The Nivolet CZO is located in the Gran Paradiso National Park, in northwestern Italy (45°25’ N, 7°34’ E). The park was established in 1922 for the protection of Alpine ibex (Capra ibex) and more generally of the Alpine ecosystem, and it covers a total area of 720 km2. The Park is entirely composed of mountainous terrain with woody areas; Alpine pastures, Alpine tundra, moraines, bare rocks, cliffs, lakes and glaciers account for almost 60% of its area. The Park includes five valleys in two neighbouring regions of Italy, namely Piemonte and Val d'Aosta. The Nivolet CZO (2500-2800 m amsl) is located in the Nivolet Plain in the high Orco and Valsavarenche valleys.
The CZO site is located in the Alpine tundra of the Nivolet plain. Here, we have installed two eddy covariance stations, soil probes and stream discharge probes, and during summer we conduct regular samplings of carbon fluxes with the flux chamber method together with soil and water chemistry and isotopic sampling, soil profiling and biodiversity surveys. On the Nivolet Plain, the coexistence of different parental material within the same watershed allows for the study of CO2 fluxes from soils of different geological origins, embedded in similar environmental conditions. In particular, we selected four measurement sites, each with size of about 40x40 m2, characterized by soils developed on carbonate rocks (Ca), gneiss (Gn), glacial deposits (Gl), and alluvial sediments close to the valley floor (Al).
Goal of the Nivolet CZO is to study the functioning of a high-altitude, Alpine tundra Critical Zone, considering limiting factors such as soil moisture, the dependence on the geological matrix and the spatial-temporal heterogeneity of the carbon and water fluxes. Longer-term goal is to assess the response of high-altitude CZ to climate and environmental change, including deglaciation processes.