G. Arceo-gómez, A. Schroeder, C. Albor, T. Ashman, T. M. Knight et al., Global geographic patterns of heterospecific pollen receipt help uncover potential ecological and evolutionary impacts across plant communities worldwide, Sci Rep, vol.9, 2019.

W. S. Armbruster, The specialization continuum in pollination systems: diversity of concepts and implications for ecology, evolution and conservation, Functional Ecology, vol.31, pp.88-100, 2017.

G. Ballantyne, K. C. Baldock, L. Rendell, and P. G. Willmer, Pollinator importance networks illustrate the crucial value of bees in a highly speciose plant community, Scientific Reports, vol.7, 2017.

D. J. Barr, R. Levy, C. Scheepers, and H. J. Tily, Random effects structure for confirmatory hypothesis testing: Keep it maximal, Journal of Memory and Language, vol.68, pp.255-278, 2013.

,

O. Bartholomée and S. Lavorel, Disentangling the diversity of definitions for the pollination ecosystem service and associated estimation methods, Ecological Indicators, vol.107, 2019.

I. Bartomeus, D. P. Cariveau, T. Harrison, and R. Winfree, On the inconsistency of pollinator species traits for predicting either response to land-use change or functional contribution, Oikos, vol.127, pp.306-315, 2018.

K. Barto?, MuMIn: Multi-Model Inference, 2019.

D. Bates, M. Mächler, B. Bolker, and S. Walker, Fitting Linear Mixed-Effects Models using lme4, 2014.

M. Baude, W. E. Kunin, N. D. Boatman, S. Conyers, N. Davies et al., Historical nectar assessment reveals the fall and rise of floral resources in Britain, Nature, vol.530, pp.85-88, 2016.

J. Binkenstein, J. P. Renoult, and H. M. Schaefer, Increasing land-use intensity decreases floral 149 colour diversity of plant communities in temperate grasslands, Oecologia, vol.173, pp.461-471, 2013.

N. Blüthgen, C. F. Dormann, D. Prati, V. H. Klaus, T. Kleinebecker et al., A quantitative index of land-use intensity in grasslands: Integrating mowing, grazing and fertilization, Basic and Applied Ecology, vol.13, pp.207-220, 2012.

,

N. Blüthgen and A. Klein, Functional complementarity and specialisation: The role of biodiversity in plant-pollinator interactions, Basic and Applied Ecology, vol.12, pp.282-291, 2011.

,

Z. Botta-dukát, Rao's quadratic entropy as a measure of functional diversity based on multiple traits, Journal of Vegetation Science, vol.16, pp.533-540, 2005.

B. J. Brosi and H. M. Briggs, Single pollinator species losses reduce floral fidelity and plant reproductive function, Proceedings of the National Academy of Sciences, vol.110, pp.13044-13048, 2013.

,

J. H. Brown, J. F. Gillooly, A. P. Allen, V. M. Savage, and G. B. West, Toward a metabolic theory of ecology, Ecology, vol.85, pp.1771-1789, 2004.

L. A. Burkle and R. Alarcon, The future of plant-pollinator diversity: Understanding interaction networks across time, space, and global change, American Journal of Botany, vol.98, pp.528-538, 2011.

L. A. Burkle, C. M. Delphia, and K. M. O'neill, A dual role for farmlands: food security and pollinator conservation, Journal of Ecology, vol.105, pp.890-899, 2017.

K. P. Burnham, D. R. Anderson, and K. P. Burnham, Model selection and multimodel inference: a practical information-theoretic approach, p.150, 2002.

V. Busch, V. H. Klaus, C. Penone, D. Schäfer, S. Boch et al., Nutrient stoichiometry and land use rather than species richness determine plant functional diversity, Ecology and Evolution, vol.8, 2017.

M. W. Cadotte and C. M. Tucker, Should Environmental Filtering be Abandoned?, Trends in Ecology & Evolution, vol.32, pp.429-437, 2017.

J. H. Cane and B. Love, Pollen carryover between sequential foraging trips by a solitary bee: implications for distant outcrossing, JPE, vol.24, p.15, 2018.

J. H. Cane and V. J. Tepedino, Gauging the Effect of Honey Bee Pollen Collection on Native Bee Communities: Apis pollen depletion and native bees, Conservation Letters, vol.10, pp.205-210, 2017.

D. P. Cariveau, G. K. Nayak, I. Bartomeus, J. Zientek, J. S. Ascher et al., The Allometry of Bee Proboscis Length and Its Uses in Ecology, PLOS ONE, vol.11, 2016.

T. Ceulemans, R. Merckx, M. Hens, and O. Honnay, Plant species loss from European seminatural grasslands following nutrient enrichment -is it nitrogen or is it phosphorus?: Does N or P drive species loss?, Global Ecology and Biogeography, vol.22, pp.73-82, 2013.

,

T. Ceulemans, R. Merckx, M. Hens, and O. Honnay, A trait-based analysis of the role of phosphorus vs. nitrogen enrichment in plant species loss across North-west European grasslands: Trait-based analysis of the role of P vs. N enrichment, Journal of Applied Ecology, vol.48, pp.1155-1163, 2011.

T. Ceulemans, C. J. Stevens, L. Duchateau, H. Jacquemyn, D. J. Gowing et al.,

S. Muller, N. B. Dise, C. Dupré, M. Diekmann, and O. Honnay, Soil phosphorus constrains biodiversity across European grasslands, Global Change Biology, vol.20, pp.3814-3822, 2014.
URL : https://hal.archives-ouvertes.fr/hal-01777416

L. Chalmandrier, C. Albouy, and L. Pellissier, Species pool distributions along functional trade-offs shape plant productivity-diversity relationships, Scientific Reports, vol.7, 2017.

,

L. Chittka and N. E. Raine, Recognition of flowers by pollinators, Current Opinion in Plant Biology, vol.9, pp.428-435, 2006.

