Assessing Carbon Stock and Sequestration Capacity of Phragmites australis Using Integrated Destructive Sampling and Remote Sensing Approaches in Arid Environments

Phragmites australis (common reed) is a resilient wetland species providing key ecosystem services, including carbon sequestration. However, its carbon storage potential in hyper-arid environments remains insufficiently quantified. This study develops an integrated framework combining destructive sampling and remote sensing to assess biomass distribution and carbon stocks in Oman. Results show that destructively measured AGB correlates only weakly with reed height (R² = 0.15), indicating that height alone is not a reliable standalone predictor of biomass in this system; an initially high fit (R² ≈ 0.99) reflected the mathematical dependence of the height-based allometric equations on their own input variable rather than genuine predictive validity. While predictive models based on dry biomass and TOC showed moderate to low performance (R² < 0.16), vegetation indices derived from remote sensing demonstrated high accuracy in estimating spatial biomass variability. Carbon stock estimates ranged between ~0.36 and 1.95 kg/m² depending on the method used. While localized allometric models showed limited predictive power due to high variability in tiller density, vegetation spectral indices demonstrated high accuracy (R² = 0.78), highlighting remote sensing as a viable tool for spatial carbon assessment in arid wetland ecosystems. These findings highlight the potential of integrating field-based and remote sensing approaches to improve carbon accounting in arid wetlands. The study provides a scalable framework for ecosystem-based carbon assessment and supports the role of P. australis as a nature-based solution for climate mitigation in water-stressed regions.