DOI: 10.1007/s10533-015-0153-9
Scopus记录号: 2-s2.0-84948100927
论文题名: Direct response of dissolved organic nitrogen to nitrate availability in headwater streams
作者: Wymore A.S. ; Rodríguez-Cardona B. ; McDowell W.H.
刊名: Biogeochemistry
ISSN: 0168-2563
EISSN: 1573-515X
出版年: 2015
卷: 126, 期: 2018-01-02 起始页码: 1
结束页码: 10
语种: 英语
英文关键词: Dissolved organic nitrogen
; Nitrate
; Nitrogen cycling
; Organic matter
; Stream ecosystems
英文摘要: Despite decades of research documenting the quantitative significance of dissolved organic nitrogen (DON) across ecosystems, the drivers controlling its production and consumption are not well understood. As an organic nutrient DON may serve as either an energy or nitrogen source. One hypothesized control on DON concentration in streams is nitrate (NO3 −) availability. Synoptic surveys of DON and NO3 −, however, have yielded inconsistent spatial and temporal patterns. Using a nutrient pulse method we experimentally manipulated stream NO3 − and measured the response of both the manipulated solute and ambient concentrations of DON in three New Hampshire headwater streams. This direct experimental addition of NO3 − often altered ambient DON concentrations in situ, with both increases and decreases observed. The overall relationship between NO3 − and DON suggests that DON is primarily used as a nutrient source in these streams, as evidenced by net DON accumulation with added NO3 −. However, strong underlying seasonal patterns in the response to NO3 − addition are also discernable, indicating that the role of DON can switch between serving as a nutrient source to an energy source (as evidenced by net DON reduction with added NO3 −). We also observed differences in the NO3 −—DON relationship (net DON accumulation vs. net DON reduction) in two streams less than five miles apart when experiments were conducted within the same month. Based on these results, we expect the role of DON within ecosystems to vary among watersheds and throughout the growing season, alternating between serving as a nutrient and energy source depending on environmental conditions. With the incorporation of a new field-based method we demonstrate that the ambient DON pool can be manipulated in situ. This approach has the potential for furthering our understanding of DON across ecosystems. © 2015, Springer International Publishing Switzerland. Citation statistics:
资源类型: 期刊论文
标识符: http://119.78.100.158/handle/2HF3EXSE/83455
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 Natural Resources and the Environment, University of New Hampshire, 114 James Hall, 56 College Road, Durham, NH, United States
Recommended Citation:
Wymore A.S.,Rodríguez-Cardona B.,McDowell W.H.. Direct response of dissolved organic nitrogen to nitrate availability in headwater streams[J]. Biogeochemistry,2015-01-01,126(2018-01-02)