Abstract Protected areas (PAs) have been established to promote the long-term conservation of biodiversity and ecosystems. Wetlands, which represent a key habitat worldwide, have been largely destroyed, particularly in more industrialized countries, and their remnants are now often preserved by PA networks, especially in the European Union. We tested the effectiveness of a PA network of 26 small wetlands in preserving wetland birds over a thirty-year period (1989–2019), by investigating changes in species occurrence and relating them to the species' ecological specialization. Out of 23 species, 10 showed an increase in occurrence, 7 remained stable and 6 declined. The number of occupied habitats (between 1 and 8) was significantly associated with the species' trend: specialized species decline, whereas generalists increased. Species with increasing occurrence mostly included common birds, whereas the declining ones were all species with an unfavourable conservation status at the national level. Generalist species increased their occurrence rates, whereas species with stricter, more specialized requirements, generally underwent contraction, suggesting that the conservation of isolated wetlands, managed according to criteria not strictly focused on birds, is not enough to preserve the more specialized species. The proper management of key habitats and the increase of ecological connectivity in the wetland system are crucial for the conservation of wetland-specialist birds.

中文翻译：

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在 30 年的时间里，小型保护区网络偏爱通才但不专业的湿地鸟类

摘要 保护区（PA）的建立是为了促进生物多样性和生态系统的长期保护。湿地是世界范围内的重要栖息地，已在很大程度上遭到破坏，特别是在工业化程度更高的国家，其残余物现在通常由 PA 网络保存，尤其是在欧盟。我们通过调查物种发生的变化并将它们与物种的生态专业化联系起来，测试了由 26 个小型湿地组成的 PA 网络在三十年期间（1989-2019 年）保护湿地鸟类的有效性。在 23 个物种中，10 个出现增加，7 个保持稳定，6 个下降。占据栖息地的数量（1 到 8 个）与物种趋势显着相关：专门物种减少，而通才增加。出现增加的物种主要包括普通鸟类，而减少的物种都是国家一级保护状况不佳的物种。通才物种增加了它们的出现率，而具有更严格、更专业化要求的物种通常会经历收缩，这表明根据不严格针对鸟类的标准进行管理的孤立湿地的保护不足以保护更专业化的物种。关键栖息地的适当管理和湿地系统生态连通性的增加对于湿地专家鸟类的保护至关重要。通才物种增加了它们的出现率，而具有更严格、更专业化要求的物种通常会经历收缩，这表明根据不严格针对鸟类的标准进行管理的孤立湿地的保护不足以保护更专业化的物种。关键栖息地的适当管理和湿地系统生态连通性的增加对于湿地专家鸟类的保护至关重要。通才物种增加了它们的出现率，而具有更严格、更专业化要求的物种通常会经历收缩，这表明根据不严格针对鸟类的标准进行管理的孤立湿地的保护不足以保护更专业化的物种。关键栖息地的适当管理和湿地系统生态连通性的增加对于湿地专家鸟类的保护至关重要。