Data from: The role of wild bees and cavity-nesting wasps as ecological indicators of the last traditionally managed meadows in Eastern Europe

The number of wild bees and cavity-nesting wasps is abundant in
agricultural areas and they contribute significantly to ecosystem
services. Due to their specialization in nesting sites
and  food sources, these groups are sensitive to habitat
condition changes and they are therefore important indicators for
environmental impact assessments. As semi-natural habitats are steadily
declining and often understudied, their significance for research is
increasingly recognized. During this research, the role of wild bee
species and cavity-nesting Hymenopteran taxa as indicators was examined,
along the unique combination of high nature value and traditional land use
habitats in Central Europe, Transylvania. Transects and trap nests were
used to test the diversity and abundance of wild bees and cavity-nesting
Hymenopterans in order to identify possible differences between highly
protected and less protected areas. The differences in taxonomic groups
between the sites and the potential effects of landscape structure on wild
bees and cavity-nesting Hymenopterans were also assessed. We detected a
high diversity of wild bee species and a significant species replacement
from one study year to another. Among the nest-building Hymenopteran taxa,
the majority of nests was built by Trypoxylon sp. during both study years,
with a stronger dominance in the second year. The different taxonomic
groups of wild bees and cavity-nesting Hymenopterans showed differences in
their habitat affinities. The majority of the sampled bumblebee species as
well as Trypoxylon sp. had an affinity towards the study sites located
within the highly protected study area. Altogether, we found different
habitat preferences for different Hymenpteran groups (both wild bees and
wasps) and conclude that these groups definitely have the potential to
serve as indicators for differences in the intensity of land use.
cavity-nesting bees, solitary bees, wild bees, landscape structure, spider
prey preference.