Abstract
Pollination is a key ecological process sustaining biodiversity and food security, yet global patterns of plant–pollinator specialization remain unresolved. Using a global dataset of quantitative plant–pollinator networks (>3,400 networks, >110,000 interactions), we show that specialization is latitudinally structured, but not as a single directional pattern. We find no consistent monotonic increase or decrease in specialization towards the Equator. Instead, network-level and pollinator specialization peak at low northern latitudes near the tropical–subtropical boundary, whereas plant specialization is hemispherically asymmetric. Climate is most often the best-supported predictor of specialization compared with latitude, biodiversity and environmental productivity. Network-level specialization declines with increasing mean annual temperature, with strong group-specific differences. Precipitation exerts nonlinear effects: plant specialization peaks at intermediate precipitation but is lower at the wettest sites, whereas pollinator specialization is lower at intermediate precipitation, although often in interaction with temperature. Pollinator groups diverge strongly, especially in contrasting precipitation-related patterns between birds and insects. These findings show that global plant–pollinator specialization is structured by latitude and climate in complex and taxon-specific ways, with implications for uneven responses of pollination networks to future climatic change.
This is a preview of subscription content, access via your institution
Access options
Access Nature and 54 other Nature Portfolio journals
Get Nature+, our best-value online-access subscription
$32.99 / 30 days
cancel any time
Subscribe to this journal
Receive 12 digital issues and online access to articles
$119.00 per year
only $9.92 per issue
Buy this article
- Purchase on SpringerLink
- Instant access to the full article PDF.
USD 39.95
Prices may be subject to local taxes which are calculated during checkout
Data availability
All data used for modelling (all network characteristics, including specialization metrics, together with all explanatory variables and other metadata) are available via Zenodo at https://doi.org/10.5281/zenodo.19118146 (ref. 71). Note that raw interaction matrices are not publicly available because they are often part of ongoing projects. Requests for access to these data should be directed to S.P.S. or R. Tropek, who will coordinate the request with the contributing authors, aiming to respond within a month. The contributing authors will collectively make access decisions.
Code availability
Complete R code used for this analysis is available via Zenodo at https://doi.org/10.5281/zenodo.19118146 (ref. 71).
References
Armbruster, W. S. & Muchhala, N. Associations between floral specialization and species diversity: cause, effect, or correlation? Evol. Ecol. 23, 159–179 (2009).
Google Scholar
Van Der Niet, T. & Johnson, S. D. Phylogenetic evidence for pollinator-driven diversification of angiosperms. Trends Ecol. Evol. 27, 353–361 (2012).
Google Scholar
Ollerton, J. Pollinator diversity: distribution, ecological function, and conservation. Annu. Rev. Ecol. Evol. Syst. 48, 353–376 (2017).
Google Scholar
Kay, K. M. & Sargent, R. D. The role of animal pollination in plant speciation: integrating ecology, geography, and genetics. Annu. Rev. Ecol. Evol. Syst. 40, 637–656 (2009).
Google Scholar
Pinheiro, R. B. P., Felix, G. M. F., Bell, J. A. & Fecchio, A. The latitudinal specialization gradient of bird–malarial parasite networks in South America: lower connectance, but more evenly distributed interactions towards the equator. Ecography 2024, e06763 10.1111/ecog.06763 (2024).
Google Scholar
Hargreaves, A. L. Geographic gradients in species interactions: from latitudinal patterns to ecological mechanisms. Annu. Rev. Ecol. Evol. Syst. 55, 369–393 (2024).
Google Scholar
Schleuning, M. et al. Specialization of mutualistic interaction networks decreases toward tropical latitudes. Curr. Biol. 22, 1925–1931 (2012).
Google Scholar
Moles, A. T. & Ollerton, J. Is the notion that species interactions are stronger and more specialized in the tropics a zombie idea? Biotropica 48, 141–145 (2016).
Google Scholar
Dobzhansky, T. Evolution in the tropics. Am. Sci. 38, 208–221 (1950).
MacArthur, R. H. Geographical Ecology: Patterns in the Distribution of Species (Harper & Row, 1972).
