Published in Applied Geochemistry 26: 2181-2190<\/b><\/p>\n
The concentrations and the isotopic compositions of S, N and C were studied in soils and in the dominant plant species of three forested watersheds (Qu\u00e9bec, Canada) located along a latitudinal and atmospheric deposition gradient. Large increases in S, N and C isotope ratios (up to 3.9\u2030, 10\u2030, 2.6\u2030, respectively) were observed with increasing soil depth at the three watersheds. These increases were accompanied by a strong decrease in elemental concentrations resulting in a strong negative relationship between these two variables. Both S and N concentrations throughout the soil profile and d34<\/sup>S and d15<\/sup>N in the mineral soil appeared to increase with increasing S and N deposition rates and decreasing latitude. A strong positive linear relationship was found between d34<\/sup>S and d15<\/sup>N (R2<\/sup><\/em> = 0.72) values and between organic S and N concentrations (R2 = 0.96) in soils. The slope of the linear relationship between d34<\/sup>S and d15<\/sup>N (d34<\/sup>S = f(d15<\/sup>N)) indicated that isotopic fractionation was almost 4 times higher for S than for N during transformations that occurred in soil. However, this difference might reflect a higher degree of openness of the S cycle compared to the N cycle rather than an isotope effect per se<\/em>. Overall, the results suggest that N and S inputs significantly impact the isotope ratios and the concentrations of N and S in the soils, and that S and N were closely associated and subject to similar processes with the same isotopic effects throughout the soil profile. Contrary to most studies, d34<\/sup>S-SO4<\/sub> in stream water of the most northerly site with the lowest S deposition rate was significantly higher than d34<\/sup>S-SO4<\/sub> in atmospheric depositions but similar to the d34<\/sup>S of the bulk mineral soil. It suggests that the mineral soil actually contributes a large portion of the stream S-SO4<\/sub> for this site.<\/p>\n","protected":false},"excerpt":{"rendered":" Published in Applied Geochemistry 26: 2181-2190 The concentrations and the isotopic compositions of S, N and C were studied in soils and in the dominant plant species of three forested watersheds (Qu\u00e9bec, Canada) located along a latitudinal and atmospheric deposition gradient. Large increases in S, N and C isotope ratios (up to 3.9\u2030, 10\u2030, 2.6\u2030, […]<\/p>\n","protected":false},"template":"","format":"standard","cptt_secteur":[1179],"cptt_theme":[1183,1185,1180,1181],"cptt_categ_publi":[1149],"cptt_auteurs_ministeriels":[1082,1091],"class_list":["post-82427","cpt_publication","type-cpt_publication","status-publish","format-standard","hentry","cptt_secteur-forests","cptt_theme-ecosystems-and-environment","cptt_theme-forest-ecology","cptt_theme-forestry-research","cptt_theme-forests","cptt_categ_publi-scientific-article","cptt_auteurs_ministeriels-duchesne-louis","cptt_auteurs_ministeriels-d-houle"],"acf":[],"yoast_head":"\n