Data from: Assessment of pollination ecology of two understudied native mustards and the potential for interference from invasive garlic mustard

Comparing pollinator visitation rates and identity between two native
mustards (Cardamine concatenata and Cardamine diphylla) and one invasive
mustard (Alliaria petiolata). These native mustards are of interest for
two reasons. First, they host rare, specialist insects (Pieris
virginiensis and Phyllotreta bipustulata). Second, because C. concatenata
and C. diphylla have a short phenological window for seasonal development
and reproduction, they are at increased risk for mutualism disruption via
global change pressures, such as potential pollination disruption from A.
petiolata. In this study, we aimed to establish the rate of pollinator
visitation as well as pollinator identity for each mustard using sites at
the Holden Arboretum in Kirtland, Ohio, where these mustards co-occur. We
established randomized 1m2 quadrats in which we counted the number of open
flowers of each mustard species. We then recorded the number of visits and
visually grouped pollinators into morphotype groupings. We also
established collection quadrats in the same manner and captured all
pollinators that entered the quadrat over the sampling period. These
specimens were preserved and identified to the lowest taxonomic level
possible in the lab. We recorded fourteen unique pollinator taxa at our
study sites. We established that C. concatenata flowering phenology does
not overlap with A. petiolata flowering and therefore is not at high risk
of experiencing pollination interference. C. diphylla flowering, however,
overlapped with A. petiolata flowering. C. diphylla and A. petiolata
shared seven of the fourteen taxa as pollinators, four of which visited
these species non-discriminately (i.e., the rate of visitation for these
taxa was not significantly different between A. petiolata and C.
diphylla). Because pollinators are shared and visitation rates are
similar, C. diphylla could potentially be experiencing decreased
reproductive success where it co-occurs with A. petiolata.