Changed land management policy and the emergence of a novel forest ecosystem in South Korea: landscape dynamics in Pohang over 90 years

Ecosystem management in South Korea dramatically changed in the early 1970s, shifting from historical utilization of natural resources to a strong management system that included forest promotion and restoration. The socio-economic and biological context underpinning this effort and the ecological consequences of this new policy have not been studied in South Korea. We analyzed landscape dynamics over a 90-year period (1918–2005), with particular attention to forest soil erosion, by using historical map and satellite images in Pohang. Our analysis revealed a dramatic increase in total vegetation cover (from 10,006.9 ha in 1918 to 17,868.7 ha in 2005) and an increase in the developed area. Meanwhile, the amount of barren mountainous area declined, shrub vegetation almost completely disappeared from the given area, and the salt marsh in the estuary completely disappeared. Mean soil loss declined from 12.6 ton ha−1 year−1 in 1973 to 0.2 ton ha−1 year−1 in 2005. A gradual landscape simplification occurred during the 90-year period. Socio-economic changes were the most important factor contributing to forest growth in South Korea. Various biological factors, including the absence of apex consumers due to their local extinction in the late 20th century, likely accounted for the rapid landscape transition. The new land management policy in South Korea resulted in the emergence of a forest ecosystem that is novel to this region and differs markedly from the historical environment, with a changed spatial arrangement of landscape elements and species assemblages.