Carbon accumulation in peatlands, southwestern Northwest Territories, Canada

2006 ◽  
Vol 86 (Special Issue) ◽  
pp. 305-319 ◽  
Author(s):  
Stephen D. Robinson
Keyword(s):  
Northwest Territories ◽  
High Water ◽  
Decay Rates ◽  
Carbon Accumulation ◽  
Poor Fen ◽  
Discontinuous Permafrost ◽  
Highly Sensitive ◽  
Water Tables ◽  
Rate Of Decay ◽  
Northern Peatlands

Northern peatlands have stored significant quantities of carbon (C) since the early Holocene at rates that vary among peatland types. Pollen concentration dating was used to provide estimates o f true C accumulation and sequestration efficiency in different peatland systems in the discontinuous permafrost zone near Fort Simpson, Northwest Territories, Canada. The catotelm portions of bog, permafrost-affected peat plateau, and Sphagnum-dominated cores were interpreted to conform to Clymo’s (1984) model of C accumulation, while peat deposited under conditions with high water tables (rich fen and collapse fen) did not. The model assumes a consistent surface production, yet production in fens is thought to be highly sensitive to water table changes and may have contributed to poor model fits. Decay rates measured over the past 1200 yr range from 0.0015 to 0.0004 yr-1. True C accumulation rates (range 7.0 in peat plateau to 18.6 g C m-2 yr-1 in bog) and sequestration efficiencies (range 0.24 in peat plateau to 0.67 in poor fen) by 1200 yr BP were low in comparison with other North American sites. Decay rates measured over 1200 yr were significantly greater than that measured over the entire life span of the peatland (0.00033 yr-1), suggesting that a catotelm true C accumulation model incorporating a decreasing rate of decay would be more applicable. Key words: Carbon accumulation, peatlands, permafrost, northern Canada

Response of a warm temperate peatland to Holocene climate change in northeastern Pennsylvania

2011 ◽  
Vol 75 (3) ◽  
pp. 531-540 ◽  
Author(s):  
Shanshan Cai ◽  
Zicheng Yu
Keyword(s):  
Accumulation Rate ◽  
Carbon Accumulation ◽  
Temperate Climate ◽  
High Accumulation ◽  
Southern Limit ◽  
Proxy Records ◽  
Poor Fen ◽  
Northern Peatlands ◽  
Warm Temperate ◽  
Northeastern Pennsylvania

AbstractStudying boreal-type peatlands near the edge of their southern limit can provide insight into responses of boreal and sub-arctic peatlands to warmer climates. In this study, we investigated peatland history using multi-proxy records of sediment composition, plant macrofossil, pollen, and diatom analysis from a 14C-dated sediment core at Tannersville Bog in northeastern Pennsylvania, USA. Our results indicate that peat accumulation began with lake infilling of a glacial lake at ~ 9 ka as a rich fen dominated by brown mosses. It changed to a poor fen dominated by Cyperaceae (sedges) and Sphagnum (peat mosses) at ~ 1.4 ka and to a Sphagnum-dominated poor fen at ~ 200 cal yr BP (~ AD 1750). Apparent carbon accumulation rates increased from 13.4 to 101.2 g C m− 2 yr− 1 during the last 8000 yr, with a time-averaged mean of 27.3 g C m− 2 yr− 1. This relatively high accumulation rate, compared to many northern peatlands, was likely caused by high primary production associated with a warmer and wetter temperate climate. This study implies that some northern peatlands can continue to serve as carbon sinks under a warmer and wetter climate, providing a negative feedback to climate warming.

Hydrological changes in the Rzecin peatland (Puszcza Notecka, Poland) induced by anthropogenic factors: Implications for mire development and carbon sequestration

The Holocene ◽  
2016 ◽  
Vol 27 (5) ◽  
pp. 651-664 ◽  
Author(s):  
Krystyna Milecka ◽  
Grzegorz Kowalewski ◽  
Barbara Fiałkiewicz-Kozieł ◽  
Mariusz Gałka ◽  
Mariusz Lamentowicz ◽  
...  
Keyword(s):  
Carbon Sequestration ◽  
Plant Communities ◽  
Human Activity ◽  
Accumulation Rate ◽  
Carbon Accumulation ◽  
Anthropogenic Factors ◽  
Poor Fen ◽  
History Of ◽  
Carbon Accumulation Rates

