Country: United States
Site: Allakaket CALM-Code: U52
Timezone: UTC/GMT -09:00 hours
Vegetation Type: Forest Tundra
Responsible Person: Leah M. Mackey
Offset: 5 m
DESCRIPTION OF AREA CONTAINING SITE:
Allakaket is on the south bank of the Koyukuk River, southwest of its junction with the Alatna River, approximately 190 nautical miles (350 km) northwest of Fairbanks and 57 miles (92 km) upriver from Hughes. The village of Alatna is located directly across the river. The 50mx50m grid site is located in the open area directly behind the Tribal Office. The NW corner of the grid starts about 50yds diagonally from the SW corner of the building. The area is flat hummocky tundra with grasses, moss/lichen, small wooded brush (alder) and 2 stunted black spruce are w/in the grid. The grid, established in 2010, is marked at 5-meter intervals with surveyor stakes along the North and South sides of the grid. The grid center (N66.54 W152.64, 20m south of stake 6) contains continuous soil temperature & soil moisture sensors at “above permafrost” & “just below surface” levels. An air temperature sensor is installed on a spruce tree NE of grid center. All sensors collect and store data on a 30-minute continuous cycle. The grid was established in 2010, with assistance from Allakaket Traditional Council, in the second year of a cooperative agreement with the Yukon River Inter-Tribal Watershed Council and the U.S. Geological Survey.
SAMPLING DESIGN AND METHOD:
The Allakaket site was chosen to increase the range of distribution of Active Layer Network sites. Assistance from the Allakaket Traditional Council in land permission and permafrost laden location was given.
The grid consists of 2 parallel lines of 10 survey stakes at 5-meter intervals, creating a 50mx50m square grid with a maximum of 100 data points. A compass was used to orientate the grid to a square. Active Layer measurements were taken manually every 5m and recorded on a fieldsheet. The measurements were taken at the lowest surface level within about 0.3m of the designated point, to minimize the questionable influence of tussocks on the AL measurement. The "surface level" was determined to be the top of the low-lying vegetation (i.e. moss, lichen, low-bush berries). Thaw measurements greater than 1.3m were noted, but not used in calculations, as of 2009. [CALM protocol suggests a grid size of 100mx100m, however a 50m2 grid was deemed acceptable due to difficult terrain and length of time for installation (personal communication Dr. V.Romanovsky).]
The soil climate station was established in early September 2010 and is located near grid center. The station monitors air temperature, soil temperature & soil moisture.The
HOBO micro station was installed at the grid center. A ~30cm hole was dug down to the permafrost layer at 70cm. One set of soil moisture and soil temperature sensors were placed just above the permafrost layer and one set just below surface level.
Soil samples were cut from 67cm and 37cm (cubes) to be analyzed for soil moisture content. The
HOBO pro v2 temp/ext temp sensor was installed, recording air temperature, near the grid center about one meter off the ground surface. The Hobo data logger is set to store data on 30min intervals for up to 428 days.
GPS points were taken at the four corners of the grid, as well as the center point where the sensors were located. Site elevation is 135m, recorded at grid center.