VERTICAL ZONATION OF AGRICULTURAL LAND USE ON THE LOWER SOUTHERN SLOPES OF MT. ASAMA

The topic of vertical change of. agricultural activity on mountain slopes has been studied by many researchers; in particular, the studies of Waibel (1927), Peattie (1931), Troll (1968), Kawakita (1956a, b), Brush (1977) and Guillet (1983) stand out. These works have revealed that the agricultural region along mountain slopes is composed of several distinct zones laid along a vertical axis. This concept, “vertical zonation of farming belts” leads to “al-pwirtschaft, ” “verticality, ” and “mountain-production strategy” theories of mountain-sub-sistence types, and has been one of the most productive viewpoints for analyzing the characteristics of agricultural regions on mountain slopes.<br> In this paper, attempts are made to clarify the array of agricultural production zones along the lower-southern slopes of Mt. Asama by examining the change of agricultural land-use patterns with increase in altitude. The study area, situated in the middle-eastern part of Nagano prefecture, is typical of volcanic slopes in Japan (Fig. 1).<br> In order to clarify agricultural land use, the following investigations were made. First, two land use maps were made of adjoining slopes, i, e., the Shigeno and Netsu slopes (Fig. 2), and the distribution of each crop was analyzed comparatively by mesh analysis (Fig. 7_??_12-A). The mesh data were calculated by dividing the altitude zones into 14 basic units, established at 50-meter intervals. Then, the cultivation limit and the relationships between distribution of each crop and altitude were examined considering the influence of such natural environmental elements as topography and climate (Fig. 7_??_12-B). Second, attention was focused on the vertical change of a combination of the land use patterns, using a modified Weaver method. Then, altitudinal zones were combined by the group-average method of cluster analysis in order to compare the land use patterns of these two slopes (Fig. 13•14).<br> According to these analyses, three vertically-located agricultural production zones were identified, i.e., low-altitude agricultural production zone, mid-altitude agricultural production zone and high-altitude agricultural production zone, each characterized by different kinds of land use (Fig. 14). Their characteristics are as follows:<br> (1) The low-altitude agricultural production zone: This zone extends up to 750 meters in altitude, corresponding to the lowest part of the alluvial fan of a volcanic slope. Rice, fruits, and vegetables are the main agricultural crops grown in the zone. It corresponds to a warm-temperate deciduous forest zone.<br> (2) The mid-altitude agricultural production zone: This zone extends from 750 to 850 meters; it corresponds to the middle part of the alluvial fan of a volcanic slope. This is a transitional zone, situated between the low- and the high-altitude zones and showing char-acteristics of both zones. Fruits that prevail in the low-altitude zone decrease abruptly, while flowers and fodder crops, characteristic of the high-altitude zone, increase gradually with altitude. Furthermore, mulberry and industrial crops such as juice tomatoes and ginseng are representative of the crops in this zone. As a result, the mid-altitude agricultural pro-duction zone is characterized by the most varied agricultural land use on the volcanic slope. This zone corresponds to the transitional zone from a warm-temperate deciduous forest zone to a cool-temperate deciduous forest zone.<br> (3) The high altitude agricultural production zone: This zone extends from 850 to 1, 210 meters; it corresponds to the highest portions of the alluvial fan of a volcanic slope. This zone is characterized by such crops as vegetables, fodder crops, flowers and rice. It cor-responds to the cool-temperate deciduous forest zone.