Wetlands are very vulnerable ecosystems and sensitive to changes in the ground water table. For the last few thousand years, hydrological balance has also been influenced by human activity. To improve their cropping features, drainage activity and fertilizing were applied. The drainage process led to an abrupt change of environment, the replacement of plant communities and the entire ecosystem. The problem of carbon sequestration is very important nowadays. A higher accumulation rate is related to higher carbon accumulation, but the intensity of carbon sequestration depends on the type of mire, habitat, and climatic zone. The main aim of this article was an examination of the changes in poor-fen ecosystem during the last 200 years in relation to natural and anthropogenic factors, using paleoecological methods (pollen and macrofossils). The second aim was a detailed investigation of the sedimentary record to aid our understanding of carbon sequestration in the poor fen of temperate zone. This case study shows that fens in temperate zones, in comparison with boreal ones, show higher carbon accumulation rates which have been especially intensive over the last few decades. To reconstruct vegetation changes, detailed palynological and macrofossil analyses were done. A 200-year history of the mire revealed that it was influenced by human activity to much degree. However, despite the nearby settlement and building of the drainage ditch, the precious species and plant communities still occur.

Clay particle sizing by electrically-induced birefringence

Clay Minerals ◽  
1982 ◽  
Vol 17 (3) ◽  
pp. 313-325 ◽  
Author(s):  
D. M. Oakley ◽  
B. R. Jennings
Keyword(s):  
Orientational Order ◽  
Decay Rates ◽  
Sufficient Information ◽  
Electron Microscopic ◽  
Experimental Conditions ◽  
Clay Particles ◽  
Electron Microscopic Data ◽  
Rate Of Decay ◽  
Geometry Measurement ◽  
Log Normal

AbstractUnder the influence of a pulsed field, dilute clay sols become birefringent as the particles undergo orientational order. The rate of decay of the birefringence on removal of the field is characteristic of the particle geometry. Measurement of the decay rates under two specific experimental conditions provides sufficient information from which the particle-size distribution can be evaluated in terms of a two-parameter function. Experimental data are reported and analysed in terms of a log-normal distribution of particle sizes for attapulgite (rods), kaolinite (discs) and halloysite (ellipsoids) sols and compared with success to electron microscopic data. The ability of the method to determine size distributions in terms of the major dimensions of the clay particles, rather than those of the often used equivalent sphere, is highlighted.

Investigation of ligand effects on exciton recombination in PbS nanoparticles

2011 ◽  
Vol 89 (3) ◽  
pp. 339-346 ◽  
Author(s):  
Jennifer M. Zemke ◽  
Thomas E. Novet ◽  
David R. Tyler
Keyword(s):  
Transient Absorption ◽  
Decay Rates ◽  
Transient Absorption Spectroscopy ◽  
Absorption Data ◽  
Pbs Nanoparticles ◽  
Nonradiative Decay ◽  
Femtosecond Transient Absorption ◽  
Ligand Shell ◽  
Highly Sensitive ◽  
Exciton Recombination

Multiple exciton generation (MEG) and exciton recombination were studied by femtosecond transient absorption spectroscopy in PbS nanoparticles (NPs) capped with oleic acid (PbS–OLA) and 2,3-dimercaptopropane sulfonate (PbS–DMPS) ligands. Analysis of the transient absorption data showed that the PbS–DMPS nanoparticles exhibit increased rates of multi- and single-exciton recombination compared with the PbS–OLA nanoparticles; however, the MEG yield for both sets of particles was the same within experimental error. The origin of the differences in the exciton recombination decay rates is unknown, but it is speculated that it may be due to the ionic functionality of DMPS or to the different ligating atoms of the OLA and DMPS ligands. The PbS–DMPS nanoparticles were highly sensitive to the presence of oxygen, which caused a dramatic increase in nonradiative decay pathways, which can be mistaken for multiexciton absorbance and decay. Removal of oxygen eliminated the nonradiative decay pathways. Overall, this study showed that the dynamics of MEG can be modified by changing the NP ligand shell, a result that may be useful in the development of NP-based thin-film solar devices.