F. Chollet, Deep learning with Python, 2018.

S. Corbet, J. Bee, K. Dasmahapatra, S. Gale, E. Gorringe et al., Native or Exotic? Double or Single? Evaluating Plants for Pollinator-friendly Gardens, Annals of Botany, vol.87, pp.219-232, 2001.

,

S. A. Corbet, Nectar sugar content: estimating standing crop and secretion rate in the field, Apidologie, vol.34, pp.1-10, 2003.
URL : https://hal.archives-ouvertes.fr/hal-00891647

A. Cornu, A. Farruggia, E. Leppik, C. Pinier, F. Fournier et al., Trapping the Pasture Odorscape Using Open-Air Solid-Phase Micro Extraction, a Tool to Assess Grassland Value, PloS one, vol.10, 2015.

R. W. Cruden, Pollen grains: Why so many?, Plant Systematics and Evolution, vol.222, pp.143-165, 2000.

,

A. De-palma, M. Kuhlmann, S. P. Roberts, S. G. Potts, L. Börger et al., Ecological traits affect the sensitivity of bees to land-use pressures in European agricultural landscapes, Journal of Applied Ecology, vol.52, pp.1567-1577, 2015.

J. Dengler, M. Jani?ová, P. Török, and C. Wellstein, Biodiversity of Palaearctic grasslands: a synthesis, Ecosystems & Environment, vol.182, pp.1-14, 2014.

,

C. Devaux, C. Lepers, and E. Porcher, Constraints imposed by pollinator behaviour on the ecology and evolution of plant mating systems, Journal of Evolutionary Biology, vol.27, pp.1413-1430, 2014.
URL : https://hal.archives-ouvertes.fr/hal-01110833

,

S. Díaz, J. Fargione, F. S. Iii, and D. Tilman, Biodiversity Loss Threatens Human Well-Being, 2006.

, PLoS Biology, vol.4, p.152

S. Díaz, S. Lavorel, and F. De-bello, Incorporating plant functional diversity effects in ecosystem service assessments, Proceedings of the National Academy of Sciences, vol.104, 2007.

L. V. Dicks, M. Baude, S. Roberts, J. Phillips, M. Green et al., How much flower-rich habitat is enough for wild pollinators? Answering a key policy question with incomplete knowledge, Ecological Entomology, vol.40, 2015.

C. F. Dormann, J. Elith, S. Bacher, C. Buchmann, G. Carl et al.,

B. Lafourcade, P. J. Leitão, T. Münkemüller, C. Mcclean, P. E. Osborne et al., Collinearity: a review of methods to deal with it and a simulation study evaluating their performance, Ecography, vol.36, pp.27-46, 2013.

,

C. F. Dormann, J. Fründ, and H. M. Schaefer, Identifying Causes of Patterns in Ecological Networks: Opportunities and Limitations, Annu. Rev. Ecol. Evol. Syst, vol.48, pp.559-584, 2017.

,

C. F. Dormann, B. Gruber, and J. Fründ, Introducing the bipartite Package: Analysing Ecological Networks, 2008.

C. F. Dormann and R. Strauss, A method for detecting modules in quantitative bipartite networks, Methods in Ecology and Evolution, vol.5, pp.90-98, 2014.

S. Dray, P. Choler, S. Dolédec, P. R. Peres-neto, W. Thuiller et al., Combining the fourth-corner and the RLQ methods for assessing trait responses to environmental variation, Ecology, vol.95, pp.14-21, 2014.
URL : https://hal.archives-ouvertes.fr/halsde-00942845

A. Ebeling, A. Klein, J. Schumacher, W. W. Weisser, and T. Tscharntke, How does plant richness affect pollinator richness and temporal stability of flower visits?, Oikos, vol.117, pp.1808-1815, 2008.

,

. Eurostat, Permanent grassland: number of farms and areas by agricultural size of farm (UAA) and size of permanent grassland area, 2007.

M. Filipiak, A Better Understanding of Bee Nutritional Ecology Is Needed to Optimize Conservation Strategies for Wild Bees-The Application of Ecological Stoichiometry, vol.9, 2018.
URL : https://hal.archives-ouvertes.fr/hal-01843201

M. Filipiak, K. Kuszewska, M. Asselman, B. Denisow, E. Stawiarz et al., Ecological stoichiometry of the honeybee: Pollen diversity and adequate species composition are needed to mitigate limitations imposed on the growth and development of bees by pollen quality, PLOS ONE, vol.12, 2017.
URL : https://hal.archives-ouvertes.fr/hal-01578298

M. Fischer, O. Bossdorf, S. Gockel, F. Hänsel, A. Hemp et al.,

J. Nieschulze, S. Pfeiffer, D. Prati, S. Renner, I. Schöning et al.,

E. K. Kalko, K. E. Linsenmair, E. Schulze, and W. W. Weisser, Implementing large-scale and long-term functional biodiversity research: The Biodiversity Exploratories, Basic and Applied Ecology, vol.11, pp.473-485, 2010.

C. Fontaine, I. Dajoz, J. Meriguet, and M. Loreau, Functional Diversity of Plant-Pollinator Interaction Webs Enhances the Persistence of Plant Communities, PLoS Biology, vol.4, 2005.
URL : https://hal.archives-ouvertes.fr/hal-00133390

F. Fornoff, A. Klein, F. Hartig, G. Benadi, C. Venjakob et al., Functional flower traits and their diversity drive pollinator visitation, 2017.

R. E. Fowler, E. L. Rotheray, and D. Goulson, Floral abundance and resource quality influence pollinator choice, Insect Conservation and Diversity, vol.9, pp.481-494, 2016.

,

J. Fründ, C. F. Dormann, A. Holzschuh, and T. Tscharntke, Bee diversity effects on pollination depend on functional complementarity and niche shifts, Ecology, vol.94, pp.2042-2054, 2013.

J. Fründ, K. E. Linsenmair, and N. Blüthgen, Pollinator diversity and specialization in relation to flower diversity, Oikos, vol.119, pp.1581-1590, 2010.

