MODELING OF SOIL CARBON DYNAMICS AS A PART OF CARBON-CYCLE IN TERRESTRIAL ECOSYSTEMS

Global warming by the increase of atmospheric CO2 concentration is one of the serious global environmental problems. For the investigations on the causes of atmospheric CO2 increase and the precisely predictions of future global warming, it is essential to understand the global carbon cycle among the atmosphere, terrestrial ecosystems and ocean, and to describe it by mathematical models on the basis of ecology and engineering. As a first step for constructing such a carbon cycle model, we previously developed a model describing the carbon exchange between the atmosphere and the terrestrial ecosystems, where the carbon dynamics in soil were significantly simplified as the first approximation. In this work a dynamic model describing the soil carbon dynamics was developed to improve the carbon cycle model for the terrestrial ecosystems. The vertical distribution of soil carbon and the soil carbon content in various kinds of soil were in good agreement with those previously reported in the literature. The total carbon content in soil over the world was also estimated by using the model. It can be said that a model of soil carbon dynamics working as a part of carbon cycle model between the atmosphere and terrestrial ecosystems was established.