Survival during the 4.2 ka event by Jomon hunter–gatherers with management and use of plant resources at the Denotame site in central Japan

The impact of the 4.2 ka event on the subsistence of Jomon hunter–gatherers was studied at the Denotame site in central Japan with pollen, plant macrofossils, and wood remains. From 6,250 cal bp, the middle phase of the early Jomon period, to 3,750 cal bp, the late Jomon period, there were deciduous forests dominated by Quercus on the higher land between the river valleys. In the lower land in the valleys or at their edges Alnus japonica grew at 6,250–5,900 cal bp, Juglans mandshurica at 6,100–3,750 cal bp, and Aesculus turbinata at 4,500–3,750 cal bp. While maintaining their settlements and making pottery from 5,300 to 3,600 cal bp, Jomon people managed Castanea crenata and Toxicodendron vernicifluum and used their timber and other resources and the nuts of Juglans through these periods and of Aesculus in later periods. Abundant occurrences of other plants from archaeological remains indicated the use of plants with edible fruits such as Morus, Quercus, Phellodendron amurense, Actinidia, Vitis, Rubus, and Broussonetia, and those with other uses such as Styrax, Sapindus mukorossi, and Sambucus racemosa. In contrast to many instances of social disturbance through the 4.2 ka event on the Asian continent, the event did not affect the life of the Jomon hunter–gatherers at Denotame. The stable temperature of the warm Kuroshio current during this period probably supported an unchanged environment and the undisturbed life of the Jomon people in central Japan.