New evidence of late Neolithic and early Metal Period agriculture in Turku, southwest Finland

Vegetation History and Archaeobotany https://doi.org/10.1007/s00334-024-01008-5 ORIGINAL ARTICLE New evidence of late Neolithic and early Metal Period agriculture in Turku, southwest Finland Mia Lempiäinen-Avci1 · Jouko Pukkila2 · Auli Bläuer3 · Mirva Pääkkönen3 · Henrik Asplund3 Received: 3 October 2023 / Accepted: 17 June 2024 © The Author(s) 2024 Abstract A re-evaluation of late Neolithic cereal grains, combined with new archaeobotanical data, add to the evidence of late Neolithic and early Metal Period farming in southwest Finland. Earlier indications of late Neolithic cereals at the Niuskala Kotirinne site in Turku are confirmed by new radiocarbon dating results. An early occurrence of Hordeum has also found at a second site nearby, Räntämäki Riihivainio. The finds are discussed in relation to early dates of cereal finds and other indications of farming, as well as general interpretations of the earliest cereal growing in Finland and the northern Baltic region. Keywords Archaeobotany · Archaeology · Barley · Cereal growing · Early Metal Period · Finland · Late Neolithic Introduction Early farming in Finland The burning question of the date when the first signs of farming occur in different areas of northern Europe has been explored by researchers from a range of disciplines such as palynology, archaeobotany, archaeozoology and archaeology (Zvelebil and Dolukhanov 1991; Bonsall et al. 2002). It has been shown that the effects of human activities on soils are evident from the start of farming 6,000 years ago in Fennoscandia; the earliest cereals were planted on pristine soils and agriculture intensified by the late Neolithic (Alenius et al. 2021; Gron et al. 2021). Early agriculture in Finland has recently been studied from many perspectives and the data emphasize the importance of multidisciplinary studies for this. For example, animal Communicated by K.-E. Behre. Mia Lempiäinen-Avci 1 Biodiversity Unit, University of Turku, Herbarium FI-20014, Finland 2 Arkebuusi Cooperative, Turku, Finland 3 Department of Archaeology, University of Turku, Turku FI-20014, Finland and plant material, including seeds, pollen and starch, as well as analyses of organic residues on pottery have added greatly to our knowledge (Alenius et al. 2013, 2017; Bläuer and Kantanen 2013; Cramp et al. 2014; Juhola et al. 2014; Lahtinen et al. 2017; Ahola et al. 2018; Vanhanen 2019; Vanhanen et al. 2019; Pääkkönen et al. 2020). Despite all the information gathered, our knowledge is still somewhat fragmented. In southwest Finland, the earliest evidence of agriculture seems to relate to the Kiukainen culture (Fig. 1), which dates back to 2500/2300–1800/1500 bc (all bc dates are calibrated) (Haggrén et al. 2015) and is often referred as the late (or final) Neolithic. Previous studies have found evidence of cereal grains and Hordeum-type pollen, bones of sheep or goats and residues of milk lipids in pottery residues, all dated to this culture (Vuorela and Lempiäinen 1988; Bläuer and Kantanen 2013; Pääkkönen et al. 2020). Although there is only scattered evidence of the way of life at this period, the overall pattern seems to indicate that it was mainly hunting, fishing and gathering together with some farming until the Metal Period (Bläuer and Kantanen 2013; Lahtinen and Rowley-Conwy 2013; Vanhanen and Koivisto 2015; Pääkkönen et al. 2020; Heyd 2022). The Metal Period includes the Bronze Age and the pre-Roman Iron Age ca. 1700–1 bc. Additionally, the majority of the bone material as well as the data from lipid analyses indicate dependence upon marine resources, 13 Vegetation History and Archaeobotany Fig. 1 Location of the study area around Turku in southwest Finland. The hatched area shows the distribution of the Kiukainen culture sites. Map by Henrik Asplund fishing and sealing (Asplund et al. 1989; Bläuer and Kantanen 2013; Pääkkönen et al. 2020). These suggest that agriculture in southwest Finland was small-scale and supplemented by other resources. It was scattered over a small geographical area and the surviving botanical material is scarce. This study aims to further understanding of the early farming in Finland; we publish new botanical and radiocarbon results here from two settlements dating to the Kiukainen culture in the late Neolithic, Niuskala at Kotirinne (60°28’42” N; 22°19’26” E) and Riihivainio at Räntämäki (60°28’35” N; 22°18’44” E), both located in Turku, southwest Finland. The discussion also includes an evaluation of bone material from the sites as well as results of lipid analysis of pottery from the Niuskala Kotirinne site. Finally, we discuss late Neolithic and early Metal Period farming in southwest Finland, in general. 13 Late Neolithic sites Niuskala Kotirinne In investigations into early agriculture in Finland or more generally the northeastern shores of the Baltic Sea, one specific site, Niuskala Kotirinne in Turku, is important. It dates to the late Neolithic or early Bronze Age, within the Kiukainen culture (2500/2300–1800/1500 bc) according to the chronology of southwest Finland (Pihlman and SeppäHeikka 1985). At this time, Niuskala Kotirinne was on an island in an inland archipelago. Its location is typical of Neolithic sites in Finland, facing the sea on a southern slope by a sandy shore, with the open water in front of it. It is presently ca. 20–25 m above sea level (Fig. 2). The site has been subject of several excavations and surveys from 1915 until recently (Tallgren 1915; Lehtosalo Vegetation History and Archaeobotany Fig. 2 Locations of Niuskala Kotirinne and Räntämäki Riihivainio as well as nearby Neolithic sites indicated in a modelled Late Neolithic landscape. The shoreline is shown at 22 m above present sea level. Map by Henrik Asplund, based on Elevation model 2 m and Hillshade 2 m of the National Land Survey of Finland 1961; Seppänen 1977; Pihlman 1983, 1984, 1985; Korkeakoski-Väisänen 1986, 1988, 1989, 1990, 1991). The most recent survey was done in 2012 (Pukkila 2012a). Within the main area of the site there are distinctively coloured partly sooty cultural layers containing an abundance of pottery fragments and stone material, mostly porphyrite and quartz, but also some flint. Except for a few postholes and hearths, no obvious structures like building remains have been found. The previous research on the Niuskala Kotirinne material includes published plant macrofossil data (Pihlman and Seppä-Heikka 1985) and a pollen study combined with radiocarbon dates (Vuorela and Lempiäinen 1988; Jungner and Sonninen 1996), as well as soil chemical analyses (Asplund et al. 1989). A discussion on settlement development and farming techniques with reference to the Niuskala Kotirinne material has also been published (KorkeakoskiVäisänen 2012). Additionally, osteological analyses by Bläuer and Kantanen (2013) include burnt bones identified as Phocidae (unspecified seals), Esox lucius (pike), Canidae (dog or wolf) and humans. The most recent stud (...truncated)