Foreword: The French students enrolled in the MSc ‘Agroecology, Soil and Water Conservation’ attend a 6-seminar cycle with the international students. They are asked to introduce the guest speaker and to write back a summary of the seminar. Here is the summary of the fourth seminar (99% of the following text has be written by the students).
The Restoration of a Mediterranean drained peatland: the Massiaciuccoli Lake Basin
Dr. Vittoria Giannini, Sculoa Superiore Sant’Anna (Italy).
Auhors: Lucie and Julia.
The Massaciuccoli Lake Basin represents a catchment area of 11 430 ha and is located in the San Rossore, Migliarino and Massaciuccoli Regional Park. It’s a Ramsar and Natura 2000 site. 46 000 inhabitants live around, and the area is dominated by 5 151 ha of farmlands cropped on peaty soils. This zone faces several environmental problems:
- Land subsidence (2-3 cm/year) due to intense drainage,
- Peat degradation,
- Eutrophication of surface water and groundwater,
- Difficulties in land cultivation (excessive soil moisture).
One way of managing these issues is to use the ability of wetlands to actively reduce the nitrate and phosphate concentration. Three systems made of perennial grass have been tested in these study : Natural Wetland System, Constructed Wetland System and Paludiculture System.
The case study focuses principally on the Natural Wetland System. The research took place from 2013 to 2016 by environmental monitoring methods. The research group could select Phragmites australis and Myriophillum aquaticum as specific species of the Natural Wetland System. Thanks to the diachronic study of the vegetation from 2013 to 2015, an evolution of the land cover of Myriophillum aquaticum (aquatic specie) could be noted. As soon as the restoration of the NWS took his effects, the vegetation cover by Myriophillum aquaticum has decreased while uncovered vegetation has increased.
The second part of the presentation addresses the management of these specific areas. Harvesting the biomass enables to permanently remove the nutrients and contaminants through the export of the plant biomass. It also ensures to have less dead biomass on the soil which represents a possible pest breeding place. The biomass harvest can be performed with a frequency from 2 to 5 years, depending of the economic and environmental objectives. The harvested products can be sold as pellets for domestic purpose (heating), handcrafts, fire resistant wall made with Typha.
This very rich presentation is based on a experimental site set-up on peatlands which are no so common in France. This site enables carrying out various methods of survey: drone, botany, chemistry. The talk ends with a stimulating question on the economic value which can be given to biomass performing ecosystem services (e.g. de-nitrifaction) which positively influences the environmental quality status.