Intensification and homogenization of agricultural landscapes have led to a strong decline in European farmland birds. Agroforestry systems, which were widespread in the past, are regaining attention as they could return structural heterogeneity to agricultural landscapes. However, few studies focus on the effects of such systems on biodiversity and especially bird diversity. We hypothesized that agroforestry systems host a higher alpha and beta diversity of birds compared to open agriculture as well as distinct bird communities. Moreover, we expected that bird communities in temperate Europe and the Mediterranean are differently affected by agroforestry systems. In this study, we assessed breeding bird diversity via audio recordings in nineteen mature agroforestry plots, comprising both silvoarable and silvopastoral systems distributed across seven countries in temperate and Mediterranean Europe. For comparison, bird diversity was also assessed in nearby open agricultural land, forests, and orchards. Bird species richness in agroforestry was more than doubled compared to open agricultural land and similar to the diversity found in forests and orchards. Community composition and within-habitat beta diversity differed between the habitat types and between European regions. While temperate agroforestry systems hosted generalist and woody habitat species, bird communities in Mediterranean agroforestry were composed of species from both open and woody habitats. Beta diversity was significantly higher in agroforestry than in open agriculture in temperate systems but not in the Mediterranean. Our study demonstrates that agroforestry systems represent a valuable habitat for breeding birds in European agricultural landscapes. A wider adoption of these systems could thus contribute to halting and reversing the decline in bird diversity, especially in temperate agricultural landscapes.

农业景观的集约化和同质化导致欧洲农田鸟类大幅减少。过去广泛存在的农林业系统正在重新受到关注，因为它们可以恢复农业景观的结构异质性。然而，很少有研究关注此类系统对生物多样性，特别是鸟类多样性的影响。我们假设，与开放农业和独特的鸟类群落相比，农林复合系统拥有更高的鸟类α和β多样性。此外，我们预计欧洲温带和地中海的鸟类群落会受到农林复合系统的不同影响。在这项研究中，我们通过十九个成熟农林业地块的录音评估了繁殖鸟类的多样性，这些地块包括分布在欧洲温带和地中海七个国家的林地和林牧系统。为了进行比较，还评估了附近开放农田、森林和果园的鸟类多样性。与开放农田相比，农林业中鸟类物种的丰富度增加了一倍多，与森林和果园中的多样性相似。栖息地类型和欧洲地区之间的群落组成和栖息地内β多样性有所不同。虽然温带农林业系统拥有普通和木本栖息地物种，但地中海农林业中的鸟类群落由来自开放和木本栖息地的物种组成。在温带系统中，农林业的β多样性显着高于开放农业，但在地中海地区则不然。我们的研究表明，农林业系统是欧洲农业景观中鸟类繁殖的宝贵栖息地。因此，更广泛地采用这些系统可能有助于阻止和扭转鸟类多样性的下降，特别是在温带农业景观中。