US EPA

6981207 

Journal Article 

Effect of gap size on litter decomposition and soil nitrate concentrations in a high-elevation spruce-fir forest 

Prescott, CE; Hope, GD; Blevins, LL; , 

2003 

Yes 

Canadian Journal of Forest Research
ISSN: 0045-5067
EISSN: 1208-6037 

NATL RESEARCH COUNCIL CANADA 

OTTAWA 

2210-2220 

10.1139/X03-152 

WOS:000186558300017 

Possible mitigation of nitrate losses associated with clearcuts through harvesting smaller gaps was tested in a high-elevation forest of Engelmann spruce (Picea engelmannii Parry ex Engelm.) and subalpine fir (Abies lasiocarpa (Hook.) Nutt.). We measured concentrations of ammonium and nitrate after 6-week buried bag incubations of forest floor and mineral soil samples in replicated plots of uncut forest and gaps of 10, 1.0, and 0.1 ha and single-tree removal for 7 years after harvest. Nitrate concentrations in forest floor and mineral soil were elevated 3-7 years after harvesting in gaps of 0.1 ha and larger. Removal of the same proportion of trees as single trees did not result in increased nitrate concentrations, suggesting that nitrate losses could be reduced by harvesting single trees rather than creating gaps. Greater N availability was not associated with faster rates of decomposition of litter and forest floor, which were similar in gaps of all sizes (0-10 ha). Reciprocal transplant of forest floor and soil from the 10-ha gaps and the uncut forests indicated that changes in the nature of the forest floor or soil following harvest had a greater influence on nitrate concentrations than the changes in environmental conditions in the gaps.