Summer streamflow in industrial tree plantations harvested on 40- to 50-year rotations was 50% lower than in century-old forests, data from the long-term Alsea Watershed Study in the Oregon Coast Range showed. The research, led by Oregon State University’s Catalina Segura, is an important step toward understanding how intensively managed plantations might influence water supplies originating in forests and downstream aquatic ecosystems, especially as the planet becomes warmer and drier.