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Schütt-Dobratsch
Date du début: 1 févr. 2001, Date de fin: 31 janv. 2005 PROJET  TERMINÉ 

Background Just a few kilometres away from the point where Austria borders Italy and Slovenia, in the Gail valley at Arnoldstein, is one of the most impressive pieces of scenery created by landslides in the eastern Alps: Schütt-Dobratsch (a jumble of rocks and scree from Mount Dobratsch). The area was last hit by a massive landslide in 1348 and the boulders which fell off the mountain cover an area of some 24 km². With its bizarre rock formations and heaps of boulders, mountain pine thickets, Norway spruce and broad-leaved forests, the area today forms a unique refuge for a multitude of animal and plant species, including many thermophilic organisms. The landslide area is also of central importance as a migration route for the brown bear. There is clear evidence that in the course of the last few decades brown bears have been wandering into the Austrian Alps from Croatia and Slovenia via the Schütt-Dobratsch region. There are now 25 to 30 bears in the Austrian Alps. However, the completion of a section of the A2 motorway in 1984, cutting through the southern part of the area, made it much more difficult for the brown bear to cross over into Austria from Slovenia. The ensuing reduced genetic exchange was jeopardising the further development of the small brown bear population in the Alps. Objectives The prime objective of the LIFE-Nature Project was to construct a 150-metre-wide motorway overpass for bears and other fauna in the Natura 2000 area. The motorway runs through a cutting at this point, so there would be no need for any major earthmoving works. Judging by previous observations of the bears in the area, and from experience with a similar structure in Croatia, the project was confident that the bears would quickly start using the overpass once it was completed. This would help reinforce the Alpine population of the brown bear. The project would be accompanied by a number of other habitat improvement measures in the Natura 2000 area, such as converting stands of spruce monocultures, bringing botanically valuable valley meadows back into use, excavating spawning pools, etc. Results The project carried out the following measures: • The A2 motorway, cutting through the southern part of the area, had made it much more difficult for the brown bear to immigrate into Austria from Slovenia. The ensuing reduced genetic exchange was jeopardising the further development of the small brown bear population in the Alps. A concrete bridge over the motorway was successfully constructed and planted with vegetation and trees to make it seem as natural as possible. Although for technical reasons it was only 95 metres wide instead of the original 150, the first bear was observed crossing it in Aug. 2005. Thus a migration corridor has been established which should ensure the future population exchange between Italy and Slovenia on the south side of the motorway and the Austrian Alps on the northern side. • 14.01 ha of valuable meadow types were restored by bush removal and clear-cutting. • 15.09 ha spruce forests were changed into mixed or broad-leaved forests appropriate for the site and their natural succession boosted. • 9.4 ha valuable mountain forest was bought (supplemented by a further purchase of 29.36 ha parallel to the LIFE project) and the spruce pockets within these forests were transformed into natural forest. Because timber exploitation was stopped after purchase, these forests will provide a refuge area for migrating birds. Similarly, by stopping the recurring landslide area rehabilitation actions in the forests(which consists of excavating and removing the debris which is permanently coming down the mountain slope) the LIFE project eliminated disturbance factors, thereby allowing new, rare and valuable pioneer habitats to develop. • Two Natura 2000 sites covering a total of 4,637 ha have been GIS mapped according to habitat types and species and land use; for some habitats, improvement actions were formulated and conservation targets (“Entwicklungsziele”) set. • Through this mapping, two new Annex I habitats were found (9422 and 6510). • The Annex II priority species Rosalia alpina was found in satisfactory population densities. Further management of the area will take into account the mapped occurrences. • A number of species listed in the Birds and Habitats Directives were monitored and their population size, as previously recorded, corrected: • Caprimulgus europeaeus has 40 breeding pairs in the area (and not 10, as assumed before the project) • Dryocopus martius has 15-20 breeding pairs in the area (and not 5, as assumed before the project) • Picus canus has 15-20 breeding pairs in the area (and not 10, as assumed before the project) • Glaucidium passerinum counts 2 to 9 breeding pairs (not known before). • Lanius collurio has 25-30 breeding pairs in the area (and not 10, as assumed before the project). • Annex II species Bupestris splendens found for the first time in Austria Also, first evidence for the area of the spider species Scotina celans and Neon rayi. The monitoring also showed positive trends for certain populations during the project. Thus the Bombina variegata population rose from 100 to 150 individuals, probably due to the creation of ponds and the restoration of former river arms as breeding places for amphibians and dragonflies (including the Annex II species Leucorrhinia pectoralis). The structural composition of butterfly communities changed considerably (towards more endangered species) after the meadow management had started. Finally, there was an enlargement of Liparis loeselii (an Annex II orchid) habitat with 4,000 m²

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