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Bosco L, Yañez O, Schauer A, Maurer C, Cushman SA, Arlettaz R, Jacot A, Seuberlich T, Neumann P, Schläppi D. Landscape structure affects temporal dynamics in the bumble bee virome: Landscape heterogeneity supports colony resilience. THE SCIENCE OF THE TOTAL ENVIRONMENT 2024; 946:174280. [PMID: 38942311 DOI: 10.1016/j.scitotenv.2024.174280] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 01/14/2024] [Revised: 06/23/2024] [Accepted: 06/23/2024] [Indexed: 06/30/2024]
Abstract
Virus spillovers from managed honey bees, Apis mellifera, are thought to contribute to the decline of wild pollinators, including bumble bees. However, data on the impact of such viruses on wild pollinators remain scarce, and the influence of landscape structure on virus dynamics is poorly understood. In this study, we deployed bumble bee colonies in an agricultural landscape and studied changes in the bumble bee virome during field placement under varying habitat composition and configuration using a multiscale analytical framework. We estimated prevalence of viruses and viral loads (i.e. number of viral genomic equivalent copies) in bumble bees before and after placing them in the field using next generation sequencing and quantitative PCR. The results show that viral loads and number of different viruses present increased during placement in the field and that the virus composition of the colonies shifted from an initial dominance of honey bee associated viruses to a higher number (in both viral loads and number of viruses present) of bumble bee associated viruses. Especially DWV-B, typical for honey bees, drastically decreased after the time in the field. Viral loads prior to placing colonies in the field showed no effect on colony development, suggesting low impacts of these viruses in field settings. Notably, we further demonstrate that increased habitat diversity results in a lower number of different viruses present in Bombus colonies, while colonies in areas with well-connected farmland patches decreased in their total viral load after field placement. Our results emphasize the importance of landscape heterogeneity and connectivity for wild pollinator health and that these influences predominate at fine spatial scales.
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Affiliation(s)
- Laura Bosco
- LUOMUS - Finnish Museum of Natural History, PL 17 - P.O. Box 17, 00014, University of Helsinki, Finland; Division of Conservation Biology, Institute of Ecology and Evolution, University of Bern, Baltzerstrasse 6, 3012 Bern, Switzerland.
| | - Orlando Yañez
- Institute of Bee Health, Vetsuisse Faculty, University of Bern, Schwarzenburgstrasse 161, 3003 Bern, Switzerland.
| | - Alexandria Schauer
- Institute of Bee Health, Vetsuisse Faculty, University of Bern, Schwarzenburgstrasse 161, 3003 Bern, Switzerland.
| | - Corina Maurer
- Division of Conservation Biology, Institute of Ecology and Evolution, University of Bern, Baltzerstrasse 6, 3012 Bern, Switzerland; Agroecology and Environment, Agroscope, Reckenholzstrasse 191, 8046 Zürich, Switzerland; Ecosystems Landscape Evolution, Institute of Terrestrial Ecosystems, Department of Environmental Systems Science, ETH Zürich, 8092 Zürich, Switzerland.
| | - Samuel A Cushman
- Wildlife Conservation Research Unit, Department of Biology, University of Oxford, Oxford, United Kingdom
| | - Raphaël Arlettaz
- Division of Conservation Biology, Institute of Ecology and Evolution, University of Bern, Baltzerstrasse 6, 3012 Bern, Switzerland.
| | - Alain Jacot
- Division of Conservation Biology, Institute of Ecology and Evolution, University of Bern, Baltzerstrasse 6, 3012 Bern, Switzerland; Swiss Ornithological Institute, Regional Office Valais, 1950 Sion, Switzerland.
| | - Torsten Seuberlich
- Division of Neurological Sciences, University of Bern, Bern, Switzerland.
| | - Peter Neumann
- Institute of Bee Health, Vetsuisse Faculty, University of Bern, Schwarzenburgstrasse 161, 3003 Bern, Switzerland.
| | - Daniel Schläppi
- Institute of Bee Health, Vetsuisse Faculty, University of Bern, Schwarzenburgstrasse 161, 3003 Bern, Switzerland; School of Biological Sciences, University of Bristol, Life Science Building, 24 Tyndall Avenue, BS8 1TQ Bristol, United Kingdom.
