Wildlife Conservation Forested Landscape in the Ota River Watershed, Hiroshima

In Japan, wildlife particularly in watershed area is threatened by extensive impact of human activities. As a result wildlife intruded into human settlement as well as agricultural land, which caused conflict between human and wildlife. To overcome the conflict, effective mitigation to ensure the sustainability of a particular area is necessary. Nevertheless, the relationship between wildlife disturbances and changes in land use must be understood. Thus, the objective of this study is to present the current status and trends of wildlife disturbance and changes in land use as Ota River watershed of Hiroshima Prefecture, Japan as a case study. Results revealed that wild boar was the most disturbance species represented about 73% of total disturbance in the period between 1981 and 2002. Generally, in other species such as sika deer and Japanese monkey, the percent of disturbance was not much changed over the period. Landscape pattern analysis showed that fragmentation (measured by number of patches and mean patch size metrics) increased in the watershed between 1994 and 2000. However, heterogeneity (measured by Shannon's diversity index) of the watershed was almost the same in the two temporal years. Correlation analysis revealed that changes in wild boar disturbance were significantly influenced by changes in forest area (p<0.01). Analysis in 15 town/wards in Ota River watershed showed that by 2000 forest was the major land use except in Nishi-ku, Fuchu-cho, Naka-ku and Minami-ku. In conclusion, fragmentation of the Ota River watershed was an important factor affecting wildlife disturbance especially wild boar. To minimize and control the disturbance, maintenance of existing natural habitats is vital for conserving the watershed biodiversity and ecosystems.