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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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2
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Stenhouse EH, Bellamy P, Kirby W, Vaughan IP, Drake LE, Marchbank A, Workman T, Symondson WOC, Orozco‐terWengel P. Multi-marker DNA metabarcoding reveals spatial and sexual variation in the diet of a scarce woodland bird. Ecol Evol 2023; 13:e10089. [PMID: 37206688 PMCID: PMC10191781 DOI: 10.1002/ece3.10089] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/21/2023] [Revised: 04/24/2023] [Accepted: 04/28/2023] [Indexed: 05/21/2023] Open
Abstract
Avian diet can be affected by site-specific variables, such as habitat, as well as intrinsic factors such as sex. This can lead to dietary niche separation, which reduces competition between individuals, as well as impacting how well avian species can adapt to environmental variation. Estimating dietary niche separation is challenging, due largely to difficulties in accurately identifying food taxa consumed. Consequently, there is limited knowledge of the diets of woodland bird species, many of which are undergoing serious population declines. Here, we show the effectiveness of multi-marker fecal metabarcoding to provide in-depth dietary analysis of a declining passerine in the UK, the Hawfinch (Coccothraustes coccothraustes). We collected fecal samples from (n = 262) UK Hawfinches prior to, and during, the breeding seasons in 2016-2019. We detected 49 and 90 plant and invertebrate taxa, respectively. We found Hawfinch diet varied spatially, as well as between sexes, indicating broad dietary plasticity and the ability of Hawfinches to utilize multiple resources within their foraging environments.
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Affiliation(s)
- Ewan H. Stenhouse
- School of BiosciencesCardiff UniversityCardiffUK
- RSPB Centre for Conservation Science, The LodgeSandyUK
| | - Paul Bellamy
- RSPB Centre for Conservation Science, The LodgeSandyUK
| | - Will Kirby
- RSPB Centre for Conservation Science, The LodgeSandyUK
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3
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The degree of urbanisation reduces wild bee and butterfly diversity and alters the patterns of flower-visitation in urban dry grasslands. Sci Rep 2023; 13:2702. [PMID: 36792660 PMCID: PMC9932066 DOI: 10.1038/s41598-023-29275-8] [Citation(s) in RCA: 3] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/29/2022] [Accepted: 02/01/2023] [Indexed: 02/17/2023] Open
Abstract
Insect-provided pollination services are increasingly threatened due to alarming declines in insect pollinator populations. One of the main threats to insect pollinators and consequently pollination is urbanisation. Here, we investigate the effects of local habitat quality (patch size, flowering plant richness, bare soil cover, vegetation structure), degree of urbanisation (impervious surfaces) and 3D connectivity on bee, hoverfly and butterfly flower visitors and plant-flower visitor networks in flower-rich urban dry grasslands. Overall, the degree of urbanisation and the quality of the local habitat influenced the flowering plant and pollinator communities. Although flowering plant abundance increased with urbanisation, bee species richness and butterfly species richness decreased with increasing impervious surfaces. Flowering plant richness and ground nesting resource availability were positively related to bee richness and local vegetation structure boosted hoverfly and butterfly visitation rates. In terms of plant-pollinator interactions, insect pollinators visited a lower proportion of the available flowering plants in more urbanised areas and network modularity and specialisation increased with patch size. Our findings show that urban dry grasslands are valuable habitats for species-rich pollinator communities and further highlight the importance of minimizing the intensity of urbanisation and the potential of local management practices to support insect biodiversity in cities.
