Forest research at the Turkey Lakes Watershed

The 10.5 km 2 Turkey Lakes Watershed, located on the Precambrian Shield approximately 60 km north of Sault Ste. Marie, Ontario, is occupied by a typical Great Lakes-St. Lawrence sugar maple-yellow birch forest. Since late 1979, the watershed has been the site of an interdisciplinary study on impacts of long-range transported air pollutants on the biology of forests, lakes and streams, and the recovery of terrestrial and aquatic ecosystems in response to reduced pollutant deposition. A knowledge base on forest growth, soils and hydrology, with detailed climate and precipitation chemistry records dating back nearly twenty years has been developed. This history, plus an available infrastructure, makes the watershed an ideal site to study processes across the terrestrial-aquatic interface. A harvesting impacts project, for example, was started in 1997. This project is built around a field experiment comparing clear-felling, shelterwood, and single-tree selection versus uncut control, for appropriateness of application and for impacts on long-term soil productivity, stand function, diversity of plant and animal life, and hydrological and other on- and off-site impacts. The watershed is also a site for the ECOLEAP Project, which is attempting to improve overall understanding of mechanisms controlling forest productivity, and a site to test terrain and climate models to model temperature, moisture, energy and nutrients and the relationship of these to species distribution, abundance and productivity at different scales up to the watershed level. Key words: acid precipitation, air pollution, biogeochemistry, research site, watershed