6.1. Study case 1: Restoration of an agricultural drained peatland: the case study of the Massaciuccoli Lake Basin in Tuscany (Italy)

From last century, the deep drainage of peatlands due to the increasing land demand for agriculture and forestry as well as the need to improve sanitary conditions (e.g. malaria) has led to remarkable changes in the structure and the equilibrium of those ecosystems. The dehydration of peat body has determined a series of consequences on the physic-chemical properties of peat, such as (i) acceleration of organic-matter oxidation, with a consequent increase in greenhouse gases (GHG) emissions into the atmosphere of up to 25 t CO₂ equivalent ha⁻¹y⁻¹; (ii) increase in NO₃⁻ concentrations in porewater due to higher oxygen availability and the consequent mineralization and nitrification of organic N and (iii) mineralization of organic P compounds and increase of absorbed and Fe-bound P pools. The continual recurrence of these phenomena has negatively affected the land, for example, progressively lowering the soil level (subsidence), increasing nutrient loads delivered to receiving water bodies (eutrophication) and decreasing ecosystem biodiversity and functionality (loss of ecological stability), especially in land reclamation districts. For these reasons, rewetting of drained peatlands has been identified since the mid-1990s as an important mitigation strategy to reverse this self-perpetuating process, which is definitely unsustainable. Our case study is the Massaciuccoli Lake floodplain, located in the Natural Park of San Rossore, Migliarino and Massaciuccoli, which is one of the most important residual coastal marshy areas of the Tuscany (Italy).