CALM
SITE
Dot
Lake
|
|
|
Site Code |
U58 |
|
Site Name |
ALN-DOT |
|
CAPS 1 Metadata
form |
|
|
CAPS 2 Metadata
form |
|
|
Responsible for
data submission |
Leah M Mackey |
|
Email Address |
|
|
Institution/Organization |
YRITWC/USGS |
|
Location
Description |
Interior-Subarctic |
|
Location Lat. |
N63.67475 |
|
Location Long. |
W144.14597 |
|
Elevation avg.
(m) |
|
|
Methods Grid |
no grid – single
500 m transect |
|
Methods Other |
Soil moisture,
soil temp., air temp |
|
Landscape
Description |
Dense to
scattered stunted to full size spruce forest on slight sloping hillside at
base of mountainous area, tussock, moss and game trails |
|
Vegetation/Classification |
stuntedàfull size black spruce, willows,
cottonwood, moss/lichen, small plants and grasses. |
|
Soils (or
Material) |
Organic black
soil, decomposing material, |
|
Thaw depth
measurements (year started) |
2010 |
|
Air temp.
measurements (year started) |
2010 |
|
Snow Cover
measurements (year started) |
N/A |
|
Soil temp.
measurements (start year) |
2010 |
|
Soil moisture
measurements (start year) |
2010 |
|
General
description of soil moisture |
moist in root
zoneàwet towards permafrost |
|
Soil texture: if
non organic describe texture, if organic indicate thickness of organic layer
(cm) |
~ 48cm sphagnum
moss/lichen mat ~ 35cm
decomposing organic soil ~21cm dark black
moist organic soil |
DESCRIPTION
OF AREA CONTAINING SITE:
Dot Lake is an extremely small
community along the Alaska Highway. The ALN site is located between milepost
1365-1364, approximately 5 miles north of Dot Lake Village. As you head south
on the Alaska Hwy the site is just past the state sign posting “Tok Jct. 50mi, Tetlin Jct. 62mi”.
Pull over on the South side of the road about 200 yds
past the sign. Walk south into the trees about 200 yards. At second major game
trail look for post 21 and the air sensor on a spruce tree. Trail runs east to
west. The area vegetation is sparsely to heavily forested, with small clearings
and trails. Black spruce dominates the landscape, as well as other shrubs,
trees, moss and lichen cover.
The site was established in 2010 as a
demo/test site for a different style of installation – as opposed to the 50x50m
grid. The site was installed as a
continuous line following a game trail. The mid-point of the line is found at
N63.67475 W144.14597 and contains continuous soil temperature & soil
moisture sensors at ‘above permafrost’ & ‘just below surface’ levels. An
air temperature sensor is installed on a spruce tree near stake 21. All sensors
collect and store data on a 30-minute continuous cycle. Each stake and/or measurement was made about
1 meter south of the trail. The goal of the site it to
include more forested sites into the overall project coverage. Open
areas tend to be favored for site selection due to accessibility and ease of
installation. As an observation, it
seems that open areas are more prone to thaw than those with canopy cover. 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.
SOIL
DESCRIPTION:
The soil is characterized by moist to
wet dark rich organic soil with partially decomposed plant matter.
SAMPLING
DESIGN AND METHOD:
The Dot Lake site was chosen to
increase the range of distribution of Active Layer Network sites that are
predominately forest.
The site consist
of a single 500 meter line with stakes every 10 meters and measurements made
every 5 meters, for a total of 100 data points. A game trail was followed and
orange flags placed at trail diversions to mark the location. Measurements were
taken about 1 meter off (south) of the trail every 5 meters. 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, due to the slight modification of the site setup, we consider this
site a test site and should not be said to follow CALM protocols.]
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 ~30cm4 hole was dug
down to the permafrost layer at 48cm. 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 48cm and 25cm
(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.
REFERENCES: