Accona desert refers to a hilly area in the

Siena Siena ( , ; lat, Sena Iulia) is a city in Tuscany, Italy. It is the capital of the province of Siena. The city is historically linked to commercial and banking activities, having been a major banking center until the 13th and 14th centur ...

province of

Italy Italy ( it, Italia ), officially the Italian Republic, ) or the Republic of Italy, is a country in Southern Europe. It is located in the middle of the Mediterranean Sea, and its territory largely coincides with the homonymous geographical ...

, within the municipality of

Asciano Asciano () is a ''comune'' and hill town in the province of Siena in the Italian region Tuscany. It is located at the centre of the Crete senesi between the river Ombrone and the torrent Copra, some southeast of the town of Siena by rail. Hist ...

3°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 The Köppen climate classification is one of the most widely used climate classification systems. It was first published by German-Russian climatologist Wladimir Köppen (1846–1940) in 1884, with several later modifications by Köppen, notabl ...

). A real desert has never existed here. However, there have been temporarily severely eroded areas, more properly called "badlands". LeoninaBiancanas

Two main types of

badlands Badlands are a type of dry terrain where softer sedimentary rocks and clay-rich soils have been extensively eroded."Badlands" in ''Chambers's Encyclopædia''. London: George Newnes, 1961, Vol. 2, p. 47. They are characterized by steep slopes, m ...

can be found in the area of the

Crete Senesi The Crete Senesi refers to an area of the Italian region of Tuscany immediately to the south of Siena. It consists of a range of hills and woods among villages and includes the ''comuni'' of Asciano, Buonconvento, Monteroni d'Arbia, Rapolano Ter ...

, the Valdorcia, and the

Volterra Volterra (; Latin: ''Volaterrae'') is a walled mountaintop town in the Tuscany region of Italy. Its history dates from before the 8th century BC and it has substantial structures from the Etruscan, Roman, and Medieval periods. History Volt ...

areas of

Tuscany it, Toscano (man) it, Toscana (woman) , population_note = , population_blank1_title = , population_blank1 = , demographics_type1 = Citizenship , demographics1_footnotes = , demographics1_title1 = Italian , demogra ...

: ''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 A ravine is a landform that is narrower than a canyon and is often the product of streambank erosion.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 The Alps () ; german: Alpen ; it, Alpi ; rm, Alps ; sl, Alpe . are the highest and most extensive mountain range system that lies entirely in Europe, stretching approximately across seven Alpine countries (from west to east): France, Swi ...

. 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 Sheep or domestic sheep (''Ovis aries'') are domesticated, ruminant mammals typically kept as livestock. Although the term ''sheep'' can apply to other species in the genus '' Ovis'', in everyday usage it almost always refers to domesticated ...

goat The goat or domestic goat (''Capra hircus'') is a domesticated species of goat-antelope typically kept as livestock. It was domesticated from the wild goat (''C. aegagrus'') of Southwest Asia and Eastern Europe. The goat is a member of the a ...

s, and

cattle Cattle (''Bos taurus'') are large, domesticated, cloven-hooved, herbivores. They are a prominent modern member of the subfamily Bovinae and the most widespread species of the genus ''Bos''. Adult females are referred to as cows and adult ma ...

. 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 Erosion is the action of surface processes (such as water flow or wind) that removes soil, rock, or dissolved material from one location on the Earth's crust, and then transports it to another location where it is deposited. Erosion is dis ...

/deposition processes,

biodiversity Biodiversity or biological diversity is the variety and variability of life on Earth. Biodiversity is a measure of variation at the genetic (''genetic variability''), species (''species diversity''), and ecosystem (''ecosystem diversity'') l ...

is also threatened and the biancana landscape is forecast to disappear entirely within 20-40 years as brush cover expands. Spots where the traditional forms can still be observed are scattered in the

and the Valdorcia, included within the quadrangle of vertices 3°16'10.58"N ; 11°15'59.30”E 3°18'28.68”N; 11°39'4.92”E 2°43'32.58”N; 11°42'22.98”E 2°45'49.22”N; 11°58'41.90”E Leonina and Lucciola Bella 3° 2'4.85"N; 11°45'35.75"Eare two of the best sites for walking through the biancanas, while Chiusure -

Monte Oliveto Maggiore The Abbey of Monte Oliveto Maggiore is a large Benedictine monastery in the Italian region of Tuscany, 10 km south of Asciano. Its buildings, which are mostly of red brick, are conspicuous against the grey clayey and sandy soil—the '' Cret ...

(i.e., the ancient Accona) and

Radicofani Radicofani () is a '' comune'' in the Province of Siena in the Italian region Tuscany, located in the natural park of Val d'Orcia about southeast of Florence and about southeast of Siena. Radicofani borders the following municipalities: A ...

