Carbon fluxes in the atmosphere-plant-soil system

The fourth cluster is characterized by the maximum rate of development by 2050 a sudden increase in the number of C02 sources over this territory should be expected, and at the same time, their number in Europe should decrease. Of course, there is a certain dependence here between the geographical distribution of C02 sources and the geological supplies of fossil fuels. 

The assimilation of C02 by land ecosystems is determined by the difference between carbon assimilation due to photosynthesis and loss of carbon due to respiration. However, the subsequent climatic impact shows itself only in several decades in 

The C02 flux at the atmosphere vegetation cover boundary is determined in many respects by the soil processes involved in organic matter transformation. To better understand the biotic and abiotic mechanisms that control C02 emission from the soil, Jassal et al. (2005) compared measured C02 fluxes in a forest with their distribution profile in the soil of a 54-year-old coniferous forest on the eastern coast of Vancouver. It was established that C02 concentration grows at all depths of the soil layer with rising temperature and humidity. This is explained by soil diffusion reduction and changes in soil ecosystem functioning. It was noted that more than 75% of C02 emitted from the soil was generated at a depth of 20 cm, and almost total C02 flux forms from the 0 cm-50 cm layer. 

Studies by Kondratyev et al. (2004a, b) showed that consideration of the spatial heterogeneity of sinks and sources of atmospheric carbon and specification of the parameters of its fluxes at the atmosphere-land and atmosphere-ocean boundaries raised the accuracy of estimates, but did little to remove either imbalances or differences between carbon fluxes and the dynamics of the change in C02 partial pressure in the terrestrial atmosphere. 

From available, though approximate, estimates, about 1023 g of carbon-containing gases are concentrated in the rocks of the Earth s crust and mantle (lithosphere) (Korstenshtein, 1984 Sokolov, 1971). This mass of carbon exceeds by approximately 104 times the amount present today in the biosphere (over the Earth surface). Between the biosphere and lithosphere there is a constant, very intensive exchange of carbon that is self-regulatory. From the data of Barenbaum (2000, 2002), due to the Le Chatelier principle (Krapivin et al., 1982), the content of mobile carbon in the system tries to attain a stable relationship  

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Figure 3.4. Carbon fluxes in the atmosphere-plant-soil system.

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