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Sample records for uraniferous bog deposit

  1. The Robinson and Weatherly uraniferous pyrobitumen deposits near Placerville, San Miguel County, Colorado

    USGS Publications Warehouse

    Wilmarth, V.R.; Vickers, R.C.

    1952-01-01

    Uranium deposits that contain uraniferous pyrobitumen of possible hydrothermal origin occur at the Weatherly and Robinson properties near Placerville, San Miguel County, Colo. These deposits were mined for copper, silver, and gold more than 50 years ago and were developed for uranium in 1950.

  2. Geology and recognition criteria for uraniferous humate deposits, Grants Uranium Region, New Mexico. Final report

    SciTech Connect

    Adams, S.S.; Saucier, A.E.

    1981-01-01

    The geology of the uraniferous humate uranium deposits of the Grants Uranium Region, northwestern New Mexico, is summarized. The most important conclusions of this study are enumerated. Although the geologic characteristics of the uraniferous humate deposits of the Grants Uranium Region are obviously not common in the world, neither are they bizarre or coincidental. The source of the uranium in the deposits of the Grants Uranium Region is not known with certainty. The depositional environment of the host sediments was apparently the mid and distal portions of a wet alluvial fan system. The influence of structural control on the location and accumulation of the host sediments is now supported by considerable data. The host sediments possess numerous important characteristics which influenced the formation of uraniferous humate deposits. Ilmenite-magnetite distribution within potential host sandstones is believed to be the simplest and most useful regional alteration pattern related to this type of uranium deposit. A method is presented for organizing geologic observations into what is referred to as recognition criteria. The potential of the United States for new districts similar to the Grants Uranium Region is judged to be low based upon presently available geologic information. Continuing studies on uraniferous humate deposits are desirable in three particular areas.

  3. The Robinson and Weatherly uraniferous pyrobitumen deposits near Placerville, San Miguel County, Colorado

    USGS Publications Warehouse

    Wilmarth, V.R.; Vickers, R.C.

    1953-01-01

    Uranium deposits that contain uraniferous pyrobitumen of possible hydrothermal origin occur at the Weatherly and Robinson properties near Placerville, San Miguel County, Colo. These deposits were mined for copper, silver, and gold more than 50 years ago and were developed for uranium in 1950. The Robinson property, half a mile east of Placerville, consists of the White Spar, New Discovery Lode, and Barbara Jo claims. The rocks in this area are nearly horizontal sandstones, shales, limestones, and conglomerates of the Cutler formation of Permian age and the Dolores formation of Triassic and Jurassic (?) age. These rocks have been faulted extensively and intruded by a Tertiary (?) andesite porphyry dike. Uranium-bearing pyrobitumen associated with tennantite, tetrahedrite, galena, sphalerite, chalcopyrite, bornite, azurite, malachite, calcite, barite, and quartz occurs in a lenticular body as much as 40 feet long and 6 feet wide along a northwest-trending, steeply dipping normal fault. The uranium content of eleven samples from the uranium deposit ranges from 0.001 to 0.045 percent uranium and averages about 0.02 percent uranium. The Weatherly property, about a mile northwest of Placerville, consists of the Black King claims nos. 1, 4, and 5. The rocks in this area include the complexly faulted Cutler formation of Permian age and the Dolores formation of Triassic and Jurassic (?) age. Uranium-bearing pyrobitumen arid uranophane occur, along a northwest-trending, steeply dipping normal fault and in the sedimentary rocks on the hanging wall of the fault. Lens-shaped deposits in the fault zone are as much as 6 feet long and 2 feet wide and contain as much as 9 percent uranium; whereas channel samples across the fault zone contain from 0.001 to 0.014 percent uranium. Tetrahedrite, chalcopyrite, galena, sphalerite, fuchsite, malachite, azurite, erythrite, bornite, and molybdite in a gangue of pyrite, calcite, barite, and quartz are associated with the uraniferous material

  4. Possibilities for detailed dating of peat bog deposits

    SciTech Connect

    Punning, J.; Ilomets, M.; Koff, T. )

    1993-01-01

    Geochemical and palynological data as well as radiocarbon dating were used to study the peat bog deposits in Niinsarre bog, northeast Estonia. The aim of this study was to establish criteria for determining a detailed chronology, which is important, for example, in studying paleoevents and historical monitoring. In some cases, they can use cumulative pollen data, as well as cumulative chemical and peat bulk density data. Material was gathered for [sup 14]C dating from three parallel samples taken from cores ca. 10--20 cm apart using a Russian peat sampler. Samples for peat bulk density, palynological and chemical measurements were taken from the same cores. To measure peat bulk density, the authors used a continuous sampling method. Sampling frequency was calculated to cover layers formed over 50 yr.

  5. Atmospheric nitrogen deposition promotes carbon loss from peat bogs.

    PubMed

    Bragazza, Luca; Freeman, Chris; Jones, Timothy; Rydin, Håkan; Limpens, Juul; Fenner, Nathalie; Ellis, Tim; Gerdol, Renato; Hájek, Michal; Hájek, Tomás; Iacumin, Paola; Kutnar, Lado; Tahvanainen, Teemu; Toberman, Hannah

    2006-12-19

    Peat bogs have historically represented exceptional carbon (C) sinks because of their extremely low decomposition rates and consequent accumulation of plant remnants as peat. Among the factors favoring that peat accumulation, a major role is played by the chemical quality of plant litter itself, which is poor in nutrients and characterized by polyphenols with a strong inhibitory effect on microbial breakdown. Because bogs receive their nutrient supply solely from atmospheric deposition, the global increase of atmospheric nitrogen (N) inputs as a consequence of human activities could potentially alter the litter chemistry with important, but still unknown, effects on their C balance. Here we present data showing the decomposition rates of recently formed litter peat samples collected in nine European countries under a natural gradient of atmospheric N deposition from approximately 0.2 to 2 g.m(-2).yr(-1). We found that enhanced decomposition rates for material accumulated under higher atmospheric N supplies resulted in higher carbon dioxide (CO2) emissions and dissolved organic carbon release. The increased N availability favored microbial decomposition (i) by removing N constraints on microbial metabolism and (ii) through a chemical amelioration of litter peat quality with a positive feedback on microbial enzymatic activity. Although some uncertainty remains about whether decay-resistant Sphagnum will continue to dominate litter peat, our data indicate that, even without such changes, increased N deposition poses a serious risk to our valuable peatland C sinks.

  6. The biogeochemistry of an ombrotrophic bog: Evaluation of use as an archive of atmospheric mercury deposition

    SciTech Connect

    Benoit, J.M.; Fitzgerald, W.F.; Damman, A.W.H.

    1998-08-01

    The utility of ombrotrophic bogs as archives of atmospheric mercury deposition was assessed with an investigation in Arlberg Bog, Minnesota, US. Since the use of ombrotrophic bogs as archives depends on the immobility of deposited trace metals, the authors examined the postdepositional transport processes revealed by the solid-phase distributions of mercury and ancillary metals in this bog. They modeled metal speciation in bog pore-waters as a function of pe in order to understand metal behavior in ombrotrophic peat. Specifically, they considered the effect of water movement and resultant shifts in redox potential gradients on metal retention. The results indicate that Hg and Pb are immobile in ombrotrophic peat, so their distribution can be used to determine temporal changes in deposition. To substantiate the deposition estimates determined in this study, they emphasized the importance of confirming the validity of the dating scheme, assessing the degree of horizontal homogeneity in the accumulation record, and providing evidence for retention of Hg based on geochemical modeling. As recorded in Arlberg Bog, historic atmospheric Hg deposition increased gradually after the mid-1800s, peaked between 1950 and 1960, and may have declined thereafter. Preindustrial deposition was about 4 {micro}g/m{sup 2} year and recent deposition about 19 {micro}g/m{sup 2} year. The results of this study indicate that deposition at Arlberg Bog has been influenced by a regional and/or local-scale source.

  7. Bog bodies.

    PubMed

    Lynnerup, Niels

    2015-06-01

    In northern Europe during the Iron Age, many corpses were deposited in bogs. The cold, wet and anaerobic environment leads in many cases to the preservation of soft tissues, so that the bodies, when found and excavated several thousand years later, are remarkably intact. Since the 19th century the bog bodies have been studied using medical and natural scientific methods, and recently many bog bodies have been re-examined using especially modern, medical imaging techniques. Because of the preservation of soft tissue, especially the skin, it has been possible to determine lesions and trauma. Conversely, the preservation of bones is less good, as the mineral component has been leached out by the acidic bog. Together with water-logging of collagenous tissue, this means that if the bog body is simply left to dry out when found, as was the case pre-19th century, the bones may literally warp and shrink, leading to potential pitfalls in paleopathological diagnostics. Bog bodies have in several instances been crucial in determining the last meal, as gut contents may be preserved, and thus augment our knowledge on pre-historic diet by adding to, for example, stable isotope analyses. This article presents an overview of our knowledge about the taphomic processes as well as the methods used in bog body research. PMID:25998635

  8. Could Poor Fens BE More Sensitive than Bogs to Elevated N Deposition in the Oil Sands Region of Northern Alberta?

    NASA Astrophysics Data System (ADS)

    Wieder, R. K.; Vile, M. A.; Scott, K. D.

    2015-12-01

    Bogs and fens cover 29% of the 140,000 km2 Oil Sands Administrative Area (OSAA) in northern Alberta, a region characterized by quite low background N deposition (1-2 kg/ha/yr). However, development of the oil sands resource has led to increasing emission of nitrogen oxides, which are then returned to regional ecosystems as elevated atmospheric N deposition. Given the nutrient deficient nature of bogs and poor fens, elevated N deposition from oil sands development could potentially affect peatland ecosystem structure and function. To evaluate the ecosystem-level effects of N deposition, since 2011, we have experimentally applied N to a bog and a poor fen near Mariana Lakes, Alberta, located far enough from the OSAA to be unaffected by oil sands emissions. Treatments include simulated rainfall equivalent to N deposition of 0, 5, 10, 15, 20, and 25 kg/ha/yr, plus control plots receiving no added water (3 replicate plots per site per N treatment). Concentrations of NH4+-N, NO3- N, and DON at the top of the peatland water table did not increase with increasing N deposition, averaging 0.61, 0.09, and 1.07 mg/L, respectively, in the bog, and 0.53, 0.10, and 0.81 mg/L, respectively, in the poor fen. Ericaceous shrub abundance increased with increasing N deposition in both the bog and the poor fen, although plot-scale greenness (hand-held spectral measurement of the Normalized Difference Red Edge (NDRE) index) increased with N deposition in the poor fen, but not in the bog. Segmented regression indicated that in the poor fen, at N deposition above 14-16 kg/ha/yr, total microbial, bacterial, and fungal biomass in the top 5 cm of peat increased with N deposition, with no effect at lower N deposition. No effect of N deposition on microbial, bacterial, or fungal biomass was observed at 5-10 cm in the poor fen, or at either 0-5 or 5-10 cm in the bog. In the poor fen, microbial, bacterial, and fungal biomass increased with NDRE, but the effect was not significant in the bog

  9. Impact of catchment degree on peat properties in peat deposits of eutrophic bog

    NASA Astrophysics Data System (ADS)

    Inisheva, L. I.; Golubina, O. A.; Rodikova, A. V.; Shinkeeva, N. A.; Bubina, A. B.

    2010-05-01

    Fundamental works of many investigators show that according to the biophysical properties peat deposit (PD) is divided into 2 layers: active and inert. It is interesting to analyze the supposed changes in PD of eutrophic bog according to different data (physical, chemical and biological). The researches were carried out at two plots of one bog (points 1 and 2, positions 56° 21' NL, 84° 47' EL, Russia, Siberia). Agricultural afforestation (pine planting) was made at one of them (point 2) 60 years ago. Now this plot is absolutely identical in ground cover to 1 point, but other conditions are significantly changed. In spring bog water level is at the depth of 20cm at 2 point (at 1 point it is near water face), it lows up to 53 cm during summer time (at 1 point - up to 37 cm). According to redox conditions zone of anoxic-oxic conditions reaches meter depth at 2 points. PDs don't significantly differ in activity of ammonifiers but in activity of cellulose-lytic aerobic microflora it follows that it is more active at 2 point in PD active layer. In spite of good aeration, more favorable conditions were created also for anaerobic cellulose-fermenting microflora in PD of 2 point in comparison with 1 one. Activity analysis of denitrifying agents and microflora of other physiological groups also showed high activity of biota at the plot with afforestation amelioration. This fact was confirmed by high coefficient of mineralization. Time of drainage effect created by afforestation amelioration influenced group composition of peat organic matter which builds up PD of examined plots. According to fractional and group composition data fracture of hard-to-hydrolyze organic matters decreased during the process of microflora activating at the plot with afforestation amelioration but FA content increased. Fractional composition of nitrogen showed that content of mineral nitrogen compounds definitely increased. Thus, 60 years of surface drainage influenced composition change of peat

  10. Atmospheric Mercury Transfer to Peat Bogs Dominated by Gaseous Elemental Mercury Dry Deposition.

    PubMed

    Enrico, Maxime; Roux, Gaël Le; Marusczak, Nicolas; Heimbürger, Lars-Eric; Claustres, Adrien; Fu, Xuewu; Sun, Ruoyu; Sonke, Jeroen E

    2016-03-01

    Gaseous elemental mercury (GEM) is the dominant form of mercury in the atmosphere. Its conversion into oxidized gaseous and particulate forms is thought to drive atmospheric mercury wet deposition to terrestrial and aquatic ecosystems, where it can be subsequently transformed into toxic methylmercury. The contribution of mercury dry deposition is however largely unconstrained. Here we examine mercury mass balance and mercury stable isotope composition in a peat bog ecosystem. We find that isotope signatures of living sphagnum moss (Δ(199)Hg = -0.11 ± 0.09‰, Δ(200)Hg = 0.03 ± 0.02‰, 1σ) and recently accumulated peat (Δ(199)Hg = -0.22 ± 0.06‰, Δ(200)Hg = 0.00 ± 0.04‰, 1σ) are characteristic of GEM (Δ(199)Hg = -0.17 ± 0.07‰, Δ(200)Hg = -0.05 ± 0.02‰, 1σ), and differs from wet deposition (Δ(199)Hg = 0.73 ± 0.15‰, Δ(200)Hg = 0.21 ± 0.04‰, 1σ). Sphagnum covered during three years by transparent and opaque surfaces, which eliminate wet deposition, continue to accumulate Hg. Sphagnum Hg isotope signatures indicate accumulation to take place by GEM dry deposition, and indicate little photochemical re-emission. We estimate that atmospheric mercury deposition to the peat bog surface is dominated by GEM dry deposition (79%) rather than wet deposition (21%). Consequently, peat deposits are potential records of past atmospheric GEM concentrations and isotopic composition.

  11. Atmospheric Mercury Transfer to Peat Bogs Dominated by Gaseous Elemental Mercury Dry Deposition.

    PubMed

    Enrico, Maxime; Roux, Gaël Le; Marusczak, Nicolas; Heimbürger, Lars-Eric; Claustres, Adrien; Fu, Xuewu; Sun, Ruoyu; Sonke, Jeroen E

    2016-03-01

    Gaseous elemental mercury (GEM) is the dominant form of mercury in the atmosphere. Its conversion into oxidized gaseous and particulate forms is thought to drive atmospheric mercury wet deposition to terrestrial and aquatic ecosystems, where it can be subsequently transformed into toxic methylmercury. The contribution of mercury dry deposition is however largely unconstrained. Here we examine mercury mass balance and mercury stable isotope composition in a peat bog ecosystem. We find that isotope signatures of living sphagnum moss (Δ(199)Hg = -0.11 ± 0.09‰, Δ(200)Hg = 0.03 ± 0.02‰, 1σ) and recently accumulated peat (Δ(199)Hg = -0.22 ± 0.06‰, Δ(200)Hg = 0.00 ± 0.04‰, 1σ) are characteristic of GEM (Δ(199)Hg = -0.17 ± 0.07‰, Δ(200)Hg = -0.05 ± 0.02‰, 1σ), and differs from wet deposition (Δ(199)Hg = 0.73 ± 0.15‰, Δ(200)Hg = 0.21 ± 0.04‰, 1σ). Sphagnum covered during three years by transparent and opaque surfaces, which eliminate wet deposition, continue to accumulate Hg. Sphagnum Hg isotope signatures indicate accumulation to take place by GEM dry deposition, and indicate little photochemical re-emission. We estimate that atmospheric mercury deposition to the peat bog surface is dominated by GEM dry deposition (79%) rather than wet deposition (21%). Consequently, peat deposits are potential records of past atmospheric GEM concentrations and isotopic composition. PMID:26849121

  12. Biological N2-Fixation Increases with Peatland Age and Decreases with N Deposition in Bogs of Western Canada

    NASA Astrophysics Data System (ADS)

    Fillingim, H.; Popma, J. M.; Dynarski, K. A.; Wieder, R.; Vile, M. A.

    2013-12-01

    Most terrestrial ecosystems are thought be limited primarily by nitrogen, including boreal peatlands located in pristine regions. Bogs receive nutrients solely from atmospheric deposition. Because of the historically low rates of atmospheric nitrogen deposition in Alberta, Canada, the Sphagnum mosses that dominate bog ground cover in this region have formed relationships with diazotrophs in order to meet their nitrogen needs, making biological N2- fixation the dominant input of new nitrogen to these bogs. The process of N2-fixation is highly variable and is governed by a number of environmental factors. In Alberta, one factor is water availability, as these bogs occur in some of the driest climates in which peatlands are known to exist. More recent factors with the potential to greatly alter N2-fixation dynamics include increasing nitrogen deposition associated with the growing oil sands mining operations and wildfires increasing in frequency and severity with global climate change. To determine the potential importance of N2-fixation to the overall peatland nitrogen balance under current and future conditions, we incubated the moss Sphagnum fuscum, using the acetylene reduction assay calibrated with 15N2, from 3 bogs representing ages of 3, 13, and 30 years since fire. Each bog was fertilized 8 times throughout the growing season with 0, 10, and 20 kg N/ha/yr. N2-fixation rates were measured 5 times at each site throughout the summer of 2013 to account for variation due to season and weather. Mean rates of N2-fixation increased with bog age, with higher rates in the 30 year old bog (36.90 × 8.38) and subsequently lower rates in the 13 yr (25.08 × 5.63) and 3 yr (11.58 × 6.33) old bogs. As expected, we saw decreasing rates of N2-fixation in the 10 (16.96 × 5.39) and 20 kg N/ha/yr treatments (3.35 × 1.34), as compared to water-only controls (47.62 × 12.18). These results indicate that N2-fixation supplies abundant N to support net primary productivity for bogs

  13. Peat bog records of dust deposition over the last 2000 years in the Dolomites (NE Italian Alps)

    NASA Astrophysics Data System (ADS)

    Poto, Luisa; Segnana, Michela; Gabrieli, Jacopo; Zaccone, Claudio; Barbante, Carlo

    2016-04-01

    The reconstruction of dust composition and fluxes is crucial to help to understand climate variability and climate changes. Dust fluctuations, linked to changes in dry and wet depositions, can indicate more humid or arid conditions, changes in temperature, vegetation cover and wind regimes. Peatlands are unique terrestrial archives that can capture changes in atmospheric deposition over time. Among them, ombrotrophic environments are hydrologically isolated from the surrounding landscapes receiving all the nutrients from precipitation and wind, with no influence from streams and groundwater. In recent decades biological and chemical proxies from peat bogs were extensively used to trace past climate changes, and rare earth elements (REE) in particular have been developed as inorganic geochemical proxies of mineral dust input in the atmosphere that plays an important role in the marine and terrestrial biogeochemical cycle as source for both major and trace elements. Dust deposition in the Italian Alps during the last 2000 years is estimated from the geochemical signature of two ombrotrophic peatlands. The first bog is located in Danta di Cadore (Belluno province, 1400 m a.s.l.), the second one in Coltrondo (Belluno province, 1800 m a.s.l.): they both allow us to have new insights into climate variability in the Eastern sector of the Italian Alps. The REE and the lithogenic elements concentration, as well as the lead isotopic composition were determined by CRC-ICP-QMS along the first meter of each core. For both the archives chronology is based upon independent 14C and 210Pb measurements. Changes in REE concentration through the bogs were related with those of lithogenic elements in order to test the immobility of the REE. Moreover peat humification degree was used to evaluate the hydroclimatic conditions of the bogs and Pb isotopic signature were used to trace dust deposited at Danta di Cadore and Coltrondo bogs and to discriminate natural from anthropogenic source

  14. Mercury deposition in ombrotrophic bogs in New Brunswick, Nova Scotia and Prince Edward Island. Atlantic region surveillance report number EPS-5-AR-98-4

    SciTech Connect

    Rutherford, L.A.; Matthews, S.L.

    1998-12-31

    A study was conducted to determine historical atmospheric mercury deposition patterns in the Maritime Provinces. Investigators measured mercury concentrations in peat cores from five ombrotrophic bogs in Kejimkujik, Fundy, Kouchibougouac, and Cape Breton Highlands national parks and in East Baltic Bog, Prince Edward Island. Results presented and discussed include deposition rates calculated using lead-210 date estimates, temporal trends in mercury concentrations, and spatial patterns of mercury deposition.

  15. A new approach for quantifying cumulative, anthropogenic, atmospheric lead deposition using peat cores from bogs: Pb in eight Swiss peat bog profiles.

    PubMed

    Shotyk, W; Blaser, P; Grünig, A; Cheburkin, A K

    2000-04-17

    Peat cores taken from eight Swiss peatlands were used to calculate inventories of anthropogenic Pb using either Sc or Zr to quantify Pb derived from rock weathering. The shapes of the Pb/Sc and Pb/Zr profiles suggest that Pb was supplied exclusively by atmospheric deposition at all sites. At one of the sites (Etang de la Gruère), anthropogenic Pb was calculated using both Sc and Zr as the conservative reference element. Lithogenic Pb determined using Sc was twice that obtained using Zr, possibly because Zr resides only in zircons which are dense compared to pyroxene and amphibole which are the main Sc-bearing phases in the earth's crust. However, the inventory of 'natural' Pb (supplied almost entirely by soil dust) is dwarfed by the anthropogenic inventory such that anthropogenic Pb calculated using Sc and Zr agree to within 5%. The total amount of anthropogenic Pb accumulated in the bogs was calculated by simply adding the mass of anthropogenic Pb for each peat slice over the length of each core. Cumulative, anthropogenic Pb calculated in this way ranged from 1.0 to 9.7 g/m2 and showed pronounced regional differences: the site south of the Alps (Gola di Lago in Canton Ticino) with direct exposure to the heavily industrialized region of northern Italy received nearly 10 times more anthropogenic Pb as the sites in more remote alpine regions (Schöpfenwaldmoor in Canton Berne, and Mauntschas in Canton Grisons). The approach used here to calculate cumulative, anthropogenic, atmospheric Pb (CAAPb) is simple and robust, independent of the chronology of Pb deposition, and makes no assumptions about the immobility of Pb within the peat profile. Given the worldwide distribution of peat bogs, it should be possible to undertake continental and global inventories of atmospheric metal deposition, for both the natural and anthropogenic components of most trace metals of environmental interest.

  16. Small scale controls of greenhouse gas release under elevated N deposition rates in a restoring peat bog in NW Germany

    NASA Astrophysics Data System (ADS)

    Glatzel, S.; Forbrich, I.; Krüger, C.; Lemke, S.; Gerold, G.

    2008-06-01

    In Central Europe, most bogs have a history of drainage and many of them are currently being restored. Success of restoration as well as greenhouse gas exchange of these bogs is influenced by environmental stress factors as drought and atmospheric nitrogen deposition. We determined the methane and nitrous oxide exchange of sites in the strongly decomposed center and less decomposed edge of the Pietzmoor bog in NW Germany in 2004. Also, we examined the methane and nitrous oxide exchange of mesocosms from the center and edge before, during, and following a drainage experiment as well as carbon dioxide release from disturbed unfertilized and nitrogen fertilized surface peat. In the field, methane fluxes ranged from 0 to 3.8 mg m-2 h-1 and were highest from hollows. Field nitrous oxide fluxes ranged from 0 to 574 μg m-2 h-1 and were elevated at the edge. A large Eriophorum vaginatum tussock showed decreasing nitrous oxide release as the season progressed. Drainage of mesocosms decreased methane release to 0, even during rewetting. There was a tendency for a decrease of nitrous oxide release during drainage and for an increase in nitrous oxide release during rewetting. Nitrogen fertilization did not increase decomposition of surface peat. Our examinations suggest a competition between vascular vegetation and denitrifiers for excess nitrogen. We also provide evidence that the von Post humification index can be used to explain nitrous oxide release from bogs, if the role of vascular vegetation is also considered. An assessment of the greenhouse gas release from nitrogen saturated restoring bogs needs to take into account elevated release from fresh Sphagnum peat as well as from sedges growing on decomposed peat. Given the high atmospheric nitrogen deposition, restoration will not be able to achieve an oligotrophic ecosystem in the short term.

  17. Recent atmospheric dust deposition in an ombrotrophic peat bog in Great Hinggan Mountain, Northeast China.

    PubMed

    Bao, Kunshan; Xing, Wei; Yu, Xiaofei; Zhao, Hongmei; McLaughlin, Neil; Lu, Xianguo; Wang, Guoping

    2012-08-01

    Recent deposition of atmospheric soil dust (ASD) was studied using (210)Pb-dated Sphagnum-derived peat sequences from Great Hinggan Mountain in northeast China. Physicochemical indices of peat including dry bulk density, water content, ash content, total organic carbon and mass magnetic susceptibility were measured. Acid-insoluble concentration of lithogenic metals (Al, Ca, Fe, Mn, V and Ti) were measured using ICP-AES. The basic physicochemical properties were used to assess the peat trophic status and indicated that the sections above 45-60 cm are rain-fed peat. A continuous record of ASD fluxes over the past 150 years was reconstructed based on the geochemical data obtained from the ombrotrophic zone, and the average input rate of ASD is 13.4-68.1 g m(-2) year(-1). The source of soil dust deposited in peat was dominated by the long-range transport of mineral aerosol from the drylands in north China and Mongolia. The temporal variation of ASD fluxes in the last 60 years coincides well with the meteorological records of dust storm frequency during 1954-2002 in north China. This suggests that the reconstructed sequence of atmospheric dust deposition is reliable and we can look back in time at the dust evolution before 1949. Dust storm events were observed occasionally in the late Qing dynasty, and their frequency and intensity were smaller than dust weather occurring in recent times. Four peaks of ASD fluxes were distinguished and correlated with the historical events at that time. This study presents the first atmospheric soil dust data in peat records in northeast China, and complements a global database of peat bog archives of atmospheric deposition. The results reflect the patterns of local environmental change over the past century in north China and will be helpful in formulating policies to achieve sustainable and healthy development.

  18. Recent atmospheric dust deposition in an ombrotrophic peat bog in Great Hinggan Mountain, Northeast China.

    PubMed

    Bao, Kunshan; Xing, Wei; Yu, Xiaofei; Zhao, Hongmei; McLaughlin, Neil; Lu, Xianguo; Wang, Guoping

    2012-08-01

    Recent deposition of atmospheric soil dust (ASD) was studied using (210)Pb-dated Sphagnum-derived peat sequences from Great Hinggan Mountain in northeast China. Physicochemical indices of peat including dry bulk density, water content, ash content, total organic carbon and mass magnetic susceptibility were measured. Acid-insoluble concentration of lithogenic metals (Al, Ca, Fe, Mn, V and Ti) were measured using ICP-AES. The basic physicochemical properties were used to assess the peat trophic status and indicated that the sections above 45-60 cm are rain-fed peat. A continuous record of ASD fluxes over the past 150 years was reconstructed based on the geochemical data obtained from the ombrotrophic zone, and the average input rate of ASD is 13.4-68.1 g m(-2) year(-1). The source of soil dust deposited in peat was dominated by the long-range transport of mineral aerosol from the drylands in north China and Mongolia. The temporal variation of ASD fluxes in the last 60 years coincides well with the meteorological records of dust storm frequency during 1954-2002 in north China. This suggests that the reconstructed sequence of atmospheric dust deposition is reliable and we can look back in time at the dust evolution before 1949. Dust storm events were observed occasionally in the late Qing dynasty, and their frequency and intensity were smaller than dust weather occurring in recent times. Four peaks of ASD fluxes were distinguished and correlated with the historical events at that time. This study presents the first atmospheric soil dust data in peat records in northeast China, and complements a global database of peat bog archives of atmospheric deposition. The results reflect the patterns of local environmental change over the past century in north China and will be helpful in formulating policies to achieve sustainable and healthy development. PMID:22664536

  19. Elevated Nitrogen Deposition Enhances the Net CO2 Sink Strength in Alberta Bogs along a Post-fire Chronosequence

    NASA Astrophysics Data System (ADS)

    Wieder, R. K.; Vile, M. A.; Albright, C. M.; Scott, K. D.

    2014-12-01

    About 30% of the landscape of northern Alberta, Canada is occupied by peatlands, which persist at the low end range of both mean annual precipitation (<500 mm/yr) and mean annual atmospheric nitrogen (N) deposition (< 1 kg/ha/yr) across which peatlands are found globally. Ombrotrophic bogs in this region function as a net sink for atmospheric CO2 of over 75 g/m2/yr, taking into consideration changes in CO2 sink strength as a function of time since fire. In addition to fire, a new disturbance is emerging in the Athabasca Oil Sands Region (AOSR) of northern Alberta, where development of the oil sands resource has increased atmospheric N deposition to as much as 2.5 kg/ha/yr. To examine the effects of elevated N deposition on bog C cycling, we experimentally applied N (as NH4NO3 solutions) to replicated plots at levels equivalent to 0 (water added with no N), 10, and 20 kg/ha/yr, and controls (no waher, no N added) at five bog sites, aged at 2, 12, 32, 73, and 113 years since fire in 2013 (6 plots per N treatment per site). Understory net ecosystem exchange of CO2 (NEE) was measured repeatedly throughout the 2013 and 2014 growing season (and in 2011 and 2012 at the most recently burned site) using the closed chamber approach. Using a rectangular hyperbola equation to characterize NEE as a function of photosynthetically active radiation (PAR) and near-surface air temperature (T), monthly and annual NEE was estimated based on hourly measurements of PAR and T at each site. Across all sites, a general pattern emerged that N additions enhanced the net CO2 sink strength of the bogs, with no effect on ecosystem respiration. Net primary production of Sphagnum fuscum, the dominant peat-forming moss, was not affected by N addition, suggesting that the overall response of NEE to N addition is the result of enhanced growth of ericaceous shrubs. These findings suggest that while elevated N deposition in the AOSR may enhance the strength of the overall CO2 sink of bogs in the short

  20. Ombrotrophic peat bogs are not suited as natural archives to investigate the historical atmospheric deposition of perfluoroalkyl substances.

    PubMed

    Dreyer, Annekatrin; Thuens, Sabine; Kirchgeorg, Torben; Radke, Michael

    2012-07-17

    As ombrotrophic peat bogs receive only atmospheric input of contaminants, they have been identified as suitable natural archives for investigating historical depositions of airborne pollutants. To elucidate their suitability for determining the historical atmospheric contamination with perfluoroalkyl substances (PFAS), two peat cores were sampled at Mer Bleue, a bog located close to Ottawa, Canada. Peat cores were segmented, dried, and analyzed in duplicate for 25 PFASs (5 perfluororalkyl sulfonates (PFSAs), 13 perfluoroalkyl carboxylates (PFCAs), 7 perfluororalkyl sulfonamido substances). Peat samples were extracted by ultrasonication, cleaned up using a QuEChERS method, and PFASs were measured by HPLC-MS/MS. Twelve PFCAs and PFSAs were detected regularly in peat samples with perfluorooctane sulfonate (85-655 ng kg(-1)), perfluorooctanoate (150-390 ng kg(-1)), and perfluorononanoate (45-320 ng kg(-1)) at highest concentrations. Because of post depositional relocation processes within the peat cores, true or unbiased deposition fluxes (i.e., not affected by post depositional changes) could not be calculated. Apparent or biased deposition rates (i.e., affected by post depositional changes) were lower than measured/calculated deposition rates for similar urban or near-urban sites. Compared to PFAS production, PFAS concentration and deposition maxima were shifted about 30 years toward the past and some analytes were detected even in the oldest segments from the beginning of the 20th century. This was attributed to PFAS mobility in the peat profile. Considerable differences were observed between both peat cores and different PFASs. Overall, this study demonstrates that ombrotrophic bogs are not suited natural archives to provide authentic and reliable temporal trend data of historical atmospheric PFAS deposition.

  1. Mercury in a spanish peat bog: archive of climate change and atmospheric metal deposition

    PubMed

    Martinez-Cortizas; Pontevedra-Pombal; Garcia-Rodeja; Novoa-Munoz; Shotyk

    1999-05-01

    A peat core from a bog in northwest Spain provides a record of the net accumulation of atmospheric mercury since 4000 radiocarbon years before the present. It was found that cold climates promoted an enhanced accumulation and the preservation of mercury with low thermal stability, and warm climates were characterized by a lower accumulation and the predominance of mercury with moderate to high thermal stability. This record can be separated into natural and anthropogenic components. The substantial anthropogenic mercury component began approximately 2500 radiocarbon years before the present, which is near the time of the onset of mercury mining in Spain. Anthropogenic mercury has dominated the deposition record since the Islamic period (8th to 11th centuries A.D.). The results shown here have implications for the global mercury cycle and also imply that the thermal lability of the accumulated mercury can be used not only to quantify the effects of human activity, but also as a new tool for quantitative paleotemperature reconstruction. PMID:10320369

  2. Reconstructing historical atmospheric mercury deposition in Western Europe using: Misten peat bog cores, Belgium.

    PubMed

    Allan, Mohammed; Le Roux, Gael; Sonke, Jeroen E; Piotrowska, Natalia; Streel, Maurice; Fagel, Nathalie

    2013-01-01

    Four sediment cores were collected in 2008 from the Misten ombrotrophic peat bog in the Northern part of the Hautes Fagnes Plateau in Belgium. Total mercury (Hg) concentrations were analyzed to investigate the intra-site variability in atmospheric Hg deposition over the past 1,500 years. Mercury concentrations in the four cores ranged from 16 to 1,100 μg kg(-1), with the maxima between 840 and 1,100 μg kg(-1). A chronological framework was established using radiometric (210)Pb and (14)C dating of two cores (M1 and M4). Pollen horizons from these two cores were correlated with data from two additional cores, providing a consistent dating framework between all the sites. There was good agreement between atmospheric Hg accumulation rates in the four cores over time based on precise age dating and pollen chronosequences. The average Hg accumulation rate before the influence of human activities (from 500 to 1,300 AD) was 1.8 ± 1 μg m(-2)y(-1) (2SD). Maximum Hg accumulation rates ranged from 90 to 200 μg m(-2)y(-1) between 1930 and 1980 AD. During the European-North American Industrial Revolution, the mean Hg accumulation rate exceeded the pre-Industrial values by a factor of 63. Based on comparisons with historical records of anthropogenic activities in Europe and Belgium, the predominant regional anthropogenic sources of Hg during and after the Industrial Revolution were coal burning and smelter Hg emissions. Mercury accumulation rates and chronologies in the Misten cores were consistent with those reported for other European peat records.

  3. Determination of atmospheric nitrogen deposition to a semi-natural peat bog site in an intensively managed agricultural landscape

    NASA Astrophysics Data System (ADS)

    Hurkuck, Miriam; Brümmer, Christian; Mohr, Karsten; Grünhage, Ludger; Flessa, Heinz; Kutsch, Werner L.

    2014-11-01

    Rising levels of atmospheric nitrogen (N) deposition have been found to affect the primary productivity and species composition of most terrestrial ecosystems. Highly vulnerable ecosystems such as nutrient-poor bogs are expected to respond to increasing N input rates with a decrease in plant species diversity. Our study site - a moderately drained raised bog and one of only very few remaining protected peatland areas in Northwestern Germany - is surrounded by highly fertilised agricultural land and intensive livestock production. We quantified the annual deposition of atmospheric N over a period of two years. Dry deposition rates of different N species and their reactants were calculated from day and night-time concentrations measured by a KAPS denuder filter system. Dry N deposition amounted to 10.9 ± 1.0 kg N ha-1 yr-1 (year 1) and 10.5 ± 1.0 kg N ha-1 yr-1 (year 2). More than 80% of total deposited N was attributed to ammonia (NH3). A strong seasonality in NH3 concentrations and depositions could be observed. Day and night-time concentrations and depositions, however, did not differ significantly. Total N deposition including bulk N deposition resulted in about 25 kg N ha-1 yr-1. Our results suggest that the intensive agricultural land management of surrounding areas and strongly emitting animal husbandry lead to N inputs into the protected peatland area that exceed the ecosystem's specific critical load up to fivefold. This gives rise to the assumption that a further shift in plant species composition with a subsequent alteration of the local hydrological regime can be expected.

  4. Retention of As and Sb in ombrotrophic peat bogs: records of As, Sb, and Pb deposition at four Scottish sites

    SciTech Connect

    Joanna M. Cloy; John G. Farmer; Margaret C. Graham; Angus B. MacKenzie

    2009-03-15

    Possible postdepositional As migration in ombrotrophic peat bogs was investigated by comparing depth profiles of As with those of Sb and Pb, two elements considered to be essentially immobile in peat, and those of redox-sensitive, potentially mobile nutrient elements such as Mn, Fe, P, and S in {sup 210}Pb-dated cores from four Scottish bogs. Concentration profiles of As were similar to those of Sb and Pb rather than these other elements, indicating that As is bound strongly to organic matter and is relatively immobile in ombrotrophic peat. Historical records of atmospheric anthropogenic As, Sb, and Pb deposition during the industrial and postindustrial periods were derived, site-specific maxima (up to 1.55, 1.33, and 45 mg m{sup -2} y{sup -1}, respectively) occurring between the late 1890s and 1960s, reflecting emissions from diverse sources such as mining and smelting, coal combustion, and also, in the case of Pb, exhaust emissions from the use of leaded gasoline. Since the mid-1980s, fluxes of Pb decreased (4-7 fold) more rapidly than those of As and Sb (2-3 fold), attributable to both the gradual elimination of leaded gasoline and recent new sources of the latter elements. Relative trends in derived anthropogenic As, Sb, and Pb deposition largely agreed with other Scottish peat and moss archive records, direct measurements of deposition, and UK emissions, i.e., four different types of data source. 36 refs., 3 figs., 1 tab.

  5. Retention of As and Sb in ombrotrophic peat bogs: records of As, Sb, and Pb deposition at four Scottish sites.

    PubMed

    Cloy, Joanna M; Farmer, John G; Graham, Margaret C; MacKenzie, Angus B

    2009-03-15

    Possible postdepositional As migration in ombrotrophic peat bogs was investigated by comparing depth profiles of As with those of Sb and Pb, two elements considered to be essentially immobile in peat, and those of redox-sensitive, potentially mobile nutrient elements such as Mn, Fe, P, and S in 210Pb-dated cores from four Scottish bogs. Concentration profiles of As were similar to those of Sb and Pb rather than these other elements, indicating that As is bound strongly to organic matter and is relatively immobile in ombrotrophic peat. Historical records of atmospheric anthropogenic As, Sb, and Pb deposition during the industrial and postindustrial periods were derived, site-specific maxima (up to 1.55, 1.33, and 45 mg m(-2) y(-1), respectively) occurring between the late 1890s and 1960s, reflecting emissions from diverse sources such as mining and smelting, coal combustion, and also, in the case of Pb, exhaust emissions from the use of leaded gasoline. Since the mid-1980s, fluxes of Pb decreased (4-7 fold) more rapidly than those of As and Sb (2-3 fold), attributable to both the gradual elimination of leaded gasoline and recent new sources of the latter elements. Relative trends in derived anthropogenic As, Sb, and Pb deposition largely agreed with other Scottish peat and moss archive records, direct measurements of deposition, and UK emissions, i.e., four different types of data source. PMID:19368168

  6. Holocene tephra horizons at Klocka Bog, west-central Sweden: aspects of reproducibility in subarctic peat deposits

    NASA Astrophysics Data System (ADS)

    Bergman, Jonas; Wastegård, Stefan; Hammarlund, Dan; Wohlfarth, Barbara; Roberts, Stephen J.

    2004-03-01

    This paper presents one of the most extensive Holocene tephra records found to date in Scandinavia. Microtephra horizons originating from Icelandic eruptions were recorded in two ca. 2 m thick peat profiles at Klocka Bog in west-central Sweden. Five of the microtephra horizons were geochemically correlated to the Askja-1875, Hekla-3, Kebister, Hekla-4 and Lairg A tephras respectively. Radiocarbon-based dating of these tephras broadly agree with previously published ages from Iceland, Sweden, Germany and the British Isles. The identification of the Lairg A tephra demonstrates a more widespread distribution than previously thought, extending the usefulness of Icelandic Holocene tephrochronology further north into west-central Scandinavia. Long-lasting snow cover and seasonal wind distribution in the lower stratosphere are suggested as factors that may be responsible for fragmentary tephra deposition patterns in peat deposits of subarctic Scandinavia. Copyright

  7. Geochemical Evidence for Periods of Increased Mineral Dust Deposition in Patagonian Peat Bogs Since the Last Deglaciation

    NASA Astrophysics Data System (ADS)

    Vanneste, H.; De Vleeschouwer, F.; Mattielli, N. D.; Vanderstraeten, A.; von Scheffer, C.; Piotrowska, N.; Coronato, A.; Le Roux, G.

    2013-12-01

    Atmospheric mineral dust plays an important role in the earth's climate system, influencing atmospheric parameters such as cloud condensation as well as biogeochemical cycles, affecting atmospheric CO2 levels. Antarctic ice core records show that mineral dust deposition has varied in the Southern Hemisphere over glacial-interglacial stages, suggesting major changes in atmospheric circulation. Nevertheless, to make predictions for the near future possible, a better understanding of atmospheric dust load and transport variability in the recent past, is essential. Ombrotrophic peat bogs have proven to provide excellent records of atmospheric dust deposition for the Holocene as their accumulation rates are higher than any other archive. Hence two ombrotrophic peat bogs, located southwest (Karukinka) and southeast (Harberton) on Isla Grande de Tierra del Fuego, were sampled to investigate dust-palaeoclimatic interactions in southern South America since the last deglaciation. Here we present a detailed geochemical (major, trace elements and Nd isotopes) record for both sites. The base of the peat sequences in Karukinka and Harberton were dated by 14C at ca. 8,000 cal yr BP and ca. 16,500 cal yr BP, respectively. The distribution of trace elemental (Sc, REE) concentrations within the cores indicates, besides tephra layers, episodes of increased mineral dust deposition at Harberton and Karukinka. The glacial-interglacial transition can be observed in the Harberton record (at ca. 11,500 cal yr BP), marked by a drop in the dust flux from 102 g/m2/yr to 10 g/m2/yr. The most significant episode of mineral dust deposition at Karukinka is concentrated around 1,600 cal yr BP with a maximum dust flux of 108 g/m2/yr. Its neodymium isotopic signature of -1 suggests crustal admixing, compared to the ɛNd values of ˜2, for both tephra layers.

  8. Atmospheric Pb deposition in Spain during the last 4600 years recorded by two ombrotrophic peat bogs and implications for the use of peat as archive.

    PubMed

    Martinez Cortiza, A; García-Rodeja, E; Pontevedra Pombal, X; Nóvoa Muñoz, J C; Weiss, D; Cheburkin, A

    2002-06-20

    Two ombrotrophic peat bogs in Northwestern Spain provided a history of 4600 years of Pb accumulation. Highest Pb concentrations (84-87 microg g(-1)) were found near the bogs' surface, but there were also other significant peaks (6-14 microg g(-1)), indicating pre-industrial atmospheric pollution. The enrichment factors (EFs) in both cores show a remarkably similar record. Atmospheric Pb pollution dates back to at least approximately 2500 years ago, reaching a first maximum during the Roman period. For the last 300 years, Pb EFs significantly increased due to industrial development, but the uppermost samples of the bogs show decreasing Pb EFs, probably due to the phasing out of leaded gasoline. These results are also supported by 206Pb/207Pb isotope ratios, as they continuously decrease from ca. 3000 BP until 2000 BP (from 1.275 at 4070 14C years BP to 1.182), indicating the growing importance of nonradiogenic Pb released from Iberian ores by ancient mining. Peat samples at a 3-5-cm depth are even less radiogenic (206Pb/107Pb = 1.157), indicating the strong influence of leaded gasoline. Despite the common history shared by the two bogs, striking differences were found for Pb enrichment, whether this was calculated by normalising to the Pb/Ti ratio of the upper continental crust or to the Pb/Ti ratios of peats from pre-anthropogenic times. This effect seems to be related to differences in Ti accumulation in both bogs, possibly due to physical fractionation of the airborne dust during wind transport. Enrichment has to be carefully considered when comparing the results obtained for different bogs, since our results suggest that normalising to crustal proportions is meaningless when the bulk of the deposition in an area is strongly influenced by short- and medium-range dust transport. PMID:12108443

  9. Inputs of Nitrogen to Bogs of Alberta, Canada: the Importance of Biological Nitrogen Fixation VS. Atmospheric Deposition from Oil Sands Mining

    NASA Astrophysics Data System (ADS)

    Prsa, T.; Vile, M. A.; Wieder, R.; Vitt, D. H.

    2010-12-01

    Bogs of Alberta, Canada are peatlands that are both Sphagnum-moss dominated and nutrient limited. Due to their ombrotrophic nature, nitrogen (N) is deposited only via atmospheric deposition (wet/dry) and biological N2 fixation. Historically, bogs of Alberta are unpolluted with low rates of atmospheric N deposition (< 1 kg ha-1 yr-1), as opposed to eastern Canada and western Europe where rates are considerably higher (>15 kg ha-1 yr-1). Due to the extensive rich bitumen deposits under northern Alberta, however, the Oil Sands Mining (OSM) industry has been growing exponentially since the late 1960’s. Bogs situated near OSM, therefore, are likely to experience increased N deposition and the consequences and impacts of such a phenomenon are as yet, unknown. Additional N inputs into these N-limited ecosystems may cause an imbalance in the N-cycle, specifically, biological N2 fixation. Our goal was to quantify inputs of N to the system from both rates of biological N2 fixation and bulk atmospheric deposition. In summer 2010, we used acetylene reduction assay (ARA) to indirectly measure N2 fixation rates in the four most abundant moss species: Sphagnum fuscum, S. capillifolium, S. angustifolium and Pleurozium schreberi at three bog sites varying in proximity to OSM: McMurray, McKay and Utikuma bog (51, 24 and 300 km, respectively) throughout the growing season (May-August comprising 6 sampling efforts). We measured atmospheric N deposition with ion exchange resin columns (10 per site). An ANOVA and subsequent ad hoc test indicated that Utikuma had significantly lower atmospheric N deposition rates (0.130 ± 0.19 mg m-2 d-1; µ ± SE) than both McMurray and McKay (0.337 ± 0.03 and 0.262 ± 0.03 mg m-2 da-1, respectively; F2,24 = 9.04, p<0.0012), demonstrating that sites closest to the OSM region do exhibit higher rates of atmospheric N deposition. Alternatively, for inputs of N via N2 fixation, we found that McMurray (700.6 ± 144.7 µmol m-2 da-1) had significantly

  10. Historical records of atmospheric metal deposition along the St. Lawrence Valley (eastern Canada) based on peat bog cores

    NASA Astrophysics Data System (ADS)

    Pratte, Steve; Mucci, Alfonso; Garneau, Michelle

    2013-11-01

    The recent history of atmospheric As, Cd, Ni, Pb and Zn deposition and the stable Pb isotope signatures were reconstructed from short cores collected at three peat bogs along the St. Lawrence Valley (SLV). The onset of industrial activity was recorded around 1810-1850 AD. As, Cd, Pb and, to a certain extent, Ni deposition rates reached maxima between 1940 and the early 1970s. Trace metals likely originated from coal-burning and ore smelting between 1850 and 1950 AD, and were replaced thereafter, at least in the case of Pb, by the combustion of leaded gasolines until the mid-1980s. Trace metal contents and accumulation rates were greater in the two cores recovered from the southwestern SLV than further northeast, as expected from their proximity to urban and industrial centers of eastern Canada and the U.S. Mid-West and the direction of the prevalent winds. A rapid decrease in metal accumulation rates since the 1970s suggests that mitigation policies were effective in reducing atmospheric metal emissions. Nevertheless, metal accumulation rates and stable Pb isotope signatures have not yet returned to their pre-industrial values.

  11. Reconnaissance of Colorado Front Range bogs for uranium and other elements

    SciTech Connect

    Owen, D.E.; Schumann, R.R.; Otton, J.K.

    1987-08-01

    Alpine bogs form along spring-fed valley floors and in steam drainages restricted by moraines, slides, and beaver dams. The bogs are generally young (Holocene) and contain a few tens of centimeters to several meters of peat and organic-rich muck. Organic matter has a great affinity for cations such as uranium; the geochemical enrichment factor between the peats and uraniferous ground water can approach 10,000 to 1. Because the bog sediments are geologically young, the uranium is in gross disequilibrium and has low radioactivity, thus it is undetectable by ground and aerial gamma surveys. Communities that derive a part of their water supplies from drainages containing uraniferous bogs face a potential health threat because the uranium is loosely bound and may easily be remobilized by ground water moving through the bogs. Reconnaissance sampling of bogs was conducted in the Colorado Front Range from the South Park area to the Colorado-Wyoming state line. Several bogs have uranium concentrations of 1000-3000 ppm, but most bogs have uranium concentrations in the 10-100 ppm range. Zinc concentrations of 100-1000 ppm are found in some bogs and many other metallic elements are present in concentrations between 10 and 100 ppm. Concentrations between 100 and 1000 ppm of some of the rare earth elements (e.g., Ce, La, Nd, Yb) were found in the Cripple Creek area.

  12. Estimating the natural background atmospheric deposition rate of mercury utilizing ombrotrophic bogs in southern Sweden.

    PubMed

    Bindler, R

    2003-01-01

    A critical gap in the understanding of the global cycling of mercury is the limited data describing the natural background atmospheric deposition rate of mercury before the advent of pollution. Existing estimates of the natural deposition rate are typically about 2-5 microg of Hg m(-2) year(-1) (see, for example, Swain et al. Science 1992, 257, 784-787), based on studies that generally rely on short, 210Pb-dated lake sediment and peat cores that span the past 150 years. Analyses of mercury in long peat cores in southcentral Sweden indicate that natural mercury deposition rates in the period 4000-500 BP were lower, about 0.5-1 microg of Hg m(-2) year(-1). This suggests that recent mercury accumulation rates in the peat (15-25 microg of Hg m(-2) year(-1)) and measured atmospheric deposition rates of mercury in Sweden over the past 3 decades (5-30 microg of Hg m(-2) year(-1)) (Munthe et al. Water, Air, Soil Pollut.: Focus 2001, 1, 299-310) are at least an order of magnitude greater than the prepollution deposition rate, rather than representing only a 3-5-fold increase, as has generally been estimated.

  13. Grass species influence on plant N uptake - Determination of atmospheric N deposition to a semi-natural peat bog site using a 15N labelling approach

    NASA Astrophysics Data System (ADS)

    Hurkuck, Miriam; Brümmer, Christian; Spott, Oliver; Flessa, Heinz; Kutsch, Werner L.

    2014-05-01

    Large areas of natural peat bogs in Northwestern Germany have been converted to arable land and were subjected to draining and peat cutting in the past. The few protected peatland areas remaining are affected by high nitrogen (N) deposition. Our study site - a moderately drained raised bog - is surrounded by highly fertilized agricultural land and livestock production. In this study, we used a 15N pool dilution technique called 'Integrated Total Nitrogen Input' (ITNI) to quantify annual deposition of atmospheric N into biomonitoring pots over a two-year period. Since it considers direct N uptake by plants, it was expected to result in higher N input than conventional methods for determination of N deposition (e.g. micrometeorological approaches, bulk N samplers). Using Lolium multiflorum and Eriophorum vaginatum as monitor plants and low, medium and high levels of fertilization, we aimed to simulate increasing N deposition to planted pots and to allocate airborne N after its uptake by the soil-plant system in aboveground biomass, roots and soil. Increasing N fertilization was positively correlated with biomass production of Eriophorum vaginatum, whereas atmospheric plant N uptake decreased and highest airborne N input of 899.8 ± 67.4 µg N d-1 pot-1 was found for low N fertilization. In contrast, Lolium multiflorum showed a clear dependency of N supply on plant N uptake and was highest (688.7 ± 41.4 µg N d-1 pot-1) for highly fertilized vegetation pots. Our results suggest that grass species respond differently to increasing N input. While crop grasses such as Lolium multiflorum take up N according to N availability, species adopted to nutrient-limited conditions like Eriophorum vaginatum show N saturation effects with increasing N supply. Total airborne N input ranged from about 24 to 66 kg N ha-1 yr-1 dependent on the used indicator plant and the amount of added fertilizer. Parallel determination of atmospheric N deposition using a micrometeorological approach

  14. Recent atmospheric lead deposition recorded in an ombrotrophic peat bog of Great Hinggan Mountains, Northeast China, from 210Pb and 137Cs dating.

    PubMed

    Bao, K; Xia, W; Lu, X; Wang, G

    2010-09-01

    Radioactive markers are useful in dating lead deposition patterns from industrialization in peat archive. Peat cores were collected in an ombrotrophic peat bog in the Great Hinggan Mountains in Northeast China in September 2008 and dated using (210)Pb and (137)Cs radiometric techniques. The mosses in both cores were examined systematically for dry bulk density, water and ash content. Lead also was measured using atomic emission spectroscopy with inductively coupled plasma (ICP-AES). Both patterned peat profiles were preserved well without evident anthropogenic disturbance. Unsupported (210)Pb and (137)Cs decreased with the depth in both of the two sample cores. The (210)Pb chronologies were established using the constant rate of supply model (CRS) and are in good agreement with the (137)Cs time marker. Recent atmospheric (210)Pb flux in Great Hinggan Mountains peat bog was estimated to be 337 Bq m(-2)y(-1), which is consistent with published data for the region. Lead deposition rate in this region was also derived from these two peat cores and ranged from 24.6 to 55.8 mg m(-2)y(-1) with a range of Pb concentration of 14-262 microg g(-1). The Pb deposition patterns were consistent with increasing industrialization over the last 135-170 y, with a peak of production and coal burning in the last 50 y in Northeast China. This work presents a first estimation of atmospheric Pb deposition rate in peatlands in China and suggests an increasing trend of environmental pollution due to anthropogenic contaminants in the atmosphere. More attention should be paid to current local pollution problems, and society should take actions to seek a balance between economic development and environmental protection.

  15. Experimental nitrogen, phosphorus, and potassium deposition decreases summer soil temperatures, water contents, and soil CO2 concentrations in a northern bog

    NASA Astrophysics Data System (ADS)

    Wendel, S.; Moore, T.; Bubier, J.; Blodau, C.

    2010-08-01

    Ombrotrophic peatlands depend on airborne nitrogen (N), whose deposition has increased in the past and lead to disappearance of mosses and increased shrub biomass in fertilization experiments. The response of soil water content, temperature, and carbon gas concentrations to increased nutrient loading is poorly known and we thus determined these data at the long-term N fertilization site Mer Bleue bog, Ontario, during a two month period in summer. Soil temperatures decreased with NPK addition in shallow peat soil primarily during the daytime (t-test, p<0.05) owing to increased shading, whereas they increased in deeper peat soil (t-test, p<0.05), probably by enhanced thermal conductivity. RMANOVA suggested interactions between N and PK addition in particular soil layers and strong interactions between soil temperatures and volumetric water contents (p<0.05). Averaged over all fertilized treatments, the mean soil temperatures at 5 cm depth decreased by 1.3 °C and by 4.7 °C (standard deviation 0.9 °C) at noon. Water content was most strongly affected by within-plot spatial heterogeneity but also responded to both N and PK load according to RMANOVA (p<0.05). Overall, water content and CO2 concentrations in the near-surface peat (t-test, p<0.05) were lower with increasing N load, suggesting more rapid soil gas exchange. The results thus suggest that changes in bog ecosystem structure with N deposition have significant ramifications for physical parameters that in turn control biogeochemical processes.

  16. Experimental nitrogen, phosphorus, and potassium deposition decreases summer soil temperatures, water contents, and soil CO2 concentrations in a northern bog

    NASA Astrophysics Data System (ADS)

    Wendel, S.; Moore, T.; Bubier, J.; Blodau, C.

    2011-03-01

    Ombrotrophic peatlands depend on airborne nitrogen (N), whose deposition has increased in the past and lead to disappearance of mosses and increased shrub biomass in fertilization experiments. The response of soil water content, temperature, and carbon gas concentrations to increased nutrient loading is poorly known and we thus determined these data at the long-term N fertilization site Mer Bleue bog, Ontario, during a two month period in summer. Soil temperatures decreased with NPK addition in shallow peat soil primarily during the daytime (t-test, p < 0.05) owing to increased shading, whereas they increased in deeper peat soil (t-test, p < 0.05), probably by enhanced thermal conductivity. These effects were confirmed by RMANOVA, which also suggested an influence of volumetric water contents as co-variable on soil temperature and vice versa (p < 0.05). Averaged over all fertilized treatments, the mean soil temperatures at 5 cm depth decreased by 1.3 °C and by 4.7 °C (standard deviation 0.9 °C) at noon. Water content was most strongly affected by within-plot spatial heterogeneity but also responded to both N and PK load according to RMANOVA (p < 0.05). Overall, water content and CO2 concentrations in the near-surface peat (t-test, p < 0.05) were lower with increasing N load, suggesting more rapid soil gas exchange. The results thus suggest that changes in bog ecosystem structure with N deposition have significant ramifications for physical parameters that in turn control biogeochemical processes.

  17. Atmospheric deposition of silver and thallium since 12 370 14C years BP recorded by a Swiss peat bog profile, and comparison with lead and cadmium.

    PubMed

    Shotyk, William; Krachler, Michael

    2004-05-01

    A peat core from an ombrotrophic bog in Switzerland provides the first complete, long-term record (14 500 years) of atmospheric Ag and Tl deposition. The lack of enrichment of Ag and Tl in the basal peat layer shows that mineral dissolution in the underlying sediments has not contributed measurably to the Ag and Tl inventories in the peat column, and that Ag and Tl were supplied exclusively by atmospheric deposition. The temporal and spatial distribution of modern peaks in Ag and Tl concentrations are similar to those of Pb which is known to be immobile in peat profiles. Silver and Tl, therefore, are effectively immobile in the peat bog also, allowing an atmospheric deposition chronology to be reconstructed. Silver concentrations vary by up to 114x and Tl up to 241x. While Holocene climate change and land use history can explain the variation in metal concentrations and enrichment factors (EF) in ancient peats (i.e. pre-dating the Roman Period), anthropogenic sources have to be invoked to explain the very high EF values (up to 123 in the case of Ag and 12 in the case of Tl) in peat samples since the middle of the 19th Century. The "natural background" EF of Tl in ancient peats is remarkably close to unity, indicating a lack of significant enrichment of this element in atmospheric aerosols due to chemical weathering of crustal rocks. Silver, on the other hand, shows a pronounced enrichment from 8030 to 5230 (14)C years BP (12x compared to crustal rocks); this may be due to weathering phenomena or biological processes, both of which are driven by climate. Even compared to the natural enrichment of Ag during the mid-Holocene, however, the enrichments of Ag and Tl in modern peats from the Industrial Period are at least an order of magnitude greater. The Pb/Ag and Tl/Ag ratios show that Pb and Tl are preferentially released, compared to Ag, during smelting of argentiferous Pb ores mined during the Roman and Medieval Periods.

  18. Bog iron formation in the Nassawango Creek watershed, Maryland, USA

    USGS Publications Warehouse

    Bricker, O.P.; Newell, W.L.; Simon, N.S.; ,

    2004-01-01

    The Nassawango bog ores in the modern environment for surficial geochemical processes were studied. The formation of Nassawango bog ores was suggested to be due to inorganic oxidation when groundwater rich in ferrous iron emerges into the oxic, surficial environment. It was suggested that the process, providing a phosphorus sink, may be an unrecognized benefit for mitigating nutrient loading from agricultural lands. It is found that without the effect of iron fixing bacteria, bog deposites could not form at significant rates.

  19. Historical records of atmospheric Pb deposition in four Scottish ombrotrophic peat bogs: An isotopic comparison with other records from western Europe and Greenland - article no. GB2016

    SciTech Connect

    Cloy, J.M.; Farmer, J.G.; Graham, M.C.; MacKenzie, A.B.; Cook, G.T.

    2008-05-15

    Cores collected from ombrotrophic peat bogs in west central, east central, northeast and southwest Scotland were dated (C-14, Pb-210) and analyzed (ICP-OES, ICP-MS) to derive and compare their historical records of atmospheric anthropogenic Pb deposition over the past 2500 years. On the basis of Pb isotopic composition (e. g., Pb-206/Pb-207), clear indications of Pb contamination during the pre-Roman/Roman, post-Roman and medieval periods were attributed to the mining and smelting of Pb ores from Britain and elsewhere in Europe. Between the 17th and early 20th centuries, during the industrial period, the mining and smelting of indigenous Scottish Pb ores were the most important sources of anthropogenic Pb deposition at three of the sites. In contrast, at the most southerly site, influences from the use of both British Pb ores and imported Australian Pb ores (in more southern parts of Britain) since the late 19th century were evident. At each of the sites, Australian-Pb-influenced car exhaust emissions (from the 1930s to late 1990s), along with significant contributions from coal combustion (until the late 1960s and onset of the post industrial period), were evident. Atmospheric anthropogenic Pb deposition across Scotland was greatest (similar to 10 to 40 mg m{sup -2} a{sup -1}) between the late 1880s and late 1960s, increasing southward, declining to 0.44 to 5.7 mg m{sup 2} a{sup -1} by the early 2000s.

  20. The Vanishing Bog.

    ERIC Educational Resources Information Center

    Hanif, Muhammad

    1990-01-01

    Directions for the construction of a model bog habitat are provided including examples of plants and animals which may be suitable. Activities that use this model are suggested. Background information on the ecology and chemistry of the bog is included. (CW)

  1. Nature and origins of acidity in bogs

    SciTech Connect

    Urban, N.R.

    1987-01-01

    To elucidate the causes of acidity in bogs, all of the processes generating and consuming acidity in a small peat bog in northern Minnesota were measured. These processes include ion exchange, plant nutrient uptake, atmospheric deposition, decomposition, organic acid production, sulfate reduction, and denitrification. Organic acid production was found to be the dominant source of acidity, responsible for the low pH of bog waters and the high acidity in the outflow. Net biological uptake (NBU) is the next largest source of acidity. Ion exchange accounts for only about 40% of the NBU-acidity. Plant uptake and ion exchange are much larger sources of acidity on an annual basis, but much of this acidity is neutralized by decomposition. Sulfate reduction and denitrification are quantitatively unimportant at this site because inputs (NO/sub 3//sup -/ and SO/sub 4/=) are low. Bog water samples and peat cores from bogs across northeastern North America were analyzed to determine if geographic trends in the rates of acidity-generating and -consuming processes exist. Rates of organic acid production varied little across the transect. Higher values of NBU-acidity were observed in maritime bogs than in midcontinental bogs. The effects of transformations of sulfur and nitrogen on the hydrogen-ion cycle were examined in detail. Nitrate appears to be taken up by bryophytes and little is lost to denitrification. Alkalinity from nitrate uptake is low. In contrast, there is a dynamic cycle of oxidation and reduction of sulfur within bogs. Inorganic forms of sulfur are not important storage pools in peat; 35% of the total sulfur input is accumulated as organic S.

  2. Skeletal analysis and comparison of bog bodies from Northern European peat bogs.

    PubMed

    Pestka, Jan M; Barvencik, Florian; Beil, Frank T; Marshall, Robert P; Jopp, Eilin; Schilling, Arndt F; Bauerochse, Andreas; Fansa, Mamoun; Püschel, Klaus; Amling, Michael

    2010-04-01

    Although numerous bodies were deposited in Western European bogs in the past centuries, few were found and underwent archeological analysis. No studies comparing skeletal structure and mineralization of bog bodies from different ages have been performed to this day. Therefore, the aim of this study was to analyze and compare skeletal features and specifics of the human remains of three bog bodies from the Iron and Middle Ages found in Northern European peat bogs. Demineralization due to the acidic environment in peat bogs was comparably pronounced in all three bodies. Still, the macroscopic state of skeletal preservation was excellent. In addition to contact radiography, we used peripheral quantitative computed tomography to measure cortical bone mineral density. The conservation of skeletal three-dimensional microstructural elements was assessed by high-resolution microcomputed tomography analysis. These techniques revealed severe differences in bone mineral density and enabled us to determine handedness in all three bodies. Additionally, unique skeletal features like intravital bone lesions, immobilization osteoporosis, and Harris lines were found. A deformity of the left femoral head was observed which had the typical appearance of an advanced stage of Legg-Calve-Perthes disease. This study gives detailed insight into the skeletal microstructure and microarchitecture of 800- to 2,700-year-old bog bodies. Skeletal analysis enables us to draw conclusions not only concerning changes in the acidic environment of the bog, but also serves as a diagnostic tool to unravel life circumstances and diseases suffered by humans in the Iron and Middle Ages.

  3. Skeletal analysis and comparison of bog bodies from Northern European peat bogs

    NASA Astrophysics Data System (ADS)

    Pestka, Jan M.; Barvencik, Florian; Beil, Frank T.; Marshall, Robert P.; Jopp, Eilin; Schilling, Arndt F.; Bauerochse, Andreas; Fansa, Mamoun; Püschel, Klaus; Amling, Michael

    2010-04-01

    Although numerous bodies were deposited in Western European bogs in the past centuries, few were found and underwent archeological analysis. No studies comparing skeletal structure and mineralization of bog bodies from different ages have been performed to this day. Therefore, the aim of this study was to analyze and compare skeletal features and specifics of the human remains of three bog bodies from the Iron and Middle Ages found in Northern European peat bogs. Demineralization due to the acidic environment in peat bogs was comparably pronounced in all three bodies. Still, the macroscopic state of skeletal preservation was excellent. In addition to contact radiography, we used peripheral quantitative computed tomography to measure cortical bone mineral density. The conservation of skeletal three-dimensional microstructural elements was assessed by high-resolution microcomputed tomography analysis. These techniques revealed severe differences in bone mineral density and enabled us to determine handedness in all three bodies. Additionally, unique skeletal features like intravital bone lesions, immobilization osteoporosis, and Harris lines were found. A deformity of the left femoral head was observed which had the typical appearance of an advanced stage of Legg-Calve-Perthes disease. This study gives detailed insight into the skeletal microstructure and microarchitecture of 800- to 2,700-year-old bog bodies. Skeletal analysis enables us to draw conclusions not only concerning changes in the acidic environment of the bog, but also serves as a diagnostic tool to unravel life circumstances and diseases suffered by humans in the Iron and Middle Ages.

  4. Uraniferous opal, Virgin Valley, Nevada: conditions of formation and implications for uranium exploration

    USGS Publications Warehouse

    Zielinski, R.A.

