Our long-term results are relevant to land areas that are in pasture and those that have reverted back to forests. We found that within a deciduous forest, species identity matters in terms of how much precipitation leaves the watershed as evapotranspiration versus water yield. We demonstrate that a shift in tree species composition from species with ring-porous xylem to species with diffuse-porous xylem can increase water use, and in turn, produce a long-term reduction in water yield.