Marcell Experimental Forest

Marcell Experimental Forest (MEF) is a 1,140 ha long-term ecosystem research site operated by the Northern Research Station of the U.S. Forest Service.^[1] It is located 40 km north of Grand Rapids, Minnesota within the Chippewa National Forest and was formally established in 1962 to study the ecology and hydrology of peatland watersheds.^[2][1] There are six experimental watersheds each of which consist of an upland portion, a peatland, and an outlet stream.^[3] The range of these six watersheds provide a variety of hydrological environments to study.^[3] Climatic and hydrologic data have been continuously monitored since 1961.^[3][4] Some notable research areas have been hydrology, nutrient and mercury cycling and behavior, and release of organic carbon and acidity.^[3]

Entrance sign to the South Unit.

MEF is the longest running National Atmospheric Deposition Program (NADP) site in the nation.^[1]

Climate and physical characteristics

Peatlands and lakes comprise 30% of the forest landscape at the MEF.^[1] The peatlands include fens and bogs. The peatlands may be treeless or have tree cover and the forested bogs contain black spruce and tamarack.^[1] Both forested and open bogs are dominated by Sphagnum and ericaceous shrubs. Fens also include northern white cedar and black ash.^[1]

The climate is subhumid continental with moist warm summers and relatively dry, cold, and sunny winters including large diurnal and seasonal temperature fluctuations. The extreme low temperature is -50.8 °F, extreme high temperature is 100.4 °F, and the average annual air temperature is 38.1 °F.^[1] The average temperature at MEF has risen about 0.72 °F per decade since the 1960s.^[1]

Mean annual precipitation is 30.4 inches with 75% occurring in the snow-free period.

The pH of waters in the bogs range from about 3.5 to 4.5 with the fens having a pH of near neutral.

Facilities

The Marcell Research Center has a heated shop, laboratory, conference facility and living quarters for up to eight visiting researchers and graduate students.^[1]

Spruce and Peatland Responses Under Changing Environments (SPRUCE) project is located within MEF and is a climate change manipulation study.^[1][5] This is a 10+ year, large scale Department of Energy sponsored experiment that is a collaboration between the US Forest Service Northern Research Station and Oak Ridge National Laboratory and involves 100+ scientists from around the world.^[1] Large chambers have been built to test the effect of elevated temperature and elevated carbon dioxide on bog vegetation and carbon dynamics.