alkaline fen

The resurgences area Schoenus alkaline fen is a habitat of particular interest for the presence of rare endemic species as Armeria helodes, Erucastrum marsh, Centaurea forojuliensis, Euphrasia marchesettii and a unique series of glacial wrecks Carex davalliana, Carex panicea, Parnassia palustris , Tofieldia calyculata, Primula farinosa, Eriophorum latifolium, Pinguicula alpina, Sesleria uliginosa, Crepis slovenica, Drosera rotundifolia.
The alfaline fen by the fito-sociologic point of view is represented from the association Erucastro-Schoenetum nigricantis Poldini 1973, included into the Caricion davallianae alliance.
The vegetal association is placed on peaty soils, saturated with water extremely poor in nitrogen and phosphorus but rich of calcium and magnesium. The peaty layers (usually 40-60 cm thick) are placed directly on gravel or gravel-pebbly substrata, through which the water table surface and can temporarily raise until up to 10-20 cm. It is generally present as a belt around the deeper areas with Cladium.
Schoenus nigricans is the predominant species and characterizes the vegetation, along with Cladium mariscus, Molinia caerulea, Holoschoenus vulgaris and Juncus subnodulosus.
In more flooded areas, Schoenus and Molinia form dense tussocks, also 60 cm high, that lead the formation of specific niches able to afford a high floristic diversity. The run-offs and the depressions host species more hygrophilous (Sesleria uliginosa, Carex lepidocarpa, Carex panicea, Senecio fontanicola, Tofieldia calyculata, Equisetum fluviatile), while the top of the tussocks may be colonized by species less calciphilous as Potentilla erecta, Drosera rotundifolia and the priority specie Armeria helodes.
In the stretches just saturated by water table, which are dry during the summer season, the sward is more homogeneous and hosts many small size species that need high brightness as different orchidaceae. In these areas there is a lack of endemic species, competitive only on soils continuously saturated.
There are other plants particularly significant that live in association: Senecio fontanicola, endemic species of south-eastern Alps, Spiranthes aestivalis, Orchis palustris, Anagallis tenella, Liparis loeselii.
The floristic richness of this association is currently at risk for various concomitant causes: the lowering of water table, the increasingly frequency of drought periods - causing mineralization of large quantities of organic matter - and the mowing abandonment. The resulting sites eutrophication is locally changing the vegetation, with the disappearance of many rare and valuable species.