    1982-01-01

    Uraniferous, fluorescent opal, which occurs in tuffaceous sedimentary rocks at Virgin Valley, Nevada, records the temperature and composition of uranium-rich solutions as well as the time of uranium-silica coprecipitation. Results are integrated with previous geologic and geochronologic data for the area to produce a model for uranium mobility that may be used to explore for uranium deposits in similar geologic settings. Uraniferous opal occurs as replacements of diatomite, or silicic air-fall ash layers in tuffaceous lakebeds of the Virgin Valley Formation (Miocene) of Merriam (1907). Fission-track radiography shows uranium to be homogeneously dispersed throughout the opal structure, suggesting coprecipitation of dissolved uranium and silica gel. Fluid inclusions preserved within opal replacements of diatomite have homogenization temperatures in the epithermal range and are of low salinity. Four samples of opal from one locality all have U-Pb apparent ages which suggest uraniferous opal precipitation in late Pliocene time. These ages correspond to a period of local, normal faulting, and highangle faults may have served as vertical conduits for transport of deep, thermalized ground water to shallower levels. Lateral migration of rising solutions occurred at intersections of faults with permeable strata. Silica and some uranium were dissolved from silica-rich host strata of 5-20 ppm original uranium content and reprecipitated as the solutions cooled. The model predicts that in similar geologic settings, ore-grade concentrations of uranium will occur in permeable strata that intersect high-angle faults and that contain uranium source rocks as well as efficient reductant traps for uranium. In the absence of sufficient quantities of reductant materials, uranium will be flushed from the system or will accumulate in low-grade disseminated hosts such as uraniferous opal. ?? 1982.

  5. Investigating Bogs: An Interdisciplinary Adventure.

    ERIC Educational Resources Information Center

    Pankiewicz, Philip R.; Schneider, Lois

    1995-01-01

    Presents the case for the use of bogs as ideal sites for hundreds of interdisciplinary lessons that combine chemistry, geology, various branches of biology, and wetlands archaeology. Includes general guidelines to aid in the design of interdisciplinary bog studies. (DDR)

  6. Atmospheric deposition of Pb, Cu, Ni, As, Sb, V, Cr, Co, Cd and Zn recorded in the Misten peat bog (Hautes-Fagnes, Belgium) during the Industrial Revolution

    NASA Astrophysics Data System (ADS)

    Allan, M.; Le Roux, G.; De Vleeschouwer, F.; Mattielli, N.; Fagel, N.

    2012-04-01

    A 40 cm peat core was studied from ombrotrophic bog in Western Europe (Misten bog, Hautes-Fagnes, Belgium). Trace metal and metalloid content (TM) and Pb isotopes were analysed by Q-ICP-MS and MC-ICP-MS, respectively. We focused our attention to a selected number of TM according to their specific enrichment (i.e. Pb, Cu, Ni, As, Sb, Cr, Co, V, Cd and Zn). Our aims were: 1) to investigate TM mobility; 2) to determine TM accumulation rates and 3) to link TM accumulation rates with established histories of anthropogenic atmospheric emission. According to 210Pb and 14C data the studied peat core section covered the last two centuries. The general agreement in TM concentration and flux profiles suggested that all TM (except Zn and Cd), were immobile in the Misten peat bog. The temporal increase of TM fluxes between the inception of the Industrial Revolution and the present vary by a factor of 5 to 50 according to TM. The maximum fluxes of TM were found between 1991 and 1995 AD. The coal consumption and metallurgical activities were the predominant source of pollution. The historical TM profiles in the Misten peat profile are in agreement with other European records, reflecting the influence of regional European pollution.

  7. Rare earth element and Nd isotope geochemistry of an ombrotrophic peat bog at Karukinka (Chile, 53.9° S): a palaeo-record of Holocene dust deposition in Tierra del Fuego.

    NASA Astrophysics Data System (ADS)

    Vanneste, Heleen; De Vleeschouwer, François; Vanderstraeten, Aubry; Mattielli, Nadine; Triquet, Delphine; Piotrowska, Natalia; Le Roux, Gael

    2013-04-01

    The value of ombrotrophic peat bogs as past atmospheric dust records, has been increasingly recognized over the past 10 years. Their high accumulation rates provide high resolution archives of natural atmospheric dust deposition since the Late Glacial, often missing in marine, lake and ice core records. Consequently, peat deposits can be used as a proxy for atmospheric circulation patterns and thus palaeoclimate. In the Southern Hemisphere, the climate is considered to be driven by the Southern Westerly Wind belt (SSW), as it significantly affects the Antarctic Circumpolar Current and hence atmospheric CO2 levels. Palaeo SSW belt migrations have been observed in palaeoclimate records but, reconstructions of SSW shifts and associated climatic changes are incoherent, in particular for the Holocene. As peatlands thrive in southwest Tierra del Fuego due to its high annual precipitation, a remote ombrotrophic peat bog at Karukinka (southwest on the Isla Grande de Tierra del Fuego) was sampled, to investigate the Holocene palaeoclimate in southern South America based on dust deposition records. A 4,5 m long Russian D-core was recovered and subsequently subsampled for elemental and isotope geochemistry in addition to density and radiocarbon dating measurements. Initial results show a number of layers enriched in scandium, indicating the presence of lithogenic material, i.e. dust. Rare earth element patterns indicate at least 2 different sources. The most significant dust peak occurs at the base of the core at ~7300 Cal years B.P and has a neodymium isotopic composition of 2.2, suggesting a volcanic origin.

  8. Large uraniferous springs and associated uranium minerals, Shirley Mountains, Carbon County, Wyoming -- A preliminary report

    USGS Publications Warehouse

    Love, J.D.

    1963-01-01

    Ten springs along the southeast flank of the Shirley Mountains, Carbon County, Wyoming, have water containing from 12 to 27 parts per billion uranium, have a total estimated flow of 3 million gallons of clear fresh water per day, and have a combined annual output that may be as much as 166 pounds of uranium. These springs emerge from Pennsylvanian, Permian, and Triassic rocks on the east flank of a faulted anticlinal fold. In the vicinity of several springs, metatyuyamunite occurs locally in crystalline calcite veins averaging 3 feet in width but reaching a maximum of 24 feet. The veins are as much as several hundred feet long-and cut vertically through sandstones of Pennsylvanian age overlying the Madison Limestone (Mississippian). This limestone is believed to be the source of the calcite. A 3-foot channel sample cross one calcite vein contains 0.089 percent uranium. Lesser amounts of uranium were obtained from other channel samples. Selected samples contain from 0.39 to 2.2 percent uranium and from 0.25 to 0.86 percent vanadium. Three possible sources of the uranium are: (1) Precambrian rocks, (2) Paleozoic rocks, (3) Pliocene(?) tuffaceous strata that were deposited unconformably across older .rocks in both the graphically high and low parts of the area, but were subsequently removed by erosion except for a few small remnants, one of which contains carnotite. There is apparently a close genetic relation between the uraniferous springs and uranium mineralization in the calcite veins. Data from this locality illustrate how uraniferous ground water can be used as a guide in the exploration for areas where uranium deposits may occur. Also demonstrated is the fact that significant quantities of uranium are present in water of some large flowing springs.

  9. Effects of grass species and grass growth on atmospheric nitrogen deposition to a bog ecosystem surrounded by intensive agricultural land use

    PubMed Central

    Hurkuck, Miriam; Brümmer, Christian; Mohr, Karsten; Spott, Oliver; Well, Reinhard; Flessa, Heinz; Kutsch, Werner L

    2015-01-01

    We applied a 15N dilution technique called “Integrated Total Nitrogen Input” (ITNI) to quantify annual atmospheric N input into a peatland surrounded by intensive agricultural practices over a 2-year period. Grass species and grass growth effects on atmospheric N deposition were investigated using Lolium multiflorum and Eriophorum vaginatum and different levels of added N resulting in increased biomass production. Plant biomass production was positively correlated with atmospheric N uptake (up to 102.7 mg N pot−1) when using Lolium multiflorum. In contrast, atmospheric N deposition to Eriophorum vaginatum did not show a clear dependency to produced biomass and ranged from 81.9 to 138.2 mg N pot−1. Both species revealed a relationship between atmospheric N input and total biomass N contents. Airborne N deposition varied from about 24 to 55 kg N ha−1 yr−1. Partitioning of airborne N within the monitor system differed such that most of the deposited N was found in roots of Eriophorum vaginatum while the highest share was allocated in aboveground biomass of Lolium multiflorum. Compared to other approaches determining atmospheric N deposition, ITNI showed highest airborne N input and an up to fivefold exceedance of the ecosystem-specific critical load of 5–10 kg N ha−1 yr−1. PMID:26257870

  10. Effects of grass species and grass growth on atmospheric nitrogen deposition to a bog ecosystem surrounded by intensive agricultural land use.

    PubMed

    Hurkuck, Miriam; Brümmer, Christian; Mohr, Karsten; Spott, Oliver; Well, Reinhard; Flessa, Heinz; Kutsch, Werner L

    2015-07-01

    We applied a (15)N dilution technique called "Integrated Total Nitrogen Input" (ITNI) to quantify annual atmospheric N input into a peatland surrounded by intensive agricultural practices over a 2-year period. Grass species and grass growth effects on atmospheric N deposition were investigated using Lolium multiflorum and Eriophorum vaginatum and different levels of added N resulting in increased biomass production. Plant biomass production was positively correlated with atmospheric N uptake (up to 102.7 mg N pot(-1)) when using Lolium multiflorum. In contrast, atmospheric N deposition to Eriophorum vaginatum did not show a clear dependency to produced biomass and ranged from 81.9 to 138.2 mg N pot(-1). Both species revealed a relationship between atmospheric N input and total biomass N contents. Airborne N deposition varied from about 24 to 55 kg N ha(-1) yr(-1). Partitioning of airborne N within the monitor system differed such that most of the deposited N was found in roots of Eriophorum vaginatum while the highest share was allocated in aboveground biomass of Lolium multiflorum. Compared to other approaches determining atmospheric N deposition, ITNI showed highest airborne N input and an up to fivefold exceedance of the ecosystem-specific critical load of 5-10 kg N ha(-1) yr(-1).

  11. Effects of grass species and grass growth on atmospheric nitrogen deposition to a bog ecosystem surrounded by intensive agricultural land use.

    PubMed

    Hurkuck, Miriam; Brümmer, Christian; Mohr, Karsten; Spott, Oliver; Well, Reinhard; Flessa, Heinz; Kutsch, Werner L

    2015-07-01

    We applied a (15)N dilution technique called "Integrated Total Nitrogen Input" (ITNI) to quantify annual atmospheric N input into a peatland surrounded by intensive agricultural practices over a 2-year period. Grass species and grass growth effects on atmospheric N deposition were investigated using Lolium multiflorum and Eriophorum vaginatum and different levels of added N resulting in increased biomass production. Plant biomass production was positively correlated with atmospheric N uptake (up to 102.7 mg N pot(-1)) when using Lolium multiflorum. In contrast, atmospheric N deposition to Eriophorum vaginatum did not show a clear dependency to produced biomass and ranged from 81.9 to 138.2 mg N pot(-1). Both species revealed a relationship between atmospheric N input and total biomass N contents. Airborne N deposition varied from about 24 to 55 kg N ha(-1) yr(-1). Partitioning of airborne N within the monitor system differed such that most of the deposited N was found in roots of Eriophorum vaginatum while the highest share was allocated in aboveground biomass of Lolium multiflorum. Compared to other approaches determining atmospheric N deposition, ITNI showed highest airborne N input and an up to fivefold exceedance of the ecosystem-specific critical load of 5-10 kg N ha(-1) yr(-1). PMID:26257870

  12. Managing bog environments for recreational experiences

    NASA Astrophysics Data System (ADS)

    Hammitt, William E.

    1980-09-01

    Bogs are of interest to outdoor recreationists, but little information exists concerning how recreation resource managers might manage these areas to enhance visitor benefits. This study evaluates bog visitor characteristics and experiences, visual preferences, and reasons for visiting. Implications for recreational resource management of bogs include the location and design of boardwalk trails and management of understory vegetation to meet the visual preferences and motives of bog visitors.

  13. Lead atmospheric deposition rates and isotopic trends in Asian dust during the last 9.5 kyr recorded in an ombrotrophic peat bog on the eastern Qinghai-Tibetan Plateau

    NASA Astrophysics Data System (ADS)

    Ferrat, Marion; Weiss, Dominik J.; Dong, Shuofei; Large, David J.; Spiro, Baruch; Sun, Youbin; Gallagher, Kerry

    2012-04-01

    been particularly important between 3.1-2.7 kyr BP and 1.7-0.9 kyr BP, suggesting a possible strengthening of the East Asian winter monsoon, in agreement with previous reconstructions in Asia. Based on the Pb/Sc and isotopic composition profiles we do not note any evidence for anthropogenic Pb derived from the thriving mining or smelting activities in northern and eastern China in the last few millennia, suggesting that atmospheric deposition to this region of the eastern Tibetan Plateau was dominated by natural Pb fluxes. These can serve as a true Asian "background" value against which anthropogenic impacts can be quantified. Our results confirm that the combination of radiogenic isotopes (Pb) and trace elements in peat bogs enables observational reconstructions of changes in past regional atmospheric circulation. Such records will enable more refined interpretations of marine and terrestrial palaeorecords in Asia and the Pacific and consequently provide further constraints for changes in ocean and atmospheric circulation and for the testing of palaeoclimate models of circulation patterns.

  14. Peat bogs in northern Alberta, Canada reveal decades of declining atmospheric Pb contamination

    NASA Astrophysics Data System (ADS)

    Shotyk, William; Appleby, Peter G.; Bicalho, Beatriz; Davies, Lauren; Froese, Duane; Grant-Weaver, Iain; Krachler, Michael; Magnan, Gabriel; Mullan-Boudreau, Gillian; Noernberg, Tommy; Pelletier, Rick; Shannon, Bob; Bellen, Simon; Zaccone, Claudio

    2016-09-01

    Peat cores were collected from six bogs in northern Alberta to reconstruct changes in the atmospheric deposition of Pb, a valuable tracer of human activities. In each profile, the maximum Pb enrichment is found well below the surface. Radiometric age dating using three independent approaches (14C measurements of plant macrofossils combined with the atmospheric bomb pulse curve, plus 210Pb confirmed using the fallout radionuclides 137Cs and 241Am) showed that Pb contamination has been in decline for decades. Today, the surface layers of these bogs are comparable in composition to the "cleanest" peat samples ever found in the Northern Hemisphere, from a Swiss bog ~ 6000 to 9000 years old. The lack of contemporary Pb contamination in the Alberta bogs is testimony to successful international efforts of the past decades to reduce anthropogenic emissions of this potentially toxic metal to the atmosphere.

  15. Results of reconnaissance for uraniferous coal, lignite, and carbonaceous shale in western Montana

    USGS Publications Warehouse

    Hail, William J.; Gill, James R.

    1952-01-01

    A reconnaissance search for uraniferous lignite and carbonaceous shale was made in western Montana and adjacent parts of Idaho during the summer of 1951. Particular emphasis in the examination was placed on coal and carbonaceous shale associated with volcanic rocks, as volcanic rocks in many area appear to have released uranium to circulating ground water from which it was concentrated in carbonaceous material. Twenty-two area in Montana and one area of Idaho were examine. The coal in five of these area is of Cretaceous age. The coal and carbonaceous shale in the remaining 18 area occur in Tertiary "lake-bed" deposits of Oligocene and younger age. Both the Cretaceous and Tertiary coal and carbonaceous shale are associated with contemporaneous or younger volcanic rocks and pyroclastic sequences. A sample of carbonaceous shale from the Prickly Pear Valley northeast of Helena, Montana, contained 0.013 percent uranium. A sample of carbonaceous shale from the Flint Creek Valley southwest of Drummond, Montana, contained 0.006 percent uranium. All other samples of both Cretaceous and Tertiary coal and carbonaceous shale were essentially non-radioactive. No further work is planned on the Cretaceous and Tertiary coal and carbonaceous shale in western Montana. A few localities in Idaho will be visited in the course of other work.

  16. Consequences of marginal drainage from a raised bog and understanding the hydrogeological dynamics as a basis for restoration

    NASA Astrophysics Data System (ADS)

    Regan, Shane; Johnston, Paul

    2010-05-01

    of vertical water losses in the peat profile not confined to the bog margins. Distinct zones of groundwater seepage in the marginal drains have been mapped based on hydrochemical and stable isotopic composition of the water and occur where drains have cut into permeable subsoil beneath the peat substrate and where the potentiometric surface of the regional groundwater table is below, or coincident with, the elevation at the base of the drain. Groundwater as a ‘supporting' ecological condition is usually confined to the perimeter of a raised bog, where peat and underlying clay thin towards the margin, allowing regional groundwater and peat water to converge and mix, thereby giving rise to characteristic nutrient rich ‘lagg' zone vegetation. However, in Clara Bog West it appears there is also a connection between the regional groundwater table and the high bog. Such a connection appears to be unique to Clara Bog West as a result of the prevailing geological conditions. A succession of Carboniferous Limestone to relatively permeable glacial till deposits to low permeability lacustrine clay sediment is the predominant underlying geology of the bog. However, there are areas where the glacial till protrudes through the lacustrine clay, which ordinarily isolates the high bog from underlying groundwater, thereby engendering a dependency on regional groundwater conditions. The hydrogeological data now suggest that drainage at the bog margin has created a hydraulic connection between these ‘subsoil subcrops' and the marginal drains, developed within the same subsoil, thereby lowering the regional groundwater table, steepening the hydraulic gradient and resulting in significant water loss from the main bog body. As such, understanding this hydrogeological connection is central to restoration activities that will aim to arrest subsidence and restore water levels that are indicative for ecotope development, on the high bog. Acknowledgements Clara Restoration Group: Jan

  17. Anthropogenic degradation of mountainous raised bogs. Case study of the Polish Carpathians

    NASA Astrophysics Data System (ADS)

    Lajczak, Adam

    2016-04-01

    Publications on the human impact on peat bogs pay a lot of attention to peat erosion, peat burning and changes in the physical and chemical properties of peat deposits that indicate pollution in the environment, but a more detailed analysis of current changes in the peat bog relief as a result of peat deposit extraction and drying is omitted. Compared to other areas of the world, the level of knowledge on anthropogenic changes in the relief of peat bogs in some areas of Poland may be considered advanced. This applies not only to peat bogs in northern Poland but also southern Poland, where peat bogs in the Carpathians and the Sudetes are also found. The best analyzed peat bogs in southern Poland are the raised bogs in the Orawsko-Nowotarska Basin (Western Carpathians) and in valleys in the Bieszczady Mts. (Eastern Carpathians). Both areas are impacted by deep precipitation shadow. The purpose of this paper is: (1) to assess the rate of shrinkage in the surface area of peat domes in the mentioned areas, (2) to describe the rate of growth in the surface area of older and younger post-peat areas, (3) to explain current changes in peat bogs morphology, (4) to explain changes in water retention in peat deposit, (5) to separate phases in peat bogs relief changes. With that in mind, the direction and rate of change of landforms typical of younger post-peat areas, such as peat extraction scarps, post-extraction hollows, drainage systems including ditches and regulated stream channels, were analyzed. A special emphasis was placed on the period of time when the restoration of such areas has taken place. The paper is based on an analysis of maps produced over the last 230 years as well as on aerial photographs taken since 1965 and on LiDAR data. Fieldwork included the geomorphological and hydrographic mapping of specified landforms within peat bogs using GPS methods. In period prior to human activity peat domes were larger than today and were surrounded by lagg fens and were

  18. Palaeoclimatic records from peat bogs.

    PubMed

    Blackford

    2000-05-01

    The palaeoclimatic record for the past 6000 years, implemented from peat-bog stratigraphy, has been limited by imprecision in dating and climatic interpretation. Recently, dating problems have been addressed by 'wiggle-matched' radiocarbon dates and by volcanic ash layers, promising much tighter correlation between records from different regions. Recent research shows key dates of significant climatic change and tentative evidence for periodicity. Application of time-series analysis, generalized linear modelling and transfer function models to the proxy climate data show how improved climatic reconstructions can be obtained. Peat-derived palaeoclimatic data might explain, as well as describe, climatic changes over timescales of 102-103 years.

  19. Exploring climatic controls on blanket bog litter decomposition across an altitudinal gradient

    NASA Astrophysics Data System (ADS)

    Bell, Michael; Ritson, Jonathan P.; Clark, Joanna M.; Verhoef, Anne; Brazier, Richard E.

    2016-04-01

    The hydrological and ecological functioning of blanket bogs is strongly coupled, involving multiple ecohydrological feedbacks which can affect carbon cycling. Cool and wet conditions inhibit decomposition, and favour the growth of Sphagnum mosses which produce highly recalcitrant litter. A small but persistent imbalance between production and decomposition has led to blanket bogs in the UK accumulating large amounts of carbon. Additionally, healthy bogs provide a suite of other ecosystems services including water regulation and drinking water provision. However, there is concern that climate change could increase rates of litter decomposition and disrupt this carbon sink. Furthermore, it has been argued that the response of these ecosystems in the warmer south west and west of the UK may provide an early analogue for later changes in the more extensive northern peatlands. In order to investigate the effects of climate change on blanket bog litter decomposition, we set-up a litter bag experiment across an altitudinal gradient spanning 200 m of elevation (including a transition from moorland to healthy blanket bog) on Dartmoor, an area of hitherto unstudied, climatically marginal blanket bog in the south west of the UK. At seven sites, water table depth and soil and surface temperature were recorded continuously. Litter bags filled with the litter of three vegetation species dominant on Dartmoor were incubated just below the bog surface and retrieved over a period of 12 months. We found significant differences in the rate of decomposition between species. At all sites, decomposition progressed in the order Calluna vulgaris (dwarf shrub) > Molinia caerulea (graminoid) > Sphagnum (bryophyte). However, while soil temperature did decrease along the altitudinal gradient, being warmer in the lower altitudes, a hypothesised accompanying decrease in decomposition rates did not occur. This could be explained by greater N deposition at the higher elevation sites (estimated

  20. Paired charcoal and tree-ring records of high-frequency Holocene fire from two New Mexico bog sites

    USGS Publications Warehouse

    Allen, C.D.; Anderson, R. Scott; Jass, R.B.; Toney, J.L.; Baisan, C.H.

    2008-01-01

    Two primary methods for reconstructing paleofire occurrence include dendrochronological dating of fire scars and stand ages from live or dead trees (extending back centuries into the past) and sedimentary records of charcoal particles from lakes and bogs, providing perspectives on fire history that can extend back for many thousands of years. Studies using both proxies have become more common in regions where lakes are present and fire frequencies are low, but are rare where high-frequency surface fires dominate and sedimentary deposits are primarily bogs and wetlands. Here we investigate sedimentary and fire-scar records of fire in two small watersheds in northern New Mexico, in settings recently characterised by relatively high-frequency fire where bogs and wetlands (Chihuahuen??os Bog and Alamo Bog) are more common than lakes. Our research demonstrates that: (1) essential features of the sedimentary charcoal record can be reproduced between multiple cores within a bog deposit; (2) evidence from both fire-scarred trees and charcoal deposits documents an anomalous lack of fire since ???1900, compared with the remainder of the Holocene; (3) sedimentary charcoal records probably underestimate the recurrence of fire events at these high-frequency fire sites; and (4) the sedimentary records from these bogs are complicated by factors such as burning and oxidation of these organic deposits, diversity of vegetation patterns within watersheds, and potential bioturbation by ungulates. We consider a suite of particular challenges in developing and interpreting fire histories from bog and wetland settings in the Southwest. The identification of these issues and constraints with interpretation of sedimentary charcoal fire records does not diminish their essential utility in assessing millennial-scale patterns of fire activity in this dry part of North America. ?? IAWF 2008.

  1. Impact of raized bogs on export of carbon and river water chemical composition in Western Siberia

    NASA Astrophysics Data System (ADS)

    Voistinova, Elena

    2010-05-01

    Bogs play an important role in functioning of the biosphere. Specific geochemical environment of the bogs results in formation of the special biogeochemical cycle of the elements. Processes of decay and transformation of organic material define the reductive conditions of bog water, form and migratory mobility of the chemical elements. Particular interest in recent years is aroused by the question of content and dynamics of the carbon in bog and river water according to indicated natural and climatic changes on the territory. The most important parts of the carbon balance in bog ecosystems together with processes of exhalation from deposit surface in the form of CO2 is its export with river water. The results of research carried out in scientific station "Vasyugansky" in south taiga subzone of Western Siberia showed that chemical composition of raised bog water includes high amounts of total iron (2,13 mg/l), ammonium ions (5,33 mg/l), humic and fulvic acids (5,21 mg/l and 45,8 mg/l), dissolved organic carbon (69,1 mg/l), COD (236,93 mgO/l), there are low mineralization and indicators of pH. Carbon comes in bog water in organic compounds: carboxylic acids, phenols, aromatic and paraffin hydrocarbons, organic phosphates, phthalates and other compounds. Formation of river waters composition in the Western Siberia takes place in the following context: high level of bogged river catchments (sometimes up to 70%), excess humidification and low heat provision. Basing on the results of study of hydrochemical runoff in small and medium rivers with different levels of bogged in river catchments (Chaya, Bakchar, Klyuch, Gavrilovka) it was noted that raised bog influence on river waters chemical composition shows in ion runoff decrease, organic substances runoff increase, increase of amounts of total iron, ammonium irons and water pH indicators decrease. Study of humic matters migration is very important in the context of formation of flexible complexes of humic and fulvic

  2. Estimating methane production rates in bogs and landfills by deuterium enrichment of pore water

    USGS Publications Warehouse

    Siegel, D.I.; Chanton, J.P.; Glaser, P.H.; Chasar, L.S.; Rosenberry, D.O.

    2001-01-01

    Raised bogs and municipal waste landfills harbor large populations of methanogens within their domed deposits of anoxic organic matter. Although the methane emissions from these sites have been estimated by various methods, limited data exist on the activity of the methanogens at depth. We therefore analyzed the stable isotopic signature of the pore waters in two raised bogs from northern Minnesota to identify depth intervals in the peat profile where methanogenic metabolism occurs. Methanogenesis enriched the deuterium (2H) content of the deep peat pore waters by as much as +11% (Vienna Standard Mean Sea Water), which compares to a much greater enrichment factor of +70% in leachate from New York City's Fresh Kills landfill. The bog pore waters were isotopically dated by tritium (3H) to be about 35 years old at 1.5 m depth, whereas the landfill leachate was estimated as ~ 17 years old from Darcy flow calculations. According to an isotopic mass balance the observed deuterium enrichment indicates that about 1.2 g of CH4m-3 d-1 were produced within the deeper peat, compared to about 2.8 g CH4 m-3 d-1 in the landfill. The values for methane production in the bog peat are substantially higher than the flux rates measured at the surface of the bogs or at the landfill, indicating that deeper methane production may be much higher than was previously assumed.

  3. Estimating methane production rates in bogs and landfills by deuterium enrichment of pore water

    NASA Astrophysics Data System (ADS)

    Siegel, D. I.; Chanton, J. R.; Glaser, P. H.; Chasar, L. S.; Rosenberry, D. O.

    2001-12-01

    Raised bogs and municipal waste landfills harbor large populations of methanogens within their domed deposits of anoxic organic matter. Although the methane emissions from these sites have been estimated by various methods, limited data exist on the activity of the methanogens at depth. We therefore analyzed the stable isotopic signature of the pore waters in two raised bogs from northern Minnesota to identify depth intervals in the peat profile where methanogenic metabolism occurs. Methanogenesis enriched the deuterium (2H) content of the deep peat pore waters by as much as +11‰ (Vienna Standard Mean Sea Water), which compares to a much greater enrichment factor of +70‰ in leachate from New York City's Fresh Kills landfill. The bog pore waters were isotopically dated by tritium (3H) to be about 35 years old at 1.5 m depth, whereas the landfill leachate was estimated as ˜17 years old from Darcy flow calculations. According to an isotopic mass balance the observed deuterium enrichment indicates that about 1.2 g of CH4 m-3 d-1 were produced within the deeper peat, compared to about 2.8 g CH4 m-3 d-1 in the landfill. The values for methane production in the bog peat are substantially higher than the flux rates measured at the surface of the bogs or at the landfill, indicating that deeper methane production may be much higher than was previously assumed.

  4. Pre- and syn-ore zonation in Precambrian uraniferous sodic metasomatities

    SciTech Connect

    Omel'yanenko, B.I.; Mineyeva, I.G.

    1982-04-01

    Uraniferous-sodic metasomatites in Precambrian basement faults, in which a regular change in the mineral composition in vertical section has been established are described. The authors attempt to show that this pattern is controlled by the evolution of the solutions in time and space, and that it is an expression of a verticle metasomatic zonation. (JMT)

  5. Atmospheric carbonyl sulfide exchange in bog microcosms

    SciTech Connect

    Fried, A.; Klinger, L.F.; Erickson, D.J. III )

    1993-01-22

    Measurements of Carbonyl sulfide (OCS) fluxes were carried out on bog microcosms using chamber sampling and tunable diode laser analysis. Intact bog microcosms (vascular plants, mosses, and peat) removed ambient levels of OCS in the light and dark with rates from [minus]2.4 to [minus]8.1 ng S min[sup [minus]1] m[sup [minus]2]. Peat and peat plus mosses emitted OCS in the light with rates of 17.4 and 10.9 ng S min[sup [minus]1] m[sup [minus]2], respectively. In the dark, the mosses apparently removed OCS at a rate equivalent to the peat emissions. A 3-D numerical tracer model using this data indicated that boreal bog ecosystems remove at most 1% of ambient OCS, not sufficient to account for an observed OCS depletion in boreal air masses. 13 refs., 1 fig., 1 tab.

  6. Ferricrete, manganocrete, and bog iron occurrences with selected sedge bogs and active iron bogs and springs in the upper Animas River watershed, San Juan County, Colorado

    USGS Publications Warehouse

    Yager, Douglas B.; Church, Stanley E.; Verplanck, Philip L.; Wirt, Laurie

    2003-01-01

    During 1996 to 2000, the Bureau of Land Management, National Park Service, Environmental Protection Agency, United States Department of Agriculture (USDA) Forest Service, and the U.S. Geological Survey (USGS) developed a coordinated strategy to (1) study the environmental effects of historical mining on Federal lands, and (2) remediate contaminated sites that have the greatest impact on water quality and ecosystem health. This dataset provides information that contributes to these overall objectives and is part of the USGS Abandoned Mine Lands Initiative. Data presented here represent ferricrete occurrences and selected iron bogs and springs in the upper Animas River watershed in San Juan County near Silverton, Colorado. Ferricretes (stratified iron and manganese oxyhydroxide-cemented sedimentary deposits) are one indicator of the geochemical baseline conditions as well as the effect that weathering of mineralized rocks had on water quality in the Animas River watershed prior to mining. Logs and wood fragments preserved in several ferricretes in the upper Animas River watershed, collected primarily along streams, yield radiocarbon ages of modern to 9,580 years B.P. (P.L. Verplanck, D.B. Yager, and S.E. Church, work in progress). The presence of ferricrete deposits along the current stream courses indicates that climate and physiography of the Animas River watershed have been relatively constant throughout the Holocene and that weathering processes have been ongoing for thousands of years prior to historical mining activities. Thus, by knowing where ferricrete is preserved in the watershed today, land-management agencies have an indication of (1) where metal precipitation from weathering of altered rocks has occurred in the past, and (2) where this process is ongoing and may confound remediation efforts. These data are included as two coverages-a ferricrete coverage and a bogs and springs coverage. The coverages are included in ArcInfo shapefile and Arc

  7. Environmental controls of greenhouse gas release in a restoring peat bog in NW Germany

    NASA Astrophysics Data System (ADS)

    Glatzel, S.; Forbrich, I.; Krüger, C.; Lemke, S.; Gerold, G.

    2008-01-01

    In Central Europe, most bogs have a history of drainage and many of them are currently being restored. Success of restoration as well as greenhouse gas exchange of these bogs is influenced by environmental stress factors as drought and atmospheric nitrogen deposition. We determined the methane and nitrous oxide exchange of sites in the strongly decomposed center and less decomposed edge of the Pietzmoor bog in NW Germany in 2004. Also, we examined the methane and nitrous oxide exchange of mesocosms from the center and edge before, during, and following a drainage experiment as well as carbon dioxide release from disturbed unfertilized and nitrogen fertilized surface peat. In the field, methane fluxes ranged from 0 to 3.8 mg m-2 h-1 and were highest from hollows. Field nitrous oxide fluxes ranged from 0 to 574 μg m-2 h-1 and were elevated at the edge. A large Eriophorum vaginatum tussock showed decreasing nitrous oxide release as the season progressed. Drainage of mesocosms decreased methane release to 0, even during rewetting. There was a tendency for a decrease of nitrous oxide release during drainage and for an increase in nitrous oxide release during rewetting. Nitrogen fertilization did not increase decomposition of surface peat. Our examinations suggest a competition between vascular vegetation and denitrifiers for excess nitrogen. We also provide evidence that the von Post humification index can be used to explain greenhouse gas release from bogs, if the role of vascular vegetation is also considered. An assessment of the greenhouse gas release from nitrogen saturated restoring bogs needs to take into account elevated release from fresh Sphagnum peat as well as from sedges growing on decomposed peat. Given the high atmospheric nitrogen deposition, restoration will not be able to achieve an oligotrophic ecosystem in the short term.

  8. [Methanotrophic bacteria of acid sphagnum bogs].

    PubMed

    Dedysh, S N

    2002-01-01

    Acid sphagnum bogs cover a considerable part of the territory of Russia and are an important natural source of biogenic methane, which is formed in their anaerobic layers. A considerable portion of this methane is consumed in the aerobic part of the bog profile by acidophilic methanotrophic bacteria, which comprise the methane filter of sphagnum bogs and decrease CH4 emission to the atmosphere. For a long time, these bacteria escaped isolation, which became possible only after the elucidation of the optimal conditions of their functioning in situ: pH 4.5 to 5.5; temperature, from 15 to 20 degrees C; and low salt concentration in the solution. Reproduction of these conditions and rejection of earlier used media with a high content of biogenic elements allowed methanotrophic bacteria of two new genera and species--Methylocella palustris and Methylocapsa acidophila--to be isolated from the peat of sphagnum bogs of the northern part of European Russia and West Siberia. These bacteria are well adapted to the conditions in cold, acid, oligotrophic sphagnum bogs. They grow in a pH range of 4.2-7.5 with an optimum at 5.0-5.5, prefer moderate temperatures (15-25 degrees C) and media with a low content of mineral salts (200-500 mg/l), and are capable of active nitrogen fixation. Design of fluorescently labeled 16S rRNA-targeted oligonucleotide probes for the detection of Methylocella palustris and Methylocapsa acidophila and their application to the analysis of sphagnum peat samples showed that these bacteria represent dominant populations of methanotrophs with a density of 10(5)-10(6) cells/g peat. In addition to Methylocella and Methylocapsa populations, one more abundant population of methanotrophs was revealed (10(6) cells/g peat), which were phylogenetically close to the genus Methylocystis. PMID:12526194

  9. U-Pb ages of uraniferous opals and implications for the history of beryllium, fluorine, and uranium mineralization at Spor Mountain, Utah

    USGS Publications Warehouse

    Ludwig, K. R.; Lindsey, D.A.; Zielinski, R.A.; Simmons, K.R.

    1980-01-01

    The U-Pb isotope systematics of uraniferous opals from Spor Mountain, Utah, were investigated to determine the suitability of such material for geochronologic purposes, and to estimate the timing of uranium and associated beryllium and fluorine mineralization. The results indicate that uraniferous opals can approximate a closed system for uranium and uranium daughters, so that dating samples as young as ???1 m.y. should be possible. In addition, the expected lack of initial 230Th and 231Pa in opals permits valuable information on the initial 234U/238U to be obtained on suitable samples of ???10 m.y. age. The oldest 207Pb/235U apparent age observed, 20.8 ?? 1 m.y., was that of the opal-fluorite core of a nodule from a beryllium deposit in the Spor Mountain Formation. This age is indistinguishable from that of fission-track and K-Ar ages from the host rhyolite, and links the mineralization to the first episode of alkali rhyolite magmatism and related hydrothermal activity at Spor Mountain. Successively younger ages of 13 m.y. and 8-9 m.y. on concentric outer zones of the same nodule indicate that opal formed either episodically or continuously for over 10 m.y. Several samples of both fracture-filling and massive-nodule opal associated with beryllium deposits gave 207Pb/235U apparent ages of 13-16 m.y., which may reflect a restricted period of mineralization or perhaps an averaging of 21- and <13-m.y. periods of opal growth. Several samples of fracture-filling opal in volcanic rocks as young as 6 m.y. gave 207Pb/235U ages of 3.4-4.8 m.y. These ages may reflect hot-spring activity after the last major eruption of alkali rhyolite. ?? 1980.

  10. Late Holocene palaeoclimate variability: The significance of bog pine dendrochronology related to peat stratigraphy. The Puścizna Wielka raised bog case study (Orawa - Nowy Targ Basin, Polish Inner Carpathians)

    NASA Astrophysics Data System (ADS)

    Krąpiec, Marek; Margielewski, Włodzimierz; Korzeń, Katarzyna; Szychowska-Krąpiec, Elżbieta; Nalepka, Dorota; Łajczak, Adam

    2016-09-01

    The results of dendrochronological and palynological analyses of subfossil pine trees occurring in the peat deposits of the Puścizna Wielka raised bog (Polish Carpathians, Southern Poland) - the only site with numerous subfossil pine trees in the mountainous regions of Central Europe presently known - indicate that the majority of the tree populations grew in the peat bog during the periods ca 5415-3940 cal BP and 3050-2560 cal BP. Several forestless episodes, dated to 5245-5155 cal BP, 4525-4395 cal BP and 3940-3050 cal BP, were preceded by tree dying-off phases caused by an extreme periodical increase in humidity and general climate cooling trends. These events are documented based on analyses of pollen and non-pollen palynomorph assemblages, dendrochronological analyses of the trees, as well as numerous radiocarbon datings of the sediment horizons occurring within the peat bog profile. The phases of germinations, and, in turn, of tree and shrub invasions of the peat bog areas have been closely connected to drying and occasional warming of the regional climate. The last of the forestless periods began about 2600 years ago and continued up to the very recent times. Currently, as a result of desiccation of the peat bog and the lowering of the groundwater level (due to improved water drainage system), pine trees have returned the peat bog again. These results demonstrate that studies of subfossil bog-pine trees are quite effective in documenting and reconstructing periods of humidity fluctuation that occurred within the Carpathian region over the last several millennia.

  11. Uranium deposits at Shinarump Mesa and some adjacent areas in the Temple Mountain district, Emery County, Utah

    USGS Publications Warehouse

    Wyant, Donald G.

    1953-01-01

    Deposits of uraniferous hydrocarbons are associated with carnotite in the Shinarump conglomerate of Triassic age at Shinarump Mesa and adjacent areas of the Temple Mountain district in the San Rafael Swell of Emery County, Utah. The irregular ore bodies of carnotite-bearing sandstone are genetically related to lenticular uraniferous ore bodies containing disseminated asphaltitic and humic hydrocarbon in permeable sandstones and were localized indirectly by sedimentary controls. Nearly non-uraniferous bitumen commonly permeates the sandstones in the Shinarump conglomerate and the underlying Moekopi formation in the area. The ore deposits at Temple Mountain have been altered locally by hydrothermal solutions, and in other deposits throughout the area carnotite has been transported by ground and surface water. Uraniferous asphaltite is thought to be the non-volatile residue of an original weakly uraniferous crude oil that migrated into the San Rafael anticline; the ore metals concentrated in the asphaltite as the oil was devolatilized and polymerized. Carnotite is thought to have formed from the asphaltite by ground water leaching. It is concluded that additional study of the genesis of the asphaltitic uranium ores in the San Rafael Swell, of the processes by which the hydrocarbons interact and are modified (such as heat, polymerization, and hydrogenation under the influence of alpha-ray bombardment), of petroleum source beds, and of volcanic intrusive rocks of Tertiary age are of fundamental importance in the continuing study of the uranium deposits on the Colorado Plateau.

  12. Peat decomposition records in three pristine ombrotrophic bogs in southern Patagonia

    NASA Astrophysics Data System (ADS)

    Broder, T.; Blodau, C.; Biester, H.; Knorr, K. H.

    2012-04-01

    Ombrotrophic bogs in southern Patagonia have been examined with regard to paleoclimatic and geochemical research questions but knowledge about organic matter decomposition in these bogs is limited. Therefore, we examined peat humification with depth by Fourier Transformed Infrared (FTIR) measurements of solid peat, C/N ratio, and δ13C and δ15N isotope measurements in three bog sites. Peat decomposition generally increased with depth but distinct small scale variation occurred, reflecting fluctuations in factors controlling decomposition. C/N ratios varied mostly between 40 and 120 and were significantly correlated (R2 > 0.55, p < 0.01) with FTIR-derived humification indices. The degree of decomposition was lowest at a site presently dominated by Sphagnum mosses. The peat was most strongly decomposed at the driest site, where currently peat-forming vegetation produced less refractory organic material, possibly due to fertilizing effects of high sea spray deposition. Decomposition of peat was also advanced near ash layers, suggesting a stimulation of decomposition by ash deposition. Values of δ13C were 26.5 ± 2‰ in the peat and partly related to decomposition indices, while δ15N in the peat varied around zero and did not consistently relate to any decomposition index. Concentrations of DOM partly related to C/N ratios, partly to FTIR derived indices. They were not conclusively linked to the decomposition degree of the peat. DOM was enriched in 13C and in 15N relative to the solid phase probably due to multiple microbial modifications and recycling of N in these N-poor environments. In summary, the depth profiles of C/N ratios, δ13C values, and FTIR spectra seemed to reflect changes in environmental conditions affecting decomposition, such as bog wetness, but were dominated by site specific factors, and are further influenced by ash deposition and possibly by sea spray input.

  13. Peat bogs and their organic soils: Archives of atmospheric change and global environmentalsignificance (Philippe Duchaufour Medal Lecture)

    NASA Astrophysics Data System (ADS)

    Shotyk, William

    2013-04-01

    A bog is much more than a waterlogged ecosystem where organic matter accumulates as peat. Peatlands such as bogs represent a critical link between the atmosphere, hydrosphere, and biosphere. Plants growing at the surface of ombrotrophic bogs receive nutrients exclusively from the atmosphere. Despite the variations in redox status caused by seasonal fluctuations in depth to water table, the low pHof the waters, and abundance of dissolved organic matter, bogs preserve a remarkably reproducible history of atmospheric pollution, climate change, landscape evolution and human history. For example, peat cores from bogs in Europe and North America have provided detailed reconstructions of the changing rates and sources of Ag, Cd, Hg, Pb, Sb, and Tl, providing new insights into the geochemical cycles of these elements, including the massive perturbations induced by human activities beginning many thousands of years ago. Despite the low pH, and perhaps because of the abundance of dissolved organic matter, bogs preserve many silicate and aluminosilicate minerals which renders them valuable archives of atmospheric dust deposition and the climate changes which drive them. In the deeper, basal peat layers of the bog, in the minerotrophic zone where pore waters are affected bymineral-water interactions in the underlying and surrounding soils and sediments, peat serves as animportant link to the hydrosphere, efficiently removing from the imbibed groundwaters such trace elements as As, Cu, Mo, Ni, Se, V, and U. These removal processes, while incompletely understood, are so effective that measuring the dissolved fraction of trace elements in the pore waters becomes a considerable challenge even for the most sophisticated analytical laboratories. While the trace elements listed above are removed from groundwaters (along with P and S), elements such as Fe and Mn are added to the waters because of reductive dissolution, an important first step in the formation of lacustrine Fe and Mn

  14. Bog discharge from different viewpoints: comparison of Ingram's theory with observations from an Estonian raised bog

    NASA Astrophysics Data System (ADS)

    Oosterwoud, Marieke; van der Ploeg, Martine; van der Zee, Sjoerd

    2013-04-01

    Raised bogs are typically dome shaped and have a groundwater level located close to the soil surface. Besides their typical dome shape, these peatlands are often characterized by a pronounced surface topography consisting of pools, wet depressions (hollows), stretches of Sphagnum species (lawns), drier mounds (hummocks) and higher drier areas with terrestrial vegetation (ridges). These peat bodies drain laterally by gravity to adjacent areas with lower groundwater levels. The integrity of these bogs is only ascertained when water is stored in the peat body in periods of precipitation deficit and efficiently removed in wet periods. This is realized by the fact that the bog's top layer, often called acrotelm, has a variable hydraulic conductivity. In response to precipitation its hydraulic conductivity increases, whereas, under evaporative demand the water table lowers and therefore also the hydraulic conductivity decreases. Ingram proposed a model based on the Dupuit-Forchheimer approximation for Darcy's law that assumes vertical flow is negligible, and the slope of the water table is equal to the hydraulic gradient. U- Hm2- K = L2 (1) where U is net recharge (P-ET), K is horizontal hydraulic conductivity, Hm is hydraulic head above a flat bottom at the centre of the bog, L is half the width of the bog along the cross section. This model incorporates the assumption that all net rainfall reaching the water table will be discharged to the stream. Ingram's model does not consider local heterogeneities in surface topography, like pool-ridge patterns. We hypothesize that under drier conditions it is likely that pool-ridge patterning will inhibit water from flowing along the surface gradient. Under wet conditions, however, pools can become connected and water can move through the upper highly permeable layer of ridges. In this study, we investigated the influence of ridge-pool patterning on the horizontal water flow through a raised bog and compared it with Ingram

  15. Deposited atmospheric chemicals

    SciTech Connect

    Schell, W.R.

    1986-09-01

    A mountaintop bog in western Pennsylvania serves as a reservoir for materials deposited from the atmosphere. Biological activity in the bog decomposes plant matter, which becomes humified and mineralized at increasing depths. Little or no mixing of elements occurs below the active root zone. Radionuclides produced by natural means and by nuclear weapons have been used to measure the ages of the layers deposited during the growing season of each year. The upper layers of the bog indicate that the deposition of total sulfur is at least 20 times and that of nitrogen is 45 times the value estimated prior to cutting the forest, with a doubling time for each of 25-35 yr. Bromine deposition also doubles every 35 yr. The pattern of mass and element deposition illustrates the changes in land use and industrial effluents that were sources for the material deposited on the bog. The decrease in atmospheric particle removal shows up in the 1960 and later layers. Compared with terrestrial abundances, the relative enrichments over time for chlorine, nitrogen, sulfur, and bromine are more than 100 times those calculated for 1817; lead, calcium, and antimony are 10 to 40 times greater.

  16. Isotopic evidence for nitrogen mobility in peat bogs

    NASA Astrophysics Data System (ADS)

    Novak, Martin; Stepanova, Marketa; Jackova, Ivana; Vile, Melanie A.; Wieder, R. Kelman; Buzek, Frantisek; Adamova, Marie; Erbanova, Lucie; Fottova, Daniela; Komarek, Arnost

    2014-05-01

    Elevated nitrogen (N) input may reduce carbon (C) storage in peat. Under low atmospheric deposition, most N is bound in the moss layer. Under high N inputs, Sphagnum is not able to prevent penetration of dissolved N to deeper peat. Nitrogen may become available to the roots of invading vascular plants. The concurrent oxygenation of deeper peat layers, along with higher supply of labile organic C, may enhance microbial decomposition and lead to peat thinning. The resulting higher emissions of greenhouse gases may accelerate global warming. Seepage of N to deeper peat has never been quantified. Here we present evidence for post-depositional mobility of atmogenic N in peat, based on natural-abundance N isotope ratios. We conducted a reciprocal peat transplant experiment between two Sphagnum-dominated peat bogs in the Czech Republic (Central Europe), differing in anthropogenic N inputs. The northern site VJ received as much as 33 kg N ha-1 yr-1 via spruce canopy throughfall. The southern site was less polluted (17.6 kg N ha-1 yr-1). Isotope signatures of living moss differed between the two sites (δ15N of -3‰ and -7‰ at VJ and CB, respectively). After 18 months, an isotope mass balance was constructed. In the CB-to-VJ transplant, a significant portion of original CB nitrogen (98-31%) was removed and replaced by nitrogen of the host site throughout the top 10 cm of the profile. Nitrogen, deposited at VJ, was immobilized in imported CB peat that was up to 20 years old. Additionally, we compared N concentration and N accumulation rates in 210Pb-dated peat profiles with well-constrained data on historical atmospheric N pollution. Nationwide N emissions peaked in 1990, while VJ exhibited the highest N content in peat that formed in 1930. This de-coupling of N inputs and N retention in peat might be interpreted as a result of translocation of dissolved pollutant N downcore, corroborating our δ15N results at VJ and CB. Data from a variety of peat bogs along pollution

  17. Bog breath: Sleeper factor in global warming?

    SciTech Connect

    Benyus, J.M.

    1995-04-01

    This artical examines the emission of gases from northern peatlands as plants grow and decay and its implication in the global increase in greenhouse gases, particularly carbon dioxide and methane. Bogs do extract carbon dioxide from the air, incorporating it into green plants which become buried for a long time. However, the cold, wet conditions are ideal for microbes which emit methane. Global climate change models indicate that Minnesota, for example will be 5 degrees warmer and somewhat wetter in future years. As a result bacterial metabolism and methane generation may increase considerably. This paper discusses current research and speculation and looks at possible solutions, both man-created and natural.

  18. Comparisons of soil nitrogen mass balances for an ombrotrophic bog and a minerotrophic fen in northern Minnesota.

    PubMed

    Hill, Brian H; Jicha, Terri M; Lehto, LaRae L P; Elonen, Colleen M; Sebestyen, Stephen D; Kolka, Randall K

    2016-04-15

    We compared nitrogen (N) storage and flux in soils from an ombrotrophic bog with that of a minerotrophic fen to quantify the differences in N cycling between these two peatlands types in northern Minnesota (USA). Precipitation, atmospheric deposition, and bog and fen outflows were analyzed for nitrogen species. Upland and peatland soil samples were analyzed for N content, and for ambient (DN) and potential (DEA) denitrification rates. Annual atmospheric deposition was: 0.88-3.07kg NH4(+)ha(-1)y(-1); 1.37-1.42kg NO3(-)ha(-1)y(-1); 2.79-4.69kg TNha(-1)y(-1). Annual N outflows were: bog-0.01-0.04kg NH4(+)ha(-1)y(-1), NO3(-) 0.01-0.06kgha(-1)y(-1), and TN 0.11-0.69kgha(-1)y(-1); fen-NH4(+) 0.01-0.16kgha(-1)y(-1), NO3(-) 0.29-0.48kgha(-1)y(-1), and TN 1.14-1.61kgha(-1)y(-1). Soil N content depended on location within the bog or fen, and on soil depth. DN and DEA rates were low throughout the uplands and peatlands, and were correlated with atmospheric N deposition, soil N storage, and N outflow. DEA was significantly greater than DN indicating C or N limitation of the denitrification process. We highlight differences between the bog and fen, between the upland mineral soils and peat, and the importance of biogeochemical hotspots within the peatlands. We point out the importance of organic N storage, as a source of N for denitrification, and propose a plausible link between organic N storage, denitrification and N export from peatlands. Finally, we considered the interactions of microbial metabolism with nutrient availability and stoichiometry, and how N dynamics might be affected by climate change in peatland ecosystems. PMID:26851760

  19. Comparisons of soil nitrogen mass balances for an ombrotrophic bog and a minerotrophic fen in northern Minnesota.

    PubMed

    Hill, Brian H; Jicha, Terri M; Lehto, LaRae L P; Elonen, Colleen M; Sebestyen, Stephen D; Kolka, Randall K

    2016-04-15

    We compared nitrogen (N) storage and flux in soils from an ombrotrophic bog with that of a minerotrophic fen to quantify the differences in N cycling between these two peatlands types in northern Minnesota (USA). Precipitation, atmospheric deposition, and bog and fen outflows were analyzed for nitrogen species. Upland and peatland soil samples were analyzed for N content, and for ambient (DN) and potential (DEA) denitrification rates. Annual atmospheric deposition was: 0.88-3.07kg NH4(+)ha(-1)y(-1); 1.37-1.42kg NO3(-)ha(-1)y(-1); 2.79-4.69kg TNha(-1)y(-1). Annual N outflows were: bog-0.01-0.04kg NH4(+)ha(-1)y(-1), NO3(-) 0.01-0.06kgha(-1)y(-1), and TN 0.11-0.69kgha(-1)y(-1); fen-NH4(+) 0.01-0.16kgha(-1)y(-1), NO3(-) 0.29-0.48kgha(-1)y(-1), and TN 1.14-1.61kgha(-1)y(-1). Soil N content depended on location within the bog or fen, and on soil depth. DN and DEA rates were low throughout the uplands and peatlands, and were correlated with atmospheric N deposition, soil N storage, and N outflow. DEA was significantly greater than DN indicating C or N limitation of the denitrification process. We highlight differences between the bog and fen, between the upland mineral soils and peat, and the importance of biogeochemical hotspots within the peatlands. We point out the importance of organic N storage, as a source of N for denitrification, and propose a plausible link between organic N storage, denitrification and N export from peatlands. Finally, we considered the interactions of microbial metabolism with nutrient availability and stoichiometry, and how N dynamics might be affected by climate change in peatland ecosystems.

  20. Geoinformatics meets education for a peat bog information system

    NASA Astrophysics Data System (ADS)

    Michel, Ulrich; Fiene, Christina; Plass, Christian

    2010-10-01

    Within the project "Expedition Bog: Young researchers are experimenting, exploring and discovering" a bog-information- system is developed by the Department of Geography (University of Education Heidelberg, Germany), the Institute for Geoinformatics and Remote Sensing (University of Osnabrueck, Germany; the NABU Umweltpyramide gGmbH. This information system will be available for schools and to the public. It is supplemented by teaching units on various topics around the bog via an online platform. The focus of the project, however, is the original encounter with the bog habitat. This is realized by a GPS scavenger hunt with small research tasks and observations, mapping and experiments. The project areas are the Huvenhoops bog and the Lauenbruecker bog in Rotenburg in Lower Saxony, Germany. Equipped with a researcher backpack, GPS device and a mobile bog book by means of a pocket PC, students can discover different learning stations in the project bogs. In our areas the students can learn more about different topics such as "the historical memory of the bog", "water", "peat moss and other plants" and "animals of the bog". Moreover small inquiry research projects can be executed. Experimenting on site helps students to develop important scientific findings and increases their curiosity and enthusiasm for nature. It also promotes a number of other basic skills such as literacy, language skills, social skills or fine motor skills. Moreover it also fosters the development of a positive attitude to science in general. The main objective of the project is to promote sustainable environmental education, as well as the development of environmental awareness. This will be accomplished through the imparting of knowledge but also through experiencing nature with all senses in the context of original encounters.

  1. Response of douglas fir (Pseudotsuga menziesii) to uraniferous groundwater in a small glaciated drainage, Northeastern Washington State

    USGS Publications Warehouse

    Zielinski, R.A.; Schumann, R.R.

    1987-01-01

    Douglas fir trees and associated soils were sampled from the slopes of a small (???4 km2) drainage basin in northeastern Washington to investigate the biogeochemical response to locally uraniferous groundwater. Uranium is preferentially incorporated in needles and twigs compared to larger branches or the trunk. The U concentration in needle ash ranges from 0.2 to 5.8??g g-1 (ppm) and shows no correlation with the U concentration in associated soils. Rather, the distribution of anomalously uraniferous douglas fir (> 1.0??g g-1 U in needle ash) appears to be controlled by observed or readily inferred pathways of near-surface groundwater movement in the drainage. These pathways include: (1) general downslope movement of subsurface runoff; (2) increased flux of near-surface groundwater near the toe of an alluvial fan; and (3) emergence of uraniferous (100-150 ng ml-1 [ppb] groundwater in the vicinity of a slope spring. The data also indicate the presence of near-surface uraniferous groundwater along a structurally controlled zone that parallels the north-south strike of the valley, and that includes the slope spring. The results suggest that biogeochemical sampling may be used to supplement more direct, but more limited, measurements of groundwater quality and flow regime in areas of near-surface contaminated groundwater. ?? 1987.

  2. Response of douglas fir (Pseudotsuga menziesii) to uraniferous groundwater in a small glaciated drainage, Northeastern Washington State

    USGS Publications Warehouse

    Zielinski, R.A.; Schumann, R.R.

    1987-01-01

    Douglas fir trees and associated soils were sampled from the slopes of a small (??? 4 km2) drainage basin in northeastern Washington to investigate the biogeochemical response to locally uraniferous groundwater. Uranium is preferentially incorporated in needles and twigs compared to larger branches or the trunk. The U concentration in needle ash ranges from 0.2 to 5.8 ??g g-1 (ppm) and shows no correlation with the U concentration in associated soils. Rather, the distribution of anomalously uraniferous douglas fir (>1.0??g g-1 U in needle ash) appears to be controlled by observed or readily inferred pathways of near-surface groundwater movement in the drainage. These pathways include: (1) general downslope movement of subsurface runoff; (2) increased flux of near-surface groundwater near the toe of an alluvial fan; and (3) emergence of uraniferous (100-150 ng ml-1 [ppb] groundwater in the vicinity of a slope spring. The data also indicate the presence of near-surface uraniferous groundwater along a structurally controlled zone that parallels the north-south strike of the valley, and that includes the slope spring. The results suggest that biogeochemical sampling may be used to supplement more direct, but more limited, measurements of groundwater quality and flow regime in areas of near-surface contaminated groundwater. ?? 1987.

  3. Uraniferous asphaltite in Moore and Potter Counties, Texas

    SciTech Connect

    Handford, C.R.; Granata, G.E.

    1980-06-01

    Asphaltite is present in facies of the Red Cave and Panhandle lime Formation. Drill cuttings from 30 Moore County wells and 4 cores distributed across Moore and Potter Counties were examined for asphaltite. Results show that asphaltite is widespread but seems to be most abundant over structural highs, and that there is a facies control of asphaltite occurrences. In drill cuttings sandstones contain most abundant nodules yet the nodules are generally very small. Largest nodules were commonly observed in mudstone core samples. A potential exploration program should take those observations into account. Once exploitable deposits are located and if proper in situ leaching materials were developed for extraction of uranium, only sandstones could be worked. Interchannel mudstones are too impermeable and nonporous. Subsurface mining would be forced to address potential problems derived from high concentrations of hydrocarbons in the target rocks (Red Cave Formation produces oil and gas in Moore County) as well as high levels of radon (averages 100 x 10/sup -12/ curies per liter STP) in gas produced from the Panhandle Field.

  4. Experimental study on performance of BOG compressor

    NASA Astrophysics Data System (ADS)

    Zhao, Bin; Wang, Tao; Peng, Xueyuan; Feng, Jianmei

    2015-08-01

    The boil-off gas (BOG) compressor is widely used for recycling the excessive boil-off gas of liquefied natural gas (LNG), and the extra-low suction temperature brings about great challenges to design of the BOG compressor. In this paper, a test system was built to examine the effects of low suction temperature on the compressor performance, in which the lowest temperature reached -178°C by means of a plate-fin heat exchanger with liquefied nitrogen. The test results showed that, as the suction temperature decreased from 20°C to -150°C, the volumetric efficiency of the compressor dropped by 37.0%, and the power consumption decreased by 10.0%. The preheat of the gas by the pipe through the suction flange to suction valve was larger than 20°C as the suction temperature was -150°C, and this value increased with the decreased suction temperature. The pressure loss through the suction valve at lower suction temperature was larger than that at ambient temperature while the volume flow rate was kept the same.

  5. Nest-site characteristics of Glyptemys muhlenbergii (Bog Turtle) in New Jersey and Pennsylvania

    USGS Publications Warehouse

    Zappalorti, Robert T.; Lovich, Jeffrey E.; Farrell, Ray F.; Torocco, Michael E.

    2015-01-01

    Nest-site selection can affect both the survival and fitness of female turtles and their offspring. In many turtle species, the nest environment determines the thermal regime during incubation, length of incubation period, sex ratio of the hatchlings, and exposure to predators and other forms of mortality for both mothers and their offspring. Between 1974 and 2012, we collected detailed data on habitat variables at 66 Glyptemys muhlenbergii (Bog Turtle) nests in 9 different bogs, fens, and wetland complexes in New Jersey and Pennsylvania. The nests had a mean elevation above the substrate of 8.2 cm, and many were shallow and located in raised tussocks of grass or sedges. Females covered most nests, but we also observed partially or completely uncovered eggs. Some females deposited eggs in communal nests; we found 4 nests with 2 separate clutches, and 2 nests with 3 clutches. Principal component analysis confirmed the importance of cover and vegetation to nest-site selection in this species. Availability of open, shade-free, wet nesting areas is an important habitat requirement for Bog Turtles.

  6. Can a bog drained for forestry be a stronger carbon sink than a natural bog forest?

    NASA Astrophysics Data System (ADS)

    Hommeltenberg, J.; Schmid, H. P.; Drösler, M.; Werle, P.

    2014-07-01

    This study compares the CO2 exchange of a natural bog forest, and of a bog drained for forestry in the pre-Alpine region of southern Germany. The sites are separated by only 10 km, they share the same soil formation history and are exposed to the same climate and weather conditions. In contrast, they differ in land use history: at the Schechenfilz site a natural bog-pine forest (Pinus mugo ssp. rotundata) grows on an undisturbed, about 5 m thick peat layer; at Mooseurach a planted spruce forest (Picea abies) grows on drained and degraded peat (3.4 m). The net ecosystem exchange of CO2 (NEE) at both sites has been investigated for 2 years (July 2010-June 2012), using the eddy covariance technique. Our results indicate that the drained, forested bog at Mooseurach is a much stronger carbon dioxide sink (-130 ± 31 and -300 ± 66 g C m-2 a-1 in the first and second year, respectively) than the natural bog forest at Schechenfilz (-53 ± 28 and -73 ± 38 g C m-2 a-1). The strong net CO2 uptake can be explained by the high gross primary productivity of the 44-year old spruces that over-compensates the two-times stronger ecosystem respiration at the drained site. The larger productivity of the spruces can be clearly attributed to the larger plant area index (PAI) of the spruce site. However, even though current flux measurements indicate strong CO2 uptake of the drained spruce forest, the site is a strong net CO2 source when the whole life-cycle since forest planting is considered. It is important to access this result in terms of the long-term biome balance. To do so, we used historical data to estimate the difference between carbon fixation by the spruces and the carbon loss from the peat due to drainage since forest planting. This rough estimate indicates a strong carbon release of +134 t C ha-1 within the last 44 years. Thus, the spruces would need to grow for another 100 years at about the current rate, to compensate the potential peat loss of the former years. In

  7. Can a bog drained for forestry be a stronger carbon sink than a natural bog forest?

    NASA Astrophysics Data System (ADS)

    Hommeltenberg, J.; Schmid, H. P.; Droesler, M.; Werle, P.

    2014-02-01

    This study compares the CO2 exchange of a natural bog forest, and of a bog drained for forestry in the pre-alpine region of southern Germany. The sites are separated by only ten kilometers, they share the same formation history and are exposed to the same climate and weather conditions. In contrast, they differ in land use history: at the Schechenfilz site a natural bog-pine forest (Pinus mugo rotundata) grows on an undisturbed, about 5 m thick peat layer; at Mooseurach a planted spruce forest (Picea abies) grows on drained and degraded peat (3.4 m). The net ecosystem exchange of CO2 (NEE) at both sites has been investigated for two years (July 2010 to June 2012), using the eddy covariance technique. Our results indicate that the drained, forested bog at Mooseurach is a much stronger carbon dioxide sink (-130 ± 31 and -300 ± 66 g C m-2 a-1 in the first and second year respectively) than the natural bog forest at Schechenfilz (-53 ± 28 and -73±38 g C m-2 a-1). The strong net CO2 uptake can be explained by the high gross primary productivity of the spruces that over-compensates the two times stronger ecosystem respiration at the drained site. The larger productivity of the spruces can be clearly attributed to the larger LAI of the spruce site. However, even though current flux measurements indicate strong CO2 uptake of the drained spruce forest, the site is a strong net CO2 source, if the whole life-cycle, since forest planting is considered. We determined the difference between carbon fixation by the spruces and the carbon loss from the peat due to drainage since forest planting. The estimate resulted in a strong carbon release of +156 t C ha-1 within the last 44 yr, means the spruces would need to grow for another 100 yr, at the current rate, to compensate the peat loss of the former years. In contrast, the natural bog-pine ecosystem has likely been a small but consistent carbon sink for decades, which our results suggest is very robust regarding short

  8. Near-neutral carbon dioxide balance at a seminatural, temperate bog ecosystem

    NASA Astrophysics Data System (ADS)

    Hurkuck, Miriam; Brümmer, Christian; Kutsch, Werner L.

    2016-02-01

    The majority of peatlands in the temperate zone is subjected to drainage and agricultural land use and have been found to be anthropogenic emission hot spots for greenhouse gases. At the same time, many peatlands receive increased atmospheric nitrogen (N) deposition by intensive agricultural practices. Here we provide eddy covariance measurements determining net ecosystem carbon dioxide (CO2) exchange at a protected but moderately drained ombrotrophic bog in Northwestern Germany over three consecutive years. The region is dominated by intensive agricultural land use with total (wet and dry) atmospheric N deposition being about 25 kg N ha-1 yr-1. The investigated peat bog was a small net CO2 sink during all three years ranging from -9 to -73 g C m-2 yr-1. We found temperature- and light-dependent ecosystem respiration (Reco) and gross primary production, respectively, but only weak correlations to water table depths despite large interannual and seasonal variability. Significant short-term effects of atmospheric N deposition on CO2 flux components could not be observed, as the primary controlling factors for N deposition and C sequestration, i.e., fertilization of adjacent fields as well as temperature and light availability, respectively, exceeded potential interactions between the two.

  9. Radioactive waste disposal in simulated peat bog repositories

    SciTech Connect

    Schell, W.R.; Massey, C.D.

    1987-01-01

    The Low Level Radioactive Waste Policy Act of 1980 and the Low Level Radioactive Waste Policy Amendments Act of 1985 have required state governments to be responsible for providing low-level waste (LLW) disposal facilities in their respective areas. Questions are (a) is the technology sufficiently advanced to ensure that radioactive wastes can be stored for 300 to 1000 yr without entering into any uncontrolled area. (b) since actual experience does not exist for nuclear waste disposal over this time period, can the mathematical models developed be tested and verified using unequivocal data. (c) how can the public perception of the problem be addressed and the potential risk assessment of the hazards be communicated. To address the technical problems of nuclear waste disposal in the acid precipitation regions of the Northern Hemisphere, a project was initiated in 1984 to evaluate an alternative method of nuclear waste disposal that may not rely completely on engineered barriers to protect the public. Certain natural biogeochemical systems have been retaining deposited materials since the last Ice Age (12,000 to 15,000 yr). It is the authors belief that the biogeochemical system of wetlands and peat bogs may provide an example of an analogue for a nuclear waste repository system that can be tested and verified over a sufficient time period, at least for the LLW disposal problem.

  10. Peat Bogs as Hotspots for Organoarsenical Formation and Persistence.

    PubMed

    Mikutta, Christian; Rothwell, James J

    2016-04-19

    Peatlands have received significant atmospheric inputs of As and S since the onset of the Industrial Revolution, but the effect of S deposition on the fate of As is largely unknown. It may encompass the formation of As sulfides and organosulfur-bound As, or the indirect stimulation of As biotransformation processes, which are presently not considered as important As immobilization pathways in wetlands. To investigate the immobilization mechanisms of anthropogenically derived As in peatlands subjected to long-term atmospheric pollution, we explored the solid-phase speciation of As, Fe, and S in English peat bogs by X-ray absorption spectroscopy. Additionally, we analyzed the speciation of As in pore- and streamwaters. Linear combination fits of extended X-ray absorption fine structure (EXAFS) data imply that 62-100% (average: 82%) of solid-phase As (Astot: 9-92 mg/kg) was present as organic As(V) and As(III). In agreement with appreciable concentrations of organoarsenicals in surface waters (pH: 4.0-4.4, Eh: 165-190 mV, average Astot: 1.5-129 μg/L), our findings reveal extensive biotransformation of atmospheric As and the enrichment of organoarsenicals in the peat, suggesting that the importance of organometal(loid)s in wetlands subjected to prolonged air pollution is higher than previously assumed.

