DOI: 10.1007/s10533-016-0286-5
Scopus记录号: 2-s2.0-85007239975
论文题名: Erosional redistribution of topsoil controls soil nitrogen dynamics
作者: Berhe A.A. ; Torn M.S.
刊名: Biogeochemistry
ISSN: 0168-2563
EISSN: 1573-515X
出版年: 2017
卷: 132, 期: 2018-01-02 起始页码: 37
结束页码: 54
语种: 英语
英文关键词: Coupled C and N cycling
; Soil erosion
; Soil nitrogen
; Soil organic matter
Scopus关键词: carbon cycle
; carbon sequestration
; landform
; nitrogen cycle
; residence time
; soil erosion
; soil nitrogen
; soil organic matter
; soil profile
; topsoil
; watershed
; California
; United States
英文摘要: In recent years, the role of soil erosion on terrestrial carbon sequestration had been the focus of a growing number of studies. However, relatively little attention has been paid so far to the role of erosion on the lateral distribution of soil nitrogen (N) and the role of geomorphic processes on soil N dynamics. Here, we present primary data on the stock of nitrogen in soil and its rate of erosion at a relatively undisturbed, zero-order watershed in northern California. Erosion transports 0.26–0.47 g N m−2 year−1 from eroding slope positions (Summit and Slope), and about two-thirds of the eroded N enters depositional landform positions (Hollow and Plain). Our results show that depositional-position soil profiles contain up to 3 times more N than soil profiles in the eroding positions. More than 92% of all soil nitrogen was chemically bound to soil minerals in all the landform positions, compared to 2–4% each found in the free light and occluded light fractions. Nitrogen associated with the free light fraction in topsoil is particularly susceptible to loss by soil erosion. By comparison, soil N associated with the aggregate-protected occluded light fractions and the mineral-associated dense fractions is likely to be protected from gaseous and dissolved losses. On average, we found that soil N has mean residence time of 694 years in eroding landform positions, compared to 2951 years in depositional landform positions. Our results also show that microbial processing of organic matter exerts strong control on overall soil N storage and N stabilized through sorptive interactions with soil minerals only in poorly drained depositional landform positions. Soil erosion exerts important control on stock, distribution, and long-term fate of soil N in dynamic landscapes. © 2016, Springer International Publishing Switzerland. Citation statistics:
资源类型: 期刊论文
标识符: http://119.78.100.158/handle/2HF3EXSE/83311
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: Life and Environmental Sciences, School of Natural Sciences, University of California, 5200 N. Lake Rd, Merced, CA, United States; Earth Science Division, Lawrence Berkeley National Laboratory; and Earth and Resources Group, University of California, Berkeley, CA, United States
Recommended Citation:
Berhe A.A.,Torn M.S.. Erosional redistribution of topsoil controls soil nitrogen dynamics[J]. Biogeochemistry,2017-01-01,132(2018-01-02)