Artemi Cerdà
University of Valencia, Valencia, Spain
Antonio Jordán
University of Seville, Sevilla, Spain
In the Mediterranean, soil erosion causes rock fragments to surface easily, so that stony soils are very common. The stones on the ground are collected and used for the construction fences (dry stone walls) and separating properties by farmers.
In most cases, fences are built without any mortar to keep stones together (occasionally, sand is used), and fences are stable simply because of the correct arrangement of the stones, which are positioned to maximize the contact surface and gravity.

Grazing and stone landscape (2), by Artemi Cerdà. Click to see the original picture at Imaggeo. by Artemi Cerdà,
Often, drystone walls are used as a tool against soil erosion. In the pictures below, stone walls were built several hundred years ago in olive-cropped soils in S’Arxiduc (Mallorca, Spain). These traditional structures have been maintained and restored periodically to date by farmers, and are part of the Mediterranean landscape.

Drystone walls for soil conservation, by Antonio Jordán. Click to see the original picture at Imaggeo.

Drystone walls in Mallorca (Spain) against soil erosion. Lorena M. Zavala (University of Seville) works as scale. Credit: Antonio Jordán. Click to see the original picture at Imaggeo.
This post was also published simultaneously in G-Soil.