Pollination is an ecosystem function of global importance. Yet, who visits the flower of specific plants, how the composition of these visitors varies in space and time and how such variation translates into pollination services are hard to establish. The use of DNA barcodes allows us to address ecological patterns involving thousands of taxa that are difficult to identify. To clarify the regional variation in the visitor community of a widespread flower resource, we compared the composition of the arthropod community visiting species in the genus Dryas (mountain avens, family Rosaceae), throughout Arctic and high-alpine areas. At each of 15 sites, we sampled Dryas visitors with 100 sticky flower mimics and identified specimens to Barcode Index Numbers (BINs) using a partial sequence of the mitochondrial COI gene. As a measure of ecosystem functioning, we quantified variation in the seed set of Dryas. To test for an association between phylogenetic and functional diversity, we characterized the structure of local visitor communities with both taxonomic and phylogenetic descriptors. In total, we detected 1,360 different BINs, dominated by Diptera and Hymenoptera. The richness of visitors at each site appeared to be driven by local temperature and precipitation. Phylogeographic structure seemed reflective of geological history and mirrored trans-Arctic patterns detected in plants. Seed set success varied widely among sites, with little variation attributable to pollinator species richness. This pattern suggests idiosyncratic associations, with function dominated by few and potentially different taxa at each site. Taken together, our findings illustrate the role of post-glacial history in the assembly of flower-visitor communities in the Arctic and offer insights for understanding how diversity translates into ecosystem functioning.
Bibliographical noteFunding Information:
We thank Bess Hardwick, Isabella Palorinne and Juha‐Matti Pitkänen for help with constructing the figures; Jenni Santaharju and Tobias Malm for their advice in the Bayesian phylogenetic analysis; and Eliot Miller for his advice in the phylogenetic commu‐ nity analyses. We wish to acknowledge CSC—IT Center for Science, Finland, for computational resources. Funding by the Academy of Finland (grant no. 276909 to M.T., T.H. and T.R.), by the Ella & Georg Ehrnrooth Foundation (to M.T. and T.R.), by the International Network for Terrestrial Research and Monitoring in the Arctic under the European Community’s Seventh Framework Programme (to M.T. and T.R.) and by Societas Entomologica Helsingforsiensis (to M.T.) is gratefully acknowledged. The UtqiaD vik site leaders would like to thank Mike Allen who conducted the field collections; Umiaq, LLC, for logistical support; UkpeaD vik ID?upiat Corporation and the North Slope Borough for access to their lands; and the U.S. Fish and Wildlife Service for financial support. Thanks to Jennie Rausch from Canadian Wildlife Service, Environment and Climate Change Canada for her participation in organizing the sampling at MacKenzie Delta. Thanks also to Lance Goodwin for his help in sampling at Kluane Lake.
- DNA barcoding
- arctic ecology
- ecosystem functioning
- flower visitor