  11. Peat Bogs as Hotspots for Organoarsenical Formation and Persistence.

    PubMed

    Mikutta, Christian; Rothwell, James J

    2016-04-19

    Peatlands have received significant atmospheric inputs of As and S since the onset of the Industrial Revolution, but the effect of S deposition on the fate of As is largely unknown. It may encompass the formation of As sulfides and organosulfur-bound As, or the indirect stimulation of As biotransformation processes, which are presently not considered as important As immobilization pathways in wetlands. To investigate the immobilization mechanisms of anthropogenically derived As in peatlands subjected to long-term atmospheric pollution, we explored the solid-phase speciation of As, Fe, and S in English peat bogs by X-ray absorption spectroscopy. Additionally, we analyzed the speciation of As in pore- and streamwaters. Linear combination fits of extended X-ray absorption fine structure (EXAFS) data imply that 62-100% (average: 82%) of solid-phase As (Astot: 9-92 mg/kg) was present as organic As(V) and As(III). In agreement with appreciable concentrations of organoarsenicals in surface waters (pH: 4.0-4.4, Eh: 165-190 mV, average Astot: 1.5-129 μg/L), our findings reveal extensive biotransformation of atmospheric As and the enrichment of organoarsenicals in the peat, suggesting that the importance of organometal(loid)s in wetlands subjected to prolonged air pollution is higher than previously assumed. PMID:27034028

  12. Peat Bog Archives: from human history, vegetation change and Holocene climate, to atmospheric dusts and trace elements of natural and anthropogenic origin

    NASA Astrophysics Data System (ADS)

    Shotyk, William

    2010-05-01

    For at least two centuries, peat has been recognized as an excellent archive of environmental change. William Rennie (1807), for example, interpreted stratigraphic changes in Scottish bogs not only in terms of natural changes in paleoclimate, but was also able to identify environmental changes induced by humans, namely deforestation and the hydrological impacts which result from such activities. The use of bogs as archives of climate change in the early 20th century was accelerated by studies of fossil plant remains such as those by Lewis in Scotland, and by systematic investigations of pollen grains pioneered by von Post in Sweden. In Denmark, Glob outlined the remarkably well-preserved remains of bog bodies and associated artefacts (of cloth, wood, ceramic and metal) in Danish bogs. In Britain, Godwin provided an introduction to the use of bogs as archives of human history, vegetation change, and Holocene climate, with a more recent survey provided by Charman. Recent decades have provided many mineralogical studies of peat and there is growing evidence that many silicate minerals, whether derived from the surrounding watershed or the atmosphere (soil-derived dusts and particles emitted from volcanoes), also are well preserved in anoxic peatland waters. Similarly, geochemical studies have shown that a long list of trace metals, of both natural and anthropogenic origin, also are remarkably well preserved in peat bogs. Thus, there is growing evidence that ombrotrophic (ie 'rain-fed') peat bogs are reliable archives of atmospheric deposition of a wide range of trace elements, including conservative, lithogenic metals such as Al, Sc, Ti, Y, Zr, Hf and the REE, but also the potentially toxic Class B, or 'heavy metals' such as Cu, Ag, Hg, Pb, Sb and Tl. When high quality measurements of these elements is combined with accurate radiometric age dating, it becomes possible to create high resolution reconstructions of atmospheric soil dust fluxes, ancient and modern metal

  13. Ecoenzymatic stoichiometry and microbial processing of organic matter in northern bogs and fens reveals a common P limitation among peatland types

    EPA Science Inventory

    We compared C, N, and P concentrations in atmospheric deposition, runoff, and soil standing stocks with microbial respiration (DHA) and ecoenzyme activity (EEA) in an ombrotrophic bog (S2) and a minerotrophic fen (S3) to investigate the environmental drivers of biogeochemical cyc...

  14. Nitrogen dynamics in peat bogs: Comparison of sites with contrasting pollution levels (Central Europe)

    NASA Astrophysics Data System (ADS)

    Novak, Martin; Bohdalkova, Leona; Stepanova, Marketa; Vile, Melanie A.; Wieder, Kelman R.

    2013-04-01

    Nitrogen belongs to chemical elements whose biogeochemical cycles are most heavily disturbed by human activities, and large regions worlwide experience elevated depositions of reactive N (NO3-, NH4+). Peatlands contain as much as 15 % of the world's soil N. It it is unclear whether fertilizing by anthopogenic N will lead to higher storage of C in wetlands. Elevated N input may lead to both higher net primary productivity, but will also augment microbial decomposition. Here we discuss two aspects of N cycling in Sphagnum-dominated bogs in the Czech Republic, an area characterized by a steep north-south pollution gradient and high annual N deposition (60 kg ha-1). These two aspects are N inventory in 210Pb-dated peat cores, and post-depositional mobility of N in peat. We compared the N inventory in two Czech bogs, differing in pollution, with cumulative atmospheric N input. We hypothesized that the total amount of N in the peat cores would be smaller than the cumulative N input (leaching of excess N from the bog, denitrification). The two bogs were VJ (industrial north) and CB (rural south). The investigated period was 1885-2002. The total amount of N was 4020 kg ha-1 at VJ and 1530 kg ha-1 at CB. Peat in the north contained 2.6 times more N than in the south. Historical rates of N deposition in the Czech Republic are well known (numerous papers by Kopacek). To estimate cumulative N inputs into the bogs, we also used the monthly N depositions between 1994 and 2002, measured in two nearby catchments. The estimated cumulative atmospheric N input was 1350 kg ha-1 at VJ, and 530 kg ha-1 at CB. In both cases, the amount of N found in peat was 3 times higher than the estimated atmospheric N input. Such high storage of N in peat is surprising. Post-depositional mobility of N may help to explain the discrepancies between atmospheric N inputs and N storage in peat. We found two-fold evidence for post-depositional mobility of N. Maximum N concentrations at VJ were observed in

  15. Effects of nutrient addition on leaf chemistry, morphology, and photosynthetic capacity of three bog shrubs.

    PubMed

    Bubier, Jill L; Smith, Rose; Juutinen, Sari; Moore, Tim R; Minocha, Rakesh; Long, Stephanie; Minocha, Subhash

    2011-10-01

    Plants in nutrient-poor environments typically have low foliar nitrogen (N) concentrations, long-lived tissues with leaf traits designed to use nutrients efficiently, and low rates of photosynthesis. We postulated that increasing N availability due to atmospheric deposition would increase photosynthetic capacity, foliar N, and specific leaf area (SLA) of bog shrubs. We measured photosynthesis, foliar chemistry and leaf morphology in three ericaceous shrubs (Vaccinium myrtilloides, Ledum groenlandicum and Chamaedaphne calyculata) in a long-term fertilization experiment at Mer Bleue bog, Ontario, Canada, with a background deposition of 0.8 g N m(-2) a(-1). While biomass and chlorophyll concentrations increased in the highest nutrient treatment for C. calyculata, we found no change in the rates of light-saturated photosynthesis (A(max)), carboxylation (V(cmax)), or SLA with nutrient (N with and without PK) addition, with the exception of a weak positive correlation between foliar N and A(max) for C. calyculata, and higher V(cmax) in L. groenlandicum with low nutrient addition. We found negative correlations between photosynthetic N use efficiency (PNUE) and foliar N, accompanied by a species-specific increase in one or more amino acids, which may be a sign of excess N availability and/or a mechanism to reduce ammonium (NH(4)) toxicity. We also observed a decrease in foliar soluble Ca and Mg concentrations, essential minerals for plant growth, but no change in polyamines, indicators of physiological stress under conditions of high N accumulation. These results suggest that plants adapted to low-nutrient environments do not shift their resource allocation to photosynthetic processes, even after reaching N sufficiency, but instead store the excess N in organic compounds for future use. In the long term, bog species may not be able to take advantage of elevated nutrients, resulting in them being replaced by species that are better adapted to a higher nutrient environment.

  16. Effect of mineral constituents in the bioleaching of uranium from uraniferous sedimentary rock samples, Southwestern Sinai, Egypt.

    PubMed

    Amin, Maisa M; Elaassy, Ibrahim E; El-Feky, Mohamed G; Sallam, Abdel Sattar M; Talaat, Mona S; Kawady, Nilly A

    2014-08-01

    Bioleaching, like Biotechnology uses microorganisms to extract metals from their ore materials, whereas microbial activity has an appreciable effect on the dissolution of toxic metals and radionuclides. Bioleaching of uranium was carried out with isolated fungi from uraniferous sedimentary rocks from Southwestern Sinai, Egypt. Eight fungal species were isolated from different grades of uraniferous samples. The bio-dissolution experiments showed that Aspergillus niger and Aspergillus terreus exhibited the highest leaching efficiencies of uranium from the studied samples. Through monitoring the bio-dissolution process, the uranium grade and mineralogic constituents of the ore material proved to play an important role in the bioleaching process. The tested samples asserted that the optimum conditions of uranium leaching are: 7 days incubation time, 3% pulp density, 30 °C incubation temperature and pH 3. Both fungi produced the organic acids, namely; oxalic, acetic, citric, formic, malonic, galic and ascorbic in the culture filtrate, indicating an important role in the bioleaching processes.

  17. Lithogenic, oceanic and anthropogenic sources of atmospheric Sb to a maritime blanket bog, Myrarnar, Faroe Islands.

    PubMed

    Shotyk, William; Chen, Bin; Krachler, Michael

    2005-12-01

    Antimony concentrations were measured in a core collected from Myrarnar, a blanket bog on the Faroe Islands which has been accumulating peat for more than six thousand years. The vertical distribution of Sb indicates that it has been supplied to the peat exclusively from the atmosphere. Despite the proximity to the ocean, the contribution of Sb to the peat from marine aerosols amounts to less than ca. 10% of the natural inputs. Although the peat core contains four notable layers of volcanic ash originating from Iceland, these have not contributed significantly to the Sb inventory. However, the distribution of Sb closely resembles that of Pb, with most of the Sb found in peats dating from the industrial period. Peat samples dating from the Roman Period are not only contaminated with Pb, but also with Sb. Lead is known to be immobile in peat bogs, and in Europe has been derived predominantly from industrial sources for thousands of years. The correlation between Sb and Pb in the peat core from the Faroe Islands supports the hypothesis that Sb is also effectively immobile in peat, and that ombrotrophic bogs are faithful archives of atmospheric Sb deposition. The data presented here also reinforces the view that natural Sb inputs during the past two centuries are dwarfed by industrial inputs, and that human activities have affected the atmospheric Sb cycle to a comparable extent to that of Pb. The natural rate of atmospheric Sb deposition recorded by the peat core (0.33 microg m(-2) year(-1)) is remarkably similar to the value obtained from a Swiss peat bog (Etang de la Gruère) in the samples dating from ca. 6000 to 9000 years ago (0.35 microg m(-2) year(-1)) which suggests that the background rates obtained from the peat cores have broader validity. Consistent with previous work, the data from the Faroe Islands suggests that the natural flux of Sb to the global atmosphere may have been overestimated by a factor of ten, and that the influence of human activities has

  18. Hydrologic conditions in Connors Bog Area, Anchorage, Alaska

    USGS Publications Warehouse

    Glass, R.L.

    1986-01-01

    Connors Bog is a wetland in Anchorage, Alaska, which provides a habitat for many wildlife species and is a popular area for driving off-road vehicles. A landfill, and residential and commercial developments are present in areas which were once wetland. The main source of water is precipitation, which averages about 15 in/yr. Estimates of evapotranspiration, which is the main component of water outflow, range from 10 to 20 in/yr. Minor amounts of groundwater and surface runoff flow into the area from the northeast and southwest and flow out of the area to the northwest and south. Within the wetland, water in peat and sand is unconfined and becomes more mineralized with depth. A leachate beneath and near an abandoned landfill is characterized by concentrations of dissolved solids, dissolved chloride, and total organics that are higher than those of the area 's natural water. The maximum lateral extent of detectable contamination in 1984 was < 500 ft from the landfill 's edge. Water in glacial deposits that underlie a poorly permeable layer of silt and clay is confined. A well completed in this confined aquifer yielded water that had a low concentration of dissolved solids, 150 mg/L. The potentiometric surface of this aquifer was about 20 ft lower than the water table during 1984. Connors Lake occupies a depression that extends below adjacent groundwater levels. The 40-acre lake has a maximum depth of about 9 ft and a low rate of biological production. The quality of water in the lake has not been adversely impacted by nearby residential development or landfill operations. Lake levels appear to be influenced by precipitation and adjacent groundwater levels. (Author 's abstract)

  19. Significant nonsymbiotic nitrogen fixation in Patagonian ombrotrophic bogs.

    PubMed

    Knorr, Klaus-Holger; Horn, Marcus A; Borken, Werner

    2015-06-01

    Nitrogen (N) nutrition in pristine peatlands relies on the natural input of inorganic N through atmospheric deposition or biological dinitrogen (N2 ) fixation. However, N2 fixation and its significance for N cycling, plant productivity, and peat buildup are mostly associated with the presence of Sphagnum mosses. Here, we report high nonsymbiotic N2 -fixation rates in two pristine Patagonian bogs with diversified vegetation and natural N deposition. Nonsymbiotic N2 fixation was measured in samples from 0 to 10, 10 to 20, and 40 to 50 cm depth using the (15) N2 assay as well as the acetylene reduction assay (ARA). The ARA considerably underestimated N2 fixation and can thus not be recommended for peatland studies. Based on the (15) N2 assay, high nonsymbiotic N2 -fixation rates of 0.3-1.4 μmol N2  g(-1)  day(-1) were found down to 50 cm under micro-oxic conditions (2 vol.%) in samples from plots covered by Sphagnum magellanicum or by vascular cushion plants, latter characterized by dense and deep aerenchyma roots. Peat N concentrations point to greater potential of nonsymbiotic N2 fixation under cushion plants, likely because of the availability of easily decomposable organic compounds and oxic conditions in the rhizosphere. In the Sphagnum plots, high N2 fixation below 10 cm depth rather reflects the potential during dry periods or low water level when oxygen penetrates the top peat layer and triggers peat mineralization. Natural abundance of the (15) N isotope of live Sphagnum (5.6 δ‰) from 0 to 10 cm points to solely N uptake from atmospheric deposition and nonsymbiotic N2 fixation. A mean (15) N signature of -0.7 δ‰ of peat from the cushion plant plots indicates additional N supply from N mineralization. Our findings suggest that nonsymbiotic N2 fixation overcomes N deficiency in different vegetation communities and has great significance for N cycling and peat accumulation in pristine peatlands.

  20. Soil data for a collapse-scar bog chronosequence in Koyukuk Flats National Wildlife Refuge, Alaska, 2008

    USGS Publications Warehouse

    O’Donnell, Jonathan A.; Harden, Jennifer W.; Manies, Kristen L.; Jorgenson, M. Torre

    2012-01-01

    Peatlands in the northern permafrost region store large amounts of organic carbon, most of which is currently stored in frozen peat deposits. Recent warming at high-latitudes has accelerated permafrost thaw in peatlands, which will likely result in the loss of soil organic carbon from previously frozen peat deposits to the atmosphere. Here, we report soil organic carbon inventories, soil physical data, and field descriptions from a collapse-scar bog chronosequence located in a peatland ecosystem at Koyukuk Flats National Wildlife Refuge in Alaska.

  1. Vegetation feedbacks of nutrient addition lead to a weaker carbon sink in an ombrotrophic bog.

    PubMed

    Larmola, Tuula; Bubier, Jill L; Kobyljanec, Christine; Basiliko, Nathan; Juutinen, Sari; Humphreys, Elyn; Preston, Michael; Moore, Tim R

    2013-12-01

    To study vegetation feedbacks of nutrient addition on carbon sequestration capacity, we investigated vegetation and ecosystem CO2 exchange at Mer Bleue Bog, Canada in plots that had been fertilized with nitrogen (N) or with N plus phosphorus (P) and potassium (K) for 7-12 years. Gross photosynthesis, ecosystem respiration, and net CO2 exchange were measured weekly during May-September 2011 using climate-controlled chambers. A substrate-induced respiration technique was used to determine the functional ability of the microbial community. The highest N and NPK additions were associated with 40% less net CO2 uptake than the control. In the NPK additions, a diminished C sink potential was due to a 20-30% increase in ecosystem respiration, while gross photosynthesis rates did not change as greater vascular plant biomass compensated for the decrease in Sphagnum mosses. In the highest N-only treatment, small reductions in gross photosynthesis and no change in ecosystem respiration led to the reduced C sink. Substrate-induced microbial respiration was significantly higher in all levels of NPK additions compared with control. The temperature sensitivity of respiration in the plots was lower with increasing cumulative N load, suggesting more labile sources of respired CO2 . The weaker C sink potential could be explained by changes in nutrient availability, higher woody : foliar ratio, moss loss, and enhanced decomposition. Stronger responses to NPK fertilization than to N-only fertilization for both shrub biomass production and decomposition suggest that the bog ecosystem is N-P/K colimited rather than N-limited. Negative effects of further N-only deposition were indicated by delayed spring CO2 uptake. In contrast to forests, increased wood formation and surface litter accumulation in bogs seem to reduce the C sink potential owing to the loss of peat-forming Sphagnum.

  2. Mineralogy and geochemistry of a uraniferous coal from the Red Desert Area, Sweetwater County, Wyoming

    USGS Publications Warehouse

    Breger, Irving A.; Deul, Maurice; Meyrowitz, Robert; Rubinstein, Samuel

    1953-01-01

    A sample of subbituminous uraniferous coal from the Red Desert, Sweetwater County, Wyo., was studied mineralogically. The coal contains gypsum (6 percent), kaolinite (1 percent), quartz (0.3 percent), calcite (trace), and limonite (trace). This suite of minerals and the absence of pyrite show that the coal has been subjected to weathering and oxidation. No uranium minerals have been found; mechanical fractionation has indicated that the uranium is associated with the organic constituents of the coal. The minerals that have been isolated contain 0.0006 percent uranium, a content which is to be expected for nonuraniferous sedimentary rocks. The organic components of the coal contain approximately 0.002 percent uranium. On the basis of material balance calculations, the organic components carry 98 percent of the uranium in the coal. Fischer assays of this weathered coal from the Red Desert indicate a yield of 16.7 gallons of tar per ton on low-temperature retorting. In view of the large reserve of subbituminous coal in the Red Desert, its probable ease of mining, and its tar yield, it may be desirable to carry out further evaluation of the coal as a fuel or raw material for the manufacture of tar or chemicals. If economic factors permit utilization of the coal, the uranium, although present in small percentages, could be recovered as a byproduct.

  3. Holocene Landscape Dynamics in the Ammer Rv. Catchment (Bavarian Alps) - Influence of extreme weather events and land use on soil erosion using peat bogs as geoarchives

    NASA Astrophysics Data System (ADS)

    Schwindt, Daniel; Manthe, Pierre; Völkel, Jörg

    2016-04-01

    Soil degradation and the loss of soil organic carbon (SOC) induced by erosion events significantly influence soils and fertility as parts of the ecosystem services and play an important role with regard to global carbon dynamics. Soil erosion is strongly correlated with anthropogenic land use since the Neolithic Revolution around 8.000 BP. Likewise the effect of extreme weather events on soil erosion is of great interest with regard to the recent climate change debate, predicting a strong increase of extreme weather events. Aim of this study is the reconstruction of the Holocene landscape dynamic as influenced by land use and climate conditions. In this study peat bogs containing layers of colluvial sediments directly correlated to soil erosion were used as geoarchives for landscape dynamics. A temporal classification of extreme erosion events was established by dating organic material via 14C within both, colluvial layers as well as their direct peat surroundings. Detection and characterization of peat bogs containing colluvial sediments was based on geomorphological mapping, the application of geophysical methods (ERT - electrical resistivity tomography, GPR - ground penetrating radar) and core soundings. Laboratory analysis included the analysis of particle sizes and the content of organic material. We investigated 16 peat bogs following the altitudinal gradient of the Ammer River from alpine and subalpine towards lowland environments. A deposition of colluvial material could be detected in 4 peat bogs, all situated in the lower parts of the catchment. The minerogenic entry into peat bogs occurred throughout the Holocene as revealed by radiocarbon dating. A distinct cluster of erosional events e.g. during the little ice age could not be detected. Therefore, soil erosion dynamics and the appearance of colluvial sediments within peat bogs must rather be regarded as an effect of land use, actually farming and crop cultivation, or small-scale morphodynamic like

  4. Tracing of ca 800 yr old mining activity in peat bog using Pb elemental concentrations and isotope compositions.

    NASA Astrophysics Data System (ADS)

    Baron, S.; Carignan, J.; Ploquin, A.

    2003-04-01

    Sixty sites of slags have been documented on the Mont-Lozère in southern France. The petrographic analysis shows that slags are metallurgical wastes (800 to 850 yr BP) which certainly result from smelting activity for lead and silver extraction (Ploquin et al., 2001). The aims of this study are: 1) to trace the source of Pb ores which supplied the smelting sites, by using the Pb isotopic composition of several surrounding Pb deposits, 2) to evaluate the actual pollution caused by these slags, by using elemental and isotopic compositions of soils, water and vegetation, and 3) to document the pollution history of the region, by using elemental and isotopic compositions of peat bog cores collected in the neighbourhood of the historical smelting sites. The lead isotopic composition of galena collected in most surrounding ores is very similar to that of different slag samples. On the other hand, the high precision of the results allowed us to select the mineralised areas which were probably the ore sources. The Pb isotopic composition of slags is even more homogeneous: 208/206 Pb: 2.092±0.002; 206/207 Pb: 1.179±0.001; 208/204 Pb: 38.663±0.025; 207/204 Pb: 15.665±0.006; 206/204 Pb: 18.476±0.023, and will allow source tracing in the environment. The "Narses Mortes" peat bog, around which two smelting sites have been reported, is strongly minerotrophic and contains 8 to 60% ash. A 1.40 m core have been retrieved and divided into 58 individual samples. Minerotrophic peat bog records both atmospheric deposition, soils leaching and the grounwater influence. The measured metal concentrations are normalised to Al contents of peat bog samples and the metal/Al ratios are compared to that of the Mont-Lozère granite: relative excess in metal concentrations are found in peat bog samples. An increasing excess of most metals (Pb, Zn, Cd...) was measured for surface samples, from 55 cm depth to the top of the core (23 cm depth). This profil might be attributed to atmospheric

  5. Environmental assessment of remedial action at the inactive uraniferous lignite processing sites at Belfield and Bowman, North Dakota. [UMTRA Project

    SciTech Connect

    Beranich, S.; Berger, N.; Bierley, D.; Bond, T.M.; Burt, C.; Caldwell, J.A.; Dery, V.A.; Dutcher, A.; Glover, W.A.; Heydenburg, R.J.; Larson, N.B.; Lindsey, G.; Longley, J.M.; Millard, J.B.; Miller, M.; Peel, R.C.; Persson-Reeves, C.H.; Titus, F.B.; Wagner, L.

    1989-09-01

    The Uranium Mill Tailings Radiation Control Act of 1978 (UMTRCA), to clean up the Belfield and Bowman, North Dakota, uraniferous lignite processing sites to reduce the potential health impacts associated with the residual radioactive materials remaining at these sites. Remedial action at these sites must be performed in accordance with the US Environmental Protection Agency's (EPA) standards promulgated for the remedial action and with the concurrence of the US Nuclear Regulatory Commission (NRC) and the state of North Dakota. The inactive Belfield uraniferous lignite processing site is one mile southeast of Belfield, North Dakota. The inactive Bowman uraniferous lignite processing site at the former town of Griffin, is seven miles northwest of Bowman, North Dakota and 65 road miles south of Belfield. Lignite ash from the processing operations has contaminated the soils over the entire 10.7-acre designated Belfield site and the entire 12.1-acre designated Bowman site. Dispersion of the ash has contaminated an additional 20.6 acres surrounding the Belfield processing site and an additional 59.2 acres surrounding the Bowman processing site. The proposed remedial action is to relocate the contaminated materials at the Belfield processing site to the Bowman processing/disposal site for codisposal with the Bowman contaminated soils. The environmental impacts assessed in this EA were evaluated for the proposed remedial action and the no action alternative and demonstrate that the proposed action would not significantly affect the quality of the human environment and would be performed in compliance with applicable environmental laws. The no action alternative would not be consistent with the intent of Public Law 95-604 and would not comply with the EPA standards. 48 refs., 10 figs., 7 tabs.

  6. Nutrient availability at Mer Bleue bog measured by PRSTM probes

    NASA Astrophysics Data System (ADS)

    Wang, M.; Moore, T. R.; Talbot, J.

    2015-12-01

    Bogs, covering ~0.7 million km2 in Canada, store a large amount of C and N. As nutrient deficient ecosystems, it's critical to examine the nutrient availabilities and seasonal dynamics. We used Plant Root Simulators (PRSTM) at Mer Bleue bog to provide some baseline data on nutrient availability and its variability. In particular, we focused on ammonium, nitrate, phosphate, calcium, magnesium and potassium, iron, sulphate and aluminum. We placed PRS probes at a depth of 5 - 15 cm in pristine plots and plots with long term N, P and K fertilization for 4 weeks and determined the availability of these nutrients, from spring through to fall. Probes were also placed beneath the water table in hummock and hollow microtopography and along a transect including part of the bog which had been drained through the creation of a ditch 80 years ago. The result showed that there was limited available ammonium, nitrate and phosphate in the bog, the seasonal variation of nutrient availabilities probably due to mineralization, an increase in the availability of some nutrients between different water table depths or as a result of drainage, and the relative availability of nutrients compared to the input from fertilization. We suggest that PRS probes could be a useful tool to examine nutrient availability and dynamics in wetlands, with careful consideration of installing condition, for example, proper exposure period, depth relative to water table etc.

  7. Radionuclide release from simulated waste material after biogeochemical leaching of uraniferous mineral samples.

    PubMed

    Williamson, Aimee Lynn; Caron, François; Spiers, Graeme

    2014-12-01

    Biogeochemical mineral dissolution is a promising method for the released of metals in low-grade host mineralization that contain sulphidic minerals. The application of biogeochemical mineral dissolution to engineered leach heap piles in the Elliot Lake region may be considered as a promising passive technology for the economic recovery of low grade Uranium-bearing ores. In the current investigation, the decrease of radiological activity of uraniferous mineral material after biogeochemical mineral dissolution is quantified by gamma spectroscopy and compared to the results from digestion/ICP-MS analysis of the ore materials to determine if gamma spectroscopy is a simple, viable alternative quantification method for heavy nuclides. The potential release of Uranium (U) and Radium-226 ((226)Ra) to the aqueous environment from samples that have been treated to represent various stages of leaching and passive closure processes are assessed. Dissolution of U from the solid phase has occurred during biogeochemical mineral dissolution in the presence of Acidithiobacillus ferrooxidans, with gamma spectroscopy indicating an 84% decrease in Uranium-235 ((235)U) content, a value in accordance with the data obtained by dissolution chemistry. Gamma spectroscopy data indicate that only 30% of the (226)Ra was removed during the biogeochemical mineral dissolution. Chemical inhibition and passivation treatments of waste materials following the biogeochemical mineral dissolution offer greater protection against residual U and (226)Ra leaching. Pacified samples resist the release of (226)Ra contained in the mineral phase and may offer more protection to the aqueous environment for the long term, compared to untreated or inhibited residues, and should be taken into account for future decommissioning. PMID:24726552

  8. Oribatid mite species numbers increase, densities decline and parthenogenetic species suffer during bog degradation.

    PubMed

    Seniczak, Anna; Seniczak, Stanisław; Maraun, Mark; Graczyk, Radomir; Mistrzak, Marcin

    2016-04-01

    This study compared the oribatid mites in two natural and four industrially exploited bogs. One natural bog (Zakręt, Z) was located in northeastern Poland and the other one (Toporowy Staw Niżni, TSN), in southern Poland. The four exploited bogs were also located in southern Poland and can be ranked from least to most degraded as follows: Łysa Puścizna (LP), Baligówka (B), Puścizna Mała (PM) and Kaczmarka (K). In the natural bogs, the water pH was higher than in the degraded ones, but other parameters were lower (conductivity, colour value, oxygen demand, and concentration of chlorides). In the natural bogs, the Oribatida were highly abundant (average density was 169,100 ind./m(2)), but with low species diversity and one dominating species. In bog Z the most abundant was Limnozetes foveolatus that had dominance of 75 % and in bog TSN, located at higher altitude, Trimalaconothrus maior dominated (73 %). In two degraded bogs that had still good water conditions (LP and B) the oribatid communities resembled those from the natural bogs; in LP the most abundant species was Hydrozetes lacustris and in bog B, L. foveolatus. In contrast, in two more degraded bogs (PM and K) the abundance of mites was lower (average density was 17,850 ind./m(2)), species diversity of the Oribatida was higher, and no species achieved a high dominance like in the natural bogs. Additionally, in more degraded bogs the abundance of parthenogenetic species was lower than in the natural bogs.

  9. Predominant anthropogenic sources and rates of atmospheric mercury accumulation in southern Ontario recorded by peat cores from three bogs: comparison with natural "background" values (past 8000 years).

    PubMed

    Givelet, Nicolas; Roos-Barraclough, Fiona; Shotyk, William

    2003-12-01

    Peat cores from three bogs in southern Ontario provide a complete, quantitative record of net rates of atmospheric Hg accumulation since pre-industrial times. For comparison with modern values, a peat core extending back 8000 years was used to quantify the natural variations in Hg fluxes for this region, and their dependence on climatic change and land use history. The net mercury accumulation rates were separated into "natural" and "excess" components by comparing the Hg/Br ratios of modern samples with the long-term, pre-anthropogenic average Hg/Br. The average background mercury accumulation rate during the pre-anthropogenic period (from 5700 years BC to 1470 AD) was 1.4 +/- 1.0 microg m(-2) per year (n = 197). The beginning of Hg contamination from anthropogenic sources dates from AD 1475 at the Luther Bog, corresponding to biomass burning for agricultural activities by Native North Americans. During the late 17th and 18th centuries, deposition of anthropogenic Hg was at least equal to that of Hg from natural sources. Anthropogenic inputs of Hg to the bogs have dominated continuously since the beginning of the 19th century. The maximum Hg accumulation rates decrease in the order Sifton Bog, in the City of London, Ontario (141 microg Hg m(-2) per year), Luther Bog in an agricultural region (89 microg Hg m(-2) per year), and Spruce Bog which is in a comparatively remote, forested region (54 microg Hg m(-2) per year). Accurate age dating of recent peat samples using the bomb pulse curve of 14C shows that the maximum rate of atmospheric Hg accumulation occurred during AD 1956 and 1959 at all sites. In these (modern) samples, the Hg concentration profiles resemble those of Pb, an element which is known to be immobile in peat bogs. The correlation between these two metals, together with sulfur, suggests that the predominant anthropogenic source of Hg (and Pb) was coal burning. While Hg accumulation rates have gone into strong decline since the late 1950's, Hg

  10. Dynamics of biochemical processes and redox conditions in geochemically linked landscapes of oligotrophic bogs

    NASA Astrophysics Data System (ADS)

    Inisheva, L. I.; Szajdak, L.; Sergeeva, M. A.

    2016-04-01

    The biological activity in oligotrophic peatlands at the margins of the Vasyugan Mire has been studied. It is shown found that differently directed biochemical processes manifest themselves in the entire peat profile down to the underlying mineral substrate. Their activity is highly variable. It is argued that the notion about active and inert layers in peat soils is only applicable for the description of their water regime. The degree of the biochemical activity is specified by the physical soil properties. As a result of the biochemical processes, a micromosaic aerobic-anaerobic medium is developed under the surface waterlogged layer of peat deposits. This layer contains the gas phase, including oxygen. It is concluded that the organic and mineral parts of peat bogs represent a single functional system of a genetic peat profile with a clear record of the history of its development.

  11. Baseline risk assessment of ground water contamination at the inactive uraniferous lignite ashing site near Bowman, North Dakota

    SciTech Connect

    Not Available

    1994-11-01

    This baseline risk assessment of ground water contamination at the inactive uraniferous lignite ashing site near Bowman, North Dakota, evaluates the potential impacts to public health or the environment from contaminated ground water at this site. This contamination is a result of the uraniferous lignite ashing process, when coal containing uranium was burned to produce uranium. Potential risk is quantified only for constituents introduced by the processing activities and not for the constituents naturally occurring in background ground water in the site vicinity. Background ground water, separate from any site-related contamination, imposes a percentage of the overall risk from ground water ingestion in the Bowman site vicinity. The US Department of Energy (DOE) Uranium Mill Tailings Remedial Action (UMTRA) Project is developing plans to address soil and ground water contamination at the site. The UMTRA Surface Project involves the determination of the extent of soil contamination and design of an engineered disposal cell for long-term storage of contaminated materials. The UMTRA Ground Water Project evaluates ground water contamination. Based on results from future site monitoring activities as defined in the site observational work plan and results from this risk assessment, the DOE will propose an approach for managing contaminated ground water at the Bowman site.

  12. Effect of mineral constituents in the bioleaching of uranium from uraniferous sedimentary rock samples, Southwestern Sinai, Egypt.

    PubMed

    Amin, Maisa M; Elaassy, Ibrahim E; El-Feky, Mohamed G; Sallam, Abdel Sattar M; Talaat, Mona S; Kawady, Nilly A

    2014-08-01

    Bioleaching, like Biotechnology uses microorganisms to extract metals from their ore materials, whereas microbial activity has an appreciable effect on the dissolution of toxic metals and radionuclides. Bioleaching of uranium was carried out with isolated fungi from uraniferous sedimentary rocks from Southwestern Sinai, Egypt. Eight fungal species were isolated from different grades of uraniferous samples. The bio-dissolution experiments showed that Aspergillus niger and Aspergillus terreus exhibited the highest leaching efficiencies of uranium from the studied samples. Through monitoring the bio-dissolution process, the uranium grade and mineralogic constituents of the ore material proved to play an important role in the bioleaching process. The tested samples asserted that the optimum conditions of uranium leaching are: 7 days incubation time, 3% pulp density, 30 °C incubation temperature and pH 3. Both fungi produced the organic acids, namely; oxalic, acetic, citric, formic, malonic, galic and ascorbic in the culture filtrate, indicating an important role in the bioleaching processes. PMID:24682031

  13. Mid- and late Holocene human impact recorded by the Coltrondo peat bog (NE Italian Alps)

    NASA Astrophysics Data System (ADS)

    Segnana, Michela; Poto, Luisa; Gabrieli, Jacopo; Martino, Matteo; Oeggl, Klaus; Barbante, Carlo

    2016-04-01

    Peat bogs are ideal archives for the study of environmental changes, whether these are natural or human induced. Indeed, receiving water and nutrients exclusively from dry and wet atmospheric depositions, they are among the most suitable matrices for palaeoenvironmental reconstruction. The present study is focused on the Eastern sector of the Italian Alps, where we sampled the Coltrondo peat bog, in the Comelico area (ca. 1800 m a.s.l.) The knowledge of the human history in this area is rather scarce: the only pieces of archaeological evidence found in this area dates back to the Mesolithic and the absence of later archaeological finds makes it difficult to reconstruct the human settlement in the valley. With the main aim to obtain information about the human settlement in that area we selected a multi-proxy approach, combining the study of biotic and abiotic sedimentary components archived in the 7900 years-peat bog record. Pollen analysis is performed along the core registering human impacts on the area from ca. 2500 cal BP, when land-use changes are well evidenced by the presence of human-related pollen and non-pollen palynomorphs (NPPs), as well as by the increase in micro-charcoal particles. Periods of increased human impact are recorded at the end of the Middle Ages and later, at the end of the 19th century. The analysis of trace elements, such as lead, is performed by means of ICP-MS technique and its enrichment factor (EF) is calculated. A first slight increase of Pb EF during Roman Times is possibly related to mining activities carried out by the Romans. Mining activities carried out in the area are registered during the Middle Ages, while the advent of the industrialization in the 20th century is marked by the highest EF values registered on the top of the core. To help and support the interpretation of geochemical data, lead isotopes ratios are also measured using ICP-MS to discriminate between natural and anthropogenic sources of lead. The 206Pb/207Pb

  14. Uranium accumulation in aquatic macrophytes in an uraniferous region: Relevance to natural attenuation.

    PubMed

    Cordeiro, Cristina; Favas, Paulo J C; Pratas, João; Sarkar, Santosh Kumar; Venkatachalam, Perumal

    2016-08-01

    Phytoremediation potential of uranium (U) was investigated by submerged, free-floating and rooted emergent native aquatic macrophytes inhabiting along the streams of Horta da Vilariça, a uraniferous geochemical region of NE Portugal. The work has been undertaken with the following objectives: (i) to relate the U concentrations in water-sediment-plant system; and (ii) to identify the potentialities of aquatic plants to remediate U-contaminated waters based on accumulation pattern. A total of 25 plant species culminating 233 samples was collected from 15 study points along with surface water and contiguous sediments. Concentrations of U showed wide range of variations both in waters (0.61-5.56 μg L(-1), mean value 1.98 μg L(-1)) and sediments (124-23,910 μg kg(-1), mean value 3929 μg kg(-1)) and this is also reflected in plant species examined. The plant species exhibited the ability to accumulate U several orders of magnitude higher than the surrounding water. Maximum U concentrations was recorded in the bryophyte Scorpiurium deflexifolium (49,639 μg kg(-1)) followed by Fontinalis antipyretica (35,771 μg kg(-1)), shoots of Rorippa sylvestris (33,837 μg kg(-1)), roots of Oenanthe crocata (17,807 μg kg(-1)) as well as in Nasturtium officinale (10,995 μg kg(-1)). Scorpiurium deflexifolium displayed a high bioconcentration factor (BF) of ∼2.5 × 10(4) (mean value). The species Fontinalis antipyretica, Nasturtium officinale (roots) and Rorippa sylvestris (shoots) exhibited the mean BFs of 1.7 × 10(4), 5 × 10(3) and 4.8 × 10(3) respectively. Maximum translocation factor (TF) was very much pronounced in the rooted perennial herb Rorippa sylvestris showing extreme ability to transport U for the shoots and seems to be promising candidate to be used as bioindicator species. PMID:27164268

  15. Uranium accumulation in aquatic macrophytes in an uraniferous region: Relevance to natural attenuation.

    PubMed

    Cordeiro, Cristina; Favas, Paulo J C; Pratas, João; Sarkar, Santosh Kumar; Venkatachalam, Perumal

    2016-08-01

    Phytoremediation potential of uranium (U) was investigated by submerged, free-floating and rooted emergent native aquatic macrophytes inhabiting along the streams of Horta da Vilariça, a uraniferous geochemical region of NE Portugal. The work has been undertaken with the following objectives: (i) to relate the U concentrations in water-sediment-plant system; and (ii) to identify the potentialities of aquatic plants to remediate U-contaminated waters based on accumulation pattern. A total of 25 plant species culminating 233 samples was collected from 15 study points along with surface water and contiguous sediments. Concentrations of U showed wide range of variations both in waters (0.61-5.56 μg L(-1), mean value 1.98 μg L(-1)) and sediments (124-23,910 μg kg(-1), mean value 3929 μg kg(-1)) and this is also reflected in plant species examined. The plant species exhibited the ability to accumulate U several orders of magnitude higher than the surrounding water. Maximum U concentrations was recorded in the bryophyte Scorpiurium deflexifolium (49,639 μg kg(-1)) followed by Fontinalis antipyretica (35,771 μg kg(-1)), shoots of Rorippa sylvestris (33,837 μg kg(-1)), roots of Oenanthe crocata (17,807 μg kg(-1)) as well as in Nasturtium officinale (10,995 μg kg(-1)). Scorpiurium deflexifolium displayed a high bioconcentration factor (BF) of ∼2.5 × 10(4) (mean value). The species Fontinalis antipyretica, Nasturtium officinale (roots) and Rorippa sylvestris (shoots) exhibited the mean BFs of 1.7 × 10(4), 5 × 10(3) and 4.8 × 10(3) respectively. Maximum translocation factor (TF) was very much pronounced in the rooted perennial herb Rorippa sylvestris showing extreme ability to transport U for the shoots and seems to be promising candidate to be used as bioindicator species.

  16. Geochemical and mineralogical composition of bog iron ore as a resource for prehistoric iron production - A case study of the Widawa catchment area in Eastern Silesia, Poland

    NASA Astrophysics Data System (ADS)

    Thelemann, Michael; Bebermeier, Wiebke; Hoelzmann, Philipp

    2016-04-01

    Spreading from the Near East in the declining Bronze Age from the 2nd millennium BCE onwards, the technique of iron smelting reached Eastern Silesia, Poland, in approximately the 2nd century BCE (pre-Roman Iron Age). At this time the region of the Widawa catchment area was inhabited by the Przeworsk culture. While the older moraine landscape of the study area lacks ores from geological rock formations, bog iron ores were relatively widespread and, due to their comparatively easy accessibility, were commonly exploited for early iron production. In this poster the mineralogical and elemental composition of local bog iron ore deposits and iron slag finds, as a by-product of the smelting process, are investigated. The crystalline mineralogical composition of local bog iron ores is dominated by quartz (SiO2) and goethite (α FeO(OH)), in contrast to slag samples in which fayalite (Fe2SiO4), wüstite (FeO) and quartz, with traces of goethite, represent the main minerals. Ores and slags are both characterized by notable hematite (Fe2O3), magnetite (Fe3O4) and maghemite (γ-Fe2O3) contents. Analyzed bog iron ore samples show iron contents of up to 64.9 mass% Fe2O3 (45.4 mass% Fe), whereas the iron contents of bloomery slags vary between 48.7 and 72.0 mass% FeO (37.9 and 56.0 mass% Fe). A principal component analysis of the element contents, which were quantified by portable energy-dispersive X-ray fluorescence spectrometry (p-ED-XRF), indicates local variations in the elemental composition. Our results show that bog iron ores are relatively widely distributed with spatially varying iron contents along the Widawa floodplain but present-day formation conditions (e.g. different ground-water levels) are negatively affected by modern land-use practices, such as agriculture and melioration measures.

  17. Bog bilberry phenolics, antioxidant capacity and nutrient profile.

    PubMed

    Colak, Nesrin; Torun, Hülya; Gruz, Jiri; Strnad, Miroslav; Hermosín-Gutiérrez, Isidro; Hayirlioglu-Ayaz, Sema; Ayaz, Faik Ahmet

    2016-06-15

    Phenolics and nutrient profiles of bog bilberry (Vaccinium uliginosum L.) collected from high mountain pastures in northeast Anatolia (Turkey) were examined for the first time in this study. The major soluble sugar identified in the berry was fructose, following by glucose, and the main organic acid identified was citric acid, followed by malic acid. Eleven phenolic acids and 17 anthocyanin 3-glycosides were identified and quantified. Caffeic acid in the free and glycoside forms and syringic acid in the ester form were the major phenolic acids, and the major individual anthocyanin present in the berry was malvidin 3-glucoside (24%). The highest total phenolics and anthocyanin contents were obtained from the anthocyanin fraction in conjunction with the highest antioxidant capacity, followed by the polyphenolic and aqueous fractions, FRAP, ORAC and DPPH, in that order. Our findings can be used to compare bog bilberry with other Vaccinium berries and to help clarify the relative potential health benefits of different berries.

  18. Properties and structure of raised bog peat humic acids

    NASA Astrophysics Data System (ADS)

    Klavins, Maris; Purmalis, Oskars

    2013-10-01

    Humic substances form most of the organic components of soil, peat and natural waters, and their structure and properties differ very much depending on their source. The aims of this study are to characterize humic acids (HAs) from raised bog peat, to evaluate the homogeneity of peat HAs within peat profiles, and to study peat humification impact on properties of HAs. A major impact on the structure of peat HAs have lignin-free raised bog biota (dominantly represented by bryophytes of different origin). On diagenesis scale, peat HAs have an intermediate position between the living organic matter and coal organic matter, and their structure is formed in a process in which more labile structures (carbohydrates, amino acids, etc.) are destroyed, while thermodynamically more stable aromatic and polyaromatic structures emerge as a result of abiotic synthesis. However, in comparison with soil, aquatic and other HAs, aromaticity of peat HAs is much lower. Comparatively, the raised bog peat HAs are at the beginning of the transformation process of living organic matter. Concentrations of carboxyl and phenolic hydroxyl groups change depending on the peat age and decomposition degree from where HAs have been isolated, and carboxylic acidity of peat HAs increases with peat depth and humification degree.

  19. Extracting phosphoric iron under laboratorial conditions smelting bog iron ores

    NASA Astrophysics Data System (ADS)

    Török, B.; Thiele, A.

    2013-12-01

    In recent years it has been indicated by archaeometric investigations that phosphoric-iron (P-iron, low carbon steel with 0,5-1,5wt% P), which is an unknown and unused kind of steel in the modern industry, was widely used in different parts of the world in medieval times. In this study we try to explore the role of phosphorus in the arhaeometallurgy of iron and answer some questions regarding the smelting bog iron ores with high P-content. XRF analyses were performed on bog iron ores collected in Somogy county. Smelting experiments were carried out on bog iron ores using a laboratory model built on the basis of previously conducted reconstructed smelting experiments in copies of excavated furnaces. The effect of technological parameters on P-content of the resulted iron bloom was studied. OM and SEM-EDS analyses were carried out on the extracted iron and slag samples. On the basis of the material analyses it can be stated that P-iron is usually extracted but the P-content is highly affected by technological parameters. Typical microstructures of P-iron and of slag could also be identified. It could also be established that arsenic usually solved in high content in iron as well.

  20. Animal and vegetation patterns in natural and man-made bog pools: implications for restoration

    USGS Publications Warehouse

    Mazerolle, M.J.; Poulin, M.; Lavoie, C.; Rochefort, L.; Desrochers, A.; Drolet, B.

    2006-01-01

    1. Peatlands have suffered great losses following drainage for agriculture, forestry, urbanisation, or peat mining, near inhabited areas. We evaluated the faunal and vegetation patterns after restoration of a peatland formerly mined for peat. We assessed whether bog pools created during restoration are similar to natural bog pools in terms of water chemistry, vegetation structure and composition, as well as amphibian and arthropod occurrence patterns. 2. Both avian species richness and peatland vegetation cover at the site increased following restoration. Within bog pools, however, the vegetation composition differed between natural and man-made pools. The cover of low shrubs, Sphagnum moss, submerged, emergent and floating vegetation in man-made pools was lower than in natural pools, whereas pH was higher than in typical bog pools. Dominant plant species also differed between man-made and natural pools. 3. Amphibian tadpoles, juveniles and adults occurred more often in man-made pools than natural bog pools. Although some arthropods, including Coleoptera bog specialists, readily colonised the pools, their abundance was two to 26 times lower than in natural bog pools. Plant introduction in bog pools, at the stocking densities we applied, had no effect on the occurrence of most groups. 4. We conclude that our restoration efforts were partially successful. Peatland-wide vegetation patterns following restoration mimicked those of natural peatlands, but 4 years were not sufficient for man-made pools to fully emulate the characteristics of natural bog pools.

  1. Key plant species and succession patterns associated to past fen-bog transitions - perspective to future

    NASA Astrophysics Data System (ADS)

    Väliranta, Minna; Luoto, Miska; Juutinen, Sari; Korhola, Atte; Tuittila, Eeva-stiina

    2016-04-01

    Minerotrophic fens and ombrotrophic bogs differ in their hydrology, vegetation and carbon dynamics and their geographical distribution seems to be linked to certain climate parameters, such as temperature and effective precipitation. Currently bogs dominate the southern boreal zone but the climate warming with altered temperature and effective precipitation may shift the distribution of bog zone northwards. In this study, we first used plant macrofossil method and radiocarbon analysis to identify and date past fen-bog transitions. These transitions were compared to major Holocene climate phases. Subsequently, palaeoecological data were associated to ecological and environmental data collected along the current fen-bog ecotone in Finland. We identified three successional phases 1) initial minerotrophic fen phase 2) Eriophorum vaginatum-dominated oligotrophic fen phase which was followed by 3) ombrorophic bog phase. Duration of these phases varied but late Holocene timing of fen-bog transition showed some consistency. Based on palaeoecological data 57 % of the modern ecotone peatlands were classified to be in a fen phase, 10 % were in an Eriophorum-dominated phase and 33 % were going through a transition from fen to bog. The study showed that regime shifts are driven by autogenic succession and climate but also fires may efficiently control succession pathways. Our results support the hypothesis that climate change can promote the ombrotrophication process in the southern border of the fen-bog ecotone due to changes in hydrology balance.

  2. Microbial communities and transformation of carbon compounds in bog soils of the taiga zone (Tomsk oblast)

    NASA Astrophysics Data System (ADS)

    Grodnitskaya, I. D.; Trusova, M. Yu.

    2009-09-01

    Two types of bogs were studied in Tomsk oblast—Maloe Zhukovskoe (an eutrophic peat low-moor bog) and Ozernoe (an oligotrophic peat high-moor bog). The gram-negative forms of Proteobacteria were found to be dominant and amounted to more than 40% of the total population of the microorganisms investigated. In the peat bogs, the population and diversity of the hydrolytic microbial complex, especially of the number of micromycetes, were lower than those in the mineral soils. The changes in the quantitative indices of the total microbiological activity of the bogs were established. The microbial biomass and the intensity of its respiration differed and were also related to the depth of the sampling. In the Zhukovskoe peat low-moor bog, the maximal biomass of heterotrophic microorganisms (154 μg of C/g of peat) was found in the aerobic zone at a depth of 0 to 10 cm. In the Ozernoe bog, the maximal biomass was determined in the zone of anaerobiosis at a depth of 300 cm (1947 μ g of C/g of peat). The molecular-genetic method was used for the determination of the spectrum of the methanogens. Seven unidentified dominant forms were revealed. The species diversity of the methanogens was higher in the oligotrophic high-moor bog than in the eutrophic low-moor bog.

  3. Atmospheric supply of trace elements studied by peat samples from ombrotrophic bogs.

    PubMed

    Steinnes, E; Hvatum, O Ø; Bølviken, B; Varskog, P

    2005-01-01

    Concentrations of Fe and 12 trace elements in peat from ombrotrophic bogs were used to estimate the atmospheric deposition of these elements on a temporal and spatial scale. Peat samples were collected at 21 different sites in Norway encompassing large geographical differences in marine influence and air pollution. The study demonstrates that surface peat is an excellent medium to study geographical differences in heavy metal deposition, provided that effects of the surface plant cover are properly considered. Long-range atmospheric transport of pollutants is the main source for As, Cd, Pb, Sb, and Zn, and to a lesser extent for Cu and Se. Biogenic emissions from the ocean appear to be the main source of Se to the peat. The metals Co, Cr, Fe, and Ni are mainly associated with wind-blown local soil dust. Surface enrichment of Mn, and in part Zn, is mainly caused by nutrient circulation between the surface peat and vascular plants growing on it. Deposition of marine salts appears to be the main reason for lower Mn concentrations in the peat near the coast.

  4. Geochemical evidence for the hydrology of a Tamarack-peat bog, Brimfield Township, Portage County, Ohio

    SciTech Connect

    Wilson, T.P.; Miller, L.A. . Dept. of Geology and Water Resources)

    1992-01-01

    Peat Bogs and wetlands represent unique environmental settings what are increasingly subjected to anthropogenic stresses involving inputs of water and chemicals. This study used geochemical and hydrologic monitoring to determine the inputs and fates of elements of the Kent-Brimfield bog located in Portage County, Ohio. Based on physical and chemical information collected over one year, a model is proposed here describing the hydrologic connection between a bog and shallow ground water surrounding the bog. The chemical composition of precipitation, soil water and ground water in the bog vicinity were monitored for one year. Field measurements included water levels, pH, Eh, alkalinity and temperature. Trace metal content of the peat, the pore waters, soil water and ground waters were determined by GFAA, ICP and LIC methods. This bog was found to function as part of a perched water table aquifer. Water in the upper 3 m of the bog is found to be chemically similar to precipitation, but modified by reactions involving dissolution of mineral matter and biologic processes. The chemistry of water deeper in the bog (> 3m) resembles shallow ground water surrounding the bog, modified by weathering of underlying geologic materials and sulfate reduction. This similarity, along with ground water elevations within and outside of the bog, supports that shallow ground water interacts with, and helps maintain water levels in the upper surface of the bog. From these results, a model is proposed for the seasonal variations in hydrologic processes operating in the wetland and surrounding basin, and describes how wetlands may change seasonally from being influent to effluent systems.

  5. Late Holocene ecohydrological and carbon dynamics of a UK raised bog: impact of human activity and climate change

    NASA Astrophysics Data System (ADS)

    Turner, T. Edward; Swindles, Graeme T.; Roucoux, Katherine H.

    2014-01-01

    Understanding the ecohydrological responses of peatlands to climate change is particularly challenging over the late Holocene owing to the confounding influence of anthropogenic activity. To address this, a core spanning the last ˜2400 years from a raised bog in northern England was analysed using a comprehensive suite of proxy methods in an attempt to elucidate the drivers of change. A testate amoebae-based transfer function was used to quantitatively reconstruct changes in water table depth, supported by humification analysis and a plant macrofossil-derived hydroclimatic index. Pollen and plant macrofossil data were used to examine regional and local vegetation change, and human impacts were inferred from charcoal and geochemistry. Chronological control was achieved through a Bayesian age-depth model based on AMS radiocarbon dates and spheroidal carbonaceous particles, from which peat and carbon accumulation rates were calculated. Phases of both increased and decreased bog surface wetness (inferred effective precipitation) are present, with dry phases at c. AD 320-830, AD 920-1190 and AD 1850-present, and a marked period of increased effective precipitation at c. AD 1460-1850. Coherence with other records from across Northern Europe suggests that these episodes are primarily driven by allogenic climatic change. Periods of high bog surface wetness correspond to the Wolf, Spörer and Maunder sunspot activity minima, suggesting solar forcing was a significant driver of climate change over the last ˜1000 years. Following the intensification of agriculture and industry over the last two centuries, the combined climatic and anthropogenic forcing effects become increasingly difficult to separate due to increases in atmospheric deposition of anthropogenically derived pollutants, fertilising compounds, and additions of wind-blown soil dust. We illustrate the need for multiproxy approaches based on high-resolution palaeoecology and geochemistry to examine the recent

  6. Features of water chemical composition of oligotrophic and eutrophic bogs in the South of the Tomsk region

    NASA Astrophysics Data System (ADS)

    Naymushina, O.

    2016-03-01

    On the basis of the actual material the analysis of chemical composition of bog waters in the territory of the South of the Tomsk region is carried out. The data on average concentration of macro and trace components, organic matter, pH of bog waters are obtained. Significant distinctions in a chemical composition of surface water for different types of bogs are revealed. The composition and macrostructure of humic acids by the example of eutrophic bogs is studied.

  7. The bog landforms of continental western Canada in relation to climate and permafrost patterns

    SciTech Connect

    Vitt, D.H.; Halsey, L.A. ); Zoltai, S.C. )

    1994-02-01

    In continental western Canada, discontinuous permafrost is almost always restricted to ombrotrophic peatlands (bogs). Bogs occur mostly as islands or peninsulas in large, often complex fens or are confined to small basins. Permafrost may be present in extensive peat plateaus (or more locally as palsas) and was preceded by a well-developed layer of Sphagnum that served to insulate the peat and lower the pore water temperatures. Air photo interpretation reveals the occurrence of bogs with five types of surface physiography. Concentrated to the south are bogs without internal patterns that have never had permafrost. Dominating the mid-latitudes are bogs with internal lawns and fens with internal lawns (mostly representing former bogs) that had permafrost lenses in the past that have recently degraded. Concentrated in the northwest are peat plateaus without internal lawns or distinct collapse scars, but with permafrost; dominating in the northernmost area are peat plateaus with extensive permafrost and collapse scars. Relationships are apparent between the current - 1[degrees]C isotherm and the southern occurrence of peat plateaus and between the 0[degrees]C isotherm and the southern edge of bogs and fens with internal lawns. We interpret bogs and fens with internal lawns to represent areas where permafrost degradation is currently occurring at a greater rate than aggradation, seemingly in response to warmer regional climate, although fire frequency may also be of local importance. 54 refs., 21 figs., 2 tabs.

  8. Genesis of peat-bog soils in the northern taiga spruce forests of the Kola Peninsula

    SciTech Connect

    Nikonov, V.V.

    1981-01-01

    The characteristics of soil formation processes in the Peat-Bog soils of waterlogged spruce phytocenoses on the Kola Peninsula are investigated. It is found that the ash composition of the peat layer is determined primarily by the composition of the buried plant residues. The effect of the chemical composition of water feeding the peat bogs is determined. (Refs. 7).

  9. Isotope evidence for N2-fixation in Sphagnum peat bogs

    NASA Astrophysics Data System (ADS)

    Novak, Martin; Jackova, Ivana; Buzek, Frantisek; Stepanova, Marketa; Veselovsky, Frantisek; Curik, Jan; Prechova, Eva

    2016-04-01

    Waterlogged organic soils store as much as 30 % of the world's soil carbon (C), and 15 % of the world's soil nitrogen (N). In the era of climate change, wetlands are vulnerable to increasing temperatures and prolonged periods of low rainfall. Higher rates of microbial processes and/or changing availability of oxygen may lead to peat thinning and elevated emissions of greenhouse gases (mostly CO2, but also CH4 and N2O). Biogeochemical cycling of C and N in peat bogs is coupled. Under low levels of pollution by reactive nitrogen (NO3-, NH4+), increasing N inputs may positively affect C storage in peat. Recent studies in North America and Scandinavia have suggested that pristine bogs are characterized by significant rates of microbial N2 fixation that augments C storage in the peat substrate. We present a nitrogen isotope study aimed at corroborating these findings. We conducted an isotope inventory of N fluxes and pools at two Sphagnum-dominated ombrotrophic peat bogs in the Czech Republic (Central Europe). For the first time, we present a time-series of del15N values of atmospheric input at the same locations as del15N values of living Sphagnum and peat. The mean del15N values systematically increased in the order: input NH4+ (-10.0 ‰) < input NO3- (-7.9 ‰) < peat porewater (-5.6 ‰) < Sphagnum (-5.0 ‰) < shallow peat (-4.2 ‰) < deep peat (-2.2 ‰) < runoff (-1.4 ‰) < porewater N2O (1.4 ‰). Importantly, N of Sphagnum was isotopically heavier than N of the atmospheric input (p < 0.001). If partial incorporation of reactive N from the atmosphere into Sphagnum was isotopically selective, the residual N would have to be isotopically extremely light. Such N, however, was not identified anywhere in the ecosystem. Alternatively, Sphagnum may have contained an admixture of isotopically heavier N from atmospheric N2 (del15N N2 = 0 ‰). We conlude that the N isotope systematics at the two Czech sites is consistent with the concept of significant N2 fixation

  10. [Testate amoebae inhabiting middle taiga bogs in Western Siberia].

    PubMed

    Kur'ina, I V; Preĭs, Iu I; Bobrov, A A

    2010-01-01

    The population of testate amoebae from the most typical middle taiga bogs of Western Siberia have been studied. More than one hundred (103) species and intraspecific taxons of testate amoebae have been revealed in recent surface samples. The relation between ecological characteristics of habitats and the composition of a Protozoa population has been demonstrated. The ecological preferences of species concerning the index of wetness, ash level, and acidity have been revealed. Using the correspondence analysis, the ecological optimums and the tolerance of species and intraspecific taxons of testate amoebae have been established.

  11. Comparisons of soil nitrogen mass balances for an ombrotrophic bog and a minerotrophic fen in northern Minnesota

    EPA Science Inventory

    We compared the N budgets of an ombrotrophic bog and a minerotrophic fen to quantify the importance of denitrification in peatlands and their watersheds. We also compared the watershed upland mineral soils to bog/fen peat; lagg and transition zone peat to central bog/fen peat; an...

  12. Lead isotope ratios in bone ash of blesbok (Damaliscus pygargus phillipsi): a means of screening for the accumulation of contaminants from uraniferous rocks.

    PubMed

    Nöthling, Johan O; Du Toit, Johannes S; Myburgh, Jan G

    2014-09-19

    This study was done to determine whether blesbok (Damaliscus pygargus phillipsi) from the Krugersdorp Game Reserve (KGR) in Gauteng Province, South Africa have higher concentrations of (238)U and higher (206)Pb/(204)Pb and (207)Pb/(204)Pb ratios in their bone ash than blesbok from a nearby control reserve that is not exposed to mine water and has no outcrops of uraniferous rocks. Eight blesbok females from the KGR and seven from the control site, all killed with a brain shot, were used. A Thermo X-series 2 quadrupole ICPMS was used to measure the concentrations of (238)U and lead and a Nu Instruments NuPlasma HR MC-ICP-MS to measure the lead isotope ratios in the tibial ash from each animal. KGR blesbok had higher mean concentrations of (238)U (P = 0.02) and ratios of (206)Pb/(204)Pb and (207)Pb/(204)Pb (P < 0.00001) than the control blesbok. The probability of rejecting the false null hypothesis of no difference in the (206)Pb/(204)Pb or (207)Pb/(204)Pb ratios between KGR and control reserve animals (the power of the test) was 0.999. The blesbok from the KGR accumulated contaminants from an uraniferous environment. The (206)Pb/(204)Pb and (207)Pb/(204)Pb ratios in tibial ash proved effective in confirming accumulation of contaminants from uraniferous rocks.

  13. Electrocoagulation treatment of peat bog drainage water containing humic substances.

    PubMed

    Kuokkanen, V; Kuokkanen, T; Rämö, J; Lassi, U

    2015-08-01

    Electrocoagulation (EC) treatment of 100 mg/L synthetic wastewater (SWW) containing humic acids was optimized (achieving 90% CODMn and 80% DOC removal efficiencies), after which real peat bog drainage waters (PBDWs) from three northern Finnish peat bogs were also treated. High pollutant removal efficiencies were achieved: Ptot, TS, and color could be removed completely, while Ntot, CODMn, and DOC/TOC removal efficiencies were in the range of 33-41%, 75-90%, and 62-75%, respectively. Al and Fe performed similarly as the anode material. Large scale experiments (1 m(3)) using cold (T = 10-11 °C) PBDWs were also conducted successfully, with optimal treatment times of 60-120 min (applying current densities of 60-75 A/m(2)). Residual values of Al and Fe (complete removal) were lower than their initial values in the EC-treated PBDWs. Electricity consumption and operational costs in optimum conditions were found to be low and similar for all the waters studied: 0.94 kWh/m(3) and 0.15 €/m(3) for SWW and 0.35-0.70 kWh/m(3) and 0.06-0.12 €/m(3) for the PBDWs (large-scale). Thus, e.g. solar cells could be considered as a power source for this EC application. In conclusion, EC treatment of PBDW containing humic substances was shown to be feasible.

  14. Fate of silicate minerals in a peat bog

    NASA Astrophysics Data System (ADS)

    Bennett, Philip C.; Siegel, Donald I.; Hill, Barbara M.; Glaser, Paul H.

    1991-04-01

    An investigation of silicate weathering in a Minnesota mire indicates that quartz and aluminosilicates rapidly dissolve in anoxic, organic-rich, neutral- pH environments. Vertical profiles of pH, dissolved silicon, and major cations were obtained at a raised bog and a spring fen and compared. Profiles of readily extractable silicon, diatom abundance, ash mineralogy, and silicate surface texture were determined from peat cores collected at each site. In the bog, normally a recharge mound, dissolved silicon increases with depth as pH increases, exceeding the background silicon concentration by a factor of two. Silicate grain surfaces, including quartz, are chemically etched at this location, despite being in contact with pore water at neutral pH with dissolved silicon well above the equilibrium solubility of quartz. The increasing silica concentrations at circum-neutral pH are consistent with a system where silicate solubility is influenced by silica-organic-acid complexes. Silica-organic-acid complexes therefore may be the cause of the almost complete absence of diatoms in decomposed peat and contribute to the formation of silica-depleted underclays commonly found beneath coal.

  15. Electrocoagulation treatment of peat bog drainage water containing humic substances.

    PubMed

    Kuokkanen, V; Kuokkanen, T; Rämö, J; Lassi, U

    2015-08-01

    Electrocoagulation (EC) treatment of 100 mg/L synthetic wastewater (SWW) containing humic acids was optimized (achieving 90% CODMn and 80% DOC removal efficiencies), after which real peat bog drainage waters (PBDWs) from three northern Finnish peat bogs were also treated. High pollutant removal efficiencies were achieved: Ptot, TS, and color could be removed completely, while Ntot, CODMn, and DOC/TOC removal efficiencies were in the range of 33-41%, 75-90%, and 62-75%, respectively. Al and Fe performed similarly as the anode material. Large scale experiments (1 m(3)) using cold (T = 10-11 °C) PBDWs were also conducted successfully, with optimal treatment times of 60-120 min (applying current densities of 60-75 A/m(2)). Residual values of Al and Fe (complete removal) were lower than their initial values in the EC-treated PBDWs. Electricity consumption and operational costs in optimum conditions were found to be low and similar for all the waters studied: 0.94 kWh/m(3) and 0.15 €/m(3) for SWW and 0.35-0.70 kWh/m(3) and 0.06-0.12 €/m(3) for the PBDWs (large-scale). Thus, e.g. solar cells could be considered as a power source for this EC application. In conclusion, EC treatment of PBDW containing humic substances was shown to be feasible. PMID:25973580

  16. No limits to peat bog growth? Transport and thermodynamic constraints on anaerobic organic matter decomposition

    NASA Astrophysics Data System (ADS)

    Blodau, C.; Julia, B.; Siems, M.

    2009-05-01

    In diffusion dominated systems, for which many thick peat deposits provide a model, slowness of transport and lack of free energy may pose a limit to methanogenic decomposition of organic matter and ultimately to closing the carbon cycle. To test this hypothesis we (I) conducted controlled column experiments with homogenized peat over an 18 month period, (II) investigated transport, in situ respiration pathways, rates and thermodynamic conditions in a nothern peatland, and (III) modelled depth profiles of CO2 and CH4 in the deposits. Vertical transport in the peatland was dominated by diffusion leading to the buildup of DIC and CH4 with depth (5500 µmol L 1 DIC, 500 µmol L 1 CH4). Highest DIC and CH4 production rates occurred close to the water table (decomposition constant kd ~10-3 to 10 4 a-1) and decreased to about kd = 10-7 a-1. The accumulation of metabolic end-products diminished in situ energy yields of acetoclastic methanogenesis to the threshold for microbially mediated processes (-20 to -25 kJ mol-1 CH4). The methanogenic precursor acetate also accumulated (150 µmol L 1). In line with these findings, CH4 was formed by hydrogenotrophic methanogenesis at Gibbs free energies of 35 to 40 kJ mol-1 CH4. This was indicated by an isotopic fractionation αCO2-CH4 of 1.069 to 1.079. Fermentative degradation of acetate, propionate and butyrate attained Gibbs free energies close to 0 kJ mol-1 substrate. In peat columns with homogenenous peat-sand mixtures of 50%, 15% and 5% dry weight, steady state CO2 production also decreased from about 10 to 0 nmol cm-3 d-1 and of CH4 from 1 to 0 nmol cm-3 d-1 with depth. Very similar depth profiles of concentrations and volumetric rates developed near endproduct thresholds of 600µmol CH4 and 10 mmol L-1 CO2, despite the differences in organic matter content. The modeling exercise showed that a consistent development of CH4 concentration profiles over time in the columns could only be accomplished with rates of acetoclastic

  17. Nutrient Addition Leads to a Weaker CO2 Sink and Higher CH4 Emissions through Vegetation-Microclimate Feedbacks at Mer Bleue Bog, Canada

    NASA Astrophysics Data System (ADS)

    Bubier, J. L.; Arnkil, S.; Humphreys, E.; Juutinen, S.; Larmola, T.; Moore, T. R.

