BES was established in 1997 as one of two urban Long Term Ecological Research Project sites funded by the National Science Foundation. Baltimore has a long history of social-ecological research, allowing BES scientists to connect ecological and physical sciences research with an already well-developed understanding of the social organization and processes in Baltimore. BES began with a watershed approach pioneered by the Hubbard Brook Experimental Forest and has expanded to include a range of biophysical and social variables measured across the entire Baltimore metropolitan area. Today, the BES Experimental Forest area includes Baltimore City, Baltimore County, and the surrounding Anne Arundel, Carroll, Harford, and Howard counties.
BES research examines environmental features like trees, waterways, and soils, built structures like roads, ports, houses, and industrial facilities, and social factors like the distribution of people, health, wealth, and crime. One primary area of research within BES is the effect of patchy urban infrastructure and development on fluxes of nutrients, energy, and water in upland, stream, and coastal regions of metropolitan Baltimore. Climate data, including air temperature, precipitation, relative humidity, wind speed, wind direction, solar radiation have been collected since 2000. Since 1999, stream temperature, water quality and quantity, and pathogens have been monitored, along with soil moisture and temperature, soil water chemistry, tree growth and mortality, and trace gas fluxes. Eddy flux measurements began in 2001. Air temperature is recorded continuously throughout the year at 5-minute intervals in suburban Baltimore (Cub Hill, Maryland).