The influence of forest management on landscape structure in the cool-temperate forest region of central Japan

摘要

Comprehension of historical changes in landscape and forest management will provide valuable insights into current ecosystems and biodiversity and will support future management decisions and conservation strategies. This study clarified changes in the forest landscape of the cool-temperate forest region of central Japan from 1947 to 1997. We used a geographic information system to reconstruct past forest landscapes at four times (1947, 1962, 1975, and 1997) based on interpretation of aerial photographs and landscape metrics calculated using the FRAGSTATS software for spatial pattern analysis. Our results showed that secondary forests, the dominant land use in 1947, decreased greatly in area and became more fragmented, whereas coniferous plantations, which occupied approximately 20% of the total land area in 1947, became the dominant land use (almost 40% of the total land) by 1997. The young coniferous plantations have been established at increasing elevations over time and were mainly created by conversion of secondary forest until 1975. The number of young coniferous plantations and their patch spacing depended on the type of forest management. In the study area, landscape structure changed in response to changes in management of national forests, especially the expansion of afforestation in the 1950s and 1960s and changes in harvesting systems.