The Jeongseon Alpine Center, a degraded forestland, has a very unique soil feature as it was filled with soil cut from the nearby area and has not yet been rehabilitated since the end of the 2018 Winter Olympics. Therefore, this study attempted to identify a way to establish a stable and efficient planting groundwork to successfully restore this distinctive region. Six different planting groundworks, control, biochar, leaf-mold, mulching, tillage, and polyacrylamide treatments were constructed in September 2020. Soil-related indices have been tracked while the growth and physiological responses of planted Pinus densiflora (Pd) and Larix kaempferi (Lk) seedlings were monitored until May 2022. Mulching had 2–4 times the average SWC when compared to the control. Simultaneously, there was the least variation in soil temperature change, and total soil loss was only 0.05 ton/ha. Similarly, the leaf-mold had a relatively high SWC, and soil fertility increased, while total soil loss was 6.37 tons/ha, indicating a high trend in line with biochar. The Pd leaf-mold had the highest in Amax, E, gs, and Jmax. Furthermore, following the leaf-mold, mulching showed the second-highest photosynthetic indices in general, and the height and DRC also demonstrated favorable results in the above two treatments. Mulching had 1.6 to 2.2 times higher than the control group in PIabs and PItotal, which represent photosynthetic vitality, so the impact on environmental stress was thought to be less than that of leaf-mold. The mulching of Lk showed the greatest growth and physiological responses, Nonetheless, the photosynthetic indices were rather low when compared to Pd, with no discernible differences across treatments. As a result, the considerable effect of the planting groundwork method could not be demonstrated. Therefore, in the case of Pd, the leaf-mold showed the best growth and physiological response. Nevertheless, in terms of soil temperature maintenance and soil loss for slope stability, mulching is assessed to be the most ideal planting groundwork method.

In order to determine the suitability of reusing the sediment deposited in the upper part of the dam as soil for growing forest products, a total of eight treatment plots were formed by mixing cultivated soil, compost, and biochar with the sediment in a volume ratio. Generally, the soil fertility of SS100 was relatively lower than that of CS, with Av. P2O5 being only 22%. SS70 and SS50 increased soil physicochemical properties including OM, exchangeable cations, CEC, and BS by 1.1–2.9 times more than SS100, thus, A. scaber Thunb. treated in SS70 and SS50 showed increased photosynthetic parameters including A, Vcmax, Jmax, and the growth characteristics, especially in the aboveground part, were 20% and 31% higher than the SS100, respectively. Furthermore, A. scaber in CS, SS50, Bc10, and Comp had higher PIabs, DFIabs, and SFIabs while maintaining lower VK/VJ after 10 days of drought stress, Comp and Bc10, in particular, had a high Y(NPQ) and a low Y(NO). Bc5 and Bc10, revealed no discernible differences in soil physicochemical properties, nonetheless, A. scaber in Bc10 demonstrated relatively high drought tolerance. Overall, CS, SS50, and Comp had relatively well-balanced plant growth, and drought tolerance was found to be higher in CS, Comp, SS50, and Bc10, which is thought to have higher water-holding capacity and soil fertility. As a result, if appropriate treatment methods are established, such as mixing sediment soil with cultivated soil at a one-to-one ratio or adding compost, increase the public value of forests by promoting activities such as watershed conservation, soil runoff prevention, and reducing the financial burden associated with sustainable forestry management and SS50 is recommended as the most cost-effective method.