Thomas G. Huntington A. H. Johnson A. J. Friedland E. K. Miller 1992 <p><span>Direct or indirect Al toxicity has been suggested as a principal factor in forest tree declines. We monitored ambient soil solutions in undisturbed and experimentally manipulated soils from a fir [</span><i>Abies balsamea</i><span>&nbsp;(L.) Mill.]-spruce forest on Whiteface Mountain, NY, in order to characterize soil solution Al concentrations over a range of acid anion loadings. Under both natural and experimental conditions total Al and labile Al concentrations rarely exceeded values (180–250 µmol L</span>⁻¹<span>) associated with reduced root growth in red spruce (</span><i>Picea rubens</i><span>&nbsp;Sarg.). Over a 2-yr period ambient soil solutions averaged 76 and 46 µmol L</span>⁻¹<span>&nbsp;total Al in the organic and mineral horizons, respectively. The highest monthly mean concentrations occurred in winter. Disturbance-induced NO</span>₃<span>&nbsp;accumulation and simulated acid rain applications produced higher peak Al values in experimental plots than were observed in undisturbed and untreated plots. Although soils of the fir-spruce zone exhibited the potential to yield solutions with phytotoxic Al concentrations, it appears that such concentrations are both spatially and temporally limited and infrequently present a direct stress to root growth in red spruce.</span></p> application/pdf 10.2134/jeq1992.00472425002100030007x en ACSESS Aluminum in soil solutions from a subalpine spruce-fir forest at Whiteface Mountain, New York article