Response of phytoliths in Leymus chinensis to the simulation of elevated global CO2 concentrations in Songnen Grassland, China

Abstract

Measuring the response of terrestrial ecosystems to elevated CO2 concentrations is very important for understanding the effects of global change. In this study, OTC (open top chambers) were used to simulate elevated CO2 concentrations in the Songnen Grassland. As well, phytoliths in Leymus chinensis were extracted to study the relationships between phytoliths and CO2 concentration. The results show the rondel is abundant in Leymus chinensis, while the trapeziform polylobate is rare. When phytolith production is increased, the rondel phytoliths grow bigger and the proportions of the different phytolith types changes under high CO2 concentration. These types include elongate hollow, acicular hair cell, square and laminate and are only observed in samples grown under high CO2 concentrations. All this evidence demonstrates that phytoliths in Leymus chinensis are sensitive to CO2 concentration, and indicate that phytolith analysis may have potential use in the study of global change, identifying different ecotypes of Leymus chinensis and for the reconstruction of paleoatmospheric CO2 concentrations.