Boggs Johnny L, McNulty Steven G, Pardo Linda H
Southern Global Change Program, Southern Research Station, USDA Forest Service, 920 Main Campus Drive, Suite 300, Venture Center II, Raleigh, NC 27606, USA.
Environ Pollut. 2007 Oct;149(3):303-14. doi: 10.1016/j.envpol.2007.05.013. Epub 2007 Jun 27.
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.
1987/1988年，我们在东北地区11个红云杉（Picea rubens Sarg.）站点评估了沿氮沉降梯度的叶和林地化学性质；1999年，我们在6个成对的云杉和落叶林站点评估了叶和林地化学性质以及断面积生长情况。这6个红云杉样地是1987/1988年原始云杉站点的一个子集。1999年，我们观察到生长季平均温度与红云杉断面积生长之间存在显著相关性。红云杉和落叶树叶的氮含量百分比与氮沉降显著相关。尽管从1987/1988年到1999年氮沉降没有显著变化，但怀特菲什山的净硝化潜力显著下降。净硝化潜力的这种下降与氮饱和假说不一致，这表明非氮沉降控制因素，如气候因素和倒下枯木的固定作用，可能限制了氮循环。
