Using eco-hydrological modeling to understand hydrological dynamics impacted watershed spatial biogeochemical processes

Hydrological cycle has been serving as a foundation of biogeochemistry, since terrestrial biogeochemical processes are closely interacting with the quantity and quality of water movement. Particularly, the hill slope runoff pathways (overland flow, matrix flow, and macropore flow) and riparian dynamics are key features to identify biogeochemical processes. Traditional terrestrial biogeochemical models are challenged by the high dynamic hydrological processes and lateral transport of water and nutrients. Especially in the water-controlled ecosystem, it is expected that the vegetation dynamics would rapidly interact with water cycle under the influence of hydrologic regime. Here, we developed modules that simulate the carbon and nitrogen cycle, to extend a hydrological model: Penn State Integrate Hydrologic Model (PIHM) based on Biome-BGC. The preliminary model application was tested by data from Harvard Forest Site. The fully-coupled hydrological dynamics were able to drive both vertical and lateral biogeochemical processes, and vegetation dynamics from biogeochemical simulation provided more detailed physics for land surface modeling. The long-term spatial explicit simulation framework will help to explore interactions between water carbon and nitrogen cycles.