Natural habitats restoration
The restoring actions include the creation of different habitats (alkaline fens, Cladium mariscus calcareous fens, Chara oligotrophic waters, Molinia wet meadows) so as to recover the environmental mosaic that distinguished these areas before the great land reclamations and that reflected the different height of the local water table. The hygrophilous habitat re-creation needs water table surfacing, at least for a part of the year (alkaline fen) or for all the year (Cladium fen intermixed with Chara pools).
Then, after the hydraulic reclamation, ground removal is required until right hydraulic conditions are reached; these conditions are similar to those that originated alkaline fens: water table that flows to the surface through gravelly-sandy layers.
The chemical fertility excess - caused by decades of farming and preventing the growth of oligotrophic vegetation - and most of weedy species seeds can be weeded out through ground removing. Water and fertility conditions for the different vegetal associations could be created by carrying out excavations at different heights from the water table, so as to remove thicker and thicker top-soil layers.
The alkaline fen reconstruction is, of course, a long-term goal; the short-term aim is to restore the right environmental conditions for peat formation.
Excavations create primitive (without organic substances) soil conditions and only some fen species will be able to grow in the new habitats. Mowing and scrub-clearing materials, sometimes integrated by garden compost, are used to shorten these settling times and to re-introduce seeds or seedlings of nursery-grown typical species.
The organic substance lack does not cause negative effects to the Cladium mariscus restoration, because its roots – also in natural conditions – are anchored to gravelly layers.
This method, even if the removed top-soil layer is less thick, is also used for wet meadow restoration. It is always functional to obtain satisfactory hydraulic conditions (waterlogged grounds for almost a part of the year) and to reduce ground eutrophication.
Grounds involved in the restoration are generally corn cultivated and heavily fertilized so, without a soil fertility reduction, it is impossible to recreate strong oligotrophic Molinia local meadows.
Furthermore, the quantity of reproductive organs (rootstocks, seeds) of weedy species requires one or more agronomic containment methods, such as the deep tillage, to make unpolluted layers come to the surface, one or more cultivation cycles, with wintry cereals or fodder graminaceous plants without fertilization, or repeated superficial tillage, at least for a growing season.
After the soil preparation and, if needed, after the grinded straw integration, the ground could be sowed – using a tractor mounted fertilizer hopper - with a mix of local site-suited species, composed of seeds coming from mesophilic meadow threshing and from nursery cultivation integrated, if needed, with commercial graminaceous plants.
Sowing is then integrated with nursery pot-grown specimens of endangered species and habitat characteristic species.
The restoring actions have affected about 20 hectares composed by meso-hygrophilous grasslands (7 ha) and alkaline calcareous fens (13 ha).
The action of restoring the natural state and its functions was made up of different temporal phases: land acquisition, surface excavation and reshaping, preparation of the seedbed for the restoration of grasslands, sowing and grafting of the specimens produced in the nursery. Other farming operations will be made later in time. By now it is possible to observe various degrees of nature habitat reconstruction of the past restorations actions. The most well-established one dates back some 10 years ago and was made in an earlier LIFE project.
With regard to the geomorphological remodeling about 75,000 cubic meters of excavated soil were moved.
Besides sowing flowers and grasses several samples of species were transplanted ; They were grown in the nursery; they are typical of wetlands and fens and often also very rare.