The role of cacti (Opuntiaspp.) in erosion control, land reclamation, rehabilitation and agricultural development in the Mediterranean Basin

Cacti, particularlyOpuntia ficus-indica(= O. ficus-barbarica), were introduced to Spain at the end of the 15th century and from there spread over the whole Mediterranean Basin. They have been used for almost 500 years as a fruit crop, a defensive hedge, a support for cochineal production of dye (carminic acid) and, more recently, as a fodder crop and as a standing buffer feed for drought periods; they can also play a key role in erosion control and land rehabilitation, particularly in arid and semi-arid zones, and as a shelter, refuge and feed resource for wildlife (birds and mammals alike). This article analyses the ecological requirements of cacti and particularly of the common and most utilized spineless type,Opuntia ficus-indicaformainermis, its drought-tolerance, food and feed value for humans, herbivores and fructivores and its potential for land rehabilitation, cheap and easy erosion control and the rational use of marginal land. Cactus plantations and hedges probably cover about 1,000,000 ha in the Basin (includingO. ficus-indicaformaamyclaea), particularly in the Mediterranean islands and North Africa; but, unlike in other subtropical zones, cacti have never become an invasive pest in the Basin. The spineless cacti never become invasive pests anyway, as they are grazed out, unless totally protected from herbivores, either naturally (cliffs) or artificially (fences).