The Effect Of Flowering Synchrony And Floral Display On The Reproduction Of A Gynodioecious Alpine Cushion Plant, Silene Acaulis (Caryophyllaceae)

We tested whether floral display and flowering synchrony with conspecific neighbors affected the reproductive success of each sex in a gynodioecious species, Silene acaulis. Furthermore, we explored how varying the spatial scale and type (which sexes included in the neighborhood) of the neighborhoods used to define synchrony affected its correlation with fruit production. We observed four sites of this alpine cushion plant throughout two flowering seasons at Niwot Ridge, Colorado. Female plants had significantly higher raw fruit production and per-flower fruit set than hermaphrodites. The total number of flowers produced by an individual was positively correlated with fruit set, suggesting that individuals that produce more flowers are more likely to be pollinated. We found a positive correlation between synchrony of flowering and raw fruit production, however the mechanism behind that relationship is still unknown. Varying the spatial scale or type of neighborhood by which we calculated synchrony scores had no effect on synchrony’s relationship with fruit production, however we recommend that future studies on the effects of flowering synchrony carefully consider the effect of neighborhood size. Understanding the factors that influence the reproductive success of a gynodioecious population clarifies the processes that may influence populations’ responses to climate change.