Invasive Species Compendium

Detailed coverage of invasive species threatening livelihoods and the environment worldwide

Abstract

The increasing barrenness of the Sahelian zone in Chad. The situation after 10 years of protective measures.

Abstract

Outlines the climate, geology, soils and vegetation of the Sahelian zone in Chad (i.e. the dry savanna to semi-desert belt immediately S. of the Sahara), and discusses the long-term deterioration in the soil and vegetation, confirmed by past records and largely attributable to man and livestock. An illustrated account is given of the remarkable improvement in both the woody and herbaceous vegetation evident in a 305-ha block near Abeche (dominated by Acacia raddiana, A. mellifera and other Acacias) from which man and stock have been excluded by fencing for 10 years. The beneficial effect of protection is particularly noticeable among fast-growing browse species (Ziziphus mauritiana, Dichrostachys glomerata and Capparis decidua) and species that yield various useful materials (Acacia scorpioides-construction wood, bark and pods; A. seyal-firewood and charcoal; Balanites aegyptiaca-thorn fencing for cattle kraals; and Commiphora africana-saddles for donkeys). The results (tabulated) of trials of several Eucalypts and other introduced species, except those of Azadirachta indica, are not promising. KEYWORDS: Abies raddiana \ Abies scorpioides \ Abies seyal \ Balanites aegyptiaca \ Capparis decidua \ Commiphora africana \ Dichrostachys glomerata \ vegetation types \ general plant communities \ studies \ vegetation types \ general relation \ biotic factors fauna, grazing, insects \ vegetation types \ trop