Soil acidification and element fluxes of a Fagus Sylvatica forest as influenced by simulated nitrogen deposition

• Published in: Water, air, and soil pollution air, and soil pollution, 1992-10, Vol.65 (1-2), p.111-133
• Main Authors: BERGKVIST, B, FOLKESON, L
• Format: Article
• Language: English
• Subjects: Agronomy. Soil science and plant productions; Biological and medical sciences; Fagus sylvatica; Fundamental and applied biological sciences. Psychology; Soil and water pollution; Soil science
• ISSN: 0049-6979; 1573-2932
• DOI: 10.1007/bf00482753

The influence of simulated 3- and 9-fold increases in the current N deposition on element fluxes and soil acidification was investigated in a beech forest in S Sweden. Treatments, in three replicates, were 66 and 198 kg N ha super(-1) yr super(-1) as NH sub(4)NO sub(3) during 5.5 yr. All the supplied N could not be accounted for by leaching or soil accumulation, and possible pathways are discussed. Leaching of NO sub(3) super(-) increased greatly upon treatment. Nitrification, also occurring in the control soil, was considerably enhanced by the low-N but not by the high-N treatment. Leaching of NO sub(3) super(-) (added or resulting from nitrification) had a strongly acidifying influence. Soil-soiution (cup lysimeters at 30 cm depth) pH was 4.51, 4.07 and 3.81 in the control, low- and high-N plots, respectively. The buffering of protons shifted from the base-cation to the Al buffer range. The base-cation/Al ratio (equivalents) of cation mobilization was 2.7 in the control, 1.1 in low-N and 0.15 in high-N plots. Also Mn and Rb fluxes were drastically increased. The G:N ratio of beech litterfall decreased with increasing N supply but fluxes of elements in litterfall and in throughfall were not influenced. The bulk deposition of N was 18 kg ha super(-1) yr super(-1).