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2
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Hederström V, Ekroos J, Friberg M, Krausl T, Opedal ØH, Persson AS, Petrén H, Quan Y, Smith HG, Clough Y. Pollinator-mediated effects of landscape-scale land use on grassland plant community composition and ecosystem functioning - seven hypotheses. Biol Rev Camb Philos Soc 2024; 99:675-698. [PMID: 38118437 DOI: 10.1111/brv.13040] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/29/2022] [Revised: 12/05/2023] [Accepted: 12/07/2023] [Indexed: 12/22/2023]
Abstract
Environmental change is disrupting mutualisms between organisms worldwide. Reported declines in insect populations and changes in pollinator community compositions in response to land use and other environmental drivers have put the spotlight on the need to conserve pollinators. While this is often motivated by their role in supporting crop yields, the role of pollinators for reproduction and resulting taxonomic and functional assembly in wild plant communities has received less attention. Recent findings suggest that observed and experimental gradients in pollinator availability can affect plant community composition, but we know little about when such shifts are to be expected, or the impact they have on ecosystem functioning. Correlations between plant traits related to pollination and plant traits related to other important ecosystem functions, such as productivity, nitrogen uptake or palatability to herbivores, lead us to expect non-random shifts in ecosystem functioning in response to changes in pollinator communities. At the same time, ecological and evolutionary processes may counteract these effects of pollinator declines, limiting changes in plant community composition, and in ecosystem functioning. Despite calls to investigate community- and ecosystem-level impacts of reduced pollination, the study of pollinator effects on plants has largely been confined to impacts on plant individuals or single-species populations. With this review we aim to break new ground by bringing together aspects of landscape ecology, ecological and evolutionary plant-insect interactions, and biodiversity-ecosystem functioning research, to generate new ideas and hypotheses about the ecosystem-level consequences of pollinator declines in response to land-use change, using grasslands as a focal system. Based on an integrated set of seven hypotheses, we call for more research investigating the putative pollinator-mediated links between landscape-scale land use and ecosystem functioning. In particular, future research should use combinations of experimental and observational approaches to assess the effects of changes in pollinator communities over multiple years and across species on plant communities and on trait distributions both within and among species.
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Affiliation(s)
- Veronica Hederström
- Centre for Environmental and Climate Science, Lund University, Sölvegatan 37, Lund, 223 62, Sweden
| | - Johan Ekroos
- Centre for Environmental and Climate Science, Lund University, Sölvegatan 37, Lund, 223 62, Sweden
| | - Magne Friberg
- Department of Biology, Lund University, Sölvegatan 37, Lund, 223 62, Sweden
| | - Theresia Krausl
- Centre for Environmental and Climate Science, Lund University, Sölvegatan 37, Lund, 223 62, Sweden
| | - Øystein H Opedal
- Department of Biology, Lund University, Sölvegatan 37, Lund, 223 62, Sweden
| | - Anna S Persson
- Centre for Environmental and Climate Science, Lund University, Sölvegatan 37, Lund, 223 62, Sweden
| | - Hampus Petrén
- Department of Biology, Lund University, Sölvegatan 37, Lund, 223 62, Sweden
| | - Yuanyuan Quan
- Centre for Environmental and Climate Science, Lund University, Sölvegatan 37, Lund, 223 62, Sweden
| | - Henrik G Smith
- Centre for Environmental and Climate Science, Lund University, Sölvegatan 37, Lund, 223 62, Sweden
- Department of Biology, Lund University, Sölvegatan 37, Lund, 223 62, Sweden
| | - Yann Clough
- Centre for Environmental and Climate Science, Lund University, Sölvegatan 37, Lund, 223 62, Sweden
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Tourbez C, Gómez-Martínez C, González-Estévez MÁ, Lázaro A. Pollen analysis reveals the effects of uncovered interactions, pollen-carrying structures, and pollinator sex on the structure of wild bee-plant networks. INSECT SCIENCE 2024; 31:971-988. [PMID: 37681316 DOI: 10.1111/1744-7917.13267] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 02/08/2023] [Revised: 07/11/2023] [Accepted: 07/31/2023] [Indexed: 09/09/2023]
Abstract
Pollination networks are increasingly used to model the complexity of interactions between pollinators and flowering plants in communities. Different methods exist to sample these interactions, with direct observations of plant-pollinator contacts in the field being by far the most common. Although the identification of pollen carried by pollinators allows uncovering interactions and increasing sample sizes, the methods used to build pollen-transport networks are variable and their effect on network structure remains unclear. To understand how interaction sampling influences the structure of networks, we analyzed the pollen found on wild bees from eight communities across Mallorca Island and investigated the differences in pollen loads between bee body parts (scopa vs. body) and sexes. We then assessed how these differences, as well as the uncovered interactions not detected in the field, influenced the structure of wild bee-plant networks. We identified a higher quantity and diversity of pollen in the scopa than in the rest of the female body, but these differences did not lead to differences in structure between plant-pollination (excluding scopa pollen) and bee-feeding interaction (including scopa pollen) networks. However, networks built with pollen data were richer in plant species and interactions and showed lower modularity and specialization (H2'), and higher nestedness than visitation networks based on field observations. Female interactions with plants were stronger compared to those of males, although not richer. Accordingly, females were more generalist (low d') and tended to be more central in interaction networks, indicating their more key role structuring pollination networks in comparison to males. Our study highlights the importance of palynological data to increase the resolution of networks, as well as to understand important ecological questions such as the differences between plant-pollination and bee-feeding interaction networks, and the role of sexes in pollination.
