TAKASHI OYABU

Japanese black pine (Pinus thunbergia Parl.) is widely planted as a major component of coastal forests, but poor growing conditions and lack of management affect growth of naturally regenerated and planted of Japanese black pine. This study was conducted to clarify the growth of planted and naturally regenerated Japanese black pine and the distribution of coastal plants by focusing on the stand environment in the gaps of a Japanese black pine forest and to obtain information about the maintenance of a coastal black pine forest where coastal plants are distributed. The study site was Keino-Matsubara (Awaji Island, Hyogo Prefecture), designated as a National Site of Scenic Beauty. The survey method was to identify the gaps with GPS and create polygons in ArcMap to measure the area of the gaps and its distance from the coastline. It was found that the gaps with coastal plants were distributed near the coastline, and gaps with naturally regenerated trees were distributed inland. The height growth of planted black pine was much higher than that of naturally regenerated black pine. Accumulated illumination was higher at the center of the gap and the forest edge located north of the gap.

VR (head-mounted display) is a tool that allows you to experience a three-dimensional space. By using VR to evaluate green spaces, it is possible to evaluate them as if they were real spaces. In this study, we aimed to understand the spatial recognition characteristics of VR images of green spaces, and focused on the understanding of spatiality, the reproducibility of reality, and the effectiveness of the montage method. The method was to evaluate green spaces using VR, photography, and field evaluation, respectively, and compare the results. First, we compared the VR evaluation with the photography evaluation in terms of spatial understanding. As a result, we found that VR is superior to photography in expressing three-dimensionality. Also, regarding the reproducibility of the scene, we found that VR is superior in recognizing close view and middle distance view, and that there is a tendency for the difference in evaluation to be greater in sunny weather than in cloudy weather. In addition, when we showed the montaged images in VR and photos, both showed similar reactions regarding variability. Therefore, it can be said that the use of VR in the evaluation of green spaces is suitable for the evaluation of close to middle distance view and evaluation in fine weather.

In order to understand changes in the use of bamboo forests by wild boar, the count of the bamboo shoot feeding marks by wild boars, the position of culm, diameter of culm and a stand age-structure survey were conducted in Awaji Island from 2017 to 2018. Edible bamboo shoots appear on the ground in spring, but we found that wild boar has dug the soil and eaten bamboo shoots before the end of October. In November the number of eaten bamboo shoots accounted 0.1 to 0.7/100m²/day. The total number of the eaten bamboo shoots reached 10 to 15 /100m² during this month and this value was almost equal to the number of current-year culm appeared in the next spring. It is considered that wild boars severely affected to the regeneration of bamboo forest.