干旱区生态环境知识资源中心

Woody species and cactuses are a common feature of vegetation and therefore widely distributed in the Mediterranean zone. They can provide a large variety of products and services including forage to livestock. In semi-arid and arid areas, they constitute an indispensable drought fodder due to their ability of drawing moisture and minerals from the deep soil and retaining their leaves during the dry period with high nutritive value, especially crude protein and minerals. In addition, they can withstand environmental oscillations. Productivity varies widely among species and provenances as well as palatability. The latter, however, does not always relate with their chemical composition and digestibility perhaps because of the presence in most species of antiquality substances such as tannin and lignin indicating that the feeding value of woody forage plants is a complex problem. Selection of the most productive and nutritious species or cultivars and establishing them in the form of plantations for meeting the animal needs during the critical dry period can mitigate the problem of climatic uncertainty and ensure sustainable production systems. Such a strategic use of woody forage plants, however, should be employed after taking into account the other feed resources available, the grazing and pastoral systems practised and the socio-economic conditions involved in each particular region of the Mediterranean zone.