Simulation of Potential Vegetation Distribution and Carbon Cycle in Northeast China from 1997 to 2010 by LPJ-WHyMe Model

The potential vegetation distribution, the net primary production (NPP), net ecosystem production (NEP), burned area, carbon emissions from fires, soil temperature, and soil moisture in Northeast China from 1997 to 2010 was simulated by using a high-resolution climate-driven field and global dynamic vegetation model, i.e., Lund-Potsdam-Jena Wetland Hydrology and Methane (LPJ-WHyMe) model. The LPJ-WHyMe model is characterized by the capability to describe the physical processes of freezing and thawing, as well as the humidity and temperature of multiple layers in the soil. The five main plant functional types in Northeast China are temperate broad-leaved summergreen tree, boreal needle-leaved evergreen tree, boreal needle-leaved summergreen tree, boreal broad-leaved summergreen tree, and C3 perennial grass. During the period under study in Northeast China, the average value of NPP is 376 g(C) m^-2, ranging from 324.15 g(C) m^-2 to 424.86 g(C) m^-2. The introduction of the mechanism of fire further improves the simulation capability of the LPJ-WHyMe model for NEP. The average value of NEP is 42.36 g(C) m^-2. The annual average burned area is 0.84% and the carbon emission from fire is 42.41 g(C) m^-2 in Northeast China. Overall, the model overestimated the burned area and carbon emission from fire. Moreover, the model still has some limitations in the simulation of fire in Northeast China. A positive correlation between soil and air temperatures is observed in Northeast China, and the correlation in each layer decreases with the increase in depth. A positive correlation between soil moisture and precipitation and a negative correlation between soil moisture and air temperature are observed in Northeast China. These results show that the LPJ-WHyMe model is effective in simulating the potential vegetation distribution and carbon cycle in Northeast China.