DOI: 10.1007/s10533-017-0332-y
Scopus记录号: 2-s2.0-85017523791
论文题名: Distinct fates of atmogenic NH4 + and NO3 − in subtropical, N-saturated forest soils
作者: Yu L. ; Kang R. ; Mulder J. ; Zhu J. ; Dörsch P.
刊名: Biogeochemistry
ISSN: 0168-2563
EISSN: 1573-515X
出版年: 2017
卷: 133, 期: 3 起始页码: 279
结束页码: 294
语种: 英语
英文关键词: 15N tracer
; Denitrification
; Gross N transformation
; N deposition
; N2O emission
; Nitrate leaching
; Nitrification
Scopus关键词: biogeochemistry
; denitrification
; leaching
; nitrate
; nitrogen
; nitrous oxide
; transformation
英文摘要: Subtropical forests receive increasing amounts of atmogenic nitrogen (N), both as ammonium (NH4 +) and nitrate (NO3 −). Previous long-term studies indicate efficient turnover of atmogenic NH4 + to NO3 − in weathered, acidic soils of the subtropics, leading to excessive NO3 − leaching. To clarify the mechanism governing the fate of atmogenic inputs in these soils, we conducted an in situ 15N tracing experiment in the TieShanPing (TSP) forested catchment, SW China. 15NH4NO3, NH4 15NO3 and 15N-glutamic acid were applied to an upland hillslope soil and inorganic N, total soil N and nitrous oxide (N2O) were monitored for nine days. Incorporation of 15NO3 − into soil organic N was negligible and 80% of the applied label was lost from the top soil (0–15 cm) primarily by leaching within 9 days. In contrast, 15NH4 + was largely retained in soil organic N. However, instant production of 15NO3 − in the 15NH4 + treatment suggested active nitrification. In both the 15NH4 + and 15N-glutamic acid treatments, the 15N enrichment in the NO3 − pool exceeded that in the NH4 + pool one day after 15N application, suggesting preferential nitrification of added 15NH4 + with subsequent dilution of the NH4 + pool and/or immobilization of 15NH4 + followed by heterotrophic nitrification. The cumulative recovery of 15N in N2O after 9 days ranged from 2.5 to 6.0% in the 15NO3 − treatment, confirming the previously reported significant response of N2O emission to N deposition. Source partitioning of 15N2O demonstrated a measurable contribution of nitrification to N2O emissions, particularly at low soil moistures. Our study emphasizes the role of a fast-cycling organic N pool (including microbial N) for retention and transformation of atmogenic NH4 + in subtropical, acid forest soils. Thus, it explains the near-quantitative leaching of deposited N (as NO3 − and NH4 +) common to subtropical forest soils with chronic, elevated atmogenic N inputs by (i) negligible retention of NO3 − in the soil and (ii) rapid immobilization-mineralization of NH4 + followed by nitrification. Our findings point to a leaky N cycle in N-saturated Chinese subtropical forests with consequences for regional soil acidification, N pollution of fresh waters and N2O emission. © 2017, Springer International Publishing Switzerland. Citation statistics:
资源类型: 期刊论文
标识符: http://119.78.100.158/handle/2HF3EXSE/83275
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: Faculty of Environmental Sciences and Natural Resource Management, Norwegian University of Life Sciences, Post box 5003, Aas, Norway; Department of Environment and Resources, Guangxi Normal University, Guilin, China
Recommended Citation:
Yu L.,Kang R.,Mulder J.,et al. Distinct fates of atmogenic NH4 + and NO3 − in subtropical, N-saturated forest soils[J]. Biogeochemistry,2017-01-01,133(3)