C.3. Environmental restoration of the SCI Lake Arreo-Caicedo Yuso
The land purchase and its subsequent change in use will be complemented by the following actions
1. Recovery of the natural vegetation
a) Recovery of the gallery forest at the creek of the lake. This watercourse of marked seasonal character shows discontinuous riverside vegetation; small strongholds integrated by some poplar, willows, and shrubbery that comeinto contact with the marsh vegetation. Specimens of small size, two saps at most or cuttings from them, depending on the species, will be planted in the surroundings. This planting will be performed on both banks, along the course of the 800 meters which run through the parcels that are covered by the purchase in action B1. The species that will be planted are Prunus spinosa, Fraxinus excelsior, Salix atrocinerea, Salix eleagnos, Alnus glutinosa, Anemone nemorosa, Ulmus minor, Euonymus europaeus and Corylus avellana.
b) Re-vegetation of the forest mass on the margin of the existing woodland. In the surroundings of the lake, the reed-sedge peat would potentially gradually give way to formations of sub-humid mountain carrascal (9340) sub-Mediterranean gall oaks (9240) and some zones with the presence of Pyrenean oak, depending on the exposure of the terrain. This action proposes planting to reduce the sudden change that is produced between the forest and the crop restoring two areas situated in the boundaries of the carrascal by means of the improvement and diversification of the degraded or non-existent plant covering.
- The develoment of a forest of sub-humid mountain carrascal will be encouraged around the salt water spring by means of the planting of species like Quercus ilex subsp. rotundifolia, Q. faginea and Juniperus communis
- and a forest of carrascal-gall oak transition with Pyrenean oak elements, through planting species like Quercus ilex subsp. rotundifolia, Q. faginea, Q. pyrenaica, Crataegus monogyna and Juniperus communis.
c) Growth will be encouraged by the regeneration of the reed-sedge peat in the closer surroundings of the lake. It should be kept in mind that the result of the topographic study (Action A2) defined the way of restoring the initial soil morphology and the restoration of the habitats of interest to this study. It is estimated that a recovery of 14%, that is to say, 1.5 ha of the surface of the habitats type 7210*, 7230, 1410, 1510* can be reached.
d) Restoration of habitat 62210*. This will be carried out on the surface of the agricultural plots in which the habitats previously mentioned will not be restored (9240, 9340, 7210*, 7230, 1410, 1510*).
2. Erosion prevention
One of the problems that the lake has is the instability of slopes in the northern zone. To avoid landslides the vegetation maintenance is essential in the zone where it nullifies or minimizes the erosive effects and restrains the uses that can favor erosion. Action B1 includes the purchase of two plots of private property that are located in the high slope area, the rest being public property. With this purchase the uses of this land will be restricted. In respect to the vegetation, planting has been ruled out given that it is well-covered by trees with Pyrenean gall oak and holm oak.
3. Control of non-indigenous fauna
a) Fish species: two specific methods will be employed
- Passive fishing with gill nets, with different mesh openings, in the lake basin with deeper waters and electrofishing in the shallow coastal zone with little emergent vegetation.
- Electrofishing on the perimeter of the lake, except in its northern slope, given the instability of this zone and that the waters rise rapidly to a marked deepness.
b) Red crab: Two methods will be employed agains:
- Passive capture by means of utilization of crab pots.
- Direct hand capture with the help of landing nets and dip nets.
4. Regulation of recreational use.
Given the elevated vulnerability of the vegetation that surrounds the lake, the existence of un-authorized practices of water conduction and the introduction of non-indigenous fauna, access to areas of the lake that are currently access-able will be closed-off or made difficult to enter and signs that explain the prohibited access will be installed there.
A new, sole entrance will be created- only for the access of authorized personnel for the management and monitoring task- which will remain closed.
In order to make public use of the N2000 site easier, but at the same time protect its more vulnerable habitats, it has been proposed to ease access to an alternative site, adapting the surroundings of the Shrine to Our Lady of the Lake, with the object of channeling public use. This would require a site separated from the wetland by a neighboring highway and growing areas, in which public use can be concentrated and in this way negative effects on the wetland can be avoided.