Unexpected high vulnerability of functions in wilderness areas: evidence from coral reef fishes

High species richness is thought to support the delivery of multiple ecosystem functions and services under changing environments. Yet, some species might perform unique functional roles while others are redundant. Thus, the benefits of high species richness in maintaining ecosystem functioning are uncertain if functions have little redundancy, potentially leading to high vulnerability of functions. We studied the natural propensity of assemblages to be functionally buffered against loss prior to fishing activities, using functional trait combinations, in coral reef fish assemblages across unfished wilderness areas of the Indo-Pacific: Chagos Archipelago, New Caledonia and French Polynesia. Fish functional diversity in these wilderness areas is highly vulnerable to fishing, explained by species- and abundance-based redundancy packed into a small combination of traits, leaving most other trait combinations (60%) sensitive to fishing, with no redundancy. Functional vulnerability peaks for...学界普遍认为，在环境持续变化的背景下，较高的物种丰富度（species richness）可助力多种生态系统功能与服务（ecosystem functions and services）的实现。然而，部分物种可能承担独特的功能角色，其余物种则存在功能冗余（functional redundancy）。因此，若某类生态系统功能（ecosystem functioning）的冗余度极低，那么高物种丰富度在维持生态系统功能方面的益处便难以确定，这可能会使相关功能面临极高的脆弱性。我们以印度-太平洋海域未受捕捞的荒野区域（涵盖查戈斯群岛、新喀里多尼亚与法属波利尼西亚）内的珊瑚礁鱼类群落（coral reef fish assemblages）为研究对象，通过功能性状（functional trait）组合分析，探究了捕捞活动发生前，鱼类群落天然具备的功能抗损缓冲能力。上述荒野区域的鱼类功能多样性对捕捞活动极具敏感性：基于物种与种群丰度的功能冗余仅集中于少量性状组合，致使剩余60%的性状组合均对捕捞活动缺乏抵抗力且无功能冗余。功能脆弱性于……达到峰值