2°55'8.14"N; 11°44'38.82"Ehost the most impressive calancos. LeoninaBiancanaCloseView

History

Archaeological maps of the Siena province show that the Crete Senesi area was inhabited in

Etruscan __NOTOC__ Etruscan may refer to: Ancient civilization *The Etruscan language, an extinct language in ancient Italy *Something derived from or related to the Etruscan civilization **Etruscan architecture **Etruscan art **Etruscan cities ** Etrusca ...

and

Roman Roman or Romans most often refers to: *Rome, the capital city of Italy *Ancient Rome, Roman civilization from 8th century BC to 5th century AD *Roman people, the people of ancient Rome *'' Epistle to the Romans'', shortened to ''Romans'', a lette ...

times. Almost every slope contains remnants of that period. The periods of the Barbarian invasions, the Gothic wars, and the Justinian plague caused a demographic decline which reduced the anthropic impact on the environment and favored the natural reforestation of the area. Nevertheless, in the seventh century Asciano was already a ''Curtis Regia.'' It was a village with a territory where agriculture and animal husbandry coexisted with hunting reserves used by the Lombard lords. In the 10th century, documents show Leonina, too, as ''Curtis''. Other rudimentary documentation testifies to the existence of a settlement in Leonina. At the time of the Black Death, (1348 with several returns of the plague in the following 60-70 years ) Leonina's population halved from more than 150-160 to about 60 at the beginning of 1400. This fate was common to Siena, Asciano and the whole territory of the Sienese Republic: Siena's population fell from about 50,000 before the Black Death to 14-16,000 in 1400-1450 (Ginatempo, 1990) and returned to pre-plague levels only at the end of the 20th century. Asciano, with its surroundings, was a major town in the Sienese territory for a long time and contributed to the Republic's economy in a substantial way, gaining Sienese citizenship in 1369. A few kilometers south of Asciano, the small town of Chiusure grew around the seventh century church of Sant'Angelo in Luco, even though the hill on which the village is located would have been threatened by the approach of the heads of large (and deep) gully systems retreating upslope. It had an economy mainly based on agriculture and animal husbandry. Chiusure's importance is due mainly to its proximity to Accona about 1 km away. The members of three leading Sienese families (Tolomei, Patrizi, and Piccolomini) founded in 1313 what became the

Benedictine monastery , image = Medalla San Benito.PNG , caption = Design on the obverse side of the Saint Benedict Medal , abbreviation = OSB , formation = , motto = (English: 'Pray and Work') , found ...

of Monte Oliveto Maggiore (1320-1344) on the site of the Tolomei's Accona ''podere'' (farm).

Pope Pius II Pope Pius II ( la, Pius PP. II, it, Pio II), born Enea Silvio Bartolomeo Piccolomini ( la, Aeneas Silvius Bartholomeus, links=no; 18 October 1405 – 14 August 1464), was head of the Catholic Church and ruler of the Papal States from 19 August ...

(Enea Piccolomini) visited the monastery during his papacy (1458-1464) and described the area as rich in

olive trees The olive, botanical name ''Olea europaea'', meaning 'European olive' in Latin, is a species of small tree or shrub in the family Oleaceae, found traditionally in the Mediterranean Basin. When in shrub form, it is known as ''Olea europaea'' 'M ...

fruit tree A fruit tree is a tree which bears fruit that is consumed or used by animals and humans — all trees that are flowering plants produce fruit, which are the ripened ovaries of flowers containing one or more seeds. In horticultural usage, t ...

s, almonds,

vine A vine (Latin ''vīnea'' "grapevine", "vineyard", from ''vīnum'' "wine") is any plant with a growth habit of trailing or scandent (that is, climbing) stems, lianas or runners. The word ''vine'' can also refer to such stems or runners themsel ...

orchard An orchard is an intentional plantation of trees or shrubs that is maintained for food production. Orchards comprise fruit- or nut-producing trees which are generally grown for commercial production. Orchards are also sometimes a feature of ...

s, small cypress woods, oaks and junipers. Furthermore, Pius II added, there was water: a perennial spring, wells, tanks, and cisterns. From this time until 1796, the monastery played a leadership role in the spheres of economy and spirituality. The area has churches, monasteries, and farms. Then, under French rule from 1797 all the Church possessions were confiscated and sold. Only after the Restoration did the Olivetan Benedictines recover the Monastery of Monte Oliveto and slowly resume their role as local leaders.

Anthropic influence

The

lie on top of

Plio-Pleistocene The Plio-Pleistocene is an informally described geological pseudo-period, which begins about 5 million years ago (Mya) and, drawing forward, combines the time ranges of the formally defined Pliocene and Pleistocene epochs—marking from about 5&nb ...

silty-clay over consolidated marine deposits rich in

sodium Sodium is a chemical element with the symbol Na (from Latin ''natrium'') and atomic number 11. It is a soft, silvery-white, highly reactive metal. Sodium is an alkali metal, being in group 1 of the periodic table. Its only stable ...