Schemske, D. W., Mittelbach, G. G., Cornell, H. V., Sobel, J. M. & Roy, K. Is there a latitudinal gradient in the importance of biotic interactions? Annu. Rev. Ecol. Evol. Syst. 40, 245–269 (2009).
Google Scholar
Pauw, A. Can pollination niches facilitate plant coexistence? Trends Ecol. Evol. 28, 30–37 (2013).
Google Scholar
Brown, J. H. Why are there so many species in the tropics? J. Biogeogr. 41, 8–22 (2014).
Google Scholar
Vázquez, D. P. & Stevens, R. D. The latitudinal gradient in niche breadth: concepts and evidence. Am. Nat. 164, E1–E19 (2004).
Google Scholar
Luna, P., Villalobos, F., Escobar, F., Neves, F. S. & Dáttilo, W. Global trends in the trophic specialisation of flower-visitor networks are explained by current and historical climate. Ecol. Lett. 25, 113–124 (2022).
Google Scholar
Ollerton, J. & Cranmer, L. Latitudinal trends in plant-pollinator interactions: are tropical plants more specialised? Oikos 98, 340–350 (2002).
Google Scholar
Rahimi, E. & Jung, C. Assessing the relationship between latitude and plant-pollinator network specialization. J. Ecol. Environ. 48, 256–262 (2024).
Google Scholar
Dalsgaard, B. et al. Specialization in plant-hummingbird networks is associated with species richness, contemporary precipitation and quaternary climate-change velocity. PLOS One 6, e25891 (2011).
Google Scholar
Trøjelsgaard, K. & Olesen, J. M. Macroecology of pollination networks. Glob. Ecol. Biogeogr. 22, 149–162 (2013).
Google Scholar
Vizentin-Bugoni, J. et al. Plant-pollinator networks in the tropics: a review. In Ecological Networks in the Tropics (eds Dáttilo, W. & Rico-Gray, V.) 73–91 (Springer, 2018).
Pauw, A. & Stanway, R. Unrivalled specialization in a pollination network from South Africa reveals that specialization increases with latitude only in the Southern Hemisphere. J. Biogeogr. 42, 652–661 (2015).
Google Scholar
Cirtwill, A. R. et al. The latitudinal biotic interaction hypothesis revisited: contrasting latitudinal richness gradients in actively vs. passively accumulated interaction partners of honey bees. BMC Ecol. Evol. 25, 24 (2025).
Google Scholar
Gorostiague, P., Ollerton, J. & Ortega-Baes, P. Latitudinal gradients in biotic interactions: are cacti pollination systems more specialized in the tropics? Plant Biol. 25, 187–191 (2023).
Google Scholar
Olesen, J. M. & Jordano, P. Geographic patterns in plant-pollinator mutualistic networks. Ecology 83, 2416–2424 (2002).
Ollerton, J., Killick, A., Lamborn, E., Watts, S. & Whiston, M. Multiple meanings and modes: on the many ways to be a generalist flower. Taxon 56, 717–728 (2007).
Google Scholar
Armbruster, W. S. The specialization continuum in pollination systems: diversity of concepts and implications for ecology, evolution and conservation. Funct. Ecol. 31, 88–100 (2017).
Google Scholar
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. Glob. Change Biol. 27, 1266–1280 (2021).
Google Scholar
Brimacombe, C., Bodner, K. & Fortin, M.-J. How network size strongly determines trophic specialisation: a technical comment on Luna et al. (2022). Ecol. Lett. 25, 1914–1916 (2022).
Google Scholar
Classen, A. et al. Specialization of plant–pollinator interactions increases with temperature at Mt. Kilimanjaro. Ecol. Evol. 10, 2182–2195 (2020).
Google Scholar
Bailey, S. et al. Primary productivity and species richness: relationships among functional guilds, residency groups and vagility classes at multiple spatial scales. Ecography 27, 207–217 (2004).
Google Scholar
Vázquez, D. P., Blüthgen, N., Cagnolo, L. & Chacoff, N. P. Uniting pattern and process in plant-animal mutualistic networks: a review. Ann. Bot. 103, 1445–1457 (2009).
