Plant-pollination networks and plant invasions

Plant invasions: consequences forplant-pollinator interactions

Ignasi Bartomeus Roig • November 2008 • Universitat Autònoma de Barcelona • CREAF•nacho@creaf.uab.es•Advisor: Montserrat Vilà •

Mack et al.(2000)Ecol Applic

Globalization Increase transport

Mack et al.(2000)Ecol Applic

Globalization Increase transport

21 million flights/day 470 million tones/day

World Bank(2002)

Intentional Unintentional

Mack et al.(2000)Ecol Applic

Globalization Increase transport

21 million flights/day 470 million tones/day

World Bank(2002)

Intentional Unintentional

Mack et al.(2000)Ecol Applic

Globalization Increase transport

21 million flights/day 470 million tones/day

World Bank(2002)

Introduction

Naturalization

Invasion

Invasion process:

Introduction

Naturalization

Invasion

Invasion process:

Introduction

Naturalization

Invasion

Invasion process:

Introduction

Naturalization

Invasion

Invasion process:

Introduction

Naturalization

Invasion

Invasive species characteristics Reproduction system Pre-adaptations

Invaded ecosystem characteristics Empty niches Lack of natural enemies Perturbations

Invasion process:

Introduction

Naturalization

Invasion

Ecological impacts Competition

Economic impacts

Impacts:

Invasion process:

Introduction

Naturalization

Invasion

Ecological impacts Competition

Economic impacts

Impacts:

Invasion process:

Introduction

Naturalization

Invasion

Loss of Biodiversity

Ecological impacts Competition

Economic impacts

Impacts:

Invasion process:

Network

Network

Pollination: Mutualism Ecological service Endangered

Traveset & Richardson(2006)TrEE

Traveset & Richardson(2006)TrEE

New Interactions

Traveset & Richardson(2006)TrEE

New InteractionsMutualistic

networks

Traveset & Richardson(2006)TrEE

New InteractionsMutualistic

networks

Traveset & Richardson(2006)TrEE

Rosmarinus officinalis, Lavandula stoeachs, Cistus spp...

New InteractionsMutualistic

networks

Traveset & Richardson(2006)TrEE

Rosmarinus officinalis, Lavandula stoeachs, Cistus spp...

Bjerkens et al.(2007)Biol Cons

Direct effects

Impacts on native plants

Bjerkens et al.(2007)Biol Cons

Pollinator sharing

Direct effects

Impacts on native plants

Bjerkens et al.(2007)Biol Cons

Visits to natives

Direct effects

Impacts on native plants

Bjerkens et al.(2007)Biol Cons

Visits to natives

Direct effects

Impacts on native plants

Bjerkens et al.(2007)Biol Cons

Visits to natives

Direct effects

Impacts on native plants

Bjerkens et al.(2007)Biol Cons

Visits to natives

Direct effects

Impacts on native plants

Bjerkens et al.(2007)Biol Cons

Pollen transport

Direct effects

Impacts on native plants

Direct effects

CompetitionFacilitationCompetition No effectBjerkens et al.(2007)Biol Cons

Seed set

Impacts on native plants

Direct effects

CompetitionFacilitationCompetition No effectBjerkens et al.(2007)Biol Cons

Chittka & Schurkens(2001)Nature

Seed set

Impacts on native plants

Focal Plant studies:

Direct effects

CompetitionFacilitationCompetition No effectBjerkens et al.(2007)Biol Cons

Moragues & Traveset (2005)Biol Cons

Seed set

Impacts on native plants

Focal Plant studies:

Direct effects

CompetitionFacilitationCompetition No effectBjerkens et al.(2007)Biol Cons

Totland et al.(2006)J BotLarson et al.(2006)Biol Cons Nilsen et al.(2008)Biol Inv

Muñoz & Cavieres (2008)J Ecolet al...

