Nitrogen export from a watershed subjected to partial salvage logging.
Logging has been shown to induce nitrogen (N) leaching. We hypothesized that logging a watershed that previously exhibited forest decline symptoms would place additional stress on the ecosystem and result in greater N loss, compared to harvesting vigorous forests. We conducted a 10-year (1988 to 1998) assessment of N export from the Baldwin Creek watershed in southwestern Pennsylvania that was partially clearcut to salvage dead and dying northern red oak. N export from the watershed increased significantly following salvage logging operations and did not completely return to prelogging levels by the end of the study period. The largest annual NO3-N export of 13 kg/ha was observed during the first year after harvesting, an increase of approximately 10 kg/ha. Compared to data from other Appalachian Mountain watersheds in North Carolina, West Virginia, and Pennsylvania, calculated N loss for Baldwin Creek was considerably greater. Longer periods of reduced N uptake due to slow revegetation of salvage logged areas, coupled with increased amounts of N available to leaching, could have accounted for the large N losses observed for Baldwin Creek. Salvage logging of dead and dying trees from forested watersheds in this region appears to have the potential to result in much larger N losses than previously reported for harvest of healthy stands.
Herrmann
M
M
School of Forest Resources and Environmental Resources Research Institute, The Pennsylvania State University, University Park 16802, USA.
Sharpe
W E
WE
DeWalle
D R
DR
Swistock
B R
BR
D017753:Ecosystem; D016468:Forestry / Q000706:statistics & numerical data*; D005618:Fresh Water / Q000737:chemistry; D009566:Nitrates / Q000032:analysis; D009584:Nitrogen / Q000032:analysis / Q000378:metabolism; D010414:Pennsylvania; D012987:Soil / Q000032:analysis; D014197:Trees / Q000737:chemistry / Q000378:metabolism
D009566:Nitrates; D012987:Soil; D009584:Nitrogen