Google Scholar
Orr, M. C. et al. Global patterns and drivers of bee distribution. Curr. Biol. 31, 451–458 (2021).
Google Scholar
Elberling, H. & Olesen, J. M. The structure of a high latitude plant-flower visitor system: the dominance of flies. Ecography 22, 314–323 (1999).
Google Scholar
Brown, J. H., Gillooly, J. F., Allen, A. P., Savage, V. M. & West, G. B. Toward a metabolic theory of ecology. Ecology 85, 1771–1789 (2004).
Google Scholar
Petanidou, T. et al. Climate drives plant–pollinator interactions even along small-scale climate gradients: the case of the Aegean. Plant Biol. 20, 176–183 (2018).
Google Scholar
Fenner, M. The phenology of growth and reproduction in plants. Perspect. Plant Ecol. Evol. Syst. 1/1, 78–91 (1998).
Google Scholar
Rafferty, N. E., CaraDonna, P. J. & Bronstein, J. L. Phenological shifts and the fate of mutualisms. Oikos 124, 14–21 (2015).
Google Scholar
Song, B. et al. Global analysis of floral longevity reveals latitudinal gradients and biotic and abiotic correlates. N. Phytol. 235, 2054–2065 (2022).
Google Scholar
Dzekashu, F. F. et al. Seasonal and elevational changes of plant-pollinator interaction networks in East African mountains. Ecol. Evol. 13, e10060 (2023).
Google Scholar
Glaum, P., Wood, T. J., Morris, J. R. & Valdovinos, F. S. Phenology and flowering overlap drive specialisation in plant–pollinator networks. Ecol. Lett. 24, 2648–2659 (2021).
Google Scholar
Maicher, V. et al. Flying between raindrops: strong seasonal turnover of several Lepidoptera groups in lowland rainforests of Mount Cameroon. Ecol. Evol. 8, 12761–12772 (2018).
Google Scholar
Aizen, M. A. Down-facing flowers, hummingbirds and rain. Taxon 52, 675–680 (2003).
Klomberg, Y. et al. Spatiotemporal variation in the role of floral traits in shaping tropical plant-pollinator interactions. Ecol. Lett. 25, 839–850 (2022).
Google Scholar
Lefebvre, V., Villemant, C., Fontaine, C. & Daugeron, C. Altitudinal, temporal and trophic partitioning of flower-visitors in Alpine communities. Sci. Rep. 8, 4706 (2018).
Google Scholar
Saunders, M. E. et al. Climate mediates roles of pollinator species in plant–pollinator networks. Glob. Ecol. Biogeogr. 32, 511–518 (2023).
Google Scholar
Chmel, K. et al. Bird pollination syndrome is the plant’s adaptation to ornithophily, but nectarivorous birds are not so selective. Oikos 130, 1411–1424 (2021).
Google Scholar
Willmer, P. Pollination and Floral Ecology (Princeton Univ. Press, 2011).
Bartomeus, I. et al. Climate-associated phenological advances in bee pollinators and bee-pollinated plants. Proc. Natl Acad. Sci. USA 108, 20645–20649 (2011).
Google Scholar
Biella, P., Akter, A., Ollerton, J., Nielsen, A. & Klecka, J. An empirical attack tolerance test alters the structure and species richness of plant–pollinator networks. Funct. Ecol. 34, 2246–2258 (2020).
Google Scholar
Kudo, G. & Ida, T. Y. Early onset of spring increases the phenological mismatch between plants and pollinators. Ecology 94, 2311–2320 (2013).
Google Scholar
R Core Team. R: A Language and Environment for Statistical Computing (R Foundation for Statistical Computing, 2025).
Poisot, T. et al. mangal – making ecological network analysis simple. Ecography 39, 384–390 (2016).
Google Scholar
Fortuna, M. A., Ortega, R. & Bascompte, J. The web of life. Preprint at https://doi.org/10.48550/arXiv.1403.2575 (2014).
Butterill, P., Jorge, L., Xing, S. & Fayle, T. LifeWebs: a (global) database of bipartite ecological interaction networks. Biodivers. Inf. Sci. Stand. 5, e75626 (2021).
