Contrasting effects of vineyard type, soil and landscape factors on ground- versus above-ground nesting bees

1. Agricultural intensification and abandonment of traditional agricultural practices are main drivers of current insect declines. The resulting loss of feeding and nesting opportunities has led to a decrease in pollinator populations like wild bees. While the restoration of floral resources has been widely implemented in wild bee conservation, nesting resources, particularly for ground-nesting species, are barely considered.
2. We assessed wild bee diversity in a wine-growing area in Germany in 15 study sites along a soil gradient and evaluated whether wild bees were distinctly affected by different vineyard types (vertically oriented, terraced, abandoned), local conditions (e.g. shrub and flower cover), and landscape factors in response to divergent nesting needs (above-ground vs. ground-nesting).
3. We found that wild bees responded more strongly to the availability of nesting sites than to flower resources. While ground-nesting bees were determined by the suitability of soil aspect..., In brief, more details are given in the manuscript:
Wild bee sampling was carried out from April to August 2019 in a total of three sampling rounds in three vineyard types: vertically oriented, terraced, and fallow (abandoned). At each sampling round, traps were exposed for three consecutive days per plot (18th–20th April, 28th–30th June, 23rd–26th August). For each plot and sampling round we used a set of three differently coloured pan traps, the inside was painted with blue, white, and yellow UV-reflecting paints and filled with water. Traps were placed in the vineyard-type centre at a distance of 3 m from each other and adjusted at the level of the surrounding vegetation.
Wild bees were identified to species level. For analysis, all samples per site were pooled over the three sampling rounds. We assigned species to be ground-nesting or above-ground-nesting following Westrich (2019). Parasitic species, do not build their nests but rather depend on their hosts and were therefore not c..., We provide dataframes as CSV files and metadata for the respective dataframes in text files.