Expansion of vegetation dominated by Ilex pedunculosa at forest sites that had been affected by pine-wilt disease has been observed in Kyoto, and there is aconcern that it might lead to a reduction in the capacity of the forests to influence soil, water, and biodiversity conservation. Moreover, further expansion of I. pedunculosa forests might occur at forest sites that had been affected by oak-wilt disease. In this study, we aimed to understand the current situation of I. pedunculosa forests expansion by analyzing the relationship between I. pedunculosa and site conditions. In addition, the possibility of expansion of I. pedunculosa at forest sites that had been affected by oak-wilt disease was also predicted. Fifty-three plots (10×10 m) were established at Kyoto Takaragaike Park (96.25 ha), and a tree census (diameter at breast height and height) was conducted for all trees more than 1.2 m. The site conditions of the plots were also investigated. The results showed that I. pedunculosa tended to be established on convex and silted sites with residual deposits ; such sites comprised 13.66 ha (14.1% of the study site) of the study area. To evaluate sites dominated by Quercus serrata or Quercus variabilis with a relatively large number of I. pedunculosa trees at the understory,5.95 ha (6.18%) were selected for Q. serrata and 3.92 ha (4.07%) for Q. variabilis. Since both areas were relatively small, the possibility of expansion of I. pedunculosa forests at sites that had been affected by oak-wilt disease might be small.

Designing an appropriate consensus building process among various stakeholders is one of the most difficult issues to be dealt with when establishing a sustainable management plan that addresses conflicting opinions about the preservation and utilization of forests. The purpose of this paper is, first, to describe the conflicts that have arisen with regard to the preservation and development of the subtropical Yambaru Forest on Okinawa Island, and, second, to analyze the process the authors employed to construct the consensus building process for the “Forest Zoning Plan in Yambaru-Kunigami Village”on Okinawa Island. Serious conflicts were settled using the notion of ʻsoft zoning,ʼin which the authors used a variety of GIS data, which described not only ecological and infrastructural aspects of the area, but also historical and cultural information. The authors made use of the notion of ʻsoft zoningʼduring Zoning Committee meetings and town meetings, and succeeded in mitigating the conflicts, and building a consensus.

Stand structure of a 60-year-old secondary forest and a mature non-clear-cut forest were compared in subtropical lucidophyllous forest in the Yambaru area of Okinawa Island. A first dominant species, Castanopsis sieboldii showed a higher stem density in the 60-year-old secondary forest than that in the mature non-clear-cut forest. However, stem density of C. sieboldii with diameter at breast height ＞25 cm in the 60-year-old secondary forest was less than half of that in the mature non-clear-cut forest. The stem size distribution of C. sieboldii had not recovered at 60years after logging. A secondary dominant species, Schima wallichii, showed lower stem density in the 60-year-old secondary forest than that in the mature non-clear-cut forest. Additionally, the sizes of regenerated Distylium racemosum were still quite small, and Quercus miyagii had rarely become established in the60-year-old secondary forest. The stand structure was significantly different in the 60-year-old secondary forest compared with the mature non-clear-cut forest. The species richness was obviously higher in the mature non-clear-cut forest. Mature non-clear-cut forest remaining in the Yambaru area of Okinawa Island is limited and fragmented. Despite this situation, the ecosystems and their biodiversity are still intact and receives praise worldwide. Land managers need to manage conditions in both mature non-clear-cut and secondary forest appropriately, with the goal of maintaining and restoring the ecosystems and their biodiversity.