RESEARCH OVERVIEW

    The Bear Brook Watershed in Maine (BBWM) research program is centered on two small first-order adjacent forested stream watersheds in eastern Maine.  The research was begun in the mid-1980s as part of the national agenda of research to determine the effects of acid deposition on surface waters and their related watersheds.  Since then, the BBWM program of research has grown to encompass an array of scientific objectives that include acid deposition, climate change and carbon sequestration, nitrogen saturation, base cation depletion, and studies of the evolution of watershed biogeochemistry under prolonged experimental acidification.  The primary principal investigators for this research are faculty at the University of Maine, with strong collaborations with the USDA Forest Service and the US Geological Survey.  However, many other scientists and students from other institutions have and continue to work at BBWM. 

Research at the BBWM site is internationally recognized for its contributions to understanding the effects of elevated nitrogen (N) and sulfur (S) deposition on forested watersheds through whole-ecosystem experimental manipulations.  Monitoring of the paired catchments began in 1987. Chemical additions of N and S, as (NH₄)₂SO₄, have been delivered bimonthly via manual and helicopter applications to the West Bear watershed since November, 1989 and continue through to the present. The adjacent untreated East Bear watershed serves as a reference. Precipitation and stream chemistry, along with hydrological flux, result in the core input/output fluxes of these watersheds. Publications from this research program can provide details of the methodology and findings.

SITE DESCRIPTION

    The Bear Brook Watershed in Maine is the site of a long-term, gaged, forested, first order paired stream watershed located in eastern Maine (44^o52' N lat., 68^o6' W long.) approximately 40 km from the Atlantic Ocean. The site lies on the southeast slope of Lead Mountain, with total relief of 210 m and a maximum elevation of 475 m. Two nearly perennial, low DOC, low ANC streams (East and West Bear Brook) drain 10.3 and 11.0 ha contiguous watersheds. Vegetation at the site is dominated by northern hardwoods (Fagus grandifolia Ehrb., Acer rubrum L., Acer saccharum Marsh., Betula alleghaniensis Britt., Betula paprifera Marsh., and Acer pensylvaticum Marsh.) with stands of softwoods dominated by red spruce (Picea rubens Sarg.) but including other softwoods (Abies balsamea Mill., and Tsuga canadensis (L.) Carr.) at higher elevations. Soils are coarse, loamy, mixed, frigid Typic Haplorthods developed on till averaging one meter in thickness. Bedrock is quartzites and meta-pelites intruded locally by granite. Hydrologic flux from the watersheds is gaged with V-notch weirs in collaboration with the US Geological Survey.  The US Geological Survey posts real time discharge for East Bear and West Bear on the internet.

Contact Information:   

Support for the BBWM program of research has been provided from a wide range of resources that include the U.S. Environmental Protection Agency, the USDA Forest Service, the National Science Foundation, the Maine Agricultural and Forest Experiment Station at the University of Maine, International Paper, and GMO Renewable Resources.

The University of Maine, Orono, Maine 04469 A Member of the University of Maine System 207-581-1110