Pollen analysis, radiocarbon dating and facies analysis were performed as to a sedimentary drill core obtained from Ohnuma Mire (380m a. s. l.), located in Miyagi Prefecture, Japan. The results of radiocarbon dating and Towada-a tephra (To-a, AD915) in peat deposits show that the age of the lowest part of peat deposits in the mire goes back to approximately 1, 500yrs BP. From the result of pollen analysis, four local pollen zones were established, namely, HO-1, HO-2, HO-3, and HO-4 in ascending order. The local vegetation changes around the mire are reconstructed from those local pollen zones as follows, HO-1 zone: deciduous boreal-leaved forest composed mainly of Fagus, HO-2 zone: deciduous boreal-leaves forest dominated Quercus, HO-3 zone: coniferous forest including Pinus and Cryptomeria, and HO-4 zone: Cryptomeria.
It is inferred, therefore, that the vegetation of hilly land around the mire was Quercus crenata-Q. mongolica var. grosseserrata secondly forest from ca. 360yrs BP to ca. 150yrs BP, Pinus densiflora secondly forest and Crytomeria japonica plantation from ca. 150yrs BP to 1940s, and C. japonica plantation from 1940s to present. These vegetation changes indicate the destruction of natural vegetation by the past human activities around the mire.

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In order to make clear the effect of valley topography on the ground level wind direction under the influence of upper winds an attempt was made to study their relationship quantitatively in the mountainous regions in Chubu District, Japan.
Their relationships are different in accordance with the upper wind directions and the ground level wind directions. Daily mean wind velocity, frequency of the most frequent wind direction in the case stronger than 2m/sec in daytime and at night, and the wind direction frequency including ±45° of the direction have close relationships to the valley topography index expressed quantitatively by the form of cross-sections of the valleys. Exception is the winds at the points, which are affected by thermally formed local winds, such as land and sea breezes and mountain and valley winds.

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