TY - JOUR
T1 - The effects of throughfall manipulation on soil leaching in a deciduous forest
AU - Johnson, D. W.
AU - Hanson, P. J.
AU - Todd, D. E.
PY - 2002
Y1 - 2002
N2 - The effects of changing precipitation on soil leaching in a deciduous forest were examined by experimentally manipulating throughfall fluxes in the field. In addition to an ambient treatment (AMB), throughfall fluxes were reduced by 33% (DRY treatment) and increased by 33% (WET treatment) using a system of rain gutters and sprinklers on Walker Branch Watershed, Tennessee. Soil leaching was measured with resin lysimeters in the O horizons and with ceramic cup lysimeters in the E (25 cm) and Bt (70 cm) horizons. Large and statistically significant treatment effects on N fluxes were found in the O horizons (lower N fluxes in the DRY and higher N fluxes in the WET treatment). Together with the greater O horizon N content observed in the DRY treatment, this suggested that N was being immobilized at a greater rate in the DRY treatment than in the AMB or WET treatments. No statistically significant treatment effects on soil solution were found in the E horizons with the exception of (Ca2+ + Mg2+) to K+ ratio. Statistically significant treatment effects on electrical conductivity (EC), pH, Ca2+, Mg2+, K+, Na+, SO42-, and Cl- were found in the Bt horizons due to differences between the DRY and other treatments. Despite this, calculated fluxes of Ca2+, Mg2+, K+, Na+, SO42-, and Cl- were lowest in the DRY treatment. These results suggest that lower precipitation will cause temporary N immobilization in litter and long-term enrichment in soil base cations whereas increased precipitation will cause long-term depletion of soil base cations.
AB - The effects of changing precipitation on soil leaching in a deciduous forest were examined by experimentally manipulating throughfall fluxes in the field. In addition to an ambient treatment (AMB), throughfall fluxes were reduced by 33% (DRY treatment) and increased by 33% (WET treatment) using a system of rain gutters and sprinklers on Walker Branch Watershed, Tennessee. Soil leaching was measured with resin lysimeters in the O horizons and with ceramic cup lysimeters in the E (25 cm) and Bt (70 cm) horizons. Large and statistically significant treatment effects on N fluxes were found in the O horizons (lower N fluxes in the DRY and higher N fluxes in the WET treatment). Together with the greater O horizon N content observed in the DRY treatment, this suggested that N was being immobilized at a greater rate in the DRY treatment than in the AMB or WET treatments. No statistically significant treatment effects on soil solution were found in the E horizons with the exception of (Ca2+ + Mg2+) to K+ ratio. Statistically significant treatment effects on electrical conductivity (EC), pH, Ca2+, Mg2+, K+, Na+, SO42-, and Cl- were found in the Bt horizons due to differences between the DRY and other treatments. Despite this, calculated fluxes of Ca2+, Mg2+, K+, Na+, SO42-, and Cl- were lowest in the DRY treatment. These results suggest that lower precipitation will cause temporary N immobilization in litter and long-term enrichment in soil base cations whereas increased precipitation will cause long-term depletion of soil base cations.
UR - http://www.scopus.com/inward/record.url?scp=0036154477&partnerID=8YFLogxK
U2 - 10.2134/jeq2002.2040
DO - 10.2134/jeq2002.2040
M3 - Article
C2 - 11837424
AN - SCOPUS:0036154477
SN - 0047-2425
VL - 31
SP - 204
EP - 216
JO - Journal of Environmental Quality
JF - Journal of Environmental Quality
IS - 1
ER -