Sustainable management of the Gran Chaco of South America: Ecological promise and economic constraints

The vast plain known as the Gran Chaco is a natural region of more than 1·3 million square kilometres, the second largest natural biome in South America, with only the Amazon region being larger. It extends over parts of Argentina, Bolivia, Paraguay and, marginally, Brazil. The original landscape of the region was mostly a park land with patches of hardwoods intermingled with grasslands. Increasing human encroachment, largely by poor campesinos, with associated overgrazing, excessive timber harvesting, charcoal production and over-exploitation of wildlife, is transforming the region into a dense and unproductive shrub land and is contributing to increasing rural poverty. A management system for the sustainable use of the Chaco has been developed based on a multiple-species ranching system that includes beef, timber, charcoal and wildlife production. An evaluation of the management system finds that it is capable of protecting and enhancing the resource base, while providing higher economic returns in a sustainable manner. However, high initial costs, as well as a divergence between the «best» interests of campesinos and society, jeopardize the feasibility of the managed system.