In a previous paper, we modified some sub-models of BIOME3 to be applied to 1×1 km mesh data in order to increase the accuracy of simulation.
Using this modified model, we estimated potential natural vegetation distribution under climatic change using 4 types of GCM experiment data. GCM data that can be used presently have rough spatial resolution, so it is difficult to estimate the effect of climatic change at a local scale. Therefore, we used GCM data around Japan that was interpolated to a 10×10 km mesh.
We calculated the NPP, and predicted the distribution of potential natural vegetation and its vulnerability for the 2020s, 2050s and 2080s. Results from the simulation indicated the possibility of 60-100% increase of NPP in the 2080s. The increase in NPP was explained by the increase in air temperature and the concentration of CO2. Potential natural vegetation in Japan would be affected over a wide area by climatic change. In particular, the alpine plants/subalpine conifer forest area would decrease. In mixed forest in the Hokkaido area, where broad-leaved deciduous trees and conifer trees coexist, broad-leaved deciduous trees would become dominant. Broad-leaved evergreen forest area would expand, and the subtropical forest would to a prior species along the coastline of western Japan.