Two Decades of Research in Baltimore (IMAGE) USDA Forest Service - Northern Research Station Caption Two decades of USDA Forest Service research in Baltimore contributed to "The Baltimore School of Urban Ecology," the first new school of urban ecology to emerge in more than 90 years. Credit USDA Forest Service Usage Restrictions None License Licensed content Disclaimer: AAAS and EurekAlert! are not responsible for the accuracy of news releases posted to EurekAlert! by contributing institutions or for the use of any information through the EurekAlert system.