Chomitz and Gray looked at Belize and formulated models to try to predict the effects of building roads, logging, mining, and agriculture on future levels of deforestation. The authors used land-use and economic models and GIS technology to determine potential threat of deforestation in different areas from human development. With this knowledge the authors worked to assess the trade-offs between development and environmental degradation of different actions. In this way the authors could determine the most productive and least damaging route of action. The authors hypothesize that impacts on the forest from road development will differ depending on the area and local conditions (such as proximity to towns and soil conditions). In some cases the clearing that takes place to build the roads are not the biggest concern, it is the door it opens for other people to come in and clear forest for subsistent (growing food to feed yourself) or commercial agriculture (Chomitz & Gray, 489).
Some studies have attempted to map out areas that are at risk for deforestation, but none have taken as many variables and models into consideration. For those reasons this study is unlike others before it. The authors concluded that both commercial and subsistent agriculture are more common closer to the roads and towns and more sparse deeper into the forest. This means that roads will lead to some level of deforestation around them due to the accessibility they provide. They also found that soil quality and properties have a large influence on the probability of that land being used for agriculture. It was originally believed that natives would plant on most any soil without regard to Nitrogen or soil fertility. This study, however, found that to be completely untrue. There is a distinct pattern of native subsistent agriculture in areas where the soil has high levels of Nitrogen, good levels of potassium, and a balanced pH. The authors also found that soil quality was more influential to the placement of subsistent agriculture and less important to commercial agriculture. Ultimately, the author’s concluded that distance from markets (towns/cities), land quality, and tenure have “strong interactive effects on the likelihood and type of cultivation” (Chomitz & Gray, 501).
Chomitz, K. M., & Gray, D. A. (1996). Roads, land use, and deforestation: a spatial model applied to Belize. The World Bank Economic Review, 10(3), 487-512.