We censused herbivory on Cirsium lucens var. opacum by sika deer at Katsuragawa, Shiga Prefecture, Japan, in 2006. Of these plants, 30-60% had leaf damage and 46-70% had capitula damage. There was no difference in herbivory among the three habitats. Two plants decreased about 30-50% in height from 1997 to 2006. Bombus diversus, which was a common pollinator in 1997, was not found in 2006. The diversity or density of pollinators possibly decreased between 1997 and 2006. Seed set has possibly declined due to herbivore damage and pollinator decline.
The environmental preservation investigation conducted by the Japan Green Resources Agency has a number of shortcomings. In addition, the rationality of the plan, in general, has been questioned by concerned citizens. As a result, a political movement requesting withdrawal of the plan has begun, with citizens cooperating with scientists. What stance should ecologists take in relation to this movement? Let us consider this problem as a case study.
The western lowland of Yakushima Island, the World Natural Heritage area, is covered by broad-leaved evergreen forest subjected human disturbance, such as cultivation and wood charcoal production. However, details of the forest utilization remain unclear, because most of this area has been owned privately with no available track records for land use. Comprehension of the past human impact is required to understand the current forest condition and to develop an effective conservation scheme. We conducted field work and literature survey, including interviews with local people, in order to review the history of forest utilization in Han-yama and Kawahara sites in the western lowland of Yakushima Island. Results of literature survey and treering core analysis suggested that people appeared to first colonize these sites around 1900 to undertake cultivation, wood charcoal production, and camphor distillation. According to information gleaned from local people as well as aerial photos taken in 1947, areas totaling 32.2 ha in Kawahara have been clear felled for military purposes in the early 1940s. From the scattered distribution of abandoned charcoal kilns in the gaps of logged areas shown in aerial photos, it was deduced that almost the entire area of Han-yama and Kawahara sites experienced logging of varying intensity for charcoal and wood pulp between the 1940s and the end of the 1950s. Except for the road construction in 1967, these sites have been free from organized logging since around 1960.