Alexander Ivlev

By Alexander A. Ivlev

Part of the book: Advances in Photosynthesis

By A.A. Ivlev

A key role of photosynthesis as a regulator of global carbon cycle dynamics is considered. According to the suggested model, global natural carbon cycle is regarded as a transition of carbon from the oxidative state, presented by carbon dioxide, bicarbonate, and carbonate species, into the reduced state, presented by different biogenic forms, produced in photosynthesis and in the following transformations. Photosynthesis provides a conversion of oxidative forms into reductive ones. The reverse transition is realized via respiration of living organisms, via microbial and chemical oxidations, accompanying transformations of “living” matter after burial. Among them the oxidation of the buried organic carbon by means of thermochemical sulfate reduction in the subduction zone, where lithospheric plates collide, is most important. Photosynthesis is under the impact of the Earth crust processes. In particular, the lithospheric plates’ movement exerts the impact on photosynthesis development via periodic injections of CO2 into “atmosphere–hydrosphere” system during the plates’ collisions. The irregular lithospheric plates’ movement generates orogenic cycles which consist of short-term orogenic period of active volcanism, magmatism, and mountain building and a long-term geosynclynal period of low volcanic activity and quiet development of Earth crust processes. The pulsating movement of plates affects the dynamics and development of photosynthesis, which in turn determines the periodicity of numerous processes in the nature, including climatic cycles, changes in the rate of biodiversity, irregular accumulation of organic matter in sediments, uneven stratigraphic oil distribution, sea level changes, etc. The redox carbon cycle is a self-organizing system due to negative feedback between CO2 assimilation and photorespiration of global photosynthesis in response to oxygen growth. It made carbon cycle to shift to ecological compensation point. In this point, the system becomes sensitive to separate plates’ collisions that results in short-term climatic oscillations.

Part of the book: Applied Photosynthesis