Description and field performance of the Walker Branch throughfall displacement experiment: 1993--1996
- Oak Ridge National lab., TN (United States). Environmental Sciences Div.
- Tennessee Valley Authority, Norris, TN (United States)
- Univ. of Tennessee, Knoxville, TN (United States). Inst. of Agriculture
The authors are conducting a large-scale manipulative field experiment in an upland oak forest on the Walker Branch Watershed in eastern Tennessee to identify important ecosystem responses that might result from future precipitation changes. The manipulation of soil water content is being implemented by a gravity-driven transfer of throughfall from one 6400-m{sup 2} treatment plot to another. Throughfall is intercepted in {approx}1850 subcanopy troughs suspended above the forest floor of the dry plot and transferred by gravity flow across an ambient plot for subsequent distribution onto the wet treatment plot. Soil water content is being monitored at two depths with time domain reflectometers at 310 sampling locations across the site. The experimental system is able to produce statistically significant differences in soil water content in years having both dry and wet conditions. Maximum soil water content differentials between wet and dry plots in the 0- to 0.35-m horizon were 8 to 10% during summers with abundant precipitation and 3 to 5% during drought periods. Treatment impacts on soil water potential were restricted to the surface soil layer. Comparisons of pre- and post-installation soil and litter temperature measurements showed the ability of the experimental design to produce changes in soil water content and water potential without creating large artifacts in the forest understory environment.
- Research Organization:
- Oak Ridge National Lab., Environmental Sciences Div., TN (United States)
- Sponsoring Organization:
- USDOE, Washington, DC (United States); USDOE Office of Energy Research, Washington, DC (United States)
- DOE Contract Number:
- AC05-96OR22464
- OSTI ID:
- 296852
- Report Number(s):
- ORNL/TM-13586; R&D Project: ERKP514; ON: DE98058143; BR: KP1203010; TRN: AHC29903%%250
- Resource Relation:
- Other Information: DN: Environmental Sciences Division publication number 4753; PBD: Apr 1998
- Country of Publication:
- United States
- Language:
- English
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A large-scale throughfall manipulation experiment on Walker Branch Watershed
A large-scale throughfall manipulation experiment on Walker Branch Watershed