Carbon stock in the wetlands of the Po river delta

Deltaic wetlands are among the most varied and dynamic environments on Earth, occurring across all major continents. They provide a wide range of ecosystem services that benefit both wildlife and human communities. One of their primary services is carbon sequestration, wherein the waterlogged sediment conditions slow down organic matter decomposition and allow these ecosystems to store carbon long-term. This is particularly important in the context of ongoing climate change and the increasing anthropogenic pressures affecting coastal environments. This thesis aims to investigate the factors controlling carbon storage in coastal wetlands of the Po river delta. Specifically, it examines the influence of wetland age, water content, sediment grain size, vegetation type, salinity, which also relates to the coastline and freshwater channel proximity, as well as previous land use before marsh formation. Organic matter content was estimated using the Loss on Ignition (LOI) method, and carbon content was estimated via elemental analysis. Additionally, a subset of samples was examined further via laser grain-size measurements. Organic matter content and depth-integrated carbon stocks varied substantially among sites. Organic matter was strongly associated with gravimetric water content, whereas relationships with median grain size and mud content were weak. However, differences in recovered core length limited direct comparison of carbon stocks among wetlands. The goal of this study is to provide a broad assessment of the carbon stocks of the Po river delta wetlands and to improve our understanding of the environmental factors controlling carbon accumulation, contributing to the evaluation of their role in climate change mitigation and coastal wetland management.