Abstract
Invasive alien plants can compete with native plants for resources, and may ultimately decrease native plant diversity and/or abundance in invaded sites. This could have consequences for native mutualistic interactions, such as pollination. Although invasive plants often become highly connected in plant-pollinator interaction networks, in temperate climates they usually only flower for part of the season. Unless sufficient alternative plants flower outside this period, whole-season floral resources may be reduced by invasion. We hypothesized that the cessation of flowering of a dominant invasive plant would lead to dramatic, seasonal compositional changes in plant-pollinator communities, and subsequent changes in network structure. We investigated variation in floral resources, flower-visiting insect communities, and interaction networks during and after the flowering of invasive Rhododendron ponticum in four invaded Irish woodland sites. Floral resources decreased significantly after R. ponticum flowering, but the magnitude of the decrease varied among sites. Neither insect abundance nor richness varied between the two periods (during and after R. ponticum flowering), yet insect community composition was distinct, mostly due to a significant reduction in Bombus abundance after flowering. During flowering R. ponticum was frequently visited by Bombus; after flowering, these highly mobile pollinators presumably left to find alternative floral resources. Despite compositional changes, however, network structural properties remained stable after R. ponticum flowering ceased: generality increased, but quantitative connectance, interaction evenness, vulnerability, H'2 and network size did not change. This is likely because after R. ponticum flowering, two to three alternative plant species became prominent in networks and insects increased their diet breadth, as indicated by the increase in network-level generality. We conclude that network structure is robust to seasonal changes in floral abundance at sites invaded by alien, mass-flowering plant species, as long as alternative floral resources remain throughout the season to support the flower-visiting community.
Abstract from the paper’s OpenAlex record; open copy licensed cc-by. Read at the source ↗
The text the model read, with the source record’s inline markup (italics, sub- and superscripts) rendered and its character entities decoded; quote offsets refer to the raw text.
Claims 8
Claim · model-written summary
Floral resources decreased significantly after R. ponticum flowered, with variation among sites.
- Taxon
- Rhododendron ponticum
_Rhododendron_ponticum_-_flower_bud.jpg?width=60)
Rhododendron ponticumt0 - Outcome
- Floral resourcese0
- Direction
- decreasede0
- Qualifier
- magnitude of the decrease varied among sitese0
Organisms pictured · Representative pictures of the matched species, not figures from the paper.
_Rhododendron_ponticum_-_flower_bud.jpg?width=500)
Verbatim
t0“Rhododendron ponticum”
e0“Floral resources decreased significantly after R. ponticum flowering, but the magnitude of the decrease varied among sites”
Claim · model-written summary
Insect abundance and richness did not vary between flowering and postflowering periods.
- Taxon
- Rhododendron ponticumRhododendron ponticumt0
- Outcome
- insect abundance nor richnesse0
- Direction
- Neithere0
Organisms pictured · Representative pictures of the matched species, not figures from the paper.
Verbatim
t0“Rhododendron ponticum”
e0“Neither insect abundance nor richness varied between the two periods (during and after R. ponticum flowering)”
Claim · model-written summary
Insect community composition differed after flowering, mainly as Bombus abundance fell significantly.
- Taxon
- Rhododendron ponticumRhododendron ponticumt0
- Outcome
- Bombus abundancee0
- Direction
- reductione0
BombusOrganisms pictured · Representative pictures of the matched species, not figures from the paper.
Verbatim
t0“Rhododendron ponticum”
e0“insect community composition was distinct, mostly due to a significant reduction in Bombus abundance after flowering”
Claim · model-written summary
Bombus visited R. ponticum frequently during its flowering.
- Taxon
- Rhododendron ponticumRhododendron ponticumt0
- Outcome
- frequently visitede0
Organisms pictured · Representative pictures of the matched species, not figures from the paper.
Verbatim
t0“Rhododendron ponticum”
e0“During flowering R. ponticum was frequently visited by Bombus”
Claim · model-written summary
Network generality increased after R. ponticum flowering ceased.
- Taxon
- Rhododendron ponticumRhododendron ponticumt0
- Outcome
- generalitye0
- Direction
- increasede0
Organisms pictured · Representative pictures of the matched species, not figures from the paper.
Verbatim
t0“Rhododendron ponticum”
e0“generality increased”
Claim · model-written summary
Connectance, interaction evenness, vulnerability, H2 and network size did not change after flowering.
- Taxon
- Rhododendron ponticumRhododendron ponticumt0
- Outcome
- quantitative connectance, interaction evenness, vulnerability, H'2 and network sizee0
- Direction
- did not changee0
Organisms pictured · Representative pictures of the matched species, not figures from the paper.
Verbatim
t0“Rhododendron ponticum”
e0“quantitative connectance, interaction evenness, vulnerability, H'2 and network size did not change”
Claim · model-written summary
Two to three alternative plant species became prominent in networks after R. ponticum flowering.
- Taxon
- Rhododendron ponticumRhododendron ponticumt0
- Outcome
- alternative plant species became prominent in networkse0
- Value
- two to threee0
Organisms pictured · Representative pictures of the matched species, not figures from the paper.
Verbatim
t0“Rhododendron ponticum”
e0“after R. ponticum flowering, two to three alternative plant species became prominent in networks”
Claim · model-written summary
Insects broadened their diet after flowering, as indicated by increased network generality.
- Taxon
- Rhododendron ponticumRhododendron ponticumt0
- Outcome
- diet breadthe0
- Direction
- increasede0
Organisms pictured · Representative pictures of the matched species, not figures from the paper.
Verbatim
t0“Rhododendron ponticum”
e0“insects increased their diet breadth, as indicated by the increase in network-level generality”