Seed set

Impacts on native plants

Focal Plant studies:

Study species:

South Africa s.XIXFast clonal growthHybrid8-10 cm pollen rich flowersGardening and soil fixation

Carpobrotus aff. acinaciformis

Study species:

South Africa s.XIXFast clonal growthHybrid8-10 cm pollen rich flowersGardening and soil fixation

Carpobrotus aff. acinaciformis

Opuntia stricta

Central America s.XVI1.5 m high5 cm pollen rich flowersOrnamental

Study species:

South Africa s.XIXFast clonal growthHybrid8-10 cm pollen rich flowersGardening and soil fixation

Carpobrotus aff. acinaciformis

Opuntia stricta

Central America s.XVI1.5 m high5 cm pollen rich flowersOrnamental

Impatiens glandulifera

Himalayas s.XX2 m highAnnual4 cm nectar and pollen rich flowers

Study species:

Breeding system & pollen limitation

Effects on plant-pollinators networks

Invasive pollen transfer to native stigmas!

Combined effects of invasion & landscape structure

Objectives:

Breeding system and pollen limitation

I C

Bartomeus I, Vilà M(Submited)

Breeding system and pollen limitation I C

Asexual reproduction Self compatible Generalist

Baker(1967)Evolution

Breeding system and pollen limitation

New Interactions New Interactions

Parcker and Haubenask (2002)Oecologia

I C

Asexual reproduction Self compatible Generalist

Baker(1967)Evolution

Study sites:Breeding system and pollen limitation

Opuntia strictaCarpobrotus aff. acinaciformis

Suehs et al.(2004)Heredity

I C

Study sites:Breeding system and pollen limitation

Opuntia strictaCarpobrotus aff. acinaciformis

Suehs et al.(2004)Heredity

I C

Study sites:Breeding system and pollen limitation

Opuntia strictaCarpobrotus aff. acinaciformis

Suehs et al.(2004)Heredity

I C

Kearns & Inouye(1993)

5 Treatments:

Forced out-crossing Open pollination Anemogamy Facilitated self-pollination Spontaneous self-pollination

40 flowers treatment x 3 site

Breeding system and pollen limitation I C

Breeding system and pollen limitation I C

Site 1Site 2Site 3

Forced Out-crossing

Breeding system and pollen limitation I C

Site 1Site 2Site 3

Forced Out-crossing

Breeding system and pollen limitation I C

Site 1Site 2Site 3

Forced Out-crossing

Breeding system and pollen limitation I C

Site 1Site 2Site 3

Forced Out-crossing

Breeding system and pollen limitation I C

Site 1Site 2Site 3

Forced Out-crossing

Breeding system and pollen limitation I C

Site 1Site 2Site 3

Forced Out-crossing

Breeding system and pollen limitation I C

Site 1Site 2Site 3

Forced Out-crossing

Breeding system and pollen limitation I C

Site 1Site 2Site 3

Forced Out-crossing

Breeding system and pollen limitation

Low self-compatibility They need pollinators

I C

Breeding system and pollen limitation

Low self-compatibility They need pollinators

Slightly pollen limited Hybrid Coleoptera

I C

Breeding system and pollen limitation

Low self-compatibility They need pollinators

Slightly pollen limited Hybrid Coleoptera

I C

Efficient pollinators

Xilocopa violacea & Apis mellifera

Breeding system and pollen limitation

Low self-compatibility They need pollinators

Slightly pollen limited Hybrid Coleoptera

I C

Efficient pollinators

Xilocopa violacea & Apis mellifera

Effects on plant-pollination networks

I C

Bartomeus I, Vilà M & Santamaria L(2008)Oecologia

Effects on plant-pollination networks I C

Effects on plant-pollination networks I C

Effects on plant-pollination networks I C

Effects on plant-pollination networks

Competition with natives at a community level Pollinator sharing Decrease the number of visits to natives Changes in the community structure Nestedness Centrality Strength

I C

Effects on plant-pollination networksOpuntia strictaCarpobrotus aff. acinaciformis

