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Cacti, particularly Opuntia ficus-indica, 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, and 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 and and semi-arid zones, and as a shelter, refuge and feed resource for wildlife (birds and mammals alike). They are particularly adapted to and lands that are unfit for traditional crops for reasons of topography, soils or aridity. They are unfit, however, for areas with cold winters and saline land.

The ecology and bioclimatic requirements of Opuntia ficus-indica and other occasionally fodder crop species are analysed, particularly their drought and heat tolerance, their cold tolerance. Their feed value is assessed and recent experiments on intake and digestibility reviewed. They may also constitute a shelter and feed resource for wildlife: fructivores and herbivores. Easy agronomic methods are described to considerably increase the nitrogen content of the pads, thus raising them to the standard value of classical fodder crops. Their potential for degraded land rehabilitation is explained, as inexpensive and easy erosion control tool for the rational use of marginal land. Cactus plantations and hedges probably cover about. one million hectares in the Basin (including Opuntia ficus-indica fa. amyclaea (the spiny form), particularly in the Mediterranean islands and North Africa; but, unlike in other subtropical zones, cacti never became an invasive pest in the Basin. Spineless cacti never become invasive pests anyway, as they are grazed out, unless totally protected from herbivores, either naturally (cliffs) or artificially (fences). Contrary to other subtropical zones, Mediterranean Basin cacti have not been subjected to heavy parasite infestations neither, from the cactus scale (Dactylopius) nor from the cactus moth (Cactoblastis), that in other areas decimated the populations, either deliberately or inadvertently.