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