Small and medium-sized islands are acutely exposed to climate change and ecosystem degradation, yet the extent to which uncertainty is systematically addressed in scientific assessments of their ecosystem services remains poorly understood. This study revisits 226 peer-reviewed articles drawn from two global systematic reviews on island ecosystem services and climate change, applying a structured post hoc analysis to evaluate how uncertainty is treated across methods, service categories, ecosystem realms, and decision contexts. Studies were classified according to whether uncertainty was explicitly analysed, just mentioned, or ignored. Only 30 percent of studies incorporated uncertainty explicitly, while more than half did not address it at all. Scenario-based approaches dominated uncertainty assessment, whereas probabilistic and ensemble-based frameworks remained limited. Cultural ecosystem services and extreme climate impacts exhibited the lowest levels of uncertainty integration, and few studies connected uncertainty treatment to policy relevant decision frameworks. Weak or absent treatment of uncertainty emerges as a structural challenge in island systems, where narrow ecological thresholds, strong land-sea coupling, limited spatial buffers, and reduced institutional redundancy amplify the consequences of decision-making under incomplete knowledge. Systematic mapping of how uncertainty is framed, operationalised, or neglected reveals persistent methodological and conceptual gaps and informs concrete directions for strengthening uncertainty integration in future island-focused ecosystem service and climate assessments. Embedding uncertainty more robustly into modelling practices, participatory processes, and policy tools is essential for enhancing scientific credibility, governance relevance, and adaptive capacity in insular socio-ecological systems.

翻译：中小型岛屿极易受到气候变化和生态系统退化的影响，然而科学评估对其生态系统服务的不确定性处理程度仍鲜为人知。本研究重新审视了来自两项全球性岛屿生态系统服务与气候变化系统综述的226篇同行评议文章，采用结构化的事后分析方法，评估了不确定性在方法、服务类别、生态系统领域和决策情境中的处理方式。研究根据不确定性是否被明确分析、仅提及或忽略进行分类。仅有30%的研究明确纳入了不确定性分析，而超过一半的研究完全未涉及该问题。基于情景的方法主导了不确定性评估，而概率性和集成式框架的应用仍然有限。文化生态系统服务和极端气候影响表现出最低水平的不确定性整合，且极少研究将不确定性处理与政策相关的决策框架相联系。不确定性处理的薄弱或缺失成为岛屿系统的一个结构性挑战——在这些系统中，狭窄的生态阈值、强烈的陆海耦合、有限的空间缓冲和制度冗余度的降低，放大了知识不完整条件下决策的后果。通过系统梳理不确定性的界定、操作化或忽视方式，本研究揭示了持续存在的方法论与概念缺口，并为加强未来以岛屿为核心的生态系统服务与气候评估中的不确定性整合指明了具体方向。将不确定性更稳健地嵌入建模实践、参与式过程和政策工具，对于提升岛屿社会生态系统的科学可信度、治理相关性和适应能力至关重要。