Nenana

Created: 2014-01-31 12:37:33
Modified: 2014-01-31 12:51:15

DESCRIPTION OF AREA CONTAINING SITE:

Nenana Alaska is located at mile 305 of the Parks Highway. This historic community / Athabascan Native Village is 56 miles from Fairbanks and 75 miles north of Denali National Park. The ALN grid site is located off 9th street on the South side of the gravel road. The area is open and marshy on the South side with sparse trees, the North side of the road is treed to the road. Medium to large tussock cover the open area with alders, willows, woody plants and tall grasses. Many of the vegetation appeared dead. The 50mx50m grid, established in 2010, is marked with survey stakes along the North and South sides in 5-meter intervals. The grid center contains continuous soil temperature & soil moisture sensors at above permafrost & just below surface levels. The NW corner of the grid is marked w/ two crossed stakes (N64.55, W149.08). An air temperature sensor is installed on a small evergreen tree near grid center, the micro station is located on the West side of the tree w/ the air sensor. All sensors collect and store data on a 30-minute continuous cycle. The grid was established in 2010 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 Nenana site was chosen to increase the range of distribution of Active Layer Network sites.

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 50m 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 68cm. 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 68cm and 9cm (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 111m, recorded at grid center.