Hijmans, R. J. et al. terra: spatial data analysis. R package version 1.9-25 (2025).
Fick, S. E. & Hijmans, R. J. WorldClim 2: new 1-km spatial resolution climate surfaces for global land areas. Int. J. Climatol. 37, 4302–4315 (2017).
Google Scholar
Didan, K. MODIS/terra vegetation indices 16-day L3 global 250m SIN Grid V006. NASA https://doi.org/10.5067/MODIS/MOD13Q1.006 (2015).
Cai, L. et al. Global models and predictions of plant diversity based on advanced machine learning techniques. N. Phytol. 237, 1432–1445 (2023).
Google Scholar
Jenkins, C. N., Pimm, S. L. & Joppa, L. N. Global patterns of terrestrial vertebrate diversity and conservation. Proc. Natl Acad. Sci. USA 110, E2602–E2610 (2013).
Google Scholar
Daru, B. H. A global database of butterfly species native distributions. Ecology 106, e4462 https://doi.org/10.1002/ecy.4462 (2025).
Google Scholar
Hijmans, R. J. et al. raster: geographic data analysis and modeling. R package version 3.6-32 (2025).
Chamberlain, S. A. & Szöcs, E. taxize: taxonomic search and retrieval in R. F1000Res. 2, 191 (2013).
Google Scholar
GBIF Secretariat. GBIF backbone taxonomy. GBIF https://doi.org/10.15468/39OMEI (2023).
Ollerton, J. Pollinators & Pollination: Nature and Society (Pelagic, 2021).
Dormann, C. F., Gruber, B. & Fründ, J. Introducing the bipartite package: analysing ecological networks. R J. 8, 8–11 (2008).
Blüthgen, N., Menzel, F. & Blüthgen, N. Measuring specialization in species interaction networks. BMC Ecol. 6, 9 (2006).
Google Scholar
Blüthgen, N. & Staab, M. A critical evaluation of network approaches for studying species interactions. Annu. Rev. Ecol. Evol. Syst. 55, 65–88 (2024).
Google Scholar
Chiu, C.-H., Chao, A., Vogel, S., Kriegel, P. & Thorn, S. Quantifying and estimating ecological network diversity based on incomplete sampling data. Philos. Trans. R. Soc. B 378, 20220183 (2023).
Google Scholar
Pedersen, E. J., Miller, D. L., Simpson, G. L. & Ross, N. Hierarchical generalized additive models in ecology: an introduction with mgcv. PeerJ 7, e6876 (2019).
Google Scholar
Wood, S. N. Fast stable restricted maximum likelihood and marginal likelihood estimation of semiparametric generalized linear models. J. R. Stat. Soc. B 73, 3–36 (2011).
Google Scholar
Sakhalkar, S. P. et al. Modelling data and codebase for Sakhalkar, S.P. et al., (2026). Global patterns in plant–pollinator specialisation. Nature Ecology & Evolution (accepted). Zenodo https://doi.org/10.5281/zenodo.19118146 (2026).
Pianka, E. R. Latitudinal gradients in species diversity: a review of concepts. Am. Nat. 100, 33–46 (1966).
Google Scholar
Acknowledgements
We are grateful to everybody who assisted with sampling of the analysed datasets, especially to E. L. S. Bezerra, K. Chmel, J. Queiroz and P. Willmer; to O. Mottl for priceless statistical advice; and to S. D. Leonhardt, M. Volf, T. Kočárková, F. Papandreou, J. Oñate-Casado, R. Pernice and C. Charalambous for feedback on earlier versions of this manuscript. We used GPT large language models (ChatGPT, OpenAI, models 4.5, 4o, 4-turbo, 5 and 5.2 from June 2024 to March 2026) to assist in improving the clarity, readability and stylistic refinement of the manuscript text.
