Stand dynamics of introduced black locust (Robinia pseudoacacia L.) plantation under different disturbance regimes in Korea

Black locust (Robinia pseudoacacia L.) was introduced to South Korea from North America in the 19th Century and was heavily used in the 1960s for reforestation of denuded mountains after the extensive deforestation during the Japanese occupation periods and the Korean War. Nationwide distribution of black locust tended to positively correlate with human population size and/or density of the administrative districts considered. Results from field survey on the representative vegetation types, Quercus acutissima and Q. mongolica communities in lowland and upland, respectively, show that black locust have invaded other vegetation beyond originally planted zones in lowland but not the upland vegetation. Black locust occurs from the bases to summits of mountains in the urban centers, whereas its range is restricted to mountain bases in urban outskirts and rural areas. Although native oaks (Quercus spp.) are usually succeeding black locust colonies, changes to native vegetation are often interrupted by frequent disturbance by human activities, as evident from persistent sprouts and expansions of black locust suckers in the disturbed areas, such as urban center and rural areas. Responses of the black locust plantation in terms of stand dynamics to different disturbance intensities also reflected such trends. Our results suggest a correlation between disturbance regimes and occurrence of black locusts. We recommend incorporating this correlation to the management plan for control of black locust.