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Affiliation(s)
- Clément Tourbez
- Mediterranean Institute for Advanced Studies (UIB-CSIC), Global Change Research Group, Esporles, Balearic Islands, Spain
| | - Carmelo Gómez-Martínez
- Mediterranean Institute for Advanced Studies (UIB-CSIC), Global Change Research Group, Esporles, Balearic Islands, Spain
| | - Miguel Ángel González-Estévez
- Mediterranean Institute for Advanced Studies (UIB-CSIC), Global Change Research Group, Esporles, Balearic Islands, Spain
| | - Amparo Lázaro
- Mediterranean Institute for Advanced Studies (UIB-CSIC), Global Change Research Group, Esporles, Balearic Islands, Spain
- Department of Biology, Ecology Area, University of the Balearic Islands, Palma, Spain
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Gómez‐Martínez C, González‐Estévez MA, Cursach J, Lázaro A. Pollinator richness, pollination networks, and diet adjustment along local and landscape gradients of resource diversity. ECOLOGICAL APPLICATIONS : A PUBLICATION OF THE ECOLOGICAL SOCIETY OF AMERICA 2022; 32:e2634. [PMID: 35403772 PMCID: PMC9539497 DOI: 10.1002/eap.2634] [Citation(s) in RCA: 4] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Received: 11/30/2021] [Revised: 02/06/2022] [Accepted: 02/18/2022] [Indexed: 06/14/2023]
Abstract
Loss of habitats and native species, introduction of invasive species, and changing climate regimes lead to the homogenization of landscapes and communities, affecting the availability of habitats and resources for economically important guilds, such as pollinators. Understanding how pollinators and their interactions vary along resource diversity gradients at different scales may help to determine their adaptability to the current diversity loss related to global change. We used data on 20 plant-pollinator communities along gradients of flower richness (local diversity) and landscape heterogeneity (landscape diversity) to understand how the diversity of resources at local and landscape scales affected (1) wild pollinator abundance and richness (accounting also for honey bee abundance), (2) the structure of plant-pollinator networks, (3) the proportion of actively selected interactions (those not occurring by neutral processes), and (4) pollinator diet breadth and species' specialization in networks. Wild pollinator abundance was higher overall in flower-rich and heterogeneous habitats, while wild pollinator richness increased with flower richness (more strongly for beetles and wild bees) and decreased with honeybee abundance. Network specialization (H2 '), modularity, and functional complementarity were all positively related to floral richness and landscape heterogeneity, indicating niche segregation as the diversity of resources increases at both scales. Flower richness also increased the proportion of actively selected interactions (especially for wild bees and flies), whereas landscape heterogeneity had a weak negative effect on this variable. Overall, network-level metrics responded to larger landscape scales than pollinator-level metrics did. Higher floral richness resulted in a wider taxonomic and functional diet for all the study guilds, while functional diet increased mainly for beetles. Despite this, specialization in networks (d') increased with flower richness for all the study guilds, because pollinator species fed on a narrower subset of plants as communities became richer in species. Our study indicates that pollinators are able to adapt their diet to resource changes at local and landscape scales. However, resource homogenization might lead to poor and generalist pollinator communities, where functionally specialized interactions are lost. This study highlights the importance of including different scales to understand the effects of global change on pollination service through changes in resource diversity.
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Affiliation(s)
- Carmelo Gómez‐Martínez
- Global Change Research GroupMediterranean Institute for Advanced Studies (UIB‐CSIC)EsporlesSpain
| | | | - Joana Cursach
- Department of Biology, Laboratory of Botany, Research Group on Plant Biology under Mediterranean ConditionsUniversity of the Balearic IslandsPalmaSpain
| | - Amparo Lázaro
- Global Change Research GroupMediterranean Institute for Advanced Studies (UIB‐CSIC)EsporlesSpain
- Department of Biology, Ecology AreaUniversity of the Balearic IslandsPalmaSpain
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5
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Lázaro A, Gómez‐Martínez C. Habitat loss increases seasonal interaction rewiring in plant‐pollinator networks. Funct Ecol 2022. [DOI: 10.1111/1365-2435.14160] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
Affiliation(s)
- Amparo Lázaro
- Mediterranean Institute for Advanced Studies (IMEDEA; UIB‐CSIC). Global Change Research Group. C/ Miquel Marquès 21 Esporles Balearic Islands Spain
| | - Carmelo Gómez‐Martínez
- Mediterranean Institute for Advanced Studies (IMEDEA; UIB‐CSIC). Global Change Research Group. C/ Miquel Marquès 21 Esporles Balearic Islands Spain
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