J. Fründ, K. S. Mccann, and N. M. Williams, Sampling bias is a challenge for quantifying specialization and network structure: lessons from a quantitative niche model, Oikos, vol.125, 2015.

R. J. Fuller, L. R. Norton, R. E. Feber, P. J. Johnson, D. E. Chamberlain et al., Benefits of organic farming to biodiversity vary among taxa, Biol. Lett, vol.1, pp.431-434, 2005.

,

S. Gámez-virués, D. J. Perovi?, M. M. Gossner, C. Börschig, N. Blüthgen et al., Landscape simplification filters species traits and drives biotic homogenization, Nature Communications, vol.6, 2015.

L. A. Garibaldi, I. Bartomeus, R. Bommarco, A. M. Klein, S. A. Cunningham et al.,

B. M. Freitas, V. Gagic, A. Holzschuh, B. K. Klatt, K. M. Krewenka et al.,

I. Motzke, M. Otieno, J. Petersen, S. G. Potts, T. H. Ricketts et al., EDITOR'S CHOICE: REVIEW: Trait matching of flower visitors and crops predicts fruit set better than trait diversity, Journal of Applied Ecology, vol.52, pp.1436-1444, 2015.

E. Garnier, S. Lavorel, P. Ansquer, H. Castro, P. Cruz et al.,

H. Freitas, C. Golodets, K. Grigulis, C. Jouany, E. Kazakou et al.,

J. Leps, T. Meier, R. Pakeman, M. Papadimitriou, V. P. Papanastasis et al.,

M. Robson, C. Roumet, G. Rusch, C. Skarpe, M. Sternberg et al., Assessing the Effects of Land-use Change on Plant Traits, Communities and Ecosystem Functioning in Grasslands: A Standardized Methodology and Lessons from an Application to 11 European Sites, Annals of Botany, vol.99, pp.967-985, 2007.
URL : https://hal.archives-ouvertes.fr/halsde-00283760

E. Garnier and M. Navas, A trait-based approach to comparative functional plant ecology: concepts, methods and applications for agroecology. A review. Agronomy for Sustainable Development, vol.32, pp.365-399, 2012.
URL : https://hal.archives-ouvertes.fr/hal-00930507

E. Gaujour, B. Amiaud, C. Mignolet, and S. Plantureux, Factors and processes affecting plant biodiversity in permanent grasslands. A review. Agronomy for Sustainable Development, vol.32, pp.133-160, 2012.
URL : https://hal.archives-ouvertes.fr/hal-00930482

B. Geslin, B. Gauzens, E. Thébault, and I. Dajoz, Plant pollinator networks along a gradient of urbanisation, PloS one, vol.8, p.63421, 2013.
URL : https://hal.archives-ouvertes.fr/hal-01620226

J. M. Gomez, J. Bosch, F. Perfectti, J. D. Fernandez, M. Abdelaziz et al., of the Royal Society B: Biological Sciences, vol.275, pp.2241-2249, 2008.

A. L. González, O. Dézerald, P. A. Marquet, G. Q. Romero, and D. S. Srivastava, The Multidimensional Stoichiometric Niche, Frontiers in Ecology and Evolution, vol.5, 2017.

G. Gorsky, M. D. Ohman, M. Picheral, B. Romagnan, and A. Cawood, Digital zooplankton image analysis using the ZooScan integrated system 32, p.19, 2010.

D. Goulson, The insect apocalypse, and why it matters, Current Biology, vol.29, pp.967-971, 2019.

,

D. Goulson, Bumblebees: behaviour, ecology, and conservation, 2010.

J. B. Grace, T. M. Anderson, E. W. Seabloom, E. T. Borer, P. B. Adler et al.,

B. A. Melbourne, J. W. Morgan, J. L. Orrock, S. M. Prober, and M. D. Smith, Integrative modelling reveals mechanisms linking productivity and plant species richness, Nature, vol.529, pp.390-393, 2016.

S. S. Greenleaf, N. M. Williams, R. Winfree, and C. Kremen, Bee foraging ranges and their relationship to body size, Oecologia, vol.153, pp.589-596, 2007.

J. P. Grime, Plant strategy theories: a comment on Craine, Journal of Ecology, vol.95, pp.227-230, 2005.

J. P. Grime, Benefits of plant diversity to ecosystems: immediate, filter and founder effects, Journal of Ecology, vol.86, 1998.

C. A. Hallmann, M. Sorg, E. Jongejans, H. Siepel, N. Hofland et al.,

A. Müller, H. Sumser, T. Hörren, D. Goulson, and H. De-kroon, More than 75 percent decline over 27 years in total flying insect biomass in protected areas, PLoS ONE, vol.12, 2017.

L. D. Harder and S. C. Barrett, Pollen Dispersal and Mating Patterns in Animal-Pollinated Plants, Floral Biology, pp.140-190, 1996.

A. Hector, Plant Diversity and Productivity Experiments in European Grasslands, Science, vol.286, pp.1123-1127, 1999.

S. J. Hegland and Ø. Totland, Relationships between species' floral traits and pollinator visitation in a temperate grassland, Oecologia, vol.145, pp.586-594, 2005.

K. Helsen, T. Ceulemans, C. J. Stevens, and O. Honnay, Increasing Soil Nutrient Loads of, 2014.

, European Semi-natural Grasslands Strongly Alter Plant Functional Diversity Independently of Species Loss, Ecosystems, vol.17, pp.169-181

N. Hempel-de-ibarra, K. V. Langridge, and M. Vorobyev, More than colour attraction: behavioural functions of flower patterns, Current Opinion in Insect Science, vol.12, pp.64-70, 2015.

,

M. Henry and G. Rodet, Controlling the impact of the managed honeybee on wild bees in protected areas, Scientific Reports, vol.8, 2018.

