Satoshi Osawa

The Forming Process of Cherry Trees Plantation Landscape in Matsuzaki Town, Izu Peninsula

The leaves of Oshima cherry (Prunus Wilson var. speciosa Makino) are edible and used to wrap sakuramochi. Seventy percent of leaves of the Oshima cherry are produced in Matsuzaki town, Izu Peninsula. In this town, cherry trees are cultivated for harvesting their leaves. These trees are closely planted and pruned, enabling them to grow many tillers, which spread out and form the distinctive landscape in this area. In this study, we investigated the actual distribution, forming process of leaves in cherry tree fields, and change in the production process in Matsuzaki town. From the results, we assumed that the number of cherry trees planted corresponded to the amount of charcoal produced. However, the field cultivation method of cherry trees was devised only by the end of the 1960s, after the production of charcoal decreased due to an energy revolution, which resulted in a crisis in the cherry tree leaf production. It was considered that cherry tree fields were distributed throughout Matsuzaki town. However, our results show that these fields are unevenly distributed.

The Faunistic Composition of Frogs Corresponding to the Rice Fields with Various Conditions in Noubi Plains

We elected an area where uniform paddy cultivation is done by the overall community, and divided roughly into five rice field types; I(Rice field and lotus field mixture area), II(Pond adjoining area), III(Rotation of crops area of rice, wheat and soybean), IV(Fabricated field / Mixture of the waterway of the ground and concrete) and V(Not-fabricated field / Mixture of the waterway of the ground and concrete) in Noubi plains. We conducted a line census investigation on a ridge in order to investigate the species composition of frogs according to the rice field type. The results of our survey, there were large numbers of frogs in the areas which have a moist cultivating environment (TypeI, V). In contrast, in the well-drained rice fields (TypeII, III and IV) where rice seedlings were transplanted in June, there were small numbers of frogs irrespective of the environmental structure. The number of frogs in Type I where different crops (rice and lotus) were cultivated in parallel was larger than that in Type V because the waterside has always existed there.