Limits...
Space, time and aliens: charting the dynamic structure of Galápagos pollination networks.

Traveset A, Chamorro S, Olesen JM, Heleno R - AoB Plants (2015)

Bottom Line: We found that the pollination network structure was rather consistent between the two islands, but differed across habitats and seasons.It is thus likely that, in spite of the overall weak effect we found of alien plant invasion on pollination network structure, these introduced species influence the reproductive success of native ones, and by doing so, they affect the functioning of the community.This certainly deserves further investigation.

View Article: PubMed Central - PubMed

Affiliation: Laboratorio Internacional de Cambio Global (LINC-Global), Institut Mediterrani d'Estudis Avançats (CSIC-UIB), C/Miquel Marqués 21, 07190-Esporles, Mallorca, Balearic Islands, Spain atraveset@imedea.csic-uib.es.

No MeSH data available.


Relationship between the level of invasion (i.e. fraction of alien flowers out of all flowers in the site) and the level of network specialization H′2 found during the 2 years of the study. Data from the two islands and the three habitats are pooled. The association is marginally significant in the two cases (t = 1.9, P = 0.07 and t = 2.14, P = 0.06, in 2010 and 2011, respectively).
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PLV068F3: Relationship between the level of invasion (i.e. fraction of alien flowers out of all flowers in the site) and the level of network specialization H′2 found during the 2 years of the study. Data from the two islands and the three habitats are pooled. The association is marginally significant in the two cases (t = 1.9, P = 0.07 and t = 2.14, P = 0.06, in 2010 and 2011, respectively).

Mentions: The fraction of realized interactions out of all possible in the network (connectance) did not vary either between islands, habitats or seasons (Fig. 2), and it was not influenced by the level of invasion (all P > 0.05). The same result was found for interaction asymmetry, which indicates the difference in the dependence of animals on plants and vice versa. Interaction evenness, which measures the uniformity in the distribution of interaction frequencies differed only across habitats, i.e. habitat was the only factor included in the best model (χ2 = 0.05, d.f. = 2, P = 0.02). The humid zone showed a more even frequency of interactions than the arid and the transition zones (Fig. 2). Interaction evenness was also independent of invasion level (χ2 = 1.90, d.f. = 1, P = 0.17). In contrast, the best model for complementary specialization included only invasion level (χ2 = 0.11, d.f. = 1, P = 0.057); a high fraction of alien flowers in the community was positively associated with higher (Fig. 3), i.e. with higher levels of selectiveness or niche differentiation, implying that species tended to visit (pollinators) or be visited (plants) by partners more frequently than expected from the relative abundances of the latter.Figure 3.


Space, time and aliens: charting the dynamic structure of Galápagos pollination networks.

Traveset A, Chamorro S, Olesen JM, Heleno R - AoB Plants (2015)

Relationship between the level of invasion (i.e. fraction of alien flowers out of all flowers in the site) and the level of network specialization H′2 found during the 2 years of the study. Data from the two islands and the three habitats are pooled. The association is marginally significant in the two cases (t = 1.9, P = 0.07 and t = 2.14, P = 0.06, in 2010 and 2011, respectively).
© Copyright Policy - creative-commons
Related In: Results  -  Collection

License
Show All Figures
getmorefigures.php?uid=PMC4522039&req=5

PLV068F3: Relationship between the level of invasion (i.e. fraction of alien flowers out of all flowers in the site) and the level of network specialization H′2 found during the 2 years of the study. Data from the two islands and the three habitats are pooled. The association is marginally significant in the two cases (t = 1.9, P = 0.07 and t = 2.14, P = 0.06, in 2010 and 2011, respectively).
Mentions: The fraction of realized interactions out of all possible in the network (connectance) did not vary either between islands, habitats or seasons (Fig. 2), and it was not influenced by the level of invasion (all P > 0.05). The same result was found for interaction asymmetry, which indicates the difference in the dependence of animals on plants and vice versa. Interaction evenness, which measures the uniformity in the distribution of interaction frequencies differed only across habitats, i.e. habitat was the only factor included in the best model (χ2 = 0.05, d.f. = 2, P = 0.02). The humid zone showed a more even frequency of interactions than the arid and the transition zones (Fig. 2). Interaction evenness was also independent of invasion level (χ2 = 1.90, d.f. = 1, P = 0.17). In contrast, the best model for complementary specialization included only invasion level (χ2 = 0.11, d.f. = 1, P = 0.057); a high fraction of alien flowers in the community was positively associated with higher (Fig. 3), i.e. with higher levels of selectiveness or niche differentiation, implying that species tended to visit (pollinators) or be visited (plants) by partners more frequently than expected from the relative abundances of the latter.Figure 3.

Bottom Line: We found that the pollination network structure was rather consistent between the two islands, but differed across habitats and seasons.It is thus likely that, in spite of the overall weak effect we found of alien plant invasion on pollination network structure, these introduced species influence the reproductive success of native ones, and by doing so, they affect the functioning of the community.This certainly deserves further investigation.

View Article: PubMed Central - PubMed

Affiliation: Laboratorio Internacional de Cambio Global (LINC-Global), Institut Mediterrani d'Estudis Avançats (CSIC-UIB), C/Miquel Marqués 21, 07190-Esporles, Mallorca, Balearic Islands, Spain atraveset@imedea.csic-uib.es.

No MeSH data available.