|
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 |
Karl
Olson |
|
Email Address |
kdolson@alaska.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