natasha de manincor university of lille

European

workshop

Atlantic biogeographicalcalcareous grasslands

September 18th – 19th 2019

Rouen, France

Plant-pollinator network diversity in calcareous grasslands

Natasha de Manincor

University of Lille

European

workshop



Rouen, France

Calcareous grasslands

• Semi-natural habitats

• High diversity of both plant and insect species, variety of rare species

• High proportion entomophilous species

• Greatest amount of floral resources, i.e. plant nectar per unit area

WallisDeVries et al. 2002; Butaye et al. 2005; Baude et al. 2016

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workshop



Rouen, France

Calcareous grasslands

Ecological function → Pollination

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workshop



Rouen, France

Pollinators and insects decline

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workshop



Rouen, France

New challenge for Natural reserves

Preserving species interactionsConservation of the ecological function

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workshop



Rouen, France

Study goals

• Species diversity

• Interactions diversity

• Characterize plant-pollinator networks

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Rouen, France

Plant-pollinator networks

Social network

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Direct interaction

Indirect interactions

Indirect interactions

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workshop



Rouen, France

Material and Methods• Fieldwork sessions:

from April to October (once a month)

for two consecutives years (2016 and 2017 )

• Three regions, 6 calcareous grasslands (CEN NPdC, Picardie and Normandie)

Hauts-de-France

Normandie

Occitanie

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workshop



Rouen, France

Les Falaises(Giverny)

Chateau Gaillard(Les Andelys)

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Rouen, France

BOTANIC INVENTORY

POLLINATORSAMPLING

Wild bees Hoverflies

Flowering species

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workshop



Rouen, France

BOTANIC INVENTORY

Flowering species

POLLEN ATLAS

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workshop



Rouen, France

Plant-pollinator interactions

Pollinator diversity

ACTIVESAMPLING

PASSIVESAMPLING

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Pollen Scattered

Specializedstructures

Pollen Collected

Nest

Pollination event

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workshop



Rouen, France

Insect preparation and taxonomic identification at the species level by experts (C. Vanappelghem, D. Genoud, M. Aubertand many others)

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Rouen, France

Results

20162017

Hauts-de-FranceNormandieOccitanie

94 species92 species221 species

288 plant species overall (2016 and 2017)

Only 9% of species were shared among the 3 regions

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15702 sampled insects overall

20162017

318 bee species (33% of the French bee fauna)

109 hoverfly species (20% of the French hoverfly fauna)

166 species221 species340 species

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Rouen, France

Hauts-de-France

Normandie

Occitanie

2016 2017

Differences in species richness among regions & along the season

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Rouen, France

Important species turnover along the season, with most species showing short phenologies

Hauts-de-France

Normandie

Occitanie

Nb of months occurence

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Rouen, France

timeApril October

Anacamptispyramidalis

Bombuslapidarius

Andrenadorsata

Euphorbiaesula

Hieraciumpilosella

Panurguscalcaratus

Picrishieracioides

Lasioglossuminterruptum

Anthericumramosum

Osmiarufohirta

Campanularotundifolia

Chelostomacampanularum

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Bombuspratorum

Andrenagravida

Helianthemumapenninum

Polygalacalcarea

Helianthemumoelandicum

Hieraciumpilosella

It is therefore essential not only to focus on the rare species, but to consider the entire community and the interactions among species.

Anacamptis pyramidalis

Protected species


Anthericumramosum

Centaureascabiosa

Ononisnatrix

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Château Gaillard : a case of study• Nb insect species: 178

• Nb plant species: 77

• Nb recorded interactions: 1724

• Insect species higher nb interactions (> 100):• Lasioglossum interruptum (n = 183)• Lasioglossum morio (n = 200)• Bombus pascuorum (n = 210)• Bombus lapidarius (n = 213)

• Plant species higher nb interactions (> 100):• Centaurea scabiosa (n = 109)• Helianthemum apenninum (n = 118)• Leontodon hispidus (n = 131)• Hieracium pilosella (n = 160)• Anthericum ramosum (n = 214)• Scabiosa columbaria (n = 230)


Anthericumramosum

Bombuslapidarius


Generalist speciesLong phenology

Short phenology

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Rouen, France

• Flowering period during the richest months / year

• Short phenology (3 months)• High abundance

• Early phenology• Short phenology

(2 months)• Important

resource for many (early) pollinators (25 different species)

April October


Anthericumramosum

Scabiosacolumbaria

Leontodonhispidus

• Longer phenology(from June untilOctober)

• Important at the end of the season(responsable for halfof interactions)

Low priority No priority No priorityPDG 2013-2017

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Rouen, France

• Early phenology• Long phenology (from April to August)• Most visited plant species in Chateau Gaillard: 37

different pollinator species

April October

No priority, no threaten species, no patrimonial interestPDG 2013-2017

Hieraciumpilosella

Andrena humilisOligolectic speciesSolitary speciesUnivoltine

Colletes similisOligolectic speciesSolitary speciesUnivoltine

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workshop



Rouen, France

Perspectives• Management plans need to be adapted both to

maintain biodiversity and ecological functions;

• Management plans need to be adapted followingthe species phenology. For example: an earlygrazing or in the richest months can compromise access to resources for pollinators;

• It is also necessary to preserve the “common species” that are important for pollinators and indirectly (via indirect interactions) for the maintenance of rare species

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workshop



Rouen, France

Thanks for your attention

[email protected]

Thanks also to all the bees and hoverflies that offered their lives for the good of Science!

Thanks also to Emmanuel Vochelet and CEN Normandie for the access to the study sites

natasha de manincor university of lille

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