DOI: 10.1007/s10533-016-0205-9
Scopus记录号: 2-s2.0-84962656190
论文题名: Denitrification in a subtropical, semi-arid North American savanna: field measurements and intact soil core incubations
作者: Soper F.M. ; Groffman P.M. ; Sparks J.P.
刊名: Biogeochemistry
ISSN: 0168-2563
EISSN: 1573-515X
出版年: 2016
卷: 128, 期: 2018-01-02 起始页码: 257
结束页码: 266
语种: 英语
英文关键词: di-nitrogen
; Grassland
; N-FARM
; Nitric oxide
; Nitrous oxide
; Prosopis
Scopus关键词: denitrification
; field method
; flux measurement
; nitric oxide
; nitrous oxide
; Northern Hemisphere
; savanna
; shrub
; soil analysis
; soil column
; soil nitrogen
; subtropical region
; wetting
; Australia
; Texas
; United States
; Prosopis
英文摘要: Information on denitrification (particularly N2) losses from dry ecosystems is limited despite their large area. Here, we present the first direct denitrification measurements for a northern hemisphere savanna, a Prosopis-dominated grassland/grove matrix in south Texas. We used the gas-flow intact soil core method to quantify N2, N2O and CO2 losses and compared these with field measurements of N2O, NOy, NH3 and CO2. Under field-realistic soil moisture and O2 conditions (average 17.5–20 % O2, minimum 15 %) incubated soils produced no measurable N2 flux (detection limit 52.2 µg N m−2 h−1). Only in a subset of grove soils were fluxes of 70–75 µg N m−2 h−1 recorded after 102 h of incubation at 5–10 % O2 following wetting of very dry soils. Making the assumption that potential N2 production falls just below the detection limit (likely an overestimate given the conditions needed to generate measurable fluxes), N2 flux rates would fall on the low end of that recorded for a tropical Australian savanna (45–110 µg N m−2 h−1) under comparable abiotic conditions. Assuming maximum possible production rates, N2 could comprise <32–76 % of total soil N gas flux following soil wetting in summer. Lack of flux response to soil wetting in winter suggests that cold-season N2 fluxes are negligible. N2O fluxes for core incubations were significantly higher than for field chambers; thus it is likely that incubations may overestimate N2O flux by reducing soil column consumption. Overall, results indicate that soil N2 fluxes are less dominant in this savanna than in other ecosystems investigated. © 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/83396
Appears in Collections: 气候减缓与适应 气候变化事实与影响
There are no files associated with this item.
作者单位: Department of Ecology and Evolutionary Biology, Cornell University, Ithaca, NY, United States; Cary Institute of Ecosystem Studies, Millbrook, NY, United States
Recommended Citation:
Soper F.M.,Groffman P.M.,Sparks J.P.. Denitrification in a subtropical, semi-arid North American savanna: field measurements and intact soil core incubations[J]. Biogeochemistry,2016-01-01,128(2018-01-02)