Abstract. Extensively managed grasslands, particularly in mountain regions, are considered to be one of the most diverse agroecosystems worldwide. Their decline due to land use abandonment affects the diversity of both plants and associated pollinators. Extensive grasslands constitute an important habitat type and food resource for hoverflies (syrphids); however, not much is known about the effects of abandonment on this important pollinator group. In the present study, we investigated how abandonment affects species richness and the composition of syrphids in mountainous meadows. We recorded the richness of vascular plants, vegetation cover, flower cover and the surrounding landscape to examine whether and how syrphids are affected by plant and landscape parameters. We investigated the species richness, abundance and species composition of syrphids by sweep netting and by using observation plots in 18 semidry meadows across two Austrian regions and one Swiss region. For each region, we selected three meadows abandoned for more than 20 years and three annually mown non-fertilized meadows. Abandonment or mowing had no significant effect on the total number of syrphid species or individuals or on the number of aphidophagous and non-aphidophagous species and individuals. However, the total number of species and the number of non-aphidophagous species significantly increased with the increasing number of plant species. The surrounding landscape and other plant parameters showed no association with the assessed syrphid parameters. Although syrphids were unaffected by abandonment, higher syrphid species numbers in response to a higher plant richness in annual mown meadows suggest that the management of mountain meadows is beneficial in preserving syrphid richness.

中文翻译：

---

停止管理对奥地利和瑞士山地草甸食蚜蝇（双翅目：食蚜蝇科）的影响

摘要。广泛管理的草原，特别是山区，被认为是世界上最多样化的农业生态系统之一。由于放弃土地使用而导致的下降影响了植物和相关传粉媒介的多样性。广阔的草原是食蚜蝇（syrphids）的重要栖息地类型和食物资源；然而，关于放弃对这一重要传粉媒介群体的影响知之甚少。在本研究中，我们调查了废弃如何影响山地草甸中的物种丰富度和 syrpids 的组成。我们记录了维管植物、植被覆盖、花卉覆盖和周围景观的丰富程度，以检查梅毒是否以及如何受到植物和景观参数的影响。我们调查了物种丰富度，通过在两个奥地利地区和一个瑞士地区的 18 个半干草甸中使用清扫网和观察地块，研究了 syrpids 的丰度和物种组成。对于每个地区，我们选择了三个废弃了 20 多年的草地和三个每年修剪的未施肥的草地。放弃或割草对蚜虫物种或个体的总数或对蚜虫和非蚜虫物种和个体的数量没有显着影响。但物种总数和非蚜虫物种数量随着植物物种数量的增加而显着增加。周围景观和其他植物参数与评估的梅毒参数无关。虽然 syrpids 不受遗弃的影响，