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Neacă AM, Meis J, Knight T, Rakosy D. Intensive pasture management alters the composition and structure of plant-pollinator interactions in Sibiu, Romania. PeerJ 2024; 12:e16900. [PMID: 38435994 PMCID: PMC10909354 DOI: 10.7717/peerj.16900] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/03/2023] [Accepted: 01/16/2024] [Indexed: 03/05/2024] Open
Abstract
Background Land management change towards intensive grazing has been shown to alter plant and pollinator communities and the structure of plant-pollinator interactions in different ways across the world. Land-use intensification in Eastern Europe is shifting highly diverse, traditionally managed hay meadows towards intensive pastures, but few studies have examined how this influences plant-pollinator networks. We hypothesized that the effects of intensive grazing on networks will depend on how plant communities and their floral traits change. Methods We investigated plant and pollinator diversity and composition and the structure of plant-pollinator interactions near Sibiu, Romania at sites that were traditionally managed as hay meadows or intensive pastures. We quantified the identity and abundance of flowering plants, and used transect walks to observe pollinator genera interacting with flowering plant species. We evaluated the effects of management on diversity, composition and several indices of network structure. Results Pollinator but not plant diversity declined in pastures and both plant and pollinator taxonomic composition shifted. Functional diversity and composition remained unchanged, with rather specialized flowers having been found to dominate in both hay meadows and pastures. Apis mellifera was found to be the most abundant pollinator. Its foraging preferences played a crucial role in shaping plant-pollinator network structure. Apis mellifera thus preferred the highly abundant Dorycnium herbaceum in hay meadows, leading to hay meadows networks with lower Shannon diversity and interaction evenness. In pastures, however, it preferred less abundant and more generalized flower resources. With pollinators being overall less abundant and more generalized in pastures, we found that niche overlap between plants was higher. Discussion With both hay meadows and pastures being dominated by plant species with similar floral traits, shifts in pollinator preferences seem to have driven the observed changes in plant-pollinator interaction networks. We thus conclude that the effects of grazing on pollinators and their interactions are likely to depend on the traits of plant species present in different management types as well as on the effects of grazing on plant community composition. We thereby highlight the need for better understanding how floral abundance shapes pollinator visitation rates and how floral traits may influence this relationship.
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Affiliation(s)
- Ana-Maria Neacă
- Faculty of Biology and Geology, Babeș-Bolyai University, Cluj-Napoca, Romania
| | - Julia Meis
- Institute of Biology, Martin Luther University Halle-Wittenberg, Halle, Germany
- Helmholtz Centre for Environmental Research–UFZ, Leipzig, Germany
| | - Tiffany Knight
- Institute of Biology, Martin Luther University Halle-Wittenberg, Halle, Germany
- Department Species Interaction Ecology, German Centre for Integrative Biodiversity Research (iDiv) Halle-Jena-Leipzig, Leipzig, Germany
- Department Species Interaction Ecology, Helmholtz Centre for Environmental Research–UFZ, Leipzig, Germany
| | - Demetra Rakosy
- Department Species Interaction Ecology, German Centre for Integrative Biodiversity Research (iDiv) Halle-Jena-Leipzig, Leipzig, Germany
- Department Species Interaction Ecology, Helmholtz Centre for Environmental Research–UFZ, Leipzig, Germany
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Ronca S, Ford CS, Allanguillaume J, Szabo C, Kipling R, Wilkinson MJ. The value of twinned pollinator-pollen metabarcoding: bumblebee pollination service is weakly partitioned within a UK grassland community. Sci Rep 2023; 13:18016. [PMID: 37865658 PMCID: PMC10590402 DOI: 10.1038/s41598-023-44822-z] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/11/2022] [Accepted: 10/12/2023] [Indexed: 10/23/2023] Open
Abstract
Predicting ecological impact of declining bumblebee (Bombus) populations requires better understanding of interactions between pollinator partitioning of floral resources and plant partitioning of pollinator resources. Here, we combine Cytochrome Oxidase 1 (CO1) barcoding for bumblebee identification and rbcL metabarcoding of pollen carried by bees in three species-rich UK pastures. CO1 barcoding assigned 272 bees to eight species, with 33 individuals belonging to the cryptic Bombus lucorum complex (16 B. lucorum and 17 B. cryptarum). Seasonal bias in capture rates varied by species, with B. pratorum found exclusively in June/July and B. pascuorum more abundant in August. Pollen metabarcoding coupled with PERMANOVA and NMDS analyses revealed all bees carried several local pollen species and evidence of pollen resource partitioning between some species pairings, with Bombus pratorum carrying the most divergent pollen load. There was no evidence of resource partitioning between the two cryptic species present, but significantly divergent capture rates concorded with previous suggestions of separation on the basis of foraging behaviour being shaped by local/temporal differences in climatic conditions. Considering the bee carriage profile of pollen species revealed no significant difference between the nine most widely carried plant species. However, there was a sharp, tipping point change in community pollen carriage across all three sites that occurred during the transition between late July and early August. This transition resulted in a strong divergence in community pollen carriage between the two seasonal periods in both years. We conclude that the combined use of pollen and bee barcoding offers several benefits for further study of plant-pollinator interactions at the landscape scale.
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Affiliation(s)
- Sandra Ronca
- Department of Life Sciences, Aberystwyth University, Aberystwyth, SY23 3DA, UK
| | - Caroline S Ford
- Wales Veterinary Science Centre, Y Buarth, Aberystwyth, SY23 1ND, Ceredigion, UK
| | - Joël Allanguillaume
- Department of Biological, Biomedical and Analytical Sciences, University of the West of England, Coldharbour Lane, Bristol, BS16 1QY, UK
| | - Claudia Szabo
- School of Computer Science, The University of Adelaide, Adelaide, SA, 5005, Australia
| | - Richard Kipling
- The Sustainable Food Trust, 38 Richmond Street, Totterdown, Bristol, BS3 4TQ, UK
| | - Mike J Wilkinson
- Department of Life Sciences, Aberystwyth University, Aberystwyth, SY23 3DA, UK.
