|
CALM SITE U18 |
BONANZA CREEK |
|
Site code |
U18 |
|
Site name |
Bonanza Creek |
|
CAPS I
Metadata form |
GGD281 |
|
CAPS II
Metadata form |
GGD313U_18 |
|
Responsible
for data submission |
Brian Charlton |
|
Email Address |
Fnbac1”-at-”uaf.edu |
|
Institution/Organization |
|
|
Location
description |
Subarctic Alaska |
|
Location Lat. |
64 deg. 45 min. N |
|
Location Lon. |
148 deg. 00 min. W |
|
Elevation avg.
(m) |
129 |
|
Methods Grid |
50x60 |
|
Methods Other |
Air Temperature, Soil temperature |
|
Landscape
Description |
Old
terrace, south side Tanana River |
|
Vegetation
/Classification |
Open black spruce forest |
|
Soils (or
Material) |
Pergelic Cryaquepts |
|
Thaw depth measurements (year started)
|
1990 |
|
Air temp. measurements (year started) |
NA |
|
Snow cover measurements (year started) |
NA |
|
soil temp. measurements (year
started) |
1992 |
|
soil moisture measurements (year started) |
1999 |
|
general description of soil moisture (dry, moist,
wet, saturated) |
Moist |
|
soil texture: if non organic describe texture, if
organic indicate thickness of organic layer (cm) |
24 cm |
|
|
|
DESCRIPTION
OF AREA CONTAINING SITE:
The
Bonanza Creek Long Term Ecological Research (LTER) site is located on an old
terrace on the south side of Tanana River adjacent to the Bonanza Creek
Experimental Forest at an elevation of 129 m and at the following GPS
coordinates: 64o 42”N; 148o 08”W.
The study site was established in 1987 as part of a network of LTER sites and
is adjacent to a permanent plot established by L.A. Viereck
in 1965. The designation of the site in the LTER terminology is FP5C –
indicating that it is one of a replicate of four black spruce stands (5A-5D) in
the successional sequence on the floodplain (FP) of
the Tanana River. The vegetation of the site consist
of open black spruce with widely scattered individuals of tamarack (Larix laricina). It
is classified as an open black spruce forest (Open Picea mariana/Alnus crispa-Ledum groennlandicum-Vaccinium
vitis-idaea/Hylocomium splendens-Pleurozium schreberi community) (Viereck
et al, 1993). Total tree canopy is 32%. Tree density in 1989 totaled 2684
trees/ha. Average diameter is 15 cm and heights range from 10 to 15 m. A
complete description of the FP5C site with a photograph can be seen on the
Bonanza Creek LTER web site: http://www.lter.uaf.edu/site.cfm?site_pkey=30
NEW INFO!
On June 12th, 2010
lightning ignited a wildfire in the area of FP5C (U18). Due to the equipment risk the
meteorological station was removed at this time, though the soil sensors were
left in the ground. The fire was
slow to spread, however warm weather conditions and high winds eventually
pushed the fire closer to the research site. Some time near the end of July the site
was burned. The slow moving nature
of the fire consumed nearly the entire organic mat including tree roots. Most of the standing trees in the area
subsequently fell to the ground though their boles were not consumed (see
photo). The plot location markers
were relocated in late August and the meteorological station was
reestablished. The original soil
temperature sensor wires were repaired without disturbing their locations and
all previous measuring activities were resumed. A Campbell Scientific, Inc. camera was
installed at the site and can be seen at http://www.lter.uaf.edu/bnz_webCamera.cfm
SOIL
DESCRIPTION: (predominant
texture, i.e., ‘sand’, ‘gravel’, ‘peat’,
etc.):
The
soil at this site is classified as a Pergelic Cryaquepts and is in the Tanana Soil Series. At this site
the 01 and 02 layers of moss and decaying organic material averages 24 cm in
thickness. A complete description and profile of the FP5 sites soils and a
diagram of the successional sequence on the Tanana
River floodplain are given in Van Cleve, Viereck, and
Dyrness 1996.
SAMPLING
DESIGN AND METHOD:
Although the site was established
in 1987, measurements of the annual active layer thickness were not started
until September of 1990. In 1992 a weather station was established at the site
that records hourly air temperatures and soil temperatures at depths of 0, 5,
10, 20, 50, 100, and 200 cm. In addition a 20-meter long, 10 point
transect with a board walk was installed in 1992 to measure the seasonal thaw
of the active layer. The CALM measurements are not taken from that probe line.
Instead the depth of thaw for the CALM data is obtained from a 20 point grid
that is part of 50 by 60 meter vegetation plot at the site. The individual
probe sites are in a 4 x 5 grid of permanent
vegetation plots that are 10 meters apart. The probing of the active layer is
made at a fixed distance and direction from the center point of each of the
vegetation plots in mid to late September. The site was missed in 1993.
REFERENCES:
Van Cleve, K.,
Viereck,
Viereck,
List of additional publications on the site is
available at http://www.lter.uaf.edu/pubs/publications.cfm
Only
thaw depth data determined by mechanical probing and air and soil temperature
for several years are reported on CALM website. For additional data refer to http://www.lter.uaf.edu/ or contact site investigators directly