Domestic wood production in Japan is low, and more than 60% of the wood consumed is imported. This is surprising because two-thirds of Japan’s land area is covered by forests. The dominant explanations for this low wood self-sufficiency rate are the lack of forest road infrastructure and the small-scale forest ownership structure. Austria is a country that is similar in topography and ownership structure but has a high wood self-sufficiency rate. Therefore, previous research has compared Japan to Austria. However, these studies did not address basic forest properties in much detail. This study uses national forest inventory data from both countries to assess the forest structures and utilization percentages of the annual wood increment. In contrast to the hypothesis, the results show that the two countries have similar increment rates. In contrast to former studies, the findings indicate that Japanese plantation forests have a higher timber stocking volume than Austrian forests. In Japan, the proportion of the standing volume in the 40–60-year-old age class is much higher compared to the other age classes, indicating an unbalanced growing stock. The results show that the utilization percentage is much higher in Austria (88%) than in Japan (53%). Therefore, the Japanese forest sector has a high potential to increase the harvest of wood.
1 January 2016 in International Journal of Environmental Monitoring and Analysis
The Otomo rice field zone in Rikuzentakata City, Iwate Prefecture was catastrophically damaged by large-scale subsidence and the tsunami that followed the Great East Japan earthquake, which occurred on March 11th, 2011. Electrical conductivity of underground water, bulk electrical conductivity of the soil, and various meteorological elements were observed at a fixed point for eight months. The electrical conductivity of underground water fluctuated irregularly at the beginning of the observation period, temporarily reaching up to 5 Sm-1 at sea level. After some time, an overall decreasing trend prevailed, and when the observations ended the conductivity of the water had dropped to 0.55 Sm-1. The bulk electrical conductivity of the soil also decreased gradually, from 0.4 to 0.3 Sm-1, over the eight months, which is likely linked to the interactions between rainfall and seawater intrusions. The decrease in soil conductivity has been more gradual here than in the regions affected by the tsunami following the earthquake in the Indian Ocean off Sumatra on December 26th, 2004, and in our study area it has not yet decreased to a level that would allow the resumption of rice farming. It is proposed that this difference is a result of the subsidence in Iwate Prefecture.