Aluminum in soil solutions from a subalpine spruce-fir forest at Whiteface Mountain, New York.
1992
Miller E.K. | Huntington T.G. | Johnson A.H. | Friedland A.J.
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 [Abies balsamea (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 micromole L-1) associated with reduced root growth in red spruce (Picea rubens Sarg.). Over a 2-yr period ambient soil solutions averaged 76 and 46 micromole L-1 total Al in the organic and mineral horizons, respectively. The highest monthly mean concentrations occurred in winter. Disturbance-induced NO3 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.
显示更多 [+] 显示较少 [-]