title: Proxy comparison in ancient peat sediments: pollen, macrofossil and plant DNA.
abstract: We compared DNA, pollen and macrofossil data obtained from Weichselian interstadial (age more than 40 kyr) and Holocene (maximum age 8400 cal yr BP) peat sediments from northern Europe and used them to reconstruct contemporary floristic compositions at two sites. The majority of the samples provided plant DNA sequences of good quality with success amplification rates depending on age. DNA and sequencing analysis provided five plant taxa from the older site and nine taxa from the younger site, corresponding to 7% and 15% of the total number of taxa identified by the three proxies together. At both sites, pollen analysis detected the largest (54) and DNA the lowest (10) number of taxa, but five of the DNA taxa were not detected by pollen and macrofossils. The finding of a larger overlap between DNA and pollen than between DNA and macrofossils proxies seems to go against our previous suggestion based on lacustrine sediments that DNA originates principally from plant tissues and less from pollen. At both sites, we also detected Quercus spp. DNA, but few pollen grains were found in the record, and these are normally interpreted as long-distance dispersal. We confirm that in palaeoecological investigations, sedimentary DNA analysis is less comprehensive than classical morphological analysis, but is a complementary and important tool to obtain a more complete picture of past flora.
authors.affiliation: Department of Ecology and Genetics, Evolutionary Biology Centre, Uppsala University, Norbyvägen 18D, 75236 Uppsala, Sweden Centre for GeoGenetics, Natural History Museum of Denmark, University of Copenhagen, ØsterVoldgade 5-7, 1350 Copenhagen, Denmark laura.parducci@ebc.uu.se.
authors.forename: Laura
authors.identifier: http://orcid.org/0000-0003-1956-4757
authors.initials: L
authors.lastname: Parducci
authors.affiliation: Department of Environmental Sciences, University of Helsinki, PO Box 65, 00014 Helsinki, Finland.
authors.forename: Minna
authors.initials: M
authors.lastname: Väliranta
authors.affiliation: Department of Geosciences and Geography, University of Helsinki, PO Box 64, 00014 Helsinki, Finland.
authors.forename: J Sakari
authors.initials: JS
authors.lastname: Salonen
authors.affiliation: Department of Environmental Sciences, University of Helsinki, PO Box 65, 00014 Helsinki, Finland.
authors.forename: Tiina
authors.initials: T
authors.lastname: Ronkainen
authors.affiliation: Molecular Biology Centre, Interdisciplinary Research Institute on Bio-Nano-Sciences, Babes-Bolyai-University ClujNapoca, 42 TreboniuLaurian Street, 400271 Cluj-Napoca, Romania.
authors.forename: Irina
authors.initials: I
authors.lastname: Matetovici
authors.affiliation: School of Geography, Archaeology and Palaeoecology, Queen's University Belfast, Belfast BT7 1NN, UK.
authors.forename: Sonia L
authors.initials: SL
authors.lastname: Fontana
authors.affiliation: Department of Geosciences, University of Oulu, PO Box 3000, 90014 Oulu, Finland.
authors.forename: Tiina
authors.initials: T
authors.lastname: Eskola
authors.affiliation: Geological Survey of Finland, PO Box 77, 96101 Rovaniemi, Finland.
authors.forename: Pertti
authors.initials: P
authors.lastname: Sarala
authors.affiliation: Graduate School of Agricultural Science, Tohoku University, 232-3 Yomogida, Naruko-onsen, Osaki, Miyagi 989-6711, Japan.
authors.forename: Yoshihisa
authors.initials: Y
authors.lastname: Suyama
mesh_terms: D001483:Base Sequence; D018744:DNA, Plant / Q000145:classification / Q000235:genetics* / Q000266:history; D005387:Finland; D005580:Fossils; D019015:Geologic Sediments / Q000737:chemistry*; D049690:History, Ancient; D008969:Molecular Sequence Data; D060885:Multiplex Polymerase Chain Reaction; D011058:Pollen / Q000235:genetics*; D012426:Russia; D017422:Sequence Analysis, DNA / Q000379:methods; D012987:Soil / Q000737:chemistry*
chemical_list: D018744:DNA, Plant; D012987:Soil
keywords: Holocene; Weichselian interstadial; ancient DNA; barcoding; plant macrofossils; pollen