Dynamic species-specific metabolic changes in the trees exposed to chronic N+S additions at the Bear Brook Watershed in Maine, USA

Increased deposition of atmospheric nitrogen leads to changes in forest productivity. Effects of added nitrogen+sulfur (N+S) on tree physiology and forest health will yield information on species-specific sensitivity to N+S. To evaluate these metabolic changes we compared foliage (from 1998-2000 and again in 2013) and sapwood (only in 2013) from American beech, sugar maple and red spruce at West Bear Watershed (WBW) in Maine, that have been treated with (NH4)2SO4 (ammonium sulfate) since 1989 with that from the East Bear Watershed in Maine, which served as an untreated reference (Minocha et al. 2019). Included in this package are the results of these data analyzed for polyamines (PA), amino acids (AA), perchloric acid (PCA) soluble ions, total chlorophyll and soluble proteins using high performance liquid chromatography (HPLC), inductively coupled plasma emission spectrometry (ICP), and absorption spectrometry methods.The purpose of this study was to evaluate the long-term metabolic effects of chronic nitrogen+sulfur (N+S) additions on foliage and sapwood of American beech, sugar maple and red spruce at the Bear Brook Watershed in Maine, USA.For more details about this study and the Bear Brook Watershed in Maine see: https://umaine.edu/bbwm/. Original metadata date was 11/15/2018. Minor metadata updates were made on 04/09/2019.