Interactions between the terrestrial carbon (C) and nitrogen (N) cycles shape the response of ecosystems to global change. The limitation of ecosystem C storage due to N availability, and the response of N₂O emissions to environmental conditions and N addition have been intensively studied. The global anthropogenic changes in C and N cycles call for modeling tools that are able to address and quantify essential interactions between N, C, and climate in terrestrial ecosystems. Recently, a growing number of global land surface models provide a means to scale ecological understanding of the nitrogen cycle to regional and global scales with the ultimate aim to investigate the magnitude of nitrogen cycling effects on global biogeochemistry, as well as their indirect consequences for biogeophysical land-atmosphere interactions. In this study, LM3V land surface model was applied within a prognostic N cycle for applicability in South Korea. LM3V was developed by the Princeton-Geophysical Fluid Dynamic Laboratory (GFDL). The model captures mechanisms essential for N cycling and their feedbacks on C cycling : N limitation of plant productivity, the N dependence of C decomposition and stabilization in soils, removal of available N by competing sinks, ecosystem losses that include dissolved organic and volatile N, and ecosystem inputs through biological N fixation. The model also captures many essential characteristics of C-N interactions and is capable of broadly recreating spatial and temporal variations in N and C dynamics. The introduced N dynamics improve the model's short-term NPP response to step changes in CO₂.