DOI: 10.1007/s10533-014-9967-0
Scopus记录号: 2-s2.0-84900807088
论文题名: Anoxic microniches in marine sediments induced by aggregate settlement: Biogeochemical dynamics and implications
作者: Lehto N. ; Glud R.N. ; á Nordi G. ; Zhang H. ; Davison W.
刊名: Biogeochemistry
ISSN: 0168-2563
EISSN: 1573-515X
出版年: 2014
卷: 119, 期: 2018-01-03 起始页码: 307
结束页码: 327
语种: 英语
英文关键词: Anoxic microniches
; Denitrification
; Elemental cycling
; Marine sediments
; Marine snow
; Numerical modelling
; Planar optode
; Respiration rate
Scopus关键词: aggregate
; anoxic conditions
; denitrification
; diatom
; marine sediment
; marine snow
; numerical model
; oxygen
; reactive transport
; respiration
; sediment-water interface
; Bacillariophyta
; Skeletonema
英文摘要: Spherical (~2 mm diameter) diatom (Skeletonema sp.) aggregates, representing analogues of "marine snow", were placed at the sediment-water interface of an experimental sediment system. Optode measurements showed that, after an initial lag period, oxygen concentrations within the aggregates decreased and then were gradually replenished, resulting in a temporary anoxic microniche. A multi-species, 3-dimensional, reactive transport model was used to simulate the oxygen dynamics and the associated biogeochemical consequences. Temporal and spatial changes in oxygen were replicated assuming an exponential increase in the mineralisation rate constant and a gradual exhaustion of reactive organic material. The peak value of the time-dependent reaction rate constant of organic matter mineralisation (k OMM) was seven to sixty times greater than analogous values measured previously in water column experiments. The validated model was used to investigate how the size and reactivity of parcels of organic matter influence the formation of anoxic microniches at the sediment-water interface of typical deep-sea environments. As well as k OMM, the concentration of reactive organic matter in the aggregate, its size and porosity were also critical in determining the likelihood of anoxic microniche formation. For the optimum fitted parameters describing k OMM and the concentration of reactive organic matter, the minimum diameter of the parcel to induce anoxia was 1.8 mm, whereas it was 2.8 mm to make a significant contribution to the denitrification occurring in a typical deep-sea sediment. This work suggests that anoxic microniches resulting from the settlement of marine aggregates may play an overlooked role for denitrification activities in deep-sea sediments. © 2014 Springer International Publishing Switzerland.
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资源类型: 期刊论文
标识符: http://119.78.100.158/handle/2HF3EXSE/83593
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: Lincoln University, Christchurch, New Zealand; Institute of Biology and Nordic Center for Earth Evolution (NordCEE), University of Southern Denmark, Odense M, Denmark; Scottish Association for Marine Science, Scottish Marine Institute, Oban, United Kingdom; Greenland Climate Research Centre, Greenland Institute of Natural Resources, Nuuk, Greenland; Arctic Research Centre, University of Aarhus, Aarhus, Denmark; Aquaculture Research Station of the Faroes, Vid Áir, Faroe Islands; Lancaster Environment Centre, Lancaster University, Lancaster, United Kingdom
Recommended Citation:
Lehto N.,Glud R.N.,á Nordi G.,et al. Anoxic microniches in marine sediments induced by aggregate settlement: Biogeochemical dynamics and implications[J]. Biogeochemistry,2014-01-01,119(2018-01-03)