| Title: |
del 15N Values for Tanana River Floodplain Soils and Xylem Sap Samples
|
| Contacts: |
Kielland, Knut
Olson, Karl
|
| Abstract: |
Because soil microoorganisms preferencially discriminate either for or against heavy nitrogen isotopes in organic compounds we can learn something about the route these compounds take through any given system by looking at the isotopic ratio of heavy to light nitrogen within a pool as compared to the ratio for the system as a whole. An enriched pool means that 15N has been discriminated for, while a depleted pool means 15N has been discriminated against. By determining the del 15N values for soil protein, amino acids, ammonium, the soil microbial population, and plant roots and xylem we can learn something about where plants are deriving there nitrogen nutrition.
|
| Keywords: |
amino acids, ammonium, floodplain, isotope, nitrogen, roots, soil, xylem, |
| Categories: |
Biogeochemistry
|
| Study Period: |
Oct 24, 2002 to Oct 24, 2002
|
| Bounding Box: |
West longitude: -148.3790685°
North latitude: 64.7666796°
East longitude: -148.1435205°
South latitude: 64.66966°
|
| Site References: |
BP1 -- True balsam poplar stand on the Tanana River floodplain within Bonanza Creek Experimental Forest, Fairbanks, Alaska, USA. Vegetation structure for these sites includes a closed canopy of mature (>100 yrs old) balsam poplar with a dense thin-leaf alder (Alnus
tenuifolia) understory. Basal area for stems larger than 5 cm averages
36.7 m2 ha-1 and 1.8 m2 ha-1 for balsam poplar and alder, respectively, with densities for poplar ranging from 567 to 922 stems ha-1 among the three stands. Total litterfall averaged 279 g m-2 y-1 across the three stands during the 1998–99 growing season. Rose (Rosa acicularis) and high-bush cranberry (Viburnum edule) are prominent within the shrub layer, filling understory canopy gaps previously occupied by decadent alder shrubs. Average daily soil temperatures measured at a depth of 7 cm during the 1998 growing season ranged from a minimum of 3.8°C in May to a maximum of 11.4°C in late July. The soil, classified as typic cryofluvent, consists of an alluvium of fine to medium sand grains overlain by a well-developed organic profile extending to more than 8 cm in some places.
Soil C:N ratios average 19.0 for the organic layer and 16.0 for the mineral soil.
BP2 -- True balsam poplar stand on the Tanana River floodplain within Bonanza Creek Experimental Forest, Fairbanks, Alaska, USA. Vegetation structure for these sites includes a closed canopy of mature (>100 yrs old) balsam poplar with a dense thin-leaf alder (Alnus
tenuifolia) understory. Basal area for stems larger than 5 cm averages
36.7 m2 ha-1 and 1.8 m2 ha-1 for balsam poplar and alder, respectively, with densities for poplar ranging from 567 to 922 stems ha-1 among the three stands. Total litterfall averaged 279 g m-2 y-1 across the three stands during the 1998–99 growing season. Rose (Rosa acicularis) and high-bush cranberry (Viburnum edule) are prominent within the shrub layer, filling understory canopy gaps previously occupied by decadent alder shrubs. Average daily soil temperatures measured at a depth of 7 cm during the 1998 growing season ranged from a minimum of 3.8°C in May to a maximum of 11.4°C in late July. The soil, classified as typic cryofluvent, consists of an alluvium of fine to medium sand grains overlain by a well-developed organic profile extending to more than 8 cm in some places.
Soil C:N ratios average 19.0 for the organic layer and 16.0 for the mineral soil.
BP3 -- True balsam poplar stand on the Tanana River floodplain within Bonanza Creek Experimental Forest, Fairbanks, Alaska, USA. Vegetation structure for these sites includes a closed canopy of mature (>100 yrs old) balsam poplar with a dense thin-leaf alder (Alnus
tenuifolia) understory. Basal area for stems larger than 5 cm averages
36.7 m2 ha-1 and 1.8 m2 ha-1 for balsam poplar and alder, respectively, with densities for poplar ranging from 567 to 922 stems ha-1 among the three stands. Total litterfall averaged 279 g m-2 y-1 across the three stands during the 1998–99 growing season. Rose (Rosa acicularis) and high-bush cranberry (Viburnum edule) are prominent within the shrub layer, filling understory canopy gaps previously occupied by decadent alder shrubs. Average daily soil temperatures measured at a depth of 7 cm during the 1998 growing season ranged from a minimum of 3.8°C in May to a maximum of 11.4°C in late July. The soil, classified as typic cryofluvent, consists of an alluvium of fine to medium sand grains overlain by a well-developed organic profile extending to more than 8 cm in some places.
Soil C:N ratios average 19.0 for the organic layer and 16.0 for the mineral soil.
FP1A -- FP1A is located on a low early successional terrace (1.8 - 2 m above winter low river level) adjacent to the Tanana River. Vegetation establishment occurred in 1982 to 1983. Significant bank erosion has occurred since the establishment of the study area, resulting in loss of some study plots.
FP1B -- FP1B is located on a low early successional terrace adjacent to the Tanana River.
FP1C -- FP1C is located on a low early successional terrace adjacent to the Tanana River.
FP4A -- Mature white spruce
FP4B -- Mature white spruce
FP4C -- Mature white spruce
UP2A -- Closed Mixed White Spruce - Paper Birch Stand
UP2B -- Closed Mixed White Spruce - Paper Birch Stand
UP2C -- Closed Mixed Aspen - White Spruce Stand
UP3A -- Mature white spruce spruce stand on a south-facing slope
UP3B -- Closed White Spruce Forest
UP3C -- Closed White Spruce Forest
|
| Data Columns: |
| Column |
Name |
Units |
Type |
| 1 |
Sample Name |
|
string |
| 2 |
N Amp. |
V |
float |
| 3 |
Mass N |
mg |
float |
| 4 |
d15N |
|
float |
|
| Data File(s): |
154_1432_del15N.txt
|
| Supplemental Files: |
|
| Metadata Formats: |
|
| Public Release: |
Oct 15, 2002
|
| Publications: |
|
|
The Bonanza Creek LTER, including this website, is supported by the
National Science Foundation through awards
DEB-0620579,
DEB-0423442,
DEB-0080609,
DEB-9810217,
DEB-9211769,
DEB-8702629
and by the USDA Forest Service, Pacific Northwest Research Station through agreement number RJVA-PNW-01-JV-11261952-231.
Any opinions, findings, conclusions, or recommendations expressed in the
material are those of the author(s) and do not necessarily reflect
the views of the supporting agencies or the program as a whole.
© Bonanza Creek LTER, 2009.
Last modified 23-Nov-09
UAF is an affirmative action/equal opportunity employer and educational institution.
This site is a member of the LTER Network.
Disclaimer
|
|
