The end of the cutting activities as a consequence of the abandon of the remaining agricultural activities in the areas surrounding the peat bogs, and the decreasing level of the water layers due to the presence of a drainage channel and the consequent increase in the oxygenation of the surface peat layers, their mineralisation and the release of nutrients have all led to the stable growth of the common reed (Phragmites australis).

These graminaceous plants, typical of the vegetation growing in damp environments where they create the cenosis defined “reedbeds”, are particularly resistant and invasive, leading to the progressive replacement of more typical peat bog area species characterised by shorter root systems (in particular Schoenus ferrugineus, included in the national and regional “red list”) with the consequent impoverishment of the plant composition in these sites in terms of both quality and quantity. The uncontrolled growth of Phragmintes also leads to the progressive drying up of the soils and the transformation of the damp environments into relatively drier meadowlands. The persistence of this situation then promotes the invasion in from the edges also of tree species (notably Picea abies, Pinus sylvestris and sometimes, though rarer, Abies alba, Betula spp., Sorbus aucuparia).

This threat is particularly felt on the slopes of the Val Mauria marsh, where Phragmites is clearly dominant, and also in a large area of the sector uphill from the Val di Ciampo peat bog. In the areas below this, the reed invasion can be seen only in the most humid and mineral-rich areas, where the speciesCarex lasiocarpa (slender sedge) grows.