Research progress and forecast of phytolith-occluded organic carbon stability in soil

Abstract

As an important long-term terrestrial carbon fraction, the phytolith-occluded organic carbon (PhytOC) has become an important mechanism in the long-term terrestrial carbon sequestration. The contribution of PhytOC stability to the global terrestrial soil carbon pool is much greater than PhytOC stocks. The paper reviewed the formation mechanism and characteristics of PhytOC, the significance of studying the PhytOC stability, and the determinants of the PhytOC stability. PhytOC produced from different types of vegetations had significantly different stability. PhytOC produced from the same type of vegetations but under different growth environments also had different stability. The PhytOC in ancient soil was more stable than that in young soil. The morphological combinations of phytolith in plants were able to respond sensitively to saline-alkali concentrations and pH values in soil. The humidity and precipitation could affect the quantity, size, morphology, assemblages δ13C and δ18O of phytolith. The smaller the Si/Al ratio of phytolith was, the higher the stability would be.[Ch, 1 tab. 90 ref.]