Press release: Visiting flowers and transporting pollen in fragmented landscapes
No. 83 - 29.05.2024
Research team compares wild bee networks at a small scale and at landscape level
Traditionally, interactions between plants and their pollinators are analysed on the basis of visits to flowers. A research team led by the University of Göttingen studied wild bees on chalk grassland. The researchers analysed both the networks showing visits to flowers and the networks where pollen was transported. They found that the visits by bees to flowers were not always associated with pollen collection. The data about pollen also clearly showed that the number of interactions, which could only be found on individual patches of chalk grasslands, increased with greater landscape diversity. Their findings showed that researchers underestimate the degree of specialisation of networks if they only study the landscapes without data on pollen transport. The results were published in the journal Proceedings of the Royal Society B.
Understanding the organisation of networks between plants and their pollinators is vital for supporting nature conservation when planning landscapes. However, little is known about how the networks between pollen and bees are influenced by changes at the landscape level. Combining data from 29 small, fragmented patches of chalk grassland, which are among the most species-rich habitats in Central Europe, showed that 37 per cent of interactions between individual plant and wild bee species occurred in both pollen transport and flower-visiting networks. Twenty-eight per cent of the interactions could only be detected in pollen transport networks and 35 per cent only in flower-visiting networks. When all local networks are analysed together, the pollen transport data show that the proportion of interactions unique to each patch of chalk grassland increased with landscape diversity.
"Our results show that the specialization of plant-pollinator networks decreases in diverse landscapes. If just information about visits to flowers is analysed, it doesn’t provide the full picture and underestimates the plant-pollinator specialisation," explains Dr Felipe Librán-Embid, who carried out the research as part of his PhD in Agroecology at the Faculty of Agricultural Sciences in Göttingen. "Data on pollen transport and also the analysis of meta-networks – taking into account all the different networks – are both fundamental for understanding and managing pollinators and the plants they visit in cultivated landscapes," adds Professor Teja Tscharntke from Göttingen University, who supervised the work together with Professor Ingo Grass from the University of Hohenheim.
Original publication: Felipe Librán-Embid et al. (2024). Flower-bee vs pollen-bee metanetworks in fragmented landscapes. Proceedings of the Royal Society London B. DoI: 10.1098/rspb.2023.2604
Contact:
Dr Felipe Librán-Embid
Justus Liebig University Giessen
Department of Animal Ecology & Systematics
Heinrich-Buff-Ring 26, 35392 Giessen, Germany
Email: Felipe.Libran-Embid@allzool.biol.uni-giessen.de
Professor Teja Tscharntke
University of Göttingen
Faculty of Agricultural Sciences – Agroecology Research Group
Grisebachstraße 6, 37077 Göttingen, Germany
Tel: +49 (0)551 / 39-29209, Email: ttschar@gwdg.de