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Changes in conifer and deciduous forest foliar and forest floor chemistry and basal area tree growth across a nitrogen (N) deposition gradient in the northeastern US

Informally Refereed

Abstract

We evaluated foliar and forest floor chemistry across a gradient of N deposition in the Northeast at 11 red spruce (Picea rubens Sarg.) sites in 1987/1988 and foliar and forest floor chemistry and basal area growth at six paired spruce and deciduous sites in 1999. The six red spruce plots were a subset of the original 1987/1988 spruce sites. In 1999, we observed a significant correlation between mean growing season temperature and red spruce basal area growth. Red spruce and deciduous foliar %N correlated significantly with N deposition. Although N deposition has not changed significantly from 1987/1988 to 1999, net nitrification potential decreased significantly at Whiteface. This decrease in net potential nitrification is not consistent with the N saturation hypothesis and suggests that non-N deposition controls, such as climatic factors and immobilization of down dead wood, might have limited N cycling.

Keywords

N saturation, spruce-fir, N deposition gradient, northern hardwood forests

Citation

Boggs, Johnny L.; McNulty, Steven G.; Pardo, Linda H. 2007. Changes in conifer and deciduous forest foliar and forest floor chemistry and basal area tree growth across a nitrogen (N) deposition gradient in the northeastern US. Environmental Pollution, Vol. 149: 303-314
https://www.fs.usda.gov/research/treesearch/28962