. Deep, narrow cracks (joints;) cut the deposits to about 10m from the surface, favoring localized water infiltration and the excavation of subterranean tunnels. In natural, unstressed conditions, soils can develop as deep as 1.5 m, with removal of sodium by the leaching action of infiltration water. The present situation is characterized by the presence of eroded or poorly developed soils especially in the badlands. Intense animal activities (trampling, overgrazing) and anthropic activities (deforestation, tillage operations, exposure of bare soil surface to weather agents on excessively sloping grounds) favor surface soil erosion, causing small rivulets, rills and gullies. The rate of soil erosion varies from zero to 1–2 mm of soil removed yearly. If gullies are excavated by concentrating overland flow, erosion values in a field can attain 2–4 mm of soil loss in a single rain event. Excessive animal grazing facilitates gully erosion, soil slips and mass movements. Cropland management requires tillage (deep ploughing, seed bed preparation) and sometimes large earth movements. All these activities cause a net movement of soil from the upslope side of the field to the downslope side.

Soil Soil, also commonly referred to as earth or dirt Dirt is an unclean matter, especially when in contact with a person's clothes, skin, or possessions. In such cases, they are said to become dirty. Common types of dirt include: * Debri ...

in the upslope side of the field is lost at rates between 1 and 4 cm yearly. For medieval tilling techniques, the estimated erosion rate would have been around 2 cm/year. Considering an alternation of years with and without ploughing, 300 years would have been enough to expose the subsoil still rich in sodium. Sodium gives dispersive characteristics to the clay, making it very erodible, hence increasing the velocity of rain-induced erosion. The first half of the fourteenth century was characterized by social unrest due to the transformation from farmers who owned their land to large land holdings with the property subdivided into poderi. Each pderi was managed by a farmer (mezzadro) and his family living on the fields in a crop sharing system. At the same time foreign armies (e.g. Henry VII's, mercenaries) passing through the Sienese territory interfered with normal activities in the countryside. Hence, erosion and floods are testified in several documents, including t Lorenzetti's Buongoverno frescos (1340) that show biancanas while severe floods are reported. The climate was characterized by

drought A drought is defined as drier than normal conditions.Douville, H., K. Raghavan, J. Renwick, R.P. Allan, P.A. Arias, M. Barlow, R. Cerezo-Mota, A. Cherchi, T.Y. Gan, J. Gergis, D. Jiang, A. Khan, W. Pokam Mba, D. Rosenfeld, J. Tierney, an ...

s and extreme events that led to a shortage of food in Italy and necessitated imports from abroad. This forced Siena to invest a large part of its wealth in facing these difficulties, and divert funds from other priorities such as flood prevention. In the second half of the 14th century the abrupt and large demographic decrease due to the plagues resulted in the farming population of small owners and mezzadri needing to manage twice as much livestock and land per capita. With no resources for maintenance, the only use for a severely eroded field was animal grazing. Hence, the eroded fields became irrecoverable. The lack of personnel persisted for about two centuries during which the eroded areas expanded, reaching a maximum in the 19th century. This picture is substantially confirmed by soil denudation rates estimated using average erosion in the basin of the river

Ombrone The Ombrone (Latin: ''Umbro'') is a long river in Tuscany, central Italy. The Ombrone's source is at San Gusmè, near Castelnuovo Berardenga, on the south-eastern side of the Monti del Chianti. After a twisting route, it receives the waters of ...

, which drains the area, and on the denudation rates of the two largest biancanas of the Leonina site and the gully in between. Biancana badlands reclamation began at the end of the 19th century and ended during the second half of the 20th century when bulldozers removed almost all the biancanas and some of the smallest calancos, encouraged by EU subsidies then available under the

Common Agricultural Policy The Common Agricultural Policy (CAP) is the agricultural policy of the European Union. It implements a system of agricultural subsidies and other programmes. It was introduced in 1962 and has since then undergone several changes to reduce the ...

. Thus it can be said that damage mainly due to an epidemic (Black Death) was eventually solved by the EU-CAP of 1960-2000.

Accona Desert

The natural and social history of the Crete Senese does not leave much room, either temporal or spatial, for any physical desert. Nevertheless, there certainly were large areas that progressively became severely eroded and devoid of vegetation. The Accona podere when

Bernardo Tolomei Bernardo Tolomei (10 May 1272 – 20 August 1348) was an Italian Roman Catholic theologian and the founder of the Congregation of the Blessed Virgin of Monte Oliveto. In the Roman Martyrology he is commemorated on August 20, but in the Benedi ...

retired there in 1313 may have been in poor condition, certainly without any mezzadro. Hence, in all likelihood, the desert of Accona referred at first to the absence of farmers in Accona and/or the lack of strong spiritual leadership, a role that the Olivetans had filled. Later, between 1830 and 1850 when the badlands were at their maximum, the label "Accona desert" was adopted by scholars and learned persons to convey the feeling of desolation felt when in the midst of the biancana fields or the calanco

gullies A gully is a landform created by running water, mass movement, or commonly a combination of both eroding sharply into soil or other relatively erodible material, typically on a hillside or in river floodplains or terraces. Gullies resemble lar ...

References

{{DEFAULTSORT:AcconaDesert, the Black Death and soil erosion Deserts of Italy Geography of Tuscany Landscape Environmental history Badlands

History

Anthropic influence

Accona Desert

See also

References