Barley (Hordeum vulgare) in the Okhotsk culture (5th–10th century AD) of northern Japan and the role of cultivated plants in hunter-gatherer economies

This paper discusses archaeobotanical remains of naked barley recovered from the Okhotsk cultural layers of the Hamanaka 2 archaeological site on Rebun Island, northern Japan. Calibrated ages (68% confidence interval) of the directly dated barley remains suggest that the crop was used at the site ca. 440–890 cal yr AD. Together with the finds from the Oumu site (north-eastern Hokkaido Island), the recovered seed assemblage marks the oldest well- documented evidence for the use of barley in the Hokkaido Region. The archaeobotanical data together with the results of a detailed pollen analysis of contemporaneous sediment layers from the bottom of nearby Lake Kushu point to low-level food production, including cultivation of barley and possible management of wild plants that complemented a wide range of foods derived from hunting, fishing, and gathering. This qualifies the people of the Okhotsk culture as one element of the long-term and spatially broader Holocene hunter–gatherer cultural complex (including also Jomon, Epi-Jomon, Satsumon, and Ainu cultures) of the Japanese archipelago, which may be placed somewhere between the traditionally accepted boundaries between foraging and agriculture. To our knowledge, the archaeobotanical assemblages from the Hokkaido Okhotsk culture sites highlight the north-eastern limit of prehistoric barley dispersal. Seed morphological characteristics identify two different barley phenotypes in the Hokkaido Region. One compact type (naked barley) associated with the Okhotsk culture and a less compact type (hulled barley) associated with Early–Middle Satsumon culture sites. This supports earlier suggestions that the “Satsumon type” barley was likely propagated by the expansion of the Yayoi culture via south-western Japan, while the “Okhotsk type” spread from the continental Russian Far East region, across the Sea of Japan. After the two phenotypes were independently introduced to Hokkaido, the boundary between both barley domains possibly existed ca. 600–1000 cal yr AD across the island region. Despite a large body of studies and numerous theoretical and conceptual debates, the question of how to differentiate between hunter–gatherer and farming economies persists reflecting the wide range of dynamic subsistence strategies used by humans through the Holocene. Our current study contributes to the ongoing discussion of this important issue

Ostasien. Hirse – Wann das erste Getreide im nördlichen Ostasien domestiziert und verbreitet wurde. Die Arbeiten des Jahres 2019 (Projekte „BAYCHRON“ und „Bridging Eurasia“)

Although broomcorn and foxtail millet are among the earliest staple crop domesticates, their spread and impacts on demography remain controversial, mainly because of the use of indirect evidence. Bayesian modelling applied to a dataset of new radiocarbon dates derived from domesticated millet grains suggests that after their initial cultivation in the crescent around the Bohai Sea ca. 5800 cal yr BC (median date), the crops spread discontinuously across eastern Asia. In northern China, millet-based agriculture expanded westward only with a delay of ca. 1000 years between neighbouring regions, but supported a quasi-exponential population growth from 6000 to 2000 cal yr BC. Domesticated millet reached Kazakhstan ca. 2300 cal yr BC from where it was brought East again and introduced to Xinjiang together with wheat, barley, sheep/goat and cattle ca. 1900 cal yr BC. Even the Korean peninsula is relatively near to the area of millet’s initial domestication, its cultivation there did not start until ca. 3700 cal yr BC, i.e. after a time lag of about 2000 years. From Korea millet was taken to Japan ca. 1000 cal yr BC by peasants who kicked-off millet and rice agriculture at the easternmost isles of the Eurasian continent

Evidence of millet and millet agriculture in the Far East Region of Russia derived from archaeobotanical data and radiocarbon dating

Agriculture based on broomcorn and foxtail millet has been identified as one of the main drivers of population expansion and/or resource and innovation transfer across Neolithic and Bronze Age Eurasia. However, accurate reconstruction of spatio-temporal patterns of millet spread within and outside China remains a challenging issue. Here we use a representative set of 27 millet-based radiocarbon (14C) dates from southern Primorye to reconstruct when millet cultivation became part of hunter-fisher-gatherer subsistence in this vast southeasternmost region of Russia. The spatio-temporal distribution of the 14C data demonstrates the following picture. After the earliest conventionally accepted (although not directly dated) appearance of millet at the Krounovka-1 site in the Suifen (Razdol'naya) River catchment west of Khanka Lake around 3521–3356 BCE (95.4% probability range of calibrated ages of wood charcoal), millet agriculture is registered at the site Gvozdevo-4 located on the southern coastal plains northeast of the mouth of the Tumen (Tumannaya) River in the first half of the 3rd millennium BCE. Several archaeological sites (Novoselishche-4, Bogolyubovka-1, Rettikhovka Geologicheskaya-1, Risovoe-4) with directly dated millet indicate the spread of millet cultivation across the fertile plains around Khanka Lake during the second half of the 3rd millennium BCE. The dates obtained from the Olga-10 site on the eastern coastal plains along the Sea of Japan suggest that millet contributed to the food economy there from the beginning of the 2nd millennium BCE. The presented dataset shows the presence of millet in the north-eastern part of the study region (i.e. at the Glazovka-gorodishche site) in the second half of the 1st millennium BCE. Our dataset demonstrates that millet has been cultivated in southern Primorye since the Late Neolithic, when small-scale agriculture was introduced by Zaisanovskaya culture groups archaeologically documented in the study region and neighbouring regions of China and North Korea. This indicates that millet was an integral part of the subsistence economy of the local populations throughout the entire period under review

