Conservation of Satoyama Coppice Forest and Terraced Field/Orange Grove as Traditional Cultural Landscape in Northern Kyushu

摘要

Satoyama coppice forests and terraced fields historically produced firewood, charcoal and food, and thus they maintained variety of flora and fauna, and kept attractive cultural landscape. However, they are seriously losing such a scenery and bio-diversity due to the lack of management by labor shortage and the prevalence of fossil fuel. Mt.Hiyama and Himeshima Island were chosen to clarify the transition in the land-use and vegetation. The both sites are located on the shore in the northern Kyushu and faced to important points for trade and cultural exchange with China and Korea In order to make the differences clearer, we used aerial photos taken in different times. As the result, it became apparent that the land-use and vegetation changed considerably during the period between 1974 and 2002, compared to 1945. In Hiyama, although there were many terraced orange groves in 1974, they were hardly seen in 2002 which seems to have been replaced by wide spread of bamboo forests. Such a change can be suggested as below; the orange trade deregulation in the late 1970s made it difficult to manage the groves and consequently forced to abandon the land. At the same time, bamboo forests were also abandoned due to the lack of role as living and housing materials and thus began overgrow. From the field investigation, it became apparent that bamboo invaded even the broad leaved forests. In addition, the Satoyama coppice forests which have been abandoned for more than 40 years showed the natural succession in which the deciduous trees became stunt and decreased contrary to the vigorous broadleaved evergreen trees growth. In Himeshima, we observed the drastic landscape change as such the terraced fields once stretched from seashore to the summit of the island have almost disappeared and transformed into shrubby forests and bamboo forests due to the population decrease and aging. In the above situation, the local people organized the Hiyama Satoyama Forest Conservation Group five years ago and have been conducting bamboo clearing work. Additionally, from a questionnaire survey, it became apparent that in Himeshima people also hope to restore the former landscape and expect the support for their conservation activity by city dweller. However it is still a partial activity which needs more participants and further development to make it wider and multiple landscape conservation action. To realize the regenerative symbiosis society by utilizing local biomass energy and local food, we suggest it is essential to establish a NPO which involves the local government and the school education system by reforming existing groups.