The distribution and ages of abandoned charcoal producing kilns were investigated in the hills around the Onuma Wetlands in the northwestern part of Miyagi Prefecture for the purpose of clarifying the relationship between landscape development and human use of forest resources as fuel in hilly areas. First, morphological standards for identifying abandoned charcoal producing kilns were established based on their description in previous studies and the results of an interview with a former charcoal production worker. A field survey based on the morphological standards revealed the existence of a lot of kilns in the hills around the Onuma Wetlands. It is certain, therefore, that charcoal production was active in these hills. Most of the kilns were located on concave breaks of slopes. All of the kiln entrances were facing downhill. These characteristics indicate that the micro-landform of hillslopes was considered in order that charcoal production might progress conveniently. The bottoms of abandoned kilns were filled with sand, silt, and clay including abundant charcoal fragments, which were the remnant of produced charcoal. Radiocarbon dating of these charcoal fragments suggested that most of the kilns were used after seventeenth century. This period might correspond with the time of dominance of the Quercus serrata and Quercus crispula secondary forest in the pollen diagram obtained in the same area. It can be inferred that the dominance of the Quercus secondary forest was affected by the destruction of the natural forest by man for charcoal production.

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The vegetation of the Osado Mountains ridge at 800 to 1, 000m asl is characterized by patches of bare land and grassland. These patches are located on a ridge that extends from northeast to southwest. At this site, the winter monsoon winds from the northwest erode granules and silt from the Earth's surface, thereby making it difficult for plants to take root and grow. The wind also removes snow. Most surviving plants eventually die because of the cold and dry weather. The weather and geomorphological conditions of the grassland are very severe, and only alpine plants can grow in these sites. The alpine plants are growing now because such an environment kept by winter monsoon constantly.

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The authors observed the blowing wind-holes at four locations (1-4) in the Kanto Mountains. The remains of the warehouses surrounded by the stone walls were left at the site of these wind-holes, and they were being used as natural refrigerators for the the silkworm eggs since the early stages of the 20th century. In such wind holes cool air is blowing from the openings in the surface deposits of landslides, talus slopes and block slopes in summer. As for the temperature in three wind holes (2-4), they rose about the freezing point in April or May. In one other wind hole (1; Arafune-fuketsu), it was below the freezing point and ground-ice remained in June.

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