Robert Stottlemyer 14181 North County Road, 25E Loveland, Colorado 80538 970.223.1628 rstottle@earthlink.net
The northern hardwood Calumet watershed (176-ha) and conterminous lands (approximately 200 ha) are located in the Great Lakes Climate Domain. Site coordinates (watershed mouth) are lat 47° 17’ N, 88° 34’ W (see attached file). This RFI is for a core wildland site, and addresses both Grand Challenge questions but primarily the second. The proposed hardwood experimental area is midway in elevation along the eastern boundary of the watershed.
The three largest of the Great Lakes dominate much of the climate in the Domain. The Calumet watershed is adjacent the south shore of Lake Superior 16 km north of Michigan Technological University, Houghton, Michigan. The watershed is located within the North-Central Lake-Swamp-Moraine Plains Physiographic Division. It has a NW aspect, uniform slope, moderate topographic relief with elevation from 190 m at the mouth to 370 m in the headwaters. The bedrock is predominantly Cambrian Freda sandstones overlain with alkaline till and old beach deposits. Soils are mainly Typic Haplorthods, sandy, mixed, frigid.
The Calumet watershed is located within the sensitive ecotone between northern hardwood and boreal forest along the southern boundary of latitudes 45° - 65° N where climate simulations predict the most temperature rise, precipitation loss, and vegetation migration. This ecotonal reach covers about 60% of the area in the Great Lakes Climate Domain. The watershed is vegetated by sugar maple (Acer saccharum Marshall) and white birch (Betula papyrifera Marshall), and includes hardwood-dominated and white cedar (Thuja occidentalis) wetlands. The forest age is 80+ years. The watershed is representative of the maple-beech-birch forest type which dominates Northern Michigan, Michigan’s Upper Peninsula, Northern Ohio and Pennsylvania, New York, Vermont, New Hampshire, and Western Maine along with southern Ontario and Quebec.
Continuous monitoring of watershed hydrology, meteorology, precipitation and stream chemistry began in autumn 1979. Research has focused on longer-term trends in snowpack physical and chemical character along an elevation gradient, snowmelt pattern and links to subsurface flow paths, and watershed solute inputs and outputs including dissolved inorganic and organic carbon and nitrogen (see Site Publications below). Monitoring includes an upper and lower recording stream gage (pressure transducer, datalogger); air, snowpack, stream and soil temperature; radiation flux; and weekly precipitation and snowpack water equivalent (SWE) along an elevation gradient.
Since the mid 1980’s data from NOAA station 3908 (8 km to south) show a decline in annual precipitation (-2 cm yr-1) and an increase in average winter temperature (0.7o C) relative to the previous 30 year record. Our Calumet studies show a sharp increase with elevation in winter precipitation, the SWE, solute inputs, and a decline in temperature. Snow cover duration, SWE, snowmelt (-0.8 cm yr-1), and annual runoff (-1.04 cm yr-1) all decline since the mid 1980’s. The winter declines have occurred at all stations independent of elevation, but the decreases are most pronounced at low elevations. Despite warmer and drier winters and reductions in SWE and snowmelt, at the watershed level the percentage of winter runoff that occurs when subsurface lateral flow is shallow (<25 cm) increased 2% yr-1. By the mid 1990’s at Calumet, the gains in shallow sub-surface lateral flow resulted in a threshold change of increased stream water concentration and output of dissolved inorganic nitrogen (DIN), dissolved organic nitrogen (DON), and dissolved organic carbon (DOC).
The watershed has year-round paved road access and power. Proximity to the university greatly simplifies potential logistical problems with site visits and timely sample preparation and analysis. We also operate NADP station MI99 (20+ yr record) on the university campus.