Molecular Ecology Resources (2016) 16, 809–822 doi: 10.1111/1755-0998.12489 Establishing a community-wide DNA barcode library as a new tool for arctic research H. WIRTA,1 G. VARKONYI,2 C. RASMUSSEN,3 R. KAARTINEN,4 N. M. SCHMIDT,5 P. D. N. HEBERT,6 M. BARTAK,7 G. BLAGOEV,6 H. DISNEY,8 S. ERTL,9 P. GJELSTRUP,10 D. J. GWIAZDOWICZ,11 12 13 14 15 € € 12 € € 1 L. HULDEN, J. ILMONEN, J. JAKOVLEV, M. JASCHHOF, J. KAHANPAA, T. KANKAANPAA, P. H. KROGH,10 R. LABBEE,6 C. LETTNER,9 V. MICHELSEN,16 S. A. NIELSEN,17 € T. R. NIELSEN,18 L. PAASIVIRTA,19 S. PEDERSEN,6 J. POHJOISMAKI,20 J. SALMELA,21 € P. VILKAMAA,12 H. VARE,22 M. VON TSCHIRNHAUS23 and T. ROSLIN 1,4 1Department of Agricultural Sciences, University of Helsinki, Latokartanonkaari 5, 00790 Helsinki, Finland, 2Finnish Environment Institute, Natural Environment Centre, Friendship Park Research Centre, Lentiirantie 342B, 88900 Kuhmo, Finland, 3Department of Bioscience, Aarhus University, Ny Munkegade 114, DK–8000 Aarhus, Denmark, 4Department of Ecology, Swedish University of Agricultural Sciences, Box 7044, 750 07 Uppsala, Sweden, 5Arctic Research Centre, Department of Bioscience, Aarhus University, Frederiksborgvej 399, DK-4000 Roskilde, Denmark, 6Biodiversity Institute of Ontario, University of Guelph, Guelph, ON N1G 2W1, Canada, 7Department of Zoology and Fisheries, Faculty of Agrobiology, Food and Natural Resources, Czech University of Life Sciences, 165 21 Praha 6 - Suchdol, Czech Republic, 8Department of Zoology, University of Cambridge, Cambridge CB2 3EJ, UK, 9Division of Conservation Biology, Vegetation Ecology and Landscape Ecology, Department of Botany and Biodiversity Research, University of Vienna, Rennweg 14, 1030 Vienna, Austria, 10Department of Bioscience, Aarhus University, Vejlsøvej 25, Silkeborg DK-8600, Denmark, 11Department of Forest Pathology, University of Life Sciences, Wojska Polskiego 71c, Poznan 60625, Poland, 12Finnish Museum of Natural History, Zoology Unit, University of Helsinki, Pohjoinen Rautatiekatu 13, 00100 Helsinki, Finland, 13Mets€ahallitus, Parks & Wildlife Finland, PO Box 94, 01301 Vantaa, Finland, 14Finnish Environment Institute, Mechelininkatu € 34A, 00250 Helsinki, Finland, 15Station Linne, Olands Skogsby 161, 38693 F€arjestaden, Sweden, 16Zoological Museum of the University of Copenhagen, Universitetsparken 15, DK-2100 Copenhagen, Denmark, 17Department of Environmental, Social and Spatial Change, Roskilde University, Universitetsvej 1, PO Box 260, DK-4000 Roskilde, Denmark, 18Sandvedhagen 8, NO-4318, Sandnes, Norway, 19Ruuhikoskenkatu 17 B 5, 24240 Salo, Finland, 20Department of Biology, University of Eastern Finland, P.O. Box 11, 80101 Joensuu, Finland, 21Mets€ahallitus, Ounasjoentie 6, 96101 Rovaniemi, Finland, 22Finnish Museum of Natural History, Botany Unit, University of Helsinki, Unioninkatu 44, 00140 Helsinki, Finland, 23Fakulta¨t Biologie, Universita¨t Bielefeld, Universita¨tsstrasse 25, 33615 Bielefeld, Germany Abstract DNA sequences offer powerful tools for describing the members and interactions of natural communities. In this study, we establish the to-date most comprehensive library of DNA barcodes for a terrestrial site, including all known macroscopic animals and vascular plants of an intensively studied area of the High Arctic, the Zackenberg Valley in Northeast Greenland. To demonstrate its utility, we apply the library to identify nearly 20 000 arthropod individuals from two Malaise traps, each operated for two summers. Drawing on this material, we estimate the cover- age of previous morphology-based species inventories, derive a snapshot of faunal turnover in space and time and describe the abundance and phenology of species in the rapidly changing arctic environment. Overall, 403 terrestrial animal and 160 vascular plant species were recorded by morphology-based techniques. DNA barcodes (CO1) offered high resolution in discriminating among the local animal taxa, with 92% of morphologically distinguishable taxa assigned to unique Barcode Index Numbers (BINs) and 93% to monophyletic clusters. For vascular plants, resolution was lower, with 54% of species forming monophyletic clusters based on barcode regions rbcLa and ITS2. Malaise catches revealed 122 BINs not detected by previous sampling and DNA barcoding. The insect community was domi- nated by a few highly abundant taxa. Even closely related taxa differed in phenology, emphasizing the need for spe- cies-level resolution when describing ongoing shifts in arctic communities and ecosystems. The DNA barcode Correspondence: Helena Wirta, Fax: +358-9-191-58582; E-mail: helena.wirta@helsinki.fi © 2015 John Wiley & Sons Ltd 810 H. WIRTA ET AL. library now established for Zackenberg offers new scope for such explorations, and for the detailed dissection of interspecific