Statistical confirmation of indirect land use change in the Brazilian Amazon

           One environmental impact that has raised serious concerns is loss of Amazonian forest through indirect land use change (ILUC), whereby mechanized agriculture encroaches on existing pastures, displacing them to the frontier. This phenomenon has been hypothesized by many researchers and projected on the basis of simulation for the Amazonian forests of Brazil. It has not yet been measured statistically, owing to conceptual difficulties in linking distal land cover drivers to the point of impact.
           Global demands for food and biofuel are expected to soar in coming decades . To meet these demands, new land will need to be brought into production. Brazil, with its abundant land resource, will no doubt continue to play an important role as a global supplier of agricultural commodities . Although conversions of forest to mechanized agriculture have been observed, pasture expansion remains by far the primary direct cause of Amazonian deforestation. Recent research suggests, however, that mechanized agriculture may exert a significant indirect effect, by the displacement of old pastures, and their recovery on the forest frontier. The present letter takes this displacement mechanism as ILUC, for the purposes of its analysis.
         

           In general, statistical explanations of land cover change have defined explanatory and dependent variables for a single location, possible with a set of nearby neighborhoods, a method that does not capture the effect of potentially distant influences. The approach in this letter overcomes the problem of distal spatial effects by using GIS to associate locations in the forest frontier where deforestation is occurring with ‘distant’ neighbors in the settled agricultural parts of Amazonia. The statistical models implemented possess a sufficiently general form that they can be implemented wherever ILUC is of interest to policy makers.
            The statistical models indicate that deforestation in the forest frontiers of the basin is strongly related to soy expansion in its settled agricultural areas, to the south and east.


Source: Arima, E. Y., Richards, P., Walker, R., & Caldas, M. M. (2011). Statistical confirmation of indirect land use change in the Brazilian Amazon.Environmental Research Letters, 6(2), 024010.