Wetlands are essential for global biogeochemical cycles and ecosystem services, with the dynamics of soil organic carbon (SOC) serving as the critical regulatory mechanism for these processes. However, accurately modeling carbon dynamics in wetlands presents challenges due to their complexity. Traditional approaches often fail to capture spatial variations, long-range transport, and periodical flooding dynamics, leading to uncertainties in carbon flux predictions. To tackle these challenges, we introduce a novel extension of the fractional RothC model, integrating temporal fractional-order derivatives into spatial dimensions. This enhancement allows for the creation of a more adaptive tool for analyzing SOC dynamics. Our differential model incorporates Richardson–Richard's equation for moisture fluxes, a diffusion–advection–reaction equation for fractional-order dynamics of SOC compounds, and a temperature transport equation. We examine the influence of diffusive movement and sediment moisture content on model solutions, as well as the impact of including advection terms. Finally, we validated the model on a restored wetland scenario at the Ebro Delta site, aiming to evaluate the effectiveness of flooding strategies in enhancing carbon sequestration and ecosystem resilience.

This deliverable presents a detailed overview of advanced modelling and mapping methodologies developed to evaluate, upscale, and project the responses of wetlands to climate change and restoration activities. It primarily addresses the methods and frameworks intended to enhance the understanding and management of wetland ecological conditions, associated trends, and the land-use pressures influencing them. Methods and tools have been developed to carry assessments that integrate data-driven approaches with process-based modelling components, allowing accurate simulations of wetland ecosystem dynamics under diverse environmental pressures. These applications employ mapping products developed at the site level, drawing from existing methodologies established in the SWOS and EOMORES projects, which emphasize land-use and land-cover change, surface water dynamics, and water quality parameters. These mapping products directly inform enhancements to the LUPLES method and are further scaled up for broader regional applications. Moreover, existing models designed for estimating GHG sequestration resulting from restoration actions have been refined into control models with the dual objective of optimizing restoration costs while maximizing both GHG mitigation effectiveness and biodiversity conservation. Additionally, this report incorporates an integrated modelling framework specifically designed to evaluate and quantify the greenhouse gas mitigation potential of wetlands, as well as the adaptability of relevant ecosystems under various scenarios of climate and land-use change, incorporating the effects of restoration interventions. The relationship among land use, pressure levels, ecological status, conservation-alteration-restoration statuses, carbon storage capacities, and GHG emissions has been addressed. The selection of appropriate decision-making tools incorporates recent conceptual advancements regarding the valuation of nature, specifically comparing the ecosystem services framework (WG MAES) with the Nature’s Contributions to People perspective developed by IPBES.