I C

Effects on plant-pollination networks

inix3

50x50

I C

Effects on plant-pollination networks

ini

inix3

x3

50x50

I C

Effects on plant-pollination networks

ini

inix3

x3

50x50

I C

Effects on plant-pollination networks

ini

inix3

x3We sample:All plant species Along all the season

50x50

I C

Effects on plant-pollination networks

Pollinator species

53 species to natives23 species to Carpobrotus (42%)

I C

Effects on plant-pollination networks

Pollinator species

53 species to natives23 species to Carpobrotus (42%)

7 Visits natives

Visits

27 Visits Carpobrotus

I C

Effects on plant-pollination networks

>70% natives increase nº visits in invaded plots (GLMM P<0.02)

Pollinator species

53 species to natives23 species to Carpobrotus (42%)

7 Visits natives

Visits

27 Visits Carpobrotus

I C

Effects on plant-pollination networks

Pollinator species

54 species to natives17 species to Opuntia (31%)

I C

Effects on plant-pollination networks

19% visitsXilocopa violacea

Pollinator species

54 species to natives17 species to Opuntia (31%)

I C

Effects on plant-pollination networks

19% visitsXilocopa violacea

Pollinator species

54 species to natives17 species to Opuntia (31%)

6 Visits natives

Visits

44 Visits Opuntia

I C

Effects on plant-pollination networks

>60% natives decrease nº visits in invaded plots (GLMM P=0.04)

19% visitsXilocopa violacea

Pollinator species

54 species to natives17 species to Opuntia (31%)

6 Visits natives

Visits

44 Visits Opuntia

I C

Effects on plant-pollination networks I C

Effects on plant-pollination networks I C

Effects on plant-pollination networks I C

Effects on plant-pollination networks I C

Effects on plant-pollination networks I C

Effects on plant-pollination networks

Carpobrotus aff. acinaciformis

Plan

ts

Polli

nato

rsI C

Effects on plant-pollination networks

Nestedness

Bascompte et al.(2003)PNAS

I C

Effects on plant-pollination networks

Nestedness

Bascompte et al.(2003)PNAS

I C

Effects on plant-pollination networks

Nestedness

Bascompte et al.(2003)PNAS

Isocline

I C

Effects on plant-pollination networks

Nestedness

Bascompte et al.(2003)PNAS

N= 0.83

Isocline

I C

Effects on plant-pollination networks

Nestedness

Bascompte et al.(2003)PNAS

N= 0.83

Isocline

I C

Effects on plant-pollination networks

Nestedness

Bascompte et al.(2003)PNAS

N= 0.83

Isocline

I C

Effects on plant-pollination networks2. Nestedness

Bascompte, Jordano, Melián and Olesen (2003). PNAS 100: 9383-9387

N=1

N=0.55

N=0.742, P<0.01Olesen & Elberling

Nestedness2. Nestedness

Bascompte, Jordano, Melián and Olesen (2003). PNAS 100: 9383-9387

N=1

N=0.55

N=0.742, P<0.01Olesen & Elberling

2. Nestedness

Bascompte, Jordano, Melián and Olesen (2003). PNAS 100: 9383-9387

N=1

N=0.55

N=0.742, P<0.01Olesen & Elberling

2. Nestedness

Bascompte, Jordano, Melián and Olesen (2003). PNAS 100: 9383-9387

N=1

N=0.55

N=0.742, P<0.01Olesen & Elberling

Null model2. Nestedness

Bascompte, Jordano, Melián and Olesen (2003). PNAS 100: 9383-9387

N=1

N=0.55

N=0.742, P<0.01Olesen & Elberling

I C

Effects on plant-pollination networks2. Nestedness

Bascompte, Jordano, Melián and Olesen (2003). PNAS 100: 9383-9387

N=1

N=0.55

N=0.742, P<0.01Olesen & Elberling

Nestedness

50% more nested than by random No differences in Nestedness for Carpobrotus

Invaded communities more nested than uninvaded for Opuntia.