interactions throughout the community. Keywords: arthropod, DNA barcode library, Greenland, high arctic, species diversity Received 24 June 2015; revision received 9 November 2015; accepted 17 November 2015 than previously thought (Hodkinson & Coulson 2004; Introduction Wirta et al. 2015b), but community-level descriptions of DNA sequences offer powerful tools for identifying the food webs including terrestrial arthropods are only members of natural communities (e.g. Kaartinen et al. beginning to emerge from the Arctic (Wirta et al. 2014, 2010) and for describing the interactions between them 2015b). Such descriptions rely on techniques for the iden- (Clare 2014; Wirta et al. 2014). Current techniques offer tification of species remains in gut contents and faecal scope for massive enumeration of taxa occurring at a material, as best resolved by molecular techniques (Clare given site at a given time (Hajibabaei et al. 2006) – but to 2014; Wirta et al. 2014). Overall, confronting each of these collate such information with taxa of known identity, challenges will call for a comprehensive resource allow- ecology and lifestyle, we need reference libraries of DNA ing the species-level resolution of all types of biological barcodes. While DNA barcode libraries are being stocked samples across arctic communities. at an impressive pace, they are often targeted at or To define the composition, phenology and interac- biased towards particular taxa. To offer scope for versa- tions in species of an arctic area, we here report the estab- tile assessment of full communities and food webs, the lishment of a barcode library for species from an establishment of comprehensive reference libraries cov- intensively studied site, the Zackenberg Valley in North- ering major parts of the flora and fauna remains a prior- east Greenland (Meltofte & Rasch 2008). To our knowl- ity for current research. edge, this is one of the first comprehensive DNA barcode Arctic ecosystems are particularly amenable to the libraries established for a terrestrial site, encompassing establishment of comprehensive DNA barcode libraries. more than 80% of the local diversity of animal and vascu- Here, species diversity is relatively low, and vegetation lar plant taxa as previously detected by morphological structure simple and accessible to sampling. Thus, where characters. Drawing on this novel resource, we test the the comprehensive assessment of the fauna of a single ability of DNA barcodes of standard regions (CO1 for tropical site may call for more than 65 person-years of animals, rbcLa and ITS2 for plants) to distinguish among work (Basset et al. 2012), the same can more easily be species within the local community. To demonstrate the achieved in a high-arctic context. utility of this tool, we apply it to community-level arthro- Knowing both the species and their ecology in the pod samples collected by Malaise traps. More specifi- Arctic is central for current research and part of arctic cally, the comprehensive DNA barcode library allows us monitoring efforts (CAFF Terrestrial Steering Group to answer a series of questions: How well do DNA bar- 2014). While the Arctic region is currently experiencing codes discriminate among morphologically defined taxa rapid climate warming (ACIA 2005), we still know rela- within the target community? What community proper- tively little about its animal and plant communities – ties are resolved by the Malaise trap material? How apart from the fact that they are changing (Settele et al. many new taxa are detected when identifying close to 2014). At least three components of Arctic transition call 20 000 individuals? What does the resulting individual- for accurate descriptions of communities. First, species’ level resolution reveal in terms of community structure? ranges are shifting, and this will likely increase the spe- Which taxa dominate the community, and when? cies richness of the Arctic. However, evaluating this Beyond the current objectives, the DNA barcode library hypothesis is challenging, as changes in species composi- has already allowed us to resolve trophic interactions tion are poorly documented at arctic sites (Killengreen within this high-arctic food web, with insights reported et al. 2007; Post et al. 2009; Wardle et al. 2011; Gilg et al. elsewhere (Wirta et al. 2014, 2015a,b). 2012). Second, drastic phenological changes are currently being observed in the Arctic (Høye et al. 2007, 2013). Materials and methods Nonetheless, current descriptions of such changes mostly rely on observations from higher taxa, with limited Study area understanding of species- and population-level change 0 0 (Høye et al. 2007; Miller-Rushing et al. 2010; Høye et al. Our study area, the Zackenberg Valley (74°28 N/20°34 W)