Masterarbeit Trap-nesting bees and wasps in faba bean landscapes

Pollination is an important ecosystem service, which is endangered by wild pollinator declines due to agricultural intensification. Important factors threatening wild bees are the loss of suitable nesting sites and the availability of floral resources. Mass flowering crops can contribute to biodiversity conservation and restoration in agricultural landscapes, since they provide pollen and nectar resources for insects. A positive effect of oilseed rape, flowering early in the season, on wild bees has been already shown. However, the continuous supply of food resources throughout the whole season is of major importance for the survival of pollinators. One important crop flowering during mid-Summer is the faba bean, which offers pollen and nectar through the flowers and extrafloral nectaries.
We will analyze the effect of the faba bean (Vicia faba) on trap-nesting solitary bees and wasps as well as their parasitoids. We aim to investigate, whether the mid-season food supply provided by faba beans enhances the number of nests, number of brood cells and the species richness of trap-nesting bees and wasps and influences their parasitism rates and whether the percentage of oilseed rape or semi-natural habitats in the landscape play a role.
In April of 2018 we set up 10 trap nests at field margins in 22 paired landscapes in Germany, i.e. 11 landscapes with faba bean cultivation and 11 control landscapes without grain legumes. Landscapes were 1km x 1km big and trap nests were equally spread over the whole landscape. Trap nests were collected in October, all occupied nests were sorted out and stored in a cooling chamber. Individual nests need to be analyzed in the laboratory. The nests will be identified, total number of brood cells, the number of parasitized brood cells and the number of dead cells due to other causes than parasitoids will be recorded. Afterwards, statistical analyses will be conducted.
This study is part of the RELEVANT project (Regulating ecosystem services in crop rotations with faba beans (Vicia faba) and peas (Pisum sativum): Quantification, evaluation and realization) (https://www.thuenen.de/index.php?id=6817&L=0).
Laboratory work may be started as soon as possible.

If you are interested in this master thesis please contact:
Nicole Beyer or Prof Dr. Catrin Westphal
Functional Agrobiodiversity
Department of Crop Sciences
Georg-August-University Göttingen
Phone: +49 551 / 39-33739 or 39-22257
nicole.beyer@uni-goettingen.de
cwestph@gwdg.de

Masterarbeit Wildbienen auf Ackerwildkrautschutzflächen

Im Rahmen von Agrarumweltmaßnahmen werden im Landkreis Göttingen rund 50 ha Ackerland ackerwildkrautgerecht bewirtschaftet, um gefährdete Pflanzenarten zu schützen (Verzicht auf Dünger und Biozide). Die Segetalflora dieser Gebiete ist äußerst artenreich (z.T. mehr als 100 Blütenpflanzenarten pro Acker), viele dieser Arten sind wertvolle Nahrungspflanzen für spezialisierte Wildbienen, anders als viele in verbreiteten Blühmischungen enthaltene Arten wie Phacelia.

Im Rahmen dieser Masterarbeit soll im Sommer 2020 untersucht werden, welche Wildbienenarten durch den Schutz der Ackerwildkräuter und dem daraus folgenden natürlichen Blütenreichtum profitieren. Untersucht wird die Relevanz als Nahrungsraum, aber auch die Eignung als Nisthabitat, insbesondere der Ackerrandstrukturen. Viele der Ackerwildkrautschutzflächen weisen zudem einen Biotopverbund mit anderen wertvollen Wildbienenlebensräumen wie Magerrasen auf. Auch der Einfluss der Einbettung in eine strukturreiche Agrarlandschaft mit extensiv bewirtschafteten, mageren Grünländern ist Teil der Untersuchung.

Kontakt:
Dr. Annika Hass
Funktionelle Agrobiodiversität Tel.: 0551 / 39-22157
Email: ahass@gwdg.de