Abstract
At Ooyazawa in the southern Aomori Plain, vegetation history from the Early Jomon Period to the Ancient Period was reconstructed from fossil pollen assemblages. A small valley containing buried forests and Early Jomon artifacts was discovered at the study site. This valley was mostly filled with peat to silty peat sediments intercalated by Towada Chuseri Tephra (To-Cu) and several layers of fluvial deposits. The organic contents of the valley sediments were positively correlated with the quantity of Alnus and Fraxinus pollen and monolete spores. This showed that marsh forests of Alnus and Fraxinus in the valley were frequently buried by inorganic sediments brought by floods. Five local pollen assemblage zones were recognized from the composition of arboreal pollen excluding Alnus and Fraxinus: period a of deciduous forests of Fagus and Quercus (Lepidobalanus), period b of deciduous forests of Fagus and Quercus (Lepidobalanus), an expansion period of Castanea and Rhus, a period of deciduous forests of Quercus (Lepidobalanus) and Aesculus, and a period of deciduous forests of Fagus and Quercus (Lepidobalanus). Vegetation history at Ooyazawa corresponded closely with that at and round the San-nai Maruyama Site, and Jomon people at Ooyazawa used forest resources similarly as at that site.