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Llopis-Belenguer C, Balbuena JA, Blasco-Costa I, Karvonen A, Sarabeev V, Jokela J. Sensitivity of bipartite network analyses to incomplete sampling and taxonomic uncertainty. Ecology 2023; 104:e3974. [PMID: 36691292 DOI: 10.1002/ecy.3974] [Citation(s) in RCA: 1] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 06/29/2022] [Revised: 11/22/2022] [Accepted: 11/29/2022] [Indexed: 01/25/2023]
Abstract
Bipartite network analysis is a powerful tool to study the processes structuring interactions in ecological communities. In applying the method, it is assumed that the sampled interactions provide an accurate representation of the actual community. However, acquiring a representative sample may be difficult as not all species are equally abundant or easily identifiable. Two potential sampling issues can compromise the conclusions of bipartite network analyses: failure to capture the full range of interactions (sampling completeness) and use of a taxonomic level higher than species to evaluate the network (taxonomic resolution). We asked how commonly used descriptors of bipartite antagonistic communities (modularity, nestedness, connectance, and specialization [H2 ']) are affected by reduced host sampling completeness, parasite taxonomic resolution, and their crossed effect, as they are likely to co-occur. We used a quantitative niche model to generate weighted bipartite networks that resembled natural host-parasite communities. The descriptors were more sensitive to uncertainty in parasite taxonomic resolution than to host sampling completeness. When only 10% of parasite taxonomic resolution was retained, modularity and specialization decreased by ~76% and ~12%, respectively, and nestedness and connectance increased by ~114% and ~345% respectively. The loss of taxonomic resolution led to a wide range of possible communities, which made it difficult to predict its effects on a given network. With regards to host sampling completeness, standardized nestedness, connectance, and specialization were robust, whereas modularity was sensitive (~30% decrease). The combination of both sampling issues had an additive effect on modularity. In communities with low effort for both sampling issues (50%-10% of sampling completeness and taxonomic resolution), estimators of modularity, and nestedness could not be distinguished from those of random assemblages. Thus, the categorical description of communities with low sampling effort (e.g., if a community is modular or not) should be done with caution. We recommend evaluating both sampling completeness and taxonomic certainty when conducting bipartite network analyses. Care should also be exercised when using nonrobust descriptors (the four descriptors for parasite taxonomic resolution; modularity for host sampling completeness) when sampling issues are likely to affect a dataset.
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Affiliation(s)
- Cristina Llopis-Belenguer
- Institute of Integrative Biology, D-USYS, ETH Zürich, Zürich, Switzerland.,Department of Aquatic Ecology, EAWAG, Dübendorf, Switzerland
| | - Juan Antonio Balbuena
- Cavanilles Institute of Biodiversity and Evolutionary Biology, University of Valencia, Valencia, Spain
| | - Isabel Blasco-Costa
- Department of Invertebrates, Natural History Museum of Geneva, Geneva, Switzerland.,Department of Arctic and Marine Biology, UiT The Arctic University of Norway, Tromsø, Norway
| | - Anssi Karvonen
- Department of Biological and Environmental Science, University of Jyväskylä, Jyväskylä, Finland
| | - Volodimir Sarabeev
- Department of Biology, Zaporizhzhia National University, Zaporizhzhia, Ukraine.,Institute of Parasitology, Slovak Academy of Sciences, Košice, Slovak Republic
| | - Jukka Jokela
- Institute of Integrative Biology, D-USYS, ETH Zürich, Zürich, Switzerland.,Department of Aquatic Ecology, EAWAG, Dübendorf, Switzerland
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5
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Prendergast KS, Ollerton J. Impacts of the introduced European honeybee on Australian bee‐flower network properties in urban bushland remnants and residential gardens. AUSTRAL ECOL 2021. [DOI: 10.1111/aec.13040] [Citation(s) in RCA: 7] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/26/2022]
Affiliation(s)
- Kit S. Prendergast
- School of Molecular and Life Sciences Curtin University Perth, Bentley Western Australia 6845 Australia
| | - Jeff Ollerton
- Faculty of Arts, Science and Technology University of Northampton Northampton UK
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Doré M, Fontaine C, Thébault E. Relative effects of anthropogenic pressures, climate, and sampling design on the structure of pollination networks at the global scale. GLOBAL CHANGE BIOLOGY 2021; 27:1266-1280. [PMID: 33274540 DOI: 10.1111/gcb.15474] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 09/08/2020] [Accepted: 10/10/2020] [Indexed: 06/12/2023]
Abstract
Pollinators provide crucial ecosystem services that underpin to wild plant reproduction and yields of insect-pollinated crops. Understanding the relative impacts of anthropogenic pressures and climate on the structure of plant-pollinator interaction networks is vital considering ongoing global change and pollinator decline. Our ability to predict the consequences of global change for pollinator assemblages worldwide requires global syntheses, but these analytical approaches may be hindered by variable methods among studies that either invalidate comparisons or mask biological phenomena. Here we conducted a synthetic analysis that assesses the relative impact of anthropogenic pressures and climatic variability, and accounts for heterogeneity in sampling methodology to reveal network responses at the global scale. We analyzed an extensive dataset, comprising 295 networks over 123 locations all over the world, and reporting over 50,000 interactions between flowering plant species and their insect visitors. Our study revealed that anthropogenic pressures correlate with an increase in generalism in pollination networks while pollinator richness and taxonomic composition are more related to climatic variables with an increase in dipteran pollinator richness associated with cooler temperatures. The contrasting response of species richness and generalism of the plant-pollinator networks stresses the importance of considering interaction network structure alongside diversity in ecological monitoring. In addition, differences in sampling design explained more variation than anthropogenic pressures or climate on both pollination networks richness and generalism, highlighting the crucial need to report and incorporate sampling design in macroecological comparative studies of pollination networks. As a whole, our study reveals a potential human impact on pollination networks at a global scale. However, further research is needed to evaluate potential consequences of loss of specialist species and their unique ecological interactions and evolutionary pathways on the ecosystem pollination function at a global scale.
