Mountain regions in Western Europe have gone through a massive rural–urban migration and the collapse of their traditional socioeconomic system. As a result, forest has occupied many old pastures and croplands. In protected areas – such as National Parks – changes in the landscape can affect biodiversity and other services, including the values that motivated their declaration. Any policy decision in these areas requires quantifying the extent and impact of land-cover changes and their consequences on landscape structure and functioning. In this study we analyze the patterns of change in forest cover during six decades in three mountain National Parks in Spain. Our aim is to quantify those patterns, their effects on the landscape, and discuss the potential consequences for the main natural values and services. We assessed changes in forest cover through reclassification of aerial ortophotographs taken in 1956–57 (past images) and 2016–17 (recent images). The three Parks show a relatively low change in total forest area (+5–10%), and a much larger increase in dense forest (+20–30%), with an important effect of land-use legacies, and similar patterns of landscape homogenization. There were fewer but larger forest patches in 2016 than in 1956, and most of the gain in dense forest occurred in core areas (+20%), while transition areas such as edges, bridges or loops decreased between 30 and 55%. Given their potential consequences on biodiversity and other services, these patterns of land-cover change and landscape configuration should be explicitly considered when designing the sustainable management of abandoned landscapes in protected areas.

西欧的山区经历了大规模的农村向城市迁移和传统社会经济体系的崩溃。结果，森林占据了许多古老的牧场和农田。在保护区——例如国家公园——景观的变化会影响生物多样性和其他服务，包括促使他们宣布的价值观。这些领域的任何政策决定都需要量化土地覆盖变化的范围和影响及其对景观结构和功能的影响。在这项研究中，我们分析了西班牙三个山地国家公园 6 年间森林覆盖的变化模式。我们的目标是量化这些模式及其对景观的影响，并讨论对主要自然价值和服务的潜在影响。过去的图像）和 2016-17（最近的图像）。三个公园的森林总面积变化相对较小（+5-10%），而茂密森林的增加幅度更大（+20-30%），土地利用遗产的重要影响，以及类似的模式景观同质化。2016 年的森林斑块数量比 1956 年少但更大，茂密森林的大部分增长发生在核心区域（+20%），而边缘、桥梁或环路等过渡区域减少了 30% 至 55%。鉴于它们对生物多样性和其他服务的潜在影响，在设计保护区废弃景观的可持续管理时，应明确考虑这些土地覆盖变化和景观配置模式。