Analysis of the richness of Staphylinidae (Coleoptera) on different scales of a sub-Andean rural landscape in Colombia

In the mid-watershed of the Nima River in the Colombian Central Cordillera, the richness of staphylinids was estimated in association with 35 landscape elements classified as mature forest, secondary forest, riparian corridors, pastures and cypress plantations. For each element, two linear transects were traced, each one with six sample units, consisting of a pitfall trap and a 1 m(2) sample of leaf litter, processed in mini-Winkler sacks. There were 2623 specimens grouped into 139 recognizable taxonomic units; 13 subfamilies were recorded: Pselaphinae, Aleocharinae, Paederinae, Staphylininae, Tachyporinae, Osoriinae, Oxytelinae, Piestinae, Scaphidiinae, Euaesthetinae, Megalopsidiinae, Steninae and Omaliinae. The subfamilies with the greatest richness were Pselaphinae (40 species), Aleocharinae (39) and Paederinae (22). The highest number of species was found in the secondary forests (105 species), followed by the riparian corridors (98); whereas the mature forest was the element with the fewest species (30). The diversity of species components (alpha, beta and gamma) was analyzed using the additive partition model based on four spatial scales: sampling units, transects, elements and types of vegetative cover. The elements and types of ground cover scales were the main contributors to total richness percentages. The subfamilies Aleocharinae, Paederinae, Pselaphinae and Staphylininae had component diversity patterns that were equal to the overall assemblage. A significant correlation of the richness of each subfamily with that of the assemblage was found.