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Affiliation(s)
- Maël Doré
- Institut de Systématique, Evolution, Biodiversité, MNHN-CNRS-Sorbonne Université-EPHE-Université des Antilles, Muséum national d'Histoire naturelle de Paris, Paris, France
- Centre d'Ecologie et des Sciences de la Conservation, UMR 7204 MNHN-CNRS-Sorbonne Université, Muséum national d'Histoire naturelle de Paris, Paris, France
- Sorbonne Université, CNRS, IRD, INRAE, Université Paris Est Créteil, Institute of Ecology and Environmental Sciences of Paris (iEES-Paris), Paris, France
| | - Colin Fontaine
- Centre d'Ecologie et des Sciences de la Conservation, UMR 7204 MNHN-CNRS-Sorbonne Université, Muséum national d'Histoire naturelle de Paris, Paris, France
| | - Elisa Thébault
- Sorbonne Université, CNRS, IRD, INRAE, Université Paris Est Créteil, Institute of Ecology and Environmental Sciences of Paris (iEES-Paris), Paris, France
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7
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Plant-pollinator networks in Australian urban bushland remnants are not structurally equivalent to those in residential gardens. Urban Ecosyst 2021. [DOI: 10.1007/s11252-020-01089-w] [Citation(s) in RCA: 11] [Impact Index Per Article: 3.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/22/2022]
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da Silva LP, Mata VA, Lopes PB, Lopes RJ, Beja P. High-resolution multi-marker DNA metabarcoding reveals sexual dietary differentiation in a bird with minor dimorphism. Ecol Evol 2020; 10:10364-10373. [PMID: 33072265 PMCID: PMC7548197 DOI: 10.1002/ece3.6687] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/21/2020] [Revised: 07/25/2020] [Accepted: 07/28/2020] [Indexed: 11/11/2022] Open
Abstract
Although sexual dietary differentiation is well known in birds, it is usually linked with significant morphological dimorphism between males and females, with lower differentiation reported in sexually monomorphic or only slightly dimorphic species. However, this may be an artifact of poor taxonomic resolution achieved in most conventional dietary studies, which may be unable to detect subtle intraspecific differentiation in prey consumption. Here, we show the power of multi‐marker metabarcoding to address these issues, focusing on a slightly dimorphic generalist passerine, the black wheatear Oenanthe leucura. Using markers from four genomic regions (18S, 16S, COI, and trnL), we analyzed fecal droppings collected from 93 adult black wheatears during the breeding season. We found that sexes were rather similar in bill and body features, though males had a slightly thicker bill and longer wings and tail than females. Diet was dominated in both sexes by a very wide range of arthropod species and a few fleshy fruits, but the overall diet diversity was higher for males than females, and there was a much higher frequency of occurrence of ants in female (58%) than male (29%) diets. We hypothesize that the observed sexual differentiation was likely related to females foraging closer to their offspring on abundant prey, while males consumed a wider variety of prey while foraging more widely. Overall, our results suggest that dietary sexual differentiation in birds may be more widespread than recognized at present and that multi‐marker DNA metabarcoding is a particularly powerful tool to unveiling such differences.
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Affiliation(s)
- Luís P da Silva
- CIBIO-InBIO Research Center in Biodiversity and Genetic Resources University of Porto Vairão Portugal
| | - Vanessa A Mata
- CIBIO-InBIO Research Center in Biodiversity and Genetic Resources University of Porto Vairão Portugal
| | | | - Ricardo J Lopes
- CIBIO-InBIO Research Center in Biodiversity and Genetic Resources University of Porto Vairão Portugal
| | - Pedro Beja
- CIBIO-InBIO Research Center in Biodiversity and Genetic Resources University of Porto Vairão Portugal.,CIBIO-InBIO Research Center in Biodiversity and Genetic Resources Institute of Agronomy University of Lisbon Lisbon Portugal
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