D. M. Hicks, P. Ouvrard, K. C. Baldock, M. Baude, M. A. Goddard et al.,

J. Memmott, H. Morse, M. Nikolitsi, L. M. Osgathorpe, S. G. Potts et al.,

F. Sinclair, D. B. Westbury, and G. N. Stone, Food for Pollinators: Quantifying the Nectar and Pollen Resources of Urban Flower Meadows, PLOS ONE, vol.11, 2016.

D. U. Hooper, E. C. Adair, B. J. Cardinale, J. E. Byrnes, B. A. Hungate et al., A global synthesis reveals biodiversity loss as a major driver of ecosystem change, Nature, vol.486, pp.105-108, 2012.

A. Hudewenz, A. Klein, C. Scherber, L. Stanke, T. Tscharntke et al., Herbivore and pollinator responses to grassland management 157 intensity along experimental changes in plant species richness, Biological Conservation, vol.150, pp.42-52, 2012.

M. A. Huston, Disturbance, productivity, and species diversity: empiricism vs. logic in ecological theory, Ecology, vol.95, pp.2382-2396, 2014.

C. Huyghe, A. De-vliegher, B. Van-gils, and A. Peeters, Grasslands and herbivore production in Europe and effects of common policies, 2014.
URL : https://hal.archives-ouvertes.fr/hal-01189917

D. W. Inouye, B. M. Larson, A. Ssymank, and P. G. Kevan, Flies and flowers III: ecology of foraging and pollination, J. Pollinat. Ecol, vol.16, pp.115-133, 2015.

, Climate Change and Land An IPCC Special Report on climate change, desertification, land degradation, sustainable land management, food security, and greenhouse gas fluxes in terrestrial ecosystems, IPCC, 2019.

F. Janssens, A. Peeters, J. R. Tallowin, J. P. Bakker, R. M. Bekker et al., Relationship between soil chemical factors and grassland diversity, Plant and soil, vol.202, pp.69-78, 1998.

B. Jauker, J. Krauss, F. Jauker, and I. Steffan-dewenter, Linking life history traits to pollinator loss in fragmented calcareous grasslands, Landscape Ecol, vol.28, 2013.

F. M. Jong, . De, E. Voet, . Van-der, K. J. Canters et al., The side-effects of airborne pesticides on fungi and vascular plants, 1991.

R. R. Junker, N. Blüthgen, T. Brehm, J. Binkenstein, J. Paulus et al., Specialization on traits as basis for the niche-breadth of flower visitors and as structuring mechanism of ecological networks, Functional Ecology, vol.27, pp.329-341, 2013.

,

R. R. Junker, N. Blüthgen, and A. Keller, Functional and phylogenetic diversity of plant communities differently affect the structure of flower-visitor interactions and reveal convergences in floral traits, Evolutionary Ecology, vol.29, pp.437-450, 2015.

,

R. R. Junker and A. L. Parachnowitsch, Working towards a holistic view on flower traits-how floral scents mediate plant-animal interactions in concert with other floral characters, Journal of the Indian Institute of Science, vol.95, pp.43-68, 2015.

A. Jürgens and M. Bischoff, Changing odour landscapes: the effect of anthropogenic volatile pollutants on plant-pollinator olfactory communication, Functional Ecology, vol.31, pp.56-64, 2017.

,

W. Kämper, C. Weiner, S. Kühsel, C. Storm, T. Eltz et al., Evaluating the effects of floral resource specialisation and of nitrogen regulation on the vulnerability of social bees in agricultural landscapes, Apidologie, vol.48, pp.371-383, 2017.

C. A. Kearns and D. W. Inouye, Techniques for pollination biologists, 1993.

L. K. Kendall, R. Rader, V. Gagic, D. P. Cariveau, M. Albrecht et al.,

J. Rodriguez, L. Russo, L. Sutter, N. J. Vereecken, and I. Bartomeus, Pollinator size and its consequences: Robust estimates of body size in pollinating insects, Ecology and Evolution, vol.9, 2019.

P. Kevan, M. Giurfa, and L. Chittka, Why are there so many and so few white flowers?, Trends in Plant Science, vol.1, p.252, 1996.

C. King, G. Ballantyne, and P. G. Willmer, Why flower visitation is a poor proxy for pollination: measuring single-visit pollen deposition, with implications for pollination networks and conservation, Methods in Ecology and Evolution, vol.4, pp.811-818, 2013.

S. G. Klumpers, M. Stang, and P. G. Klinkhamer, Foraging efficiency and size matching in a plant-pollinator community: the importance of sugar content and tongue length, Ecology Letters, vol.22, pp.469-479, 2019.

L. Koch, K. Lunau, and P. Wester, To be on the safe site -Ungroomed spots on the bee's body and their importance for pollination, PLoS ONE, vol.12, p.182522, 2017.

,

N. J. Kraft, P. B. Adler, O. Godoy, E. C. James, S. Fuller et al., Community assembly, coexistence and the environmental filtering metaphor, Functional Ecology, vol.29, pp.592-599, 2015.

H. W. Krenn, J. D. Plant, and N. U. Szucsich, Mouthparts of flower-visiting insects, Arthropod Structure & Development, vol.34, pp.1-40, 2005.

S. Kühsel, Pollinator trait diversity: functional implications at different land-use intensities and environmental conditions (PhD dissertation). Department of Biology, 2015.

S. Kühsel and N. Blüthgen, High diversity stabilizes the thermal resilience of pollinator communities in intensively managed grasslands, Nature Communications, vol.6, 2015.

E. Kuusela and J. Lämsä, A low-cost, computer-controlled robotic flower system for behavioral experiments, Ecol Evol, vol.6, pp.2594-2600, 2016.

A. Kuznetsova, P. B. Brockhoff, and R. H. Christensen, lmerTest Package: Tests in Linear Mixed Effects Models, Journal of Statistical Software, vol.82, 2017.

