REHABILITATION OF DEGRADED ECOSYSTEMS IN CENTRAL CHILE AND ITS RELEVANCE TO THE ARID NORTE-CHICO

An ecosystem rehabilitation project in the subhumid 7th Region of cent ral Chile is described, with a three-tiered research and development ( R & D) approach that addresses the structure and functioning of soils and vegetation and aims, in the long-term, at a fullscale transformati on of the region into a mosaic of agroforestry systems and nature ecos ystem reserves. The important role of native and carefully-screened ex otic nitrogen-fixing legumes in ''jumpstarting'' the rehabilitation pr ocess is underlined. We then suggest that a similar R gr D approach co uld be applied in the arid ''Norte Chico'' region of northern Chile as well. Apart from immediate interventions, emphasis is placed on revis ed management of land and water, flora! and fauna through the replacem ent of ''artificial negative selection'' by a strategy of ''positive s election''. Also noted are the numerous gaps in current knowledge and the grinding socio-economic realities that hinder any rapid realizatio n of our optimistic scenario.