We present pollen assemblages of the early Last Glacial Biraotri Formation at the right bank of the Rakko River, Hiroo, in eastern Hokkaido. Nineteen tephra layers were recognized in the study section, and two of them are correlated to the widespread tephra Aso-4 and K-M, which have been dated to the early Last Glacial period. Eight local fossil pollen assemblage zones HRO-I to VIII are established based on the changes in the major arboreal pollen. The patterns of pollen assemblage change below and above the K-M pumice are similar and corresponding to two sedimentary cycles from gravel to peat. In each sequence, the characteristic pollen types change from Alnus, through Larix, Picea, to Larix from lower to upper. This pattern reflects succession linked to the bog development and increasingly cold climate. The pollen assemblage in the upper sequence indicates climatic fluctuation with a larger amplitude. The lower sequence suggests the smaller climatic fluctuation in oxygen isotope stage 5, and the upper one does larger change from the stage 5 to 4.
Pollen analysis was applied to a buried soil underlying the natural Cryptomeria japonica forest on Yakushima Island, in southern Japan. This soil developed above the Koya pyroclastic flow, which was deposited by an eruption from the Kikai Caldera, in 6300 y. BP. Pollen assemblages from the buried soil showed three different successional stages of vegetation recovery following the eruption, which were not reported in previous studies. 1: Grassland vegetation, dominated by Gramineae and ferns, indicating early successional stages following damage by pyroclastic flow materials. The age of this vegetation was estimated to be between 5170 and 6300 y. BP. 2: Mixed grassland and forest vegetation with high species diversity, characterized by the presence of Haloragis and Myrica. 3: Forest vegetation dominated by Cryptomeria and Trochodendron, corresponding to present surrounding vegetation, but having different species composition.
Plant macrofossil and fossil pollen assemblages in a well buried in the 9th century at the KazusaKokubuniji Site, one of the national temples in Kodai Period, were described and palaeovegetation around the temple was reconstructed. Plant macrofossil assemblages included many cultivated plants such as Pru.nus mume, P. persica, Diospyrus, Solanum melongena and Lagenaria siceraria. The palaeovegetation in and around the temple was mainly composed of woody plants such as Cephalotaxas harringtonia, Gettis sinensis var. japonica and Zelkova serrata, and many herbaceous plants that are common in and around human habitation. Those are new data on the relationship between human and plants at the national temple in Kodai Period in the southern Kanta.
The Last Glacial and Postglacial vegetation were reconstructed from a palynological study on the pond and peat bog sediments intercalating a widespread tephra known as the Aira-Tn ash(AT), at Fusedame pond located in the south-eastern part of Ohmi Basin. Around a time of AT falling in the Last Glacial period, mixed forests of conifers, such as Pinus subgen. Haploxylon, Picea, Abies and Tsuga, and broad-leaved deciduous trees, such as Quercus subgen. Lepidobalanus and Betula,were existed in the area surrounding peat bog and wet land thickly covered with A/nus and Myrica. During Kodai and Chusei Periods, Fusedame pond was created at moor, where Myriophyllum, Brasenia and Nymphoides indica grew. Around the pond, the vegetation changed from evergreen broad-leaved forest to pine forest, influenced by human activities.