Microhabitats  creation

The biodiversity of fens has dramatically decreased in the last 20 years. It is due to the lack of mowing and to the vicious circle represented by the water table lowering and the consequent eutrophication caused by the cumulated organic substances nitrification.

Few high-competitive species have survived (Cladium mariscus, Schoenus nigricans, Molinia caerulea) and even if mowing has been restored, the right ecological niches of several specie will not appear for many years.

In order to avoid  this phenomenon and to recreate fair conditions for target species, the project includes - for limited areas - the removal of cumulated vegetal materials and of upper turf layers so as to reach the right water level.

Single tussocks or 10-30 cm high layers of turf will be removed – operating from platforms or during the frozen period – by using a light digger that will not proceed in a uniform way,  sometimes even reaching the gravelly-sandly layers.

Obtained tussocks and turves will be carried and used in the restoring areas, to speed up the colonization process.

These actions will recreate fair conditions – right water levels and pedological characteristics (Ph, available nitrogen) - for Annex II endemic species and for other conservation interest species, once much more frequent in the Resurgences area but now almost extinct.

As for the Armeria helodes and Erucastrum palustre species, this action will create new sites - thanks to specimens ex-situ cultivation – so as to reconnect actually isolated sites and to aid genic exchanges between different populations.

Results

This action allowed the reintroduction in natural environments of many individuals of Erucastrum palustre and Armeria helodes, two steno-endemic species of Community interest, at high risk of extinction.

Were created 14 microhabitats with the help of a small excavator and other 19 proceeding manually.

Two different techniques of intervention were used:

a) Take-out of small clumps of vegetation with the help of a small excavator equipped with small-size bucket. The excavator has moved on a platform to avoid damages to the vegetation layer.

b) Cut flush of herbaceous cover on small surfaces of the fen - about ten square meters - with the use of a mower blade. Creation of holes in the trimmed area using an auger with a small diameter tip. Specimens transplantation into the prepared holes. The average area of treated surfaces is about 10 sqm.

The Armeria helodes and Erucastrum palustre conservation condition can be also deduced from the detailed census done during the vegetation monitoring program.