Funding
This study was funded by the Czech Science Foundation grant no. 21-24186 M (to S.P.S., D.A., J.F., Š.J., I.N.K., A.S. and R. Tropek). Individual datasets and co-authors were supported by Alexander von Humboldt Foundation (grant no. 1134644), São Paulo Research Foundation (grant nos. 2023/03083-6, 2023/02881-6, 2023/17728-9) and Consulate General of France in São Paulo (all previous to M.A.R.M.); Bavarian State Ministry of Science and Art (to F.M.); Biotechnology and Biological Sciences Research Council (to L.V.D.); Center for Research on Biodiversity Dynamics and Climate Change, CEPID–FAPESP (grant no. 2021/10639-5 to F.W.A. and C.S.B.); National Council for Scientific and Technological Development, CNPq (grant no. 308559/2022-3 to F.W.A., C.S.B.; grant no. 141736/2020-8 to A.C.P.M.; grant nos. 311665/2022-5, 400904/2019-5 and 423939/2021-1 to J.P.R.B.; grant no. 310508/2019-3 to I.C.M.; grant no. 309893/2023-2 to L.M.S.A.; grant no. 177005/2024-6 to V.H.D.S.; grant no. 305204/2024-6 to M.A.R.M; grant no. 311665/2022-5 to A.R.R.); CAPES (Finance Code 001; COOPBRASS: grant no. 88887.947041/2024-00 to A.C.P.M.; grant no. 177005/2024-6 to V.H.D.S.; PROEX grant no. 88882.347259/2019-01 to U.M.D.); Brazilian Biodiversity Fund, FunBio (grant no. 004/2021 to I.N.G.; grant no. 029/2022 to V.H.D.S.); Rufford Foundation (grant no. 377031 to I.N.G.; grant no. 28478-1 to U.M.D.); Czech Science Foundation (grant no. 19-14620S; T.M.F.); German Research Foundation DFG (grant no. 152112243 to F.L.-E.); Dirección General de Investigación, Universidad de San Carlos de Guatemala (grant no. 4.8.63.2.27–2012 to E.C. and N.E.K.; grant nos. 4.8.63.8.60–2018 and 4.8.63.4.41–2020 to P. Landaverde); FAPEMIG (grant no. RED-00039-23 to P.K.M. and A.R.R.); INCT Pollination (CNPq/CAPES/FAPERJ Call grant no. 58/2022 to P.K.M. and A.R.R.); Faculty for Future, Schlumberger Foundation (Q.B.C.-A., P. Landaverde); the Human Frontier Science Program (grant no. RGP023/2023 to C.J.v.d.K.); European Research Council ERC (grant no. 101054177 to A.T.; grant no. 819374 to Y.C., V.H. and T. Krausl); Knut and Alice Wallenberg Foundation (KAW grant no. 2019.0202 to A.D.B. and W.H.A.O.); LIFE project Olivares Vivos+ (LIFE20 grant no. NAT/ES/001487 to P.J.R.); Missouri Department of Conservation (grant no. K02442-PI0242-022 to R.N.A., M. Mayberry and A.L.R.); National Science Foundation (grant no. DGE-2244337 to L.A.D.); OAPN grant no. 014/2009 (to M. Méndez); CONAHCYT (grant no. CBF2023-2024-216 to W.D.); Spanish Ministry of Science, Innovation and Universities (grant nos. PID2021-127900NB-I00, PGC2018-098498-A-100 and RYC2021-032351-I to A.M.); Israel Ministry of Environmental Protection (grant no. 121-5-13 to T. Keasar); and funding of iDiv via the German Research Foundation DFG (FZT 118, grant no. 202548816 to T.M.K.). Computational resources were provided by the e-INFRA CZ project (ID:90254), supported by the Ministry of Education, Youth and Sports of the Czech Republic.
Author information
Authors and Affiliations
Contributions
S.P.S. and R. Tropek conceived and designed the study, with substantial input from N.B.; S.P.S. collated and processed the datasets and performed the analyses under the supervision of R. Tropek, with feedback from N.B., B.D., C.F.D., C.N.K.-B., D.P.V., J.O., J.R., L.A.B., M.S., P.C. and T.M.K. S.P.S and R. Tropek prepared all visualizations, tables and supplementary materials, with contributions from D.A., J.F. and G.U.-G. S.P.S. and R. Tropek wrote the manuscript draft, with contributions from N.B., B.D., C.F.D., C.N.K.-B., D.P.V., J.O., J.R., L.A.B., M.S., P.C., T.M.K. and T.M.F. All authors contributed data, critically reviewed the manuscript and approved the final version for submission.
