Created: 2014-02-03 14:19:22
Modified: 2015-11-09 16:11:02
DESCRIPTION OF AREA CONTAINING SITE:
U7B 1-ha grid is located within of the U7A 1 km grid.
Site description: Flat with mixed flat-centered and low-centered polygons; moist nonacidic tundra.
Vegetation communities: (1) Raised microsites, including polygon rims and raised centers: Moist Eriophorum triste, Carex membranacea, Dryas integrifolia, Tornentypnurn nitens, Thamnolia subuliformis graminoid, prostrate-shrub tundra. (2) Lower microsites, mainly polygon basins: Wet Eriophorum angustifolium, Carex aquatilis, Drepanocladus brevifolius graminoid tundra.Cover of top 5 species: Eriophorum triste (22%), Dryas integrifolia (16%), Tomentypnum nitens (7%), Eriophorum vaginatum (4%), Carex aquatilis (2%).
Mean vegetation height: 3.1 +/- 3.0 s.d. cm
Mean live moss layer thickness: 1.8 +/- 0.9 cm
Organic layer thickness: 12 +/- 1.7 cm.
(Walker and Bockheim, 1995)
SAMPLING DESIGN AND METHOD:
Beginning in 1995, the active layer has been probed at least annually at the site. The procedure involves pushing a metal rod, calibrated in cm, to the point of refusal, interpreted in most cases to be the frost table. Thaw depth measurements at each site were obtained by probing at 5 m intervals along the plot’s two perpendicular and one diagonal transect, resulting in 71 points per plot per probing date.
In 1995 the site was instrumented with several OnsetTM portable data loggers connected to probe-type thermistors. Each logger/thermistor system has an effective temperature range of -50oC to +33oC and resolution of approximately 0.32oC. At each site, one thermistor was placed in a radiation shield approximately 2 m above the ground surface, and nine loggers were placed at the interface between mineral soil and organic material in various microtopographic positions within the site. Temperature measurements were collected at, 1 hr, and 2 hr intervals depending on season, and year. Details on methodology are provided in Klene et. al 2001.
This soil climate station was established in June of 1996 and is located on the British Petroleum (BP) Prudhoe Bay oil field near Betty pingo within U7a and U7b CALM sites. The elevation is about 12 m (40 ft). This station monitors air temperature, soil temperature at various depths to a maximum of 120 cm, and soil water content at 10, 25, and 40 cm depths. Measurements are made at 20-minute intervals and averaged and recorded every hour.
Soil temperature and soil moisture metadata and data are also available at http://soils.usda.gov/survey/scan/alaska/BettyPingo/
Additional Climate data are also available at http://www.uaf.edu/water/projects/NorthSlope/coastal_plain/betty/betty.html
CALM USA George Washington University
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