E. Laliberté, P. Legendre, and B. Shipley, , 2014.

E. Laliberte, G. Zemunik, and B. L. Turner, Environmental filtering explains variation in plant diversity along resource gradients, Science, vol.345, pp.1602-1605, 2014.

,

B. M. Larson and S. C. Barrett, A comparative analysis of pollen limitation in flowering plants, Biological Journal of the Linnean Society, vol.69, pp.503-520, 2000.

A. C. Larue, R. A. Raguso, and R. R. Junker, Experimental manipulation of floral scent bouquets restructures flower-visitor interactions in the field, Journal of Animal Ecology, vol.85, pp.396-408, 2016.

S. Lavorel and É. Garnier, Predicting changes in community composition and ecosystem functioning from plant traits: revisiting the Holy Grail, Functional ecology, vol.16, pp.545-556, 2002.

S. Lavorel, J. Storkey, R. D. Bardgett, F. De-bello, M. P. Berg et al., A novel framework for linking functional diversity of plants with other trophic levels for the quantification of ecosystem services, Journal of Vegetation Science, vol.24, pp.942-948, 2013.
URL : https://hal.archives-ouvertes.fr/hal-02522208

P. Laytner, C. Ling, and Q. Xiao, Robust face detection from still images, 2014 IEEE Symposium on Computational Intelligence in Biometrics and Identity Management (CIBIM), 2014.

, 2014 IEEE Symposium on Computational Intelligence in Biometrics and Identity Management (CIBIM), pp.76-80

,

L. Provost, G. Gross, N. Börger, L. Deraison, H. Roncoroni et al., Traitmatching and mass effect determine the functional response of herbivore communities to landuse intensification, Functional Ecology, vol.31, pp.1600-1611, 2017.
URL : https://hal.archives-ouvertes.fr/hal-01498580

S. Lê, J. Josse, and F. Husson, FactoMineR : An R Package for Multivariate Analysis, Journal of Statistical Software, vol.25, 2008.

V. Lefebvre, C. Fontaine, C. Villemant, and C. Daugeron, Are empidine dance flies major flower visitors in alpine environments? A case study in the Alps, France. Biol. Lett, vol.10, 2014.

A. S. Leonard, A. Dornhaus, and D. R. Papaj, Why are floral signals complex? An outline of functional hypotheses, pp.279-300, 2011.

A. S. Leonard and P. Masek, Multisensory integration of colors and scents: insights from bees and flowers, Journal of Comparative Physiology A, vol.200, pp.463-474, 2014.

,

K. Lunau and E. J. Maier, Innate colour preferences of flower visitors, Journal of Comparative Physiology A, vol.177, 1995.

R. Lundgren, Ø. Totland, and A. Lázaro, Experimental simulation of pollinator decline causes community-wide reductions in seedling diversity and abundance, Ecology, vol.97, pp.1420-1430, 2016.

E. H. Mamdani and S. Assilian, An Experiment in Linguistic Synthesis with a Fuzzy Logic Controller, International journal of man-machine studies, vol.7, pp.1-13, 1975.

N. W. Mason, F. De-bello, D. Mouillot, S. Pavoine, and S. Dray, A guide for using functional diversity indices to reveal changes in assembly processes along ecological gradients, Journal of Vegetation Science, vol.24, pp.794-806, 2013.
URL : https://hal.archives-ouvertes.fr/hal-02281571

N. W. Mason, D. Mouillot, W. G. Lee, and J. B. Wilson, Functional richness, functional evenness and functional divergence: the primary components of functional diversity, Oikos, vol.111, 2005.

B. Mcgill, B. Enquist, E. Weiher, and M. Westoby, Rebuilding community ecology from functional traits, Trends in Ecology & Evolution, vol.21, pp.178-185, 2006.

,

A. Michaud, S. Plantureux, E. Pottier, J. Farriè, F. Launay et al., Une typologie nationale des prairies permanentes : un outil pour caractériser leur potentiel fourrager et leur intérêt environnemental, Renc. Rech. Ruminants, vol.18, 2011.

C. D. Michener, The bees of the world, 2007.

M. Moretti, A. T. Dias, F. De-bello, F. Altermatt, S. L. Chown et al., Handbook of protocols for standardized measurement of terrestrial invertebrate functional traits, Funct Ecol, vol.31, pp.558-567, 2017.
URL : https://hal.archives-ouvertes.fr/hal-01690257

M. A. Mouchet, S. Villéger, N. W. Mason, and D. Mouillot, Functional diversity measures: an overview of their redundancy and their ability to discriminate community assembly rules: Functional diversity measures, Functional Ecology, vol.24, pp.867-876, 2010.

A. Müller, S. Diener, S. Schnyder, K. Stutz, C. Sedivy et al., Quantitative pollen requirements of solitary bees: Implications for bee conservation and the evolution of beeflower relationships, Biological Conservation, vol.130, pp.604-615, 2006.

,

S. Nakagawa and H. Schielzeth, A general and simple method for obtaining R 2 from generalized linear mixed-effects models, Methods in Ecology and Evolution, vol.4, pp.133-142, 2013.

R. N. Nichols, D. Goulson, and J. M. Holland, The best wildflowers for wild bees, J Insect Conserv, 2019.

T. Nicolson, Nectar chemistry, Nectaries and Nectar, pp.215-264, 2007.

A. Nieto, S. P. Roberts, J. Kemp, P. Rasmont, M. Kuhlmann et al., European Commission, Directorate-General for the Environment, IUCN (International Union for Conservation of Nature), 2014.

J. Ollerton, Pollinator Diversity: Distribution, Ecological Function, and Conservation, 2017.

, Annu. Rev. Ecol. Evol. Syst, vol.48, pp.353-376

J. Ollerton, R. Winfree, and S. Tarrant, How many flowering plants are pollinated by animals?, Oikos, vol.120, pp.321-326, 2011.

K. A. Orford, P. J. Murray, I. P. Vaughan, and J. Memmott, Modest enhancements to conventional grassland diversity improve the provision of pollination services, Journal of Applied Ecology, vol.53, pp.906-915, 2016.