Corresponding authors
Ethics declarations
Competing interests
The authors declare no competing interests.
Peer review
Peer review information
Nature Ecology & Evolution thanks Mário Almeida-Neto and the other, anonymous, reviewer(s) for their contribution to the peer review of this work. Peer reviewer reports are available.
Additional information
Publisher’s note Springer Nature remains neutral with regard to jurisdictional claims in published maps and institutional affiliations.
Extended data
Extended Data Fig. 1 Sampling completeness of the analysed networks.
(a–j) Kernel density distributions of sampling completeness (%) for the all networks dataset (a), the full networks dataset (f), and individual functional groups in the functional-group networks dataset (b–e, g–j); panel labels report sample sizes (n). (k) Latitudinal distribution of low-completeness networks, shown as the proportion of networks with sampling completeness ≤ 0.7 in 10° latitudinal bins for each dataset and functional group in the functional-group networks dataset. Credit: Silhouettes from PhyloPic (https://www.phylopic.org/) under a Creative Commons license: Halictus rubicundus (CC BY 4.0); Acanthorhynchus tenuirostris (CC0 1.0).
Extended Data Fig. 2 Latitudinal patterns in plant–pollinator specialisation metrics for the all networks dataset.
Panels show specialisation metrics: network-level H2’ (a); and community-mean species-level separated for pollinators (d’pollinators; b) and for plants (d’plants; c). Vertical dashed line marks the equator (0°), and vertical dotted lines mark the Tropics of Capricorn (-23.5°) and Cancer (23.5°). Curves are GAMM/HGAM fitted mean response smooths: black curves indicate overall latitudinal trends with 95% confidence intervals (grey shading), coloured curves represent significant functional group-specific trends (see legend). Coloured points are raw data. Curves are drawn only when the smooth term for latitude is significant, otherwise only points are shown. Adjusted R2 and exact p-values for the overall trend are reported in each panel (see Table S5 for full model summaries). We assessed the significance of smooth terms using two-sided approximate F-tests without correction for multiple comparisons. Credit: Silhouettes from PhyloPic (https://www.phylopic.org/) under a Creative Commons license: Onthophagus taurus, Darapsa myron (CC BY 3.0); Acanthorhynchus tenuirostris, Papilio machaon, Tachinidae, Eupeodes volucris, Vespula germanica (CC0 1.0).
Extended Data Fig. 3 Latitudinal distribution of plant–pollinator network descriptors.
Scatterplots show the values of climatic, environmental, and biotic descriptors for individual networks in the all networks dataset plotted against latitude; points are coloured by elevation. Descriptor definitions, abbreviations and units are given in Table S2. Credit: Silhouette from PhyloPic (https://www.phylopic.org/) under a Creative Commons license: Acanthorhynchus tenuirostris (CC0 1.0).
Extended Data Fig. 4 Mean annual temperature as a function of latitude and elevation for the analysed plant-pollinator interaction networks.
Sampling sites are coloured by their elevation. The reported adjusted R2 and significance (***p < 0.001) originate from a linear model predicting mean annual temperature from absolute latitude and elevation (F3,3492 = 8879).
Supplementary information
Supplementary Information (download PDF )
Supplementary Figs. 1–4, Tables 1–9 and References.
Reporting Summary (download PDF )
Peer Review File (download PDF )
Rights and permissions
Springer Nature or its licensor (e.g. a society or other partner) holds exclusive rights to this article under a publishing agreement with the author(s) or other rightsholder(s); author self-archiving of the accepted manuscript version of this article is solely governed by the terms of such publishing agreement and applicable law.
Reprints and permissions
About this article
Cite this article
Sakhalkar, S.P., Blüthgen, N., Burkle, L.A. et al. Global patterns in plant–pollinator specialization.
Nat Ecol Evol (2026). https://doi.org/10.1038/s41559-026-03170-7
Received:
Accepted:
Published:
Version of record:
DOI: https://doi.org/10.1038/s41559-026-03170-7
Source: Ecology - nature.com