2. Nestedness

Bascompte, Jordano, Melián and Olesen (2003). PNAS 100: 9383-9387

N=1

N=0.55

N=0.742, P<0.01Olesen & Elberling

2. Nestedness

Bascompte, Jordano, Melián and Olesen (2003). PNAS 100: 9383-9387

N=1

N=0.55

N=0.742, P<0.01Olesen & Elberling

2. Nestedness

Bascompte, Jordano, Melián and Olesen (2003). PNAS 100: 9383-9387

N=1

N=0.55

N=0.742, P<0.01Olesen & Elberling

Null model2. Nestedness

Bascompte, Jordano, Melián and Olesen (2003). PNAS 100: 9383-9387

N=1

N=0.55

N=0.742, P<0.01Olesen & Elberling

I C

Effects on plant-pollination networks2. Nestedness

Bascompte, Jordano, Melián and Olesen (2003). PNAS 100: 9383-9387

N=1

N=0.55

N=0.742, P<0.01Olesen & Elberling

Nestedness

50% more nested than by random No differences in Nestedness for Carpobrotus

Invaded communities more nested than uninvaded for Opuntia.

2. Nestedness

Bascompte, Jordano, Melián and Olesen (2003). PNAS 100: 9383-9387

N=1

N=0.55

N=0.742, P<0.01Olesen & Elberling

2. Nestedness

Bascompte, Jordano, Melián and Olesen (2003). PNAS 100: 9383-9387

N=1

N=0.55

N=0.742, P<0.01Olesen & Elberling

2. Nestedness

Bascompte, Jordano, Melián and Olesen (2003). PNAS 100: 9383-9387

N=1

N=0.55

N=0.742, P<0.01Olesen & Elberling

Null model2. Nestedness

Bascompte, Jordano, Melián and Olesen (2003). PNAS 100: 9383-9387

N=1

N=0.55

N=0.742, P<0.01Olesen & Elberling

I C

Centrality: Degree & Betweenness

Pajek Softweare

Centrality: Degree & Betweenness

High Degree-Centrality

Pajek Softweare

Centrality: Degree & Betweenness

High Betweenness-Centrality

Pajek Softweare

Centrality: Degree & Betweenness

High Betweenness-Centrality

Pajek Softweare

Centrality: Degree & Betweenness

High Betweenness-Centrality

DCCarpobrotus > DCnatives (0.3) (0.09) DCOpuntia > DCnatives (0.38) (0.08)

BCCarpobrotus > BCnatives (0.33) (0.08)BCOpuntia > BCnatives (0.46) (0.06)

Pajek Softweare

Effects on plant-pollination networks

Opuntia stricta

Plan

ts

Polli

nato

rs

j i

I C

Bascompte et al.(2006)Science

Effects on plant-pollination networks

Opuntia stricta

Plan

ts

Polli

nato

rs

j i

dji = nºVji/nº VjDependence of j on i:

I C

Bascompte et al.(2006)Science

Effects on plant-pollination networks

Opuntia stricta

Plan

ts

Polli

nato

rs

j i

dji = nºVji/nº VjDependence of j on i:Si = ∑ djiStrength of i:

I C

Bascompte et al.(2006)Science

Effects on plant-pollination networks

Opuntia stricta

Plan

ts

Polli

nato

rs

j i

SCarpobrotus > Snatives (6.5) (2.2) SOpuntia > Snatives (8.1) (2.1)

Strength

dji = nºVji/nº VjDependence of j on i:Si = ∑ djiStrength of i:

I C

Bascompte et al.(2006)Science

Effects on plant-pollination networks

Both invaders are generalists: Nº Pollinators Nº of visits Position in the network

I C

Effects on plant-pollination networks

Different effects on plant comunity: Increase visits in Carpobrotus plots Decrease visits in Opuntia plots

