摘要：Expansion of global demand for soy products and biofuel poses threats to food security and
the environment. 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. The present article overcomes this impasse with a spatial
regression model capable of linking the expansion of mechanized agriculture in
settled agricultural areas to pasture conversions on distant, forest frontiers. In an
application for a recent period (2003–2008), the model demonstrates that ILUC is
significant and of considerable magnitude. Specifically, a 10% reduction of soy in old
pasture areas would have decreased deforestation by as much as 40% in heavily
forested counties of the Brazilian Amazon. Evidently, the voluntary moratorium
on primary forest conversions by Brazilian soy farmers has failed to stop the
deforestation effects of expanding soy production. Thus, environmental policy in Brazil
must pay attention to ILUC, which can complicate efforts to achieve its REDD
targets.
