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Study Number: |
1069 |
|---|---|
|
Project Title: |
Examining the potential effects of phytophagous insect frass on forest nitrogen cycling. |
|
Investigator(s): |
Mark D. Hunter
Biographical
Sketch (Retired) Bradley Balukjian Note: Researcher is retired. For further information regarding this project, please contact: Coweeta LTER Coweeta Hydrologic Laboratory 3160 Coweeta Lab Road Otto, North Carolina 28763 USA Telephone: 828.524.2128 | FAX: 828.369.6768 |
| Affiliated Institution(s): | University of Georgia |
| Address: |
Institute of Ecology University of Georgia Athens, Georgia 30602 USA |
| Study Type: | Terrestrial |
| Project Type: | Type 1 |
| Study Period: |
05/1999 - 12/2001 |
| Status/Notes: |
Graduate Research |
| Funding Sources: |
National Science Foundation, DEB-9632854 (Text Version) and DEB-0218001 (Text Version) to Coweeta LTER. |
| Abstract: |
Human alteration of the
global nitrogen cycle has increased the importance of understanding the
major sources, sinks, and fluxes of the cycle within natural ecosystems.
One poorly understood component of the nitrogen cycle in forest
ecosystems is the contribution of phytophagous insect frass on soil
N-cycling dynamics. This study proposes to investigate the influence of
frass on (1) the dynamics of soil N-cycling; (2) the loss of N from the
ecosystem via leaching; (3) the slow cycle decomposition of
post-herbivore leaf litter; and (4) the overall potential of soil near
the Coweeta Hydrologic Laboratory to retain nitrogen. Red Oak (Quercus
rubra [Fagaceae]) saplings will be subjected to defoliation by the
seasonal phytophagous insect larvae of the White-Marked Tussock Moth (Orgyia
leucostigma [Lepidoptera: Lymantriidae]) and the frass added to the soil
in a factorial, controlled experimental design. Soil nutrient
concentrations, leachate nutrient concentrations, "soil" respiration,
and leaf quality will be measured. The project is expected to increase
our understanding of the complex relationship between above-ground and
below-ground nitrogen cycling dynamics as well as inform the current
debate concerning the relative impacts and importance of human versus
natural alterations to the nitrogen cycle. Resources
for students about terms used in this study:The nitrogen cycle - Source: Visionlearning Red oak - Source: USDA Plants Database Whitemarked Tussock Moth - Source: forestpests.org |
| Location(s), Described: | In watershed 27, approximately .5km past the gate at the Pickin's Nose trail head, there is what appears to be an abandoned roadway with a steep entrance. The "road" leads to the remnants of a campfire site just after the entrance. North of the small camp clearing there is a downed tree and an area with canopy cover but no trees. |
| Location(s), Download GPS: | ArcView Shape Files (shp.): UTM, NAD83, Zone 17 | Lat/Lon |
| Location(s), Online Maps: | Online Map |
| Methods/Experimental Design: |
We are conducting a
microcosm experiment to attempt to replicate Barbara Reynolds' results of a
NO3 pulse in the soil and catchment drainage stream following a
Periclista sp. outbreak (Reynolds,
Barbara, C.; Hunter, Mark D.; Crossley, D.A., Jr. 2000.
Effects of
Canopy Herbivory On Nutrient Cycling In A Northern Hardwood Forest In
Western North Carolina. Selbyana. 21(1.2): 74-78).
We are using Quercus rubra saplings and Orgyia leucostigma (White Marked Tussock Moths) in the experimental system, and will be measuring nitrate concentrations in the soil and leachate. In order to closely replicate field conditions, we would like to remove a relatively small amount of surface litter and soil from a high-elevation site near Kitti's high elevation site. Saplings were shipped in 3-gallon pots and will be potted up to 7-gallon pots for the experiment. There are 8 treatments with 20 replicates/treatment, for a total of 160 trees. Each pot has a volume of approximately .34 m^3, and approximately half of each pot will require soil, as each sapling is in a potting soil mix currently. From these calculations, it is estimated that approximately 2.046 m^3 of soil and surface litter will be required. |
| Sampling Frequency: | A single removal period that will be broken into two or three consecutive trips. |
| Data Columns: |
Date - Date (month-year) |
| Publications: |
Frost, Christopher J.; Hunter, Mark D. 2004. Insect canopy herbivory and frass deposition affect soil nutrient dynamics and export in oak mesocosms. Ecology. 85(12): 3335-3347. |
| 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) |