Climate change may alter the rate of soil N transformation. Therefore, it is important to investigate how climate conditions and soil properties affect soil N transformation. In the present study, soil transplantation experiments were performed using soils on a xeric south-facing slope and a mesic north-facing slope in cool-temperate broad-leaved natural forests. Soil N transformation rates and leaching between slopes were compared using the resin-core method to clarify whether soil history (soil origins) or current environmental condition (locations) is the most important factor affecting soil N dynamics. The annual N mineralization did not differ significantly among soil from different origins and locations. In both locations, the annual net ammonification in south-facing soils was higher than that in north-facing soils, whereas the annual nitrification of north-facing soil was higher than that of south-facing soil. N mineralization and nitrification in north-facing soil were significantly higher during the growing season. N mineralization in south-facing soil was not significantly different between seasons. The interaction effect among seasons, soil origin, and location on net ammonification was significant. Net ammonification was higher in south-facing than in north-facing soils, and on south-facing than on north-facing slopes during the dormant season, suggesting that environmental change during winter affected the ammonification of south-facing soil. During the dormant season, N mineralization and leaching were not enhanced in soil of either origin at the transplanted locations, compared with the original locations, suggesting that, in this region, snow regime changes might not enhance the risk of N loss from forest ecosystems.
All Science Journal Classification (ASJC) codes
- Ecology, Evolution, Behavior and Systematics