Assistant Professor University of Maryland College Park, Maryland, United States
Serpentine Grasslands (SGs) are characterized by prairie-like appearance and shallow, rocky, and heavy-metal-rich soils. Fragments of this habitat are scattered among the Appalachian Mountains, particularly across Maryland and Pennsylvania. Although they represent fascinating systems that could become ecological and evolutionary models, very little is known about them. Focusing on a number of SG areas from Maryland, in the present study we aim to i) identify insect flower visitors that may act as pollinators, ii) characterize the taxonomic composition and adult seasonal timing of the SG flower-visiting insects, and iii) identify factors influencing the diversity of bees, syrphids, and flowering plants in the SGs. To reach these aims, we conducted bi-monthly timed pollinator surveys in two Maryland reserves during the 2019 growing season. Our results indicate that syrphids and bees were the primary visitors to flowers in the SGs. Additionally, a rare, newly described species of syrphid (Trichopsomyia litoralis, only known from coastal areas) was collected from both areas. Adult seasonal timing of flower visitors matched their known flight seasons, although some species were observed only during the end of their flying season. Habitat area and perimeter:area ratios were found to be poor predictors of bee, syrphid, and flower diversity measures, while plant diversity and richness were significantly positively correlated with bee and syrphid measures. Our study is the first to investigate the East-Coast Serpentine Grassland pollination ecology, building the foundations for transforming this understudied, fragmented, and rare ecosystem into a new model system in landscape ecology and evolution.
