Passive Restoration Achieved through Natural Processes over 70 Years in the Korean DMZ

The Korean Demilitarized Zone (DMZ) is an area where human disturbance has been strictly restrained for about seven decades since 1953. As a result, compared with rural and urban areas in Korea with similar ecological conditions, the landscape structure of the Korean DMZ today shows a big difference in that it has a riparian forest and lacks any of the artificial landscape elements, such as agricultural and residential areas. The vegetation maps made in the 1950s and those made in recent years of a model site that extends throughout the DMZ, the Civilian Control Zone (CCZ), and adjacent rural areas show that successional changes in the DMZ and CCZ areas are remarkable, while changes in the rural areas are not clear. Rice fields have been replaced by riparian forests, whereas young forests in areas previously subjected to excessive use and pine forests have been replaced by broad-leaved forests. Among the three landscape elements that changed, it was found that riparian zones, where natural disturbance is usually frequent, could mitigate the impacts of human disturbance and restore the original features of nature sooner than any other elements. The results of analyses on landscape change that focused on rice fields before the Korean War also showed similar results: most of these fields had turned into riparian vegetation. Stand ordination of riparian vegetation investigated in the CCZ, rural areas, and urban areas showed clear differences in species composition and diversity among regions. In this study, we confirmed the passive restoration of the Korean DMZ and CCZ through natural regeneration processes as a result of restricted human disturbance over a period of about seven decades.