The projected alterations to climate in the High Arctic are likely to result in changes to the short
growing season, particularly with varying predicted effects on winter snowfall, the timing of summer
snowmelt and air temperatures. These changes are likely to affect the phenology of interacting species
in a variety of ways, but few studies have investigated the effects of combined climate drivers on plant–
pollinator interactions in the High Arctic. In this study, we alter the timing of flowering phenology
using a field manipulation experiment in which snow depth is increased using snow fences and
temperatures are enhanced by open-top chambers(OTCs). We used this experiment to quantify the
combined effects of treatments on the flowering phenology of six dominant plant species(Dryas
octopetala, Cassiope tetragona, Bistorta vivipara, Saxifraga oppositifolia, Stellaria crassipes and
Pedicularis hirsuita), and to simulate differing responses to climate between plants and pollinators in a
subset of plots. Flowers were counted regularly throughout the growing season of 2015, and insect
visitors were caught on flowers during standardised observation sessions. As expected, deep snow
plots had delayed snow melt timing and this in turn delayed the first and peak flowering dates of the
plants and shortened the prefloration period overall. The OTCs counteracted the delay in first and
peak flowering to some extent. There was no effect of treatment on length of flowering season,
although for all variables there were species-specific responses. The insect flower–visitor community
was species poor, and although evidence of disruption to phenological overlaps was not found, the
results do highlight the vulnerability of the plant–pollinator network in this system with differing
phenological shifts between insects and plants and reduced visitation rates to flowers in plots with
deep snow