Abstract
We examined the effects of site conditions in a pine wilt disease forest on the distribution of regenerated Pinus densiflora. We established 111 plots (5 m×5 m) in the forest and investigated the number of the current-year seedlings, other seedlings (height [H]<0.3 m, age ≥ 1 year), saplings (0.3 m≤ H<1.3 m), and juveniles (H ≥ 1.3 m). We also measured the basal area of the trees (H ≥ 1.3 m), their distance from seed trees, coverage of understory vegetation, canopy openness, thickness of the A0 layer, and degree of slope in each plot. We found a high number of regenerated Pinus densiflora in sites with poor understory vegetation, and thin A0 layer. With the development of Pinus densiflora stands after the establishment of seedlings, the intensity of competition with the understory vegetation increases and light conditions decline owing to canopy closure of upper. story trees. In order to recover Pinus densiflora forests, it is necessary to establish a system to manage upper. story trees and understory vegetation according to the stage of forest development and to maintain an appropriate environment for the growth of regenerated Pinus densiflora.