Location maps of the study region, Hamanaka 2, the RK12 coring site and other archaeobotanical records discussed in the text.

<p>Map compilation showing (A) the location of the study region in the northwest Pacific region; (B) the southern Primor’e Region (Russia); (C) the Hokkaido and northern Tohoku regions; (D) Rebun Island; and (E) the northern part of Rebun with Lake Kushu (white cross indicates location of the RK12 coring site) and the Hamanaka 2 archaeological site. Dots illustrate the locations of Okhotsk culture (yellow), Satsumon culture (green), Heian period (blue), and the RFE Iron Age–Eastern Xia State (red) barley records used for seed morphological comparison (see <a href="http://www.plosone.org/article/info:doi/10.1371/journal.pone.0174397#pone.0174397.s003" target="_blank">S3 Table</a> for site names and further details). Red circles in (C) show the location of the 194 Okhotsk culture sites listed in the Hokkaido archaeological site database (<a href="http://www2.wagamachi-guide.com/hokkai_bunka/" target="_blank">http://www2.wagamachi-guide.com/hokkai_bunka/</a>). The dashed line marks the proposed boundary of where the two barley morphotypes dominate. Bathymetry of Lake Kushu (0.5 m isolines) is based on survey data provided by T. Haraguchi (Osaka City University). Topographic maps are based on data from the elevation Shuttle Radar Topography Mission (SRTM) V4.1 [<a href="http://www.plosone.org/article/info:doi/10.1371/journal.pone.0174397#pone.0174397.ref024" target="_blank">24</a>]. Isolines for the terrestrial area in (E) are drawn from a topographic map [<a href="http://www.plosone.org/article/info:doi/10.1371/journal.pone.0174397#pone.0174397.ref025" target="_blank">25</a>].</p

Sample-specific total counts of selected macrobotanical remains and floated litres from the Okhotsk culture layer units of Hamanaka 2.

<p>Sample-specific total counts of selected macrobotanical remains and floated litres from the Okhotsk culture layer units of Hamanaka 2.</p

Simplified pollen diagram representing the section dating between 50 cal yr BC and 1540 cal yr AD (67 pollen spectra) of the sediment core RK12 from Lake Kushu, Rebun Island.

<p>Chronology of prehistoric cultures in northern Hokkaido comprises Epi-Jomon (EJ; ca. 100 cal yr BC–500 cal yr AD including the Susuya tradition ca. 100–500 cal yr AD), Okhotsk culture (OK; ca. 500–950 cal yr AD), and Proto-Ainu/Formative Ainu (PA; ca. 950–1600 cal yr AD) (according to [<a href="http://www.plosone.org/article/info:doi/10.1371/journal.pone.0174397#pone.0174397.ref026" target="_blank">26</a>] and [<a href="http://www.plosone.org/article/info:doi/10.1371/journal.pone.0174397#pone.0174397.ref027" target="_blank">27</a>]).</p

Radiocarbon dates and calibrated ages on carbonised barley seeds from the Okhotsk culture layers of the Hamanaka 2 site, Rebun Island, Hokkaido.

<p>Radiocarbon dates and calibrated ages on carbonised barley seeds from the Okhotsk culture layers of the Hamanaka 2 site, Rebun Island, Hokkaido.</p

Box-plots showing the L/W distribution of barley seeds from the Hamanaka 2 Okhotsk culture layers (this study) and of selected records from other regions.

<p>The boxes delineate the 25–75% quartiles (regular font) with the median (italic font) shown as an inset horizontal line. The whiskers (inner fence) are defined as the array from top/bottom of the box to the largest/smallest data point less than 1.5 times the box height from the box. Data points inside and outside (outliers) the whiskers are marked by grey and blue dots, respectively. Dotted horizontal lines indicate arithmetic means of Satsumon barley populations. Sample size (if know) and site numbers used in <a href="http://www.plosone.org/article/info:doi/10.1371/journal.pone.0174397#pone.0174397.g001" target="_blank">Fig 1</a> are provided. Ages are given in calendar years.</p

Hamanaka 2 cultural layers associated with the Okhotsk culture and available flotation samples.

<p>Hamanaka 2 cultural layers associated with the Okhotsk culture and available flotation samples.</p