Abstract
Since the 1980 s, the forest cover type around Kyoto City, i. e., Pinus densiflora, has largely changed in urban areas because of severe damage due to pine wilt disease. In order to clarify the recent dynamics of the damaged forests, in 2007 we resurveyed four plots that had been surveyed in 1997 and examined the changes of the stand structure in these plots during a 10-year period. The broad.leaved forest evolved from damaged P. densiflora areas in 1997, and the species diversity declined during the decade. Although many P. densiflora seedlings were found in the degraded forests for lack of tall trees, they were shorter in height and fewer in number than sub-trees. From the above findings, it can be concluded that the P. densifloraforest could not recover under natural conditions. The pine wilt disease spread to the high altitude areas, suggesting that degraded forests may extend to other areas. In order to recover P. densiflora in these degraded forests, it is necessary to exclude sub-trees when many P. densiflora seedlings are survival, and other forest operation is necessary to promote the regeneration when P. densiflora seedlings are few.