Engineering geology of Quaternary soils: II Methods of treatment

1991 ◽  
Vol 7 (1) ◽  
pp. 39-62 ◽  
Author(s):  
F. G. Bell
Keyword(s):  
Thermal Stabilization ◽  
High Water ◽  
Ground Freezing ◽  
Wide Range ◽  
Water Tables ◽  
Pore Water Pressures ◽  
Engineering Problems ◽  
Electro Osmosis ◽  
Introductory Paper ◽  
Methods Of Treatment

AbstractThe various soils of Quaternary age present a wide range of engineering problems such as low density, low strength, high compressibility, high permeability, collapsibility and high swell/shrink potential, as well as difficulties caused by the presence of high water tables and zones of high pore water pressures. This introductory paper describes a number of methods of ground treatment that can be used to alleviate these problems including exclusion techniques, grouting, ground freezing, drainage and groundwater lowering techniques, electro-osmosis and electro-chemical stabilization techniques, compaction and reinforcement, and methods of chemical and thermal stabilization.

Right-of-Way and Pipeline Monitoring in Permafrost: The Norman Wells Pipeline Experience

2002 ◽  
Author(s):  
Rick M. Doblanko ◽  
James M. Oswell ◽  
Alan J. Hanna
Keyword(s):  
Northwest Territories ◽  
Monitoring Program ◽  
Surveillance Program ◽  
Joint Research ◽  
Ambient Temperatures ◽  
Oil Pipeline ◽  
Right Of Way ◽  
Discontinuous Permafrost ◽  
The Government ◽  
Government Of Canada

Enbridge Pipelines (NW) Inc. (Enbridge) owns and operates a 323.9 mm outside diameter crude oil pipeline from Norman Wells, Northwest Territories, Canada to Zama, Alberta, Canada (Norman Wells Pipeline). The first of its kind in North America, this pipeline, completely buried in discontinuous permafrost, is approximately 869 kilometres in length. The pipeline, designed to operate at ambient temperatures, was constructed during the winter seasons of 1983–1984 and 1984–1985 and began operations in April 1985. Enbridge (formerly Interprovincial Pipe Line (NW) Ltd.), under various regulatory terms and conditions, is required to monitor and report the effects of pipeline construction and operations associated with the environment and right-of-way. The company has been an active participant in joint research and monitoring working groups consisting of various departments of the Government of Canada, Government of Northwest Territories, and other agencies. Over the past seventeen years, Enbridge has developed a monitoring and surveillance program that ensures the safe operation of the pipeline and protection of the environment. Any significant issues arising from the monitoring program result in mitigative actions based on engineering assessments. Furthermore, Enbridge is mandated to inform the appropriate agencies of issues resulting from the monitoring program. This paper will focus on the terrain and geotechnical monitoring programs initiated by Enbridge over its years of operation of this pipeline and will discuss topics including operations and maintenance activities key to pipelines installed in discontinuous permafrost, condition of the pipeline, and the on-going terrain and slope monitoring program.

scholarly journals Methanobacterium paludis sp. nov. and a novel strain of Methanobacterium lacus isolated from northern peatlands

2014 ◽  
Vol 64 (Pt_5) ◽  
pp. 1473-1480 ◽  
Author(s):  
Hinsby Cadillo-Quiroz ◽  
Suzanna L. Bräuer ◽  
Noah Goodson ◽  
Joseph B. Yavitt ◽  
Stephen H. Zinder
Keyword(s):  
New York ◽  
Type Species ◽  
New York State ◽  
Rrna Gene ◽  
Content Type ◽  
Link Type ◽  
Poor Fen ◽  
Low Concentrations ◽  
Ph Range ◽  
Northern Peatlands

