|
Study Number: |
1014 |
|---|---|
|
Project Title: |
Nitrogen transformation along an elevational and vegetative gradient. |
|
Investigator(s): |
Jennifer D. Knoepp E-Mail | Tel. 828.524.2128 x103 | Biographical Sketch |
| Affiliated Institution(s): | USDA Forest Service |
| Address: |
Coweeta Hydrologic
Laboratory 3160 Coweeta Lab Road Otto, North Carolina 28763 USA |
| Study Type: | Terrestrial |
| Project Type: | Coweeta Core Research |
| Study Period: |
05/01/1991 - 01/10/1995 |
| Status/Notes: | |
| Funding Source(s): |
National Science Foundation, DEB-9632854 (Text Version) and DEB-0218001 (Text Version) to Coweeta LTER. |
| Abstract: |
Examination of N-transformation along
elevation and vegetation gradient. These measurements are analysis of
plant nitrogen availability and overall site productivity. Resources
for students about terms used
in this study:Nitrogen cycle - Source: Visionlearning.com |
| Location(s), Described: |
Watershed 18
and
Watershed 27. See Project Summary Sheet 1048 and Terrestrial Gradient Sites: Characteristics (photographs) for detailed information about plot locations and physical descriptions, respectively. |
| Location(s), Download GPS: | ArcView Shape Files (shp.): UTM, NAD83, Zone 17 | Lat/Lon |
| Location(s), Online Map(s): |
 USGS Topographic-based Maps of Research Sites(Printable for fieldwork) |
| Methods/Experimental Design: | Potential nitrogen transformation rates (net nitrification and mineralization) are measured using closed core in situ incubations of the 0-10 cm of mineral soil for 28 days. Two cores are driven into the top 10 cm of soil 25 cm apart. One core is removed and represents time equals 0 (t = 0) NH4+ and NO3- concentrations. The other core is capped with a PVC cap and left in place for 28 days. Incubations are performed at randomly selected points on each of four transects on each LTER plot, these transects are used as replicates. Three sets of nitrogen transformation measurements are conducted on the extensive plots. NH4+ and NO3- nitrogen concentrations are measured in fresh soil sieved (< 6mm) extracted with 2 M KCl (10 g soil : 20 ml KCl) for 1 hour. |
| Sampling Frequency: | Bimonthly. |
| Data Columns: |
Site - Site number (See Locations, Described
above) Plot - Plot locations code Sample - Sampling dates (0 - 28 of 28 day in situ closed core incubation period) Nitrif - Net change in soil NO3--N concentration over the 28 day incubation period D_NH4 - Net change in soil NH4+-N concentration over the 28 day incubation period MIN - Net change in soil NH4+-N + NO3--N concentration over the 28 day incubation period NO3_0 - Soil NO3--N concentration in t = 0 soil collected for N transformation measurements. Analyzed on Technicon using hydrazine reduction. NH4_0 - Soil NH4+-N concentration in t=0 soil collected for N transformation measurements. Analyzed on Technicon using alkaline phenol method. Plot codes: P - Main plot T - Jim Vose's productivity tower, 527 and 427, Canopy walkway 218 F - Forest health monitoring site 527 FR - Forest health monitoring site under rhododendron 527 L - Litter decomposition site 218 L11 - Litter trap 427 Missing Data Codes: . (Period) |
| Publications: |
Knoepp, Jennifer Donaldson; Swank, Wayne T. 1995. Comparison of available soil nitrogen assays in control and burned forested sites. Soil Science Society of America Journal. 59: 1750-1754. |
| Data Restrictions: | Users must adhere to the Coweeta LTER Data Policy. |
| Metadata: | EML Format (XML Schema) | Information about EML |
| Data Downloads: |
Microsoft® Excel (.xls) Text Comma Delimited (.csv) DBase (.dbf) |