TY  - JOUR
A1  - Peters, Birte
A1  - Keller, Alexander
A1  - Leonhardt, Sara Diana
T1  - Diets maintained in a changing world: Does land-use intensification alter wild bee communities by selecting for flexible generalists?
JF  - Ecology and evolution
N2  - Biodiversity loss, as often found in intensively managed agricultural landscapes, correlates with reduced ecosystem functioning, for example, pollination by insects, and with altered plant composition, diversity, and abundance. But how does this change in floral resource diversity and composition relate to occurrence and resource use patterns of trap-nesting solitary bees? To better understand the impact of land-use intensification on communities of trap-nesting solitary bees in managed grasslands, we investigated their pollen foraging, reproductive fitness, and the nutritional quality of larval food along a land-use intensity gradient in Germany. We found bee species diversity to decrease with increasing land-use intensity irrespective of region-specific community compositions and interaction networks. Land use also strongly affected the diversity and composition of pollen collected by bees. Lack of suitable pollen sources likely explains the absence of several bee species at sites of high land-use intensity. The only species present throughout, Osmia bicornis (red mason bee), foraged on largely different pollen sources across sites. In doing so, it maintained a relatively stable, albeit variable nutritional quality of larval diets (i.e., protein to lipid (P:L) ratio). The observed changes in bee–plant pollen interaction patterns indicate that only the flexible generalists, such as O. bicornis, may be able to compensate the strong alterations in floral resource landscapes and to obtain food of sufficient quality through readily shifting to alternative plant sources. In contrast, other, less flexible, bee species disappear.
KW  - bee decline
KW  - biodiversity exploratories
KW  - foraging
KW  - metabarcoding
KW  - pollen nutrients
KW  - solitary bees
Y1  - 2022
U6  - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:bvb:20-opus-312786
SN  - 2045-7758
VL  - 12
IS  - 5
ER  - 
TY  - JOUR
A1  - Voulgari‐Kokota, Anna
A1  - Ankenbrand, Markus J.
A1  - Grimmer, Gudrun
A1  - Steffan‐Dewenter, Ingolf
A1  - Keller, Alexander
T1  - Linking pollen foraging of megachilid bees to their nest bacterial microbiota
JF  - Ecology and Evolution
N2  - Solitary bees build their nests by modifying the interior of natural cavities, and they provision them with food by importing collected pollen. As a result, the microbiota of the solitary bee nests may be highly dependent on introduced materials. In order to investigate how the collected pollen is associated with the nest microbiota, we used metabarcoding of the ITS2 rDNA and the 16S rDNA to simultaneously characterize the pollen composition and the bacterial communities of 100 solitary bee nest chambers belonging to seven megachilid species. We found a weak correlation between bacterial and pollen alpha diversity and significant associations between the composition of pollen and that of the nest microbiota, contributing to the understanding of the link between foraging and bacteria acquisition for solitary bees. Since solitary bees cannot establish bacterial transmission routes through eusociality, this link could be essential for obtaining bacterial symbionts for this group of valuable pollinators.
KW  - foraging patterns
KW  - nest microbiota
KW  - plant–microbe–pollinator triangle
KW  - pollination network
KW  - solitary bees
KW  - wild bees
Y1  - 2019
U6  - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:bvb:20-opus-201749
SN  - 00
VL  - 2019
IS  - 9
ER  -