Restoration effects influenced by plant species and landscape context in Young-il region, Southeast Korea: Structural and compositional assessment on restored forest

Despite it has been mentioned that the successful restoration in landscape level was achieved in the Young-il soil erosion control project, quantitative evaluation of restored plant communities (Alnus firma as introduced species and Pinus thunbergii as native species) was hardly founded. Light availability, litter and woody debris cover, and forest structure and composition were determined for 500 m2 band-quadrat in three forest types. Abiotic factors of Q. serrata stands, as reference forest, and A. firma stands were similar but not for P. thunbergii stands. There were no significant difference on mean stem density (stems ha-1, H = 3.6, p = 0.162), and the mean basal area of each stand had marginal significance (m2 ha-1, H = 5.7, p = 0.058) among stands as total basal area was higher with the order of A. firma (21.4 m2 ha-1), P. thunbergii (19.8 m2 ha-1) and Q. serrata (16.2 m2 ha-1). Restoration of vegetation structure was more effective in fast-growing and N-fixing A. firma, as introduced species plantation. However, result of MRPP, NMS ordination and ISPAN for herbaceous layer, not for tree and shrub species composition, indicated that restoration of ground vegetation was likely influenced highly from local environment. Propagule availability from landscape context such as connectedness to natural vegetation and management practices in restored isolated stands are available explanations for restoration effects and gaps between restored plantations and secondary oak forest.