Evaluating the Impacts of Land-Use Change and Climate Change on Agriculture and EcosystemServices in Brazil

Background

The expansion of Brazil’s agricultural production has come at the expense of the supply of ecosystem services. One of the key services affected is the rainfall maintenance service of forests. Forests regulate rainfall through evapotranspiration; converting forests to croplands reduces rainfall, also on croplands. Whereas information on rainfall effects is still scarce, there is ample evidence for effects on biodiversity and carbon retention. Connecting these insights to policy and decision making is challenging. This study aims to expand the current understanding of a key ecosystem service, the rainfall regulation service of forests, and to assess how knowledge of this and other important ecosystem services can be better used in policy and decision making. The focus of the study is on the forest-agricultural frontier within the Amazon and Cerrado biomes, where most of the agricultural expansion has taken place in Brazil. First, I will enhance an existing machine learning model to analyze how deforestation affected rainfall and subsequently crop production in the last decade. Second, we will add the effect of climate change to assess future impacts of deforestation on agriculture and ecosystem services. Third, we will employ ecosystem accounting to analyze ecosystem services in a farm level. Finally, we will discuss how improvements of environmental farm management, integrated with farm-level ecosystem accounting, can be incorporated into both public and private policies.

Project description

The focus of the study is on the forest-agricultural frontier within the Amazon and Cerrado biomes, where most of the agricultural expansion has taken place in Brazil. First, I will enhance an existing machine learning model to analyze how deforestation affected rainfall and subsequently crop production in the last decade. Second, we will add the effect of climate change to assess future impacts of deforestation on agriculture and ecosystem services. Third, we will employ ecosystem accounting to analyze ecosystem services in a farm level. Finally, we will discuss how improvements of environmental farm management, integrated with farm-level ecosystem accounting, can be incorporated into both public and private policies.

Results

The first paper of this research project examined how loss in forest cover has impacted agricultural yields through change in rainfall. We assessed yield changes within the soybean-maize double cropping system, the country's most relevant agricultural system, in five states within the Amazon and Cerrado biomes. Findings revealed that soybean and maize yields would have been respectively 6.6 % and 9.9% higher per year in the last decade if rainfall patterns hadn't been altered by deforestation from 1982 onwards. Although agricultural efficiency improved between 2011 and 2020, it was insufficient to offset the negative effect of altered rainfall on yields. Our paper reveals the link between deforestation and crop yields, emphasizing the need to preserve forest cover for agricultural resilience and food security. It reinforces the critical role of forests in regulating the water cycle, particularly in the face of climate change-induced warmer and drier conditions that can impact agricultural production and other human activities.

Publications

Deforestation-induced
changes in rainfall decrease soybean-maize yields in Brazil — Research@WUR