DOI: 10.1029/2019GB006298
论文题名: A Cross-System Comparison of Dark Carbon Fixation in Coastal Sediments
作者: Vasquez-Cardenas D. ; Meysman F.J.R. ; Boschker H.T.S.
刊名: Global Biogeochemical Cycles
ISSN: 0886-6236
EISSN: 1944-9224
出版年: 2020
卷: 34, 期: 2 语种: 英语
英文关键词: bioturbation
; carbon fixation
; chemoautotrophy
; continental shelf
; fatty acid
; hydrothermal vent
; microbial activity
; porewater
; saltmarsh
; seafloor
; stable isotope
; sulfur compound
; Bacteria (microorganisms)
; Beggiatoa
学科: Beggiatoa
; bioturbation
; cable bacteria
; chemoautotrophy
; fatty acids
; salt marsh
中文摘要: Dark carbon fixation (DCF) by chemoautotrophic microorganisms can sustain food webs in the seafloor by local production of organic matter independent of photosynthesis. The process has received considerable attention in deep sea systems, such as hydrothermal vents, but the regulation, depth distribution, and global importance of coastal sedimentary DCF have not been systematically investigated. Here we surveyed eight coastal sediments by means of stable isotope probing (13C-DIC) combined with bacterial biomarkers (phospholipid-derived fatty acids) and compiled additional rates from literature into a global database. DCF rates in coastal sediments range from 0.07 to 36.30 mmol C m−2 day−1, and there is a linear relation between DCF and water depth. The CO2 fixation ratio (DCF/CO2 respired) also shows a trend with water depth, decreasing from 0.09 in nearshore environments to 0.04 in continental shelf sediments. Five types of depth distributions of chemoautotrophic activity are identified based on the mode of pore water transport (advective, bioturbated, and diffusive) and the dominant pathway of microbial sulfur oxidation. Extrapolated to the global coastal ocean, we estimate a DCF rate of 0.04 to 0.06 Pg C year−1, which is less than previous estimates based on indirect measurements (0.15 Pg C year−1), but remains substantially higher than the global DCF rate at deep sea hydrothermal vents (0.001–0.002 Pg C year−1). ©2020. The Authors. Citation statistics:
资源类型: 期刊论文
标识符: http://119.78.100.158/handle/2HF3EXSE/160066
Appears in Collections: 气候变化与战略
There are no files associated with this item.
作者单位: Department of Biotechnology, Delft University of Technology, Delft, Netherlands; Department of Biology, University of Antwerp, Antwerp, Belgium
Recommended Citation:
Vasquez-Cardenas D.,Meysman F.J.R.,Boschker H.T.S.. A Cross-System Comparison of Dark Carbon Fixation in Coastal Sediments[J]. Global Biogeochemical Cycles,2020-01-01,34(2)