Forests play a key part in the water cycle, so both planting and removing forests can affect streamflow. In a recent Article1, Evaristo and McDonnell used a gradient-boosted-tree model to conclude that streamflow response to forest removal is predominantly controlled by the potential water storage in the landscape, and that removing the world’s forests would contribute an additional 34,098 km3 yr−1 to streamflow worldwide, nearly doubling global river flow. Here we report several problems with Evaristo and McDonnell’s1 database, their model, and the extrapolation of their results to the continental and global scale. The main results of the paper1 remain unsubstantiated, because they rely on a database with multiple errors and a model that fails validation tests.@en

A new study finds that when more precipitation falls as rain instead of snow, stream flows in drainage basins decline. This could complicate matters for areas that need snowmelt for water.@en