S. Osorio-canadas, X. Arnan, A. Rodrigo, A. Torné-noguera, R. Molowny et al., Body size phenology in a regional bee fauna: a temporal extension of Bergmann's rule, Ecology Letters, vol.19, pp.1395-1402, 2016.

R. J. Pakeman, R. L. Hewison, D. Riach, J. M. Fisher, S. Hurskainen et al., Long-term functional structure and functional diversity changes in Scottish grasslands, Ecosystems & Environment, vol.247, pp.352-362, 2017.

,

A. D. Papanikolaou, I. Kühn, M. Frenzel, M. Kuhlmann, P. Poschlod et al., , p.163

O. Schweiger, Wild bee and floral diversity co-vary in response to the direct and indirect impacts of land use. Ecosphere 8, e02008, 2017.

L. Pellissier, N. Alvarez, and A. Guisan, Pollinators as drivers of plant distribution and assemblage into communities. Evolution of Plant-Pollinator Relationships, Systematics Association Special, vol.Series, pp.392-413, 2012.

B. B. Phillips, A. Williams, J. L. Osborne, and R. F. Shaw, Shared traits make flies and bees effective pollinators of oilseed rape (Brassica napus L.), Basic and Applied Ecology, vol.32, pp.66-76, 2018.

,

A. Pornon, C. Andalo, M. Burrus, and N. Escaravage, DNA metabarcoding data unveils invisible pollination networks, Sci Rep, vol.7, 2017.

S. G. Potts, J. C. Biesmeijer, C. Kremen, P. Neumann, O. Schweiger et al., Global pollinator declines: trends, impacts and drivers, Trends in Ecology & Evolution, vol.25, pp.345-353, 2010.

,

S. G. Potts, B. Vulliamy, A. Dafni, G. Ne'eman, and P. Willmer, LINKING BEES AND FLOWERS: HOW DO FLORAL COMMUNITIES STRUCTURE POLLINATOR COMMUNITIES?, vol.84, p.15, 2003.

S. G. Potts, B. Vulliamy, S. Roberts, C. O'toole, A. Dafni et al., Nectar resource diversity organises flower-visitor community structure, Entomologia experimentalis et applicata, vol.113, pp.103-107, 2004.

S. G. Potts, B. A. Woodcock, S. P. Roberts, T. Tscheulin, E. S. Pilgrim et al., Enhancing pollinator biodiversity in intensive grasslands, Journal of Applied Ecology, vol.46, pp.369-379, 2009.

A. Poutaraud, A. Michelot-antalik, and S. Plantureux, Grasslands: A Source of Secondary Metabolites for Livestock Health, Journal of Agricultural and Food Chemistry, vol.65, pp.6535-6553, 2017.

,

C. J. Praz, A. Müller, and S. Dorn, Specialized bees fail to develop on non-host pollen: do plants chemically protect their pollen, Ecology, vol.89, pp.795-804, 2008.

J. Pretty, Agricultural sustainability: concepts, principles and evidence, Phil. Trans. R. Soc. B, vol.363, pp.447-465, 2008.

F. Ratnieks and K. Shackleton, Does the waggle dance help honey bees to forage at greater distances than expected for their body size?, Frontiers in Ecology and Evolution, vol.3, p.7, 2015.

J. P. Renoult, N. Blüthgen, J. Binkenstein, C. N. Weiner, M. Werner et al., The relative importance of color signaling for plant generalization in pollination networks, Oikos, vol.124, pp.347-354, 2015.

J. P. Renoult, A. Kelber, and H. M. Schaefer, Colour spaces in ecology and evolutionary biology: Colour spaces in ecology and evolutionary biology, Biological Reviews, vol.92, pp.292-315, 2017.

,

N. Roger, D. Michez, R. Wattiez, C. Sheridan, and M. Vanderplanck, Diet effects on bumblebee health, Journal of Insect Physiology, vol.96, pp.128-133, 2017.

,

T. H. Roulston and K. Goodell, The Role of Resources and Risks in Regulating Wild Bee Populations, Annual Review of Entomology, vol.56, pp.293-312, 2011.

M. Schleuning, J. Fründ, and D. García, Predicting ecosystem functions from biodiversity and mutualistic networks: an extension of trait-based concepts to plant-animal interactions, Ecography, vol.38, pp.380-392, 2015.

D. Schleuter, M. Daufresne, F. Massol, and C. Argiliier, A user's guide to functional diversity indices, Ecology, vol.80, 2010.

A. Schneider, Les légumineuses pour des systèmes agricoles et alimentaires durables, 2015.

D. Senapathi, M. A. Goddard, W. E. Kunin, and K. C. Baldock, Landscape impacts on pollinator communities in temperate systems: evidence and knowledge gaps, Functional Ecology, vol.31, pp.26-37, 2017.

G. Shackelford, P. R. Steward, T. G. Benton, W. E. Kunin, S. G. Potts et al., Comparison of pollinators and natural enemies: a meta-analysis of landscape and local effects on abundance and richness in crops: Comparison of pollinators and natural enemies, 2013.

, Biological Reviews, vol.88, pp.1002-1021

J. Simon, C. Grignani, A. Jacquet, L. Le-corre, and J. Pagès, Typologie des bilans d'azote, p.165, 2000.
URL : https://hal.archives-ouvertes.fr/hal-00886003

, de divers types d'exploitation agricole: recherche d'indicateurs de fonctionnement, Agronomie, vol.20, pp.175-195

M. B. Soons, M. M. Hefting, E. Dorland, L. P. Lamers, C. Versteeg et al., Nitrogen effects on plant species richness in herbaceous communities are more widespread and stronger than those of phosphorus, Biological Conservation, vol.212, pp.390-397, 2017.

,

J. Spaethe, A. Brockmann, C. Halbig, and J. Tautz, Size determines antennal sensitivity and behavioral threshold to odors in bumblebee workers, Naturwissenschaften, vol.94, pp.733-739, 2007.

