Landscape Changes in Japan Based on National Grid Maps

Abstract

Landscape changes in Japan based on a national grid map were examined adding current data. For detecting changed regions, we classified all of the prefectures in Japan based on naturalness to know the land use characteristics. The number of cells and percentage of degree of naturalness and limited habitats, such as wetland and tidal land decreased showing nature distraction in Japan. The area of secondary Pinus densifloraforest as representative vegetation in rural landscapes also decreased, which may be dieback due to pine wilt disease and ecological succession. Landscape types (or land use) based on special characteristics of naturalness were classified into six groups; natural forests, secondary forests and grasslands, secondary forests and plantation, agricultural fields, and urban areas. Five prefectures saw and change to plantation type from agricultural field type during 1990s. Japan was shown to have urbanization and decreasing habitat complexity, and pine wilt disease and abandoned rural landscape also led to decreasing Japanese representative cultural landscapes. These land uses and management of landscape led to changes in habitat environments with decreasing habitat complexity, ultimately having an effect on biodiversity, now an important national environmental interest in Japan. Therefore, landscape planning and management have to work to halt the decrease in habitat complexity and quality.