River flow response to deforestation: Contrasting results from different models

Forests are under pressure globally. How deforestation affects river flow is essential for water security in many regions. Here we conduct a meta-analysis of studies investigating this question in large basins of South America and show that different modeling approaches lead to opposite conclusions about deforestation effects on river flow. A widely used approach has been to use surface models while assuming that deforestation occurs only within the basin and does not affect precipitation. Alternative approaches consider that deforestation affects precipitation and is not necessarily bounded by the catchment area. While surface models generally indicate that deforestation will increase river flow in South American large basins, including deforestation effects on precipitation leads in most cases to the opposite conclusion.