,

M. Stang, P. G. Klinkhamer, and E. Van-der-meijden, Size constraints and flower abundance determine the number of interactions in a plant-flower visitor web, Oikos, vol.112, pp.111-121, 2006.

M. Stang, P. G. Klinkhamer, N. M. Waser, I. Stang, and E. Van-der-meijden, Size-specific interaction patterns and size matching in a plant-pollinator interaction web, Annals of Botany, vol.103, pp.1459-1469, 2009.

J. R. Stavert, G. Liñán-cembrano, J. R. Beggs, B. G. Howlett, D. E. Pattemore et al., Hairiness: the missing link between pollinators and pollination, PeerJ, vol.4, 2016.

I. Steffan-dewenter, U. Münzenberg, C. Bürger, C. Thies, and T. Tscharntke, Scaledependent effects of landscape context on three pollinator guilds, Ecology, vol.83, pp.1421-1432, 2002.

B. Ströbel, S. Schmelzle, N. Blüthgen, and M. Heethoff, An automated device for the digitization and 3D modelling of insects, combining extended-depth-of-field and all-side multiview imaging, ZooKeys, vol.759, pp.1-27, 2018.

N. G. Swenson, Functional and Phylogenetic Ecology in R, Use R!, 2014.

S. Taugourdeau, Effects of management and climate on the plant functional diversity related to ecosystem services of permanent grasslands in Europe, 2014.
URL : https://hal.archives-ouvertes.fr/tel-02075327

A. Tibi and O. Thérond, Evaluation des services écosystémiques rendus par les écosystèmes agricoles, 2017.

D. Tilman, P. B. Reich, and J. M. Knops, Biodiversity and ecosystem stability in a decade-long grassland experiment, Nature, vol.441, pp.629-632, 2006.

R. Uyttenbroeck, J. Piqueray, S. Hatt, G. Mahy, and A. Monty, Increasing plant functional diversity is not the key for supporting pollinators in wildflower strips, Ecosystems & Environment, vol.249, pp.144-155, 2017.

C. J. Van-der-kooi, A. G. Dyer, P. G. Kevan, and K. Lunau, Functional significance of the optical properties of flowers for visual signalling, Annals of Botany, 2018.

,

P. C. Van-rijn, J. Kooijman, and F. L. Wäckers, The contribution of floral resources and honeydew to the performance of predatory hoverflies (Diptera: Syrphidae), Biological Control, vol.67, pp.32-38, 2013.

A. D. Vaudo, J. F. Tooker, C. M. Grozinger, and H. M. Patch, Bee nutrition and floral resource restoration, Current Opinion in Insect Science, vol.10, pp.133-141, 2015.

,

D. P. Vázquez, N. P. Chacoff, and L. Cagnolo, Evaluating multiple determinants of the structure of plant-animal mutualistic networks, Ecology, vol.90, pp.2039-2046, 2009.

D. P. Vázquez, W. F. Morris, and P. Jordano, Interaction frequency as a surrogate for the total effect of animal mutualists on plants, Ecology Letters, vol.8, pp.1088-1094, 2005.

P. Veen, R. Jefferson, J. De-smidt, and J. Van-den-straaten, Grasslands in Europe of high nature value, 2009.

W. N. Venables and B. D. Ripley, Modern Applied Statistics with S, Fourth Edition, 2002.

C. Venjakob, A. Klein, A. Ebeling, T. Tscharntke, and C. Scherber, Plant diversity increases spatio-temporal niche complementarity in plant-pollinator interactions, Ecology and Evolution, vol.6, pp.2249-2261, 2016.

S. Villéger, N. W. Mason, and D. Mouillot, New multidimensional functional diversity indices for a multifaceted framework in functional ecology, Ecology, vol.89, pp.2290-2301, 2008.

,

C. Violle, M. Navas, D. Vile, E. Kazakou, C. Fortunel et al., Let the concept of trait be functional! Oikos, vol.116, pp.882-892, 2007.

C. N. Weiner, Diversity and resource choice of flower-visiting insects in relation to pollen nutritional quality and land use (PhD dissertation). Department of Biology, 2016.

C. N. Weiner, A. Hilpert, M. Werner, K. E. Linsenmair, and N. Blüthgen, Pollen amino acids and flower specialisation in solitary bees, Apidologie, vol.41, pp.476-487, 2010.
URL : https://hal.archives-ouvertes.fr/hal-00892082

,

C. N. Weiner, M. Werner, K. E. Linsenmair, and N. Blüthgen, Land-use impacts on plantpollinator networks: interaction strength and specialization predict pollinator declines, Ecology, vol.95, pp.466-474, 2014.

C. N. Weiner, M. Werner, K. E. Linsenmair, and N. Blüthgen, Land use intensity in grasslands: Changes in biodiversity, species composition and specialisation in flower visitor networks, Basic and Applied Ecology, vol.12, pp.292-299, 2011.

P. Wester and K. Lunau, Plant-Pollinator Communication, Advances in Botanical Research, 2017.

, , pp.225-257

P. Westrich, Habitat requirements of central European bees and the problems of partial habitats, Linnean Society Symposium Series, pp.1-16, 1996.

A. Wezel, M. Casagrande, F. Celette, J. Vian, A. Ferrer et al., Agroecological practices for sustainable agriculture. A review, Agron. Sustain. Dev, vol.34, pp.1-20, 2014.
URL : https://hal.archives-ouvertes.fr/hal-01234800

,

H. Wickham, ggplot2: Elegant Graphics for Data Analysis, 2016.

C. Wilcock and R. Neiland, Pollination failure in plants: why it happens and when it matters, Trends in Plant Science, vol.7, pp.270-277, 2002.

B. K. Willcox, M. A. Aizen, S. A. Cunningham, M. M. Mayfield, and R. Rader, Deconstructing pollinator community effectiveness, Current Opinion in Insect Science, vol.21, pp.98-104, 2017.

