The Accona Desert refers to a hilly area in the

Siena Siena ( , ; traditionally spelled Sienna in English; ) is a city in Tuscany, in central Italy, and the capital of the province of Siena. It is the twelfth most populated city in the region by number of inhabitants, with a population of 52,991 ...

province of

Italy Italy, officially the Italian Republic, is a country in Southern Europe, Southern and Western Europe, Western Europe. It consists of Italian Peninsula, a peninsula that extends into the Mediterranean Sea, with the Alps on its northern land b ...

, within the municipality of

Asciano Asciano () is a ''comune'' and hill town in the province of Siena in the Italy, 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. ...

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 divides Earth climates into five main climate groups, with each group being divided based on patterns of seasonal precipitation and temperature. The five main groups are ''A'' (tropical), ''B'' (arid), ''C'' (te ...

). 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, ...

can be found in the area of the

Crete Senesi The Crete Senesi refers to an area of the Italy, 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, Rapola ...

, 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 ...

areas of

Tuscany Tuscany ( ; ) is a Regions of Italy, region in central Italy with an area of about and a population of 3,660,834 inhabitants as of 2025. The capital city is Florence. Tuscany is known for its landscapes, history, artistic legacy, and its in ...

: ''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. Ravines are typically classified as larger in scale than gullies, although smaller than valleys. Ravines may also be called a cleuch, dell, ...

). 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 Basilicata (, ; ), also known by its ancient name Lucania (, , ), is an administrative region in Southern Italy, bordering on Campania to the west, Apulia to the north and east, and Calabria to the south. It has two coastlines: a 30-kilometr ...

and in

Calabria Calabria is a Regions of Italy, region in Southern Italy. It is a peninsula bordered by the region Basilicata to the north, the Ionian Sea to the east, the Strait of Messina to the southwest, which separates it from Sicily, and the Tyrrhenian S ...

. The calanco landscape is common all along the Apennines and in many parts of the

Alps The Alps () are some of the highest and most extensive mountain ranges in Europe, stretching approximately across eight Alpine countries (from west to east): Monaco, France, Switzerland, Italy, Liechtenstein, Germany, Austria and Slovenia. ...

. 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 (: sheep) or domestic sheep (''Ovis aries'') are a domesticated, ruminant mammal 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 d ...

goat The goat or domestic goat (''Capra hircus'') is a species of Caprinae, goat-antelope that is mostly 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 ...

s, and

cattle Cattle (''Bos taurus'') are large, domesticated, bovid ungulates widely kept as livestock. They are prominent modern members of the subfamily Bovinae and the most widespread species of the genus '' Bos''. Mature female cattle are calle ...

. Both practices were abandoned in the 1990s to favor measures to preserve biodiversity and geo forms under the EU

Natura 2000 Natura 2000 is a network of nature protection areas in the territory of the European Union. It is made up of Special Areas of Conservation and Special Protection Areas designated under the Habitats Directive and the Birds Directive, respectiv ...

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 Surface runoff, water flow or wind) that removes soil, Rock (geology), rock, or dissolved material from one location on the Earth's crust#Crust, Earth's crust and then sediment transport, tran ...

/deposition processes,

biodiversity Biodiversity is the variability of life, life on Earth. It can be measured on various levels. There is for example genetic variability, species diversity, ecosystem diversity and Phylogenetics, phylogenetic diversity. Diversity is not distribut ...

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 (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: Abbadia ...

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 *Etruscan civilization (1st millennium BC) and related things: **Etruscan language ** Etruscan architecture **Etruscan art **Etruscan cities **Etruscan coins **Etruscan history **Etruscan myt ...

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 Roman civilization *Epistle to the Romans, shortened to Romans, a letter w ...

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 Animal husbandry is the branch of agriculture concerned with animals that are raised for meat, animal fiber, fibre, milk, or other products. It includes day-to-day care, management, production, nutrition, selective breeding, and the raising ...

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 The Black Death was a bubonic plague pandemic that occurred in Europe from 1346 to 1353. It was one of the list of epidemics, most fatal pandemics in human history; as many as people perished, perhaps 50% of Europe's 14th century population. ...

, (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 Chiusure is a village in Tuscany, central Italy, administratively a frazione of the comune of Asciano, province of Siena. At the time of the 2001 census its population was 115.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 of Monte Oliveto Maggiore (1320-1344) on the site of the Tolomei's Accona ''podere'' (farm).

Pope Pius II Pope Pius II (, ), born Enea Silvio Bartolomeo Piccolomini (; 18 October 1405 – 14 August 1464), was head of the Catholic Church and ruler of the Papal States from 19 August 1458 to his death in 1464. Aeneas Silvius was an author, diplomat, ...

(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'' ("European olive"), is a species of subtropical evergreen tree in the family Oleaceae. Originating in Asia Minor, it is abundant throughout the Mediterranean Basin, with wild subspecies in Africa ...

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, the te ...

almond The almond (''Prunus amygdalus'', Synonym (taxonomy)#Botany, syn. ''Prunus dulcis'') is a species of tree from the genus ''Prunus''. Along with the peach, it is classified in the subgenus ''Amygdalus'', distinguished from the other subgenera ...

vine A vine 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 themselves, for instance, when used in wicker work.Jackson; Benjamin; Da ...

orchard An orchard is an intentional plantation of trees or shrubs that is maintained for food production. Orchards comprise fruit tree, fruit- or nut (fruit), nut-producing trees that are generally grown for commercial production. Orchards are also so ...

s, small cypress woods, oaks and

juniper Junipers are coniferous trees and shrubs in the genus ''Juniperus'' ( ) of the cypress family Cupressaceae. Depending on the taxonomy, between 50 and 67 species of junipers are widely distributed throughout the Northern Hemisphere as far south ...

s. 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&n ...

silty-clay over consolidated marine deposits rich in

sodium Sodium is a chemical element; it has Symbol (chemistry), symbol Na (from Neo-Latin ) and atomic number 11. It is a soft, silvery-white, highly reactive metal. Sodium is an alkali metal, being in group 1 element, group 1 of the peri ...

. 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 Overgrazing occurs when plants are exposed to intensive grazing for extended periods of time, or without sufficient recovery periods. It can be caused by either livestock in poorly managed agricultural applications, game reserves, or nature ...

) 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, is a mixture of organic matter, minerals, gases, water, and organisms that together support the life of plants and soil organisms. Some scientific definitions distinguish dirt from ''soil'' by re ...

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 Subsoil is the layer of soil under the topsoil on the surface of the ground. Like topsoil, it is composed of a variable mixture of small particles such as sand, silt and clay, but with a much lower percentage of organic matter and humus. The su ...

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 a period of 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, ...

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 river situated in the provinces of Grosseto and Siena, 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 twistin ...

, 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

bulldozer A bulldozer or dozer (also called a crawler) is a large tractor equipped with a metal #Blade, blade at the front for pushing material (soil, sand, snow, rubble, or rock) during construction work. It travels most commonly on continuous tracks, ...

s 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 Commission. It implements a system of agricultural subsidies and other programmes. It was introduced in 1962 and has since then undergone several changes to reduce ...

. Thus it can be said that damage mainly due to an epidemic (Black Death) was eventually solved by the EU-CAP of 1960-2000. 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 Catholic priest and the founder of the Congregation of the Blessed Virgin of Monte Oliveto. In the Roman Martyrology he is commemorated on 20 August, but in the Benedictine calen ...

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.

References

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

History

Anthropic influence

See also

References