UC Davis

On December 13, 2004, the Zero Deforestation Law made deforestation illegal in Eastern Paraguay. Deforestation did not stop, however the law may have decreased deforestation. Most deforestation in this region is conducted to clear land for agriculture. In this dissertation, I conduct three analyses to investigate patterns of deforestation in Eastern Paraguay and the impact of this law on aggregate deforestation, predictors of deforestation, and post-deforestation agricultural land uses.

The first analysis investigates drivers of deforestation in Eastern Paraguay before the Zero Deforestation Law. I use satellite-derived deforestation data in a linear probability model to investigate how physical and anthropological land characteristics are correlated with forest loss between 2001 and 2004. I find that physical land characteristics including slope, elevation, soil group, and ecoregion were useful for predicting deforestation. Only some anthropological land characteristics predicted deforestation. Distances to towns or roads were not correlated with deforestation. Proximity to patchy forest cover, such as in areas of existing agricultural clearings, was correlated with more deforestation.

The second analysis investigates whether deforestation fell after the Zero Deforestation Law was implemented, and whether the relationship between land characteristics and deforestation changed. I use a linear probability model on a panel dataset of deforestation and land characteristics. My results show that deforestation fell by around a quarter after implementation. In addition, the predictive power of some drivers of deforestation weakened. One relationship reversed. Pre-policy, deforestation was more likely with less tree cover nearby, while post-policy, deforestation was more common near more densely forested areas, possibly indicating a desire to hide. My results cannot be explained by other events that took place during this time, and they provide strong evidence that the Zero Deforestation Law successfully lowered deforestation in Eastern Paraguay.

The third analysis investigates how these decreases in deforestation post-policy were distributed across small-scale subsistence-oriented agriculture, large-scale commodity-oriented agriculture, and large-scale cattle ranches. Data does not exist on post-deforestation agricultural land use, so I generate my own data using a three-step process. First, I manually identify the post-deforestation land use for randomly sampled deforested locations in Eastern Paraguay. Second, I use these observations to train random forest models that predict post-deforestation land use from physical and anthropological land characteristics. Third, I use these models to generate land use predictions for all pixels deforested in Eastern Paraguay within four years before or after the Zero Deforestation Law came into effect. I find that the decrease in deforestation after implementation can mostly be attributed to a decrease in deforestation for large-scale agriculture. Clearing for large-scale agriculture fell by over 60%, from 34 thousand hectares annually on average before the policy to 12 thousand hectares annually on average after the policy. This was due to a composition effect, under which different locations were deforested after the policy was implemented than before, and a land use effect, under which the same deforested locations were used for different agricultural classes in the pre- and post-policy periods. Levels of deforestation for rangeland and small-scale agriculture remained relatively steady between the pre- and post-policy periods.