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Rakosy D, Motivans E, Ştefan V, Nowak A, Świerszcz S, Feldmann R, Kühn E, Geppert C, Venkataraman N, Sobieraj-Betlińska A, Grossmann A, Rojek W, Pochrząst K, Cielniak M, Gathof AK, Baumann K, Knight TM. Intensive grazing alters the diversity, composition and structure of plant-pollinator interaction networks in Central European grasslands. PLoS One 2022; 17:e0263576. [PMID: 35275933 PMCID: PMC8916670 DOI: 10.1371/journal.pone.0263576] [Citation(s) in RCA: 2] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/30/2021] [Accepted: 01/21/2022] [Indexed: 11/28/2022] Open
Abstract
Complex socio-economic, political and demographic factors have driven the increased conversion of Europe's semi-natural grasslands to intensive pastures. This trend is particularly strong in some of the most biodiverse regions of the continent, such as Central and Eastern Europe. Intensive grazing is known to decrease species diversity and alter the composition of plant and insect communities. Comparatively little is known, however, about how intensive grazing influences plant functional traits related to pollination and the structure of plant-pollinator interactions. In traditional hay meadows and intensive pastures in Central Europe, we contrasted the taxonomic and functional group diversity and composition, the structure of plant-pollinator interactions and the roles of individual species in networks. We found mostly lower taxonomic and functional diversity of plants and insects in intensive pastures, as well as strong compositional differences among the two grassland management types. Intensive pastures were dominated by a single plant with a specialized flower structure that is only accessible to a few pollinator groups. As a result, intensive pastures have lower diversity and specificity of interactions, higher amount of resource overlap, more uniform interaction strength and lower network modularity. These findings stand in contrast to studies in which plants with more generalized flower traits dominated pastures. Our results thus highlight the importance of the functional traits of dominant species in mediating the consequences of intensive pasture management on plant-pollinator networks. These findings could further contribute to strategies aimed at mitigating the impact of intensive grazing on plant and pollinator communities.
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Affiliation(s)
- Demetra Rakosy
- Department for Community Ecology, Helmholtz Centre for Environmental Research–UFZ, Leipzig, Germany
- German Centre for Integrative Biodiversity Research (iDiv) Halle-Jena-Leipzig, Leipzig, Germany
| | - Elena Motivans
- Department for Community Ecology, Helmholtz Centre for Environmental Research–UFZ, Leipzig, Germany
- German Centre for Integrative Biodiversity Research (iDiv) Halle-Jena-Leipzig, Leipzig, Germany
- Institute of Biology, Martin Luther University Halle-Wittenberg, Halle (Saale), Germany
| | - Valentin Ştefan
- German Centre for Integrative Biodiversity Research (iDiv) Halle-Jena-Leipzig, Leipzig, Germany
- Institute of Biology, Martin Luther University Halle-Wittenberg, Halle (Saale), Germany
| | - Arkadiusz Nowak
- Center for Biological Diversity Conservation, Polish Academy of Sciences, Botanical Garden, Warsaw, Poland
- Institute of Biology, University of Opole, Opole, Poland
| | - Sebastian Świerszcz
- Center for Biological Diversity Conservation, Polish Academy of Sciences, Botanical Garden, Warsaw, Poland
- Polish Academy of Sciences, The Franciszek Górski Institute of Plant Physiology, Opole, Poland
| | - Reinart Feldmann
- Department for Community Ecology, Helmholtz Centre for Environmental Research–UFZ, Leipzig, Germany
- Helmholtz Centre for Environmental Research–UFZ, Leipzig, Germany
| | - Elisabeth Kühn
- Department for Community Ecology, Helmholtz Centre for Environmental Research–UFZ, Leipzig, Germany
| | - Costanza Geppert
- Department of Agronomy, Food, Natural Resources, Animals and Environment, University of Padova School of Agricultural Sciences and Veterinary Medicine, Padova, Italy
| | - Neeraja Venkataraman
- German Centre for Integrative Biodiversity Research (iDiv) Halle-Jena-Leipzig, Leipzig, Germany
- Institute of Biology, Martin Luther University Halle-Wittenberg, Halle (Saale), Germany
| | - Anna Sobieraj-Betlińska
- Department of Environmental Biology, Faculty of Biological Sciences, Kazimierz Wielki University, Bydgoszcz, Poland
| | - Anita Grossmann
- Department of Ecology, Chair of Ecosystem Sciences/Plant Ecology, Technical University Berlin, Berlin, Germany
| | - Wiktoria Rojek
- Institute of Environmental Sciences, Jagiellonian University, Krakow, Poland
| | - Katarzyna Pochrząst
- Faculty of Natural Sciences and Technology, University of Opole, Opole, Poland
| | | | - Anika Kirstin Gathof
- Department of Ecology, Chair of Ecosystem Sciences/Plant Ecology, Technical University Berlin, Berlin, Germany
| | - Kevin Baumann
- IFZ–Department for Animal Ecology, Justus Liebig University, Gießen, Germany
| | - Tiffany Marie Knight
- Department for Community Ecology, Helmholtz Centre for Environmental Research–UFZ, Leipzig, Germany
- German Centre for Integrative Biodiversity Research (iDiv) Halle-Jena-Leipzig, Leipzig, Germany
- Institute of Biology, Martin Luther University Halle-Wittenberg, Halle (Saale), Germany
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