Baltimore Cooperating Experimental Forest

The BES area includes Baltimore City, Baltimore County, and the counties of Ann Arundel, Carrol, Harford, Howard, and Montgomery. A primary study unit is the 17,150 ha Gwynns Falls Watershed. The Gwynns Falls watershed is a mix of land-use types including agricultural and forested lands, recently suburbanized areas, established suburbs, and dense urban areas having residential, commercial and open spaces.

Climate

The Baltimore metropolitan area has hot humid summers and cold winters with average annual air temperatures ranging from 14.5 °C in the city to 12.8 °C in the surrounding area. Precipitation is distributed evenly throughout the year and ranges from an annual average of 108 cm yr^-1 in Baltimore to 104 cm yr^{- 1} in the surrounding metropolitan area. Maximum evapotranspiration occurs during July, and groundwater reservoirs are recharged primarily between mid-September and March. The greatest rainfall intensities occur in the summer and early fall; precipitation from this period is about 10 percent higher than during the remaining three seasons of the year. The proximity of large bodies of water and the inflow of southerly winds contribute to relatively high humidity during much of the year.

Vegetation

The Baltimore metropolitan area was previously dominated by hardwood deciduous forests with smaller areas of riparian and wetland vegetation. After European colonization and before the development of the city, the forested areas were transformed to agricultural uses. Forest cover, mostly outside the city, is dominated by chestnut oak, yellow-poplar; box elder, green ash sycamore and silver maple are found in riparian areas. Overall, Baltimore City has a canopy cover of approximately 28 percent with the majority of tree stems occurring in remnant forest patches, vacant land, and residential areas that are dominated by ash species, American elm, American beech, black cherry, black locust, and tree-of-heaven.

Soil and Surface Geology

The Gwynns Falls watershed lies in two physiographic provinces, the Piedmont Plateau to the north and the Atlantic Coastal Plain to the south, which are separated by the Fall Zone. The topography varies from “gently sloping” to “hilly” with locally steep slopes and bedrock outcroppings within drainage corridors. The Piedmont Plateau in the watershed is underlain by mafic, and ultramafic rock types. The Coastal Plain in the watershed is underlain by much younger, poorly consolidated sediments. Soils in the Coastal Plain are very deep, somewhat excessively drained and well-drained upland soils that are underlain by either sandy or gravelly sediments or unstable clayey sediment. The dominant coastal plain soils in the Baltimore metropolitan area consist of Typic Hapludults. Soils in the Piedmont Plateau of the Baltimore region are very deep, moderately sloping, well drained upland soils that are underlain by semi-basic or mixed basic and acidic rocks. The dominant piedmont soils in the Baltimore area consist of Ultic Hapludalfs. Highly disturbed soils make up more than 60 percent of the land area of urbanized areas of the watershed.

Research and Facilities

The BES study area includes nearly 60,000 ha of intact forests, some 120 years old or more. In the Baltimore metropolitan region, a small network of permanent plots in urban and rural forest remnants has been established to measure ecosystem processes over time within an urban-rural gradient framework. In addition, Baltimore was one of the first cities where Urban FIA plots were established in various urban land-use and cover types. These plots are revisited every 7 years to measure changes in urban forest structure. The BES also has established a hierarchical network of 14 USGS stream-gauging stations that represent a gradient of urban development, ranging from small, single land-use watersheds to larger and complex watersheds that integrate all of the principal study area. In so doing, advantage was taken of differences in socio-economic factors, land use, and cover among the smaller watersheds in the hierarchy to set up comparisons much like the gradient analysis of remnant forest patches described above. The network includes a reference area in an entirely forested watershed. 

Lat: 39°24´47˝ N, long. 76°31´19˝ W

Contact Information

Baltimore Ecosystem Study c/o
USDA Forest Service Baltimore Field Station
5523 Research Park Drive, Suite 350
Baltimore, MD 21228

Major Research Accomplishments and Effects on Management

• The most dense network of urban watershed monitoring stations in the country (14 gauging stations installed)
• Measuring community well-being and relating this to stewardship
• Developing new tools that can improve local resource management and planning
• Development of innovative non-point source, non-structural (using trees and other vegetation) storm water management techniques
• Measurement of urban forest ecosystem services and monitoring long-term health of both urban trees and forest patches
• Supporting the Urban Field Station Collaborative Arts and Urban Waters Federal Partnership Programs
• Assessing and mapping environmental governance networks
• Understanding long-term dynamics of environmental justice
• Measured surface water salt contamination and spatial patterns of soil contamination
• Measuring urban carbon cycle

GIS data bases include geology, soils, land use, long-term social demography, historic land use and cover, urban infrastructure, and tree canopy cover, among others. 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. Environmental governance network surveys and household surveys of environmental perceptions, attitudes, and behaviors have also been collected since 1999. Data associated with the Baltimore Ecosystem Study are available through the Environmental Data Initiative.