Two mesophilic, hydrogenotrophic methanogens, designated strains SWAN1T and AL-21, were isolated from two contrasting peatlands: a near circumneutral temperate minerotrophic fen in New York State, USA, and an acidic boreal poor fen site in Alaska, USA, respectively. Cells of the two strains were rod-shaped, non-motile, stained Gram-negative and resisted lysis with 0.1 % SDS. Cell size was 0.6×1.5–2.8 µm for strain SWAN1T and 0.45–0.85×1.5–35 µm for strain AL-21. The strains used H2/CO2 but not formate or other substrates for methanogenesis, grew optimally around 32–37 °C, and their growth spanned through a slightly low to neutral pH range (4.7–7.1). Strain AL-21 grew optimally closer to neutrality at pH 6.2, whereas strain SWAN1T showed a lower optimal pH at 5.4–5.7. The two strains were sensitive to NaCl with a maximal tolerance at 160 mM for strain SWAN1T and 50 mM for strain AL-21. Na2S was toxic at very low concentrations (0.01–0.8 mM), resulting in growth inhibition above these values. The DNA G+C content of the genomes was 35.7 mol% for strain SWAN1T and 35.8 mol% for strain AL-21. Phylogenetic analysis of the 16S rRNA gene sequences showed that the strains are members of the genus Methanobacterium . Strain SWAN1T shared 94–97 % similarity with the type strains of recognized species of the genus Methanobacterium , whereas strain AL-21 shared 99 % similarity with Methanobacterium lacus 17A1T. On the basis of phenotypic, genomic and phylogenetic characteristics, strain SWAN1T ( = DSM 25820T = JCM 18151T) is proposed as the type strain of a novel species, Methanobacterium paludis sp. nov., while strain AL-21 is proposed as a second strain of Methanobacterium lacus .

Water Level Fluctuation in a Northeastern Ontario Peatland

1974 ◽  
Vol 4 (1) ◽  
pp. 76-81 ◽  
Author(s):  
T. S. Dai ◽  
V. F. Haavisto ◽  
J. H. Sparling
Keyword(s):  
Water Level ◽  
Narrow Range ◽  
Black Spruce ◽  
Heavy Rain ◽  
High Water ◽  
Water Levels ◽  
Level Fluctuation ◽  
Local Climate ◽  
Poor Fen ◽  
Run Off

Depths to water level and changes due to local climate were dissimilar in five peatland conditions in northeastern Ontario. The deepest water level and the greatest fluctuations occurred in an ombrotrophic black spruce bog site. The sedge-dominated poor fen site was submerged following every heavy rain. Waterlogged conditions remained within 6 cm of the surface at all times because of the influence by the water level of Dai Lake. The water level of Dai Lake varied within a narrow range because the loss of water was primarily dependent on slow seepage and evaporation. The lagg site was affected by continuous inflow, high water levels, and fast run-off, therefore, a larger fluctuation of water level prevailed at this site.

scholarly journals Northern peatland carbon stocks and dynamics: a review

2012 ◽  
Vol 9 (4) ◽  
pp. 5073-5107 ◽  
Author(s):  
Z. Yu
Keyword(s):  
Current Knowledge ◽  
Carbon Stocks ◽  
Carbon Accumulation ◽  
Peat Moss ◽  
Peat Accumulation ◽  
The Holocene ◽  
Sphagnum Peat Moss ◽  
Process Understanding ◽  
Net Ecosystem Carbon Balance ◽  
Northern Peatlands

Abstract. Here I review different approaches and associated uncertainties of estimates in the literature of carbon stocks and found that there is most likely 500 (± 100 range) gigatons of carbon (Gt C) in northern peatlands. The greatest uncertainty for all the approaches is the lack or insufficient representation of data, including depth, bulk density and carbon accumulation data, especially from the world's large peatlands. Several ways to improve estimates of peat carbon stocks were also discussed in this paper. Changes in peatland carbon stocks over time, estimated using Sphagnum (peat moss) spore data and down-core peat accumulation records, show different patterns during the Holocene. Considering long-term peat decomposition using peat accumulation data allows estimates of net carbon sequestration rates by peatlands, or net ecosystem carbon balance (NECB), which indicates more than half of peat carbon (> 270 Gt C) was sequestrated before 7000 yr ago during the Holocene. Contemporary carbon flux studies at 5 peatland sites show much larger NECB during the last decade (32 ± 7.8 (S.E.) g C m−2 yr−1) than during the last 7000 yr (~ 11 g C m−2 yr−1) as modeled from peat records across northern peatlands. This discrepancy highlights the urgent need for carbon accumulation data and process understanding, especially at decadal and centennial timescales, that would bridge current knowledge gaps and facilitate comparisons of NECB across all timescales.

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