Evaluating the Long-Term Effect of Harvest On Soil Carbon Dynamics of Pinus Densiflora Stands in Korea Using Modeling Approach.

Harvest is one of the major disturbances affecting the soil carbon (C) dynamics in forests. However, researches about the impact of periodic harvest on the soil C dynamics are usually limited since they require long-term studies with rigorous control of various factors. Thus, we adopted the modeling approach to determine the long-term impacts of periodic harvest on the soil C dynamics by using the Korea forest soil carbon (KFSC) model. The model can simulate the biomass growth and soil C dynamics after harvest at a stand level using a small number of input data. The simulation was conducted on Pinus densiflora stands in central Korea, and twelve harvest scenarios were tested by altering harvest intervals (harvest for small-diameter log: 50-year, medium-diameter log: 80-year, and large-diameter log: 100-year), intensities (low: 50% and high: 100%), and the residue managements after harvest (collection: 50% and retention: 100% of aboveground residue). We simulated the soil C stock for 400 years for each scenario. As a result, the soil C stocks in depth of 30cm after 400 years range from 49.9 to 52.9 Mg ha^-1, corresponding to -2.6 to +3.2% of the C stock at present. The soil C stock under the scenario with lower intensity or residue retention tends to be higher. Harvest interval effect on the soil C stock depends on the harvest intensity. Longer interval makes higher C stock when the intensity was high whereas an opposite result was simulated when the intensity was low. These results might be derived from the differences in growth pattern and the amount of dead organic matter after harvest in each scenario. The current study could provide preliminary results for the long-term effect of various harvest condition on the soil C dynamics and contribute to the decision making in forest management associated with C account.