I C

Invasive pollen transfer to native stigmas

I C

Bartomeus I, Bosch J & Vilà M (2008) Annals of Botany

CompetitionFacilitationCompetition No effect

Invasive pollen transfer to native stigmas I C

CompetitionFacilitationCompetition No effect

Invasive pollen transfer to native stigmas I C

Invasive pollen transfer to native stigmas

Shared pollinators

I C

Invasive pollen transfer to native stigmas

Pollen loads in pollinator bodies Conspecific pollen Invasive > heterospecific native pollen

Shared pollinators

I C

Invasive pollen transfer to native stigmas

Pollen loads in pollinator bodies Conspecific pollen Invasive > heterospecific native pollen

Pollen deposition in native plant stigmas

Proportion of invasive pollen

Shared pollinators

I C

Effects on plant-pollination networks

Carpobrotus aff. acinaciformis

I C

Carpobrotus

39% plant cover 36% of visits

Fuchsine stained gelatine

Invasive pollen transfer to native stigmas I C

Carpobrotus

39% plant cover 36% of visits

Fuchsine stained gelatine

5 Plant species 49% plant cover

51% of visits

10 pollinators (5 bees, 5 beetles)

76% of visits

Invasive pollen transfer to native stigmas I C

Carpobrotus

39% plant cover 36% of visits

Fuchsine stained gelatine

30 stigmas x species

15 pollinators x interaction

5 Plant species 49% plant cover

51% of visits

10 pollinators (5 bees, 5 beetles)

76% of visits

Invasive pollen transfer to native stigmas I C

Oxythyrea funestaCistus albidus

Invasive pollen transfer to native stigmas I C

Oxythyrea funestaCistus albidus

Invasive pollen transfer to native stigmas

Andrena sp.Cistus salvifolius

I C

Oxythyrea funestaCistus albidus

Invasive pollen transfer to native stigmas

Andrena sp.Cistus salvifolius

Cistus monspeliensis

I C

Oxythyrea funestaCistus albidus

Invasive pollen transfer to native stigmas

Andrena sp.Cistus salvifolius

Cistus monspeliensis

Lavandula stoechas Eucera sp

I C

Oxythyrea funestaCistus albidus

Invasive pollen transfer to native stigmas

Andrena sp.Cistus salvifolius

Cistus monspeliensis

Lavandula stoechas Eucera sp

I C

Sonchus tenerrimus Criptocephalus sp

Invasive pollen transfer to native stigmas

Apis melifera Bombus terrestris

Andrena sp.

Anthidium sticticum

Halictus gemmeus

Oxythyrea funesta

Cryptocephalus spMordella sp

Oedemera spp.Psilothrix sp

I C

Invasive pollen transfer to native stigmas

Apis melifera Bombus terrestris

Andrena sp.

Anthidium sticticum

Halictus gemmeus

Oxythyrea funesta

Cryptocephalus spMordella sp

Oedemera spp.Psilothrix sp

CistusLavandula

Carpobrotus

I C

Invasive pollen transfer to native stigmas

Apis melifera Bombus terrestris

Andrena sp.

Anthidium sticticum

Halictus gemmeus

Oxythyrea funesta

Cryptocephalus spMordella sp

Oedemera spp.Psilothrix sp

We counted 139 063 pollen grains Average: 3 pollen species per individual

CistusLavandula

Carpobrotus

I C

Invasive pollen transfer to native stigmas

Apis melifera Bombus terrestris

Andrena sp.

Anthidium sticticum

Halictus gemmeus

Oxythyrea funesta

Cryptocephalus spMordella sp

Oedemera spp.Psilothrix sp

We counted 139 063 pollen grains Average: 3 pollen species per individual

CistusLavandula

Carpobrotus

73% carried invasive pollen

I C

Invasive pollen transfer to native stigmas

Apis melifera Bombus terrestris

Andrena sp.

