Open semi-natural ecosystems have been historically shaped by anthropogenic land-use, and the abandonment or intensification of these activities implied a detrimental alteration of their landscapes. Extensive sheep grazing has gradually decreased during the 20th century in Mediterranean steppes, triggering changes across all taxa. Here, we address the effect of sheep grazing on both arthropod biomass and space use by insectivorous steppe birds, using an endangered passerine as a model species. We found that biomass of different arthropod groups peaked at intermediate levels of grazing, and that both short-term grazing (affecting arthropod biomass) and long-term grazing (affecting vegetation structure) explain space use by insectivorous birds, whereas only long-term processes are decisive for bird territory establishment. Our results emphasise the role of sustained moderate grazing intensity in the conservation of steppe biodiversity. In the current decline context of extensive sheep grazing, agricultural policies should prioritise these practices to ensure the persistence of open semi-natural ecosystems

开放的半自然生态系统在历史上一直受到人为土地利用的影响，而这些活动的放弃或集约化意味着其景观的有害改变。20 世纪，地中海大草原上广泛放牧的绵羊逐渐减少，引发了所有类群的变化。在这里，我们使用濒临灭绝的雀形目动物作为模型物种，解决了绵羊放牧对节肢动物生物量和食虫草原鸟类空间利用的影响。我们发现不同节肢动物群的生物量在中间放牧水平达到峰值，短期放牧（影响节肢动物生物量）和长期放牧（影响植被结构）都可以解释食虫鸟类的空间利用，而只有长期过程对鸟类领地的建立起决定性作用。我们的结果强调了持续适度放牧强度在保护草原生物多样性方面的作用。在目前绵羊放牧量下降的背景下，农业政策应优先考虑这些做法，以确保开放的半自然生态系统的持续存在