DOI: 10.1007/s10533-013-9873-x
Scopus记录号: 2-s2.0-84897397381
论文题名: Is the high 15N natural abundance of trees in N-loaded forests caused by an internal ecosystem N isotope redistribution or a change in the ecosystem N isotope mass balance?
作者: Högberg P. ; Johannisson C. ; Högberg M.N.
刊名: Biogeochemistry
ISSN: 0168-2563
EISSN: 1573-515X
出版年: 2014
卷: 117, 期: 2018-02-03 起始页码: 351
结束页码: 358
语种: 英语
英文关键词: Ectomycorrhiza
; Forest soils
; N-15 natural abundance
; Nitrogen deposition
Scopus关键词: concentration (composition)
; denitrification
; ectomycorrhiza
; forest ecosystem
; forest soil
; isotopic fractionation
; mass balance
; nitrogen compound
; nitrogen cycle
; nitrogen isotope
; soil profile
; Fungi
英文摘要: High δ15N of tree foliage in forests subject to high N supply has been attributed to 15N enrichment of plant available soil N pools after losses of N through processes involving N isotope fractionation (ammonia volatilization, nitrification followed by leaching and denitrification, and denitrification in itself). However, in a long-term experiment with high annual additions of NH4NO3, we found no change in the weighted average δ15N of the soil, but attributed the high δ15N of trees to loss of ectomycorrhizal fungi and their function in tree N uptake, which involves redistribution of N isotopes in the ecosystem (Högberg et al. New Phytol 189:515-525, 2011), rather than a loss of isotopically light N. Here, we compare the effects of additions of urea and NH4NO3 on the δ15N of trees and the soil profile, because we have previously found higher δ15N in tree foliage in trees in the urea plots. Doing this, we found no differences between the NH4NO3 and urea treatments in the concentration of N in the foliage, or the amounts of N in the organic mor-layer of the soil. However, the foliage of trees receiving the highest N loads in the urea treatment were more enriched in 15N than the corresponding NH4NO3 plots, and, importantly, the weighted average δ15N of the soil showed that N losses had been associated with fractionation against 15N in the urea plots. Thus, our results in combination with those of Högberg et al. (New Phytol 189:515-525, 2011) show that high δ15N of the vegetation after high N load may be caused by both an internal redistribution of the N isotopes (as a result of change of the function of ectomycorrhiza) and by losses of isotopically light N through processes fractionating against 15N (in case of urea ammonia volatilization, nitrification followed by leaching and denitrification). © 2013 The Author(s). Citation statistics:
资源类型: 期刊论文
标识符: http://119.78.100.158/handle/2HF3EXSE/83668
Appears in Collections: 气候减缓与适应 气候变化事实与影响
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作者单位: Department of Forest Ecology and Management, Swedish University of Agricultural Sciences (SLU), Umeå, 901 83, Sweden
Recommended Citation:
Högberg P.,Johannisson C.,Högberg M.N.. Is the high 15N natural abundance of trees in N-loaded forests caused by an internal ecosystem N isotope redistribution or a change in the ecosystem N isotope mass balance?[J]. Biogeochemistry,2014-01-01,117(2018-02-03)