    2015-12-01

    Atmospheric nitrogen (N) deposition has led to nutrient enrichment in wetlands globally, affecting plant community composition, carbon (C) cycling, and microbial dynamics. Nutrient-limited boreal bogs are long-term sinks of carbon dioxide (CO2), but sources of methane (CH4), an important greenhouse gas. We fertilized Mer Bleue Bog, a Sphagnum moss and evergreen shrub-dominated ombrotrophic bog near Ottawa, Ontario, for 10-15 years with N as NO3 and NH4 at 5, 10 and 20 times ambient N deposition (0.6-0.8 g N m-2 y-1), with and without phosphorus (P) and potassium (K). Treatments were applied to triplicate plots (3 x 3 m) from May - August 2000-2015 and control plots received distilled water. We measured net ecosystem CO2 exchange (NEE), ecosystem photosynthesis and respiration, and CH4 flux with climate-controlled chambers; leaf-level CO2 exchange and biochemistry; substrate-induced respiration, CH4 production and consumption potentials with laboratory incubations; plant species composition and abundance; and microclimate (peat temperature, moisture, light interception). After 15 years, we have found that NEE has decreased, and CH4 emissions have increased, in the highest nutrient treatments owing to changes in vegetation, microtopography, and peat characteristics. Vegetation changes include a loss of Sphagnum moss and introduction of new deciduous species. Simulated atmospheric N deposition has not benefitted the photosynthetic apparatus of the dominant evergreen shrubs, but resulted in higher foliar respiration, contributing to a weaker ecosystem CO2 sink. Loss of moss has led to wetter near-surface substrate, higher rates of decomposition and CH4 emission, and a shift in microbial communities. Thus, elevated atmospheric deposition of nutrients may endanger C storage in peatlands through a complex suite of feedbacks and interactions among vegetation, microclimate, and microbial communities.

  18. Species identification of archaeological skin objects from Danish bogs: comparison between mass spectrometry-based peptide sequencing and microscopy-based methods.

    PubMed

    Brandt, Luise Ørsted; Schmidt, Anne Lisbeth; Mannering, Ulla; Sarret, Mathilde; Kelstrup, Christian D; Olsen, Jesper V; Cappellini, Enrico

    2014-01-01

    Denmark has an extraordinarily large and well-preserved collection of archaeological skin garments found in peat bogs, dated to approximately 920 BC - AD 775. These objects provide not only the possibility to study prehistoric skin costume and technologies, but also to investigate the animal species used for the production of skin garments. Until recently, species identification of archaeological skin was primarily performed by light and scanning electron microscopy or the analysis of ancient DNA. However, the efficacy of these methods can be limited due to the harsh, mostly acidic environment of peat bogs leading to morphological and molecular degradation within the samples. We compared species assignment results of twelve archaeological skin samples from Danish bogs using Mass Spectrometry (MS)-based peptide sequencing, against results obtained using light and scanning electron microscopy. While it was difficult to obtain reliable results using microscopy, MS enabled the identification of several species-diagnostic peptides, mostly from collagen and keratins, allowing confident species discrimination even among taxonomically close organisms, such as sheep and goat. Unlike previous MS-based methods, mostly relying on peptide fingerprinting, the shotgun sequencing approach we describe aims to identify the complete extracted ancient proteome, without preselected specific targets. As an example, we report the identification, in one of the samples, of two peptides uniquely assigned to bovine foetal haemoglobin, indicating the production of skin from a calf slaughtered within the first months of its life. We conclude that MS-based peptide sequencing is a reliable method for species identification of samples from bogs. The mass spectrometry proteomics data were deposited in the ProteomeXchange Consortium with the dataset identifier PXD001029.

  19. Species Identification of Archaeological Skin Objects from Danish Bogs: Comparison between Mass Spectrometry-Based Peptide Sequencing and Microscopy-Based Methods

    PubMed Central

    Brandt, Luise Ørsted; Schmidt, Anne Lisbeth; Mannering, Ulla; Sarret, Mathilde; Kelstrup, Christian D.; Olsen, Jesper V.; Cappellini, Enrico

    2014-01-01

    Denmark has an extraordinarily large and well-preserved collection of archaeological skin garments found in peat bogs, dated to approximately 920 BC – AD 775. These objects provide not only the possibility to study prehistoric skin costume and technologies, but also to investigate the animal species used for the production of skin garments. Until recently, species identification of archaeological skin was primarily performed by light and scanning electron microscopy or the analysis of ancient DNA. However, the efficacy of these methods can be limited due to the harsh, mostly acidic environment of peat bogs leading to morphological and molecular degradation within the samples. We compared species assignment results of twelve archaeological skin samples from Danish bogs using Mass Spectrometry (MS)-based peptide sequencing, against results obtained using light and scanning electron microscopy. While it was difficult to obtain reliable results using microscopy, MS enabled the identification of several species-diagnostic peptides, mostly from collagen and keratins, allowing confident species discrimination even among taxonomically close organisms, such as sheep and goat. Unlike previous MS-based methods, mostly relying on peptide fingerprinting, the shotgun sequencing approach we describe aims to identify the complete extracted ancient proteome, without preselected specific targets. As an example, we report the identification, in one of the samples, of two peptides uniquely assigned to bovine foetal haemoglobin, indicating the production of skin from a calf slaughtered within the first months of its life. We conclude that MS-based peptide sequencing is a reliable method for species identification of samples from bogs. The mass spectrometry proteomics data were deposited in the ProteomeXchange Consortium with the dataset identifier PXD001029. PMID:25260035

  20. Isotopic Composition of Pb in Peat and Porewaters from Three Contrasting Ombrotrophic Bogs in Finland: Evidence of Chemical Diagenesis in Response to Acidification.

    PubMed

    Shotyk, William; Rausch, Nicole; Nieminen, Tiina M; Ukonmaanaho, Liisa; Krachler, Michael

    2016-09-20

    The isotopic composition of Pb was determined in Finnish peat bogs and their porewaters from Harjavalta (HAR, near a Cu-Ni smelter), Outokumpu (OUT, near a Cu-Ni mine), and Hietajärvi (HIJ, a background site). At HIJ and OUT, the porewaters yielded similar concentrations (0.1-0.7 μg/L) and isotopic composition ((206)Pb/(207)Pb = 1.154-1.164). In contrast, the peat profile from HAR yielded greater concentrations of Pb in the porewaters (average 2.4 μg/L), and the Pb is less radiogenic ((206)Pb/(207)Pb = 1.121-1.149). Acidification of the bog surface waters to pH 3.5 by SO2 emitted from smelting (compared to pH 4.0 at the control site) apparently promotes the dissolution of Pb-bearing aerosols, as well as desorption of metals from the surfaces of these particles and from the peat matrix. Despite this, the chronology of anthropogenic, atmospheric deposition for the past millenium recorded by the isotopic composition of Pb in all three peat bogs is remarkably similar. While the immobility of Pb in the peat cores may appear inconsistent with the elevated porewater Pb concentrations, Pb concentrations in the aqueous phase never amount to more than 0.01% of the total Pb at any given depth so that the potential for migration remains small. The low rates of vertical water movement in bogs generally combined with the size of the metal-containing particles in solution may be additional factors limiting Pb mobilization. PMID:27536961

  1. Isotopic Composition of Pb in Peat and Porewaters from Three Contrasting Ombrotrophic Bogs in Finland: Evidence of Chemical Diagenesis in Response to Acidification.

    PubMed

    Shotyk, William; Rausch, Nicole; Nieminen, Tiina M; Ukonmaanaho, Liisa; Krachler, Michael

    2016-09-20

    The isotopic composition of Pb was determined in Finnish peat bogs and their porewaters from Harjavalta (HAR, near a Cu-Ni smelter), Outokumpu (OUT, near a Cu-Ni mine), and Hietajärvi (HIJ, a background site). At HIJ and OUT, the porewaters yielded similar concentrations (0.1-0.7 μg/L) and isotopic composition ((206)Pb/(207)Pb = 1.154-1.164). In contrast, the peat profile from HAR yielded greater concentrations of Pb in the porewaters (average 2.4 μg/L), and the Pb is less radiogenic ((206)Pb/(207)Pb = 1.121-1.149). Acidification of the bog surface waters to pH 3.5 by SO2 emitted from smelting (compared to pH 4.0 at the control site) apparently promotes the dissolution of Pb-bearing aerosols, as well as desorption of metals from the surfaces of these particles and from the peat matrix. Despite this, the chronology of anthropogenic, atmospheric deposition for the past millenium recorded by the isotopic composition of Pb in all three peat bogs is remarkably similar. While the immobility of Pb in the peat cores may appear inconsistent with the elevated porewater Pb concentrations, Pb concentrations in the aqueous phase never amount to more than 0.01% of the total Pb at any given depth so that the potential for migration remains small. The low rates of vertical water movement in bogs generally combined with the size of the metal-containing particles in solution may be additional factors limiting Pb mobilization.

  2. Microform-related community patterns of methane-cycling microbes in boreal Sphagnum bogs are site specific.

    PubMed

    Juottonen, Heli; Kotiaho, Mirkka; Robinson, Devin; Merilä, Päivi; Fritze, Hannu; Tuittila, Eeva-Stiina

    2015-09-01

    Vegetation and water table are important regulators of methane emission in peatlands. Microform variation encompasses these factors in small-scale topographic gradients of dry hummocks, intermediate lawns and wet hollows. We examined methane production and oxidization among microforms in four boreal bogs that showed more variation of vegetation within a bog with microform than between the bogs. Potential methane production was low and differed among bogs but not consistently with microform. Methane oxidation followed water table position with microform, showing higher rates closer to surface in lawns and hollows than in hummocks. Methanogen community, analysed by mcrA terminal restriction fragment length polymorphism and dominated by Methanoregulaceae or 'Methanoflorentaceae', varied strongly with bog. The extent of microform-related variation of methanogens depended on the bog. Methanotrophs identified as Methylocystis spp. in pmoA denaturing gradient gel electrophoresis similarly showed effect of bog, and microform patterns were stronger within individual bogs. Our results suggest that methane-cycling microbes in boreal Sphagnum bogs with seemingly uniform environmental conditions may show strong site-dependent variation. The bog-intrinsic factor may be related to carbon availability but contrary to expectations appears to be unrelated to current surface vegetation, calling attention to the origin of carbon substrates for microbes in bogs.

  3. Microbial communities and greenhouse gas production from a thermokarst bog chronosequence: Mechanisms of rapid carbon loss

    NASA Astrophysics Data System (ADS)

    Waldrop, M. P.; Jones, M.; Manies, K.; Mcfarland, J. W.; Blazewicz, S.; Keller, J.; Haw, M.; Harden, J. W.; Medvedeff, C.; Turetsky, M. R.

    2015-12-01

    Climate change in northern latitudes is expected to cause widespread permafrost thaw in Interior Alaska over the 21st century. Permafrost thaw may result in land subsidence and the formation of thermokarst bogs. In decades following thaw, previously forest floor (silvic) carbon (C) may be rapidly decomposed, likely due to accelerated microbial activities in young bog environments, resulting in a decadal to century scale positive feedback to climate warming. We examined rates and mechanisms of C loss from a thermokarst bog chronosequence (0-500 ybp) at the Alaska Peatland Experiment (APEX), part of the Bonanza Creek LTER near Fairbanks, AK. Silvic C losses were within ranges observed at other thermokarst chronosequence studies. Incubation studies and modeling results indicate that there are accelerated rates of microbial activity within the deeper silvic and humic soil horizons of the youngest bog. We hypothesized two potential mechanisms of rapid C loss and higher microbial activity in young thermokarst bogs: 1) higher availability of electron acceptors from thawed permafrost that fuel microbial activity, and 2) increased availability of labile C from both soil organic matter and dissolved organic matter in young bogs fuel microbial activity. We tested these hypotheses using anaerobic soil incubations and assays of sulfate reduction, Fe reduction, humic substance (HS) reduction, and nitrate reduction, combined with quantitative PCR of microbial functional groups associated with those processes. Assay results indicated that although sulfate reduction and denitrification were detectable in several of the bogs, only HS reduction was unique to the deep layers of the young thermokarst bog. The most striking difference among different aged bogs was dissolved organic matter, which was elevated in the youngest bogs. These results support both of our hypotheses: microbial activity is stimulated by the availability of labile C in the young bog as both a source of C for

  4. The aqueous geochemistry of uranium in a drainage containing uraniferous organic-rich sediments, Lake Tahoe area, Nevada, USA

    USGS Publications Warehouse

    Zielinski, R.A.; Otton, J.K.; Wanty, R.B.; Pierson, C.T.

    1988-01-01

    Anomalously uraniferous waters occur in a small (4.2 km2) drainage in the west-central Carson Range, Nevada, on the eastern side of Lake Tahoe. The waters transport uranium from local U-rich soils and bedrock to organic-rich valley-fill sediments where it is concentrated, but weakly bound. The dissolved U and the U that is potentially available from coexisting sediments pose a threat to the quality of drinking water that is taken from the drainage. The U concentration in samples of 6 stream, 11 spring and 7 near-surface waters ranged from 0.1 V). Possible precipitation of U(IV) minerals is predicted under the more reducing conditions that are particularly likely in near-surface waters, but the inhibitory effects of sluggish kinetics or organic complexing are not considered. These combined results suggest that a process such as adsorption or ion exchange, rather than mineral saturation, is the most probable mechanism for uranium fixation in the sediments. -Authors

  5. Environmental assessment of remedial action at the inactive uraniferous lignite ashing sites at Belfield and Bowman, North Dakota

    SciTech Connect

    Not Available

    1993-09-01

    The Uranium Mill Tailings Radiation Control Act (UMTRCA) of 1978 authorized the US Department of Energy (DOE) to perform remedial actions at Belfield and Bowman inactive lignite ashing sites in southwestern North Dakota to reduce the potential public health impacts from the residual radioactivity remaining at the sites. The US Environmental Protection Agency (EPA) promulgated standards (40 CFR 192) that contain measures to control the residual radioactive materials and other contaminated materials, and proposed standards to protect the groundwater from further degradation. Remedial action at the Belfield and Bowman sites must be performed in accordance with these standards and with the concurrence of the US Nuclear Regulatory Commission (NRC) and the state of North Dakota. The Belfield and Bowman designated sites were used by Union Carbide and Kerr-McGee, respectively, to process uraniferous lignite in the 1960s. Uranium-rich ash from rotary kiln processing of the lignite was loaded into rail cars and transported to uranium mills in Rifle, Colorado, and Ambrosia Lake, New Mexico, respectively. As a result of the ashing process, there is a total of 158,400 cubic yards (yd{sup 3}) [121,100 cubic meters (m{sup 3})] of radioactive ash-contaminated soils at the two sites. Windblown ash-contaminated soil covers an additional 21 acres (8.5 ha) around the site, which includes grazing land, wetlands, and a wooded habitat.

  6. Environmental assessment of no remedial action at the inactive uraniferous lignite ashing sites at Belfield and Bowman, North Dakota

    SciTech Connect

    1997-06-01

    The Belfield and Bowman sites were not included on the original congressional list of processing sites to be designated by the Secretary of Energy. Instead, the sites were nominated for designation by the Dakota Resource Council in a letter to the DOE (September 7, 1979). In a letter to the DOE (September 12, 1979), the state of North Dakota said that it did not believe the sites would qualify as processing sites under the Uranium Mill Tailings Radiation Control Act (UMTRCA) because the activities at the sites involved only the ashing of uraniferous lignite coal and the ash was shipped out of state for actual processing. Nevertheless, on October 11, 1979, the state of North Dakota agreed to the designation of the sites because they met the spirit of the law (reduce public exposure to radiation resulting from past uranium operations). Therefore, these sites were designated by the Secretary of Energy for remedial action. Because of the relatively low health impacts determined for these sites, they were ranked as low priority and scheduled to be included in the final group of sites to be remediated.

  7. Fate and Transport of Road Salt During Snowmelt Through a Calcareous Fen: Kampoosa Bog, Stockbridge, Massachusetts

    NASA Astrophysics Data System (ADS)

    Rhodes, A. L.; Guswa, A. J.; Pufall, A.

    2007-12-01

    Kampoosa Bog is the largest and most ecologically diverse calcareous lake-basin fen in Massachusetts. Situated within a 4.7 km2 drainage basin, the open fen (approx. 20 acres) consists of a floating mat of sedges (incl. Carex aquatilis and Cladium mariscoides) that overlie peat and lake clay deposits. Mineral weathering of marble bedrock within the drainage basin supplies highly alkaline ground and surface waters to the fen basin. The natural chemistry has been greatly altered by road salt runoff from the Massaschusetts Turnpike, and in question is whether disturbance from the Turnpike and a gas pipline has facilitated aggressive growth by the invasive species Phragmites australis. Considered to be one of the most significant rare species habitats in the state, Massachusetts has designated Kampoosa Bog an Area of Critical Environmental Concern, and a committee representing several local, regional, and state agencies, organizations, and citizens manages the wetland. The purpose of this study is to characterize the hydrologic and chemical response of the wetland during snowmelt events to understand the fate and movement of road salt (NaCl). Concentrations of Na and Cl in the fen groundwater are greatest close to the Turnpike. Concentrations decrease with distance downstream but are still greatly elevated relative to sites upstream of the Turnpike. During snowmelt events, the fen's outlet shows a sharp rise in Na and Cl concentrations at the onset of melting that is soon diluted by the added meltwater. The Na and Cl flux, however, is greatest at peak discharge, suggesting that high-flow events are significant periods of export of dissolved salts from the fen. Pure dissolution of rock salt produces an equal molar ratio between Na and Cl, and sodium and chloride imbalances in stream and ground waters suggest that ~20% of the Na is stored on cation exchange sites within the peat. The largest imbalances between Na and Cl occur deeper within the peat, where the peat is

  8. Reconnaissance for uraniferous rocks in northwestern Colorado, southwestern Wyoming, and northeastern Utah

    USGS Publications Warehouse

    Beroni, E.P.; McKeown, F.A.

    1952-01-01

    Previous discoveries and studies of radioactive lignites of Tertiary age in North Dakota, South Dakota, Montana, and Wyoming led the Geological Survey in 1950 to do reconnaissance in the Green River and Uinta Basin of Wyoming and Utah, where similar lignites were believed to be present. Because of the common association of uranium with copper deposits and the presence of such deposits in the Uinta Basin, several areas containing copper-uranium minerals were also examined. No deposits commercially exploitable under present conditions were found. Samples of coal from the Bear River formation at Sage, Wyo., assayed 0.004 to 0.013 percent uranium in the ash; in the old Uteland copper mine in Uinta County, Utah, 0.007 to 0.017 percent uranium; in a freshwater limestone, Duchesne County, Utah, as much as 0.019 percent uranium; and in the Mesaverde formation at the Snow and Bonniebell claims near Jensen, Uintah County, Utah, 0.003 to 0.090 percent uranium. Maps were made and samples were taken at the Skull Creek carnotite deposits in Moffat County, Colo. (0.006 to 0.16 percent uranium); at the Fair-U claims in Routt County, Colo. (0.002 to 0.040 percent uranium); and at the Lucky Strike claims near Kremmling in Grand County, Colo. (0.006 to 0.018 percent uranium).

  9. Geology and recognition criteria for uranium deposits of the quartz-pebble conglomerate type. Final report

    SciTech Connect

    Button, A.; Adams, S.S.

    1981-03-01

    This report is concerned with Precambrian uraniferous conglomerates. This class of deposit has been estimated to contain between approximately 16 and 35 percent of the global uranium reserve in two rather small areas, one in Canada, the other in South Africa. Similar conglomerates, which are often gold-bearing, are, however, rather widespread, being found in parts of most Precambrian shield areas. Data have been synthesized on the geologic habitat and character of this deposit type. The primary objective has been to provide the most relevant geologic observations in a structural fashion to allow resource studies and exploration to focus on the most prospective targets in the shortest possible time.

  10. Climate-driven expansion of blanket bogs in Britain during the Holocene

    NASA Astrophysics Data System (ADS)

    Gallego-Sala, A. V.; Charman, D. J.; Harrison, S. P.; Li, G.; Prentice, I. C.

    2016-01-01

    Blanket bog occupies approximately 6 % of the area of the UK today. The Holocene expansion of this hyperoceanic biome has previously been explained as a consequence of Neolithic forest clearance. However, the present distribution of blanket bog in Great Britain can be predicted accurately with a simple model (PeatStash) based on summer temperature and moisture index thresholds, and the same model correctly predicts the highly disjunct distribution of blanket bog worldwide. This finding suggests that climate, rather than land-use history, controls blanket-bog distribution in the UK and everywhere else. We set out to test this hypothesis for blanket bogs in the UK using bioclimate envelope modelling compared with a database of peat initiation age estimates. We used both pollen-based reconstructions and climate model simulations of climate changes between the mid-Holocene (6000 yr BP, 6 ka) and modern climate to drive PeatStash and predict areas of blanket bog. We compiled data on the timing of blanket-bog initiation, based on 228 age determinations at sites where peat directly overlies mineral soil. The model predicts that large areas of northern Britain would have had blanket bog by 6000 yr BP, and the area suitable for peat growth extended to the south after this time. A similar pattern is shown by the basal peat ages and new blanket bog appeared over a larger area during the late Holocene, the greatest expansion being in Ireland, Wales, and southwest England, as the model predicts. The expansion was driven by a summer cooling of about 2 °C, shown by both pollen-based reconstructions and climate models. The data show early Holocene (pre-Neolithic) blanket-bog initiation at over half of the sites in the core areas of Scotland and northern England. The temporal patterns and concurrence of the bioclimate model predictions and initiation data suggest that climate change provides a parsimonious explanation for the early Holocene distribution and later expansion of

  11. Climate-driven expansion of blanket bogs in Britain during the Holocene

    NASA Astrophysics Data System (ADS)

    Gallego-Sala, A. V.; Charman, D. J.; Harrison, S. P.; Li, G.; Prentice, I. C.

    2015-10-01

    Blanket bog occupies approximately 6 % of the area of the UK today. The Holocene expansion of this hyperoceanic biome has previously been explained as a consequence of Neolithic forest clearance. However, the present distribution of blanket bog in Great Britain can be predicted accurately with a simple model (PeatStash) based on summer temperature and moisture index thresholds, and the same model correctly predicts the highly disjunct distribution of blanket bog worldwide. This finding suggests that climate, rather than land-use history, controls blanket-bog distribution in the UK and everywhere else. We set out to test this hypothesis for blanket bogs in the UK using bioclimate envelope modelling compared with a database of peat initiation age estimates. We used both pollen-based reconstructions and climate model simulations of climate changes between the mid-Holocene (6000 yr BP, 6 ka) and modern climate to drive PeatStash and predict areas of blanket bog. We compiled data on the timing of blanket-bog initiation, based on 228 age determinations at sites where peat directly overlies mineral soil. The model predicts large areas of northern Britain would have had blanket bog by 6000 yr BP, and the area suitable for peat growth extended to the south after this time. A similar pattern is shown by the basal peat ages and new blanket bog appeared over a larger area during the late Holocene, the greatest expansion being in Ireland, Wales and southwest England, as the model predicts. The expansion was driven by a summer cooling of about 2 °C, shown by both pollen-based reconstructions and climate models. The data show early Holocene (pre-Neolithic) blanket-bog initiation at over half of the sites in the core areas of Scotland, and northern England. The temporal patterns and concurrence of the bioclimate model predictions and initiation data suggest that climate change provides a parsimonious explanation for the early Holocene distribution and later expansion of blanket

  12. Persistent versus transient tree encroachment of temperate peat bogs: effects of climate warming and drought events.

    PubMed

    Heijmans, Monique M P D; van der Knaap, Yasmijn A M; Holmgren, Milena; Limpens, Juul

    2013-07-01

    Peatlands store approximately 30% of global soil carbon, most in moss-dominated bogs. Future climatic changes, such as changes in precipitation patterns and warming, are expected to affect peat bog vegetation composition and thereby its long-term carbon sequestration capacity. Theoretical work suggests that an episode of rapid environmental change is more likely to trigger transitions to alternative ecosystem states than a gradual, but equally large, change in conditions. We used a dynamic vegetation model to explore the impacts of drought events and increased temperature on vegetation composition of temperate peat bogs. We analyzed the consequences of six patterns of summer drought events combined with five temperature scenarios to test whether an open peat bog dominated by moss (Sphagnum) could shift to a tree-dominated state. Unexpectedly, neither a gradual decrease in the amount of summer precipitation nor the occurrence of a number of extremely dry summers in a row could shift the moss-dominated peat bog permanently into a tree-dominated peat bog. The increase in tree biomass during drought events was unable to trigger positive feedbacks that keep the ecosystem in a tree-dominated state after a return to previous 'normal' rainfall conditions. In contrast, temperature increases from 1 °C onward already shifted peat bogs into tree-dominated ecosystems. In our simulations, drought events facilitated tree establishment, but temperature determined how much tree biomass could develop. Our results suggest that under current climatic conditions, peat bog vegetation is rather resilient to drought events, but very sensitive to temperature increases, indicating that future warming is likely to trigger persistent vegetation shifts.

  13. Functional diversity, succession, and human-mediated disturbances in raised bog vegetation.

    PubMed

    Dyderski, Marcin K; Czapiewska, Natalia; Zajdler, Mateusz; Tyborski, Jarosław; Jagodziński, Andrzej M

    2016-08-15

    Raised and transitional bogs are one of the most threatened types of ecosystem, due to high specialisation of biota, associated with adaptations to severe environmental conditions. The aim of the study was to characterize the relationships between functional diversity (reflecting ecosystem-shaping processes) of raised bog plant communities and successional gradients (expressed as tree dimensions) and to show how impacts of former clear cuts may alter these relationships in two raised bogs in 'Bory Tucholskie' National Park (N Poland). Herbaceous layers of the plant communities were examined by floristic relevés (25m(2)) on systematically established transects. We also assessed patterns of tree ring widths. There were no relationships between vegetation functional diversity components and successional progress: only functional dispersion was negatively, but weakly, correlated with median DBH. Lack of these relationships may be connected with lack of prevalence of habitat filtering and low level of competition over all the successional phases. Former clear cuts, indicated by peaks of tree ring width, influenced the growth of trees in the bogs studied. In the bog with more intensive clear cuts we found more species with higher trophic requirements, which may indicate nutrient influx. However, we did not observe differences in vegetation patterns, functional traits or functional diversity indices between the two bogs studied. We also did not find an influence of clear cut intensity on relationships between functional diversity indices and successional progress. Thus, we found that alteration of the ecosystems studied by neighbourhood clear cuts did not affect the bogs strongly, as the vegetation was resilient to these impacts. Knowledge of vegetation resilience after clear cuts may be crucial for conservation planning in raised bog ecosystems.

  14. Functional diversity, succession, and human-mediated disturbances in raised bog vegetation.

    PubMed

    Dyderski, Marcin K; Czapiewska, Natalia; Zajdler, Mateusz; Tyborski, Jarosław; Jagodziński, Andrzej M

    2016-08-15

    Raised and transitional bogs are one of the most threatened types of ecosystem, due to high specialisation of biota, associated with adaptations to severe environmental conditions. The aim of the study was to characterize the relationships between functional diversity (reflecting ecosystem-shaping processes) of raised bog plant communities and successional gradients (expressed as tree dimensions) and to show how impacts of former clear cuts may alter these relationships in two raised bogs in 'Bory Tucholskie' National Park (N Poland). Herbaceous layers of the plant communities were examined by floristic relevés (25m(2)) on systematically established transects. We also assessed patterns of tree ring widths. There were no relationships between vegetation functional diversity components and successional progress: only functional dispersion was negatively, but weakly, correlated with median DBH. Lack of these relationships may be connected with lack of prevalence of habitat filtering and low level of competition over all the successional phases. Former clear cuts, indicated by peaks of tree ring width, influenced the growth of trees in the bogs studied. In the bog with more intensive clear cuts we found more species with higher trophic requirements, which may indicate nutrient influx. However, we did not observe differences in vegetation patterns, functional traits or functional diversity indices between the two bogs studied. We also did not find an influence of clear cut intensity on relationships between functional diversity indices and successional progress. Thus, we found that alteration of the ecosystems studied by neighbourhood clear cuts did not affect the bogs strongly, as the vegetation was resilient to these impacts. Knowledge of vegetation resilience after clear cuts may be crucial for conservation planning in raised bog ecosystems. PMID:27110977

  15. The water balance as an approach to assessing groundwater dependency in raised bog wetlands

    NASA Astrophysics Data System (ADS)

    Regan, Shane

    2014-05-01

    The management of raised bogs, as active peat-forming ecosystems, requires an understanding of the relationships between regional hydrology and wetland ecohydrological processes. Marginal drainage, < 20 years, of Clara Bog, Ireland, has resulted in dramatic morphological changes. Differential peat consolidation has fragmented what was one topographic catchment area into four distinct catchment areas. Runoff has reduced by c. 40% from the original main catchment area and there has been a c. 25% decrease of suitably saturated areas supporting the growth of sphagnum moss species. In undisturbed bog systems the recharge rate of water seeping through the bog body to the regional groundwater table is in the order of 40 mm/ year. The downward seepage rate in Clara is > 100 mm/ year. A reduction in pore water pressure, due to drainage of the regional groundwater table, has disturbed the structure of the peat substratum and induced water loss from peat storage, resulting in the ecohydrological modification of the bog surface. Numerical modelling of a simulated raised groundwater table reduces the leakage rate to between 30 and 50 mm/ year. The significance is that the hydraulic gradient of the regional groundwater table is an important environmental supporting condition in raised bog ecosystems, implying indirect groundwater dependence.

  16. Radioactive deposits of Nevada

    USGS Publications Warehouse

    Lovering, T.G.

    1953-01-01

    Thirty-five occurrences of radioactive rocks had been reported from Nevada prior to 1952. Twenty-five of these had been investigated by the U. S. Geological Survey and the U. S. Atomic Energy Commission. Of those investigated, uranium minerals were identified in 13; two contained a thorium mineral (monazite); the source of radioactivity on 7 properties was not ascertained; and one showed no abnormal radioactivity. Of the other reported occurrences, one is said to contain uraniferous hydrocarbons and 9 are placers containing thorian monazite. Pitchblende occurs at two localities; the East Walker River area, and the Stalin's Present prospect, where it is sparsely disseminated in tabular bodies cutting granitic rocks. Other uranium minerals found in the state include: carnotite, tyuyamunite, autunite, torbernite, gummite, uranophane, kasolite, and an unidentified mineral which may be dumontit. Monazite is the only thorium mineral of possible economic importance that has been reported. From an economic standpoint 9 only 4 of the properties examined showed reserves of uranium ore in 1952; these are: the Green Monster mine, which shipped 5 tons of ore to Marysvale, Utah, during 1951, the Majuba Hill mine, the Stalin's Present prospect, and the West Willys claim in the Washington district. Reserves of ore grade are small on all of these properties and probably cannot be developed commercially unless an ore-buying station is set up nearby. No estimate has been made of thorium reserves and no commercial deposits of thorium are known.

  17. Radioactive deposits of Nevada

    USGS Publications Warehouse

    Lovering, T.G.

    1954-01-01

    Thirty-five occurrences of radioactive rocks had been reported from Nevada prior to 1952. Twenty-five of these had been investigated by personnel of the U. S. Geological Surveyor of the U. S. Atomic Energy Commission. Of those investigated, uranium minerals were identified at 13 sites; two sites contained a thorium mineral (monazite); the source of radioactivity on nine properties was not ascertained, and one showed no abnormal radioactivity. Of the other reported occurrences, one is said to contain uraniferous hydrocarbons and nine are placers containing thorian monazite. Pitchblende occurs at two localities, the East Walker River area, and the Stalin's Present prospect, where it is sparsely disseminated in tabular bodies cutting granitic rocks. Other uranium minerals found in the state include: carnotite, tyuyamunite, autunite, torbernite, gummite, uranophane, kasolite, and an unidentified mineral which may be dumontite. Monazite is the only thorium mineral of possible economic importance that has been reported. From an economic standpoint, only four of the properties examined showed reserves of uranium ore in 1952; these are: the Green Monster mine, which shipped 5 tons of ore to Marysvale, Utah, during 1951; the Majuba Hill mine; the Stalin's Present prospect; and the West Willys claim in the Washington district. No estimate has been made of thorium reserves and no commercial deposits of thorium are known.

  18. Can continental bogs withstand the pressures from climate change?

    NASA Astrophysics Data System (ADS)

    Roulet, Nigel; Humphreys, Elyn; Wu, Jianghua; Frolking, Steve; Talbot, Julie; Lafleur, Peter; Moore, Tim

    2016-04-01

    Not all peatlands are alike. Theoretical and process based models suggest that ombrogenic, oligotrophic peatlands can withstand the pressures due to climate change because of the feedbacks among ecosystem production, decomposition and water storage. Although there have been many inductive explanations inferring from paleo-records, there is a lack of deductive empirical tests of the models predictions of these systems' stability and there are few records of the changes in the net ecosystem carbon balance (NECB) of peatlands that are long enough to examine the dynamics of the NECB in relation to climate variability. Continuous measurements of all the components of the NECB and the associated general climatic and environmental conditions have been made at the Mer Bleue (MB) peatland, a large, 28 km2, 5 m deep, raised ombro-oligotrophic, shrub and Sphagnum covered bog, near Ottawa, Canada from May 1, 1998 until the present. The sixteen-year daily CO2, CH4, and DOC flux and NECB covers a wide range of variability in peatland water storage from very dry to very wet growing seasons. We used the MB data to test the extent of MB peatland's stability and the strength of the underlying key feedback between the NECB and changes in water storage projected by the models. In 2007 we published a six-year (1999-2004) net ecosystem carbon balance (NECB) for MB of ~22 ± 40 g C m-2 yr-1, but we have since recalculated the 1998-2004 NECB to be 32 ± 40 g C m-2 yr-1 based on a reanalyzed average NEP of 51 ± 41 g C m-2 yr-1. Over the same period the net loss of C via the CH4 and DOC fluxes were -4 ± 1 and -15 ± 3 g C m-2 yr-1. The 1998-2004 six-year MB average NECB is similar to the long-term C accumulation rate, estimated from MB peat cores, for the last 3,000 years. The post 2004 MB NEP has increased to an average of ~96 ± 32 g C m-2 yr-1 largely to there being generally wetter growing seasons. The losses of C via DOC (18 ± 1 g C m-2 yr-1) and CH4 (7 ± 4 g C m-2 yr-1) while

  19. Uranium deposits in Grant County, New Mexico

    USGS Publications Warehouse

    Granger, Harry C.; Bauer, Herman L.; Lovering, Tom G.; Gillerman, Elliot

    1952-01-01

    The known uranium deposits of Grant county, N. Mex., are principally in the White Signal and Black Hawk districts. Both districts are within a northwesterly-trending belt of pre-Cambrian rocks, composed chiefly of granite with included gneisses, schists, and quartzites. Younger dikes and stocks intrude the pre-Cambrian complex. The White Signal district is on the southeast flanks of the Burro Mountains; the Black Hawk district is about 18 miles northwest of the town of White Signal. In the White Signal district the seconday uranium phosphates--autunite and torbernite--occur as fracture coatings and disseminations in oxidized parts of quartz-pyrite veins, and in the adjacent mafic dikes and granites; uraniferous limonite is common locally. Most of the known uraniferous deposits are less that 50 feet in their greatest dimension. The most promising deposits in the district are on the Merry Widow and Blue Jay claims. The richest sample taken from the Merry Widow mine contained more than 2 percent uranium and a sample from the Blue Jay property contained as much as 0.11 percent; samples from the other properties were of lower grade. In the Black Hawk district pitchblende is associated with nickel, silver, and cobalt minerals in fissure veins. The most promising properties in the Black Hawk district are the Black Hawk, Alhambra, and Rose mines. No uranium analyses from this district were available in 1951. There are no known minable reserves of uranium ore in either district, although there is some vein material at the Merry Widow mine of ore grade, if a market were available in the region.

  20. The hydrology of natural and artificial bog pools

    NASA Astrophysics Data System (ADS)

    Holden, Joseph; Turner, Ed; McKenzie, Rebecca; Baird, Andy; Billett, Mike; Chapman, Pippa; Dinsmore, Kerry; Dooling, Gemma

    2016-04-01

    Twelve bog pools were monitored over a 3.5-year period (2012-2015) in the Cross Lochs blanket peatland in the Flow Country of northern Scotland. Six pools were located in a natural pool complex while the other six were in an adjacent area where the peat had been ditched in the 1970s. The ditches had been subsequently dammed with peat in 2002 resulting in dozens of artificial pools along each ditch, with one pool upslope of each dam. The natural pools ranged in area from 15 m2 to 850 m2, while the artificial pools are a more uniform size at c.3 - 4 m2. Following a dry first summer, water levels in the 12 pools were lower throughout the subsequent winter and spring than they were in proceeding years showing strong inter-annual variability in pool levels even for winter months. Over the three year study, water level fluctuations in the natural pools were very different to those in the artificial pools. The natural pools showed subdued responses to rainfall and, after rainfall, slow falls in water level dominated by evaporation; the hydraulic conductivity of the peat was very low at depths of 30 and 50 cm below the peat surface around the pools (median values of 2.49 × 10-5 and 1.09 × 10-5 cm s-1 respectively). The artificial pools had much larger monthly interquartile ranges of water levels and a greater rise and fall of pool water level in response to each individual rainfall event compared with the natural pools. Thus the biogeochemistry and carbon cycling processes that occur within the natural pools is not likely to be replicated in the artificial pools as their hydrological behaviour is quite different. Slope position was a factor in terms of hydrological response of pools with those further downslope having higher relative water levels for longer periods of time compared to upslope pools. Thus we anticipate that local biogeochemical processes in and around bog pools may be impacted by slope position and by whether they are natural pools or artificial pools

  1. The growth of permafrost-free bogs at the southern margin of permafrost, 1947-2010

    NASA Astrophysics Data System (ADS)

    Quinton, W. L.; Sonnentag, O.; Connon, R.; Chasmer, L.

    2013-12-01

    In the high-Boreal region of NW Canada, permafrost occurs predominantly in the form of tree-covered peat plateaus within a permafrost-free and treeless terrain dominated by flat bogs. This region is experiencing unprecedented rates of thaw. Over the last several decades, such thaw has significantly expanded the permafrost-free, treeless terrain at the expense of the plateaus. This rapid change in land-cover has raised concerns over its impact on northern water resources, since remotely sensed data and ground observations indicate that the two major land-covers in this region have very different hydrological functions. Peat plateaus have a limited capacity to store water, a relatively large snowmelt water supply and hydraulic gradients that direct excess water into adjacent permafrost-free wetlands. As such, the plateaus function primarily as runoff generators. Plateaus also obstruct and redirect water movement in adjacent wetlands since the open water surfaces of the latter occupy an elevation below the permafrost table. By contrast, bogs are primarily water storage features since they are surrounded by raised permafrost and therefore less able to exchange surface and near-surface flows with the basin drainage network. Accurate estimate of the permafrost and permafrost-free areas is needed for accurate predictions of basin runoff and storage. This study examines the perimeter-area characteristics of bogs and permafrost plateaus, using fractal geometry as a basis for quantifying these properties. Image analyses are applied to aerial photographs and satellite imagery of Scotty Creek, NWT over the period 1947-2010. Preliminary analyses suggest that the expanding bogs and shrinking permafrost plateaus behave as fractals, meaning that their perimeter-area characteristics can be described by simple power equations. The area-frequency characteristics of bogs and plateaus have a hyperbolic distribution with relatively few large bogs and plateaus and numerous small ones

  2. Increased tree establishment in Lithuanian peat bogs--insights from field and remotely sensed approaches.

    PubMed

    Edvardsson, Johannes; Šimanauskienė, Rasa; Taminskas, Julius; Baužienė, Ieva; Stoffel, Markus

    2015-02-01

    Over the past century an ongoing establishment of Scots pine (Pinus sylvestris L.), sometimes at accelerating rates, is noted at three studied Lithuanian peat bogs, namely Kerėplis, Rėkyva and Aukštumala, all representing different degrees of tree coverage and geographic settings. Present establishment rates seem to depend on tree density on the bog surface and are most significant at sparsely covered sites where about three-fourth of the trees have established since the mid-1990s, whereas the initial establishment in general was during the early to mid-19th century. Three methods were used to detect, compare and describe tree establishment: (1) tree counts in small plots, (2) dendrochronological dating of bog pine trees, and (3) interpretation of aerial photographs and historical maps of the study areas. In combination, the different approaches provide complimentary information but also weigh up each other's drawbacks. Tree counts in plots provided a reasonable overview of age class distributions and enabled capturing of the most recently established trees with ages less than 50 years. The dendrochronological analysis yielded accurate tree ages and a good temporal resolution of long-term changes. Tree establishment and spread interpreted from aerial photographs and historical maps provided a good overview of tree spread and total affected area. It also helped to verify the results obtained with the other methods and an upscaling of findings to the entire peat bogs. The ongoing spread of trees in predominantly undisturbed peat bogs is related to warmer and/or drier climatic conditions, and to a minor degree to land-use changes. Our results therefore provide valuable insights into vegetation changes in peat bogs, also with respect to bog response to ongoing and future climatic changes.

  3. Increased tree establishment in Lithuanian peat bogs--insights from field and remotely sensed approaches.

    PubMed

    Edvardsson, Johannes; Šimanauskienė, Rasa; Taminskas, Julius; Baužienė, Ieva; Stoffel, Markus

    2015-02-01

    Over the past century an ongoing establishment of Scots pine (Pinus sylvestris L.), sometimes at accelerating rates, is noted at three studied Lithuanian peat bogs, namely Kerėplis, Rėkyva and Aukštumala, all representing different degrees of tree coverage and geographic settings. Present establishment rates seem to depend on tree density on the bog surface and are most significant at sparsely covered sites where about three-fourth of the trees have established since the mid-1990s, whereas the initial establishment in general was during the early to mid-19th century. Three methods were used to detect, compare and describe tree establishment: (1) tree counts in small plots, (2) dendrochronological dating of bog pine trees, and (3) interpretation of aerial photographs and historical maps of the study areas. In combination, the different approaches provide complimentary information but also weigh up each other's drawbacks. Tree counts in plots provided a reasonable overview of age class distributions and enabled capturing of the most recently established trees with ages less than 50 years. The dendrochronological analysis yielded accurate tree ages and a good temporal resolution of long-term changes. Tree establishment and spread interpreted from aerial photographs and historical maps provided a good overview of tree spread and total affected area. It also helped to verify the results obtained with the other methods and an upscaling of findings to the entire peat bogs. The ongoing spread of trees in predominantly undisturbed peat bogs is related to warmer and/or drier climatic conditions, and to a minor degree to land-use changes. Our results therefore provide valuable insights into vegetation changes in peat bogs, also with respect to bog response to ongoing and future climatic changes. PMID:25310886

  4. Hydrologic conditions in the Klatt Bog area, Anchorage, Alaska

    USGS Publications Warehouse

    Glass, R.L.

    1986-01-01

    Klatt Bog is a 2.3 sq mi wetland in Anchorage, Alaska which provides habitat for many wildlife species but also offers potential sites for residential, commercial, and agricultural developments. Precipitation, the main source of water for the area, averages 15 in/yr; during the 1983 study period, precipitation was 12.16 inches. Estimates of evapotranspiration, considered to be the major component of water outflow, range from 10 to 20 inches. Surface runoff and groundwater outflow during 1983 are estimated to be 2.8 and < 0.2 inches, respectively. During summer, most of the runoff is derived from groundwater discharge near the upgradient eastern edge of the wetland. The wetland 's aquifer system is composed of fibrous peat which overlies a poorly permeable layer of silt and clay. The aquifer is recharged by infiltration of precipitation and inflow of groundwater from upland areas east of the wetland. During 1983 the water table was at or within 3 ft of land surface in most areas and its seasonal fluctuation was < 2 feet. Water collected from four shallow observation wells, two ponds, and two sites on a stream had concentrations of dissolved iron ranging from 2,300 to 6,100 micrograms/L. (Author 's abstract)

  5. Bog Manganese Ore: A Resource for High Manganese Steel Making

    NASA Astrophysics Data System (ADS)

    Pani, Swatirupa; Singh, Saroj K.; Mohapatra, Birendra K.

    2016-06-01

    Bog manganese ore, associated with the banded iron formation of the Iron Ore Group (IOG), occurs in large volume in northern Odisha, India. The ore is powdery, fine-grained and soft in nature with varying specific gravity (2.8-3.9 g/cm3) and high thermo-gravimetric loss, It consists of manganese (δ-MnO2, manganite, cryptomelane/romanechite with minor pyrolusite) and iron (goethite/limonite and hematite) minerals with sub-ordinate kaolinite and quartz. It shows oolitic/pisolitic to globular morphology nucleating small detritus of quartz, pyrolusite/romanechite and hematite. The ore contains around 23% Mn and 28% Fe with around 7% of combined alumina and silica. Such Mn ore has not found any use because of its sub-grade nature and high iron content, and is hence considered as waste. The ore does not respond to any physical beneficiation techniques because of the combined state of the manganese and iron phases. Attempts have been made to recover manganese and iron value from such ore through smelting. A sample along with an appropriate charge mix when processed through a plasma reactor, produced high-manganese steel alloy having 25% Mn within a very short time (<10 min). Minor Mn content from the slag was recovered through acid leaching. The aim of this study has been to recover a value-added product from the waste.

  6. Polyphenolic Compositions and Chromatic Characteristics of Bog Bilberry Syrup Wines.

    PubMed

    Liu, Shu-Xun; Yang, Hang-Yu; Li, Si-Yu; Zhang, Jia-Yue; Li, Teng; Zhu, Bao-Qing; Zhang, Bo-Lin

    2015-11-04

    Phenolic compounds determine the color quality of fruit wines. In this study, the phenolic compound content and composition, color characteristics and changes during 6 months of bottle aging were studied in wines fermented with bog bilberry syrup under three different pHs. The total anthocyanins and total phenols were around 15.12-16.23 mg/L and 475.82 to 486.50 mg GAE/L in fresh wines and declined 22%-31% and about 11% in bottle aged wines, respectively. In fresh wines, eight anthocyanins, six phenolic aids and 14 flavonols, but no flavon-3-ols were identified; Malvidin-3-O-glucoside, petunidin-3-O-glucoside and delphinium-3-O-glucoside were the predominant pigments; Chlorogentic acid was the most abundant phenolic acid, and quercetin-3-O-galactoside and myricetin-3-O-galactoside accounted for nearly 90% of the total flavonols. During 6 months of bottle storage, the amounts of all the monomeric anthocyanins and phenolic acids were reduced dramatically, while the glycosidyl flavonols remained constant or were less reduced and their corresponding aglycones increased a lot. The effects of aging on blueberry wine color were described as the loss of color intensity with a dramatic change in color hue, from initial red-purple up to final red-brick nuances, while the pH of the fermentation matrix was negatively related to the color stability of aged wine.

  7. Identifying the sources and timing of ancient and medieval atmospheric lead pollution in England using a peat profile from Lindow bog, Manchester.

    PubMed

    Le Roux, Gaël; Weiss, Dominik; Grattan, John; Givelet, Nicolas; Krachler, Michael; Cheburkin, Andriy; Rausch, Nicole; Kober, Bernd; Shotyk, William

    2004-05-01

    A peat core from Lindow bog near Manchester, England, was precisely cut into 2 cm slices to provide a high-resolution reconstruction of atmospheric Pb deposition. Radiocarbon and (210)Pb age dates show that the peat core represents the period ca. 2000 BC to AD 1800. Eleven radiocarbon age dates of bulk peat samples reveal a linear age-depth relationship with an average temporal resolution of 18.5 years per cm, or 37 years per sample. Using the Pb/Ti ratio to calculate the rates of anthropogenic, atmospheric Pb deposition, the profile reveals Pb contamination first appearing in peat samples dating from ca. 900 BC which clearly pre-date Roman mining activities. Using TIMS, MC-ICP-MS, and SF-ICP-MS to measure the isotopic composition of Pb, the (208)Pb/(206)Pb and (206)Pb/(207)Pb data indicate that English ores were the predominant sources during the pre-Roman, Roman, and Medieval Periods. The study shows that detailed studies of peat profiles from ombrotrophic bogs, using appropriate preparatory and analytical methods, can provide new insight into the timing, intensity, and predominant sources of atmospheric Pb contamination, even in samples dating from ancient times.

  8. Identifying the sources and timing of ancient and medieval atmospheric lead pollution in England using a peat profile from Lindow bog, Manchester.

    PubMed

    Le Roux, Gaël; Weiss, Dominik; Grattan, John; Givelet, Nicolas; Krachler, Michael; Cheburkin, Andriy; Rausch, Nicole; Kober, Bernd; Shotyk, William

    2004-05-01

    A peat core from Lindow bog near Manchester, England, was precisely cut into 2 cm slices to provide a high-resolution reconstruction of atmospheric Pb deposition. Radiocarbon and (210)Pb age dates show that the peat core represents the period ca. 2000 BC to AD 1800. Eleven radiocarbon age dates of bulk peat samples reveal a linear age-depth relationship with an average temporal resolution of 18.5 years per cm, or 37 years per sample. Using the Pb/Ti ratio to calculate the rates of anthropogenic, atmospheric Pb deposition, the profile reveals Pb contamination first appearing in peat samples dating from ca. 900 BC which clearly pre-date Roman mining activities. Using TIMS, MC-ICP-MS, and SF-ICP-MS to measure the isotopic composition of Pb, the (208)Pb/(206)Pb and (206)Pb/(207)Pb data indicate that English ores were the predominant sources during the pre-Roman, Roman, and Medieval Periods. The study shows that detailed studies of peat profiles from ombrotrophic bogs, using appropriate preparatory and analytical methods, can provide new insight into the timing, intensity, and predominant sources of atmospheric Pb contamination, even in samples dating from ancient times. PMID:15152320

  9. Relationship between peat geochemistry and depositional environments, Cranberry Island, Maine

    USGS Publications Warehouse

    Raymond, R.; Cameron, C.C.; Cohen, A.D.

    1987-01-01

    The Heath, Great Cranberry Island, Maine, offers a unique locality for studying lateral and vertical relationships between radically different peat types within 1 km2. The majority of The Heath is a Sphagnum moss-dominated raised bog. Surrounding the raised bog is a swamp/marsh complex containing grass, sedge, Sphagnum moss, alder, tamarack, and skunk cabbage. Swamp/ marsh-deposited peat occurs both around the margins of The Heath and under Sphagnum-dominated peat, which was deposited within the raised bog. A third peat type, dominated by herbaceous aquatics, is present underlying the swamp/marsh-dominated peat but is not present as a dominant botanical community of The Heath. The three peat types have major differences in petrographic characteristics, ash contents, and associated minerals. Sulfur contents range from a low of 0.19 wt.% (dry) within the raised bog to a high of 4.44 wt% (dry) near the west end of The Heath, where swamp/marsh peat occurring directly behind a storm beach berm has been influenced by marine waters. The presence of major geochemical variations within a 1-km2 peat deposit suggests the need for in-depth characterization of potential peat resources prior to use. ?? 1987.

  10. Fen to bog transitions in high latitudes: what conditions lead to permafrost aggradation?

    NASA Astrophysics Data System (ADS)

    Treat, C. C.; Jones, M.; Loisel, J.

    2014-12-01

    Northern high-latitude peatlands accumulated an estimated 436 Gt of carbon over the Holocene. Vegetation changes, such as the succession from fen to bog species, are often clearly visible in peat profiles and can be caused by organic matter accumulation or by changes in regional climate. Most peatlands developed during the early Holocene as fens under a climate that was warmer than today due to a summer insolation maximum. Subsequent transition to bogs facilitated permafrost aggradation during the mid- to late-Holocene. Teasing out permafrost aggradation in peat cores remains a challenge, as they often resemble dry bogs. However, in many locations permafrost aggradation can be assumed especially if thermokarst is evident later in the peat record (i.e., an abrupt transition from dry bog or plateau peat to wet Sphagnum riparium or even fen peat). We used a database of existing peat core records from around the northern high latitudes to determine transition of fen to bog from plant macrofossils and determined permafrost aggradation from both plant macrofossils and physical peat properties to improve constraints on methane emissions from northern peatlands throughout the Holocene. Here, we examine the spatial and temporal trends of the fen to bog transition and permafrost aggradation in the northern high latitude regions by compiling a database of existing records of macrofossil assemblages and peat properties (carbon, nitrogen, and bulk density). We find that the timing of the fen-to-bog transition varied throughout the northern high latitudes, from 5200 yr BP in Alaska and Western Canada to < 1000 yr BP in Eastern Canada and Siberia. Similarly, the first occurrences of permafrost aggradation varied across the high latitudes, ranging from 4000 yr BP in Western Canada to the Little Ice Age in southern regions and parts of Western Siberia. The spatial and temporal differences in the fen to bog transition and permafrost aggradation suggest that methane emissions

  11. A new peat bog testate amoeba transfer function and quantitative palaeohydrological reconstructions from southern Patagonia

    NASA Astrophysics Data System (ADS)

    van Bellen, S.; Mauquoy, D.; Payne, R.; Roland, T. P.; Hughes, P. D.; Daley, T. J.; Street-Perrot, F. A.; Loader, N.

    2013-12-01

    Testate amoebae have been used extensively as proxies for environmental change and palaeoclimate reconstructions in European and North American peatlands. The presence of these micro-organisms in surface samples is generally significantly linked to the local water table depth (WTD) and preservation of the amoeba shells downcore allows for millennial length water table reconstructions. Peat bog archive records in southern Patagonia are increasingly the focus of palaeoecological research due to the possibility of detecting changes in the Southern Westerlies. These Sphagnum magellanicum-dominated peat bogs are characterised by a wide range of water table depths, from wet hollows to high hummocks (>100 cm above the water table). Here we present the first transfer function for this region along with ~2k-year palaeorecords from local peat bogs. A modern dataset (155 samples) was sampled along transects from five bogs in 2012 and 2013. Measurements of WTD, pH and conductivity were taken for all samples. The transfer function model was based on the 2012 dataset, while the 2013 samples served as an independent test set to validate the model. Besides the standard leave-one-out cross-validation, we applied leave-one-site-out and leave-one transect-out cross-validation, which are effective means of verifying the degree of clustering in the dataset. To ensure that the environmental gradient had been evenly sampled we quantified the root-mean-squared error of prediction (RMSEP) individually for segments of this gradient. Ordinations showed a clear hydrological gradient in amoeba assemblages, with the dominant Assulina muscorum at the dry end and Amphitrema wrightianum and Difflugia globulosa at the wet end. Canonical correspondence analysis showed that WTD was the most important environmental variable, accounting for 18% of the variance in amoeba assemblages. A weighted averaging-partial least squares model showed best performance in cross-validation, using the 2013 data as an

  12. CO2 and CH4 fluxes of contrasting pristine bogs in southern Patagonia (Tierra del Fuego, Argentina)

    NASA Astrophysics Data System (ADS)

    Münchberger, Wiebke; Blodau, Christian; Kleinebecker, Till; Pancotto, Veronica

    2015-04-01

    South Patagonian peatlands cover a wide range of the southern terrestrial area and thus are an important component of the terrestrial global carbon cycle. These extremely southern ecosystems have been accumulating organic material since the last glaciation up to now and are - in contrast to northern hemisphere bogs - virtually unaffected by human activities. So far, little attention has been given to these pristine ecosystems and great carbon reservoirs which will potentially be affected by climate change. We aim to fill the knowledge gap in the quantity of carbon released from these bogs and in what controls their fluxes. We study the temporal and spatial variability of carbon fluxes in two contrasting bog ecosystems in southern Patagonia, Tierra del Fuego. Sphagnum-dominated bog ecosystems in Tierra del Fuego are similar to the ones on the northern hemisphere, while cushion plant-dominated bogs can almost exclusively be found in southern Patagonia. These unique cushion plant-dominated bogs are found close to the coast and their occurrence changes gradually to Sphagnum-dominated bogs with increasing distance from the coast. We conduct closed chamber measurements and record relevant environmental variables for CO2 and CH4 fluxes during two austral vegetation periods from December to April. Chamber measurements are performed on microforms representing the main vegetation units of the studied bogs. Gas concentrations are measured with a fast analyzer (Los Gatos Ultraportable Greenhouse Gas Analyzer) allowing to accurately record CH4 fluxes in the ppm range. We present preliminary results of the carbon flux variability from south Patagonian peat bogs and give insights into their environmental controls. Carbon fluxes of these two bog types appear to be highly different. In contrast to Sphagnum-dominated bogs, cushion plant-dominated bogs release almost no CH4 while their CO2 flux in both, photosynthesis and respiration, can be twice as high as for Sphagnum

  13. Processes in the pore waters of peat deposits

    SciTech Connect

    Levshenko, T.V.; Efremova, A.G.; Galkina, Z.M.; Surkova, T.E.; Tolstov, K.A.

    1983-01-01

    The composition of the waters of modern peat bogs that have developed in the intracontinental regions under the conditions of bogs of the high-moor, mixed, and lowmoor types have been investigated for the case of a number of peat deposits of the Smolensk, Volgorad, and Pskov provinces. During the work the pH of the deposits and the C1-, Alk, SO/sup 2/-, Ca/sup 2 +/, Mg/sup 2 +/, K- contents of the pore water of modern peat beds were studied. The thickness of the deposits studied amounted to 5-7 m. Samples were taken every 0.5 m in depth. The water was separated from the deposits by pressing out.

  14. The Sphagnum microbiome supports bog ecosystem functioning under extreme conditions.

    PubMed

    Bragina, Anastasia; Oberauner-Wappis, Lisa; Zachow, Christin; Halwachs, Bettina; Thallinger, Gerhard G; Müller, Henry; Berg, Gabriele

    2014-09-01

    Sphagnum-dominated bogs represent a unique yet widely distributed type of terrestrial ecosystem and strongly contribute to global biosphere functioning. Sphagnum is colonized by highly diverse microbial communities, but less is known about their function. We identified a high functional diversity within the Sphagnum microbiome applying an Illumina-based metagenomic approach followed by de novo assembly and MG-RAST annotation. An interenvironmental comparison revealed that the Sphagnum microbiome harbours specific genetic features that distinguish it significantly from microbiomes of higher plants and peat soils. The differential traits especially support ecosystem functioning by a symbiotic lifestyle under poikilohydric and ombrotrophic conditions. To realise a plasticity-stability balance, we found abundant subsystems responsible to cope with oxidative and drought stresses, to exchange (mobile) genetic elements, and genes that encode for resistance to detrimental environmental factors, repair and self-controlling mechanisms. Multiple microbe-microbe and plant-microbe interactions were also found to play a crucial role as indicated by diverse genes necessary for biofilm formation, interaction via quorum sensing and nutrient exchange. A high proportion of genes involved in nitrogen cycle and recycling of organic material supported the role of bacteria for nutrient supply. 16S rDNA analysis indicated a higher structural diversity than that which had been previously detected using PCR-dependent techniques. Altogether, the diverse Sphagnum microbiome has the ability to support the life of the host plant and the entire ecosystem under changing environmental conditions. Beyond this, the moss microbiome presents a promising bio-resource for environmental biotechnology - with respect to novel enzymes or stress-protecting bacteria. PMID:25113243

  15. Hydrology controls methane and nitrous oxide fluxes in swamp and bog forests

    NASA Astrophysics Data System (ADS)

    Mander, Ülo; Pärn, Jaan; Maddison, Martin; Soosaar, Kaido; Salm, Jüri-Ott; Sohar, Kristina; Teemusk, Alar

    2016-04-01

    We used data from a global soil, and N2O and CH4 gas sampling campaign. The objective was to analyse N2O and CH4 emissions related to peat conditions in swamp and bog forests. Altogether, we studied 21 swamp and bog forest sites under various climates: 3 alder swamps and 3 artificially drained bog pine forests in Estonia (Jan.-Dec. 2009), 2 bog forests in Transylvania/Romania (Apr. 2012 & June 2014), 3 cypress swamps in the Everglades (Apr. & Dec. 2013), 2 bog forests in West Siberia (July 2013) and a bog forest in Tasmania (Jan.-Feb. 2014). The N2O and CH4 effluxes were measured during 5-6 days with 8-10 opaque static chambers per site. Soil samples were taken for further analysis of pHKCl, NO3-N, NH4-N, soluble P, K, Ca and Mg, totN and C. Groundwater was measured from sampling wells. The most significant independent factor for site average CH4 fluxes was groundwater depth - an exponential relationship; R2=0.42; p=0.0007; n=21. The N2O fluxes showed a decreasing (power) relationship with the C/N ratio - R2=0.53; p<0.0001; n=21. Related to groundwater level, the N2O fluxes peak at around -40cm. Variation in greenhouse gas fluxes was largest at the more favourable conditions - at optimal water table (+5 to -20cm) for CH4 and at low C/N for N2O. The results agree with previous literature but they are the first to draw such conclusions from a global campaign following a uniform protocol.

  16. Atmospheric lead and heavy metal pollution records from a Belgian peat bog spanning the last two millenia: human impact on a regional to global scale.

    PubMed

    De Vleeschouwer, François; Gérard, Laëtitia; Goormaghtigh, Catherine; Mattielli, Nadine; Le Roux, Gaël; Fagel, Nathalie

    2007-05-15

    Europe has been continuously polluted throughout the last two millennia. During the Roman Empire, these pollutions were mainly from ore extraction and smelting across Europe. Then, during the Middle Ages and the Early times of Industrial revolution (i.e. 1750), these pollutions extended to coal burning and combustion engine. Belgian ombrotrophic peat bogs have proved an effective archive of these pollutants and provide the opportunity to reconstruct the history of atmospheric deposition in NW Europe. The results of recent and past trace metal accumulation and Pb isotopes from a one-meter peat core (in the Misten peat bog) have been derived using XRF and Nu-plasma MC-ICP-MS. Combined with (14)C and (210)Pb dates these data have enabled us to trace fluxes in anthropogenic pollution back to original Roman times. Several periods of well-known Pb pollution events are clearly recorded including the Early and Late Roman Empire, the Middle Ages and the second industrial revolution. Also recorded is the introduction of leaded gasoline, and more recently the introduction of unleaded gasoline. Lead isotopes in this site have also enabled us to fingerprint several regional and global sources of anthropogenic particles.

  17. Interactions between Nitrogen Fixation and Methane Cycling in Northern Minnesota Peat Bogs

    NASA Astrophysics Data System (ADS)

    Warren, M. J.; Gaby, J. C.; Lin, X.; Morton, P. L.; Kostka, J. E.; Glass, J. B.

    2014-12-01

    Peatlands cover only 3% of the Earth's surface, yet store a third of soil carbon. Increasing global temperatures have the potential to change peatlands from a net sink to a net source of atmospheric carbon. N is a limiting nutrient in oligotrophic Sphagnum-dominated peatlands and biological N2 fixation likely supplies a significant but unknown fraction of N inputs. Moreover, environmental controls on diazotrophic community composition in N-limited peatlands are poorly constrained. Thus, improved understanding of feedbacks between the CH4 and N cycles is critical for predicting future changes to CH4 flux from peat bogs. We coupled measurements of N2 fixation activity measured by the acetylene (C2H2) reduction assay (ARA) with molecular analyses of expression and diversity of nifH genes encoding the molybdenum (Mo)-containing nitrogenase from two peat bogs in the Marcell Experimental Forest, Minnesota, USA. The top 10 cm of peat was sampled from the high CH4 flux S1 bog and the low CH4 flux Zim bog in April and June 2014. Despite similar N concentrations in the top 10 cm of both bogs (0.5-1.0 μM NO2-+NO3- and 2-3 μM NH4+), the S1 bog displayed variable ARA activity (1-100 nmol C2H4 h-1 g-1) whereas the Zim bog had consistently low ARA activity (<1 nmol C2H4 h-1 g-1). Highest ARA activity was measured in June from S1 bog hollows with higher moisture content incubated without O2 in the light (20-100 nmol C2H4 h-1 g-1). Dissolved Fe (1-25 μM) was higher in hollow vs. hummock samples, and at S1 vs. Zim bog, while dissolved V (4-14 nM) was consistently higher than Mo (1-4 nM), suggesting that alternative V or Fe-containing nitrogenases might be present in these bogs. In contrast, Cu, an essential micronutrient for aerobic methanotrophs, was higher in hummocks (25-48 nM) than hollows (6-17 nM). The facultative methanotroph Methylocella was the dominant diazotroph in the S1 bog based on high throughput next generation sequencing of nifH cDNA amplicons. Given previous

  18. Nutrient load can lead to enhanced CH4 fluxes through changes in vegetation, peat surface elevation and water table depth in ombrotrophic bog

    NASA Astrophysics Data System (ADS)

    Juutinen, Sari; Bubier, Jill; Larmola, Tuula; Humphreys, Elyn; Arnkil, Sini; Roy, Cameron; Moore, Tim

    2016-04-01

    Atmospheric nitrogen (N) deposition has led to nutrient enrichment in wetlands, particularly in temperate areas, affecting plant community composition, carbon (C) cycling, and microbial dynamics. It is vital to understand the temporal scales and mechanisms of the changes, because peatlands are long-term sinks of C, but sources of methane (CH4), an important greenhouse gas. Rainwater fed (ombrotrophic) bogs are considered to be vulnerable to nutrient loading due to their natural nutrient poor status. We fertilized Mer Bleue Bog, a Sphagnum moss and evergreen shrub-dominated ombrotrophic bog near Ottawa, Ontario, now for 11-16 years with N (NO3 NH4) at 0.6, 3.2, and 6.4 g N m-2 y-1 (~5, 10 and 20 times ambient N deposition during summer months) with and without phosphorus (P) and potassium (K). Treatments were applied to triplicate plots (3 x 3 m) from May - August 2000-2015 and control plots received distilled water. We measured CH4 fluxes with static chambers weekly from May to September 2015 and peat samples were incubated in laboratory to measure CH4 production and consumption potentials. Methane fluxes at the site were generally low, but after 16 years, mean CH4 emissions have increased and more than doubled in high nitrogen addition treatments if P and K input was also increased (3.2 and 6.4 g N m-2yr-1 with PK), owing to drastic changes in vegetation and soil moisture. Vegetation changes include a loss of Sphagnum moss and introduction of new species, typical to minerogenic mires, which together with increased decomposition have led to decreased surface elevation and to higher water table level relative to the surface. The trajectories indicate that the N only treatments may result in similar responses, but only over longer time scales. Elevated atmospheric deposition of nutrients to peatlands may increase loss of C not only due to changes in CO2 exchange but also due to enhanced CH4 emissions in peatlands through a complex suite of feedbacks and interactions

  19. Role and Responsibility of Board of Governors [BOG] in Ensuring Educational Quality in Colleges & Universities

    ERIC Educational Resources Information Center

    Naik, B. M.

    2012-01-01

    The paper presents in brief the need and importance of effective, imaginative and responsible governing boards in colleges and universities, so as to ensure educational quality. BOG should engage fruitfully with the principal and activities in college/ university. UGC, AICTE have now prescribed creation of effective boards for both government and…

  20. Lake or bog? Reconstructing baseline ecological conditions for the protected Galápagos Sphagnum peatbogs

    NASA Astrophysics Data System (ADS)

    Coffey, Emily E. D.; Froyd, Cynthia A.; Willis, Katherine J.

