Accona Desert

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.

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.

Archaeological maps of the Siena province show that the Crete Senesi area was inhabited in Etruscan and Roman times.

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.

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.

Only after the Restoration did the Olivetan Benedictines recover the Monastery of Monte Oliveto and slowly resume their role as local leaders.

Deep, narrow cracks (joints;[14]) cut the deposits to about 10m from the surface, favoring localized water infiltration and the excavation of subterranean tunnels.

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.

[18] At the same time foreign armies (e.g. Henry VII's, mercenaries) passing through the Sienese territory interfered with normal activities in the countryside.

[19] The climate was characterized by droughts and extreme events[19][20] 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.

Later, between 1830 and 1850 when the badlands were at their maximum, the label "Accona desert" was adopted by scholars and learned persons[23][24] to convey the feeling of desolation felt when in the midst of the biancana fields or the calanco gullies.