Improving the representation of tropical wetlands in LPJ-GUESS

Sammanfattning

Tropical wetlands are considered to be the greatest source of wetland-associated methane emissions. Yet, their representation in bottom-up modelling approach is oversimplified in many cases, leading to low confidence in current and future attribution attempts. The LPJ-GUESS dynamic global ecosystem model (DGVM) combines a detailed representation of high-latitude peatlands with a primitive placeholder representation of temperate and tropical wetlands. This study aimed to improve the representation of tropical wetlands within this LPJ-GUESS model. The implementation of a seasonal wetland representation was successfully added. Connected to a set of vegetation dynamics and a simple hydrology functionality, the resulting scheme was shown to be capable of distinguishing the upland, floodplains and permanent wetland ecosystems. Calibration with observational data suggests small improvements to the productivity estimation of the model. Implementation of a mechanistic methane scheme was attempted but was ultimately not successful. The conclusion outline further areas of potential improvement to the representation of tropical wetlands and their methane dynamics within the LPJ-GUESS model.