    2012-10-01

    This paper documents the first 10,000 year old plant macrofossil record of vegetation changes on the central island of Santa Cruz, providing information on Sphagnum bog vegetation patterns, local extinction of key taxa, and temporal successions in the Galápagos humid highlands. Vegetation change is reconstructed through examination of Holocene sedimentary sequences obtained from three Sphagnum bogs located within volcanic caldera forming the high elevation central ridge system of Santa Cruz Island. Results indicate that these specialized Sphagnum bog ecosystems are dynamic and have undergone considerable changes in vegetation composition, transitioning from diverse hygrophilous herbs and submerged aquatic ecosystems to drier Sphagnum/Pteridium bog systems, during the last 10,000 cal yr BP. Additionally a new aquatic genus previously undocumented on the islands, Elatine, was discovered at two of the study sites, but it is now extinct on the archipelago. Some of the observed vegetation successions may have been driven by climatic shifts occurring within the eastern equatorial Pacific (EEP). Other drivers including anthropogenic change are also considered significant over the last hundred years, placing strain on this naturally dynamic system. This study helps reveal patterns of change in the humid highlands over the last 10,000 cal yr BP regarding vegetation variability, climatic shifts, the historical influence of fire, tortoise disturbance, and recent anthropogenic impacts on the island.

  1. Ecology of southeastern shrub bogs (pocosins) and Carolina bays: a community profile

    SciTech Connect

    Sharitz, R.R.; Gibbons, J.W.

    1982-11-01

    Shrub bogs of the Southeast occur in areas of poorly developed internal drainage that typically but not always have highly developed organic or peat soils. Pocosins and Carolina bays are types or subclasses of shrub bogs on the coastal plains of the Carolinas and Georgia. They share roughly the same distribution patterns, soil types, floral and faunal species composition and other community attributes, but differ in geological formation. Carolina bays may contain pocosin as well as other communities, but are defined more by their unique elliptical shape and geomorphometry. The pocosin community is largely defined by its vegetation, a combination of a dense shrub understory and a sparser canopy. The community is part of a complex successional sequence of communities (sedge bogs, savannas, cedar bogs, and bay forests) that may be controlled by such factors as fire, hydroperiod, soil type, and peat depth. Pocosins and Carolina bays harbor a number of animal groups and may be locally important in their ecology. Although few species are endemic to these habitats, they may provide important refuges for a number of species. These communities are simultaneously among the least understood and most rapidly disappearing habitats of the Southeast. Forestry and agricultural clearage are current impacts.

  2. A probe for sampling interstitial waters of stream sediments and bog soils

    USGS Publications Warehouse

    Nowlan, G.A.; Carollo, C.

    1974-01-01

    A probe for sampling interstitial waters of stream sediments and bog soils is described. Samples can be obtained within a stratigraphic interval of 2-3 cm, to a depth of 60-80 cm, and with little or no contamination of the samples by sediment or air. ?? 1974.

  3. Peat bog Records of Atmospheric Dust fluxes - Holocene palaeoenvironmental and paleoclimatic implications for South America

    NASA Astrophysics Data System (ADS)

    De Vleeschouwer, François; Vanneste, Heleen; Bertrand, Sébastien; Coronata, Andrea; Gaiero, Diego; Le Roux, Gael

    2013-04-01

    Little attention has been given to pre-anthropogenic signals recorded in peat bogs, especially in the Southern Hemisphere. Yet they are important to 1/ better understand the different particle sources during the Holocene and 2/ to tackle the linkage between atmospheric dust loads and climate change and 3/ to better understand the impact of dust on Holocene palaeoclimate and palaeoenvironments in a critical area for ocean productivity. In the PARAD project, we will explore the use of a broad range of trace elements and radiogenic isotopes (Pb, Nd, Hf) as dust proxies. Coupling these findings with biological proxies (plant macrofossils, pollen) and detailed age-depth modelling, we expect not only to identify and interpret new links between atmospheric dust chemistry and climate change. In this contribution, we will present the preliminary results on two peat records of natural atmospheric dust using the elemental and isotopic signature in Tierra del Fuego. Preliminary results on two peat sections covering the Holocene (Karukinka Bog, Chile, 8kyrs and Harberton bog, Argentina, 14kyrs) will be discussed. This encompasses density, ash content, elemental and isotopic geochemistry, macrofossil determination and radiocarbon dating. More specifically, Karukinka bog display several mineral peaks, which possible origin (soil particles, volcanism, cosmogenic dusts, marine aerosols…) will be discussed here as well as in Vanneste et al. (this conference, session Aeolian dust: Initiator, Player, and Recorder of Environmental Change).

  4. Small is beautiful: why microtopography should be included in bog hydrology

    NASA Astrophysics Data System (ADS)

    Appels, Willemijn; van der Ploeg, Martine; Oosterwoud, Marieke; Cirkel, Gijsbert; van der Zee, Sjoerd; Witte, Jan-Philip

    2014-05-01

    Microtopography can have a large effect on flow processes at the soil surface and the composition of soil water. In peat areas, microtopography is shaped by differences in species, the growth rate and transpiration of the vegetation, and the amount of water flowing from higher areas. Microtopography is often represented by a roughness parameter in hillslope hydrological models. In areas without a strong topographical gradient however, microtopography may be underestimated when accumulated in a single parameter, especially in the presence of shallow groundwater systems. In this study, we review the intricate relationships between microtopography, surface runoff, and ecohydrology in systems featuring shallow water tables. In an analogy to surface runoff, the hydrology of a raised bog can be described as a combination of open water flow on a saturated medium, instead of the traditional acrotelm-catotelm concept that only acknowledges the saturated medium. We explored water flow through the microtopography of a raised bog with a simple conceptual model that accounts explicitly for microtopographic features and the changing flow directions these may cause. With this approach we were able to investigate the activation of fast flow paths on different areas of the bog as a function of their wetness level and bog-specific morphological features, such as hummocks and hollows. Our type of approach could be used to improve the understanding of the spatial and temporal variability of rainfall-runoff responses on raised bogs. In addition, similar approaches could be used to investigate how various runoff regimes affect the mixing of water with different chemical signatures, another driver of variations of the occurrence of plant species.

  5. Andromeda polifolia and Oxycoccus microcarpus as pollution indicators for ombrotrophic bogs in the Western Sudety Mountains (SW Poland).

    PubMed

    Wojtuń, Bronisław; Samecka-Cymerman, Aleksandra; Kolon, Krzysztof; Klink, Agnieszka; Kempers, Alexander J

    2013-01-01

    Concentrations of the elements Cd, Cr, Cu, Fe, Li, Mn, N, Ni, Pb and Zn in Andromeda polifolia, Oxycoccus microcarpus and in the peat in which these plants grew were measured in the Western Sudety (Karkonosze and Izerskie Mts., SW Poland). Of both the investigated plant fruit, O. microcarpus harvested from wild populations are commonly used as medicines. Samples from ombrotrophic bogs were investigated within the area influenced by exhausts of the former Black Triangle, one of the most heavily industrialized and polluted areas in Europe. A. polifolia and O. microcarpus growing at the highest elevations contained the highest Cu, Li, Ni, Mn and Zn concentrations and in addition O. microcarpus also contained the highest Cr concentrations. Both the investigated species have wide circumpolar distribution in ombrotrophic mires of the Northern hemisphere. As this type of mires is nourished solely by atmospheric deposition, the increased metal concentrations in A. polifolia and O. microcarpus may be an indication that their habitats receive an atmospheric input of long-range transported pollution. Our investigation proves that both species are able to accumulate elevated metal levels and may be used in the bioindication of the metal status in ombrotrophic mires. Controlling the collection of O. microcarpus fruit for consumption and medicinal purposes is recommended as this species can accumulate increased metal levels. However, further more detailed studies are necessary to verify the inner translocation of metals into fruit.

  6. Andromeda polifolia and Oxycoccus microcarpus as pollution indicators for ombrotrophic bogs in the Western Sudety Mountains (SW Poland).

    PubMed

    Wojtuń, Bronisław; Samecka-Cymerman, Aleksandra; Kolon, Krzysztof; Klink, Agnieszka; Kempers, Alexander J

    2013-01-01

    Concentrations of the elements Cd, Cr, Cu, Fe, Li, Mn, N, Ni, Pb and Zn in Andromeda polifolia, Oxycoccus microcarpus and in the peat in which these plants grew were measured in the Western Sudety (Karkonosze and Izerskie Mts., SW Poland). Of both the investigated plant fruit, O. microcarpus harvested from wild populations are commonly used as medicines. Samples from ombrotrophic bogs were investigated within the area influenced by exhausts of the former Black Triangle, one of the most heavily industrialized and polluted areas in Europe. A. polifolia and O. microcarpus growing at the highest elevations contained the highest Cu, Li, Ni, Mn and Zn concentrations and in addition O. microcarpus also contained the highest Cr concentrations. Both the investigated species have wide circumpolar distribution in ombrotrophic mires of the Northern hemisphere. As this type of mires is nourished solely by atmospheric deposition, the increased metal concentrations in A. polifolia and O. microcarpus may be an indication that their habitats receive an atmospheric input of long-range transported pollution. Our investigation proves that both species are able to accumulate elevated metal levels and may be used in the bioindication of the metal status in ombrotrophic mires. Controlling the collection of O. microcarpus fruit for consumption and medicinal purposes is recommended as this species can accumulate increased metal levels. However, further more detailed studies are necessary to verify the inner translocation of metals into fruit. PMID:23445412

  7. High potential of nitrogen fixation in pristine, ombrotrophic bogs in Southern Patagonia

    NASA Astrophysics Data System (ADS)

    Knorr, Klaus-Holger; Horn, Marcus A.; Bahamonde Aguilar, Nelson A.; Borken, Werner

    2015-04-01

    Nitrogen (N) input in pristine peatlands occurs via natural input of inorganic N through atmospheric deposition or biological dinitrogen (N2) fixation. However, N2 fixation is to date mostly attributed to bacteria and algae associated to Sphagnum and its contribution to plant productivity and peat buildup has been often underestimated in previous studies. Based on net N storage, exceptionally low N deposition, and high abundance of vascular plants at pristine peatlands in Southern Patagonia, we hypothesized that there must be a high potential of non-symbiotic N2 fixation not limited to the occurrence of Sphagnum. To this end, we chose two ombrotrophic bogs with spots that are dominated either by Sphagnum or by vascular, cushion-forming plants and sampled peat from different depths for incubation with 15N2 to determine N2 fixation potentials. Moreover, we analyzed 15N2 fixation by a nodule-forming, endemic conifer inhabiting the peatlands. Results from 15N2 uptake were compared to the conventional approach to study N2 fixation by the acetylene reduction assay (ARA). Using 15N2 as a tracer, high non-symbiotic N2 fixation rates of 0.3-1.4 μmol N g-1 d-1 were found down to 50 cm under micro-oxic conditions (2 vol.%) in samples from both plots either covered by Sphagnum magellanicum or by vascular cushion plants. Peat N concentrations suggested a higher potential of non-symbiotic N2 fixation under cushion plants, likely because of the availability of easily decomposable organic compounds as substrates and oxic conditions in the rhizosphere. In the Sphagnum plots, high N2 fixation below 10 cm depth would rather reflect a potential fixation that may switch on during periods of low water levels when oxygen penetrates deeper into the peat. 15N natural abundance of live Sphagnum from 0-10 cm pointed to N uptake solely from atmospheric deposition and non-symbiotic N2 fixation. 15N signatures of peat from the cushion plant plots indicated additional N supply from N

  8. Factors affecting the sorption of cesium in a nutrient-poor boreal bog.

    PubMed

    Lusa, M; Bomberg, M; Virtanen, S; Lempinen, J; Aromaa, H; Knuutinen, J; Lehto, J

    2015-09-01

    (135)Cs is among the most important radionuclides in the long-term safety assessments of spent nuclear fuel, due to its long half-life of 2.3 My and large inventory in spent nuclear fuel. Batch sorption experiments were conducted to evaluate the sorption behavior of radiocesium ((134)Cs) in the surface moss, peat, gyttja, and clay layers of 7-m-deep profiles taken from a nutrient-poor boreal bog. The batch distribution coefficient (Kd) values of radiocesium increased as a function of sampling depth. The highest Kd values, with a geometric mean of 3200 L/kg dry weight (DW), were observed in the bottom clay layer and the lowest in the 0.5-1.0 m peat layer (50 L/kg DW). The maximum sorption in all studied layers was observed at a pH between 7 and 9.5. The in situ Kd values of (133)Cs in surface Sphagnum moss, peat and gyttja samples were one order of magnitude higher than the Kd values obtained using the batch method. The highest in situ Kd values (9040 L/kg DW) were recorded for the surface moss layer. The sterilization of fresh surface moss, peat, gyttja and clay samples decreased the sorption of radiocesium by 38%, although the difference was not statistically significant. However, bacteria belonging to the genera Pseudomonas, Paenibacillus, Rhodococcus and Burkholderia isolated from the bog were found to remove radiocesium from the solution under laboratory conditions. The highest biosorption was observed for Paenibacillus sp. V0-1-LW and Pseudomonas sp. PS-0-L isolates. When isolated bacteria were added to sterilized bog samples, the removal of radiocesium from the solution increased by an average of 50% compared to the removal recorded for pure sterilized peat. Our results demonstrate that the sorption of radiocesium in the bog environment is dependent on pH and the type of the bog layer and that common environmental bacteria prevailing in the bog can remove cesium from the solution phase.

  9. Factors affecting the sorption of cesium in a nutrient-poor boreal bog.

    PubMed

    Lusa, M; Bomberg, M; Virtanen, S; Lempinen, J; Aromaa, H; Knuutinen, J; Lehto, J

    2015-09-01

    (135)Cs is among the most important radionuclides in the long-term safety assessments of spent nuclear fuel, due to its long half-life of 2.3 My and large inventory in spent nuclear fuel. Batch sorption experiments were conducted to evaluate the sorption behavior of radiocesium ((134)Cs) in the surface moss, peat, gyttja, and clay layers of 7-m-deep profiles taken from a nutrient-poor boreal bog. The batch distribution coefficient (Kd) values of radiocesium increased as a function of sampling depth. The highest Kd values, with a geometric mean of 3200 L/kg dry weight (DW), were observed in the bottom clay layer and the lowest in the 0.5-1.0 m peat layer (50 L/kg DW). The maximum sorption in all studied layers was observed at a pH between 7 and 9.5. The in situ Kd values of (133)Cs in surface Sphagnum moss, peat and gyttja samples were one order of magnitude higher than the Kd values obtained using the batch method. The highest in situ Kd values (9040 L/kg DW) were recorded for the surface moss layer. The sterilization of fresh surface moss, peat, gyttja and clay samples decreased the sorption of radiocesium by 38%, although the difference was not statistically significant. However, bacteria belonging to the genera Pseudomonas, Paenibacillus, Rhodococcus and Burkholderia isolated from the bog were found to remove radiocesium from the solution under laboratory conditions. The highest biosorption was observed for Paenibacillus sp. V0-1-LW and Pseudomonas sp. PS-0-L isolates. When isolated bacteria were added to sterilized bog samples, the removal of radiocesium from the solution increased by an average of 50% compared to the removal recorded for pure sterilized peat. Our results demonstrate that the sorption of radiocesium in the bog environment is dependent on pH and the type of the bog layer and that common environmental bacteria prevailing in the bog can remove cesium from the solution phase. PMID:26010098

  10. Tracing decadal environmental change in ombrotrophic bogs using diatoms from herbarium collections and transfer functions.

    PubMed

    Poulíčková, Aloisie; Hájková, Petra; Kintrová, Kateřina; Bat'ková, Romana; Czudková, Markéta; Hájek, Michal

    2013-08-01

    Central European mountain bogs, among the most valuable and threatened of habitats, were exposed to intensive human impact during the 20th century. We reconstructed the subrecent water chemistry and water-table depths using diatom based transfer functions calibrated from modern sampling. Herbarium Sphagnum specimens collected during the period 1918-1998 were used as a source of historic diatom samples. We classified samples into hummocks and hollows according to the identity of dominant Sphagnum species, to reduce bias caused by uneven sampling of particular microhabitats. Our results provide clear evidence for bog pollution by grazing during the period 1918-1947 and by undocumented aerial liming in the early 90-ies. We advocate use of herbarized epibryon as a source of information on subrecent conditions in recently polluted mires.

  11. Tracing decadal environmental change in ombrotrophic bogs using diatoms from herbarium collections and transfer functions.

    PubMed

    Poulíčková, Aloisie; Hájková, Petra; Kintrová, Kateřina; Bat'ková, Romana; Czudková, Markéta; Hájek, Michal

    2013-08-01

    Central European mountain bogs, among the most valuable and threatened of habitats, were exposed to intensive human impact during the 20th century. We reconstructed the subrecent water chemistry and water-table depths using diatom based transfer functions calibrated from modern sampling. Herbarium Sphagnum specimens collected during the period 1918-1998 were used as a source of historic diatom samples. We classified samples into hummocks and hollows according to the identity of dominant Sphagnum species, to reduce bias caused by uneven sampling of particular microhabitats. Our results provide clear evidence for bog pollution by grazing during the period 1918-1947 and by undocumented aerial liming in the early 90-ies. We advocate use of herbarized epibryon as a source of information on subrecent conditions in recently polluted mires. PMID:23688732

  12. Functional Diversity of Boreal Bog Plant Species Decreases Seasonal Variation of Ecosystem Carbon Sink Function

    NASA Astrophysics Data System (ADS)

    Korrensalo, A.

    2015-12-01

    Species diversity has been found to decrease the temporal variance of productivity of a plant community, and diversity in species responses to environmental factors seems to make a plant community more stable in changing conditions. Boreal bogs are nutrient poor peatland ecosystems where the number of plant species is low but the species differ greatly in their growth form. In here we aim to assess the role of the variation in photosynthesis between species for the temporal variation in ecosystem carbon sink function. To quantify the photosynthetic properties and their seasonal variation for different bog plant species we measured photosynthetic parameters and stress-inducing chlorophyll fluorescence of vascular plant and Sphagnum moss species in a boreal bog over a growing season. We estimated monthly gross photosynthesis (PG) of the whole study site based on species level light response curves and leaf area development. The estimated PG was further compared with a gross primary production (GPP) estimate measured by eddy covariance (EC) technique. The sum of upscaled PG estimates agreed well with the GPP estimate measured by the EC technique. The contributions of the species and species groups to the ecosystem level PG changed over the growing season. The sharp mid-summer peak in sedge PG was balanced by more stable PG of evergreen shrubs and Sphagna. Species abundance rather than differences in photosynthetic properties between species and growth forms determined the most productive plants on the ecosystem scale. Sphagna had lower photosynthesis and clorophyll fluorescence than vascular plants but were more productive on the ecosystem scale throughout the growing season due to their high areal coverage. These results show that the diversity of growth forms stabilizes the seasonal variation of the ecosystem level PG in an ombrotrophic bog ecosystem. This may increase the resilience of the ecosystem to changing environmental conditions.

  13. CO2 soil fluxes at bog and forest ecosystems in southern taiga of European Russia

    NASA Astrophysics Data System (ADS)

    Ivanov, Dmitrii; Ivanov, Aleksey; Vasenev, Ivan; Kurbatova, Juliya

    2015-04-01

    Bogs and spruce forests are typical natural ecosystems of the southern taiga of European Russia. They play an important role in carbon balance between soil and atmosphere. In the Central Forest Reserve (33°00' E, 56°30' N) for over 15 years conduct research of these processes. One of the research methods of CO2 emissions is the chamber method, which allows to analyze the local variation of the intensity of fluxes and its depending of the type of vegetation, microrelief and meteorological parameters. Period of measurements was 5 months - from June to November 2013-2014. In the bog were investigated 3 areas - pine boggy forest, as well as hummocks and hollows in the middle of bog. As the forest ecosystem was chosen paludified shallow-peat spruce forest. From the data obtained it can be concluded that in all ecosystems were observed 2 periods with a minimum values of CO2 emission: the first - in early July, associated with a high level of ground water and decrease the intensity of decomposition of organic matter, and the second - in November, associated with natural processes and seasonal cooling. The average intensity of CO2 emissions in summer-autumn season between all ecosystems varied greatly: in the boggy pine forest - 500 mgCO2/m2*h), hummocks - 550 mgCO2/m2*h, hollows - 290 mgCO2/m2*h) and paludified shallow-peat spruce forest - 750 mgCO2/m2*h. Based on these researches, it was found that the intensity of CO2 emissions significantly below in the bog than in paludified shallow-peat spruce forest because it is limited by the level of ground water. In the paludified shallow-peat spruce forest, fluxes are more depend on soil temperature and less on the groundwater level.

  14. Factors Controlling Diffusive CO2 Transport and Production in the Cedarburg Bog, Saukville, Wisconsin: Field Observations

    NASA Astrophysics Data System (ADS)

    Joynt, E.; Han, W. S.; Gulbranson, E. L.; Graham, J. P.

    2015-12-01

    Wetland ecosystems are vital components of the carbon cycle containing an estimated 20-30% of the global soil carbon store. The Cedarburg Bog of southeastern Wisconsin boasts a myriad of wetland habitats including the southernmost string bog found in North America. The behavior of carbon dioxide (CO2) in these systems is the response of multiple interdependent variables that are, collectively, not well understood. Modeling this behavior in future climate scenarios requires detailed representation of such relationships within highly diverse environments. In 2014 a LI-COR 8100A automated soil gas flux system was installed in a hollow of the Cedarburg Bog string bog and collectively measured diffusive CO2 concentration and flux. Supplemental groundwater data, soil temperature, and weather data (temperature, pressure, precipitation, etc.) were also included to elucidate correlations between soil CO2 flux/CO2 concentration and external forces. In 2015 field data were complemented with soil moisture data and depth profile sampling of pore water chemistry and stable carbon isotopes from peat and gaseous media in order to discern the source and evolution of CO2 at depth. Preliminary LI-COR data analysis reveals distinct diurnal and seasonal trends; CO2 concentration builds overnight while flux increases during the day, both peaking in mid-summer. Flux events average 405 mg CO2/m2 per hour but reach over 31,800 mg CO2/m2 per hour in a single event and in several instances negative flux events are observed. Correlation significance also yields a wide array of strengths among variables. Initial δ13C data from gaseous CO2 infer, on average, a more positive δ13C signature in the atmosphere compared to the surface and shallow subsurface. Temporal trends of these parameters are similar to one another, becoming depleted in δ13C through time. Further interpretation of data trends will utilize the HYDRUS-1D model to quantify relationships under changing environmental conditions.

  15. Properties and structure of peat humic acids depending on humification and precursor biota in bogs

    NASA Astrophysics Data System (ADS)

    Klavins, Maris; Purmalis, Oskars

    2013-04-01

    Humic substances form most of the organic component of soil, peat and natural waters, but their structure and properties very much differs depending on their source. The aim of this study is to characterize humic acids from raised bog peat profiles to evaluate the homogeneity of humic acids isolated from the bog bodies and study peat humification impact on properties of humic acids. A major impact on the structure of peat humic acids have raised bog biota (dominantly represented by bryophytes of different origin) void of lignin. For characterization of peat humic acids their elemental (CHNOS), functional (-COOH, phenolic OH) analysis, spectroscopic characterization (UV, fluorescence, FTIR, 1H NMR, CP/MAS 13C NMR, ESR) and degradation studies (Py-GC/MS) were done. Peat humic acids (HA) have an intermediate position between the living organic matter and coal organic matter and their structure is formed in a process in which more labile structures (carbohydrates, amino acids, etc.) are destroyed, but thermodynamically more stable aromatic and polyaromatic structures emerge. Comparatively, the studied peat HAs are at the start of the transformation process of living organic matter. Concentrations of carboxyl and phenolic hydroxyl groups changes depending on the depth of peat from which HAs have been isolated: and carboxylic acidity is increasing with depth of peat location and the humification degree. The ability to influence the surface tension of peat humic acids isolated from a well-characterized bog profile demonstrates dependence on age and humification degree. With increase of the humification degree and age of humic acids, their molecular complexity and ability to influence surface tension decreases; even so, the impact of the biological precursor (peat-forming bryophytes and plants) can be identified.

  16. Evaluating cumulative effects of disturbance on the hydrologic function of bogs, fens, and mires

    SciTech Connect

    Siegel, D.I.

    1988-01-01

    Few quantitative studies have been done on the hydrology of fens, bogs, and mires and, consequently, any predictions of the cumulative impacts of disturbances on their hydrologic functions is extremely difficult. Bogs and fens are, in a sense, hydrobiologic systems, and any evaluation of cumulative impacts on them will have to consider the complicated interactions, barely understood, among the wetland hydrology, water chemistry, and biota, and place the effect of individual wetland impacts within the context of the cumulative impacts contributed to the watershed from other geomorphic areas and land uses. It is difficult to evaluate the potential cumulative impacts on wetland hydrology because geologic settings of wetlands are often complex and the methods used to measure wetland stream flow, ground-water flow, and evapotranspiration are inexact. Their very scale makes it difficult to quantify the hydrologic function accurately. The paper reviews current understanding of the hydrologic function of bogs, fens, and mires at different scales and in different physiographic settings, and presents hypotheses on potential cumulative impacts on the hydrologic function that might occur with multiple disturbances.

  17. Methane fluxes during the cold season: distribution and mass transfer in the snow cover of bogs

    NASA Astrophysics Data System (ADS)

    Smagin, A. V.; Shnyrev, N. A.

    2015-08-01

    Fluxes and profile distribution of methane in the snow cover and different landscape elements of an oligotrophic West-Siberian bog (Mukhrino Research Station, Khanty-Mansiisk autonomous district) have been studied during a cold season. Simple models have been proposed for the description of methane distribution in the inert snow layer, which combine the transport of the gas and a source of constant intensity on the soil surface. The formation rates of stationary methane profiles in the snow cover have been estimated (characteristic time of 24 h). Theoretical equations have been derived for the calculation of small emission fluxes from bogs to the atmosphere on the basis of the stationary profile distribution parameters, the snow porosity, and the effective methane diffusion coefficient in the snow layer. The calculated values of methane emission significantly (by 2-3 to several tens of times) have exceeded the values measured under field conditions by the closed chamber method (0.008-0.25 mg C/(m2 h)), which indicates the possibility of underestimating the contribution of the cold period to the annual emission cycle of bog methane.

  18. Potentials and problems of building detailed dust records using peat archives: An example from Store Mosse (the "Great Bog"), Sweden

    NASA Astrophysics Data System (ADS)

    Kylander, Malin E.; Martínez-Cortizas, Antonio; Bindler, Richard; Greenwood, Sarah L.; Mörth, Carl-Magnus; Rauch, Sebastien

    2016-10-01

    Mineral dust deposition is a process often overlooked in northern mid-latitudes, despite its potential effects on ecosystems. These areas are often peat-rich, providing ample material for the reconstruction of past changes in atmospheric deposition. The highly organic (up to 99% in some cases) matrix of atmospherically fed mires, however, makes studying the actual dust particles (grain size, mineralogy) challenging. Here we explore some of the potentials and problems of using geochemical data from conservative, lithogenic elements (Al, Ga, Rb, Sc, Y, Zr, Th, Ti and REE) to build detailed dust records by using an example from the 8900-yr peat sequence from Store Mosse (the "Great Bog"), which is the largest mire complex in the boreo-nemoral region of southern Sweden. The four dust events recorded at this site were elementally distinct, suggesting different dominant mineral hosts. The oldest and longest event (6385-5300 cal yr BP) sees a clear signal of clay input but with increasing contributions of mica, feldspar and middle-REE-rich phosphate minerals over time. These clays are likely transported from a long-distance source (<100 km). While dust deposition was reduced during the second event (5300-4370 cal yr BP), this is the most distinct in terms of its source character with [Eu/Eu∗]UCC revealing the input of plagioclase feldspar from a local source, possibly active during this stormier period. The third (2380-2200 cal yr BP) and fourth (1275-1080 cal yr BP) events are much shorter in duration and the presence of clays and heavy minerals is inferred. Elemental mass accumulation rates reflect these changes in mineralogy where the relative importance of the four dust events varies by element. The broad changes in major mineral hosts, grain size, source location and approximated net dust deposition rates observed in the earlier dust events of longer duration agree well with paleoclimatic changes observed in northern Europe. The two most recent dust events are much

  19. Photosynthetic properties of boreal bog plant species and their contribution to ecosystem level carbon sink

    NASA Astrophysics Data System (ADS)

    Korrensalo, Aino; Hájek, Tomas; Alekseychik, Pavel; Rinne, Janne; Vesala, Timo; Mehtätalo, Lauri; Mammarella, Ivan; Tuittila, Eeva-Stiina

    2016-04-01

    Boreal bogs have a low number of plant species, but a large diversity of growth forms. This heterogeneity might explain the seasonally less varying photosynthetic productivity of these ecosystems compared to peatlands with vegetation consisting of fewer growth forms. The differences in photosynthetic properties within bog species and phases of growing season has not been comprehensively studied. Also the role of different plant species for the ecosystem level carbon (C) sink function is insufficiently known. We quantified the seasonal variation of photosynthetic properties in bog plant species and assessed how this variation accounts for the temporal variation in the ecosystem C sink. Photosynthetic light response of 11 vascular plant and 8 Sphagnum moss species was measured monthly over the growing season of 2013. Based on the species' light response parameters, leaf area development and areal coverage, we estimated the ecosystem level gross photosynthesis rate (PG) over the growing season. The level of upscaled PG was verified by comparing it to the ecosystem gross primary production (GPP) estimate calculated based on eddy covariance (EC) measurements. Although photosynthetic parameters differed within plant species and months, these differences were of less importance than expected for the variation in ecosystem level C sink. The most productive plant species at the ecosystem scale were not those with the highest maximum potential photosynthesis per unit of leaf area (Pmax), but those having the largest areal coverage. Sphagnum mosses had 35% smaller Pmax than vascular plants, but had higher photosynthesis at the ecosystem scale throughout the growing season. The contribution of the bog plant species to the ecosystem level PG differed over the growing season. The seasonal variation in ecosystem C sink was mainly controlled by phenology. Sedge PG had a sharp mid-summer peak, but the PG of evergreen shrubs and Sphagna remained rather stable over the growing season

  20. The new European Competence Centre for Moor and Climate - A European initiative for practical peat bog and climate protection

    NASA Astrophysics Data System (ADS)

    Smidt, Geerd; Tänzer, Detlef

    2013-04-01

    The new European Competence Centre for Moor and Climate (EFMK) is an initiative by different local communities, environmental protection NGOs, agricultural services, and partners from the peat and other industries in Lower Saxony (Germany). The Centre aims to integrate practical peat bog conservation with a focus on green house gas emission after drainage and after water logging activities. Together with our partners we want to break new ground to protect the remaining bogs in the region. Sphagnum mosses will be produced in paludiculture on-site in cooperation with the local peat industry to provide economic and ecologic alternatives for peat products used in horticulture business. Land-use changes are needed in the region and will be stimulated in cooperation with agricultural services via compensation money transfers from environmental protection funds. On a global scale the ideas of Carbon Credit System have to be discussed to protect the peat bogs for climate protection issues. Environmental education is an important pillar of the EFMK. The local society is invited to explore the unique ecosystem and to participate in peat bog protection activities. Future generations will be taught to understand that the health of our peat bogs is interrelated with the health of the local and global climate. Besides extracurricular classes for schools the centre will provide infrastructure for Master and PhD students, as well for senior researchers for applied research in the surrounding moor. International partners in the scientific and practical fields of peat bog ecology, renaturation, green house gas emissions from peat bogs, and environmental policy are invited to participate in the European Competence Center for Moor and Climate.

  1. Raised bogs, a Climate Shift, Cultural Change, and Reduced Solar Activity in the Early First Millennium BC

    NASA Astrophysics Data System (ADS)

    van Geel, B.

    2006-12-01

    Matching of a high resolution sequence of uncalibrated 14C datings with the dendro-calibration curve not only offers improved dating precision, but can also reveal relationships between atmospheric 14C variations and short-term climatic fluctuations caused by variations in solar output. Holocene shifts to cool and wet climate types in the temperate zones often correspond to phases of sharply increasing values of atmospheric radiocarbon, pointing to a link between changing solar activity and climate change. In northwest Europe at ca. 850 BC a sharp climatic shift to cooler, wetter conditions occurred. The shift is reflected in the species composition and decomposition of raised bog deposits and is chronologically linked to cultural changes and migrations at the Bronze Age/Iron Age transition. The temporary sharp rise of the atmospheric 14C content around 800 BC was caused by a sudden decline of solar activity. The solar wind declined, permitting more cosmic rays to penetrate into the atmosphere, and therefore the production of the cosmogenic isotope 14C increased. The climate shift was also recorded in Central and Eastern Europe, with rapid and total flooding of the Upper Volga region and a highstand of the Caspian Sea. In the Mississippi River basin, flooding frequencies greatly increased and there was an abrupt gap in the cultural transition from `Late Archaic' to `Early Woodland'. Paleoclimatological teleconnections point to a considerable role of solar UV in climate forcing. In the Central African rain forest belt and western India there was also a strong climate shift around 850 cal BC, but it was a shift to dryness (weakening of the summer monsoon). A possible palaeoclimatological explanation for the dry-wet transition in the temperate zones, and the contemporaneous wet-dry transition in the tropics (climatic teleconnections) will be given.

  2. Embryogenesis and tadpole description of Hyperolius castaneus Ahl, 1931 and H. jackie Dehling, 2012 (Anura, Hyperoliidae) from montane bog pools

    PubMed Central

    Lehr, Edgar; Dehling, J. Maximilian; Greenbaum, Eli; Sinsch, Ulrich

    2015-01-01

    Abstract Tadpoles of Hyperolius castaneus and Hyperolius jackie were found in the Nyungwe National Park in Rwanda and adjacent areas. Tadpoles of both species were identified by DNA-barcoding. At the shore of a bog pool three clutches of Hyperolius castaneus of apparently different age, all laid on moss pads (Polytrichum commune, Isotachis aubertii) or grass tussocks (Andropogon shirensis) 2–5 cm above the water level, were found. One clutch of Hyperolius castaneus was infested by larval dipterid flies. The most recently laid clutch contained about 20 eggs within a broad egg-jelly envelope. The eggs were attached to single blades of a tussock and distributed over a vertical distance of 8 cm. A pair of Hyperolius castaneus found in axillary amplexus was transported in a plastic container to the lab for observation. The pair deposited a total of 57 eggs (15 eggs attached to the upper wall of the transport container, 42 eggs floated in the water). Embryogenesis of the clutch was monitored in the plastic container at 20 ± 2 °C (air temperature) and documented by photos until Gosner Stage 25. The description of the tadpole of Hyperolius castaneus is based on a Gosner Stage 29 individual from a series of 57 tadpoles (Gosner stages 25–41). The description of the tadpole of Hyperolius jackie is based on a Gosner Stage 32 individual from a series of 43 tadpoles (Gosner stages 25–41). Egg laying behavior and embryogenesis are unknown for Hyperolius jackie. The labial tooth row formula for both species is 1/3(1) with a narrow median gap of the tooth row. Variation in external morphology was observed in size and labial tooth row formula within the species. With the tadpole descriptions of Hyperolius castaneus and Hyperolius jackie, 36 tadpoles of the 135 known Hyperolius species have been described, including five of the eleven Hyperolius species known from Rwanda. PMID:26798309

  3. Reconstructing the environmental impact of smelters using Pb isotope analyses of peat cores from bogs: Flin Flon, Manitoba and Harjavalta, Finland

    NASA Astrophysics Data System (ADS)

    Shotyk, W.

    2012-04-01

    provide a remarkably similar evolution of Pb isotopes, reaching values as low as 206Pb/207Pb = 1.151 (AD 1982) and 1.148 (AD 1984), respectively. At HAR, the minimum values are lower (206Pb/207Pb = 1.120) and earlier (AD 1954 -1967), presumably because of emissions from the smelter. The Pb concentrations in the porewaters from HAR are approximately an order of magnitude greater than the other sites, and the 206Pb/207Pb values significantly lower (ca. 1.12 vs. 1.15), because of the combined effects of greater Pb deposition and surface water acidification (pH 3.5 versus pH 4.0 in the other bogs).

  4. Spatial variation in rates of carbon and nitrogen accumulation in a boreal bog

    SciTech Connect

    Ohlson, M.; Oekland, R.H.

    1998-12-01

    Although previous studies hint at the occurrence of substantial spatial variation in the accumulation rates of C and N in bogs, the extent to which rates may vary on high-resolution spatial and temporal scales is not known. A main reason for the lack of knowledge is that it is problematic to determine the precise age of peat at a given depth. The authors determined rates of carbon and nitrogen accumulation in the uppermost decimeters of a bog ecosystem using the pine method, which enables accurate dating of surface peat layers. They combined accumulation data with numerical and geostatistical analyses of the recent vegetation to establish the relationship between bog vegetation and rate of peat accumulation. Use of a laser technique for spatial positioning of 151 age-determined peat cores within a 20 x 20 m plot made it possible to give the first tine-scaled account of spatial and temporal variation in rates of mass, carbon, and nitrogen accumulation during the last century. Rates of C and N accumulation were highly variable at all spatial scales studied. For example, after {approximately}125 yr of peat growth, C and N accumulation varied by factors of five and four, respectively, from 25 to 125 g/dm{sup 2} for C, and from 0.7 to 2.6 g/dm{sup 2} for N. It takes 40 yr of peat accumulation before significant amounts of C are lost through decay. Hummocks built up by Sphagnum fuscum and S. rubellum were able to maintain average rates of C accumulation that exceed 2 g{center_dot}dm{sup {minus}2}{center_dot} yr{sup {minus}1} during 50 yr of growth. The authors argue that data on spatial variation in rates of C accumulation are necessary to understand the role of boreal peatlands in the greenhouse effect and global climate.

  5. Temperature-induced increase in methane release from peat bogs: a mesocosm experiment.

    PubMed

    van Winden, Julia F; Reichart, Gert-Jan; McNamara, Niall P; Benthien, Albert; Damsté, Jaap S Sinninghe

    2012-01-01

    Peat bogs are primarily situated at mid to high latitudes and future climatic change projections indicate that these areas may become increasingly wetter and warmer. Methane emissions from peat bogs are reduced by symbiotic methane oxidizing bacteria (methanotrophs). Higher temperatures and increasing water levels will enhance methane production, but also methane oxidation. To unravel the temperature effect on methane and carbon cycling, a set of mesocosm experiments were executed, where intact peat cores containing actively growing Sphagnum were incubated at 5, 10, 15, 20, and 25°C. After two months of incubation, methane flux measurements indicated that, at increasing temperatures, methanotrophs are not able to fully compensate for the increasing methane production by methanogens. Net methane fluxes showed a strong temperature-dependence, with higher methane fluxes at higher temperatures. After removal of Sphagnum, methane fluxes were higher, increasing with increasing temperature. This indicates that the methanotrophs associated with Sphagnum plants play an important role in limiting the net methane flux from peat. Methanotrophs appear to consume almost all methane transported through diffusion between 5 and 15°C. Still, even though methane consumption increased with increasing temperature, the higher fluxes from the methane producing microbes could not be balanced by methanotrophic activity. The efficiency of the Sphagnum-methanotroph consortium as a filter for methane escape thus decreases with increasing temperature. Whereas 98% of the produced methane is retained at 5°C, this drops to approximately 50% at 25°C. This implies that warming at the mid to high latitudes may be enhanced through increased methane release from peat bogs.

  6. Radioactive deposits in California

    USGS Publications Warehouse

    Walker, George W.; Lovering, Tom G.

    1954-01-01

    containing rare earths. Secondary uranium minerals have been found as fracture coatings and as disseminations in various types of wall rock, although they are largely confined to areas of Tertiary volcanic rocks. Probably the uranium in the uraniferous deposits in California is related genetically to felsic crystalline rocks and felsic volcanic rocks; the present distribution of the secondary uranium minerals has been controlled, in part, by circulating ground waters and probably, in part, by magmatic waters related to the Tertiary volcanic activity. The thorium minerals are genetically related to the intrusion of pegmatite and plutonic crystalline rocks. None of the known deposits of radioactive minerals in California contain marketable reserves of uranium or thorium ore under economic conditions existing in 1952. With a favorable local market small lots of uranium ore may be available in the following places: the Rosamund prospect, the Rafferty and Chilson properties, the Lucky Star claim, and the Yerih group. The commercial production of thorium minerals will be possible, in the near future, only if these minerals can be recovered cheaply as a byproduct either from the mining of rare earths minerals at Mountain Pass or as a byproduct of placer mining for gold.

  7. Eddy covariance measurements of greenhouse gases from a restored and rewetted raised bog ecosystem.

    NASA Astrophysics Data System (ADS)

    Lee, S. C.; Christen, A.; Black, T. A.; Johnson, M. S.; Ketler, R.; Nesic, Z.; Merkens, M.

    2015-12-01

    Wetland ecosystems play a significant role in the global carbon (C) cycle. Wetlands act as a major long-term storage of carbon by sequestrating carbon-dioxide (CO2) from the atmosphere. Meanwhile, they can emit significant amounts of methane (CH4) due to anaerobic microbial decomposition. The Burns Bog Ecological Conservancy Area (BBECA) is recognized as one of Canada's largest undeveloped natural areas retained within an urban area. Historically, it has been substantially reduced in size and degraded by peat mining and agriculture. Since 2005, the bog has been declared a conservancy area, and the restoration efforts in BBECA focus on rewetting the disturbed ecosystems to promote a transition back to a raised bog. A pilot study measured CH4, CO2 and N2O exchanges in 2014 and concluded to monitor CO2, CH4 fluxes continuously. From the perspective of greenhouse gas (GHG) emissions, CO2 sequestered in bog needs to be protected and additional CO2 and CH4 emissions due to land-cover change need to be reduced by wise management. In this study, we measured the growing-season (June-September) fluxes of CO2 and CH4 exchange using eddy covariance (EC). A floating platform with an EC system for both CO2 (closed-path) and CH4 (open-path) began operation in June 2015. During the growing-season, gross ecosystem photosynthesis (GEP) and ecosystem respiration (Re) averaged 5.87 g C m-2 day-1 and 2.02 g C m-2 day-1, respectively. The magnitude of GEP and Re were lower than in previous studies of pristine northern peatlands. The daily average CH4 emission was 0.99 (±1.14) g C m-2 day-1 and it was higher than in most previous studies. We also characterized how environmental factors affected the seasonal dynamics of these exchanges in this disturbed peatland. Our measurements showed that soil temperature and soil water content were major drivers of seasonal changes of GHG fluxes. The daily average GHG warming potential (GWP) of the emissions in the growing seasons (from CO2 and CH4

  8. Unexpected DNA-fingerprinting pattern in a deep peat bog: evidence for methanotrophs at the bottom?

    NASA Astrophysics Data System (ADS)

    Steinmann, P.; Rossi, P.; Huon, S.; Eilrich, B.; Casati, S.

    2003-04-01

    With the goal of a better understanding of the fate of methane in the deep layers of peat bogs, we analysed the microbial 16S rDNA gene pool and measured the stable carbon isotope composition of bulk peat of a deep (6 m) peat bog profile (Etang de la Gruyère, Switzerland). Both Bacterial and Archaean communities were assessed using respectively TTGE (Temporal Temperature Gradient Electrophoresis) and SSCP (Single Strand Conformation Polymorphism), with fragments of the V1-V3 region of the 16S rDNA gene. The "relative diversity" shown in the TTGE AND SSCP gel patterns is presented using indices and band numbers per sample (Simpson evenness). PCA was calculated on the basis of the intensities of all bands found in the TTGE and SSCP fingerprinting profiles. These DNA fingerprinting patterns reveal the presence of a structured microbial community throughout the whole depth profile. Clear differences can be observed between the communities found in the near surface layers and those found at depth. Surprisingly, for both Archaean and Bacterial communities, the deepest samples display a high similarity level with those found in the first 20 centimeters. The δ13C values of the peat are relatively constant from the surface of the bog down to a depth of 5 m (values between 25.5 ppm and 26.5 ppm). Below 5 m the values decrease considerably with depth ( 28.5 ppm). As a working hypothesis to explain the two observations, we consider the possibility of the presence of methanotrophs in the deepest parts of the bogs. The electron acceptors needed for methane oxidation could be derived from lateral advection of less reducing groundwater. However, available pore water analyses suggest that neither molecular oxygen, nor sulfate or nitrate are present. One possible oxidising agent would be trivalent iron (solid or colloidal). Indeed are the iron concentrations in the deeper pore waters are elevated. Such deep methanotrophic microbial community could be similar to those found near

  9. Preliminary stable isotope results from the Mohos peat bog, East-Carpathians

    NASA Astrophysics Data System (ADS)

    Túri, Marianna; Palcsu, László; Futó, István; Hubay, Katalin; Molnár, Mihály; Rinyu, László; Braun, Mihály

    2016-04-01

    This work provides preliminary results of an isotope investigation carried out on a peat core drilled in the ombrotrophic Mohos peat bog, Ciomadul Mountain, (46°8'3.60"N, 25°54'19.43"E, 1050 m.a.s.l.), East Carpathians, Romania. The Ciomadul is a single dacitic volcano with two craters: the younger Saint Ana and the older Mohos which is a peat bog, and surrounded by a number of individual lava domes as well as a narrow volcaniclastic ring plain volcano. A 10 m long peat core has been taken previously, and is available for stable oxygen and carbon isotope analysis. It is known from our previous work (Hubay et al., 2015) that it covers a period from 11.500 cal year B.P. to present. The peat bog is composed mainly of Sphagnum, which has a direct relationship with the environment, making it suitable for examine the changes in the surrounding circumstances. Isotopic analysis of the prepared cellulose from Sphagnum moss has the attribute to provide such high resolution quantitative estimates of the past climate and there is no such climate studies in this area where the past climate investigations based on oxygen isotope analysis of the Sphagnum. Oxygen and carbon stable isotope analysis were carried out on the hemicellulose samples, which were chemically prepared for 14C dating and taken from every 30 cm of the 10 m long peat core. The oxygen isotope composition of the precipitation can be revealed from the δ18O values of the prepared cellulose samples, since, while carbon isotope ratio tells more about the wet and dry periods of the past. Studying both oxygen and carbon isotope signatures, slight fluctuations can be seen during the Holocene like some of the six periods of significant climate changes can be seen in this resolution during the time periods of 9000-8000, 6000-5000, 4200-3800, 3500-2500, 1200-1000, and 600-150 cal yr B.P. Additionally, the late Pleistocene - early Holocene environmental changes can be clearly observed as Pleistocene peat samples have

  10. Impact of environmental factors on dissolved organic carbon concentrations in German bogs under grassland

    NASA Astrophysics Data System (ADS)

    Frank, Stefan; Tiemeyer, Bärbel; Freibauer, Annette

    2013-04-01

    Peatlands cover about 5% of Germany's land area. Agricultural use combined with drainage increases the greenhouse gas emissions and alters the dissolved organic carbon (DOC) concentrations in the soil- and groundwater of these ecosystems. Cycling of DOC is influenced by a complex interaction of environmental factors such as peat characteristics, groundwater level, meteorological conditions, pH-value and ionic strength. Reasons for elevated DOC concentrations are debated in literature, but only a few studies on the dynamic of DOC in raised bogs in Germany have been conducted so far. In Germany, raised bogs are mainly used as grassland. Therefore, five grassland study sites and one natural reference have been selected. The bog "Ahlenmoor" has a deep, medium to weakly decomposed peat layer. There, three study sites represent different land use intensities with a corresponding groundwater table (intensive grassland, extensive grassland, natural reference). The bog relict "Großes Moor" is characterised by a shallow amorphous peat layer, which is partly mixed with sand. There, three sites in an extensive grassland were chosen to study the effects of soil carbon concentrations (9 to 48 %) and groundwater levels. At each site, nine suction plates (three replicates in each depth) and three tensiometers were installed in 15, 30 and 60 cm. Soil water was sampled fortnightly from June 2011 to December 2012 and analysed for electrical conductivity, pH-value and DOC concentration. Compared to most literature values, DOC concentrations at our study sites were very high (on average, 197 to 55 mg/L). At the "Ahlenmoor", an increase in agricultural intensity and a lower groundwater table increases both the DOC concentrations and their variability in the soil water in order intensive grassland > extensive grassland > natural site. Surprisingly, soil carbon concentration and groundwater table gradients as investigated in the "Großes Moor" did only lead to minor differences in the

  11. 137Cs in fungal sporocarps in relation to vegetation in a bog, pine swamp and forest along a transect.

    PubMed

    Vinichuk, M; Rosén, K; Dahlberg, A

    2013-01-01

    In this study, we estimated the relative importance of vegetation and fungi for radiocesium uptake and biological retention in adjacent bog, pine swamp, and forest. The measurements for (137)Cs activity concentration in sporocarps (i.e. fruitbodies of fungi) and vegetation along a bog to forest transect were combined with complementary published data to calculate estimates. Aboveground vegetation comprised 17.7% of the total fallout-derived radiocesium in the system in bog, 16.5% in pine swamp, and 40.6% in forest. In fungal sporocarps grown along a gradient, (137)Cs activity comprised <0.001% of the total radiocesium for peat bog, <0.02% for pine swamp, and 0.11% for forest. Total (137)Cs activity in sporocarps increased along the gradient due to increased production of sporocarps in the presence of trees from 0.006 (bog), 0.097 (pine swamp) and 0.67 (forest) g dwt m(-2). Based on calculation of the total vegetation biomass and through relationships between fungal biomass in sporocarps and as mycelia in soil, the total (137)Cs activity located in fungi was estimated as 0.1% in bog, 2% in pine swamp, and 11% in forest. An analysis of the time-dependency of (137)Cs in the sporocarps in forest between 1990 and 2011 suggested an ecological half-life for (137)Cs between 8 and 13 years. Although fungi comprised a relatively small fraction of the total radiocesium in the systems, its activity decreased slowly with time, and ecological residence time for (137)Cs in sporocarps of fungi was long, suggesting they will continue to contribute to the accumulation and cycling of this radionuclide in forest.

  12. The impact of peat harvesting and natural regeneration on the water balance of an abandoned cutover bog, Quebec

    NASA Astrophysics Data System (ADS)

    van Seters, Tim E.; Price, Jonathan S.

    2001-02-01

    Harvested sites rarely return to functional ecosystems after abandonment because drainage and peat extraction lower the water table and expose relatively decomposed peat, which is hydrologically unsuitable for Sphagnum moss re-establishment. Some natural regeneration of Sphagnum has occurred in isolated pockets on traditionally harvested (block-cut) sites, for reasons that are poorly understood, but are related to natural functions that regulate runoff and evaporation. This study evaluates the water balance of a naturally regenerated cutover bog and compares it with a nearby natural bog of similar size and origin, near Riviere du Loup, Quebec. Water balance results indicated that evapotranspiration was the major water loss from the harvested bog, comprising 92 and 84% of total outputs (2·9 mm day-1) during the 1997 and 1998 seasons, respectively. Despite denser tree cover at the harvested site, evapotranspiration from the natural bog was similar, although less spatially variable. At the harvested site, evaporative losses ranged from 1·9 mm day-1 on raised baulks and roads to 3·6 mm day-1 from moist surfaces with Sphagnum. Although about half of the ditches were inactive or operating at only a fraction of their original efficiency, runoff was still significant at 12 and 24% of precipitation during the 1997 and 1998 study seasons, respectively. This compares with negligible rates of runoff at the natural bog. Thus the cutover bog, although abandoned over 25 years ago, has not regained its hydrological function. This is both a cause and effect of its inability to support renewed Sphagnum regeneration. Without suitable management (e.g. blocking ditches), this site is not likely to improve for a very long time.

  13. High-resolution Record of Holocene Climate, Vegetation, and Fire from a Raised Peat Bog, Prince Edward Island, Canadian Maritimes

    NASA Astrophysics Data System (ADS)

    Peros, M. C.; Chan, K.; Ponsford, L.; Carroll, J.; Magnan, G.

    2014-12-01

    Raised peat bogs receive all precipitation and nutrients from the atmosphere and are thus widely used archives for information on past environments and climates. In this paper we provide high-resolution multi-proxy data from a raised bog from northeastern Prince Edward Island, located in the Gulf of St. Lawrence, Canada. We studied testate amoeba (a proxy for water table depth), macrocharcoal (a proxy for local-scale fire), peat humification (a proxy for decomposition), plant macrofossils (indicative of local-scale vegetation), and organic matter content (yielding carbon accumulation rates) from a 5.5 m long core lifted from the center of Baltic Bog. Eleven AMS radiocarbon dates show that peat accumulation began before 9000 cal yr BP and continued almost uninterrupted until the present. The macrofossil data show that a transition from a sedge-dominated fen to a sphagnum-dominated bog occurred around 8000 cal yr BP, and sphagnum remained dominant in the bog throughout most of the Holocene. A testate amoeba-based reconstruction of water table depth indicates that conditions were drier during the early Holocene (~8000 to 5000 cal yr BP) and became gradually wetter into the late Holocene. In addition, a number of higher frequency shifts in precipitation are inferred throughout the Holocene on the basis of the testate amoeba and humification results. The macrocharcoal evidence indicates fire—probably in the surrounding forest—was relatively more common during the early Holocene, perhaps due to drier climate conditions. A large influx of charcoal at around 2000 cal yr BP suggests the presence of one or more major fires at this time, and a concurrent decrease in the rate of peat accumulation indicates the fire may have affected the bog itself. The data from Baltic Bog is broadly comparable to other proxy data (in particular pollen studies) from the Canadian Maritimes. This work is important because it: 1) helps us better understand the role of hydroclimatic

  14. Holocene monsoon variability inferred from Targo Xian peat bog in the Tangra Yumco basin, central Tibetan Plateau

    NASA Astrophysics Data System (ADS)

    Henkel, Karoline; Haberzettl, Torsten; Miehe, Sabine; Frenzel, Peter; Daut, Gerhard; Dietze, Elisabeth; Kasper, Thomas; Ahlborn, Marieke; Mäusbacher, Roland

    2013-04-01

    The Tibetan Plateau is the greatest plateau on Earth with an average altitude of 4,500 m asl. Due to its high elevation, large area and significant role in the formation of the Asian Monsoon Systems (e.g., Indian Ocean and East-Asian Summer Monsoon) it is considered to react very sensitive to climate variations. The numerous lake systems on the Tibetan Plateau represent excellent archives reflecting variations in the strength of the monsoon system in terms of hydrological changes expressed in lake level fluctuations. For example, terraces and lacustrine deposits around the saline lake Tangra Yumco indicate lake level highstands up to ~215 m higher than the present lake level. To study Holocene lake level variations we investigated a 3.6 m long sediment core recovered from a peat bog (near the Targo Xian settlement, 30°46'N, 86°40'E) on a recessional lake level terrace ~150 m above the present shoreline of Tangra Yumco. In particular, our analyses of sedimentological (grain size), geochemical (CNS and ICP-OES) and mineralogical (XRD) data allow a detailed and high-resolution interpretation of the hydrological conditions during the Holocene. The existence of two carbonate layers in the Targo Xian record, separated by a sand layer and intercalated in peat sequences at the bottom and top of the core, provide evidence for two stable lake stages at the coring position. Peat at the bottom of the core, which is radiocarbon-dated to 11,130 +130/-345 cal BP, indicates wetland conditions similar to the Recent situation (Miehe et al., submitted). After a transition zone, a layer of pure aragonitic lake marl gives evidence for a lake stage. During this stage, high values of the total inorganic carbon (TIC) and Ca/Ti ratios as well as low C/N ratios point to a stable lake due to wet climatic conditions. This carbonate layer can be correlated with a 2-3 m thick carbonate layer found in outcrops around the present lake Tangra Yumco presenting a high lake level until approx. 2

  15. Stable (206Pb, 207Pb, 208Pb) and radioactive (210Pb) lead isotopes in 1 year of growth of Sphagnum moss from four ombrotrophic bogs in southern Germany: Geochemical significance and environmental implications

    NASA Astrophysics Data System (ADS)

    Shotyk, William; Kempter, Heike; Krachler, Michael; Zaccone, Claudio

    2015-08-01

    The surfaces of Sphagnum carpets were marked with plastic mesh and 1 year later the production of plant matter was harvested in four ombrotrophic bogs from two regions of southern Germany: Upper Bavaria (Oberbayern, OB) and the Northern Black Forest (Nordschwarzwald, NBF). Radioactive, 210Pb was determined in solid samples using ultralow background gamma spectrometry while total Pb concentrations and stable isotopes (206Pb, 207Pb, 208Pb) were determined in acid digests using ICP-SMS. Up to 12 samples (40 × 40 cm) were collected per site, and 6-10 sites investigated per bog. The greatest variations within a given sampling site were in the range 212-532 Bq kg-1 for 210Pb activity, whereas 206Pb/207Pb and 208Pb/206Pb varied less than 1%. The median values of all parameters for the sites (6-10 per bog) were not significantly different. The median activities of 210Pb (Bq kg-1) in the mosses collected from the bogs in NBF (HO = 372 ± 56, n = 55; WI = 342 ± 58, n = 93) were slightly less from those in OB (GS = 394 ± 50, n = 55; KL = 425 ± 58, n = 24). However, the mosses in the NBF bogs exhibited much greater productivity (187-202 g m-2 a-1) compared to those of OB (71-91 g m-2 a-1), and this has a profound impact on the accumulation rates of 210Pb (Bq m-2 a-1), with the bogs in the NBF yielding fluxes (HO = 73 ± 30; WI = 65 ± 20) which are twice those of OB (GS = 29 ± 11; KL = 40 ± 13). Using the air concentrations of 210Pb measured at Schauinsland (SIL) in the southern Black Forest and average annual precipitation, the atmospheric fluxes of 210Pb at SIL (340 Bq m-2 a-1) exceeds the corresponding values obtained from the mosses by a factor of five, providing the first quantitative estimate of the net retention efficiency of 210Pb by Sphagnum. When the 210Pb activities of all moss samples are combined (n = 227), a significant decrease with increasing plant production rate is observed; in contrast, total Pb concentrations show the opposite trend. The contrasting

  16. Nitrogen deposition does not enhance Sphagnum decomposition.

    PubMed

    Manninen, S; Kivimäki, S; Leith, I D; Leeson, S R; Sheppard, L J

    2016-11-15

    Long-term additions of nitrogen (N) to peatlands have altered bryophyte growth, species dominance, N content in peat and peat water, and often resulted in enhanced Sphagnum decomposition rate. However, these results have mainly been derived from experiments in which N was applied as ammonium nitrate (NH4NO3), neglecting the fact that in polluted areas, wet deposition may be dominated either by NO3(-) or NH4(+). We studied effects of elevated wet deposition of NO3(-) vs. NH4(+) alone (8 or 56kgNha(-1)yr(-1) over and above the background of 8kgNha(-1)yr(-1) for 5 to 11years) or combined with phosphorus (P) and potassium (K) on Sphagnum quality for decomposers, mass loss, and associated changes in hummock pore water in an ombrotrophic bog (Whim). Adding N, especially as NH4(+), increased N concentration in Sphagnum, but did not enhance mass loss from Sphagnum. Mass loss seemed to depend mainly on moss species and climatic factors. Only high applications of N affected hummock pore water chemistry, which varied considerably over time. Overall, C and N cycling in this N treated bog appeared to be decoupled. We conclude that moss species, seasonal and annual variation in climatic factors, direct negative effects of N (NH4(+) toxicity) on Sphagnum production, and indirect effects (increase in pH and changes in plant species dominance under elevated NO3(-) alone and with PK) drive Sphagnum decomposition and hummock C and N dynamics at Whim. PMID:27487447

  17. Carbon Balance and Greenhouse Gas Fluxes in a Thermokarst Bog in Interior Alaska: Positive and Negative Feedbacks from Permafrost Thaw

    NASA Astrophysics Data System (ADS)

    Waldrop, M. P.; McFarland, J.; Euskirchen, E. S.; Turetsky, M. R.; Harden, J. W.; Manies, K.; Jones, M.; McGuire, A. D.

    2012-12-01

    Climate change in northern latitudes is expected to cause widespread permafrost thaw in Interior Alaska over the 21st century. One result of permafrost thaw is land subsidence and the formation of thermokarst bogs. The net result of permafrost thaw on carbon (C) balance depends on the difference between forest floor carbon loss and Sphagnum productivity in the bog. However, greenhouse gas feedbacks including methane (CH4) and nitrous oxide (N2O) can be significant from a thawed saturated permafrost environment, strongly modifying the net climate forcing caused by CO2 exchange. We hypothesized that the saturated conditions in thermokarst bogs would decrease respiration compared to an intact permafrost forest, potentially promoting net CO2 uptake. However, CH4 and N2O production in the thermokarst bog may reduce any potential negative climate feedback. Our field sites are located at the Alaska Peatland Experiment (APEX), part of the Bonanza Creek LTER outside Fairbanks, Alaska. We examined net changes in C storage, greenhouse gas fluxes, and soil nutrients in a lowland black spruce forest with intact permafrost and an adjacent young thermokarst bog that developed 20-40 years ago. Using combined flux towers and autochambers (0.36 m2), we quantified net ecosystem exchange (NEE), ecosystem respiration (ER), and gross primary productivity (GPP). We also quantified semi-continuous CH4 fluxes using an isotopic CH4 analyzer (Picarro Inc) connected in-line to the autochambers, and N2O was measured using static chambers. Chamber measurements suggest that in mid-summer of 2012 the thermokarst bog was a net sink of CO2, while the understory black spruce was a net source. Furthermore, preliminary chamber measurements from 2012 indicate that thermokarst conditions have decreased respiration compared to the black spruce forest, potentially promoting net CO2 uptake in the bog. However, eddy covariance measurements of CO2 in 2011 indicate that the thermokarst bog was a source of CO2

  18. Multi-omics of permafrost, active layer and thermokarst bog soil microbiomes.

    PubMed

    Hultman, Jenni; Waldrop, Mark P; Mackelprang, Rachel; David, Maude M; McFarland, Jack; Blazewicz, Steven J; Harden, Jennifer; Turetsky, Merritt R; McGuire, A David; Shah, Manesh B; VerBerkmoes, Nathan C; Lee, Lang Ho; Mavrommatis, Kostas; Jansson, Janet K

    2015-05-14

    Over 20% of Earth's terrestrial surface is underlain by permafrost with vast stores of carbon that, once thawed, may represent the largest future transfer of carbon from the biosphere to the atmosphere. This process is largely dependent on microbial responses, but we know little about microbial activity in intact, let alone in thawing, permafrost. Molecular approaches have recently revealed the identities and functional gene composition of microorganisms in some permafrost soils and a rapid shift in functional gene composition during short-term thaw experiments. However, the fate of permafrost carbon depends on climatic, hydrological and microbial responses to thaw at decadal scales. Here we use the combination of several molecular 'omics' approaches to determine the phylogenetic composition of the microbial communities, including several draft genomes of novel species, their functional potential and activity in soils representing different states of thaw: intact permafrost, seasonally thawed active layer and thermokarst bog. The multi-omics strategy reveals a good correlation of process rates to omics data for dominant processes, such as methanogenesis in the bog, as well as novel survival strategies for potentially active microbes in permafrost. PMID:25739499

  19. Multi-omics of permafrost, active layer and thermokarst bog soil microbiomes

    NASA Astrophysics Data System (ADS)

    Hultman, Jenni; Waldrop, Mark P.; Mackelprang, Rachel; David, Maude M.; McFarland, Jack; Blazewicz, Steven J.; Harden, Jennifer; Turetsky, Merritt R.; McGuire, A. David; Shah, Manesh B.; Verberkmoes, Nathan C.; Lee, Lang Ho; Mavrommatis, Kostas; Jansson, Janet K.

    2015-05-01

    Over 20% of Earth's terrestrial surface is underlain by permafrost with vast stores of carbon that, once thawed, may represent the largest future transfer of carbon from the biosphere to the atmosphere. This process is largely dependent on microbial responses, but we know little about microbial activity in intact, let alone in thawing, permafrost. Molecular approaches have recently revealed the identities and functional gene composition of microorganisms in some permafrost soils and a rapid shift in functional gene composition during short-term thaw experiments. However, the fate of permafrost carbon depends on climatic, hydrological and microbial responses to thaw at decadal scales. Here we use the combination of several molecular `omics' approaches to determine the phylogenetic composition of the microbial communities, including several draft genomes of novel species, their functional potential and activity in soils representing different states of thaw: intact permafrost, seasonally thawed active layer and thermokarst bog. The multi-omics strategy reveals a good correlation of process rates to omics data for dominant processes, such as methanogenesis in the bog, as well as novel survival strategies for potentially active microbes in permafrost.

  20. Mapping raised bogs with an iterative one-class classification approach

    NASA Astrophysics Data System (ADS)

    Mack, Benjamin; Roscher, Ribana; Stenzel, Stefanie; Feilhauer, Hannes; Schmidtlein, Sebastian; Waske, Björn

    2016-10-01

    Land use and land cover maps are one of the most commonly used remote sensing products. In many applications the user only requires a map of one particular class of interest, e.g. a specific vegetation type or an invasive species. One-class classifiers are appealing alternatives to common supervised classifiers because they can be trained with labeled training data of the class of interest only. However, training an accurate one-class classification (OCC) model is challenging, particularly when facing a large image, a small class and few training samples. To tackle these problems we propose an iterative OCC approach. The presented approach uses a biased Support Vector Machine as core classifier. In an iterative pre-classification step a large part of the pixels not belonging to the class of interest is classified. The remaining data is classified by a final classifier with a novel model and threshold selection approach. The specific objective of our study is the classification of raised bogs in a study site in southeast Germany, using multi-seasonal RapidEye data and a small number of training sample. Results demonstrate that the iterative OCC outperforms other state of the art one-class classifiers and approaches for model selection. The study highlights the potential of the proposed approach for an efficient and improved mapping of small classes such as raised bogs. Overall the proposed approach constitutes a feasible approach and useful modification of a regular one-class classifier.

  1. Mictomys borealis (northern bog lemming) and the Wisconsin paleoecology of the east-central Great Basin

    NASA Astrophysics Data System (ADS)

    Mead, Jim I.; Bell, Christopher J.; Murray, Lyndon K.

    1992-03-01

    Teeth of northern bog lemming, Mictomys borealis, are reported from Cathedral and Smith Creek caves and represent the first Wisconsin remains of the genus from the Great Basin. Specimens from Cathedral Cave, Snake Range, are associated with U-series ages of 24,000 to 15,000 yr B.P. Previous work with pollen and packrat middens, dating to the same age as the Mictomys, indicate that Smith Creek Canyon contained a riparian, locally mesic community, including Picea engelmannii (spruce), Betula sp. (birch), Cercocarpus sp. (mountain mahogany), and Artemisia sp. (sagebrush) among other species. Exposed canyon slopes and the adjacent valley apparently contained a more xeric steppe community including sagebrush and Chenopodiineae species; rocky outcrop permitted Pinus flexilis (limber pine) and P. longaeva (bristlecone pine) to grow adjacent to Lake Bonneville or low in the canyon. The region apparently experienced a dry climate (not necessarily drier than today); however, Smith Creek Canyon was fed by glacial meltwater from Mt. Moriah. The northern bog lemming probably lived only in the riparian community and possibly on the north-facing slope below Cathedral Cave. Few canyons of the Snake Range would have had the unusually mesic conditions found in Smith Creek Canyon.