,

J. B. Wilson, R. K. Peet, J. Dengler, and M. Pärtel, Plant species richness: the world records, Journal of Vegetation Science, vol.23, pp.796-802, 2012.

D. Wintermantel, F. Odoux, J. Chadoeuf, and V. Bretagnolle, Organic farming positively affects honeybee colonies in a flower-poor period in agricultural landscapes, Journal of Applied Ecology, vol.12, 2019.
URL : https://hal.archives-ouvertes.fr/hal-02195533

T. S. Woodcock, B. M. Larson, P. G. Kevan, D. W. Inouye, and K. Lunau, Flies and flowers II: Floral attractants and rewards, Journal of Pollination Ecology, vol.12, pp.63-94, 2014.

K. P. Zulka, Species richness in dry grassland patches of eastern Austria: A multi-taxon study on the role of local, landscape and habitat quality variables. Agriculture, Ecosystems and Environment 182, vol.12, 2014.

A. F. Zuur and E. N. Ieno, A protocol for conducting and presenting results of regression-type analyses, Methods in Ecology and Evolution, vol.7, pp.636-645, 2016.

E. H. Mamdani and S. Assilian, An experiment in linguistic synthesis with a fuzzy logic controller, International Journal of Man-Machine studies, vol.7, issue.1, pp.1-13, 1975.

S. Guillaume and B. Charnomordic, Learning interpretable fuzzy inference systems with FisPro, Information Sciences, vol.181, issue.20, pp.4409-4427, 2011.
URL : https://hal.archives-ouvertes.fr/hal-01318369

C. Coulon-leroy, B. Charnomordic, D. Rioux, M. Thiollet-scholtus, and S. Guillaume, , 2012.

, Prediction of vine vigor and precocity using data and knowledge-based fuzzy inference systems, OENO One, vol.46, issue.3, pp.185-205

C. Annexe, Principal component analysis of soil variables

C. Figure, 1: Factorial plane of the principal component analysis (PCA) of soil variables in Table A.1, generated using the FactoExtra package (Kassambara, 2017) of R software. The first axis (explaining 65.8% of the variance) included soil pH, total nitrogen

A. D. Briscoe and L. Chittka, The evolution of color vision in insects, Annual Review of Entomology, vol.46, issue.1, pp.471-510, 2001.

N. Hempel-de-ibarra, K. V. Langridge, and M. Vorobyev, More than colour attraction: behavioural functions of flower patterns, Current Opinion in Insect Science, vol.12, pp.64-70, 2015.

A. Kassambara, Practical guide to cluster analysis in R: Unsupervised machine learning, 2017.

R. Maia, C. M. Eliason, P. Bitton, S. M. Doucet, and M. D. Shawkey, pavo : an R package for the analysis, visualization and organization of spectral data, Methods in Ecology and Evolution, 2013.

J. P. Renoult, N. Blüthgen, J. Binkenstein, C. N. Weiner, M. Werner et al., The relative importance of color signaling for plant generalization in pollination networks, Oikos, vol.124, issue.3, pp.347-354, 2015.

J. P. Renoult, A. Kelber, and H. M. Schaefer, Colour spaces in ecology and evolutionary biology: Colour spaces in ecology and evolutionary biology, Biological Reviews, vol.92, issue.1, pp.292-315, 2017.

S. Reverté, J. Retana, J. M. Gómez, and J. Bosch, Pollinators show flower colour preferences but flowers with similar colours do not attract similar pollinators, Annals of Botany, vol.118, issue.2, pp.249-257, 2016.

C. J. Van-der-kooi, A. G. Dyer, P. G. Kevan, and K. Lunau, Functional significance of the optical properties of flowers for visual signalling, Annals of Botany, 2018.

I. Figure, 1. Bipartite networks of plant-pollinator interactions sorted by sampling session. A: mid-May

. B:-early-june;-c:-mid-june, Five plant families have distinct colours: Dark blue: Apiaceae; Orange: Asteraceae; Pink: Fabaceae, D: early July; E: early August

, Remaining families are in grey. Plant species are coded as follow: ACHMIL: Achillea millefolium; ACHPTA: Achillea ptarmica; AJUREP: Ajuga reptans; ANTSYL: Anthriscus sylvestris; BELPER: Bellis perennis; CAMRAP: Campanula rapunculus, CENJAC: Centaurea jacea

, CERFON: Ceratium fontanum

, LATPRA: Lathyrus pratensis; LEOAUT: Leontodon autumnalis; LEUVUL: Leucanthemum vulgare; LOTCOR: Lotus corniculatus; LYCFLO: Lychnis flos-cuculi; LYSNUM: Lysimachia nummularia; MEDLUP: Medicago lupulina; MEDMIN: Medicago minima; MYOARV: Myosotis arvensis; ONOVIC: Onobrychis viciifolia; PLALAN: Plantago lanceolata; PLAMED: Plantago media; POTREP: Potentilla reptans; PRUVUL: Prunella vulgaris, GALVER: Galium verum; HERSPH: Heracleum sphondylium; KNAARV: Knautia arvensis

, Ranunculus repens; RHIMIN: Rhinanthus minor; SANMIN : Sanguisorba minor; SENJAC: Jacobaea vulgaris; SENAQU: Jacobaea aquatica; STEGRA: Stellaria graminea; SILSIL: Silaum silaus, RANREP

, TRIFRA: Trifolium fragiferium; TRIPRA: Trifolium pratense; TRIREP: Trifolium repens; VERCHA: Veronica chamaedrys; VICCRA: Vicia cracca; VICHIR: Vicia hirsuta; VICSEP: Vicia sepium. Pollinator orders are coloured following: Pink: Coleoptera, mustard: Diptera, green: Hymenoptera

J. Annexe, List of pollinator species for which body mass has been measured

J. Table, 1: List of all 247 pollinator species sampled and their frequency in the dataset