Pine wilt disease (PWD) represents a major threat to forest ecosystems worldwide. Although PWD is now better understood, effective control measures for this disease have still not been devised. Here, we report several years of field studies on preventative silvicultural control of PWD. Silvicultural control through preventative clear-cutting and the manual removal of logs was implemented between 2005 and 2009 in 16 Korean districts that had newly PWD-infected stands. Preventative clear-cutting of neighbouring asymptomatic pine trees (within a 10 to 50-m radius ofwilt trees) and the removal of felled logs or branches suppressed spread of PWD. Occurrences of PWD wilt pines in districts (city or county) subjected to this silvicultural control method were significantly reduced compared with those in districts using conventional controls (physical or chemical treatment of wilt pine trees). Through silvicultural control, PWD was successfully suppressed in 11 of 16 districts investigated. In contrast, successful control was achieved in only 1 among 18 districts subjected to conventional control. Our results will be of considerable interest to those engaged in the very difficult battle against the global spread of PWD.

The purpose of this study was to explain relationship between community structure and their environment variables in Mt. Hwaak. Samples were collected by 101 plots using ZM phytosociological method and followed by cluster, importance value and canonical correspondence analysis. The forest vegetation classified into 8 community types such as Pinus densiflora community, Berberis amurensis community, Betula ermani community, Betula schmidtii community, Larix leptolepis community, Pinus koraiensis community, Cornus controversa community and Salix koreensis community. Altitude was considered as the highest factor correlated to the community types. Berberis amurensis community and Betula ermani community were located in upper slope area of high elevation, Cornus controversa community and Salix koreensis community in valley area, and Pinus densiflora community in ridge area, respectively.