The Accona Desert refers to a hilly area in the Siena province of Italy, within the municipality of Asciano [43°14'4.30"N; 11°33'37.48"E]. The term is often used to include the Biancana site of Le Fiorentine - Leonina [ 43°17'32.95”N; 11°26'54.07"E]. Despite its name, its climate is Mediterranean, with a hot, dry summer and almost 800 mm/y of rain (Csa Köppen climate classification).
A real desert has never existed here. However, there have been temporarily severely eroded areas, more properly called "badlands".
Two main types of badlands[1] can be found in the area of the Crete Senesi, the Valdorcia, and the Volterra areas of Tuscany: Biancana (from Bianco, white, due to the light color of the clay and of the saline efflorescence) and calanco (local name for a type of gully or ravine). Both are linked to gully erosion processes, the former intermingled mainly with subsurface erosion and the latter with mass movements. Biancanas can also be found in Basilicata and in Calabria. The calanco landscape is common all along the Apennines and in many parts of the Alps. Both calancos and biancanas were used as grazing ground, with an almost annual burning of the vegetation to remove brush and favor herbaceous cover more palatable for sheep, goats, and cattle. Both practices were abandoned in the 1990s to favor measures to preserve biodiversity and geo forms under the EU Natura 2000 program. Conservation has almost stopped erosion in both types of badlands and vegetation now covers the majority of the area that was once bare slopes. As there is a strong interrelationship between vegetation biodiversity and erosion/deposition processes, biodiversity is also threatened and the biancana landscape is forecast to disappear entirely within 20–40 years as brush cover expands.[2][3][4] Spots where the traditional forms can still be observed are scattered in the Crete Senesi and the Valdorcia, included within the quadrangle of vertices [43°16'10.58"N; 11°15'59.30”E], [43°18'28.68”N; 11°39'4.92”E], [42°43'32.58”N; 11°42'22.98”E], [42°45'49.22”N; 11°58'41.90”E]. Leonina and Lucciola Bella [43° 2'4.85"N; 11°45'35.75"E] are two of the best sites for walking through the biancanas, while Chiusure - Monte Oliveto Maggiore (i.e., the ancient Accona) and Radicofani [42°55'8.14"N; 11°44'38.82"E] host the most impressive calancos.
- ^ a b Torri, Dino; Rossi, Mauro; Brogi, Francesco; Marignani, Michela; Bacaro, Giovanni; Santi, Elisa; Tordoni, Enrico; Amici, Valerio; Maccherini, Simona (2018), "Badlands and the Dynamics of Human History, Land Use, and Vegetation Through Centuries", Badlands Dynamics in a Context of Global Change, Elsevier, pp. 111–153, doi:10.1016/b978-0-12-813054-4.00004-6, ISBN 978-0-12-813054-4
- ^ Marignani, Michela; Rocchini, Duccio; Torri, Dino; Chiarucci, Alessandro; Maccherini, Simona (January 2008). "Planning restoration in a cultural landscape in Italy using an object-based approach and historical analysis". Landscape and Urban Planning. 84 (1): 28–37. Bibcode:2008LUrbP..84...28M. doi:10.1016/j.landurbplan.2007.06.005.
- ^ Maccherini, S.; Marignani, M.; Gioria, M.; Renzi, M.; Rocchini, D.; Santi, E.; Torri, D.; Tundo, J.; Honnay, O. (August 2011). "Determinants of plant community composition of remnant biancane badlands: a hierarchical approach to quantify species-environment relationships: Determinants of plant community composition of remnant biancane badlands". Applied Vegetation Science. 14 (3): 378–387. doi:10.1111/j.1654-109X.2011.01131.x.
- ^ Torri, D.; Santi, E.; Marignani, M.; Rossi, M.; Borselli, L.; Maccherini, S. (July 2013). "The recurring cycles of biancana badlands: Erosion, vegetation and human impact". CATENA. 106: 22–30. Bibcode:2013Caten.106...22T. doi:10.1016/j.catena.2012.07.001.