Nocturnal and diurnal contribution to pollination in urban community gardens

Nicole Elise Wonderlin and Peter J. T. White, Entomology, Michigan State University, East Lansing, MI, Nicole Elise Wonderlin, Ecology, Evolution, Behavior Program, Michigan State University, East Lansing, MI, Peter J. T. White, Lyman Briggs College, Michigan State University, East Lansing, MI

Background/Question/Methods
Pollination is a significant ecosystem function. Until recently, most pollination research has focused on diurnal (day active) pollinators. However, nocturnal plant visitors, such as moths, may represent a significant and underreported portion of plant-pollinator interactions. To explore the contribution of diurnal and nocturnal pollinators to plant reproductive success, we conducted a floral-bagging experiment in urban community gardens in Ingham County, Michigan. A Michigan-native flower species, Eupatorium perfoliatum, was divided into four treatments and exposed to diurnal, nocturnal, all, or no pollinators using mesh pollinator exclusion bagging. Using seed set and viability analysis, we compared reproductive success between all treatments.
Results/Conclusions
Plants exposed to all, diurnal, and nocturnal pollinators had significantly higher seed weights, a measure often used as a proxy for reproductive success, than those that remained closed (ANOVA F=23.1, p<0.01). The similarities between the open to all pollinator, open to diurnal pollinator, and open to nocturnal pollinator treatments indicate a redundant, rather than additive set of pollination interactions. Redundant pollination services may safeguard environments that are suffering pollinator population declines, like urban environments, from the negative effects of pollinator loss like reduced seed and fruit production and biodiversity reduction.