Based on changes in facies, the Pleistocene Yamanobe Formation in the Nara Basin is divided into three members, the Upper Silt, Middle Peat and Lower Sand Members. Six pollen diagrams of the Last Glacial deposits, around the 20, 000 years ago, from the Yamanobe Formation together with the Nanmatsu Formation, which developed in the eastern part of the Nara Basin, are presented. Pollen from the Lower Sand Member, about 30, 000 years ago, showed that an open habitat was extensive in the basin, and that deciduous broad-leaved trees accompanied by Cryptomeria existed in the areas surrounding the basin, suggesting a temperate climate. Pollen from the Middle Peat Member, in which the Aira-Tn ash is intercalated, provides good evidence for an open habitat similar to the preceding stage in the basin. Pinus subgen. Haploxylon as well as Tsuga, Quercus subgen. Lepidobalanus, and Betula in the surrounding area of the basin indicate a cool temperate climate. The fall of the Aira-Tn ash affected vegetation, but no specific changes could be detected. The vegetation changes recorded are thought mainly to be of the local environments at respective sites. As for the Upper Member, there is evidence for open and sparse vegetation in the basin that followed the preceding members, although Tsuga pollen is well represented after the Sakate ash fall which occurred about 10, 000 years ago.

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Along Shichitaro-Ridge on the northwestern slope of Mount Fuji, a larch scrub community is scattered in patches, forming an island, where the tree line is 2, 700 meters in altitude. This paper reports the results of an investigation of the tree height and diameter, tree age, and distribution of buried seeds, as a clue to the origins of the larch scrub community.
The tree height and diameter change with altitude in spite of its short stature. However, tree age, number of buried seeds, and number of seed-lings are not always dependent upon altitudinal change. These facts lead us to assume that the present island-like scrub community has been caused by unstable accumulation covering the area. The existence of a buried A-horizon above the present forest line and the fir trees mingled with the scrub suggest that a well-developed forest community was formed here, was buried in the slope deposited subsequently, and then was turned into scrub.

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The Ukishimagahara Lowland is situated along the innermost margin of Suruga Bay. A barrier-backswamp system is recognized along the present coastline. In addition, two barriers buried beneath the present backswamp are developed behind the present coastal barrier in the most part of the lowland. In this paper, these three coastal barriers are called barriers I to III, in order from landward to seaward.
Megazuka is an archaeological site located in the middle of the Ukishimagahara Lowland. It is situated on the oldest coastal barrier (barrier I). Excavated materials indicate that Megazuka was occupied by pre-historical people from the middle of the Jomon period (ca. 4, 000yrs BP) until the middle of the Kofun period (ca. 1, 500yrs BP).
The purpose of this paper is to discuss the influence of environmental changes on human activity in the Ukishimagahara Lowland.
The development of coastal barriers in the Ukishimagahara Lowland and the environmental changes around Megazuka are summarized as follows (Matsubara, 1988, 1989). A bay had been formed in the Ukishimagahara Lowland at least 9, 000yrs BP. Coastal berrier I began to develop around 8, 000yrs BP and began to enclose the bay about 7, 000yrs BP. Coastal barrier II was constructed between 5, 000 and 4, 000yrs BP, and the area around Megazuka changed into a lagoon. The completion of coastal barrier II about 4, 000yrs BP caused the lagoon to change into a backswamp. The construction of coastal barrier III was finished around 2, 000yrs BP.
A series of excavations at Megazuka were carried out from 1988 to 1989. Microlandforms and the stratigraphic sequence at Megazuka were clarified along with the periods of human activity.
The relationships between environmental changes and human activity at Megazuka are inferred as follows.
The initial stage of human activity coincided with the period when the area around Megazuka changed from a lagoon to a backswamp with the construction of the coastal barrier II (ca. 4, 000yrs BP). In addition, the initial stage of human settlement was coincident with the period when coastal barrier III was completed and came to enclose the backswamp (ca. 2, 000yrs BP).
The human settlement at Megazuka was abandoned at the time of the fall of the Obuchi Scoria (ObS) from Mt. Fuji (ca. 1, 500yrs BP).
Furthermore, tectonic movement in the Ukishimagahara Lowland is characterized by subsidence (westward and landward downtilting), which buried the former coastal barriers beneath the backswamp. Continued burial of barriers made the environment around Megazuka unsuitable for human settlement.
These findings indicate that volcanic activity and tectonic movement influenced the development of human settlement in the Ukishimagahara Lowland.

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There are two opinions about the Last Glacial ice sheet of Iceland: one is that a continuous large ice sheet covered the whole island, and the other is that several thin ice sheets and a fairly wide ice-free area existed. The thickness of the Last Glacial ice sheet in the central island is estimated from the alititude of stapi (volcanic table mountains), and from the ice sheet profile corresponding to its area which is controlled by the depth of the sea surrounding the island. Glacial landforms of the coastal mountain area of the island suggest that the ice dome was thin in the marginal areas of the island. Corresponding to the distribution of the ice sheet of the Last Glaciation, the altitude of the Late Glacial highest shoreline generally rises toward the center of the mainland ice sheet. Furthermore, the altitude distribution suggests the existence of small ice domes in the northwest peninsula. The maximum height of the shoreline is about 100m.
Two glacier readvances with similar extent occurred in the Older and Younger Dryas stages. The glacier seems to have almost disappeared in the early Holocene, and then has advanced since the Neoglaciation. Although reliable fluctuation curves corresponding to this glacial change are not yet recognizable, smooth curves drawn in some areas indicate that the present coastal area was uplifted by 100 to 150m from the end of the Pleistocene to the early Holocene, while it has subsided since the mid-Holocene in the present coastal area.

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Both Late and Final Paleolithic sites were studied. A total of 8 reference sites in Primorye were investigated. The Paleolithic sites Geographical Society Cave and Osinovka belong to the warm Chernoruchie (Q_III³) period, 25, 000-35, 000 yrs BP. The Paleolithic sites Ustinovka I, Suvorovo III-IV belong to the Sartan (Q_III⁴) cold period, about 10, 000-25, 000 yrs BP. Preceramic sites Gorbatka III, Ilistaya I and Timofeevka I belong in the Late Glacial period (10, 000-12, 000 yrs BP) and Early Holocene (8, 000-10, 000 yrs BP).

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