1. Effects of waterlogging and elevated salinity on the allocation of photosynthetic carbon in estuarine tidal marsh: a mesocosm experiment.
- Author
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Li, Ya-Lei, Ge, Zhen-Ming, Xie, Li-Na, Li, Shi-Hua, Tan, Li-Shan, and Hancke, Kasper
- Subjects
WATERLOGGING (Soils) ,SALT marshes ,COASTAL wetlands ,SALINITY ,ABSOLUTE sea level change ,PHRAGMITES australis ,CONDITIONED response ,CARBON fixation - Abstract
Background and aim: Coastal marshes and wetlands hosting blue carbon ecosystems have shown vulnerability to sea-level rise (SLR) and its consequent effects. In this study, we explored the effects of waterlogging and elevated salinity on the accumulation and allocation of photosynthetic carbon (C) in a widely distributed species in marsh lands. Methods: The plant–soil mesocosms of Phragmites australis were grown under waterlogging and elevated salinity conditions to investigate the responses of photosynthetic C allocation in different C pools (plant organs and soils) based on
13 CO2 pulse-labeling technology. Results: Both waterlogging and elevated salinity treatments decreased photosynthetic C fixation. The hydrological treatments also reduced13 C transport to the plant organs of P. australis while significantly increased13 C allocation percentage in roots. Waterlogging and low salinity had no significant effects on13 C allocation to rhizosphere soils, while high salinity (15 and 30 ppt) significantly reduced13 C allocation to soils, indicating a decreased root C export in saline environments. Waterlogging enhanced the effects of salinity on the13 C allocation pattern, particularly during the late growing season. The responses of flooding and elevated salinity on C allocation in plant organs and rhizosphere soils can be related to changes in nutrient, ionic concentrations and microbial biomass. Conclusion: The adaptation strategy of P. australis led to increased C allocation in belowground organs under changed hydrology. Expected global SLR projection might decrease total C stocks in P. australis and alter the C allocation pattern in marsh plant-soil systems, due to amplified effects of flooding and elevated salinities. [ABSTRACT FROM AUTHOR]- Published
- 2023
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