Trees and shrubs expanded in the last decades in European mountains due to land abandonment and the decrease in grazing pressure, and are expected to further spread also due to climate change. As a consequence of low forage quality and topographic constraints, the management of mountain environments dominated by woody vegetation with livestock is often challenging. Silvopastoral systems based on cattle hardy breeds able to forage on woody plants, such as Highland cattle, could be a suitable option for the management and restoration of such environments. In this study, we used direct observations to explore the foraging behavior of Highland cattle in four study areas across the western Alps. In particular, we assessed: (1) cattle diet composition, (2) the selection for more than 30 tree and shrub species, and (3) the relationships between species consumption and their abundance in the environment. Highland cattle fed on a mixture of both woody and herbaceous species, including between 15 and 46% of woody plants in the diet. Some trees (e.g., Celtis australis, Fraxinus spp., and Populus tremula) and shrubs (e.g., Frangula alnus, Rhamnus spp., and Rubus idaeus) were positively selected by cattle, thus they could be an important forage supplement to their diet. Moreover, the results highlighted that relative species consumption generally increased with increasing species abundance in the environment, suggesting that this cattle breed could be suitable to control shrub expansion in highly encroached areas. The outcomes of this study can support the development of targeted silvopastoral systems in the Alps.

由于土地撂荒和放牧压力减少，过去几十年欧洲山区的树木和灌木面积不断扩大，而且由于气候变化，预计还会进一步蔓延。由于草料质量低下和地形限制，以木本植被和牲畜为主的山区环境的管理往往具有挑战性。以能够以木本植物为食的耐寒牛品种（例如高地牛）为基础的林牧系统可能是管理和恢复此类环境的合适选择。在这项研究中，我们利用直接观察来探索阿尔卑斯山西部四个研究区域的高地牛的觅食行为。我们特别评估了：(1) 牛的饮食组成，(2) 30 多种树木和灌木物种的选择，以及 (3) 物种消耗与其在环境中的丰度之间的关系。高地牛以木本和草本物种的混合物为食，其中木本植物的含量为 15% 至 46%。一些乔木（如朴树、水曲柳和欧洲山杨）和灌木（如桤木、鼠李属和悬钩子）被牛积极选择，因此它们可以成为其饮食的重要饲料补充。此外，结果强调，相对物种消耗通常随着环境中物种丰度的增加而增加，这表明该牛品种可能适合控制高度侵蚀地区的灌木扩张。这项研究的结果可以支持阿尔卑斯山有针对性的林牧系统的发展。