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 |
| |
Authors: | Boggs Johnny L McNulty Steven G Pardo Linda H |
| |
Institution: | Southern Global Change Program, Southern Research Station, USDA Forest Service, 920 Main Campus Drive, Suite 300, Venture Center II, Raleigh, NC 27606, USA. jboggs@ncsu.edu |
| |
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: | |
本文献已被 PubMed 等数据库收录! |
|