Anthidium sticticum

Halictus gemmeus

Oxythyrea funesta

Cryptocephalus spMordella sp

Oedemera spp.Psilothrix sp

We counted 139 063 pollen grains Average: 3 pollen species per individual

CistusLavandula

Carpobrotus

73% carried invasive pollen

23% of pollen was invasive

I C

Main Results

Invasive pollen transfer to native stigmas I C

Main Results

Invasive pollen transfer to native stigmas I C

Main Results

Invasive pollen transfer to native stigmas I C

Main Results

Invasive pollen transfer to native stigmas I C

2 pollinators (bees): Dominant heterospecific > invasive (p < 0.001)6 pollinators:Dominant heterospecific ∼ invasive2 pollinators (beetles): Invasive > dominant heterospecific (p < 0.006)

Invasive vs. heterospecific native pollenInvasive pollen transfer to native stigmas I C

2 pollinators (bees): Dominant heterospecific > invasive (p < 0.001)6 pollinators:Dominant heterospecific ∼ invasive2 pollinators (beetles): Invasive > dominant heterospecific (p < 0.006)

Invasive vs. heterospecific native pollenInvasive pollen transfer to native stigmas I C

All stigmas were covered by pollen Average: 2 pollen species

per stigma

Invasive pollen transfer to native stigmas

36% invasive pollen

stigmas

I C

All stigmas were covered by pollen Average: 2 pollen species

per stigma

Invasive < heterospecific < conspecific (χ2, p < 0.0001)

Invasive pollen transfer to native stigmas

36% invasive pollen

stigmas

I C

1) pollinator species sharing

Invasive pollen transfer to native stigmas I C

1) pollinator species sharing

2) effective pollen transfer

Invasive pollen transfer to native stigmas I C

1) pollinator species sharing

3) low invasive pollen loads

2) effective pollen transfer

Invasive pollen transfer to native stigmas I C

1) pollinator species sharing

4) lower invasive pollen deposition

3) low invasive pollen loads

2) effective pollen transfer

Invasive pollen transfer to native stigmas I C

1) pollinator species sharing

4) lower invasive pollen deposition

3) low invasive pollen loads

2) effective pollen transfer

Invasive pollen transfer to native stigmas

...Floral constancy, morphology & temporal presentation

I C

Combined effects of invasion & landscape structure

I C

Bartomeus I, Vilà M & Setffan-Dewenter I(In preparation)

Combined effects of invasion & landscape structure I C

Combined effects of invasion & landscape structure I C

Combined effects of invasion & landscape structure

Invasion

I C

Landscape context

Combined effects of invasion & landscape structure

Invasion

I C

Combined effects of invasion & landscape structure I C

Steffan-Dewenter et al.(2002)Ecology

Combined effects of invasion & landscape structure I C

Steffan-Dewenter et al.(2002)Ecology

Combined effects of invasion & landscape structure I C

Steffan-Dewenter et al.(2002)Ecology

Combined effects of invasion & landscape structure I C

Steffan-Dewenter et al.(2002)Ecology

Combined effects of invasion & landscape structure I C

Westphal et al.(2003)Ecol Lett

Combined effects of invasion & landscape structure I C

Westphal et al.(2003)Ecol Lett

Combined effects of invasion & landscape structure I C

Westphal et al.(2003)Ecol Lett

X 14 sites in a landscape gradientCombined effects of invasion & landscape structure

17% of natural cover71% of natural cover

GrasslandAgricultural fields

Human activity area

Landscape sites at 3000 m radii.

Forest

I C

X 14 sites in a landscape gradientCombined effects of invasion & landscape structure

17% of natural cover71% of natural cover

GrasslandAgricultural fields

Human activity area

Landscape sites at 3000 m radii.

Forest

I C

100m 100m

Before Impatiens flowering period

Raphanus sativus pots

Impatiens stands

X 14 sites in a landscape gradient

100m 100m

During Impatiens flowering peak

Combined effects of invasion & landscape structure

17% of natural cover71% of natural cover

GrasslandAgricultural fields

Human activity area

Landscape sites at 3000 m radii.

