID-19 pandemic. We document high spatial variation in benthic community composition that was only partially explained by island and environmental regime. Through hierarchical clustering, we identify three distinct community types that appear to represent different successional stages of reef development. Reefs belonging to the same community type exhibited similar rates of change in coral cover and structural complexity over time, more so than reefs located on the same island. Importantly, communities that were indicative of early succession (low coral cover reefs dominated by stress-tolerant corals) were most likely to experience an increase in coral cover over time, while later-stage successional communities were more likely to experience coral decline. Our findings highlight the influence of life history and successional stage on community trajectories. Accounting for these factors, not simply overall coral cover, is essential for designing effective management interventions. Site-specific management that accounts for a community's unique composition and history of disturbance is needed to effectively conserve these important ecosystems.
群落组成在空间或时间上的高度变异性，使得自然资源管理者难以在与管理相关的尺度上预测生态系统的轨迹。近岸海洋环境通常就是这种情况，在那里，干扰事件的频率和强度在亚公里到米的尺度上变化，在单一生态系统内形成了一个由演替阶段组成的拼凑物。一个群落的演替阶段会以可预测的方式影响其稳定性、恢复潜力和随时间的轨迹。在这里，我们以夏威夷珊瑚礁为案例研究，展示了演替理论在解释精细尺度群落异质性方面的价值。我们在6年时间（2017 - 2023年）内跟踪了36个前礁的底栖生物群落动态，这段时间涵盖了大浪事件、海洋热浪以及由于新冠疫情导致的人类行为前所未有的变化所带来的影响。我们记录了底栖生物群落组成的高度空间变异性，而岛屿和环境状况只能部分解释这种变异性。通过层次聚类，我们识别出三种不同的群落类型，它们似乎代表了珊瑚礁发育的不同演替阶段。属于同一群落类型的珊瑚礁，随着时间推移，在珊瑚覆盖度和结构复杂性方面表现出相似的变化速率，比位于同一岛屿上的珊瑚礁更为相似。重要的是，指示早期演替的群落（以耐胁迫珊瑚为主的低珊瑚覆盖度珊瑚礁）随着时间推移最有可能经历珊瑚覆盖度的增加，而后期演替群落则更有可能经历珊瑚减少。我们的研究结果突出了生活史和演替阶段对群落轨迹的影响。考虑这些因素，而不仅仅是总体珊瑚覆盖度，对于设计有效的管理干预措施至关重要。需要针对特定地点进行管理，考虑群落独特的组成和干扰历史，以有效保护这些重要的生态系统。
