ORCHIDEE‐MAN: Incorporating Mangrove Processes in the Global Vegetation Model of ORCHIDEE

Abstract The mangrove ecosystem is characterized by high carbon sequestration rates and plays a crucial role for the exchange of carbon between land and ocean. Understanding the carbon dynamics of mangroves under climate change and human disturbances is therefore essential for quantifying their contributions to global carbon cycle. However, most land surface models do not have a specific module for mangroves, leading to potential biases in simulating the uptake of atmospheric carbon by terrestrial ecosystems and the carbon budget of tropical countries. In this study, we introduced a new plant functional type for mangroves into the land surface model ORCHIDEE‐MICT‐PEAT‐LEAK. We added the mangrove‐specific carbon pools of aboveground roots and a new carbon allocation scheme. We also added the effects of salinity and tidal inundation on mangrove productivity. We then calibrated and optimized the parameters related to photosynthesis, autotrophic respiration, carbon allocation and mortality using data collected from literature reviews. Compared to the original model version, the modified version shows greatly improved performance when evaluated against the observational data sets from field measurements. Specifically, ORCHIDEE‐MAN can generally reproduce the spatial distribution of aboveground biomass density from satellite‐based map, as well as the seasonal cycles of gross primary productivity observed at three eddy covariance flux towers for mangroves. This model version with the mangrove module provides a useful tool for understanding the carbon cycle processes and estimating carbon budgets in mangrove ecosystems. The processes and parameters described here may support the development of mangrove module in other land surface models.