Developing land-use alternatives to slash-and-burn agriculture in the tropical zones.
Clearing rainforest is responsible for about 25% of the increase in global warming resulting from the emission of greenhouse gases. Deforestation also results in a great loss of plant and animal genetic diversity as well as the destruction of soils and the creation of erosion problems. About 60% of the area deforested annually is the result of the use of slash-and-burn techniques for agricultural settlement. The most important reasons behind the use of this technology are social problems and inappropriate land-use and land-tenure policies. Whilst local farmers have through many generations evolved techniques to sustain their agricultural production, much of the unsustainable slash-and-burn agriculture is carried out by landless immigrant farmers, unschooled in the subtleties of fallowing and other techniques for mitigating soil depletion under shifting cultivation.
The Global Initiative for Alternatives to Slash-and-Burn is an integrated research and development initiative of a group of international research centres, programmes and international and regional non-governmental organizations, coordinated by the International Centre for Research in Agroforestry. The first phase of the programme is funded by the Global Environmental Facility. Activities are grouped into three broad categories: biophysical research; social-economic research and policy options; and enhancement of human resource capacity. Researchers will quantify the economic and social impact of slash-and-burn practices and their sustainable alternatives. Part of this work will identify the underlying causes of migration and the likely patterns of further movement into forests and marginal lands. It will provide factual information on the economic value associated with the conservation of natural resources and biodiversity and the costs to society associated with land degradation. Capacity-building activities will be closely linked to the research agenda and to the needs of national research and development partners, providing support in three main areas: strengthening human resource through workshops and short-term training; providing information and documentation services; improving communication. Eight benchmark research sites, encompassing the range of biophysical and socio-economic conditions in the humid tropics where slash-and-burn is important, are being established for work on developing sustainable alternatives to slash-and-burn. An example is in the humid tropics of Cameroon, where calliandra is planted in a hedgerow intercropping pattern then pruned severely to minimize competition with growing crops. The calliandra rapidly becomes an improved fallow when the fields are abandoned, providing an alternative to natural forest fallows in shifting cultivation systems. Under this system, a 2-year leucaena-gliricidia fallow near Yaounde has produced 40 tonnes per hectare of wood and subsequently 6.3 tonnes per hectare of maize – about twice the yields produced under continuous cropping.
The Brazilian government ended its ruinous subsidies to the cattle ranchers, and now requires that settlers keep 80 percent of their land forested. Brazil has also set aside about 20 percent of the forest as parks, protected areas and indigenous reserves.
A worthy programme to set aside indigenous areas in the Amazon is only half completed in Brazil. The job must be finished, so that 10 percent more of the rainforests would be protected. The country also needs to develop zoning laws for the forests and to adopt sustainable logging practices. More broadly, Brazil must abandon the view that rain forest is only a commodity to be exploited for private gain.