Unexpectedly, Creation of Temporary Water Bodies Has Increased the Availability of Food and Nesting Sites for Bees (Apiformes)

Abstract

Earthworks, such as embankments or excavations, because of their transient nature, usually do not play any important role in biodiversity protection and promotion in urban areas. However, the results of this study show that pits playing the role of infiltration basins, which are filled with water only in some periods, can provide bees with food resources and nesting sites. They are particularly important in habitats with simplified vegetation structures, e.g., in monoculture habitats. The attractiveness of infiltration basins and ditches as habitats for bees was assessed by comparing species richness and abundance of bee communities found there with those of coniferous forests—pine monocultures (where the reservoirs were created) and clearings. The species richness and abundance of bees in clearings, infiltration ditches, and basins were higher than in forests. Simultaneously, we found that an increase in woody vegetation coverage and the level of shading in the daytime had a negative effect on bee abundance. In contrast, it was positively affected by increasing the mean radius of a belt of predominantly open habitats around sampling sites (herbaceous plants and seedlings of woody plants <60%). In this case, food resources were not a limiting factor of bee occurrence in the study area.