  2. Heat transport in the Red Lake Bog, Glacial Lake Agassiz Peatlands

    USGS Publications Warehouse

    McKenzie, J.M.; Siegel, D.I.; Rosenberry, D.O.; Glaser, P.H.; Voss, C.I.

    2007-01-01

    We report the results of an investigation on the processes controlling heat transport in peat under a large bog in the Glacial Lake Agassiz Peatlands. For 2 years, starting in July 1998, we recorded temperature at 12 depth intervals from 0 to 400 cm within a vertical peat profile at the crest of the bog at sub-daily intervals. We also recorded air temperature 1 m above the peat surface. We calculate a peat thermal conductivity of 0.5 W m-1 ??C-1 and model vertical heat transport through the peat using the SUTRA model. The model was calibrated to the first year of data, and then evaluated against the second year of collected heat data. The model results suggest that advective pore-water flow is not necessary to transport heat within the peat profile and most of the heat is transferred by thermal conduction alone in these waterlogged soils. In the spring season, a zero-curtain effect controls the transport of heat through shallow depths of the peat. Changes in local climate and the resulting changes in thermal transport still may cause non-linear feedbacks in methane emissions related to the generation of methane deeper within the peat profile as regional temperatures increase. Copyright ?? 2006 John Wiley & Sons, Ltd.

  3. Multi-omics of Permafrost, Active Layer and Thermokarst Bog Soil Microbiomes

    SciTech Connect

    Hultman, Jenni; Waldrop, Mark P.; Mackelprang, Rachel; David, Maude; McFarland, Jack; Blazewicz, Steven J.; Harden, Jennifer W.; Turetsky, Merritt; McGuire, A. David; Shah, Manesh B.; VerBerkmoes, Nathan C.; Lee, Lang Ho; Mavrommatis, Konstantinos; Jansson, Janet K.

    2015-03-04

    Over 20% of Earth’s terrestrial surface is underlain by permafrost with vast stores of carbon that, if thawed may represent the largest future transfer of C from the biosphere to the atmosphere 1. This process is largely dependent on microbial responses, but we know little about microbial activity in intact, let alone in thawing permafrost. Molecular approaches have recently revealed the identities and functional gene composition of microorganisms in some permafrost soils 2-4 and a rapid shift in functional gene composition during short-term thaw experiments 3. However, the fate of permafrost C depends on climatic, hydrologic, and microbial responses to thaw at decadal scales 5, 6. Here the combination of several molecular “omics” approaches enabled us to determine the phylogenetic composition of the microbial community, including several draft genomes of novel species, their functional potential and activity in soils representing different states of thaw: intact permafrost, seasonally thawed active layer and thermokarst bog. The multi-omics strategy revealed a good correlation of process rates to omics data for dominant processes, such as methanogenesis in the bog, as well as novel survival strategies for potentially active microbes in permafrost.

  4. Multi-omics of permafrost, active layer and thermokarst bog soil microbiomes.

    PubMed

    Hultman, Jenni; Waldrop, Mark P; Mackelprang, Rachel; David, Maude M; McFarland, Jack; Blazewicz, Steven J; Harden, Jennifer; Turetsky, Merritt R; McGuire, A David; Shah, Manesh B; VerBerkmoes, Nathan C; Lee, Lang Ho; Mavrommatis, Kostas; Jansson, Janet K

    2015-05-14

    Over 20% of Earth's terrestrial surface is underlain by permafrost with vast stores of carbon that, once thawed, may represent the largest future transfer of carbon from the biosphere to the atmosphere. This process is largely dependent on microbial responses, but we know little about microbial activity in intact, let alone in thawing, permafrost. Molecular approaches have recently revealed the identities and functional gene composition of microorganisms in some permafrost soils and a rapid shift in functional gene composition during short-term thaw experiments. However, the fate of permafrost carbon depends on climatic, hydrological and microbial responses to thaw at decadal scales. Here we use the combination of several molecular 'omics' approaches to determine the phylogenetic composition of the microbial communities, including several draft genomes of novel species, their functional potential and activity in soils representing different states of thaw: intact permafrost, seasonally thawed active layer and thermokarst bog. The multi-omics strategy reveals a good correlation of process rates to omics data for dominant processes, such as methanogenesis in the bog, as well as novel survival strategies for potentially active microbes in permafrost.

  5. Paleodrainage-unconformity model as guide to uranium deposits

    SciTech Connect

    Seeland, D.

    1984-04-01

    This paper considers a uranium occurrence model that shows how early Eocene and Oligocene depositional patterns and paleography can be used to identify favorable host rocks and to suggest where uraniferous ground water passed through these rocks. The uranium in the ground water was derived mostly from volcanic ash of the Oligocene White River Group. This model accounts for most known uranium deposits and occurrences in eastern Wyoming, western South Dakota, and western Nebraska. All major deposits in Eocene sandstones are in rocks of the fan-channel facies that were identified by sand grain size and shape studies, and most deposits are basinward of present-day major mountain valleys. Deposits occur only where rocks of this facies are less than 300 m (980 ft) below the reconstructed basal Oligocene surface, a distance calculated from roll-front migration and erosion rates. Uranium deposits in other than Eocene rocks also are related to the configuration of the pre-Oligocene surface. White River channel sandstones have deposits and occurrences along a 200-km (125-mi) section of a major Oligocene river in eastern Wyoming and Nebraska. Oligocene trans-mountain drainages localized uranium occurrences in Precambrian granitic rocks in the Laramie Mountains. Deposits in Cretaceous rocks in northern Colorado and along the flanks of the Black Hills lie beneath the axes of Oligocene channels. The channels were the major conduits that localized the movement of the uranium-bearing solutions. Rocks underlying the divides between the channels are unfavorable for uranium deposits where the channels are parallel to the regional dip, because the divides have a thick impervious lateritic soil cover.

  6. Trench Logs and Scarp Data from an Investigation of the Steens Fault Zone, Bog Hot Valley and Pueblo Valley, Humboldt County, Nevada

    USGS Publications Warehouse

    Personius, Stephen F.; Crone, Anthony J.; Machette, Michael N.; Kyung, Jai Bok; Cisneros, Hector; Lidke, David J.; Mahan, Shannon

    2006-01-01

    Introduction: This report contains field and laboratory data from a study of the Steens fault zone near Denio, Nev. The 200-km-long Steens fault zone forms the longest, most topographically prominent fault-bounded escarpment in the Basin and Range of southern Oregon and northern Nevada. The down-to-the-east normal fault is marked by Holocene fault scarps along nearly half its length, including the southern one-third of the fault from the vicinity of Pueblo Mountain in southern Oregon to the southern margin of Bog Hot Valley (BHV) southwest of Denio, Nev. We studied this section of the fault to better constrain late Quaternary slip rates, which we hope to compare to deformation rates derived from a recently established geodetic network in the region (Hammond and Thatcher, 2005). We excavated a trench in May 2003 across one of a series of right-stepping fault scarps that extend south from the southern end of the Pueblo Mountains and traverse the floor of Bog Hot Valley, about 4 km south of Nevada State Highway 140. This site was chosen because of the presence of well-preserved fault scarps, their development on lacustrine deposits thought to be suitable for luminescence dating, and the proximity of two geodetic stations that straddle the fault zone. We excavated a second trench in the southern BHV, but the fault zone in this trench collapsed during excavation and thus no information about fault history was documented from this site. We also excavated a soil pit on a lacustrine barrier bar in the southern Pueblo Valley (PV) to better constrain the age of lacustrine deposits exposed in the trench. The purpose of this report is to present photomosaics and trench logs, scarp profiles and slip data, soils data, luminescence and radiocarbon ages, and unit descriptions obtained during this investigation. We do not attempt to use the data presented herein to construct a paleoseismic history of this part of the Steens fault zone; that history will be the subject of a future

  7. Development of a high resolution modeling tool for prediction of waterflows through complex mires: Example of the Mukhrino bog complex in West Siberian middle Taiga Zone

    NASA Astrophysics Data System (ADS)

    Zarov, Evgeny A.; Schmitz, Oliver; Bleuten, Wladimir

    2015-04-01

    Water flow through peat bogs differ substantially from mineral soil landscapes. Permeability of the peatlayers decrease dramatically with depth within the permanently watersaturated peat layers (Catotelm), whereas the 10-60 cm thick superficial layer (Acrotelm) has a very high conductivity. Water flows predominantly in this acrotelm layer where an open structure of stems of mosses and few plants hardly limit water flow. By omitting this superficial flow infrastructures in many places block the waterflow. Moreover, the different bog types within a complex bog have different hydrological conductivities. Without considering the typical water-flow of bogs the construction of roads and platforms for oil and gas production threatens downhill mire ecosystems by partly drainage. The objective of our study was to develop a modeling tool which can be used to predict quantitatively spatially distributed water-flow of a bog complex. A part of the extensive bog complex "Mukhrino bog complex" located at the left bank of Irtysh river near the West Siberian town Khanty-Mansiysk' was chosen as modeling area. Water discharge from this bog catchment occurs by "waterfalls" at the East margin where a scarp with ca. 8 m elevation difference has been developed by backward erosion into the bog by the Mukhrino river. From field observations it was proven that no discharge of groundwater occurred at the margin of the bog catchment area. We used PCRaster-MODFLOW as modeling environment. The model area size was 3.8 km2, cell size 5 m and the model included 3 Acrotelm layers and 3 Catotelm layers. Thickness of Acrotelm and Catotelm have been measured by coring in transects. Input data of rain, snow have been recorded in the study area. Evapotranspiration was measured with small lysimeters and crop factors for different land unit types (open water, raised bog, patterned bog, poor fens) were elaborated by water balance modeling (1-D). Land unit types have been mapped by supervised classification

  8. Carbon and Nitrogen Isotope Variation in Peat Bogs in the Midwestern US: Implications for Holocene Climate Reconstruction

    NASA Astrophysics Data System (ADS)

    Wong, D.; Paytan, A.; Jackson, S.

    2008-12-01

    A peat core, from near the center of Minden Bog in Michigan, representing about 3500 years of accumulation was previously analyzed for plant macrofossils, colorimetric humification, and testate amoebae to yield three independent climate proxies (Booth and Jackson, 2003). The plant macrofossil data show the site to be sensitive to bog water table fluctuations. The data suggest that this may be related to regional climatic changes. We analyzed the carbon and nitrogen isotopes, as well as the carbon-nitrogen ratios in the bulk peat samples to determine if fluctuations of these records correspond to climate events as seen in the plant microfossil and amoebae records. The degree to which peat-based carbon and nitrogen isotope records reflect changes in the relative distribution of vegetation and, in turn, reflect temperature changes in effective precipitation (precipitation minus evapotranspiration) will be assessed. Peat carbon and nitrogen isotope records will be compared with existing proxy climate records and with a temperature reconstruction based on testate amoebae in bogs. We expect that climate-related changes, in the relative abundance of vegetation remains accumulating in the peat bogs, will be recorded in the organic matter in forms of carbon and nitrogen isotopes.

  9. Influence of selected environmental factors on the abundance of aerobic anoxygenic phototrophs in peat-bog lakes.

    PubMed

    Lew, Sylwia; Lew, Marcin; Koblížek, Michal

    2016-07-01

    Aerobic anoxygenic phototrophs (AAPs) are photoheterotrophic prokaryotes that are widespread in many limnic and marine environments. So far, little is known about their distribution in peat-bog lakes. Seventeen peat-bog lakes were sampled during three summer seasons 2009, 2011, and 2012, and the vertical distribution of AAPs was determined by infrared epifluorescence microscopy. The analysis demonstrated that in the surface layers of the studied lakes, AAP abundance ranged from 0.3 to 12.04 × 10(5) cells mL(-1), which represents <1 to 18.3 % of the total bacteria. The vertical distribution of AAPs confirmed their presence in the upper parts of the water column with minimum numbers in the anoxic bottom waters. We have shown that the AAP abundance was significantly positively correlated with the water pH, and the highest proportion of photoheterotrophs was found in peat-bog lakes with a pH between 6.7 and 7.6. Our results demonstrated an influence of water acidity on the abundance of AAPs, which may reflect a fundamental difference in the microbial composition between acidic and pH neutral peat-bog lakes.

  10. 77 FR 2970 - Notice of Intent To Prepare an Environmental Assessment for the Proposed Elba BOG Compressor...

    Federal Register 2010, 2011, 2012, 2013, 2014

    2012-01-20

    ... From the Federal Register Online via the Government Publishing Office DEPARTMENT OF ENERGY Federal Energy Regulatory Commission Notice of Intent To Prepare an Environmental Assessment for the Proposed Elba BOG Compressor Project and Request for Comments on Environmental Issues; Southern LNG Company, L.L.C. The staff of the Federal...

  11. Purple Pitcher Plant (Sarracenia rosea) Dieback and Partial Community Disassembly following Experimental Storm Surge in a Coastal Pitcher Plant Bog

    PubMed Central

    Abbott, Matthew J.; Battaglia, Loretta L.

    2015-01-01

    Sea-level rise and frequent intense hurricanes associated with climate change will result in recurrent flooding of inland systems such as Gulf Coastal pitcher plant bogs by storm surges. These surges can transport salt water and sediment to freshwater bogs, greatly affecting their biological integrity. Purple pitcher plants (Sarracenia rosea) are Gulf Coast pitcher plant bog inhabitants that could be at a disadvantage under this scenario because their pitcher morphology may leave them prone to collection of saline water and sediment after a surge. We investigated the effects of storm surge water salinity and sediment type on S. rosea vitality, plant community structure, and bog soil-water conductivity. Plots (containing ≥1 ramet of S. rosea) were experimentally flooded with fresh or saline water crossed with one of three sediment types (local, foreign, or no sediment). There were no treatment effects on soil-water conductivity; nevertheless, direct exposure to saline water resulted in significantly lower S. rosea cover until the following season when a prescribed fire and regional drought contributed to the decline of all the S. rosea to near zero percent cover. There were also significant differences in plant community structure between treatments over time, reflecting how numerous species increased in abundance and a few species decreased in abundance. However, in contrast to S. rosea, most of the other species in the community appeared resilient to the effects of storm surge. Thus, although the community may be somewhat affected by storm surge, those few species that are particularly sensitive to the storm surge disturbance will likely drop out of the community and be replaced by more resilient species. Depending on the longevity of these biological legacies, Gulf Coastal pitcher plant bogs may be incapable of fully recovering if they become exposed to storm surge more frequently due to climate change. PMID:25874369

  12. Simulated thaw development of a peat plateau-bog complex in a discontinuous permafrost region, Northwest Territories, Canada

    NASA Astrophysics Data System (ADS)

    Kurylyk, Barret; Hayashi, Masaki; Quinton, William; Voss, Clifford

    2015-04-01

    Air temperatures at high latitudes have increased at rates that exceed globally averaged trends, and this warming has produced rapid permafrost degradation in many areas. In discontinuous permafrost regions of the Taiga Plains of northwestern Canada, past climate warming has created a complex landscape mosaic of fully thawed bogs/fens and remnant peat plateaus underlain by thin permafrost. The thawing of peat plateaus can alter the landscape hydrologic connectivity by creating pathways to efficiently convey water from bogs to nearby rivers and lakes. Extensive monitoring of the thermal regime of a peat plateau-bog complex in the Scotty Creek watershed (61.3° N, 121.3° W), Northwest Territories, Canada has identified rapid permafrost degradation in the past decade. In addition, satellite images indicate major landscape evolution due to permafrost thaw since 1970, and these changes have resulted in increased discharge at the watershed outlet. These long term comprehensive data facilitate the numerical modeling of idealized permafrost environments based on observed data. The objective of this research project is to elucidate fundamental processes that contribute to multi-dimensional permafrost thaw and associated hydrological changes in discontinuous permafrost regions. The thaw evolution in this peat plateau-bog complex is simulated using SUTRA, a numerical groundwater flow and coupled heat transport model that has been modified to include dynamic freeze-thaw processes. To accommodate complex surface processes, measured climate data from 1900-2010 are used to drive a separate soil-vegetation-atmosphere energy transfer model. Near-surface temperatures produced by the vertical transfer model for the peat plateau and bog are applied as the upper thermal boundary conditions for the multi-dimensional subsurface heat transport simulations in SUTRA (1900-2010). The simulated thaw development of this peat plateau will be compared to satellite imagery to assess the ability

  13. Different patterns of genetic structure of relict and isolated populations of endangered peat-bog pine (Pinus uliginosa Neumann).

    PubMed

    Wachowiak, W; Prus-Glowacki, W

    2009-01-01

    Recent changes in environmental conditions in populations of peat-bog pine (Pinus uliginosa Neumann) caused rapid decline or even extinction of the species in several stands in Central Europe. Conservation strategies for P. uliginosa require information about the evolutionary history and genetic structure of its populations. Using isozymes we assessed the genetic structure of P. uliginosa from four isolated stands in Poland and compared the results to genetic structures of other closely related pine species including eight populations of Pinus mugo, ten of Pinus sylvestris and one of Pinus uncinata. The level of genetic variability of P. uliginosa measured by the mean number of alleles per locus and average heterozygosity was similar to others related to P. uliginosa taxa from the reference group but it differs among populations. High genetic similarity was found between two populations of P. uliginosa from Low Silesian Pinewood. The populations were genetically distinct as compared to other populations including locus classicus of the species from the peat bog at Batorów Reserve. Very low genetic distance (DN = 0.002) and small genetic differentiation (GST = 0.003) were found between P. uliginosa and P. mugo in the sympatric populations of the species from Zieleniec peat bog suggesting the ongoing natural hybridisation and genetic contamination of peat-bog pine from this area. Some evidence for skew in allele frequency distribution potentially due to recent bottleneck was found in population from Low Silesian Pinewood. The analysed open pollinated progeny derived from two P. uliginosa stands from Low Silesian Pinewood showed the excess of homozygotes as compared to the maternal trees indicating high level of inbreeding (F = 0.105, F = 0.081). The results are discussed in the context of evolution of P. uliginosa populations, taxonomic relationships between the analysed species and conservation strategies for active protection of peat-bog pine. PMID:19875883

  14. Purple pitcher plant (Sarracenia rosea) Dieback and partial community disassembly following experimental storm surge in a coastal pitcher plant bog.

    PubMed

    Abbott, Matthew J; Battaglia, Loretta L

    2015-01-01

    Sea-level rise and frequent intense hurricanes associated with climate change will result in recurrent flooding of inland systems such as Gulf Coastal pitcher plant bogs by storm surges. These surges can transport salt water and sediment to freshwater bogs, greatly affecting their biological integrity. Purple pitcher plants (Sarracenia rosea) are Gulf Coast pitcher plant bog inhabitants that could be at a disadvantage under this scenario because their pitcher morphology may leave them prone to collection of saline water and sediment after a surge. We investigated the effects of storm surge water salinity and sediment type on S. rosea vitality, plant community structure, and bog soil-water conductivity. Plots (containing ≥1 ramet of S. rosea) were experimentally flooded with fresh or saline water crossed with one of three sediment types (local, foreign, or no sediment). There were no treatment effects on soil-water conductivity; nevertheless, direct exposure to saline water resulted in significantly lower S. rosea cover until the following season when a prescribed fire and regional drought contributed to the decline of all the S. rosea to near zero percent cover. There were also significant differences in plant community structure between treatments over time, reflecting how numerous species increased in abundance and a few species decreased in abundance. However, in contrast to S. rosea, most of the other species in the community appeared resilient to the effects of storm surge. Thus, although the community may be somewhat affected by storm surge, those few species that are particularly sensitive to the storm surge disturbance will likely drop out of the community and be replaced by more resilient species. Depending on the longevity of these biological legacies, Gulf Coastal pitcher plant bogs may be incapable of fully recovering if they become exposed to storm surge more frequently due to climate change. PMID:25874369

  15. Purple pitcher plant (Sarracenia rosea) Dieback and partial community disassembly following experimental storm surge in a coastal pitcher plant bog.

    PubMed

    Abbott, Matthew J; Battaglia, Loretta L

    2015-01-01

    Sea-level rise and frequent intense hurricanes associated with climate change will result in recurrent flooding of inland systems such as Gulf Coastal pitcher plant bogs by storm surges. These surges can transport salt water and sediment to freshwater bogs, greatly affecting their biological integrity. Purple pitcher plants (Sarracenia rosea) are Gulf Coast pitcher plant bog inhabitants that could be at a disadvantage under this scenario because their pitcher morphology may leave them prone to collection of saline water and sediment after a surge. We investigated the effects of storm surge water salinity and sediment type on S. rosea vitality, plant community structure, and bog soil-water conductivity. Plots (containing ≥1 ramet of S. rosea) were experimentally flooded with fresh or saline water crossed with one of three sediment types (local, foreign, or no sediment). There were no treatment effects on soil-water conductivity; nevertheless, direct exposure to saline water resulted in significantly lower S. rosea cover until the following season when a prescribed fire and regional drought contributed to the decline of all the S. rosea to near zero percent cover. There were also significant differences in plant community structure between treatments over time, reflecting how numerous species increased in abundance and a few species decreased in abundance. However, in contrast to S. rosea, most of the other species in the community appeared resilient to the effects of storm surge. Thus, although the community may be somewhat affected by storm surge, those few species that are particularly sensitive to the storm surge disturbance will likely drop out of the community and be replaced by more resilient species. Depending on the longevity of these biological legacies, Gulf Coastal pitcher plant bogs may be incapable of fully recovering if they become exposed to storm surge more frequently due to climate change.

  16. Effects of land use intensity on the full greenhouse gas balance in an Atlantic peat bog

    NASA Astrophysics Data System (ADS)

    Beetz, S.; Liebersbach, H.; Glatzel, S.; Jurasinski, G.; Buczko, U.; Höper, H.

    2012-06-01

    The assessment of emission factors for many peatlands is difficult, and reliable data on the exchange of carbon dioxide (CO2), methane (CH4) and nitrous oxide (N2O) between soil and atmosphere of these areas is particularly scarce. Reasons for this are the multitude of soil and land use combinations that control greenhouse gas exchange and the high effort associated with data acquisition. We investigated the greenhouse gas exchange of a peat bog restoration sequence over a period of 2 yr (July 2007-June 2009) in an Atlantic raised bog in Northwest Germany. We set up three sites representing different land use intensities: intensive grassland (mineral fertilizer, cattle manure and 4-5 cuts per year); extensive grassland (no fertilizer or manure, maximal 1 cutting per year); near-natural peat bog (almost no anthropogenic influence). We obtained seasonal and annual estimates of greenhouse gas exchange based on closed chamber measurements. CH4 and N2O fluxes were recorded bi-weekly, CO2 NEE determinations were carried out 3-4 weekly. To get annual sums the CH4 and N2O fluxes were interpolated linearly while NEE was modelled. The intensive grassland site emitted 548 ± 169 g CO2-C m-2 in the first and 817 ± 140 g CO2-C m-2 in the second year. The extensive grassland site showed a slight uptake in the first year (-148 ± 143 g CO2-C m-2), and a small emission of 88 ± 146 g CO2-C m-2 in the second year. In contrast to these agriculturally used sites, the near-natural site took up CO2-C in both years (-8 ± 68 g CO2-C m-2 and -127 ± 53 g CO2-C m-2). Under consideration of N2O and CH4 exchange, the total average greenhouse warming potential (GWP) for 2008 amounts to 441 ± 157 g m-2, 14 ± 152 g m-2 and 31 ± 68 g m-2 CO2-C-equivalent for the intensive grassland, the extensive grassland and the near-natural site, respectively. Despite inter-annual variability, rewetting contributes considerably to mitigating GHG emission from formerly drained peatlands. Already

  17. Summer methane fluxes from a boreal bog in northern Quebec, Canada, using eddy covariance measurements

    NASA Astrophysics Data System (ADS)

    Nadeau, Daniel F.; Rousseau, Alain N.; Coursolle, Carole; Margolis, Hank A.; Parlange, Marc B.

    2013-12-01

    A boreal bog located in the James Bay lowlands, Canada, was instrumented with an open-path gas analyzer to monitor the turbulent fluxes of methane throughout the summer of 2012. The mostly continuous eddy covariance measurements permitted the study of methane dynamics at the hourly, daily and seasonal scales. To exclude data segments for which the biological methane fluxes were underestimated due to inefficient atmospheric transport under stable stratification, we applied a novel approach based on both the atmospheric stability parameter ζ = z/L and the friction velocity u∗, where z is the measurement height and L the Obukhov length. The field measurements revealed the existence of at least one sustained ebullition event, triggered by low barometric pressures, a declining water table and increasing mechanical turbulence - suggesting that large-scale release of methane bubbles can be an important transport mechanism of methane in boreal bogs. The validity of similarity scaling for atmospheric methane under convective conditions was also assessed and the normalized standard deviations of methane concentrations did not scale well with ζ, highlighting the heterogeneity in natural methane production and release across the bog. Overall the hourly emissions ranged between -2.0 and 32.1 mg CH4 m-2 h-1, with a summertime mean of 2.4 mg CH4 m-2 h-1. At the daily scale, the two main controls on methane emissions were found to be the water table position and the peat temperature at 0.3 m under the surface. Contrary to other studies, seasonal methane emissions peaked when the water table was at its maximum distance from the surface, around mid-August. No clear diurnal pattern could be found in methane emissions, indicating that methane was produced quite deep within the peat. The seasonal emissions were estimated at 4.4 g CH4 m-2, and compared well with other observations over similar landscapes using different measurement techniques. Given that methane releases and

  18. Modeling regional groundwater flow in a peat bog complex in Ontario, Canada

    NASA Astrophysics Data System (ADS)

    Durejka, Stefan; Knorr, KLaus-Holger; Blodau, Christian; Frei, Sven

    2013-04-01

    Peatlands are important ecohydrological systems and contribute significantly to the global carbon cycle. They function as carbon sinks through CO2-sequestration but also emit methane depending i.a. on the prevailing hydrological structures. Knowledge of their hydrology including exchange between the groundwater and surface water domain is thus necessary to understand wetland environments and to determine their vulnerability to climate changes. The impact of proposed wetter conditions on wetland hydrological homeostastis in northern bogs is uncertain to this date. Elevated water tables due to changing hydrological flow patterns may affect the characteristics of wetlands as a carbon reservoir. Modeling approaches allow quantifying and qualifying of these flow patterns on a longer time scale. Luther Bog is located in Southern Ontario. The ombotrophic bog to poor fen is partially bordered by Luther Lake which inundates the area since its creation in 1952. In this study the interaction between the wetland and the adjacent lake is modeled using the fully-integrated HydroGeoSphere model. A transient three-dimensional groundwater mode is set up for a small catchment with the lake level implemented as a constant-head boundary condition. Hydraulic properties of the peat were estimated executing bail tests on multilevel piezometers at different sites within the wetland. The first hypothesis is that the wet conditions in the runoff network keep the water table in the wetland high over a specific transition zone. The Second is that there may be a reversal of flow directions over the hydrological year, due to varying boundary conditions, e.g. evapotranspiration and precipitation. First results indicate that exchange rates may be very slow. This is supported by manual measurements of little hydraulic gradients and little topographic gradients. The results also show a seasonal effect in flow directions in both, the groundwater and the surface water domain. The model will be tested

  19. The formation of basal-type uranium deposits in south central British Columbia

    SciTech Connect

    Boyle, D.R.

    1982-08-01

    The basal-type uranium deposits in south central British Columbia occur within unconsolidated, late Miocene fluvial paleochannel sediments that overlie major fault zones within the Okanagan Highlands Intrusive Complex. Five uranium deposits have been outlined to date, of which the Blizzard (4,020 metric tons U) and Tyee (650 metric tons U) are the largest. The basement intrusive complex underlying the deposits varies in age from early Cretaceous to Eocene and is comprised of quartz monzonite, granodiorite, Coryell monzonite, porphyritic granite, and pegmatite. Uranium mineralization is present in the form of uranous (ningyoite) or uranyl (saleeite, autunite) phosphates coating clastic grains and filling voids. Because of very strong reducing conditions related to large concentrations of marcasite and organic material, ningyoite is the only uranium mineral in the Tyee deposit, whereas the Blizzard deposit contains a more complex assemblage of minerals (saleeite, autunite, ningyoite). The observed paragenetic sequence of mineral precipitation in the Blizzard deposit (autunite-saleeite-ningyoite) indicates that the uranyl minerals, saleeite and autunite, are primary. Investigations of the source of the ore-forming elements (U, Ca, Mg, PO/sub 4/) showed the deposits to be formed by the infiltration into fluvial sediments of deep-seated, structurally controlled, ground waters that migrated in a well-developed regional hydrologic system within the Complex. Research indicates that the ore-forming ground waters were cold, slightly bicarbonated (150-400 ppm), highly uraniferous (10-50 ppb), and slightly oxidizing (dissolved oxygen = 2-4 ppm).

  20. The importance of dissolved free oxygen during formation of sandstone-type uranium deposits

    USGS Publications Warehouse

    Granger, Harry Clifford; Warren, C.G.

    1979-01-01

    One factor which distinguishes t, he genesis of roll-type uranium deposits from the Uravan Mineral Belt and other sandstone-type uranium deposits may be the presence and concentration of dissolved free oxygen in the ore-forming. solutions. Although dissolved oxygen is a necessary prerequisite for the formation of roll-type deposits, it is proposed that a lack of dissolved oxygen is a prerequisite for the Uravan deposits. Solutions that formed both types of deposits probably had a supergene origin and originated as meteoric water in approximate equilibrium with atmospheric oxygen. Roll-type deposits were formed where the Eh dropped abruptly following consumption of the oxygen by iron sulfide minerals and creation of kinetically active sulfur species that could reduce uranium. The solutions that formed the Uravan deposits, on the other hand, probably first equilibrated with sulfide-free ferrous-ferric detrital minerals and fossil organic matter in the host rock. That is, the uraniferous solutions lost their oxygen without lowering their Eh enough to precipitate uranium. Without oxygen, they then. became incapable of oxidizing iron sulfide minerals. Subsequent localization and formation of ore bodies from these oxygen-depleted solutions, therefore, was not necessarily dependent on large reducing capacities.

  1. Climate-growth relationships for bog-grown black spruce in northern Minnesota

    SciTech Connect

    Vogel, K.J. )

    1993-06-01

    Black spruce (Picea mariana) tree-ring chronologies were derived for three bogs in northern Minnesota. Standard chronologies were highly intercorrelated (0.72 to 0.87). The ring-width variability attributable to a common signal ranged from 38.6 to 56.8 percent which is large for closed canopy eastern forests. These chronologies exhibited great serial correlation, therefore all chronologies were autoregressively modelled prior to climatic analyses. Each chronology was compared to monthly temperature and precipitation data from a nearby weather station. Strengths of linear relationships were measured by the product-moment correlation coefficient. May and August temperatures from the previous year and March precipitation of the current year were significantly correlated with ring-width indices. These data suggest that tree-ring chronologies from mid-continental peatlands may be a valuable, though presently ignored, source of paleoclimatic data.

  2. Effect of fire on phosphorus forms in Sphagnum moss and peat soils of ombrotrophic bogs.

    PubMed

    Wang, Guoping; Yu, Xiaofei; Bao, Kunshan; Xing, Wei; Gao, Chuanyu; Lin, Qianxin; Lu, Xianguo

    2015-01-01

    The effect of burning Sphagnum moss and peat on phosphorus forms was studied with controlled combustion in the laboratory. Two fire treatments, a light fire (250 °C) and a severe fire (600 °C), were performed in a muffle furnace with 1-h residence time to simulate the effects of different forest fire conditions. The results showed that fire burning Sphagnum moss and peat soils resulted in losses of organic phosphorus (Po), while inorganic phosphorus (Pi) concentrations increased. Burning significantly changed detailed phosphorus composition and availability, with severe fires destroying over 90% of organic phosphorus and increasing the availability of inorganic P by more than twofold. Our study suggest that, while decomposition processes in ombrotrophic bogs occur very slowly, rapid changes in the form and availability of phosphorus in vegetation and litter may occur as the result of forest fires on peat soils.

  3. Deciphering the environmental and landscape evolution of Sierra Nevada (S Iberia) from bog archives

    NASA Astrophysics Data System (ADS)

    Garcia Alix, Antonio; Toney, Jaime L.; Jiménez-Moreno, Gonzalo; Ramos-Román, Maria J.; Anderson, R. Scott; Jiménez-Espejo, Francisco; Delgado Huertas, Antonio; Ruano, Patricia

    2016-04-01

    Sierra Nevada is the southernmost mountain range in the Iberian Peninsula and one of the highest in Europe. Its geomorphology was the result of Pleistocene glaciations that carved out depressions, valleys and cirques at high elevations in the metamorphic basement. Depressions gave rise to lakes and wetlands during the Holocene. Geophysical and organic geochemical analyses of biomarkers (n-alkanes) and bulk sediment (C and N ratio and isotopes) from two high elevation bogs (locally called "Borreguiles"): Borreguiles de la Virgen (BdlV) and Borreguiles de la Caldera (BdlC), have allowed us to track the hydrological evolution of the area and its relationship to climatic fluctuations of the western Mediterranean during the Holocene. Most of the bogs of this area resulted from the natural evolution of former small lakes. The records are 56 cm and 169 cm long, respectively. Geophysical data suggest that we recovered the whole sedimentary record from BdlC; however, there are some post-glacial sediments remaining below the BdlV core that we could not recover due to hard-ground conditions. During the early and middle Holocene, aquatic conditions predominated in BdlV compared to the most recent part of the record (low C/N values and high proportion of aquatic plants (Paq) deduced from the n-alkanes) suggesting a lake environment whose water level gradually decreased until ˜5.5 cal ky BP. This aridity trend is also observed in nearby records such as at Laguna de Río Seco (LdRS), a result of the African Humid Period demise. Carbon and nitrogen isotopes were higher during this interval, which might suggest more algae activity, in agreement with the highest concentrations of the algae Pediastrum in the area. There is an important development of terrestrial plants, a real bog stage (C/N higher than 20, high TOC, lower Paq) in both records from ˜5.5 to 3.5-3.0 cal ky BP. Those hydrological changes in the landscape might be related to a possible change in the source of

  4. The Wonderful World of Wetlands (WWW): Bogs, fens, marshes and swamps and their global environmental significance

    NASA Astrophysics Data System (ADS)

    Shotyk, W.

    2012-04-01

    Bogs, fens, marshes, and swamps are waterlogged ecosystems where organic soils form and peat accumulates. These are remarkably diverse ecosystems and represent an important component of the biodiversity found on Earth. Their geochemical function is dominated by their predominately anoxic condition which has some important consequences. Best known as reservoirs and reactors for a significant part of our surface freshwater resources, and impacting their chemical composition in remarkable ways, they also have a significant influence on the atmosphere, removing CO2 and adding CH4. The contemporary view during the past centuries was that these were wastelands in need of improving by drainage. Today, however, in some circles at least, the remaining wetlands are valued ecosystems, and the soils they contain archives of climate change, human history and atmospheric pollution.

  5. Effects of bryophytes on succession from alkaline marsh to Sphagnum bog

    SciTech Connect

    Glime, J.M.; Wetzel, R.G.; Kennedy, B.J.

    1982-10-01

    The alkaline eastern marsh of Lawrence Lake, a marl lake in southwestern Michigan, was sampled by randomly placed line transects to determine the bryophyte cover and corresponding vascular plant zones. Cluster analysis indicated three distinct bryophyte zones which correspond with the recognized vascular plant zones. Mosses occupied over 50% of the surface in some areas. Invasion of Sphagnum, vertical zonation of the mosses on hummocks, zonation with distance from the lake, the abundance of non-Sphagnum moss hummocks, and the ability of the non-Sphagnum species to lower the pH of marsh water during laboratory incubations are evidence that non-Sphagnum mosses facilitate succession from alkaline marsh to Sphagnum bog.

  6. Effect of fire on phosphorus forms in Sphagnum moss and peat soils of ombrotrophic bogs.

    PubMed

    Wang, Guoping; Yu, Xiaofei; Bao, Kunshan; Xing, Wei; Gao, Chuanyu; Lin, Qianxin; Lu, Xianguo

    2015-01-01

    The effect of burning Sphagnum moss and peat on phosphorus forms was studied with controlled combustion in the laboratory. Two fire treatments, a light fire (250 °C) and a severe fire (600 °C), were performed in a muffle furnace with 1-h residence time to simulate the effects of different forest fire conditions. The results showed that fire burning Sphagnum moss and peat soils resulted in losses of organic phosphorus (Po), while inorganic phosphorus (Pi) concentrations increased. Burning significantly changed detailed phosphorus composition and availability, with severe fires destroying over 90% of organic phosphorus and increasing the availability of inorganic P by more than twofold. Our study suggest that, while decomposition processes in ombrotrophic bogs occur very slowly, rapid changes in the form and availability of phosphorus in vegetation and litter may occur as the result of forest fires on peat soils. PMID:24630445

  7. Sorption of radioiodide in an acidic, nutrient-poor boreal bog: insights into the microbial impact.

    PubMed

    Lusa, M; Bomberg, M; Aromaa, H; Knuutinen, J; Lehto, J

    2015-05-01

    Batch sorption experiments were conducted to evaluate the sorption behaviour of iodide and the microbial impact on iodide sorption in the surface moss, subsurface peat, gyttja, and clay layers of a nutrient-poor boreal bog. The batch distribution coefficient (Kd) values of iodide decreased as a function of sampling depth. The highest Kd values, 4800 L/Kg dry weight (DW) (geometric mean), were observed in the fresh surface moss and the lowest in the bottom clay (geometric mean 90 mL/g DW). In the surface moss, peat and gyttja layers, which have a high organic matter content (on average 97%), maximum sorption was observed at a pH between ∼ 4 and 5 and in the clay layer at pH 2. The Kd values were significantly lower in sterilized samples, being 20-fold lower than the values found for the unsterilized samples. In addition, the recolonization of sterilized samples with a microbial population from the fresh samples restored the sorption capacity of surface moss, peat and gyttja samples, indicating that the decrease in the sorption was due to the destruction of microbes and supporting the hypothesis that microbes are necessary for the incorporation of iodide into the organic matter. Anoxic conditions reduced the sorption of iodide in fresh, untreated samples, similarly to the effect of sterilization, which supports the hypothesis that iodide is oxidized into I2/HIO before incorporation into the organic matter. Furthermore, the Kd values positively correlated with peroxidase activity in surface moss, subsurface peat and gyttja layers at +20 °C, and with the bacterial cell counts obtained from plate count agar at +4 °C. Our results demonstrate the importance of viable microbes for the sorption of iodide in the bog environment, having a high organic matter content and a low pH.

  8. Ecohydrology by thinking outside the bog: Shifting paradigms in an era of shifting peatland ecosystems

    NASA Astrophysics Data System (ADS)

    Waddington, James; Moore, Paul

    2016-04-01

    Large shifts in vegetation distributions are occurring worldwide and at unprecedented rates. The most extreme of these regime shifts are expected to occur at ecosystem boundaries of both semi-arid and semi-humid landscapes. Despite extensive hydrological research on the interactions between water and semi-arid ecosystems, research in peatlands on the wet end of ecosystem continuum has been "bogged down" (pun fully intended) by the traditional conceptual models (paradigms?) of peatland hydrology and ecology. The consequences of this "thinking" are large given that northern peatlands provide important global and regional ecosystem services (carbon storage, water storage, and biodiversity). This is especially true because peatlands face increases in the severity, areal extent, and frequency of climate-mediated (e.g., wildfire, drought) and land-use change (e.g., drainage, flooding, and mining) disturbances placing the future security of these critical ecosystem services in doubt. We use the word doubt because while numerical modelling studies predict peatland regime shifts and the demise of global peat stocks, there is growing evidence that peatlands are self-regulating ecosystems dominated by negative ecohydrological feedbacks that stabilize the aforementioned ecosystem services through high ecosystem resilience to disturbance. This raises several important hydrological questions? "Is there field evidence of peatland regime shifts? If so, what are the potential impacts of these shifts on water resources and watershed management? If not, are researchers actually looking in the right places (or times)? In this presentation we explore the need for a "thinking outside the bog" in order to understand the ecohydrological consequences of transformative landscape change caused by peatland regime shifts. With reference to over two decades of field research, recent advances with our Peatland Hydrological Impacts model and recent research examining primary peat formation, we

  9. Sorption of radioiodide in an acidic, nutrient-poor boreal bog: insights into the microbial impact.

    PubMed

    Lusa, M; Bomberg, M; Aromaa, H; Knuutinen, J; Lehto, J

    2015-05-01

    Batch sorption experiments were conducted to evaluate the sorption behaviour of iodide and the microbial impact on iodide sorption in the surface moss, subsurface peat, gyttja, and clay layers of a nutrient-poor boreal bog. The batch distribution coefficient (Kd) values of iodide decreased as a function of sampling depth. The highest Kd values, 4800 L/Kg dry weight (DW) (geometric mean), were observed in the fresh surface moss and the lowest in the bottom clay (geometric mean 90 mL/g DW). In the surface moss, peat and gyttja layers, which have a high organic matter content (on average 97%), maximum sorption was observed at a pH between ∼ 4 and 5 and in the clay layer at pH 2. The Kd values were significantly lower in sterilized samples, being 20-fold lower than the values found for the unsterilized samples. In addition, the recolonization of sterilized samples with a microbial population from the fresh samples restored the sorption capacity of surface moss, peat and gyttja samples, indicating that the decrease in the sorption was due to the destruction of microbes and supporting the hypothesis that microbes are necessary for the incorporation of iodide into the organic matter. Anoxic conditions reduced the sorption of iodide in fresh, untreated samples, similarly to the effect of sterilization, which supports the hypothesis that iodide is oxidized into I2/HIO before incorporation into the organic matter. Furthermore, the Kd values positively correlated with peroxidase activity in surface moss, subsurface peat and gyttja layers at +20 °C, and with the bacterial cell counts obtained from plate count agar at +4 °C. Our results demonstrate the importance of viable microbes for the sorption of iodide in the bog environment, having a high organic matter content and a low pH. PMID:25752706

  10. High methane emissions dominate annual greenhouse gas balances 30 years after bog rewetting

    NASA Astrophysics Data System (ADS)

    Vanselow-Algan, M.; Schmidt, S. R.; Greven, M.; Fiencke, C.; Kutzbach, L.; Pfeiffer, E.-M.

    2015-02-01

    Natural peatlands are important carbon sinks and sources of methane (CH4). In contrast, drained peatlands turn from a carbon sink to a carbon source and potentially emit nitrous oxide (N2O). Rewetting of peatlands thus implies climate change mitigation. However, data about the time span that is needed for the re-establishment of the carbon sink function by restoration is scarce. We therefore investigated the annual greenhouse gas (GHG) balances of three differently vegetated bog sites 30 years after rewetting. All three vegetation communities turned out to be sources of carbon dioxide (CO2) ranging between 0.6 ± 1.43 t CO2 ha-2 yr-1 (Sphagnum-dominated vegetation) and 3.09 ± 3.86 t CO2 ha-2 yr-1 (vegetation dominated by heath). While accounting for the different global warming potential (GWP) of the three greenhouse gases, the annual GHG balance was calculated. Emissions ranged between 25 and 53 t CO2-eq ha-1 yr-1 and were dominated by large emissions of CH4 (22 up to 51 t CO2-eq ha-1 yr-1), while highest rates were found at purple moor grass (Molinia caerulea) stands. These are to our knowledge the highest CH4 emissions so far reported for bog ecosystems in temperate Europe. As the restored area was subject to large fluctuations in water table, we conclude that the high CH4 emission rates were caused by a combination of both the temporal inundation of the easily decomposable plant litter of this grass species and the plant-mediated transport through its tissues. In addition, as a result of the land use history, the mixed soil material can serve as an explanation. With regards to the long time span passed since rewetting, we note that the initial increase in CH4 emissions due to rewetting as described in the literature is not limited to a short-term period.

  11. Origin of lead in eight Central European peat bogs determined from isotope ratios, strengths, and operation times of regional pollution sources.

    PubMed

    Novák, Martin; Emmanuel, Simon; Vile, Melanie A; Erel, Yigal; Véron, Alain; Paces, Tomás; Wieder, R Kelman; Vanecek, Mirko; Stepánová, Markéta; Brízová, Eva; Hovorka, Jan

    2003-02-01

    Lead originating from coal burning, gasoline burning, and ore smelting was identified in 210Pb-dated profiles through eight peat bogs distributed over an area of 60,000 km2. The Sphagnum-dominated bogs were located mainly in mountainous regions of the Czech Republic bordering with Germany, Austria, and Poland. Basal peat 14C-dated at 11,000 years BP had a relatively high 206Pb/207Pb ratio (1.193). Peat deposited around 1800 AD had a lower 206Pb/207Pb ratio of 1.168-1.178, indicating that environmental lead in Central Europe had been largely affected by human activity (smelting) even before the beginning of the Industrial Revolution. Five of the sites exhibited a nearly constant 206Pb/207Pb ratio (1.175) throughout the 19th century, resembling the "anthropogenic baseline" described in Northern Europe (1.17). At all sites, the 206Pb/207Pb ratio of peat decreased at least until 1980; at four sites, a reversal to more radiogenic values (higher 206Pb/207Pb), typical of easing pollution, was observed in the following decade (1980-1990). A time series of annual outputs for 14 different mining districts dispersing lead into the environment has been constructed for the past 200 years. The production of Ag-Pb, coal, and leaded gasoline peaked in 1900, 1980, and 1980, respectively. In contrast to other European countries, no peak in annual Pb accumulation rates was found in 1900, the year of maximum ore smelting. The highest annual Pb accumulation rates in peat were consistent with the highest Pb emission rates from coal-fired power plants and traffic (1980). Although maximum coal and gasoline production coincided in time, their isotope ratios were unique. The mean measured 206Pb/207Pb ratios of local coal, ores, and gasoline were 1.19, 1.16, and 1.11, respectively. A considerable proportion of coal emissions, relative to gasoline emisions, was responsible for the higher 206Pb/207Pb ratios in the recent atmosphere (1.15) compared to Western Europe (1.10). As in West European

  12. Summary of reconnaissance for radioactive deposits in Alaska, 1945-1954, and an appraisal of Alaskan uranium possibilities

    USGS Publications Warehouse

    Wedow, Helmuth

    1956-01-01

    carnotite-type deposits. The chief of these areas is the Alaska Peninsula-Cook Inlet area which encompasses most of the reported occurrences of the prospectors' carnotite-type samples. Alaska is also potentially favorable for the occurrence of large bodies of the very low-grade uraniferous sedimentary rocks, such as phosphorites and black shales. This type of deposit, however, has not received much study because of the emphasis on the search for bonanza-type high-grade ores. Uraniferous phosphorites similar to those of Idaho, Montana, and Wyoming occur in northern Alaska on the north flank of the Brooks Range; black shales comparable to the uraniferous shales of the Chattanooga formation of southeastern United States have been noted along the Yukon River near the international boundary. Placer deposits in Alaska have some small potential for the production of the radioactive elements as byproducts of gold- and tin-placer mining. the placer area believed to have the relatively greatest potential in Alaska lies in the Kahiltna River valley where concentrates are known to contain such commercial minerals as ilmenite, cassiterite, platinum, and gold in addition to uranothorianite and monazite. The possibilities of the natural fluids--water and petroleum--have not yet been tested in Alaska to any great extent. Studies of fluids are in progress to determine whether they may be used to discover and define areas potentially favorable for the occurrence of uraniferous lodes.

  13. How suitable are peat cores to study historical deposition of PAHs?

    PubMed

    Thuens, Sabine; Blodau, Christian; Radke, Michael

    2013-04-15

    Ombrotrophic peat bogs are natural archives of atmospheric pollution, their depth profiles can be used to study the deposition chronology of harmful contaminants. Prerequisites for deriving historical deposition rates from the peat archive are that contaminants are persistent and immobile in the peat and that the applied dating technique is accurate. To examine these requirements and the accuracy of peat archives for polycyclic aromatic hydrocarbons (PAHs) 12 peat profiles were sampled in 4 bogs in Ontario, Canada, as well as surface peat in one bog. Additionally we carried out laboratory incubations; no degradation occurred over a 3-year period in these experiments. The standard deviations of PAH concentrations in surface samples and of PAH inventories in whole cores was approximately 30%, and concentrations in surface peat were on average 50% higher in hollows than in hummocks. No indications for mobility of PAHs were observed in peat. Temporal deposition trends inferred from peat cores were generally in agreement with trends derived from a sediment core sampled close by but deposition rates to the sediment were substantially higher. A major source of uncertainty was the rather coarse vertical sampling resolution of 5 cm which introduced substantial uncertainty in the dating of the individual segments. This caused variations of the deposition rates up to 70% per PAH between three replicate cores, and it also impedes the identification of deposition peaks. Overall, we conclude that peat cores are suitable archives for inferring atmospheric deposition trends, but due to their relatively low temporal resolution short-term events may not be identified and the development of sampling methods that allow a higher vertical resolution would greatly improve the performance of the method. The analysis of more than one core per site is suggested to provide a realistic estimate of the historic deposition and total inventories.

  14. How suitable are peat cores to study historical deposition of PAHs?

    PubMed

    Thuens, Sabine; Blodau, Christian; Radke, Michael

    2013-04-15

    Ombrotrophic peat bogs are natural archives of atmospheric pollution, their depth profiles can be used to study the deposition chronology of harmful contaminants. Prerequisites for deriving historical deposition rates from the peat archive are that contaminants are persistent and immobile in the peat and that the applied dating technique is accurate. To examine these requirements and the accuracy of peat archives for polycyclic aromatic hydrocarbons (PAHs) 12 peat profiles were sampled in 4 bogs in Ontario, Canada, as well as surface peat in one bog. Additionally we carried out laboratory incubations; no degradation occurred over a 3-year period in these experiments. The standard deviations of PAH concentrations in surface samples and of PAH inventories in whole cores was approximately 30%, and concentrations in surface peat were on average 50% higher in hollows than in hummocks. No indications for mobility of PAHs were observed in peat. Temporal deposition trends inferred from peat cores were generally in agreement with trends derived from a sediment core sampled close by but deposition rates to the sediment were substantially higher. A major source of uncertainty was the rather coarse vertical sampling resolution of 5 cm which introduced substantial uncertainty in the dating of the individual segments. This caused variations of the deposition rates up to 70% per PAH between three replicate cores, and it also impedes the identification of deposition peaks. Overall, we conclude that peat cores are suitable archives for inferring atmospheric deposition trends, but due to their relatively low temporal resolution short-term events may not be identified and the development of sampling methods that allow a higher vertical resolution would greatly improve the performance of the method. The analysis of more than one core per site is suggested to provide a realistic estimate of the historic deposition and total inventories. PMID:23500826

  15. Using stable isotopes of water to re-evaluate the recharge/discharge functions of North American bogs and fens

    NASA Astrophysics Data System (ADS)

    Levy, Zeno; Siegel, Donald; Glaser, Paul; Dasgupta, Soumitri

    2014-05-01

    In North American mires hydrologists commonly find raised bog crests and low-lying fen water tracks to be focal points for groundwater recharge and discharge, respectively. To further test these observations we synoptically surveyed vertical profiles of peat pore water δ18O/δ2H and major mineral solutes from a range of bog and fen landforms across the Glacial Lake Agassiz Peatlands (GLAP) of northern Minnesota. We also sampled a detailed transect through a 150 km2 bog-fen complex in the Red Lake II peatland watershed of the GLAP. The molar ratios of Ca/Mg in the pore water beneath the Red Lake II bog crest are depleted in Mg with respect to the atmospheric average of 3.6, indicative of preferential flushing of Mg from the peat by meteoric recharge. Higher solute concentrations in the middle of the peat profile at an adjacent fen show focused groundwater discharge with Ca/Mg ratios of ~1.4, similar to that of water from local wells tapping underlying glacial till. However, contrary to expectations, we find evidence that modern recharge has penetrated throughout the peat column beneath both bog and fen landforms throughout the GLAP. Landform surface features control the isotopic recharge value. These landform-specific isotope signatures propagate through vertical pore water profiles. Pore waters deeper than 0.5 m partition into discrete ranges of δ18O according to three a priori landform classifications: 1) -11.9 ± 0.4 o for bog crests, 2) -10.6 ± 0.1 o for Sphagnum lawns, and 3) -8.8 ± 1.0 o for fen water tracks. The fen water tracks have standing water at their surface that is seasonally enriched by isotope fractionating evaporation and therefore fingerprints recharge to depths ≥3 m. Incongruities between isotope and solute mixing trends may be related to the dual porosity nature of peat and matrix diffusion, which could supply solutes to active pore spaces following flushing by meteoric recharge. This buffering of base solutes in the deep peat may

  16. Optimization of UA of heat exchangers and BOG compressor exit pressure of LNG boil-off gas reliquefaction system using exergy analysis

    NASA Astrophysics Data System (ADS)

    Kochunni, Sarun Kumar; Ghosh, Parthasarathi; Chowdhury, Kanchan

    2015-12-01

    Boil-off gas (BOG) generation and its handling are important issues in Liquefied natural gas (LNG) value chain because of economic, environment and safety reasons. Several variants of reliquefaction systems of BOG have been proposed by researchers. Thermodynamic analyses help to configure them and size their components for improving performance. In this paper, exergy analysis of reliquefaction system based on nitrogen-driven reverse Brayton cycle is carried out through simulation using Aspen Hysys 8.6®, a process simulator and the effects of heat exchanger size with and without related pressure drop and BOG compressor exit pressure are evaluated. Nondimensionalization of parameters with respect to the BOG load allows one to scale up or down the design. The process heat exchanger (PHX) requires much higher surface area than that of BOG condenser and it helps to reduce the quantity of methane vented out to atmosphere. As pressure drop destroys exergy, optimum UA of PHX decreases for highest system performance if pressure drop is taken into account. Again, for fixed sizes of heat exchangers, as there is a range of discharge pressures of BOG compressor at which the loss of methane in vent minimizes, the designer should consider choosing the pressure at lower value.

  17. Overriding control of methane flux temporal variability by water table dynamics in a Southern Hemisphere, raised bog

    NASA Astrophysics Data System (ADS)

    Goodrich, J. P.; Campbell, D. I.; Roulet, N. T.; Clearwater, M. J.; Schipper, L. A.

    2015-05-01

    There are still large uncertainties in peatland methane flux dynamics and insufficient understanding of how biogeochemical processes scale to ecosystems. New Zealand bogs differ from Northern Hemisphere ombrotrophic systems in climatic setting, hydrology, and dominant vegetation, offering an opportunity to evaluate our knowledge of peatland methane biogeochemistry gained primarily from northern bogs and fens. We report eddy covariance methane fluxes from a raised bog in New Zealand over 2.5 years. Annual total methane flux in 2012 was 29.1 g CH4 m-2 yr-1, whereas during a year with a severe drought (2013) it was 20.6 g CH4 m-2 yr-1, both high compared to Northern Hemisphere bogs and fens. Drier conditions led to a decrease in fluxes from ~100 mg CH4 m-2 d-1 to ~20 mg CH4 m-2 d-1, and subsequent slow recovery of flux after postdrought water table rise. Water table depth regulated the temperature sensitivity of methane fluxes, and this sensitivity was greatest when the water table was within 100 mm of the surface, corresponding to the shallow rooting zone of the dominant vegetation. A correlation between daytime CO2 uptake and methane fluxes emerged during times with shallow water tables, suggesting that controls on methane production were critical in determining fluxes, more so than oxidation. Water table recession through this shallow zone led to increasing methane fluxes, whereas changes in temperature during these periods were not correlated. Models of methane fluxes should consider drought-induced lags in seasonal flux recovery that depend on drought characteristics and location of the critical zone for methane production.

  18. Effects of land use intensity on the full greenhouse gas balance in an Atlantic peat bog

    NASA Astrophysics Data System (ADS)

    Beetz, S.; Liebersbach, H.; Glatzel, S.; Jurasinski, G.; Buczko, U.; Höper, H.

    2013-02-01

    Wetlands can either be net sinks or net sources of greenhouse gases (GHGs), depending on the mean annual water level and other factors like average annual temperature, vegetation development, and land use. Whereas drained and agriculturally used peatlands tend to be carbon dioxide (CO2) and nitrous oxide (N2O) sources but methane (CH4) sinks, restored (i.e. rewetted) peatlands rather incorporate CO2, tend to be N2O neutral and release CH4. One of the aims of peatland restoration is to decrease their global warming potential (GWP) by reducing GHG emissions. We estimated the greenhouse gas exchange of a peat bog restoration sequence over a period of 2 yr (1 July 2007-30 June 2009) in an Atlantic raised bog in northwest Germany. We set up three study sites representing different land use intensities: intensive grassland (deeply drained, mineral fertilizer, cattle manure and 4-5 cuts per year); extensive grassland (rewetted, no fertilizer or manure, up to 1 cutting per year); near-natural peat bog (almost no anthropogenic influence). Daily and annual greenhouse gas exchange was estimated based on closed-chamber measurements. CH4 and N2O fluxes were recorded bi-weekly, and net ecosystem exchange (NEE) measurements were carried out every 3-4 weeks. Annual sums of CH4 and N2O fluxes were estimated by linear interpolation while NEE was modelled. Regarding GWP, the intensive grassland site emitted 564 ± 255 g CO2-C equivalents m-2 yr-1 and 850 ± 238 g CO2-C equivalents m-2 yr-1 in the first (2007/2008) and the second (2008/2009) measuring year, respectively. The GWP of the extensive grassland amounted to -129 ± 231 g CO2-C equivalents m-2 yr-1 and 94 ± 200 g CO2-C equivalents m-2 yr-1, while it added up to 45 ± 117 g CO2-C equivalents m-2 yr-1 and -101 ± 93 g CO2-C equivalents m-2 yr-1 in 2007/08 and 2008/09 for the near-natural site. In contrast, in calendar year 2008 GWP aggregated to 441 ± 201 g CO2-C equivalents m-2 yr-1, 14 ± 162 g CO2-C equivalents m-2 yr-1

  19. Comparative characteristic of the sphagnum moss and peat of upland bogs in Siberia, Russia and central part of Germany

    NASA Astrophysics Data System (ADS)

    Mezhibor, Antonina; Podkozlin, Ivan

    2013-04-01

    This research represents the results of the ICP-MS study for the moss and peat samples from two upland bogs of Germany and one bog from Siberia, Russia (Tomsk region). Moss and upland peat are widely used for ecological studies. These substances enable to detect atmospheric pollution because of the peculiar structure of sphagnum moss. According to the obtained results, we can resume that moss and peat in Tomsk region are more enriched in such chemical elements as Cr, Fe, As, Sr, Y, Zr, Ba, La, Ce, Nd, Sm, Eu, Tb, Yb, Lu, Hf, Hg, Th, and U. The samples from Germany are more enriched in Mn, Cu, Zn, and Se. The geochemical composition of the bogs reflects the specificity of industries that pollute the atmosphere with definite chemical elements. Thus, REE, Th and U in the moss and peat of Tomsk region can originate from nuclear facility near the Tomsk city. Coal combustion in power stations can be the source of Cr, As, Sr and REE as well. Mn, Cu, Zn, and Se possibly can originate from metallurgical facilities in Germany.

  20. The microbial impact on the sorption behaviour of selenite in an acidic, nutrient-poor boreal bog.

    PubMed

    Lusa, M; Bomberg, M; Aromaa, H; Knuutinen, J; Lehto, J

    2015-09-01

    (79)Se is among the most important long lived radionuclides in spent nuclear fuel and selenite, SeO3(2-), is its typical form in intermediate redox potential. The sorption behaviour of selenite and the bacterial impact on the selenite sorption in a 7-m-deep profile of a nutrient-poor boreal bog was studied using batch sorption experiments. The batch distribution coefficient (Kd) values of selenite decreased as a function of sampling depth and highest Kd values, 6600 L/kg dry weight (DW), were observed in the surface moss and the lowest in the bottom clay at 1700 L/kg DW. The overall maximum sorption was observed at pH between 3 and 4 and the Kd values were significantly higher in unsterilized compared to sterilized samples. The removal of selenite from solution by Pseudomonas sp., Burkholderia sp., Rhodococcus sp. and Paenibacillus sp. strains isolated from the bog was affected by incubation temperature and time. In addition, the incubation of sterilized surface moss, subsurface peat and gyttja samples with added bacteria effectively removed selenite from the solution and on average 65% of selenite was removed when Pseudomonas sp. or Burkholderia sp. strains were used. Our results demonstrate the important role of bacteria for the removal of selenite from the solution phase in the bog environment, having a high organic matter content and a low pH.

  1. Sphagnum N and P Stoichiometry Indicates P-limitation on N2 Fixation in Ombrotrophic Bogs

    NASA Astrophysics Data System (ADS)

    Zivkovic, T.; Moore, T. R.; Disney, K.

    2015-12-01

    Biological N2 fixation is an important N input in ombrotrophic, nutrient poor and Sphagnum dominated bogs. As an energetically costly process, by which each N2 molecule is fixed to a cost of 16ATP molecules, N2 fixation might be P limited process. In this study we tested whether moss P and N concentrations, and N:P ratios could explain N2 fixation in the top 6cm photosynthetically active Sphagnum moss across eight ombrotrophic bogs along south-north geographical gradient in Ontario and Quebec. Under constant environmental conditions, we incubated subsamples of the surface Sphagnum mosses by using both, acetylene reduction assays (ARA) and 15N2 enriched method to measure N2 fixation rates. Same subsamples were later analyzed for N and P concentrations. Our preliminary data show that the increase of P concentration within moss capitula is related to a significant linear increase of ARA rates (R2=0.18, p<0.0001, N=150). N:P ratios showed a significant negative linear relationship with ARA (R2=0.34, p<0.0001, N=150) indicating that P limitation in the photosynthetically active part of mosses in bogs may also indicate P limitation on microbial N2 fixation

  2. The microbial impact on the sorption behaviour of selenite in an acidic, nutrient-poor boreal bog.

    PubMed

    Lusa, M; Bomberg, M; Aromaa, H; Knuutinen, J; Lehto, J

    2015-09-01

    (79)Se is among the most important long lived radionuclides in spent nuclear fuel and selenite, SeO3(2-), is its typical form in intermediate redox potential. The sorption behaviour of selenite and the bacterial impact on the selenite sorption in a 7-m-deep profile of a nutrient-poor boreal bog was studied using batch sorption experiments. The batch distribution coefficient (Kd) values of selenite decreased as a function of sampling depth and highest Kd values, 6600 L/kg dry weight (DW), were observed in the surface moss and the lowest in the bottom clay at 1700 L/kg DW. The overall maximum sorption was observed at pH between 3 and 4 and the Kd values were significantly higher in unsterilized compared to sterilized samples. The removal of selenite from solution by Pseudomonas sp., Burkholderia sp., Rhodococcus sp. and Paenibacillus sp. strains isolated from the bog was affected by incubation temperature and time. In addition, the incubation of sterilized surface moss, subsurface peat and gyttja samples with added bacteria effectively removed selenite from the solution and on average 65% of selenite was removed when Pseudomonas sp. or Burkholderia sp. strains were used. Our results demonstrate the important role of bacteria for the removal of selenite from the solution phase in the bog environment, having a high organic matter content and a low pH. PMID:26048060

  3. Low impact of dry conditions on the CO2 exchange of a Northern-Norwegian blanket bog

    NASA Astrophysics Data System (ADS)

    Lund, Magnus; Bjerke, J. W.; Drake, B. G.; Engelsen, O.; Hansen, G. H.; Parmentier, F. J. W.; Powell, T. L.; Silvennoinen, H.; Sottocornola, M.; Tømmervik, H.; Weldon, S.; Rasse, D. P.

    2015-02-01

    Northern peatlands hold large amounts of organic carbon (C) in their soils and are as such important in a climate change context. Blanket bogs, i.e. nutrient-poor peatlands restricted to maritime climates, may be extra vulnerable to global warming since they require a positive water balance to sustain their moss dominated vegetation and C sink functioning. This study presents a 4.5 year record of land-atmosphere carbon dioxide (CO2) exchange from the Andøya blanket bog in northern Norway. Compared with other peatlands, the Andøya peatland exhibited low flux rates, related to the low productivity of the dominating moss and lichen communities and the maritime settings that attenuated seasonal temperature variations. It was observed that under periods of high vapour pressure deficit, net ecosystem exchange was reduced, which was mainly caused by a decrease in gross primary production. However, no persistent effects of dry conditions on the CO2 exchange dynamics were observed, indicating that under present conditions and within the range of observed meteorological conditions the Andøya blanket bog retained its C uptake function. Continued monitoring of these ecosystem types is essential in order to detect possible effects of a changing climate.

  4. A stacked record of late-Holocene moisture variability from three raised bogs in Maine

    NASA Astrophysics Data System (ADS)

    Clifford, M. J.; Booth, R. K.

    2011-12-01

    During the past century, drought has caused substantial social, economic, and ecological changes in North America. Semi-arid regions of the western United States have been particularly vulnerable to drought and drought impacts. However, drought has been less frequent and severe in humid regions of North America during the past century, leading to the perception that these regions are not particularly vulnerable to hydroclimatic change. Although the tree-ring record provides a detailed perspective on drought frequency and duration for the past millennium in the western US, much less is known about the long-term history of water balance in humid regions like the Northeast. To better understand the long-term history of moisture variability in this region, we developed records of past hydroclimate variability spanning the past 3000 years from three raised bogs in Maine. We used testate amoeba-inferred water table depths and measurements of the degree of peat decomposition to reconstruct the paleohydrology at each site. Proxy hydroclimate records from these bogs were combined (stacked), creating a single, regional record of hydroclimate variability. Our results reveal that droughts longer or more severe than any recorded during the 20th century have been common in the region, with particularly prominent multidecadal-to-centennial scale droughts centered on ~1800 yr BP, ~1650 yr BP, ~850 yr BP, and ~550 yr BP. Hydroclimate variability was greatest during the Medieval Climate Anomaly, a time period of relative warmth in much of the Northern Hemisphere. Droughts in Maine during the past century have been associated with northerly wind anomalies and anomalously cool sea surface temperatures in the adjacent northwestern North Atlantic, patterns that are likely associated with broader circulation features such as those associated with the North Atlantic Oscillation. Droughts of the past 3000 years may have been characterized by similar responses to the coupled ocean

  5. Water and Energy Exchanges over a Subarctic Bog in Northern Quebec, Canada

    NASA Astrophysics Data System (ADS)

    Isabelle, P.; Nadeau, D. F.; Rousseau, A. N.

    2013-12-01

    A significant fraction of the energy supply to eastern Canada and to the northeastern US comes from large hydropower plants located in the Canadian boreal shield. For instance, the La Grande River watershed near James Bay (Canada), hosts a hydropower complex producing nearly 40% of the overall peak load of Quebec. In this northern, remote and vast (≈100,000 km2) watershed, boreal forest is predominant, but wetlands (25% of the surface cover) are of key importance to the river's water budget. Unfortunately, little is known about how boreal wetlands affect regional hydrological processes, and hence, how they contribute to inflows to hydropower reservoirs. This study aims to gain a deeper understanding of evapotranspiration processes over boreal wetlands, based on field observations. The study site is a 60-ha bog (53.7°N, 78.2°W) located next to the Necopastic River, a tributary of the La Grande River. The peatland is of ombrotrophic type, meaning that it receives most of its water and nutrients from precipitation. The analysis relies on data collected by a flux tower during a field campaign throughout summer 2012., as well as detailed measurements of the water budget in this sub-watershed. One key finding is that the atmosphere is neutrally-stratified for more than 60% of the summer. The impact of this unusual feature of the atmospheric boundary layer on water vapor fluxes is carefully analyzed. As expected, eddy covariance evapotranspiration data compared well with classical formulas (Priestley-Taylor, Penman, Penman-Monteith, FAO), particularly with Priestley-Taylor. Given nearly all these formulations command direct measurements or estimations of net radiation, and that the cost of net radiometers is prohibitive, we tested the less frequently used profile method, which simply requires one or two additional measurement levels of wind speed, temperature and humidity. The latter method led to promising results, especially considering its ease of implementation

  6. Effects of Nutrient Addition on Belowground Stoichiometry and Microbial Activity in an Ombrotrophic Bog

    NASA Astrophysics Data System (ADS)

    Pinsonneault, A. J.; Moore, T. R.; Roulet, N. T.

