, Volume 155, Issue 3, pp 469–477 | Cite as

The reproductive assurance benefit of selfing: importance of flower size and population size

Population Ecology - Original Paper


Autonomous selfing can provide reproductive assurance (RA) for flowering plants that are unattractive to pollinators or in environments that are pollen limited. Pollen limitation may result from the breakdown of once-continuous habitat into smaller, more isolated patches (habitat fragmentation) if fragmentation negatively impacts pollinator populations. Here we quantify the levels of pollen limitation and RA among large and small populations of Collinsia parviflora, a wildflower with inter-population variation in flower size. We found that none of the populations were pollen limited, as pollen-supplemented and intact flowers did not differ in seed production. There was a significant effect of flower size on RA; intact flowers (can self) produced significantly more seeds than emasculated flowers (require pollen delivery) in small-flowered plants but not large-flowered plants. Population size nested within flower size did not significantly affect RA, but there was a large difference between our two replicate populations for large-flowered, small populations and small-flowered, large populations that appears related to a more variable pollination environment under these conditions. In fact, levels of RA were strongly negatively correlated with rates of pollinator visitation, whereby infrequent visitation by pollinators yielded high levels of RA via autonomous selfing, but there was no benefit of autonomous selfing when visitation rates were high. These results suggest that autonomous selfing may be adaptive in fragmented habitats or other ecological circumstances that affect pollinator visitation rates.


Autonomous selfing Collinsia parviflora Habitat fragmentation Pollen limitation Reproductive assurance 



We thank E. Fairhurst, S. Gillespie, and E. Jones for field assistance; J. Conner, D. Moeller, S. Kalisz, C. Herlihy, M. Hart, D. Green, and an anonymous reviewer for helpful conversations and/or constructive comments on the manuscript; I. Bercovitz and C. Schwarz for statistical advice; and Capital Regional District Parks, The Nature Conservancy of Canada, British Columbia Provincial Parks, District of Saanich Parks, District of Esquimalt Parks, and TimberWest for access to field sites. This research was supported by a Discovery Grant to E. Elle from the Natural Sciences and Engineering Research Council of Canada. All research complied with the current regulations of landowners and the Canadian Government.


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Copyright information

© Springer-Verlag 2007

Authors and Affiliations

  1. 1.Department of Biological SciencesSimon Fraser UniversityBurnabyCanada

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