Drought influences the phytolith morphology variation and its occluded carbon of leaves in Dendrocalamus Ronganensis during growing season

Abstract: Being an important carbon (C) sink on Earth, phytolith occluded carbon (PhytOC) has been investigated in various soil-plant systems. Yet, the environmental factor (i.e., drought) is less studied on the variation of phytolith, its relative depositions in plant tissues, morphology variations, and occluded carbon in the soil-plant systems. In this study, we analyzed the monthly variations of phytolith production and phytolith-occluded carbon (PhytOC) in the leaves of Dendrocalamus ronganensis grown on a karst mountain in southwestern China. This study aimed to understand the drought factors influencing phytolith formation, morphology variation and carbon sequestration in plants. Our results showed that the phytolith assemblages and PhytOC between new and old leaves were significantly different, and varied with plant growth stages. The average PhytOC of old leaves and new leaves was 3.2% and 2.2%, respectively. In particular, both PhytOC and proportions of elongate, cuneiform and stomata phytolith in new leaves significantly decreased during drought months (from September to November). This study suggests that PhytOC in plants is closely related to phytolith morphologies, and significantly affected by growth stage and hydrologic conditions of the growth environment. This indicates that we can improve the efficiency of phytolith carbon sequestration in plants and potentially reduce the atmospheric carbon dioxide content by improving the soil water conditions required for plant growth.

Keywords: Dendrocalamus ronganensis; phytolith; phytolith-occluded carbon; soil drought