    2015-12-01

    Ombrotrophic bogs are both nutrient-poor systems and important carbon (C) sinks yet there remains a dearth of information on the stoichiometry of C, nitrogen (N), phosphorus (P), and potassium (K), an important determinant of substrate quality for microorganisms, in these systems. In this study, we quantified the C, N, P, and K concentrations and stoichiometric ratios of both soil organic matter (SOM) and dissolved organic matter (DOM) as well as microbial extracellular enzyme activity from 0 - 10cm depth in a long-term fertilization experiment at Mer Bleue bog, Ontario, Canada. Though trends in C:N, C:P, and C:K between SOM and DOM seem to follow one another, preliminary results indicate that the stoichiometric ratios of DOM were at least an order of magnitude smaller than those of DOM suggesting that nutrient fertilization impacts the quality of DOM as a microbial substrate to a greater degree than SOM. C:N decreased with greater nitrogen addition but C:P and C:K increased; the magnitude of that increase being smaller in NPK treatments relative to N-only treatments suggesting co-limitation by P and/or K. This is further supported by the increase in activity of both the C-cycling enzyme, β-D-glucosidase (bdG), and the P-cycling enzyme, phosphatase (Phos), with greater nitrogen addition; particularly in NPK-treatments for bdG and N-only treatments for Phos. The activity of the N-cycling enzyme, N-acetyl-β-D-glucosaminidase, and the C-cycling enzyme, phenol oxidase, with greater N-addition suggests a decreased need to breakdown organic nitrogen to meet microbial N-requirements in the former and N-inhibition in the latter consistent with findings in the literature. Taken together, these results suggest that higher levels of nutrients impact both microbial substrate quality as well as the activity of microbial enzymes that are key in the decomposition process which may ultimately decrease the ability of peatlands to sequester carbon.

  7. High methane emissions dominated annual greenhouse gas balances 30 years after bog rewetting

    NASA Astrophysics Data System (ADS)

    Vanselow-Algan, M.; Schmidt, S. R.; Greven, M.; Fiencke, C.; Kutzbach, L.; Pfeiffer, E.-M.

    2015-07-01

    Natural peatlands are important carbon sinks and sources of methane (CH4). In contrast, drained peatlands turn from a carbon sink to a carbon source and potentially emit nitrous oxide (N2O). Rewetting of peatlands thus potentially implies climate change mitigation. However, data about the time span that is needed for the re-establishment of the carbon sink function by restoration are scarce. We therefore investigated the annual greenhouse gas (GHG) balances of three differently vegetated sites of a bog ecosystem 30 years after rewetting. All three vegetation communities turned out to be sources of carbon dioxide (CO2) ranging between 0.6 ± 1.43 t CO2 ha-2 yr-1 (Sphagnum-dominated vegetation) and 3.09 ± 3.86 t CO2 ha-2 yr-1 (vegetation dominated by heath). While accounting for the different global warming potential (GWP) of CO2, CH4 and N2O, the annual GHG balance was calculated. Emissions ranged between 25 and 53 t CO2-eq ha-1 yr-1 and were dominated by large emissions of CH4 (22-51 t CO2-eq ha-1 yr-1), with highest rates found at purple moor grass (Molinia caerulea) stands. These are to our knowledge the highest CH4 emissions so far reported for bog ecosystems in temperate Europe. As the restored area was subject to large fluctuations in the water table, we assume that the high CH4 emission rates were caused by a combination of both the temporal inundation of the easily decomposable plant litter of purple moor grass and the plant-mediated transport through its tissues. In addition, as a result of the land use history, mixed soil material due to peat extraction and refilling can serve as an explanation. With regards to the long time span passed since rewetting, we note that the initial increase in CH4 emissions due to rewetting as described in the literature is not inevitably limited to a short-term period.

  8. Holocene methane flux reconstruction from peat macrofossils at Siikaneva bog and fen, Finland

    NASA Astrophysics Data System (ADS)

    Mathijssen, Paul; Korrensalo, Aino; Tuittila, Eeva-Stiina; Väliranta, Minna; Mellais, Annina

    2015-04-01

    Previous studies have shown that a correlation exists between methane flux and peatland plant species abundance. Furthermore, it has been demonstrated that the composition of plant species or functional groups of species can be used as indicator for methane fluxes in peatlands, using weighted averaging. This method has the potential to be very useful in palaeoecological studies of peatlands as well. This method offers the possibility to reconstruct past methane flux based on vegetation remains still present in the peat archive and together with reconstructions of carbon accumulation can give a more complete picture of peatlands' carbon dynamics during the Holocene. Furthermore, effects of changes in hydrology or temperature on methane fluxes can be studied over much longer time scales, compared to what experimental setups allow for. For four peat cores from Siikaneva peatland in southern Finland, we reconstructed the methane flux during the Holocene. Two cores represent a part of the peatland that has currently a fen type vegetation. The other two cores were taken from a part of the peatland that has transformed into a bog, around 3.5 - 5.5 cal. year before present. The development of methane flux during the fen to bog transition is especially of interest. We used vegetation data and methane flux data from chamber measurement from all microtopographies found on Siikaneva and from a few similar peatlands in southern and central Finland as a training set. The plant species were classified into functional groups. Firstly, because it has been shown that usage of functional groups leads to better predictions of methane flux when compared to e.g. species or dominant species. Secondly, the information from the peat cores used as input for the reconstruction is based on progressively decomposed plant remains in subsequent peat layers, for which identification to species level is not always possible (most notably for sedges). We compare the predictive performance of two

  9. Geology and recognition criteria for sandstone uranium deposits in mixed fluvial-shallow marine sedimentary sequences, South Texas. Final report

    SciTech Connect

    Adams, S.S.; Smith, R.B.

    1981-01-01

    Uranium deposits in the South Texas Uranium Region are classical roll-type deposits that formed at the margin of tongues of altered sandstone by the encroachment of oxidizing, uraniferous solutions into reduced aquifers containing pyrite and, in a few cases, carbonaceous plant material. Many of the uranium deposits in South Texas are dissimilar from the roll fronts of the Wyoming basins. The host sands for many of the deposits contain essentially no carbonaceous plant material, only abundant disseminated pyrite. Many of the deposits do not occur at the margin of altered (ferric oxide-bearing) sandstone tongues but rather occur entirely within reduced, pyurite-bearing sandstone. The abundance of pyrite within the sands probably reflects the introduction of H/sub 2/S up along faults from hydrocarbon accumulations at depth. Such introductions before ore formation prepared the sands for roll-front development, whereas post-ore introductions produced re-reduction of portions of the altered tongue, leaving the deposit suspended in reduced sandstone. Evidence from three deposits suggests that ore formation was not accompanied by the introduction of significant amounts of H/sub 2/S.

  10. Fine-scale horizontal and vertical micro-distribution patterns of testate amoebae along a narrow Fen/Bog gradient.

    PubMed

    Jassey, Vincent E J; Chiapusio, Geneviève; Mitchell, Edward A D; Binet, Philippe; Toussaint, Marie-Laure; Gilbert, Daniel

    2011-02-01

    The ecology of peatland testate amoebae is well studied along broad gradient from very wet (pool) to dry (hummock) micro-sites where testate amoebae are often found to respond primarily to the depth to water table (DWT). Much less is known on their responses to finer-scale gradients, and nothing is known of their possible response to phenolic compounds, which play a key role in carbon storage in peatlands. We studied the vertical (0-3, 3-6, and 6-9 cm sampling depths) micro-distribution patterns of testate amoebae in the same microhabitat (Sphagnum fallax lawn) along a narrow ecological gradient between a poor fen with an almost flat and homogeneous Sphagnum carpet (fen) and a "young bog" (bog) with more marked micro-topography and mosaic of poor fen and bog vegetation. We analyzed the relationships between the testate amoeba data and three sets of variables (1) "chemical" (pH, Eh potential, and conductivity), (2) "physical" (water temperature, altitude, i.e., Sphagnum mat micro-topography, and DWT), and (3) phenolic compounds in/from Sphagnum (water-soluble and primarily bound phenolics) as well as the habitat (fen/bog) and the sampling depth. Testate amoeba Shannon H' diversity, equitability J of communities, and total density peaked in lower parts of Sphagnum, but the patterns differed between the fen and bog micro-sites. Redundancy analyses revealed that testate amoeba communities differed significantly in relation to Eh, conductivity, water temperature, altitude, water-soluble phenolics, habitat, and sampling depth, but not to DWT, pH, or primarily bound phenolics. The sensitivity of testate amoebae to weak environmental gradients makes them particularly good integrators of micro-environmental variations and has implications for their use in paleoecology and environmental monitoring. The correlation between testate amoeba communities and the concentration of water-soluble phenolic suggests direct (e.g., physiological) and/or indirect (e.g., through impact on

  11. Characterization of Groundwater Flow Processes in the Cedar Creek Watershed and the Cedarburg Bog in Southeastern Wisconsin

    NASA Astrophysics Data System (ADS)

    Graham, J. P.; Han, W. S.; Feinstein, D.; Hart, D. J.

    2014-12-01

    The purpose of this study is to characterize the geology and groundwater flow of the bog as well as the surrounding area, notably the Cedar Creek Watershed, a HUC (Hydrologic Unit Code) 12 watershed. The watershed is approximately 330 km2, and borders the sub-continental divide separating the Mississippi River Basin from the Great Lakes Basin. The Cedar Creek watershed is composed of mostly agricultural and urban land with a significant stress of groundwater withdrawal for both irrigation and residential use. This watershed has importance due to the contribution to both the Milwaukee River and Lake Michigan, and is integral in the study of regional groundwater flow of Southeastern Wisconsin. Furthermore, the Cedarburg Bog, located in the northeast corner of the Cedar Creek Watershed preserves diverse ecology and is recognized by the U.S. Department of Interior as a National Landmark. Groundwater is the primary driver for the diverse and unique ecology that is contained within the bog. Within the Cedar Creek Watershed, well data and glacial geology maps (Mickelson and Syverson, 1997) were integrated to develop a 3-dimensional subsurface map and watershed-scale groundwater flow model using the LAK3 and the SFR2 package to simulate surface water-aquifer interactions. The model includes 10 zones of the glacial sediments and the weathered and consolidated Silurian Dolomite bedrock. The hydraulic conductivity and storage parameters were calibrated with 203 head targets using universal parameter estimation code (PEST). Then, a series of future climate scenarios, developed by the Wisconsin Initiative on Climate Change Impact, were implemented to the USGS Soil-Water-Balance Code (SWB) to identify variations in recharge. The simulated recharge scenarios were adopted to predict the response of groundwater resources in the watershed and the Cedarburg Bog. Preliminary results produced from the MODFLOW model indicate the bog is acting as a recharge zone under current recharge

  12. Cryptic diversity within morphospecies of testate amoebae (Amoebozoa: Arcellinida) in New England bogs and fens.

    PubMed

    Oliverio, Angela M; Lahr, Daniel J G; Nguyen, Truc; Katz, Laura A

    2014-03-01

    Testate (shelled) amoebae are abundant and diverse in Sphagnum-rich areas of bogs and fens. Test morphology is standardly used to identify morphospecies as tests have varying shapes and compositions (e.g. siliceous, proteinaceous, agglutinated, or even calcareous). The recent application of molecular tools has revealed a greater complexity than morphology suggests, including multiple cryptic species. Here, we assess the biodiversity and relationships among eight morphospecies: Hyalosphenia elegans, Hyalosphenia papilio, Nebela carinata, Nebela flabellulum, Nebela militaris, Nebela tincta, Nebela tubulosa, and Quadrulella symmetrica using small subunit ribosomal DNA (SSU-rDNA). An SSU-rDNA phylogeny including 20 specimens from GenBank and 63 from this study reveals diversity within and among morphospecies and low resolution among some Nebela spp. Previous SSU-rDNA work on a limited sample of these species showed non-monophyly in the genus Hyalosphenia. Our analyses confirm this pattern and further suggest that other Nebela genera and morphospecies are not monophyletic. Moreover, inclusion of up to 24 specimens per species indicates non-monophyly of the morphospecies Hyalosphenia papilio and Hyalosphenia elegans. Our results suggest the morphological plasticity of testate amoebae across evolutionary time scales and that a combination of morphology and molecular analyses is needed to understand the biodiversity of these taxa.

  13. Mycobacterium minnesotense sp. nov., a photochromogenic bacterium isolated from sphagnum peat bogs.

    PubMed

    Hannigan, Geoffrey D; Krivogorsky, Bogdana; Fordice, Daniel; Welch, Jacqueline B; Dahl, John L

    2013-01-01

    Several intermediate-growing, photochromogenic bacteria were isolated from sphagnum peat bogs in northern Minnesota, USA. Acid-fast staining and 16S rRNA gene sequence analysis placed these environmental isolates in the genus Mycobacterium, and colony morphologies and PCR restriction analysis patterns of the isolates were similar. Partial sequences of hsp65 and dnaJ1 from these isolates showed that Mycobacterium arupense ATCC BAA-1242(T) was the closest mycobacterial relative, and common biochemical characteristics and antibiotic susceptibilities existed between the isolates and M. arupense ATCC BAA-1242(T). However, compared to nonchromogenic M. arupense ATCC BAA-1242(T), the environmental isolates were photochromogenic, had a different mycolic acid profile and had reduced cell-surface hydrophobicity in liquid culture. The data reported here support the conclusion that the isolates are representatives of a novel mycobacterial species, for which the name Mycobacterium minnesotense sp. nov. is proposed. The type strain is DL49(T) (=DSM 45633(T) = JCM 17932(T) = NCCB 100399(T)).

  14. Atmospheric methane sources - Alaskan tundra bogs, an alpine fen, and a subarctic boreal marsh

    NASA Technical Reports Server (NTRS)

    Sebacher, D. I.; Harriss, R. C.; Grice, S. S.; Bartlett, K. B.; Sebacher, S. M.

    1986-01-01

    Methane (CH4) flux measurements from Alaska tundra bogs, an alpine fen, and a subarctic boreal marsh were obtained at field sites ranging from Prudhoe Bay on the coast of the Arctic Ocean to the Alaskan Range south of Fairbanks during August 1984. In the tundra, average CH4 emission rates varied from 4.9 mg CH4 per sq m per day (moist tundra) to 119 mg CH4 per sq m per day (waterlogged tundra). Fluxes averaged 40 mg CH4 per sq m per day from wet tussock meadows in the Brooks Range and 289 mg Ch4 per sq m per day from an alpine fen in the Alaskan Range. The boreal marsh had an average CH4 emission rate of 106 mg CH4 per sq m per day. Significant emissions were detected in tundra areas where peat temperatures were as low as 4 C, and permafrost was only 25 cm below the ground surface. Emission rates from the 17 sites sampled were found to be logarithmically related to water levels at the sites. Extrapolation of the data to an estimate of the total annual CH4 emission from all arctic and boreal wetlands suggests that these ecosystems are a major source of atmospheric CH4 and could account for up to 23 percent of global CH4 emissions from wetlands.

  15. Variation in methane production pathways associated with permafrost decomposition in collapse scar bogs of Alberta, Canada

    NASA Astrophysics Data System (ADS)

    Prater, James L.; Chanton, Jeffrey P.; Whiting, Gary J.

    2007-12-01

    Stable isotope analysis was used to determine the distribution of methanogenic pathways at permafrost collapse scar bogs to test the hypothesis that microbial respiration and methane production are stimulated by the input of organic matter associated with permafrost degradation and collapse. An alternative hypothesis is that recently assimilated carbon produced by the fen-like vegetation (Carex, Eriophorum) growing in open water moats formed by the collapsing edge of these features stimulates microbial respiration. We found that CO2 reduction was the dominant pathway for methanogenesis within the Sphagnum areas that dominate the surface cover of these features, but relatively more acetate fermentation occurred near collapse scar moats. Methane emission and net CO2 uptake were correlated. Both were elevated in collapse scar moats and then decreased along a transect from the moats toward the center Sphagnum-dominated areas. There also appeared to be a shift toward relatively more acetate fermentation in deeper samples associated with increasing cation (calcium and magnesium) concentrations. Our results indicate that organic inputs from permafrost degradation alone do not appear to stimulate acetate fermentation. Permafrost decomposition provides conditions along the collapsing edge that are conducive to colonization by fen-like vegetation that stimulates acetate fermentation and increases methane production and emission rates.

  16. Superfund record of decision (EPA Region 2): Burnt Fly Bog, Marlboro Township, NJ, September 30, 1998

    SciTech Connect

    1999-03-01

    This decision document presents the selected remedial action for the Westerly Wetlands, Northerly Wetlands, and Tar Patch Area at the Burnt Fly Bog Superfund Site. It addresses contaminated soil present on the three remaining contaminated areas on the Site, including the Westerly Wetlands, Northerly Wetlands, and Tar Patch Area. The major components of the selected remedy include: Excavation and off-site disposal of contaminated soil from the Northerly Wetlands; Excavation and off-site disposal of contaminated soil from the Tar Patch Area; Backfilling the excavated area in the Northerly Wetland and reestablishing wetlands; Backfilling the excavated area in the Tar Patch Area and creating wetlands; Provision of additional security fencing around the Westerly Wetlands, and the recording of a Deed Notice for the Westerly Wetlands, Northerly Wetlands, and Tar Patch Area; Monitoring of surface water and sediment in the Westerly Wetlands, surface water and sediment in the existing sedimentation basin located in the Downstream Area, and surface water, sediment and, if necessary, biota in Burnt Fly Brook; and Biological sampling in the Westerly Wetlands.

  17. Ecosystem Phenology from Eddy-covariance Measurements: Spring Photosynthesis in a Cool Temperate Bog

    NASA Astrophysics Data System (ADS)

    Lafleur, P.; Moore, T. R.; Poon, D.; Seaquist, J.

    2005-12-01

    The onset and increase of spring photosynthetic flux of carbon dioxide is an important attribute of the carbon budget of northern ecosystems and we used eddy-covariance measurements from March to May over 5 years at the Mer Bleue ombrotrophic bog to establish the important controls. The onset of ecosystem photosynthesis (day-of-year from 86 to 101) was associated with the disappearance on the snow cover and there is evidence that photosynthesis can continue after a thin new snowfall. The growth of photosynthesis during the spring period was partially associated with light (daily photosynthetically active radiation) but primarily with temperature, with the strongest correlation being observed with peat temperature at a depth of 5 and 10 cm, except in one year in which there was a long snow cover. The vegetation comprises mosses, which are able to photosynthesize very early, evergreen shrubs, which appear dependent on soil warming, and deciduous shrubs, which leaf-out only in late spring. We observed changes in shrub leaf colour from brown to green and concomitant increases in foliar nitrogen and chlorophyll concentrations during the spring in this "evergreen" system. We analyzed MODIS images for periods of overlap of tower and satellite data and found a generally strong correlation, though the infrequent satellite measurements were unable to pick out the onset and timing of rapid growth of photosynthesis in this ecosystem.

  18. Linking glacial deposits and lake sediments for paleoclimate studies in the Northern Romanian Carpathians

    NASA Astrophysics Data System (ADS)

    Zamosteanu, Andrei; Mindrescu, Marcel; Anselmetti, Flavio; Akçar, Naki; Lowick, Sally E.; Vogel, Hendrik

    2015-04-01

    Timing and extent of glaciations in the Carpathian mountains are still controversely discussed, mostly due to the lack of well dated geomorphological and geochronological studies. We present the preliminary results of geomorphological and sedimentological analyses of glacial and lacustrine deposits in Bistricioara Valley located in the Rodna Mountains (Northern Romanian Carpathians). Most of the glacial deposits in the Romanian Carpathians, such as moraines, typically occur above 1600 m a.s.l. marking the maximum lowering of past glaciations. Most of the glacial lakes occur between 1800 and 2000 m a.s.l. Field surveys included mapping of moraines and erratic boulders using detailed topographical maps and aerial photos. A Digital Elevation Model (DEM) was derived using GIS (ArcMap 10.1) from 1:25000 topographic maps, which was further completed by field survey data. The resulting geomorphological map shows a series of moraines, which indicate the occurrence of several glacial phases in the study area. Sediment samples were collected from a peat bog (1630 m a.s.l.) dammed by a large lateral moraine within Bistricioara Mare, one of the largest glacial cirques in the Romanian Carpathians. A Russian corer was used to extract the sediment profile from the peat bog (approx. 5 m long sediment core). A X-ray computed tomography (CT) system was employed for the study of sedimentary and deformation structures and X-ray fluorescence spectroscopy (XRF) for multi-element analysis at high resolution. Glacial deposits from the lateral moraine in front of the peat bog were also sampled, as well as from the frontal moraines, upstream and downstream of the peat bog. This set of samples from multiple archives allows to link and merge the chronologies and the paleoenvironmental records of glacial deposits and lake sediments. Moreover, we employed cosmogenic nuclide dating for the reconstruction of glacial stages and their paleoclimatic implications during deglaciation in this area of

  19. Vegetation drives belowground biogeochemical gradients and C accumulation in an ombrotrophic bog

    NASA Astrophysics Data System (ADS)

    Knorr, Klaus-Holger; Galka, Mariusz; Borken, Werner

    2016-04-01

    Peat decomposition and C accumulation is determined by hydrology and climate and by concomitant changes in vegetation and changes in the quality of carbon inputs. Especially changes from moss dominated to vascular plant dominated vegetation affect belowground biogeochemistry and decomposition, as Sphagnum mosses provide refractory, nutrient poor litter, while vascular plants produce more labile litter and may have aerenchymatic rooting systems. In-site variability in moisture and vegetation, e.g. hummock-hollow structures, lawns, and medium scale surface topography, could thus cause large differences in decomposition and C accumulation within a site. In order to understand within-site variability and to see how C accumulation, common decomposition indices, and major biogeochemical parameters in the pore waters are affected by site specific conditions and vegetation, we investigated a moisture-vegetation gradient along a 800 m transect in an oceanic, ombrotrophic bog in Southern Patagonia. Along the transect, conditions changed from wet, Sphagnum dominated (S. magellanicum), to intermediate drier and wetter with Sphagnum/shrubs mixtures, sedges and rushes to more wind exposed, dominated by cushion plants (mainly Astelia pumila). We hypothesized that under arenchymatic vascular plants, decomposition is enhanced and C accumulation is decreased. Vegetation development was elucidated by plant macrofossils and carbon accumulation was attributed to the respective vegetation. The transect demonstrated a high variability of depth records within the bog. At the two most contrasting sites, the uppermost 1 meter persistently dominated by either Sphagnum magellanicum or Astelia pumila had accumulated over 2400 or 4200 years, respectively. Accordingly, the peat under cushion plants was much more decomposed, with C/N ratios of 20-50 compared to C/N ratios of 40-80 under Sphagnum patches. Mixed sites in between had C/N ratios of 30-90, depending on plant community, and

  20. Impact of long term wetting on pore water chemistry in a peat bog in Ontario, Canada

    NASA Astrophysics Data System (ADS)

    Schaper, Jonas; Blodau, Christian; Holger Knorr, Klaus

    2013-04-01

    Peatlands of the northern hemisphere store a remarkable amount of carbon but also contribute to global methane emissions. As large areas in the boreal and subarctic zone are considered to undergo significant climate change it is necessary to understand how these ecosystems react to altered environmental conditions. Since not only temperatures but also precipitation is likely to increase in these regions, it is of particular interest to understand the impact of raised water tables and changing local hydrological flow patterns on peatlands' carbon cycle. We chose a pristine bog that was partly flooded by a reservoir lake created 60 years ago in Ontario, Canada. Water management in the reservoir resulted in seasonal flooding, shifting hydrological flow patterns and vegetation gradients. The impact of partial flooding on pore water chemistry and DIC and CH4 concentrations were studied within surface peat layers. Samples were taken with pore water peepers along the vegetation- and flooding gradient. Turnover rates of DIC and methane were calculated from obtained concentration profiles and peat porosity under the assumption that transport is dominated by diffusion. Values of pH changed remarkably from 4 within the undisturbed bog part to almost 8 at the lake shore. Ca2+ and Mg2+ were the only ions that showed significant distribution patterns with readily increasing concentrations towards the lake water body. CH4 and DIC concentrations also increased towards the lake and peaked in around 100 cm depth right at the shore with maximum concentrations being 2766 μmol L-1 for CH4 and 7543 μmol L-1 for DIC, respectively. Turnover rates also increased towards the shore albeit some uncertainty lies in this finding as steady state condition required for calculations were probably not established and transport was not only dominated by diffusion. Maximum CH4 production rates were modeled to be 36 nmol cm-3 d-1 and maximum DIC production was calculated to 64 nmol cm-3 d-1. Ca2

  1. Carbon cycling responses to a water table drawdown and decadal vegetation changes in a bog

    NASA Astrophysics Data System (ADS)

    Talbot, J.; Roulet, N. T.

    2009-12-01

    The quantity of carbon stored in peat depends on the imbalance between production and decomposition of organic matter. This imbalance is mainly controlled by the wetness of the peatland, usually described by the water table depth. However, long-term processes resulting from hydrological changes, such as vegetation succession, also play a major role in the biogeochemistry of peatlands. Previous studies have looked at the impact of a water table lowering on carbon fluxes in different types of peatlands. However, most of these studies were conducted within a time frame that did not allow the examination of vegetation changes due to the water table lowering. We conducted a study along a drainage gradient resulting from the digging of a drainage ditch 85 years ago in a portion of the Mer Bleue bog, located near Ottawa, Canada. According to water table reconstructions based on testate amoeba, the drainage dropped the water table by approximately 18 cm. On the upslope side of the ditch, the water table partly recovered and the vegetation changed only marginally. However, on the downslope side of the ditch, the water table stayed persistently lower and trees established (Larix and Betula). The importance of Sphagnum decreased with a lower water table, and evergreen shrubs were replaced by deciduous shrubs. The water table drop and subsequent vegetation changes had combined and individual effects on the carbon functioning of the peatland. Methane fluxes decreased because of the water table lowering, but were not affected by vegetation changes, whereas respiration and net ecosystem productivity were affected by both. The carbon storage of the system increased because of an increase in plant biomass, but the long-term carbon storage as peat decreased. The inclusion of the feedback effect that vegetation has on the carbon functioning of a peatland when a disturbance occurs is crucial to simulate the long-term carbon balance of this ecosystem.

  2. Bioavailability of inorganic arsenic from bog ore-containing soil in the dog.

    PubMed Central

    Groen, K; Vaessen, H A; Kliest, J J; de Boer, J L; van Ooik, T; Timmerman, A; Vlug, R F

    1994-01-01

    In some parts of The Netherlands, bog ore-containing soils predominate, which have natural arsenic levels that exceed, by a factor of 10, existing standards for maximum allowable levels of inorganic arsenic in soil. These standards are based on the assumption that in humans the bioavailability of arsenic from ingested soil is equal to that from an aqueous solution. In view of the regulatory problem that the arsenic levels of these soils present, we questioned the validity of this assumption. To obtain a more realistic estimate, the bioavailability of inorganic arsenic from soil in a suitable animal model was studied. In this report, a study performed in six dogs in a two-way cross-over design is presented. The dogs received orally, in random order, arsenic both as an intravenous solution and as arsenic-containing soil. During a 120-hr period after administration urine was collected in 24-hr fractions. Levels of arsenic were determined using a method of wet digestion, isolation and complexation of arsine, followed by molecule absorption spectrometry. Within 120 hr after intravenous administration, 88 +/- 16% of the dose was excreted renally. After oral administration of arsenic-containing soil, only 7.0 +/- 1.5% was excreted renally. From the urinary excretion data for these two routes of administration, the calculated bioavailability of inorganic arsenic from soil was 8.3 +/- 2.0%. The results from this study demonstrate the need to reconsider the present risk assessment for arsenic in soil. Images Figure 1. Figure 2. PMID:8033848

  3. Influence of water table on carbon dioxide, carbon monoxide, and methane fluxes from taiga bog microcosms

    SciTech Connect

    Funk, D.W.; Pullmann, E.R.; Peterson, K.M.

    1994-09-01

    Hydrological changes, particularly alterations in water table level, may largely overshadow the more direct effects of global temperature increase upon carbon cycling in arctic and subarctic wetlands. Frozen cores (n=40) of intact soils and vegetation were collected from a bog near Fairbanks, Alaska, and fluxes of CO{sub 2}, CH{sub 4}, and Co in response to water table variation were studied under controlled conditions in the Duke University phytotron. Core microcosms thawed to a 20-cm depth over 30 days under a 20 hour photoperiod with a day/night temperature regime of 20/10{degrees}C. After 30 days the water table in 20 microcosms was decreased from the soil surface to -15 cm and maintained at the soil surface in 20 control cores. Outward fluxes of CO{sub 2} (9-16 g m{sup -2}d{sup -1}) and CO (3-4 mg m{sup -2}d{sup -1}) were greatest during early thaw and decreased to near zero for both gases before the water table treatment started. Lower water table tripled CO{sub 2} flux to the atmosphere when compared with control cores. Carbon monoxide was emitted at low rates from high water table cores and consumed by low water table cores. Methane fluxes were low (<1 mg m{sup -2}d{sup -1}) in all cores during thaw. High water table cores increased CH{sub 4} flux to 8-9 mg m{sup -2}d{sup -1} over 70 days and remained high relative to the low water table cores (<0.74 mg m{sup -2}d{sup -1}). Although drying of wetland taiga soils may decrease CH{sub 4} emissions to the atmosphere, the associated increase in CO{sub 2} due to aerobic respiration will likely increase the global warming potential of gas emissions from these soils. 43 refs., 4 figs.

  4. Characterization of the efficiency of sedimentation basins downstream of harvested peat bogs

    NASA Astrophysics Data System (ADS)

    Samson-Do, Myriam; St-Hilaire, André

    2015-04-01

    Peat harvesting is a very lucrative industry in the provinces of Quebec and New-Brunswick (Canada). Peat enters in many potting mix used for horticulture. However, harvesting this resource has some impacts on the environment. First, industries need to drain the peat bog to dry the superficial layer. Then, it is harvested with industrial vacuums and the underlying layer is allowed to dry. The drained water is laden with suspended sediments (mostly organic peat fibers) that may affect biota of the stream where it is discharged. To counter the problem, this water does not go directly on the stream but first flows through a sedimentation basin, built to reduce suspended sediment loads. This work focuses on characterizing and eventually modeling the efficiency of those sedimentation basins. Seven basins were studied in Rivière-du-Loup, St-Valère and Escoumins (Quebec, Canada). They each have a different ratio basin area/drained area (4.7 10-4 to 20.3 10-4). To continuously monitor the sediment loads (calculated from sediment concentrations and discharge) entering and leaving basins, a nephelometer and a level logger were installed in the water column upstream and downstream of sedimentation basins. Their trapping efficiency was measured during the ice-free period (May to October) and for each significant rain event, since it is known that the rain and subsequent runoff induce most of the peat transport in and out of the basin. Results show that the event efficiency decreases as the basin is filled up with trapped sediments. For one basin, the efficiency was 85August. Trapping efficiency can be used as a tool to estimate basin dimensions. This has been done for municipal sedimentation ponds that trap minerals and will be adapted to the current context, where the dominant sediment is organic.

  5. Paenibacillus frigoriresistens sp. nov., a novel psychrotroph isolated from a peat bog in Heilongjiang, Northern China.

    PubMed

    Ming, Hong; Nie, Guo-Xing; Jiang, Hong-Chen; Yu, Tian-Tian; Zhou, En-Min; Feng, Hui-Gen; Tang, Shu-Kun; Li, Wen-Jun

    2012-08-01

    A novel cold-resistant bacterium, designated YIM 016(T), was isolated from a peat bog sample collected from Mohe County, Heilongjiang Province, Northern China and its taxonomic position was investigated using a polyphasic approach. The strain was Gram-positive, aerobic, endospore-forming, motile and rod-shaped. Phylogenetic analyses based on the 16S rRNA gene sequence clearly revealed that strain YIM 016(T) is a member of the genus Paenibacillus. The strain is closely related to Paenibacillus alginolyticus DSM 5050(T), Paenibacillus chondroitinus DSM 5051(T) and Paenibacillus pocheonensis Gsoil 1138(T) with similarities of 99.0 %, 97.0 % and 96.3 %, respectively. Meanwhile, the low DNA-DNA relatedness levels between strain YIM 016(T) and its closely related phylogenetic neighbours demonstrated that this isolate represents a new genomic species in the genus Paenibacillus. Phenotypic and chemotaxonomic tests showed that growth of strain YIM 016(T) occurred at 4-37 °C, pH 6.0-8.0 and with a NaCl tolerance up to 0.5 % (w/v). The peptidoglycan contained meso-diaminopimelic acid, alanine and glutamic acid. The whole-cell hydrolysates mainly contained glucose, galactose and ribose. The predominant menaquinone was MK-7 and the major fatty acids were anteiso-C(15:0) and iso-C(16:0). The DNA G+C content of strain YIM 016(T) was 51.7 mol %. On the basis of phylogenetic, phenotypic and chemotaxonomic characteristics, strain YIM 016(T) could be clearly distinguished from other species of the genus Paenibacillus. It is therefore concluded that strain YIM 016(T) represents a novel species in the genus Paenibacillus, for which the name Paenibacillus frigoriresistens sp. nov. is proposed. The type strain is YIM 016(T) (= CCTCC AB 2011150(T) = JCM 18141(T)).

  6. [Spatial structure of communities of heterotrophic flagellates from a sphagnum bog].

    PubMed

    Tikhonenkov, D V; Mazeĭ, Iu A

    2009-01-01

    Spatial distribution pattern of heterotrophic flagellates within a macroscopically homogenous sphagnum parcel of a transitional bog in the southern taiga was studied. Under investigation was horizontal pattern at different scales (1 cm, 10 cm, 1 m, 10 m) and the vertical heterogeneity of the community in the sphagnum quagmire. 105 species and forms of heterotrophic flagellates were revealed. Predominating were euglenids, less abundant are kynetoplastids and cercomonads. The most numerous appeared to be Cryptomonas sp., Heteromita minima, Goniomonas truncata, Protaspis simplex, Bodo designis, B. saltans, Phyllomitus apiculatus, Paraphysomonas sp., Petalomonas minuta. More abundant species were characterized by less patchy distribution than less abundant. At a smaller scale, the community was formed by the species with different degree of patchiness while at larger scales, all the species possess nearly the same distribution pattern. The same number of samples of equal sizes revealed nearly the same species numbers independently of distances between the sample sites, as the samples at each scale differ from each other nearly at the same magnitude. An averaged size of the species aggregations in the community is as large as several centimeters. Such a scale is probably a characteristic size (minimum area) of the community of the sphagnum dwelling heterotrophic flagellates. Rather low environmental heterogeneity within the sphagnum quagmire leads to significant homogeneity of the community at larger scales. Vertical differentiation of the heterotrophic flagellate community within that quagmire appeared to be very unstable with the time. The same species are characterized by different preferences to the depths at different spatial-temporal loci. Specific vertical distributions and community patterns are formed under different local conditions.

  7. Atmospheric Deposition of Indium in the Northeastern United States: Flux and Historical Trends.

    PubMed

    White, Sarah Jane O; Keach, Carrie; Hemond, Harold F

    2015-11-01

    The metal indium is an example of an increasingly important material used in electronics and new energy technologies, whose environmental behavior and toxicity are poorly understood despite increasing evidence of detrimental health impacts and human-induced releases to the environment. In the present work, the history of indium deposition from the atmosphere is reconstructed from its depositional record in an ombrotrophic bog in Massachusetts. A novel freeze-coring technique is used to overcome coring difficulties posed by woody roots and peat compressibility, enabling retrieval of relatively undisturbed peat cores dating back more than a century. Results indicate that long-range atmospheric transport is a significant pathway for the transport of indium, with peak concentrations of 69 ppb and peak fluxes of 1.9 ng/cm2/yr. Atmospheric deposition to the bog began increasing in the late 1800s/early 1900s, and peaked in the early 1970s. A comparison of deposition data with industrial production and emissions estimates suggests that both coal combustion and the smelting of lead, zinc, copper, and tin sulfides are sources of indium to the atmosphere in this region. Deposition appears to have decreased considerably since the 1970s, potentially a visible effect of particulate emissions controls instated in North America during that decade.

  8. How will the semi-natural vegetation of the UK have changed by 2030 given likely changes in nitrogen deposition?

    PubMed

    Stevens, Carly J; Payne, Richard J; Kimberley, Adam; Smart, Simon M

    2016-01-01

    Nitrogen deposition is known to have major impacts on contemporary ecosystems but few studies have addressed how these impacts will develop over coming decades. We consider likely changes to British semi-natural vegetation up to the year 2030 both qualitatively, based on knowledge of species responses from experimental and gradient studies, and quantitatively, based on modelling of species relationships in national monitoring data. We used historical N deposition trends and national predictions of changing deposition to calculate cumulative deposition from 1900 to 2030. Data from the Countryside Survey (1978, 1990 and 1998) was used to parameterise models relating cumulative N deposition to Ellenberg N which were then applied to expected future deposition trends. Changes to habitat suitability for key species of grassland, heathland and bog, and broadleaved woodland to 2030 were predicted using the MultiMOVE model. In UK woodlands by 2030 there is likely to be reduced occurrence of lichens, increased grass cover and a shift towards more nitrophilic vascular plant species. In grasslands we expect changing species composition with reduced occurrence of terricolous lichens and, at least in acid grasslands, reduced species richness. In heaths and bogs we project overall reductions in species richness with decreased occurrence of terricolous lichens and some bryophytes, reduced cover of dwarf shrubs and small increases in grasses. Our study clearly suggests that changes in vegetation due to nitrogen deposition are likely to continue through coming decades.

  9. Modeling CH4 and CO2 cycling using porewater stable isotopes in a thermokarst bog, interior Alaska

    NASA Astrophysics Data System (ADS)

    Neumann, R. B.; Blazewicz, S.; Waldrop, M. P.

    2014-12-01

    Methane emitted from wetlands represents the end product of various microbial processes operating within anaerobic wetland soils. Determining the rate at which these microbial reactions occur is challenging, making it difficult to gain a mechanistic understanding of the factors and conditions that influence microbial rates and ultimately methane emissions. One approach for estimating in-situ reaction rates involves tracking the time evolution of porewater concentrations and stable carbon isotopes of CH4 and CO2. Microbes preferentially use isotopically light carbon substrates, which causes the carbon product pool to become isotopically lighter and the carbon substrate pool become isotopically heavier. Different microbial biochemical pathways fractionate carbon to different extents, allowing for differentiation between microbial reactions. This is a powerful approach to estimate in-situ rates, but, as we show in our presentation, it is possible for different combinations of reaction rates to provide equally good fits to the evolution of these data. The solution is non-unique and depends on the set of considered reactions. We used two different reaction network models on a set of porewater data collected from a thermokarst bog at the Alaska Peatland Experiment (APEX) outside of Fairbanks, AK to estimate in-situ microbial reaction rates during the summer season. Both models included methane production, methane oxidation and fermentation/respiration, but only one model included homoacetogenesis. We found that both reaction networks explained the evolution of dissolved gas concentrations and stable carbon isotope data, but predicted rates that differed from each other by up to a factor of six. The methane production rates estimated by the model that included homoacetogenesis aligned better with measured rates of methane emission. Despite differences in the magnitude of modeled rates, results from the two models told a similar story about the spatial and temporal

  10. Response of Sphagnum fuscum to Nitrogen Deposition: A Case Study of Ombrogenous Peatlands in Alberta, Canada

    USGS Publications Warehouse

    Vitt, D.H.; Wieder, K.; Halsey, L.A.; Turetsky, M.

    2003-01-01

    Peatlands cover about 30% of northeastern Alberta and are ecosystems that are sensitive to nitrogen deposition. In polluted areas of the UK, high atmospheric N deposition (as a component of acid deposition) has been considered among the causes of Sphagnum decline in bogs (ombrogenous peatlands). In relatively unpolluted areas of western Canada and northern Sweden, short-term experimental studies have shown that Sphagnum responds quickly to nutrient loading, with uptake and retention of nitrogen and increased production. Here we examine the response of Sphagnum fuscum to enhanced nitrogen deposition generated during 34 years of oil sands mining through the determination of net primary production (NPP) and nitrogen concentrations in the upper peat column. We chose six continental bogs receiving differing atmospheric nitrogen loads (modeled using a CALPUFF 2D dispersion model). Sphagnum fuscum net primary production (NPP) at the high deposition site (Steepbank - mean of 600 g/m2; median of 486 g/m2) was over three times as high than at five other sites with lower N deposition. Additionally, production of S. fuscum may be influenced to some extent by distance of the moss surface from the water table. Across all sites, peat nitrogen concentrations are highest at the surface, decreasing in the top 3 cm with no significant change with increasing depth. We conclude that elevated N deposition at the Steepbank site has enhanced Sphagnum production. Increased N concentrations are evident only in the top 1-cm of the peat profile. Thus, 34 years after mine startup, increased N-deposition has increased net primary production of Sphagnum fuscum without causing elevated levels of nitrogen in the organic matter profile. A response to N-stress for Sphagnum fuscum is proposed at 14-34 kg ha-1 yr-1. A review of N-deposition values reveals a critical N-deposition value of between 14.8 and 15.7 kg ha -1 yr-1 for NPP of Sphagnum species.

  11. Concentration and grain-size distribution of aeolian sands in peat bogs as an indicator of past storminess in coastal areas of Estonia

    NASA Astrophysics Data System (ADS)

    Vandel, Egert; Vaasma, Tiit; Tõnisson, Hannes; Sugita, Shinya; Vilumaa, Kadri; Anderson, Agnes; Terasmaa, Jaanus; Kangur, Mihkel; Pensa, Margus; Küttim, Martin; Umbleja, Liisa; Puusepp, Liisa

    2016-04-01

    Storminess in the Baltic Sea region has significantly increased over the last 50 years. As we do not have meteorological data beyond 20th century, therefore the long-term changes in storminess (e.g., frequency and magnitude of the storms) and its impact on the coastal evolution are mostly unknown. This study aims to reconstruct the extreme storm events along the coast of Estonia in late Holocene, inferred from changes in grain-size distribution and concentration of aeolian sands preserved in peat deposits. Four cores in total were collected from bogs of coastal Estonia; three from west Estonian archipelago (Hiiumaa Island and Saaremaa Island); one from the northern coast of the mainland (Juminda Peninsula). Core from Saaremaa (166 cm) covers the last 2700 years, cores from Hiiumaa (171 cm and 330 cm) cover ca 4000 years, and core from Juminda (465 cm) covers ca 8500 years. All AMS dates (77) are converted to cal yrs BP. Analyses of LOI and grain size are carried out at every centimetre in order to obtain data for mineral matter content and concentration of sand particles. The Juminda core shows a consistently low content of mineral matter (LOI < 2%) without clear peaks over the last 8000 years. The LOI results at both Hiiumaa sites show that mineral matter content gradually decreases from 4000 to 1500 cal yrs BP and then becomes the lowest in the period of 1500-1000 cal yrs BP; since then, it becomes higher (up to 10%) with fluctuations and has a clear peak around 700 cal yrs BP. At Saaremaa, the overall trend of mineral matter content is similar to that at the Hiiumaa sites: gradual decline from 2700 to 1500 cal yrs BP, lowest in 1500-1000 cal yrs BP, and relatively high over the last millennium. Concentration of mineral particles reveal clear peaks of aeolian sands at each site. At northern Hiiumaa, concentration has peaks around 3500, 3000 and 2500 cal yrs BP and is relatively high over the last 700 years. At Saaremaa, concentration has peaked at 2100, 1600 and

  12. Exploration systems approach to the Spokane Mountain area uranium deposits, Northeastern Washington

    SciTech Connect

    Babcock, L.; Beck, P.; Farley, W.; Lechler, P.; Lindgren, J.; Miller, D.; Pigott, J.; Sayala, D.; Trujillo, R.; Wayland, T.

    1981-07-01

    Within the gross context of economic exploration techniques developed through case studies of known mineralization, this report of research into the Spokane Mountain uranium deposit integrates the results of numerous field surveys and the application of proven scientific methods with the effects of all tasks weighed against those of similar activities and the costs of alternative methods. An exploration systems approach to the problem required a synthesis of information derived mainly from a small mining district in Stevens County, Washington. Data were obtained by utilizing sources of information available to the mineral industry and state-of-the-art uranim exploration techniques, including geological, geophysical, geochemical, and emanometric procedures. The Spokane Mountain mineralization exemplifies classical conditions of uranium deposits that form in the contact zone developed between metasediments and uraniferous intrusive rocks. Geological studies for this report include assessments of subsurface conditions; interpretations of detailed petrographic examinations that emphasize depositional environments, metamorphic effects, alteration, paragenesis, mineralogy, and origin; and overviews of regional stratigraphy, structure, metamorphism, plutonium, and metallogeny. Elements and minerals associated with uranium were detected along the contact zone, Midnite Trend, using geochemical techniques applied to both soils and stream surveys. The coincidence of molybdenum and uranium in the sediments and water of streams in the Spokane Mountain area indicates a nearby source of uranium. The abundance of multielements such as U, As, and F in the soils, checked at various densities and scales, are indicators of uranium mineralization; also, two targets with uranium potential apparently exist in areas peripheral to Spokane Mountain.

  13. Carbon and Nitrogen Isotope Variation in Sphagnum from Peat Bogs in the Midwestern Us: Implications for Holocene Climate Reconstruction

    NASA Astrophysics Data System (ADS)

    Wong, D.; Paytan, A.; Jackson, S. T.

    2009-12-01

    A peat core taken from near the center of Minden Bog in Michigan, representing about 3500 years of accumulation was previously analyzed for plant macrofossils, colorimetric humification, and testate amoebae to yield three independent climate proxies. The data show the site to be sensitive to bog water table fluctuations and suggest that this may be related to regional climatic changes. We analyzed the carbon and nitrogen isotopes and the carbon-nitrogen ratios in the bulk peat samples and determined that the changes in these isotopes and ratios can be attributed to one or more of the following: (1) changes in the relative abundance of vegetation taxa in the site, (2) changes in the metabolism that impact isotope ratios in the vegetation contributing to the bulk organic, and (3) selective preservation and regeneration of specific organic compounds within the bulk organic matter. We analyzed the carbon and nitrogen isotopes and the carbon-nitrogen ratios in a specific taxum, Sphagnum, to differentiate between these mechanisms and relate the record to water level and climate in the region.

  14. Contrasting wetland CH4 emission responses to simulated glacial atmospheric CO2 in temperate bogs and fens.

    PubMed

    Boardman, Carl P; Gauci, Vincent; Watson, Jonathan S; Blake, Stephen; Beerling, David J

    2011-12-01

    Wetlands were the largest source of atmospheric methane (CH(4) ) during the Last Glacial Maximum (LGM), but the sensitivity of this source to exceptionally low atmospheric CO(2) concentration ([CO(2) ]) at the time has not been examined experimentally. We tested the hypothesis that LGM atmospheric [CO(2) ] reduced CH(4) emissions as a consequence of decreased photosynthate allocation to the rhizosphere. We exposed minerotrophic fen and ombrotrophic bog peatland mesocosms to simulated LGM (c. 200 ppm) or ambient (c. 400 ppm) [CO(2) ] over 21 months (n = 8 per treatment) and measured gaseous CH(4) flux, pore water dissolved CH(4) and volatile fatty acid (VFA; an indicator of plant carbon supply to the rhizosphere) concentrations. Cumulative CH(4) flux from fen mesocosms was suppressed by 29% (P < 0.05) and rhizosphere pore water [CH(4) ] by c. 50% (P < 0.01) in the LGM [CO(2) ], variables that remained unaffected in bog mesocosms. VFA analysis indicated that changes in plant root exudates were not the driving mechanism behind these results. Our data suggest that the LGM [CO(2) ] suppression of wetland CH(4) emissions is contingent on trophic status. The heterogeneous response may be attributable to differences in species assemblage that influence the dominant CH(4) production pathway, rhizosphere supplemented photosynthesis and CH(4) oxidation.

  15. Holocene vegetation and climate change recorded in alpine bog sediments from the Borreguiles de la Virgen, Sierra Nevada, southern Spain

    NASA Astrophysics Data System (ADS)

    Jiménez-Moreno, Gonzalo; Anderson, R. Scott

    2012-01-01

    High-resolution pollen and magnetic susceptibility (MS) analyses have been carried out on a sediment core taken from a high-elevation alpine bog area located in Sierra Nevada, southern Spain. The earliest part of the record, from 8200 to about 7000 cal yr BP, is characterized by the highest abundance of arboreal pollen and Pediastrum, indicating the warmest and wettest conditions in the area at that time. The pollen record shows a progressive aridification since 7000 cal yr BP that occurred in two steps, first shown by a decrease in Pinus, replaced by Poaceae from 7000 to 4600 cal yr BP and then by Cyperaceae, Artemisia and Amaranthaceae from 4600 to 1200 cal yr BP. Pediastrum also decreased progressively and totally disappeared at ca. 3000 yr ago. The progressive aridification is punctuated by periodically enhanced drought at ca. 6500, 5200 and 4000 cal yr BP that coincide in timing and duration with well-known dry events in the Mediterranean and other areas. Since 1200 cal yr BP, several changes are observed in the vegetation that probably indicate the high-impact of humans in the Sierra Nevada, with pasturing leading to nutrient enrichment and eutrophication of the bog, Pinus reforestation and Olea cultivation at lower elevations.

  16. Contrasting species-environment relationships in communities of testate amoebae, bryophytes and vascular plants along the fen-bog gradient.

    PubMed

    Lamentowicz, Mariusz; Lamentowicz, Lukasz; van der Knaap, Willem O; Gabka, Maciej; Mitchell, Edward A D

    2010-04-01

    We studied the vegetation, testate amoebae and abiotic variables (depth of the water table, pH, electrical conductivity, Ca and Mg concentrations of water extracted from mosses) along the bog to extremely rich fen gradient in sub-alpine peatlands of the Upper Engadine (Swiss Alps). Testate amoeba diversity was correlated to that of mosses but not of vascular plants. Diversity peaked in rich fen for testate amoebae and in extremely rich fen for mosses, while for testate amoebae and mosses it was lowest in bog but for vascular plants in extremely rich fen. Multiple factor and redundancy analyses (RDA) revealed a stronger correlation of testate amoebae than of vegetation to water table and hydrochemical variables and relatively strong correlation between testate amoeba and moss community data. In RDA, hydrochemical variables explained a higher proportion of the testate amoeba and moss data than water table depth. Abiotic variables explained a higher percentage of the species data for testate amoebae (30.3% or 19.5% for binary data) than for mosses (13.4%) and vascular plants (10%). These results show that (1) vascular plant, moss and testate amoeba communities respond differently to ecological gradients in peatlands and (2) testate amoebae are more strongly related than vascular plants to the abiotic factors at the mire surface. These differences are related to vertical trophic gradients and associated niche differentiation.

  17. Sphagnum mosses from 21 ombrotrophic bogs in the athabasca bituminous sands region show no significant atmospheric contamination of "heavy metals".

    PubMed

    Shotyk, William; Belland, Rene; Duke, John; Kempter, Heike; Krachler, Michael; Noernberg, Tommy; Pelletier, Rick; Vile, Melanie A; Wieder, Kelman; Zaccone, Claudio; Zhang, Shuangquan

    2014-11-01

    Sphagnum moss was collected from 21 ombrotrophic (rain-fed) peat bogs surrounding open pit mines and upgrading facilities of Athabasca bituminous sands in Alberta (AB). In comparison to contemporary Sphagnum moss from four bogs in rural locations of southern Germany (DE), the AB mosses yielded lower concentrations of Ag, Cd, Ni, Pb, Sb, and Tl, similar concentrations of Mo, but greater concentrations of Ba, Th, and V. Except for V, in comparison to the "cleanest", ancient peat samples ever tested from the northern hemisphere (ca. 6000-9000 years old), the concentrations of each of these metals in the AB mosses are within a factor of 3 of "natural, background" values. The concentrations of "heavy metals" in the mosses, however, are proportional to the concentration of Th (a conservative, lithophile element) and, therefore, contributed to the plants primarily in the form of mineral dust particles. Vanadium, the single most abundant trace metal in bitumen, is the only anomaly: in the AB mosses, V exceeds that of ancient peat by a factor of 6; it is therefore enriched in the mosses, relative to Th, by a factor of 2. In comparison to the surface layer of peat cores collected in recent years from across Canada, from British Columbia to New Brunswick, the Pb concentrations in the mosses from AB are far lower.

  18. Seasonal Oxygen Dynamics in a Thermokarst Bog in Interior Alaska: Implications for Rates of Methane Oxidation

    NASA Astrophysics Data System (ADS)

    Neumann, R. B.; Moorberg, C.; Wong, A.; Waldrop, M. P.; Turetsky, M. R.

    2015-12-01

    Methane is a potent greenhouse gas, and wetlands represent the largest natural source of methane to the atmosphere. However, much of the methane generated in anoxic wetlands never gets emitted to the atmosphere; up to >90% of generated methane can get oxidized to carbon dioxide. Thus, oxidation is an important methane sink and changes in the rate of methane oxidation can affect wetland methane emissions. Most methane is aerobically oxidized at oxic-anoxic interfaces where rates of oxidation strongly depend on methane and oxygen concentrations. In wetlands, oxygen is often the limiting substrate. To improve understanding of belowground oxygen dynamics and its impact on methane oxidation, we deployed two planar optical oxygen sensors in a thermokarst bog in interior Alaska. Previous work at this site indicated that, similar to other sites, rates of methane oxidation decrease over the growing season. We used the sensors to track spatial and temporal patterns of oxygen concentrations over the growing season. We coupled these in-situ oxygen measurements with periodic oxygen injection experiments performed against the sensor to quantify belowground rates of oxygen consumption. We found that over the season, the thickness of the oxygenated water layer at the peatland surface decreased. Previous research has indicated that in sphagnum-dominated peatlands, like the one studied here, rates of methane oxidation are highest at or slightly below the water table. It is in these saturated but oxygenated locations that both methane and oxygen are available. Thus, a seasonal reduction in the thickness of the oxygenated water layer could restrict methane oxidation. The decrease in thickness of the oxygenated layer coincided with an increase in the rate of oxygen consumption during our oxygen injection experiments. The increase in oxygen consumption was not explained by temperature; we infer it was due to an increase in substrate availability for oxygen consuming reactions and

  19. Bringing back the rare - biogeochemical constraints of peat moss establishment in restored cut-over bogs

    NASA Astrophysics Data System (ADS)

    Raabe, Peter; Blodau, Christian; Hölzel, Norbert; Kleinebecker, Till; Knorr, Klaus-Holger

    2016-04-01

    In rewetted cut-over bogs in north-western Germany and elsewhere almost no spontaneous recolonization of hummock peat mosses, such as Sphagnum magellanicum, S. papillosum or S. rubellum can be observed. However, to reach goals of climate protection every restoration of formerly mined peatlands should aim to enable the re-establishment of these rare but functionally important plant species. Besides aspects of biodiversity, peatlands dominated by mosses can be expected to emit less methane compared to sites dominated by graminoids. To assess the hydrological and biogeochemical factors constraining the successful establishment of hummock Sphagnum mosses we conducted a field experiment by actively transferring hummock species into six existing restoration sites in the Vechtaer Moor, a large peatland complex with active peat harvesting and parallel restoration efforts. The mosses were transferred as intact sods in triplicate at the beginning of June 2016. Six weeks (mid-July) and 18 weeks later (beginning of October) pore water was sampled in two depths (5 and 20 cm) directly beneath the inoculated Sphagnum sods as well as in untreated control plots and analysed for phosphate, ferrous iron, ammonia, nitrate and total organic carbon (TOC). On the same occasions and additionally in December, the vitality of mosses was estimated. Furthermore, the increment of moss height between July and December was measured by using cranked wires and peat cores were taken for lab analyses of nutrients and major element inventories at the depths of pore water sampling. Preliminary results indicate that vitality of mosses during the period of summer water level draw down was strongly negatively related to plant available phosphate in deeper layers of the residual peat. Furthermore, increment of moss height was strongly negatively related to TOC in the upper pore waters sampled in October. Concentration of ferrous iron in deeper pore waters was in general significantly higher beneath

  20. Biogeochemical indicators of peatland degradation - a case study of a temperate bog in northern Germany

    NASA Astrophysics Data System (ADS)

    Kruger, J. P.; Leifeld, J.; Glatzel, S.; Szidat, S.; Alewell, C.

    2015-05-01

    Organic soils in peatlands store a great proportion of the global soil carbon pool and can lose carbon via the atmosphere due to degradation. In Germany, most of the greenhouse gas (GHG) emissions from organic soils are attributed to sites managed as grassland. Here, we investigated a land use gradient from near-natural wetland (NW) to an extensively managed (GE) to an intensively managed grassland site (GI), all formed in the same bog complex in northern Germany. Vertical depth profiles of δ13C, δ15N, ash content, C / N ratio and bulk density as well as radiocarbon ages were studied to identify peat degradation and to calculate carbon loss. At all sites, including the near-natural site, δ13C depth profiles indicate aerobic decomposition in the upper horizons. Depth profiles of δ15N differed significantly between sites with increasing δ15N values in the top soil layers paralleling an increase in land use intensity owing to differences in peat decomposition and fertilizer application. At both grassland sites, the ash content peaked within the first centimetres. In the near-natural site, ash contents were highest in 10-60 cm depth. The ash profiles, not only at the managed grassland sites, but also at the near-natural site indicate that all sites were influenced by anthropogenic activities either currently or in the past, most likely due to drainage. Based on the enrichment of ash content and changes in bulk density, we calculated the total carbon loss from the sites since the peatland was influenced by anthropogenic activities. Carbon loss at the sites increased in the following order: NW < GE < GI. Radiocarbon ages of peat in the topsoil of GE and GI were hundreds of years, indicating the loss of younger peat material. In contrast, peat in the first centimetres of the NW was only a few decades old, indicating recent peat growth. It is likely that the NW site accumulates carbon today but was perturbed by anthropogenic activities in the past. Together, all

  1. Evidence for Multiple Holocene Marine Impact Events: Ejecta in a Bog Core

    NASA Astrophysics Data System (ADS)

    Abbott, D. H.; Courty, M.; Breger, D.; Costa, S.; Gerard-Little, P.; Burckle, L.; Pekar, S.

    2006-12-01

    In a core from Tamarack Pond (a former bog) in the Hudson Highlands of New York, we found two layers containing marine microfossils. Because carbon rich sediments can be bioturbated over 20 cm depths, we give the layer thicknesses as 20 cm. The first layer is at 332-354 cm depth. It contains a radiolarian with a splashed on coating of Fe-Cr-Ni metal. It also contains a benthonic foraminiferal fossil. The second layer is at 432-454 cm depth. The second layer contains a degraded radiolarian fossil, a silicate with a splashed on coating of Fe-Cr-Ni metal, a carbon rich spherule containing Fe-Cr-Ni metal, and a grain of titanomagnetite with multiple craters. It also contains organic matter with Sn in it. As Tamarack Pond is quite far from the ocean, the marine fossils in the cores are unlikely to be windblown debris of Holocene age. A benthonic foraminifera is particularly unlikely to be blown by the wind. This conclusion is strengthened by the observation that the splashed on coating of Fe-Cr-Ni metal occurs in chondritic relative abundances with Fe>Cr>Ni. In grains with a thick layer of splashed metal, the Ni is sufficiently abundant to produce 3 distinct Ni peaks in the X-ray analysis. Such a high abundance of Ni coupled with chondritic relative abundances suggests that the Fe-Cr- Ni splash is derived from the vaporization of an extraterrestrial impactor. If we assume that the sedimentation rate of the Tamarack Pond core is the same as that of a previously dated core from nearby Sutherland Pond, the two layers have an uncorrected C-14 age of around 900-1200 B.C. for the layer at 332-354 cm and 2100 to 2400 B.C. for the layer at 432-454 cm. Both ages have a rough correspondence with times of climate downturn recorded in tree ring data (1159 and 2354 B.C.). These climate downturns cannot be explained by volcanic eruptions and are proposed to be cosmogenic in origin[1]. The older layer also corresponds in components to a previously studied circa 2350 B.C. impact ejecta

  2. Acetoclastic and hydrogenotrophic methane production and methanogenic populations in an acidic West-Siberian peat bog.

    PubMed

    Kotsyurbenko, Oleg R; Chin, Kuk-Jeong; Glagolev, Mikhail V; Stubner, Stephan; Simankova, Maria V; Nozhevnikova, Ala N; Conrad, Ralf

    2004-11-01

    Sites in the West Siberian peat bog 'Bakchar' were acidic (pH 4.2-4.8), low in nutrients, and emitted CH4 at rates of 0.2-1.5 mmol m(-2) h(-1). The vertical profile of delta13CH4 and delta13CO2 dissolved in the porewater indicated increasing isotope fractionation and thus increasing contribution of H2/CO2-dependent methanogenesis with depth. The anaerobic microbial community at 30-50 cm below the water table produced CH4 with optimum activity at 20-25 degrees C and pH 5.0-5.5 respectively. Inhibition of methanogenesis with 2-bromo-ethane sulphonate showed that acetate, phenyl acetate, phenyl propionate and caproate were important intermediates in the degradation pathway of organic matter to CH4. Further degradation of these intermediates indicated that 62-72% of the CH4 was ultimately derived from acetate, the remainder from H2/CO2. Turnover times of [2-14C]acetate were on the order of 2 days (15, 25 degrees C) and accounted for 60-65% of total CH4 production. Conversion of 14CO2 to 14CH4 accounted for 35-43% of total CH4 production. These results showed that acetoclastic and hydrogenotrophic methanogenesis operated closely at a ratio of approximately 2 : 1 irrespective of the incubation temperature (4, 15 and 25 degrees C). The composition of the archaeal community was determined in the peat samples by terminal restriction fragment length polymorphism (T-RFLP) analysis and sequencing of amplified SSU rRNA gene fragments, and showed that members of Methanomicrobiaceae, Methanosarcinaceae and Rice cluster II (RC-II) were present. Other, presumably non-methanogenic archaeal clusters (group III, RC-IV, RC-V, RC-VI) were also detected. Fluorescent in situ hybridization (FISH) showed that the number of Bacteria decreased (from 24 x 10(7) to 4 x 10(7) cells per gram peat) with depth (from 5 to 55 cm below the water table), whereas the numbers of Archaea slightly increased (from 1 x 10(7) to 2 x 10(7) cells per gram peat). Methanosarcina spp. accounted for about half of

  3. Methane production and oxidation patterns along a hydrological gradient in Luther Bog, Ontario

    NASA Astrophysics Data System (ADS)

    Praetzel, Leandra; Berger, Sina; Blodau, Christian

    2016-04-01

    Methane emissions from natural peatlands contribute significantly to the global budget of atmospheric CH4. In the northern hemisphere, where climate models predict rising temperatures and precipitation rates, these emissions are likely to rise. So far, little is known about the change of processes of methane production and oxidation, which influence the total amount of methane emissions, in peatland soils under warmer and wetter climate conditions. Our work focuses on anaerobic CH4 production and aerobic CH4 oxidation processes along a hydrological gradient in an ombotrophic bog in Ontario, Canada that was induced by creation of a reservoir in 1952. Along this transect, four sites were established differing in hydrologic conditions and vegetation patterns. We examined depth profiles of CO2 and CH4 concentrations and delta 13C isotope ratios in the peat using silicon samplers, dialysis chambers and multi-level piezometers. Chamber flux measurements were used to determine carbon fluxes. Isotope mass balances were calculated based on 13C isotope ratios and concentration profiles. By this approach the contribution of anaerobic CH4 and CO2 production to the total ER flux and the amount of oxidised CH4 can be determined. In addition meteorological data, soil temperatures, moisture and water table levels were recorded. By raising data at different sites and dates and with the help of the additionally recorded parameters, we will be able to make predictions about changing CH4 production and oxidation processes due to changing climate conditions. Preliminary results show that CH4 concentrations in the soil profile are higher at the sites which are exposed to stronger water table fluctuations, whereas CO2 concentration levels are lower at these sites. At all sites, CO2 concentrations in the peat are increasing but CH4 profiles are fairly stable. Moreover, isotopic signatures of 13CH4 indicate that the importance of the production pathway changes with depth from acetoclastic

  4. Reliance on prey-derived nitrogen by the carnivorous plant Drosera rotundifolia decreases with increasing nitrogen deposition.

    PubMed

    Millett, J; Svensson, B M; Newton, J; Rydin, H

    2012-07-01

    • Carnivory in plants is presumed to be an adaptation to a low-nutrient environment. Nitrogen (N) from carnivory is expected to become a less important component of the N budget as root N availability increases. • Here, we investigated the uptake of N via roots versus prey of the carnivorous plant Drosera rotundifolia growing in ombrotrophic bogs along a latitudinal N deposition gradient through Sweden, using a natural abundance stable isotope mass balance technique. • Drosera rotundifolia plants receiving the lowest level of N deposition obtained a greater proportion of N from prey (57%) than did plants on bogs with higher N deposition (22% at intermediate and 33% at the highest deposition). When adjusted for differences in plant mass, this pattern was also present when considering total prey N uptake (66, 26 and 26 μg prey N per plant at the low, intermediate and high N deposition sites, respectively). The pattern of mass-adjusted root N uptake was opposite to this (47, 75 and 86 μg N per plant). • Drosera rotundifolia plants in this study switched from reliance on prey N to reliance on root-derived N as a result of increasing N availability from atmospheric N deposition.

  5. Reliance on prey-derived nitrogen by the carnivorous plant Drosera rotundifolia decreases with increasing nitrogen deposition.

    PubMed

    Millett, J; Svensson, B M; Newton, J; Rydin, H

    2012-07-01

    • Carnivory in plants is presumed to be an adaptation to a low-nutrient environment. Nitrogen (N) from carnivory is expected to become a less important component of the N budget as root N availability increases. • Here, we investigated the uptake of N via roots versus prey of the carnivorous plant Drosera rotundifolia growing in ombrotrophic bogs along a latitudinal N deposition gradient through Sweden, using a natural abundance stable isotope mass balance technique. • Drosera rotundifolia plants receiving the lowest level of N deposition obtained a greater proportion of N from prey (57%) than did plants on bogs with higher N deposition (22% at intermediate and 33% at the highest deposition). When adjusted for differences in plant mass, this pattern was also present when considering total prey N uptake (66, 26 and 26 μg prey N per plant at the low, intermediate and high N deposition sites, respectively). The pattern of mass-adjusted root N uptake was opposite to this (47, 75 and 86 μg N per plant). • Drosera rotundifolia plants in this study switched from reliance on prey N to reliance on root-derived N as a result of increasing N availability from atmospheric N deposition. PMID:22506640

  6. Reconnaissance of uranium and copper deposits in parts of New Mexico, Colorado, Utah, Idaho, and Wyoming

    USGS Publications Warehouse

    Gott, Garland B.; Erickson, Ralph L.

