Beetle species (Coleoptera) in hayfields and pastures in northern Iceland

The aim of the present study was to investigate the composition and activity of surface-living invertebrates in hayfields and unimproved pastures on three soil types in northern Iceland. Surface-living beetles were collected in pitfall traps over a 1-year period in three unimproved pastures and three managed hayfields, located on sandy, silty and peat soils. Annual management of hayfields included fertilization and hay cutting, whereas pastures were only grazed occasionally by cattle. During the summer season 42 beetle species were collected, dominated by 23 Staphylinidae species, which comprised 77% of all the coleopterans collected. The dominating coleopterans, both in hayfields and pastures, were Oxypoda islandica, Atheta atramentaria and Atomaria analis. A significantly higher number of specimens of all the most common species, and a slightly higher number of beetle species, were detected on pastures than on hayfields. All the most commonly detected beetle species were more abundant on peat soil than on silty or sandy soil, except Tachinus corticinus, which was not detected on peat soil. The activity of beetle species culminated at different times throughout the summer, A. analis in spring, A. atramentaria in summer and O. islandica in autumn. During the winter season 24 beetle species were detected, of which two were not trapped during the summer season. No difference in the number of species or specimens between pastures and hayfields or between the three soil types was observed during the winter season.