The spatial distribution of soil-plant formations

Global carbon cycle model and numerical results 201 

Structural changes to the land cover are not exclusively due to human activity. In some regions of the globe, hurricanes introduce considerable changes in the carbon balance of forest ecosystems. For example, in the U.S.A. two hurricanes happen on average every three years, which accelerates the transition of the living biomass of 

Vegetation formation (see Table 3.9) Rate of CO2 assimilation (106tC/yr)  

2 The role of the World Ocean in carbon dioxide assimilation from the atmosphere 

Estimation of the extent to which the World Ocean assimilates C02 from the atmosphere, as in the case of land, is only possible by spatially integrating the difference between fluxes H s and Hc. Table 3.15 gives average estimates of this difference. Even with these rough estimates, we can see the mosaic character of the role of various 

---

All models of the C02 cycle need improvement in the way they detail the spatial distribution of soil-plant formations and in the way they specify exchange processes in the ocean and at the atmosphere-ocean boundary. Accurate parameterizations of all studied elements of the biogeochemical carbon cycle should be synthesized into a single system. Such an attempt was made in the block scheme of the model shown in Figure 3.6. The main sources of C02 are the day-to-day activity of land and marine animals, photochemical reactions, decomposition of dead organic... 

Figure 3.8. The spatial distribution of soil-plant formations over the 4° x 5° geographical grid and their representation by pixels in the GMNSS spatial structure. Identifiers of the types of soil-plant formations are explained in Table 3.9.

---