With the concentration of population in cities in 1960's, there have been drastic but chaotic conversions of agricultural land to urban uses in the suburban areas. This trend brought about the destruction of traditional functions of paddy fields, upland feuds, and coppices, which prevented the occurrence of floods, and the area has come to suffer from a flood even with a small rain shower.In this paper, the writer studies the class differentiation of farmers in relation to conversion of land and ownership in the Kurome River Basin, Niiza City, Saitama Prefecture. This area is often inundated with water. As a result of my interview investigation of twenty farmers in the district of Horinouchi, where the Kurome River has frequently overflowed, the following tendencies were recognized: 1) The area subject to flood, has extended year by year. But farmhouses did not suffer from a flood because they were on a little higher grounds. 2) The conversion of the land use in this area caused the frequent floods but there seems to be a background that the farmers are less concerned about the water and irrigation canals they have been using, as they tend to specialize in producing only vegetables. 3) The buyers of the farmland are mainly these three: public enterprises, real estate sub-dividers, and individuals. The public works such as municipal roads and Kan-Etsu Expressway construction, and river conservation made the land price high and led to the con-version of farmland. Since 1967, the parcels of paddy fields which they had been frequently flooded, were converted into subdivisions. Since early 1960's individuals who wanted residential lots have bought many but small parcels where open field vegetables such as carrots were cultivated. 4) The farmers that obtained funds from disposing their farmlands and reinvested in agricultural sectors such as carrot production and hog raising made themselves owner farmers. But, the farmers that spent the funds on their living or rental houses construction turned to be part time farmers who cultivate vegetables for their own consumption. In this district where farmers have given up rice production and tend to specializein vegetables like carrots, as the urbanization is sprawling, the class differentiation of farmers is determined by both the type of disposal of farmlands (such as its time, scope, destination, and price) and the number of family members engaging in farming. This class differentiation is transitional and it will be surely intensified by the circumstances that are getting worse for agriculture.
The Japanese black bear (Selenarctos thibetanus japonicus) is a representative large wild mammal which has had close relations with the life of the Japanese. The animal has been an object of hunting from ancient times, because it is believed to have certain medicinal value. However, few studies have been done on the ecology of the Japanese black bear, or on its habitat distribution, both of which may be much affected by changes in man's life style. The purpose of this study is to ascertain primarily changes in the distribution of the Japanese black bear in the West Chugoku Mountains since the Taisho era (1912_??_1926). The location, which remained uninvestigated until this study, marks the western fringe of the animal's habitat in Japan. The findings are as follows: 1) From the Taisho era to early Showa (1926_??_1944), the Japanese black bear maintained its habitat in virgin broadleaf deciduous forests containing beeches (Fagus crenata Blume), horse chestnuts (Aesculus turbinata Blume), varieties of Japanese oaks (Quercus mongolica Fischer var. grosseserrata Rehd, et Wils; Quercus serrata Thunb), etc. Such forests supplied Japanese black bear's food (nuts, berries, buds, leaves, stalks, etc.) as well as provided tree hollows for hibernation. Thus, the bears seldom appeared in villages. At that time, the Japanese black bear commanded good prices mainly as material for medicine, and its hunting constituted one of the important side jobs in the winter season. 2) From around 1960, the virgin broadleaf deciduous trees have been replaced by Japanese cedar trees (Cryptomeria japonica D. Don) through afforestation. As a result, Japanese black bears, losing source of food and places for hibernation, have been driven out of their former habitat. They have thus started to hibernate in the vicinity of villages, or damaging crops and becoming a nuisance to the villagers. After World War II, hunting for Japanese black bears has declined due to the increased availability of synthetic medicine, but in contrast hunting for ellmination has increased.
There are a lot of artificial cutting slopes composed of various beds, that is, volcanic ash, clayey, sandy beds and so on, and such slopes have frequently marked relief or irregularity. It is considered that the relief indicates the difference in the properties of each bed. In Tsukuba upland, many cutting slopes have been artificially formed accompanied with the expansion of residential areas, and a few number of crack horizons are usually observed on the slope as is often the case with other places in Kanto Regions, covered with so called “Kanto Loam” (tephra) deposited in late Pleistocene. The authors analyzed physical, mechanical properties, and mineral constituents of “Kanto Loam” composing cutting slope in order to understand the crack forming mechanism and erodibility of the slope located near Tsukuba Academic city. The results obtained are as follows: (1) The relief or irregularity of the slope is greatly concerned with crack development (Fig. 2). It does not always correspond to mechanical properties estimated from soil hardness (P) and plasticity index (PI), but has close relations with ability of crack formation caused by physical, chemical properties and mineral constituent (Table 1, Photo. 2). (2) The beds 2 and 7 (Photo. 1, Fig. 2), having the ability of great shrinkage upon dry-ing, show the remarkable crack formation, while the bed 3 has the opposite chracteristics (Fig. 3). (3) The crack formation in the bed 7 is attributed to the great amount of clay content. In the “Kanto Loam”, the existence of imogolite, in addition to clay content, seems to play the important role in this phenomenon (2, 4 in Photo. 2). (4) The crack formation in the beds 2 and 7 increases the susceptibility to soil fall, and excerts the important influence upon relief formation on cutting slope composed of “Kanto Loam”.