Forest

I C

100m 100m

Before Impatiens flowering period

Raphanus sativus pots

Impatiens stands

Log (proportion of agricultural land cover)

Log

(num

ber

of b

umbl

ebee

s visit

s)

0

1

2

21 1.5

Combined effects of invasion & landscape structure

Before Impatiens floweringDuring Impatiens flowering

R2= 0.25; p< 0.003

I C

Log (proportion of agricultural land cover)

Log

(num

ber

of b

umbl

ebee

s visit

s)

0

1

2

21 1.5

Combined effects of invasion & landscape structure

Before Impatiens floweringDuring Impatiens flowering

R2= 0.25; p< 0.003

I C

a a

b

c

0

5

10

15

20

25

30

35

40

Before /Non-invaded

Before /Invaded

During /Non-invaded

During /Invaded

visits to natives

Numbe

r of

visi

ts t

o th

e co

mmun

ity

b

visits to invader

Combined effects of invasion & landscape structure I C

a a

b

c

0

5

10

15

20

25

30

35

40

Before /Non-invaded

Before /Invaded

During /Non-invaded

During /Invaded

visits to natives

Numbe

r of

visi

ts t

o th

e co

mmun

ity

b

visits to invader

Combined effects of invasion & landscape structure I C

a a

b

c

0

5

10

15

20

25

30

35

40

Before /Non-invaded

Before /Invaded

During /Non-invaded

During /Invaded

visits to natives

Numbe

r of

visi

ts t

o th

e co

mmun

ity

b

visits to invader

Combined effects of invasion & landscape structure I C

0

5

10

15

20

25

30

35

40

45

50

% Fruit setNº Visits

Raphanus pots

Combined effects of invasion & landscape structure

Before /Non-invaded

Before /Invaded

During /Non-invaded

During /Invaded

I C

Nº V

isits

/%

Fru

it se

t

0

5

10

15

20

25

30

35

40

45

50

% Fruit setNº Visits

Raphanus pots

Combined effects of invasion & landscape structure

Before /Non-invaded

Before /Invaded

During /Non-invaded

During /Invaded

I C

Nº V

isits

/%

Fru

it se

t

Combined effects of invasion & landscape structure I C

Combined effects of invasion & landscape structure

1) Social bees increase in agricultural areas before

the invasive plant flowering2) No effect on wild bees

I C

Combined effects of invasion & landscape structure

4) Native plants do not decrease visitation, nor seed set

3) Impatiens attracts mainly bumblebees

1) Social bees increase in agricultural areas before

the invasive plant flowering2) No effect on wild bees

I C

Combined effects of invasion & landscape structure

Impatiens mask off the landscape effect

4) Native plants do not decrease visitation, nor seed set

3) Impatiens attracts mainly bumblebees

1) Social bees increase in agricultural areas before

the invasive plant flowering2) No effect on wild bees

I C

CompetitionFacilitation

No effect

Conclusions

CompetitionFacilitation

No effect

Carpobrotus

Conclusions

CompetitionFacilitation

No effectImpatiens

Conclusions

CompetitionFacilitation

No effect

Opuntia

Conclusions

CompetitionFacilitation

No effect mask off landscape contextImpatiens

Conclusions

CompetitionFacilitation

No effect mask off landscape contextImpatiens

Conclusions

CompetitionFacilitation

No effect mask off landscape contextImpatiens

Conclusions

Take home message

Plant-pollinator networks are complex &the invasion outcome is difficult to predict.

However, invasive plants cause significant changes on the networks.

Thank you for your attentionAnd special Thanks to collaborators: Montse Vilà, Jordi Bosch, Ingolf Steffan-Dewenter; Lab colleges: Jara Andreu, Nuria Gasso, Salva Blanch, Belén Sanchez and CREAF friends.