DOI: 10.1007/s10533-014-9983-0
Scopus记录号: 2-s2.0-84904797046
论文题名: Land use and hydrologic flowpaths interact to affect dissolved organic matter and nitrate dynamics
作者: Toosi E.R. ; Schmidt J.P. ; Castellano M.J.
刊名: Biogeochemistry
ISSN: 0168-2563
EISSN: 1573-515X
出版年: 2014
卷: 120, 期: 2018-01-03 起始页码: 89
结束页码: 104
语种: 英语
英文关键词: Cultivation
; Dissolved organic C (DOC)
; Dissolved organic N (DON)
; Land-use
; Soil depth
; Subsoil
英文摘要: The transport and transformation of dissolved organic matter (DOM) and dissolved inorganic nitrogen (DIN) through the soil profile impact down-gradient ecosystems and are increasingly recognized as important factors affecting the balance between accumulation and mineralization of subsoil organic matter. Using zero tension and tension lysimeters at three soil depths (20, 40, 60 cm) in paired forest and maize/soybean land uses, we compared dissolved organic C (DOC), dissolved organic N (DON) and DIN concentrations as well as DOM properties including hydrophilic-C (HPI-C), UV absorption (SUVA254), humification index and C/N ratio. Soil moisture data collected at lysimeter locations suggest zero tension lysimeters sampled relatively rapid hydrologic flowpaths that included downward saturated flow through the soil matrix and/or rapid macropore flow that is not in equilibrium with bulk soil solution whereas tension lysimeters sampled relatively immobile soil matrix solution during unsaturated conditions. The effect of land use on DOC and DON concentrations was largely limited to the most shallow (20 cm) sampling depth where DOC concentrations were greater in the forest (only zero tension lysimeters) and DON concentrations were greater in the cropland (both lysimeter types). In contrast to DOC and DON concentrations, the effect of land use on DOM properties persisted to the deepest sampling depth (60 cm), suggesting that DOM in the cropland was more decomposed regardless of lysimeter type. DOC concentrations and DOM properties differed between lysimeter types only in the forest at 20 cm where soil solutions collected with zero tension lysimeters had greater DOC concentrations, greater SUVA254, greater humification index and lower HPI-C. Our data highlight the importance of considering DOM quality in addition to DOC quantity, and indicate long-term cultivation reduced the delivery of relatively less decomposed DOM to all soil depths. © 2014 Springer International Publishing Switzerland. Citation statistics:
资源类型: 期刊论文
标识符: http://119.78.100.158/handle/2HF3EXSE/83714
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 Agronomy, Iowa State University, Ames, IA, United States; Pasture Systems and Watershed Management Research Unit, Agricultural Research Service, USDA, University Park, PA, United States
Recommended Citation:
Toosi E.R.,Schmidt J.P.,Castellano M.J.. Land use and hydrologic flowpaths interact to affect dissolved organic matter and nitrate dynamics[J]. Biogeochemistry,2014-01-01,120(2018-01-03)