    1952-01-01

    Because of the common association of uranium and copper in several of the commercial uranium deposits in the Colorado Plateau Province, a reconnaissance was made of several known deposits of copper disseminated through sandstone to determine whether they might be a source of uranium. In order to obtain more information regarding the relationship between copper, uranium and carbonaceous materials, some of the uraniferious asphaltrite deposits in the Shinarump conglomerate along the west flank of the San Rafael Swell were also investigated briefly. During this reconnaissance 18 deposits were examined in New Mexico, eight in Utah, two in Idaho, and one each in Wyoming and Colorado. No uranium deposits of commercial grade are associated with the copper deposits that were examined. The uraniferous asphaltites in the Shinarump conglomerate of Triassic age on the west flank of the San Rafael Swell, however, are promising from the standpoint of commercial uranium production. Spectrographic analyses of crude oil, asphalt, and bituminous shales show a rather consistent suite of trace metals including vanadium, nickel, copper, cobalt, chromium, lead zinc, and molybdenum. The similarity of the metal assemblage, including uranium of the San Rafael Swell asphaltites, to the metal assemblage in crude oil and other bituminous materials suggests that these metals were concentrated in the asphaltites from petroleum. However, the hypothesis that uranium minerals were already present before the hydrocarbons were introduced and that some sort of replacement or uranium minerals by carbon compounds was effected after the petroleum migrated into the uranium deposit should not be disregarded. The widespread association of uranium with asphaltic material suggests that it also may have been concentrated by some agency connected with the formation of petroleum. The problem of the association of uranium and other trace metals with hydrocarbons should be studied further both in the field and in

  7. Effect of trap color and height on captures of blunt-nosed and sharp-nosed leafhoppers (hemiptera: cicadellidae) and non-target arthropods in cranberry bogs

    Technology Transfer Automated Retrieval System (TEKTRAN)

    A series of field experiments were conducted in cranberry bogs in 2006-2010 to determine adult attraction of the two most economically important leafhopper pests of cultivated Vaccinium spp. in the northeast USA, the blunt-nosed leafhopper, Limotettix vaccinii, and sharp-nosed leafhopper, Scaphytopi...

  8. Rates and Controls of N2 Fixation in Sphagnum spp. along the Hydrological Gradient - Beaver Pond to Bog Transition at Mer Bleue, Ontario, Canada

    NASA Astrophysics Data System (ADS)

    Zivkovic, T.; Moore, T. R.

    2014-12-01

    Many northern bogs with low atmospheric N inputs acquire N only via N2-fixation. Little is known about rates and controls on N2-fixation in bogs. The aim of this study was to: 1) test the important ecological drivers for N2-fixation, 2) investigate seasonal and temporal patterns of N2 fixation, and 3) to estimate current N2-fixation rates at Mer Bleue bog. We used acetylene reduction assay (ARA) to measure N2-fixation from June-October 2013 and 2014 (currently ongoing field season) along a hydrological gradient (beaver pond, hollows and hummocks). The highest ARA rates in 2013 growing season occurred in the pond in floating Sphagnum cuspidatum mats (50.3 ± 12.9 μmol m-2 d-1 Mean ± Std Err) which were up to 2.5 times latger than the rates found in the hummock with the lowest water table depth throughout the season. Two rain events during the summer 2013 increased ARA rates in all plots by 1 to 4 times, suggesting that moisture availability may play a crucial role on N2 fixation potential in the field. We are currently investigating the role of moisture, temperature, PAR and nutrient content (N, phosphorous and metals) on ARA along the gradient. In addition, we are using 15N2 enrichment method to estimate N2 fixation rates and compare them to ARA method at Mer Bleue bog.

  9. Using a Thermokarst Bog Chronosequence to Examine Post-thaw Changes in Net Carbon Balance and the Interactions Between Permafrost, Vegetation, and Carbon

    NASA Astrophysics Data System (ADS)

    Manies, K.; Jones, M.; Waldrop, M. P.

    2015-12-01

    Northern forest soils and wetlands have served as carbon (C) sinks for thousands of years. The boreal region contains 50% of the world's soil organic C, with northern peatlands accounting for 30% of that pool. However, climate change in this region, in the form of warming air temperatures, has the potential to release a significant portion of this C due to changes in ecosystem structure and function. In particular, permafrost thaw in low-lying, moderately ice-rich areas results in the formation of collapse-scar bogs, dramatically altering the C cycle. Recent studies have shown that the transition from permafrost plateau to thermokarst bog results in the rapid loss of silvic (forest) peat, followed by a slow accumulation of C in post-thaw bog peat. Results from these studies suggest that this transition may turn these areas from net C sinks to C sources in the decades to centuries following thaw. Here we examine a bog chronosequence located within the Tanana River floodplain of Interior Alaska to determine if this pattern of C loss and gain holds true. Peat cores were taken to mineral soil from a permafrost plateau and three bogs with different ages of thaw (within the last several decades, within the last century, and within the past several centuries). All sites were located within the Bonanza Creek Long-term Ecological Research (LTER) site near Fairbanks, AK. We examined how the complex history of these thermokarst features can affect the C cycle. Macrofossil analysis reveals that most cores contained multiple cycles of permafrost aggradation and degradation, with the permafrost aggradation occurring epigenetically after peat initiated from a floodplain fen. Differences in vegetation communities that form peat, and the respective bulk densities associated with fens, permafrost plateaus, and collapse-scar bogs, resulted in different C accumulation rates. These data will provide insight into the fate of C within thermokarst bogs with complex permafrost histories in

  10. Microbial Community Structure and Activity Linked to Contrasting Biogeochemical Gradients in Bog and Fen Environments of the Glacial Lake Agassiz Peatland

    PubMed Central

    Lin, X.; Green, S.; Tfaily, M. M.; Prakash, O.; Konstantinidis, K. T.; Corbett, J. E.; Chanton, J. P.; Cooper, W. T.

    2012-01-01

    The abundances, compositions, and activities of microbial communities were investigated at bog and fen sites in the Glacial Lake Agassiz Peatland of northwestern Minnesota. These sites contrast in the reactivity of dissolved organic matter (DOM) and the presence or absence of groundwater inputs. Microbial community composition was characterized using pyrosequencing and clone library construction of phylogenetic marker genes. Microbial distribution patterns were linked to pH, concentrations of dissolved organic carbon and nitrogen, C/N ratios, optical properties of DOM, and activities of laccase and peroxidase enzymes. Both bacterial and archaeal richness and rRNA gene abundance were >2 times higher on average in the fen than in the bog, in agreement with a higher pH, labile DOM content, and enhanced enzyme activities in the fen. Fungi were equivalent to an average of 1.4% of total prokaryotes in gene abundance assayed by quantitative PCR. Results revealed statistically distinct spatial patterns between bacterial and fungal communities. Fungal distribution did not covary with pH and DOM optical properties and was vertically stratified, with a prevalence of Ascomycota and Basidiomycota near the surface and much higher representation of Zygomycota in the subsurface. In contrast, bacterial community composition largely varied between environments, with the bog dominated by Acidobacteria (61% of total sequences), while the Firmicutes (52%) dominated in the fen. Acetoclastic Methanosarcinales showed a much higher relative abundance in the bog, in contrast to the dominance of diverse hydrogenotrophic methanogens in the fen. This is the first quantitative and compositional analysis of three microbial domains in peatlands and demonstrates that the microbial abundance, diversity, and activity parallel with the pronounced differences in environmental variables between bog and fen sites. PMID:22843538

  11. Experimental warming delays autumn senescence in a boreal spruce bog: Initial results from the SPRUCE experiment

    NASA Astrophysics Data System (ADS)

    Richardson, Andrew; Furze, Morgan; Aubrecht, Donald; Milliman, Thomas; Nettles, Robert; Krassovski, Misha; Hanson, Paul

    2016-04-01

    Phenology is considered one of the most robust indicators of the biological impacts of global change. In temperate and boreal regions, long-term data show that rising temperatures are advancing spring onset (e.g. budburst and flowering) and delaying autumn senescence (e.g. leaf coloration and leaf fall) in a wide range of ecosystems. While warm and cold temperatures, day length and insolation, precipitation and water availability, and other factors, have all been shown to influence plant phenology, the future response of phenology to rising temperatures and elevated CO2 still remains highly uncertain because of the challenges associated with conducting realistic manipulative experiments to simulate future environmental conditions. At the SPRUCE (Spruce and Peatland Responses Under Climatic and Environmental Change) experiment in the north-central United States, experimental temperature (0 to +9° C above ambient) and CO2 (ambient and elevated) treatments are being applied to mature, and intact, Picea mariana-Sphagnum spp. bog communities in their native habitat through the use of ten large (approximately 12 m wide, 10 m high) open-topped enclosures. We are tracking vegetation green-up and senescence in these chambers, at both the individual and whole-community level, using repeat digital photography. Within each chamber, digital camera images are recorded every 30 minutes and uploaded to the PhenoCam (http://phenocam.sr.unh.edu) project web page, where they are displayed in near-real-time. Image processing is conducted nightly to extract quantitative measures of canopy color, which we characterize using Gcc, the green chromatic coordinate. Data from a camera mounted outside the chambers (since November 2014) indicate strong seasonal variation in Gcc for both evergreen shrubs and trees. Shrub Gcc rises steeply in May and June, and declines steeply in September and October. By comparison, tree Gcc rises gradually from March through June, and declines gradually from

  12. CH4 production via CO2 reduction in a temperate bog - A source of (C-13)-depleted CH4

    NASA Technical Reports Server (NTRS)

    Lansdown, J. M.; Quay, P. D.; King, S. L.

    1992-01-01

    The paper reports measurements, taken over two annual cycles, of the flux and delta(C-13) of CH4 released from an acidic peat bog located in the foothills of the Cascade Range in Washington state, U.S. Measurements of the rate of aceticlastic methanogenesis and CO2 reduction in peat soil, using (C-14)-labeled acetate and sodium bicarbonate, show that acetate was not an important CH4 precursor and that CO2 reduction could account for all of the CH4 production. The in situ kinetic isotope effect for CO2 reduction, calculated using the delta-(C-13) of soil water CO2 and CH4 flux, was 0.932 +/- 0.007.

  13. Interspecific differences in foliar 1 PAHs load between Scots pine, birch, and wild rosemary from three polish peat bogs.

    PubMed

    Mętrak, Monika; Aneta, Ekonomiuk; Wiłkomirski, Bogusław; Staszewski, Tomasz; Suska-Malawska, Małgorzata

    2016-08-01

    Pine needles are one of the most commonly used bioindicators of polycyclic aromatic hydrocarbons (PAHs) in the environment. Therefore, the main objective of the current research was the assessment of PAHs accumulation potential of Scots pine (Pinus sylvestris L.) needles in comparison to wild rosemary (Rhododendron tomentosum Harmaja) and birch (Betula spp.) leaves. Our study was carried out on three peat bogs subjected to different degree of anthropopression, which gave us also the opportunity to identify local emission sources. Pine needles had the lowest accumulation potential from all the studied species. The highest accumulation potential, and hence carcinogenic potential, was observed for wild rosemary leaves. As far as emission sources are concerned, the most pronounced influence on atmospheric PAHs loads had traditional charcoal production, resulting in great influx of heavy PAHs. Observed seasonal changes in PAHs concentrations followed the pattern of winter increase, caused mainly by heating season, and summer decrease, caused mainly by volatilization of light PAHs.

  14. [Decline of Activity and Shifts in the Methanotrophic Community Structure of an Ombrotrophic Peat Bog after Wildfire].

    PubMed

    Danilova, O V; Belova, S E; Kulichevskaya, I S; Dedysh, S N

    2015-01-01

    This study examined potential disturbances of methanotrophic communities playing a key role in reducing methane emissions from the peat bog Tasin Borskoye, Vladimir oblast, Russia as a result of the 2007 wildfire. The potential activity of the methane-oxidizing filter in the burned peatland site and the abundance of indigenous methanotrophic bacteria were significantly reduced in comparison to the undisturbed site. Molecular analysis of methanotrophic community structure by means of PCR amplification and cloning of the pmoAgene encoding particulate methane monooxygenase revealed the replacement of typical peat-inhabiting, acidophilic type II methanotrophic bacteria with type I methanotrophs, which are less active in acidic environments. In summary, both the structure and the activity of the methane-oxidizing filter in burned peatland sites underwent significant changes, which were clearly pronounced even after 7 years of the natural ecosystem recovery. These results point to the long-term character of the disturbances caused by wildfire in peatlands.

  15. CH4 production via CO2 reduction in a temperate bog - A source of (C-13)-depleted CH4

    NASA Astrophysics Data System (ADS)

    Lansdown, J. M.; Quay, P. D.; King, S. L.

    1992-09-01

    The paper reports measurements, taken over two annual cycles, of the flux and delta(C-13) of CH4 released from an acidic peat bog located in the foothills of the Cascade Range in Washington state, U.S. Measurements of the rate of aceticlastic methanogenesis and CO2 reduction in peat soil, using (C-14)-labeled acetate and sodium bicarbonate, show that acetate was not an important CH4 precursor and that CO2 reduction could account for all of the CH4 production. The in situ kinetic isotope effect for CO2 reduction, calculated using the delta-(C-13) of soil water CO2 and CH4 flux, was 0.932 +/- 0.007.

  16. [Decline of Activity and Shifts in the Methanotrophic Community Structure of an Ombrotrophic Peat Bog after Wildfire].

    PubMed

    Danilova, O V; Belova, S E; Kulichevskaya, I S; Dedysh, S N

    2015-01-01

    This study examined potential disturbances of methanotrophic communities playing a key role in reducing methane emissions from the peat bog Tasin Borskoye, Vladimir oblast, Russia as a result of the 2007 wildfire. The potential activity of the methane-oxidizing filter in the burned peatland site and the abundance of indigenous methanotrophic bacteria were significantly reduced in comparison to the undisturbed site. Molecular analysis of methanotrophic community structure by means of PCR amplification and cloning of the pmoAgene encoding particulate methane monooxygenase revealed the replacement of typical peat-inhabiting, acidophilic type II methanotrophic bacteria with type I methanotrophs, which are less active in acidic environments. In summary, both the structure and the activity of the methane-oxidizing filter in burned peatland sites underwent significant changes, which were clearly pronounced even after 7 years of the natural ecosystem recovery. These results point to the long-term character of the disturbances caused by wildfire in peatlands. PMID:27169243

  17. Interspecific differences in foliar 1 PAHs load between Scots pine, birch, and wild rosemary from three polish peat bogs.

    PubMed

    Mętrak, Monika; Aneta, Ekonomiuk; Wiłkomirski, Bogusław; Staszewski, Tomasz; Suska-Malawska, Małgorzata

    2016-08-01

    Pine needles are one of the most commonly used bioindicators of polycyclic aromatic hydrocarbons (PAHs) in the environment. Therefore, the main objective of the current research was the assessment of PAHs accumulation potential of Scots pine (Pinus sylvestris L.) needles in comparison to wild rosemary (Rhododendron tomentosum Harmaja) and birch (Betula spp.) leaves. Our study was carried out on three peat bogs subjected to different degree of anthropopression, which gave us also the opportunity to identify local emission sources. Pine needles had the lowest accumulation potential from all the studied species. The highest accumulation potential, and hence carcinogenic potential, was observed for wild rosemary leaves. As far as emission sources are concerned, the most pronounced influence on atmospheric PAHs loads had traditional charcoal production, resulting in great influx of heavy PAHs. Observed seasonal changes in PAHs concentrations followed the pattern of winter increase, caused mainly by heating season, and summer decrease, caused mainly by volatilization of light PAHs. PMID:27393196

  18. Are bogs reservoirs for emerging disease vectors? Evaluation of culicoides populations in the Hautes Fagnes Nature Reserve (Belgium).

    PubMed

    Zimmer, Jean-Yves; Smeets, François; Simonon, Grégory; Fagot, Jean; Haubruge, Eric; Francis, Frédéric; Losson, Bertrand

    2013-01-01

    Several species of Culicoides (Diptera: Ceratopogonidae) biting midges serve as biological vectors for the bluetongue virus (BTV) and the recently described Schmallenberg virus (SBV) in northern Europe. Since their recent emergence in this part of the continent, these diseases have caused considerable economic losses to the sheep and cattle industries. Much data is now available that describe the distribution, population dynamics, and feeding habits of these insects. However, little is known regarding the presence of Culicoides in unusual habitats such as peaty marshes, nor their potential vector capacity. This study evaluated Culicoides biting midges present in the bogs of a Belgian nature reserve compared to those residing at a nearby cattle farm. Culicoides were trapped in 2011 at four different sites (broadleaved and coniferous forested areas, open environments, and at a scientific station) located in the Hautes Fagnes Nature Reserve (Belgium). An additional light trap was operated on a nearby cattle farm. Very high numbers of biting midges were captured in the marshy area and most of them (70 to 95%) were Culicoides impunctatus, a potential vector of BTV and other pathogens. In addition, fewer numbers of C. obsoletus/C. scoticus species, C. chiopterus, and C. dewulfi were observed in the bogs compared to the farm. The wet environment and oligotrophic nature of the soil were probably responsible for these changes in the respective populations. A total of 297,808 Culicoides midges belonging to 27 species were identified during this study and 3 of these species (C. sphagnumensis, C. clintoni and C. comosioculatus) were described in Belgium for the first time.

  19. Diversity and community structure of Archaea inhabiting the rhizoplane of two contrasting plants from an acidic bog.

    PubMed

    Cadillo-Quiroz, Hinsby; Yavitt, Joseph B; Zinder, Stephen H; Thies, Janice E

    2010-05-01

    Plant root exudates increase nutrient availability and influence microbial communities including archaeal members. We examined the archaeal community inhabiting the rhizoplane of two contrasting vascular plants, Dulichium arundinaceum and Sarracenia purpurea, from an acidic bog in upstate NY. Multiple archaeal 16S rRNA gene libraries showed that methanogenic Archaea were dominant in the rhizoplane of both plants. In addition, the community structure (evenness) of the rhizoplane was found markedly different from the bulk peat. The archaeal community in peat from the same site has been found dominated by the E2 group, meanwhile the rhizoplane communities on both plants were co-dominated by Methanosarcinaceae (MS), rice cluster (RC)-I, and E2. Complementary T-RFLP analysis confirmed the difference between bulk peat and rhizoplane, and further characterized the dominance pattern of MS, RC-I, and E2. In the rhizoplane, MS was dominant on both plants although as a less variable fraction in S. purpurea. RC-I was significantly more abundant than E2 on S. purpurea, while the opposite was observed on D. arundinaceum, suggesting a plant-specific enrichment. Also, the statistical analyses of T-RFLP data showed that although both plants overlap in their community structure, factors such as plant type, patch location, and time could explain nearly a third of the variability in the dataset. Other factors such as water table, plant replicate, and root depth had a low contribution to the observed variance. The results of this study illustrate the general effects of roots and the specific effects of plant types on their nearby archaeal communities which in bog-inhabiting plants were mainly composed by methanogenic groups.

  20. Are Bogs Reservoirs for Emerging Disease Vectors? Evaluation of Culicoides Populations in the Hautes Fagnes Nature Reserve (Belgium)

    PubMed Central

    Zimmer, Jean-Yves; Smeets, François; Simonon, Grégory; Fagot, Jean; Haubruge, Eric; Francis, Frédéric; Losson, Bertrand

    2013-01-01

    Several species of Culicoides (Diptera: Ceratopogonidae) biting midges serve as biological vectors for the bluetongue virus (BTV) and the recently described Schmallenberg virus (SBV) in northern Europe. Since their recent emergence in this part of the continent, these diseases have caused considerable economic losses to the sheep and cattle industries. Much data is now available that describe the distribution, population dynamics, and feeding habits of these insects. However, little is known regarding the presence of Culicoides in unusual habitats such as peaty marshes, nor their potential vector capacity. This study evaluated Culicoides biting midges present in the bogs of a Belgian nature reserve compared to those residing at a nearby cattle farm. Culicoides were trapped in 2011 at four different sites (broadleaved and coniferous forested areas, open environments, and at a scientific station) located in the Hautes Fagnes Nature Reserve (Belgium). An additional light trap was operated on a nearby cattle farm. Very high numbers of biting midges were captured in the marshy area and most of them (70 to 95%) were Culicoides impunctatus, a potential vector of BTV and other pathogens. In addition, fewer numbers of C. obsoletus/C. scoticus species, C. chiopterus, and C. dewulfi were observed in the bogs compared to the farm. The wet environment and oligotrophic nature of the soil were probably responsible for these changes in the respective populations. A total of 297,808 Culicoides midges belonging to 27 species were identified during this study and 3 of these species (C. sphagnumensis, C. clintoni and C. comosioculatus) were described in Belgium for the first time. PMID:23799137

  1. Multi-scale hydroclimate reconstruction using co-located lake and bog records from Maine and comparison with other records from the Northeast US

    NASA Astrophysics Data System (ADS)

    Nolan, C.; Shuman, B. N.; Booth, R.; Jackson, S. T.

    2015-12-01

    Sedimentary lake-level records and ombrotrophic bog water-table depth records both document hydrologic variability over the Holocene. Lake level records have long temporal length (10,000+ years) and fidelity in preserving low-frequency trends and centennial to millennial length events. Hydrologic reconstructions based on peatland testate amoebae assemblage composition are sensitive to moisture variability at interannual to multidecadal time scales and precipitation on the bog surface is the sole moisture input. However, bog records are generally not as long as lake level records and bog development processes can confound centennial to millennial trends. In this study we present and combine new reconstructions from Giles Pond, Aurora, Maine, USA and Caribou Bog, Old Town, ME USA. The lake-level record from Giles Pond extends a network of lake-level records from southern New England that show an orbitally driven long-term trend toward wetter conditions punctuated by low-water phases in the mid- to late-Holocene that each lasted 100 to 400+ years. Some of these low lake level events appear to be synchronous across multiple sites in New England (Newby, et al. 2014 GRL). Preliminary data from Giles Pond suggest that some of these events extended all the way to Maine. Thus, there were New England-wide dry periods within the last 5000 years that lasted more than 100 years. These long low stands are unlike anything observed during the historical period and the interannual to decadal variability during these low stands is poorly understood. This leads to challenges in understanding the modern and future implications of the lake-level record alone. The Caribou Bog record also builds on a network of peatland water-table reconstructions from the Northeast, and contributes higher-resolution hydroclimate information that adds interannual to multidecadal texture to the centennial to millennial variability of the Giles Pond record. Our multiproxy approach allows us to use the

  2. How well do environmental archives of atmospheric mercury deposition in the Arctic reproduce rates and trends depicted by atmospheric models and measurements?

    PubMed

    Goodsite, M E; Outridge, P M; Christensen, J H; Dastoor, A; Muir, D; Travnikov, O; Wilson, S

    2013-05-01

    This review compares the reconstruction of atmospheric Hg deposition rates and historical trends over recent decades in the Arctic, inferred from Hg profiles in natural archives such as lake and marine sediments, peat bogs and glacial firn (permanent snowpack), against those predicted by three state-of-the-art atmospheric models based on global Hg emission inventories from 1990 onwards. Model veracity was first tested against atmospheric Hg measurements. Most of the natural archive and atmospheric data came from the Canadian-Greenland sectors of the Arctic, whereas spatial coverage was poor in other regions. In general, for the Canadian-Greenland Arctic, models provided good agreement with atmospheric gaseous elemental Hg (GEM) concentrations and trends measured instrumentally. However, there are few instrumented deposition data with which to test the model estimates of Hg deposition, and these data suggest models over-estimated deposition fluxes under Arctic conditions. Reconstructed GEM data from glacial firn on Greenland Summit showed the best agreement with the known decline in global Hg emissions after about 1980, and were corroborated by archived aerosol filter data from Resolute, Nunavut. The relatively stable or slowly declining firn and model GEM trends after 1990 were also corroborated by real-time instrument measurements at Alert, Nunavut, after 1995. However, Hg fluxes and trends in northern Canadian lake sediments and a southern Greenland peat bog did not exhibit good agreement with model predictions of atmospheric deposition since 1990, the Greenland firn GEM record, direct GEM measurements, or trends in global emissions since 1980. Various explanations are proposed to account for these discrepancies between atmosphere and archives, including problems with the accuracy of archive chronologies, climate-driven changes in Hg transfer rates from air to catchments, waters and subsequently into sediments, and post-depositional diagenesis in peat bogs

  3. Nitrogen deposition and prey nitrogen uptake control the nutrition of the carnivorous plant Drosera rotundifolia.

    PubMed

    Millett, J; Foot, G W; Svensson, B M

    2015-04-15

    Nitrogen (N) deposition has important negative impacts on natural and semi-natural ecosystems, impacting on biotic interactions across trophic levels. Low-nutrient systems are particularly sensitive to changes in N inputs and are therefore more vulnerable to N deposition. Carnivorous plants are often part of these ecosystems partly because of the additional nutrients obtained from prey. We studied the impact of N deposition on the nutrition of the carnivorous plant Drosera rotundifolia growing on 16 ombrotrophic bogs across Europe. We measured tissue N, phosphorus (P) and potassium (K) concentrations and prey and root N uptake using a natural abundance stable isotope approach. Our aim was to test the impact of N deposition on D. rotundifolia prey and root N uptake, and nutrient stoichiometry. D. rotundifolia root N uptake was strongly affected by N deposition, possibly resulting in reduced N limitation. The contribution of prey N to the N contained in D. rotundifolia ranged from 20 to 60%. N deposition reduced the maximum amount of N derived from prey, but this varied below this maximum. D. rotundifolia tissue N concentrations were a product of both root N availability and prey N uptake. Increased prey N uptake was correlated with increased tissue P concentrations indicating uptake of P from prey. N deposition therefore reduced the strength of a carnivorous plant-prey interaction, resulting in a reduction in nutrient transfer between trophic levels. We suggest that N deposition has a negative impact on D. rotundifolia and that responses to N deposition might be strongly site specific.

  4. Health assessment for Burnt Fly Bog National Priorities List Site, Marlboro, Monmouth County, New Jersey, Region 2. CERCLIS No. NJD980504997. Final report

    SciTech Connect

    Not Available

    1988-08-24

    The Burnt Fly Bog site, a National Priorities List site, is located near Marlboro, Monmouth County, New Jersey in the fringe area of the New Jersey Pine Barrens. The major contaminants at the site are polychlorinated biphenyls (PCBs) and lead. Both of these contaminants have been found in all environmental media at the site. Exposure to contaminants may occur from contact with soil, sediment, water, air, or biota from the site. In order to protect the public health, access to contaminated areas should not be permitted except for properly-protected remedial workers. Because of the potential for ground-water contamination, private well owners surrounding the site should be advised to connect to the public water system. In addition, the consumption of game animals, berries, fish, and other biota from Burnt Fly Bog should be discouraged unless it can be determined that they are free of contamination.

  5. The geochemistry of water near a surficial organic-rich uranium deposit, northeastern Washington State, U.S.A.

    USGS Publications Warehouse

    Zielinski, R.A.; Otton, J.K.; Wanty, R.B.; Pierson, C.T.

    1987-01-01

    The chemistry of three stream, three spring and six near-surface waters in the vicinity of a Holocene organic-rich uranium deposit is described, with particular emphasis on the chemistry of U. Results characterize the solution behavior of uranium as U-bearing water interacts with relatively undecomposed, surficial organic matter. Of the measured major and trace chemical species, only U is consistently highly enriched (17-318 ppb) relative to reported values for regional waters, or to literature values for waters in largely granitic terrains. R-mode factor analysis of the chemical data suggests that most U is present in a soluble form, but that some U is also associated with fine suspended particulates of clay, organic matter, or hydrous oxides. Calculations that apply thermodynamic data to predict U speciation in solution indicate the relative importance of uranyl carbonate and uranyl phosphate complexes. Analysis of more finely filtered samples (0.05 ??m vs. 0.45 ??m), and direct radiographic observations using fission-track detectors suspended in the waters indicate the presence of some uraniferous particulate matter. Application of existing thermodynamic data for uranous- and uranyl-bearing minerals indicates that all waters are undersaturated with U minerals as long as ambient Eh ??? +0.1 v. If coexisting surface and near-surface waters are sufficiently oxidizing, initial fixation of U in the deposit should be by a mechanism of adsorption. Alternatively, more reducing conditions may prevail in deeper pore waters of the organic-rich host sediments, perhaps leading to direct precipitation or diagenetic formation of U4+ minerals. A 234U 238U alpha activity ratio of 1.08 ?? 0.02 in a spring issuing from a hillslope above the deposit suggests a relatively soluble source of U. In contrast, higher activity ratios of 234U 238U (??? 1.3) in waters in contact with the uraniferous valley-fill sediments suggest differences in the nature of interaction between groundwater

  6. Greenhouse gas emissions from rewetted bog peat extraction sites and a Sphagnum cultivation site in Northwest Germany

    NASA Astrophysics Data System (ADS)

    Beyer, C.; Höper, H.

    2014-03-01

    During the last three decades, an increasing area of drained peatlands was rewetted. This was done with the objective to convert these sites from sources back to sinks or, at least, to much smaller sources of greenhouse gases (GHG). However, available data is still scarce, especially on the long-term climatic effects of rewetting of temperate bogs. Moreover, first field trials are established for Sphagnum cultivating (paludiculture) on wet bog sites and an assessment of the climate impact of such measures has not been studied yet. We conducted a field study on the exchange of carbon dioxide, methane and nitrous oxide at three rewetted sites with a gradient from dry to wet conditions and at a Sphagnum cultivation site in NW Germany over more than two years. Gas fluxes were measured using transparent and opaque closed chambers. The ecosystem respiration (CO2) and the net ecosystem exchange (CO2) were modelled in high time resolution using automatically monitored climate data. Measured and modelled values fit very well together (R2 between 0.88 and 0.98). Annually cumulated gas flux rates, net ecosystem carbon balances (NECB) and global warming potential (GWP) balances were determined. The annual net ecosystem exchange (CO2) varied strongly at the rewetted sites (from -201.7 ± 126.8 to 29.7 ± 112.7 g CO2-C m-2 a-1) due to different weather conditions, water level and vegetation. The Sphagnum cultivation site was a sink of CO2 (-118.8 ± 48.1 and -78.6 ± 39.8 g CO2-C m-2 a-1). The yearly CH4 balances ranged between 16.2 ± 2.2 and 24.2 ± 5.0 g CH4-C m-2 a-1 at two inundated sites, while one rewetted site with a comparatively low water level and the Sphagnum farming site show CH4 fluxes close to zero. The net N2O fluxes were low and not significantly different between the four sites. The annual NECB at the rewetted sites was between -183.8 ± 126.9 and 51.6 ± 112.8 g CO2-C m-2 a-1 and at the Sphagnum cultivating site -114.1 ± 48.1 and -75.3 ± 39.8 g CO2-C m-2 a-1

  7. Greenhouse gas exchange of rewetted bog peat extraction sites and a Sphagnum cultivation site in northwest Germany

    NASA Astrophysics Data System (ADS)

    Beyer, C.; Höper, H.

    2015-04-01

    During the last decades an increasing area of drained peatlands has been rewetted. Especially in Germany, rewetting is the principal treatment on cutover sites when peat extraction is finished. The objectives are bog restoration and the reduction of greenhouse gas (GHG) emissions. The first sites were rewetted in the 1980s. Thus, there is a good opportunity to study long-term effects of rewetting on greenhouse gas exchange, which has not been done so far on temperate cutover peatlands. Moreover, Sphagnum cultivating may become a new way to use cutover peatlands and agriculturally used peatlands as it permits the economical use of bogs under wet conditions. The climate impact of such measures has not been studied yet. We conducted a field study on the exchange of carbon dioxide, methane and nitrous oxide at three rewetted sites with a gradient from dry to wet conditions and at a Sphagnum cultivation site in NW Germany over the course of more than 2 years. Gas fluxes were measured using transparent and opaque closed chambers. The ecosystem respiration (CO2) and the net ecosystem exchange (CO2) were modelled at a high temporal resolution. Measured and modelled values fit very well together. Annually cumulated gas flux rates, net ecosystem carbon balances (NECB) and global warming potential (GWP) balances were determined. The annual net ecosystem exchange (CO2) varied strongly at the rewetted sites (from -201.7 ± 126.8 to 29.7± 112.7g CO2-C m-2 a-1) due to differing weather conditions, water levels and vegetation. The Sphagnum cultivation site was a sink of CO2 (-118.8 ± 48.1 and -78.6 ± 39.8 g CO2-C m-2 a-1). The annual CH4 balances ranged between 16.2 ± 2.2 and 24.2 ± 5.0g CH4-C m-2 a-1 at two inundated sites, while one rewetted site with a comparatively low water level and the Sphagnum farming site show CH4 fluxes close to 0. The net N2O fluxes were low and not significantly different between the four sites. The annual NECB was between -185.5 ± 126.9 and 49

  8. A Record of Moisture History in Hawaii since the Arrival of Humans Inferred from Testate Amoebae and Cladocera Fossils Preserved in Bog Sediments

    NASA Astrophysics Data System (ADS)

    Barrett, K.; Kim, S. H.; Hotchkiss, S.

    2015-12-01

    Around AD 800, Polynesians arrived on the Hawaiian Islands where they expanded and intensified distinct agricultural practices in the islands' wet and dry regions. Dryland farming productivity in particular would have been sensitive to atmospheric rearrangements of the ENSO and PDO systems that affect rainfall in Hawaii. The few detailed terrestrial paleoclimate records in Hawaii are mainly derived from vegetation proxies (e.g. pollen, seeds, fruits, and plant biomarkers) which are heavily influenced by widespread landscape modification following human arrival. Here we present initial results of an independent paleomoisture proxy: fossil remains of moisture-sensitive testate amoebae (Protozoa: Rhizopoda) and cladocera (water fleas) preserved in continuous bog sediments on Kohala Volcano uplsope of the ancient Kohala agricultural field system, one of the largest dryland field systems in Hawaii. Hydrologic conditions inferred from testate amoebae and cladoceran fossil assemblages correlate with observed decadal moisture regimes in Hawaii and state changes of the PDO system during the last century. Testate ameoabe and cladoceran fossils in older sediments reveal an alternating history of very wet, lake-forming conditions on the bog surface to periods when bog soils were much drier than today's, demonstrating that this method can be paired with vegetation proxies to provide a better understanding of hydroclimate variability in prehistoric Hawaii.

  9. 13C/Palynological evidence of differential residence times of organic carbon prior to its sedimentation in East African Rift Lakes and peat bogs

    NASA Astrophysics Data System (ADS)

    Hillaire-Marcel, Claude; Aucour, Anne-Marie; Bonnefille, Raymonde; Riollet, Guy; Vincens, Annie; Williamson, David

    Most terrestrial plants producing large amounts of organic matter in the East African Rift follow the Calvin (C3) photosynthetic pathway. Their end products have δ13C values of ca. -27 ± 2‰ (vs. PDB). On the contrary, most Cyperaceae (notably Cyperus papyrus and C. latifolius) are characterized by higher 13C contents ° 13C = -10.5 ± 1‰ ) in relation to their Hatch and Slack (C4) photosynthetic cycle. In consequence, δ13C values in total organic matter (TOM) from peat bog or lake cores essentially responded to the proportion of detritus from C4-Cyperaceae. Immediate evidence of the development or disappearance of Cyperaceae around lake margins or in peat bogs can be found in pollen assemblages. Lag times between pollen signals and correlative ° 13C shifts in TOM from cores are therefore indicative of the residence time of organic matter prior to its sedimentation. Delayed sedimentation of TOM will result in 14C anomalies which depend on several parameters, most of them being site specific as shown by examples from a peat bog in Burundi and from southern Lake Tanganyika. An independent assessment of the chronology by high resolution paleomagnetic correlations indicates a ca. 1.5 ka apparent 14C age of TOM in Lake Tanganyika at the Pleistocene-Holocene transition.

  10. Peat bogs offer a reliable, local source of fuel in several states

    SciTech Connect

    Punwani, D.V.

    1981-10-01

    With total estimated US peat resources equivalent to the energy content of 240-billion bbl of oil, peat could be a significant energy resource even if only a fraction of it can be recovered. Resource estimates include only those areas (mostly in eight states) with at least 80 acres/sq mi of peat, where the deposits are at least 4 ft deep. Peat fuel properties, new equipment for peat harvesting and dewatering, and modern combustion technology are described. Conversion to synthetic fuels looks promising.

  11. Age-dependent impacts of peatland restoration on the net ecosystem CO2 exchange of blanket bogs in Northern Scotland

    NASA Astrophysics Data System (ADS)

    Hambley, Graham; Hill, Timothy; Saunders, Matthew; Arn Teh, Yit

    2015-04-01

    The Flow Country of Northern Scotland is the largest area of contiguous blanket bog in the UK covering an area in excess of 400 km2. This region is the single largest peat and soil C repository in the UK, and plays a key role in mediating regional atmospheric exchanges of greenhouse gases (GHGs) such as carbon dioxide (CO2), methane (CH4) and water vapour (H2O). However, these peatlands were subject to significant afforestation in the 1980s, where large areas of blanket bog were drained and planted with Sitka spruce (Picea sitchensis) and Lodgepole Pine (Pinus contorta), resulting in modifications to micro-topographic features, vegetation composition and soil properties such as bulk density and water holding capacity, all of which are known to influence the production and emission of key GHGs. Since the late 1990s restoration work has been undertaken to remove forest plantations and to restore the peatland areas by raising the water table, predominantly by drain and furrow blocking, in order to encourage the recolonisation of Sphagnum species. Here we report findings from an eddy covariance study of CO2 and H2O exchange from an unmanaged peatland and a chronosequence of restored peatland sites, which were felled in 1998 and 2004. Located within the Forsinard Flows National Nature Reserve in Northern Scotland, these sites are being studied to better understand the key drivers of carbon dynamics in these ecosystems and also assess the age-dependent impacts of peatland restoration on the net CO2 sink strength. Preliminary data show rates of CO2 uptake increased with time since restoration, with peak assimilation rates of -9.9 and -14.4 micro mol CO2 m-2 s-1 measured at the 10 and 16 year old restoration sites, respectively. Carbon losses through ecosystem respiration followed a similar pattern. The data collected to date indicates that while peatland restoration is actively increasing CO2 uptake at each of the sites, more long-term observational data is required to

  12. Carbon dioxide fluxes over a raised open bog at the Kinosheo Lake tower site during the Northern Wetlands Study (NOWES)

    NASA Technical Reports Server (NTRS)

    Neumann, H. H.; Den Hartog, G.; King, K. M.; Chipanshi, A. C.

    1994-01-01

    Measurements of carbon dioxide concentration and flux were made above a raised open bog at Lake Kinosheo in the southern Hudson Bay lowlands during the Northern Wetlands Study (NOWES) experiment in 1990. The flux measurements were made using micrometeorological techniques. They provide the first nondisturbing, larger-scale CO2 flux measurements for this ecosystem and are the first to integrate the exchange over the whole 24 hours of the day. Continuous concentration measurements by infrared gas analyzers (IRGA) and spot flask samples were taken over the period July 1 to July 29. Afternoon CO2 values were only 5 to 7 parts per million by volume (ppmv) lower than measurements over the same period at Canadian background monitoring stations. This suggested that there was little draw-down by local photosynthetic sinks. CO2 fluxes were measured at 8 and 18 m by Bowen ratio and eddy correlation methods, respectively. The methods produced comparable results on averaged data but often diverged considerably on individual half-hour results. Fluxes were small. Daytime values averaged to -0.068 mg/sq m/s by eddy correlation and -0.077 mg/sq m/s by Bowen ratio over the period June 25 to July 28 (negative denotes downward flux), while at night, flux densities were +0.062 mg/sq m/s and +0.085 mg/sq m/s. Integration of the mean diurnal curve gave a net flux of -1.7 g/sq m/d. Comparable data for this type of ecosystem were not found. However, Coyne and Kelley (1975), measuring near Barrow, Alaska, over wet meadow tundra dominated by sedges and grasses, found net fluxes of -7.2 g/sq m/d. Typical net CO2 fluxes from other active temperature ecosystems have been found to be -10 to -20 g/sq m/d (Monteith, 1976). Mean half hourly fluxes were almost constant at +0.06 mg/sq m/s through the nighttime hours. About one half-hour after sunrise the flux reversed direction. Uptake peaked about 0900 eastern daylight time (EDT) and then gradually declined but remained downward until near sunset

  13. Geochemical response of a calcareous fen to road salt contamination during snow melt and precipitation events: Kampoosa Bog, Stockbridge, MA

    NASA Astrophysics Data System (ADS)

    Rhodes, A. L.; Guswa, A. J.

    2008-12-01

    Kampoosa Bog is the largest and most diverse calcareous lake-basin fen remaining in Massachusetts, and it is one of the state's elite Areas of Critical Environmental Concern (ACEC). The ground water chemistry of the fen has been greatly altered by road salt runoff (NaCl) from the Massachusetts Turnpike, which crosses the northern margin of the wetland complex. Ground water samples collected at different depths within the wetland, measurements of exchangeable Na from an eight-meter core, and hydraulic conductivity measurements suggest that ground water flow and contamination is largely a near- surface phenomenon. Detailed sampling of surface and ground waters during three spring snow melt events and one precipitation event characterizes the geochemical response of the wetland to hydrologic events. Overall, Na:Cl ratios for surface and ground water samples are less than one, and sodium and chloride imbalances suggest that 20-30% of sodium from rock salt is stored on cation exchange sites on organic material. Na:Cl ratios greater than one for fen ground water sampled during Snow Melt 2007 suggest that sodium can be released from cation exchange sites back to ground water under dilute conditions. The total mass of Na and Cl exported from the wetland is greatest under conditions of high discharge. The flux of dissolved salts at the outlet of the fen during Snow Melt 2005 accounts for ~ 24% Na and ~ 32% Cl of rock salt added to the Massachusetts Turnpike during 2004-2005. Estimates of annual fluxes of Na and Cl are on par with the amount of road salt applied, and sodium and chloride concentrations in shallow groundwater have decreased since 2002. The months of March, April and May are the primary months for salt export, accounting for more than half of the annual salt flux in 2005. Concerning the annual net export of sodium and chloride, large rain events may be more important with removing dissolved salts from the fen than snow melt because snow melt also is a time when

  14. The Brenner Moor - A saline bog as a source for halogenated and non-halogenated volatile compounds

    NASA Astrophysics Data System (ADS)

    Krause, T.; Studenroth, S.; Furchner, M.; Hoffman, A.; Lippe, S.; Kotte, K.; Schöler, H. F.

    2012-04-01

    The Brenner Moor is a small bog in the catchment area of the river Trave located in Schleswig-Holstein, North Germany, between Baltic and North Sea. The bog is fed by several saline springs with chloride concentrations up to 15 g/L. The high chloride concentrations and the high organic content of the peat make the Brenner Moor an ideal source for the abiotic formation of volatile organic halogenated compounds (VOX). VOX play an important role in the photochemical processes of the lower atmosphere and information on the atmospheric input from saline soils like the Brenner Moor will help to understand the global fluxes of VOX. Soil samples were taken in spring 2011 from several locations and depths in the vicinity of the Brenner Moor. The samples were freeze-dried, ground and incubated in water emphasising an abiotic character for the formation of volatile organic compounds. 1,2-dichloroethane and trichloromethane are the main halogenated compounds emitted from soils of the Brenner Moor. The abiotic formation of trichloromethane as well as other trihalomethanes has been part of intensive studies. A well known source is the decarboxylation of trichloroacetic acid and trichloroacetyl-containing compounds to trichloromethane [1]. Huber et al. discovered another pathway in which catechol, as a model compound for organic substances, is oxidised under Fenton-like conditions with iron(III), hydrogen peroxide and halides to form trihalomethanes [2]. Besides the halogenated compounds, the formation of sulphur compounds such as dimethyl sulfide and dimethyl disulfide and several furan derivatives could be detected which also have an impact on atmospheric chemistry, especially particle formation of clouds. Furan, methylfuran and dimethylfuran are compounds that can be obtained under Fenton-like oxidation from catechol, methyl- and dimethylcatechol and are known to be produced in natural soils [3]. A novel class of furan derivatives that are formed under abiotic conditions from

  15. Relationships among the water table depth, water and surface elevations, and the composition of vegetation in a temperate hummocky, ombrogenic, oligotrophic raised shrub bog

    NASA Astrophysics Data System (ADS)

    Roulet, Nigel; Wilson, Paul; Malhora, Avni

    2016-04-01

    Microtopography, such as hummocks and hollows, pools, ridges and lawns are features that are believed to be a consequence of feedbacks among the local hydrology and the production and decomposition of organic material. To deductively test some of the postulates derived from several theoretical studies of the development of patterning on peatlands, over two consecutive years we examined the spatial and temporal relationships among the hummock - hollow microtopography, water table depths (WTD) and water elevations (WTE) in a raised, ombrotrophic bog (Mer Bleue, Canada) that has extensive and well developed microtopography. In each of two 20 x 20 m plots we measured the surface elevation at more than 1,000 points, the WTDs manually every two to three weeks at 100 wells located on a 2 x 2 m grid, and WTDs continuously at more than 20 sites at adjacent hummocks and hollows. In addition to the physical measurements we also measured the spatial pattern of the vegetation communities. The average difference in elevation between the hummocks and hollows was ~ 0.5 m and as was expected the WTDs were shallower in the hollows than under the hummocks. The spatial variability in WTDs over time was very consistent. We tested the coherence between WTDs and surface elevation and found for a total of 46 spatial surveys over the two years and both plots the slopes from mixed modelled regressions were not significantly different for over 80% of the surveys. The difference in WTEs in adjacent microtopographic features (i.e. water levels referenced to a common datum), which determine the hydraulic gradients between hummocks and hollows, was quite small. The small gradients and the consistent coherence between WTDs and surface elevation suggests there is little lateral movement of water among the microtopographic features. The vegetation analysis showed the plot closer to the center, the apex, of the bog had stronger relationships among WTD-microtopography and vegetation than a plot

  16. Holocene palaeohydrological history of the Tǎul Muced peat bog (Northern Carpathians, Romania) based on testate amoebae (Protozoa) and plant macrofossils

    NASA Astrophysics Data System (ADS)

    Cosmin Diaconu, Andrei; Feurdean, Angelica; Lamentowicz, Mariusz; Gałka, Mariusz; Tanţǎu, Ioan

    2016-04-01

    Knowledge of past local vs. regional hydro-climate variability is a priority in climate research. This is because ecosystems and human depend on local climatic conditions and the magnitude of these climate changes is more variable at local and regional rather than at global scales. Ombrotrophic bogs are highly suitable for hydro-climate reconstructions as they are entirely dependent on the water from precipitation. We used stratigraphy, radiocarbon dating, testate amoebae (TA) and plant macrofossils on a peat profile from an ombrotrophic bog (Tǎul Muced) located in the Biosphere Reserve of the Rodna National Park Romania. We performed quantitative reconstruction of the depth to water table (DWT) and pH over the last 8000 years in a continental area of CE Europe. We identified six main stages in the development of the bog based on changes in TA assemblages in time. Wet conditions and pH between 2 and 4.5 were recorded between 4600-2750 and 1300-400 cal. yr BP, by the occurrence of Archerella flavum, Amphitrema wrightianum and Hyalosphenia papilio. This was associated to a local vegetation primarily composed of Sphagnum magellanicum and S. angustifolium. Dry stages and pH of 2.5 to 5 were inferred between 7550-4600, 2750-1300 and -50 cal. yr BP, by the dominance of Nebela militaris, Difflugia pulex and Phryganella acropodia. These overall dry conditions were also connected with increased abundance of Eriophorum vaginatum. The period between 400 and -50 cal. yr BP was characterized by a rapid shift from dry to wet conditions on the surface of the bog. Vegetation shifted from Sphagnum magellanicum to Sphagnum russowii dominated community. Our reconstruction remains in relatively good agreement with other palaeohydrological records from Central Eastern Europe. However, it shows contrasting conditions to others particularly with records from NW Europe. The valuable information regarding bog hydrology offered by our record puts an accent on the need of more regional TA

  17. Application of paleoDNA for identification of paleotsunami deposits

    NASA Astrophysics Data System (ADS)

    Szczucinski, W.; Pawlowska, J.; Lejzerowicz, F.; Nishimura, Y.; Kokocinski, M.; Majewski, W.; Nakamura, Y.; Pawlowski, J.

    2015-12-01

    The identification of sedimentary records of paleotsunamis is the key to tsunami hazard assessment. However, it is often challenging to distinguish the tsunami deposits due to their variability, influence of local context, variable sediment sources, as well as postdepositional alterations. Among the most commonly used approaches to identify paleotsunami is the study of microfossils (e.g. foraminifera, diatoms). They are most commonly used to show marine origin of sediments. The common problem with microfossils in coastal settings (eg. marshes, peat bogs) is that they may not be preserved. For instance, it was found during studies on post-depositional changes of 2004 tsunami deposits and in paleotsunami deposits in Thailand that the tests composed of calcium carbonate as well as from silica have been largely dissolved with time. The rapid progress in paleogenetic studies suggests that analyses of DNA preserved in marine sediments may be a new research direction. A recent successful application of the method to the deep sea and fjord sediments, greater than 30,000 years old proved that it is possible to extract DNA and identify it from sediments that are affected by oxygenated waters and bioturbating organisms. Here we apply the paleogenetic studies for a series of paleotsunami deposits from Urahoro, eastern Hokkaido Island, Japan dated to be from several hundreds of years to more than 2000 years old based on tephrochronology. The sandy tsunami deposits intercalated by muddy peat contained rare diatoms of various origin but foraminifera and radiolaria tests were missing. Nevertheless, we were able to retrieve short fragments of the foraminiferal DNA from marine species using high-throughput sequencing technology. Our study provides first evidence that eukaryotic DNA can be preserved in tsunami deposits in coastal marsh environment for as long as 2000 years even in absence of any micropaleontological evidence. Thus paleoDNA analyses may provide a new useful tool to

  18. A carbon accumulation maximum during the Medieval Climate Anomaly in the world’s biggest bog, Siberia

    NASA Astrophysics Data System (ADS)

    Beilman, D.; MacDonald, G. M.

    2009-12-01

    The West Siberia Lowland is the most carbon-rich northern wetland region, holding an important portion of total northern peatland carbon (70 Gt of 270-450 Gt C) mainly in the southern lowland (44 Gt) in very large peatlands. The largest of these, the Great Vasyugan Bog complex, spans 63,252 km2 and alone holds ~11 Gt C. Our previous work has shown that recent-past growth of WSL peat C pool has been greatest in southern WSL in large peatlands close to the southern limit of peatland distribution. In this study, we investigate a Great Vasyugan site to investigate peat carbon sensitivity in two ways: 1) assess past changes in vegetation, species-specific 13C geochemistry, and rate of carbon accumulation relative to recent-past climate variation, and 2) assess the relative lability of this deep peat C through laboratory incubations. Carbon accumulation over the last 2000 years, a period of relatively consistent vegetation and litter inputs but variable local hydrology, reached a maximum between 1150 and 1350 AD during Medieval Climate Anomaly conditions. A carbon accumulation minimum occurred between about 1350 and 1550 AD. Regardless of depth, age, or rate of carbon burial, deep peat from between 30 and 230 cm below the surface showed a similar rate of potential aerobic respiration that changed little over 42 days of incubation. Taken together, these data suggest that in some peatlanlds warmer and hydrologically-variable conditions can promote long-term belowground carbon storage.

  19. The structure of the microbial communities in low-moor and high-moor peat bogs of Tomsk oblast

    NASA Astrophysics Data System (ADS)

    Dobrovol'skaya, T. G.; Golovchenko, A. V.; Kukharenko, O. S.; Yakushev, A. V.; Semenova, T. A.; Inisheva, L. A.

    2012-03-01

    The number, structure, and physical state of the microbial communities in high-moor and low-moor peat bogs were compared. Distinct differences in these characteristics were revealed. The microbial biomass in the high-moor peat exceeded that in the low-moor peat by 2-9 times. Fungi predominated in the high-moor peat, whereas bacteria were the dominant microorganisms in the low-moor peat. The micromycetal complexes of the high-moor peat were characterized by a high portion of dark-colored representatives; the complexes of the low-moor peat were dominated by fast-growing fungi. The species of the Penicillum genus were dominant in the high-moor peat; the species of Trichoderma were abundant in the low-moor peat. In the former, the bacteria were distinguished as minor components; in the latter, they predominated in the saprotrophic bacterial complex. In the high-moor peat, the microorganisms were represented by bacilli, while, in the low-moor peat, by cytophages, myxobacteria, and actinobacteria. The different physiological states of the bacteria in the studied objects reflecting the duration of the lag phase and the readiness of the metabolic system to consume different substrates were demonstrated for the first time. The relationships between the trophic characteristics of bacterial habitats and the capacity of the bacteria to consume substrates were established.

  20. History and environmental impact of mining activity in Celtic Aeduan territory recorded in a peat bog (Morvan, France).

    PubMed

    Monna, F; Petit, C; Guillaumet, J P; Jouffroy-Bapicot, I; Blanchot, C; Dominik, J; Losno, R; Richard, H; Lévêque, J; Chateau, C

    2004-02-01

    The present study aims to document historical mining and smelting activities by means of geochemical and pollen analyses performed in a peat bog core collected around the Bibracte oppidum (Morvan, France), the largest settlement of the great Aeduan Celtic tribe (ca. 180 B.C. to 25 A.D.). The anthropogenic Pb profile indicates local mining operations starting from the Late Bronze Age, ca. cal. 1300 B.C. Lead inputs peaked at the height of Aeduan civilization and then decreased after the Roman conquest of Gaul, when the site was abandoned. Other phases of mining are recognized from the 11th century to modern times. They have all led to modifications in plant cover, probably related in part to forest clearances necessary to supply energy for mining and smelting. Zn, Sb, Cd, and Cu distributions may result from diffusional and biological processes or from the influence of groundwater and underlying mineral soil, precluding their interpretation for historical reconstruction. The abundance of mineral resources, in addition to the strategic location, might explain why early settlers founded the city of Bibracte at that particular place. About 20% of the anthropogenic lead record was accumulated before our era and about 50% before the 18th century, which constitutes a troublesome heritage. Any attempts to develop control strategies in accumulating environments should take into account past human activities in order to not overestimate the impact of contemporary pollution.

  1. Mining for Nonribosomal Peptide Synthetase and Polyketide Synthase Genes Revealed a High Level of Diversity in the Sphagnum Bog Metagenome

    PubMed Central

    Müller, Christina A.; Oberauner-Wappis, Lisa; Peyman, Armin; Amos, Gregory C. A.; Wellington, Elizabeth M. H.

    2015-01-01

    Sphagnum bog ecosystems are among the oldest vegetation forms harboring a specific microbial community and are known to produce an exceptionally wide variety of bioactive substances. Although the Sphagnum metagenome shows a rich secondary metabolism, the genes have not yet been explored. To analyze nonribosomal peptide synthetases (NRPSs) and polyketide synthases (PKSs), the diversity of NRPS and PKS genes in Sphagnum-associated metagenomes was investigated by in silico data mining and sequence-based screening (PCR amplification of 9,500 fosmid clones). The in silico Illumina-based metagenomic approach resulted in the identification of 279 NRPSs and 346 PKSs, as well as 40 PKS-NRPS hybrid gene sequences. The occurrence of NRPS sequences was strongly dominated by the members of the Protebacteria phylum, especially by species of the Burkholderia genus, while PKS sequences were mainly affiliated with Actinobacteria. Thirteen novel NRPS-related sequences were identified by PCR amplification screening, displaying amino acid identities of 48% to 91% to annotated sequences of members of the phyla Proteobacteria, Actinobacteria, and Cyanobacteria. Some of the identified metagenomic clones showed the closest similarity to peptide synthases from Burkholderia or Lysobacter, which are emerging bacterial sources of as-yet-undescribed bioactive metabolites. This report highlights the role of the extreme natural ecosystems as a promising source for detection of secondary compounds and enzymes, serving as a source for biotechnological applications. PMID:26002894

  2. Chromobacterium vaccinii sp. nov., isolated from native and cultivated cranberry (Vaccinium macrocarpon Ait.) bogs and irrigation ponds.

    PubMed

    Soby, Scott D; Gadagkar, Sudhindra R; Contreras, Cristina; Caruso, Frank L

    2013-05-01

    A large number of Gram-negative, motile, mesophilic, violacein-producing bacteria were isolated from the soils and roots of Vaccinium macrocarpon Ait. and Kalmia angustifolia L. plants and from irrigation ponds associated with wild and cultivated cranberry bogs in Massachusetts, USA. Phylogenetic analyses of 16S rRNA gene sequences placed these isolates in a clade with Chromobacterium species, but the specialized environment from which they were isolated, their low genomic DNA relatedness with Chromobacterium violaceum ATCC 12472(T) and C. subtsugae PRAA4-1(T), significant differences in fatty acid composition and colony morphology indicate that the cranberry and Kalmia isolates comprise a separate species of Chromobacterium, for which the name Chromobacterium vaccinii sp. nov. is proposed. Strain MWU205(T) ( = ATCC BAA-2314(T)  = DSM 25150(T)) is proposed as the type strain for the novel species. Phenotypic analysis of 26 independent isolates of C. vaccinii sp. nov. indicates that, despite close geographical and biological proximity, there is considerable metabolic diversity among individuals within the population.

  3. A coherent high-precision radiocarbon chronology for the Late-glacial sequence at Sluggan Bog, Co. Antrim, Northern Ireland

    NASA Astrophysics Data System (ADS)

    Lowe, J. J.; Walker, M. J. C.; Scott, E. M.; Harkness, D. D.; Bryant, C. L.; Davies, S. M.

    2004-02-01

    Seventy-five radiocarbon dates are presented from Sluggan Bog in Co. Antrim, Northern Ireland. The Holocene peats are underlain by Late-glacial sediments, which also appear to have accumulated largely in a mire environment. The radiocarbon dates, from the Late-glacial and early Holocene part of the profile, were obtained from the humic and humin fractions of the sedimentary matrix, and from plant macrofossils. The last-named were dated by AMS and the sediment samples by radiometric (beta counting) methods. Age-depth models for the three dating series show a very high level of agreement between the two fractions and the macrofossils. No statistically significant difference is found between the beta counting and AMS results. Three tephras were located in the profile, the uppermost of which is in a stratigraphical position suggestive of the Vedde Ash, but the geochemical and radiocarbon evidence do not support this interpretation. The lower ashes are in the correct stratigraphical position for the Laacher See and Borrobol tephras, attributions substantiated by the radiocarbon evidence, but not by the geochemical data. The Sluggan sequence has generated one of the most internally consistent radiocarbon chronologies for any Late-glacial site in the British Isles, and it is suggested that in future more effort should be devoted to the search for, and analysis of, Late-glacial mire sequences, rather than the limnic records that have formed the principal focus of Late-glacial investigations hitherto. Copyright

  4. Elevated Nitrogen Deposition from Alberta Oil Sands Development Stimulates Phosphatase Activity in Dominant Sphagnum Moss Species

    NASA Astrophysics Data System (ADS)

    Kashi, N. N.; Wieder, R.; Vile, M. A.

    2013-12-01

    Emissions of NOx associated with Alberta oil sands (AOS) development are leading to locally elevated atmospheric N deposition, in a region where background N deposition has been historically quite low (< 1 kg/ha/yr). This elevated N deposition has the potential to alter the ecosystem structure and function of nutrient-poor boreal peatlands. Nitrogen enrichment may alter soil microbial activity, which could be manifested in changes in extracellular enzyme activities. Since 2011, we have been experimentally adding N as NH4NO3 in simulated precipitation at 0, 5, 10, 15, 20, and 25 kg N ha/yr/ plus no-water controls to a boreal bog and a poor fen (3 replicate plots per treatment). In 2013, acid phosphatase activities in living plant capitulum of Sphagnum angustifolium, Sphagnum fuscum, and Sphagnum magellanicum were quantified in June and July using 4-methyumbelliferylphosphate and fluorescence detection of the enzymatically released methylumbelliferone (MUF). Phosphatase activities did not differ with N treatment for S. angustifolium in the bog (p=0.3409) or the poor fen (p=0.0629), or for S. fuscum in the bog (p=0.1950), averaging 35.0 × 0.7, 61.6 × 1.2, and 41.6 × 0.9 μmol MUF/g DWT/hr, respectively. For S. fuscum in the poor fen, phosphatase activities differed between N treatments (p=0.0275), ranging 40.6 × 1.1 μmol MUF/g DWT/hr in the control plots to 73.7 × 2.0 μmol MUF/g DWT/hr in the 5 kg/ha/yr N treatment plots; increasing N deposition did not result in a gradual change in enzyme activity. On the other hand, S. magellanicum phosphatase activities differed between N treatments (p=0.0189) and showed a pattern of generally increasing activity with increasing N deposition (37.4 × 0.5 μmol MUF/g DWT/hr in control plots; 97.9 × 4.5 μmol MUF/g DWT/hr in the 25 kg/ha/yr N treatment plots). The differing phosphatase responses between these dominant Sphagnum species suggest unique differences in nutrient balance and/or microbial activity. Combining the

  5. Evidence for differential effects of reduced and oxidised nitrogen deposition on vegetation independent of nitrogen load.

    PubMed

    van den Berg, Leon J L; Jones, Laurence; Sheppard, Lucy J; Smart, Simon M; Bobbink, Roland; Dise, Nancy B; Ashmore, Mike R

    2016-01-01

    Nitrogen (N) deposition impacts natural and semi-natural ecosystems globally. The responses of vegetation to N deposition may, however, differ strongly between habitats and may be mediated by the form of N. Although much attention has been focused on the impact of total N deposition, the effects of reduced and oxidised N, independent of the total N deposition, have received less attention. In this paper, we present new analyses of national monitoring data in the UK to provide an extensive evaluation of whether there are differences in the effects of reduced and oxidised N deposition across eight habitat types (acid, calcareous and mesotrophic grasslands, upland and lowland heaths, bogs and mires, base-rich mires, woodlands). We analysed data from 6860 plots in the British Countryside Survey 2007 for effects of total N deposition and N form on species richness, Ellenberg N values and grass:forb ratio. Our results provide clear evidence that N deposition affects species richness in all habitats except base-rich mires, after factoring out correlated explanatory variables (climate and sulphur deposition). In addition, the form of N in deposition appears important for the biodiversity of grasslands and woodlands but not mires and heaths. Ellenberg N increased more in relation to NHx deposition than NOy deposition in all but one habitat type. Relationships between species richness and N form were habitat-specific: acid and mesotrophic grasslands appear more sensitive to NHx deposition while calcareous grasslands and woodlands appeared more responsive to NOy deposition. These relationships are likely driven by the preferences of the component plant species for oxidised or reduced forms of N, rather than by soil acidification.

  6. Integrating the EMPD with an Alpine altitudinal training set to reconstruct climate variables in Holocene pollen records from high-altitude peat bogs

    NASA Astrophysics Data System (ADS)

    Furlanetto, Giulia; Badino, Federica; Brunetti, Michele; Champvillair, Elena; De Amicis, Mattia; Maggi, Valter; Pini, Roberta; Ravazzi, Cesare; Vallé, Francesca

    2016-04-01

    Temperatures and precipitation are the main environmental factors influencing vegetation and pollen production. Knowing the modern climate optima and tolerances of those plants represented in fossil assemblages and assuming that the relationships between plants and climate in the past are not dissimilar from the modern ones, fossil pollen records offer many descriptors to reconstruct past climate variables. The aim of our work is to investigate the potential of high-altitude pollen records from an Alpine peat bog (TBValter, close to the Ruitor Glacier, Western Italian Alps) for quantitative paleoclimate estimates. The idea behind is that high-altitude ecosystems are more sensitive to climate changes, especially to changes in July temperatures that severely affect the timberline ecotone. Meantime, we met with difficulties when considering the factors involved in pollen dispersal over a complex altitudinal mountain pattern, such as the Alps. We used the EMPD-European Modern Pollen Database (Davis et al., 2013) as modern training set to be compared with our high-altitude fossil site. The EMPD dataset is valuable in that it provides a large geographic coverage of main ecological and climate gradients (at sub-continental scale) but lacks in sampling of altitudinal gradients and high-altitude sites in the Alps. We therefore designed an independent altitudinal training set for the alpine valley hosting our fossil site. 27 sampling plots were selected along a 1700m-elevational transect. In a first step, each plot was provided with (i) 3 moss polsters collected following the guidelines provided by Cañellas-Boltà et al. (2009) and analyzed separately to account for differences in pollen deposition at small scale, (ii) morphometrical parameters obtained through a high-resolution DEM, and (iii) temperature and precipitation were estimated by means of weighted linear regression of the meteorological variable versus elevation, locally evaluated for each site (Brunetti et al

  7. Atmospheric mercury deposition recorded in an ombrotrophic peat core from Xiaoxing'an Mountain, Northeast China

    SciTech Connect

    Tang, Shunlin; Huang, Zhongwei; Liu, Jun; Yang, Zaichan; Lin, Qinhua

    2012-10-15

    The historical mercury accumulation rates (Hg AR) resulting from atmospheric deposition to Xiaoxing'an Mountain were determined via analysis of {sup 210}Pb- and {sup 14}C-dated cores up to 5000 years old. Natural Hg AR background, pre-industrial Hg AR and maximum industrial Hg AR in Northeast China were 2.2 {+-}1.0 {mu}g/m{sup 2}/yr for 5100-4500 BP, 5.7 {mu}g/m{sup 2}/yr and 112.4 {mu}g/m{sup 2}/yr, respectively. We assumed that the increase in Hg deposition in the Xiaoxing'an mountain area during industrial time was mainly attributed to local anthropogenic emissions around this peat bog.

  8. Alterations in the metabolic fingerprint of Cladonia portentosa in response to atmospheric nitrogen deposition.

    PubMed

    Freitag, Sabine; Hogan, Erika J; Crittenden, Peter D; Allison, Gordon G; Thain, Simon C

    2011-10-01

    Nitrogen availability has profound ecological consequences in nutrient-limited systems. In terrestrial settings these would include the upland heaths, sand dunes and blanket bogs of temperate latitudes. Understanding the physiological consequences of nitrogen enrichment is a first critical step in predicting possible consequences. Results are presented from a metabolic fingerprinting study using Fourier transform-infrared spectroscopy (FTIR) to detect biochemical differences in the lichen Cladonia portentosa collected from 25 sites across mainland Britain varying in their nitrogen input. Partial least-squares regression analysis of the FTIR data demonstrated that changes in broad biochemical classes were consistently correlated with mean annual wet inorganic nitrogen deposition loads. These results demonstrated a direct coupling of a broad range of metabolic processes in C. portentosa to nitrogen deposition.

  9. Seasonality of atmospheric nitrogen deposition at a semi-natural peatland site

    NASA Astrophysics Data System (ADS)

    Hurkuck, M.; Brümmer, C.; Kutsch, W. L.

    2012-04-01

    Large areas of natural peat bogs in Northwestern Germany have been converted to arable land and are characterised by decades of draining and peat cutting. Our study site - a semi-natural raised bog - is one of only very few remaining protected peatland areas. However, it is surrounded by highly fertilized agricultural land and poultry farms. In this study, we use a combined approach of independent methods to quantify seasonal variations of atmospheric nitrogen deposition most likely originated from agricultural practices. Concentrations and fluxes of ammonia and its atmospheric reactants are measured by a KAPS-denuder system integrated over one-week periods. Additionally, total nitrogen input from the atmosphere into a soil-plant model ecosystem is investigated by a 15N dilution method called 'Integrated Total Nitrogen Input' (ITNI). With this approach, we aim to allocate atmospheric nitrogen after its uptake by the ecosystem in aboveground biomass, roots and soil. First results from April to November 2011 show average ammonia concentrations ranging from 0.9 to 13.0 μg m-3. A first maximum of 8.8 μg m-3 could be observed in spring followed by relatively stable concentrations (mean: 3.7 μg m-3) in summer. Autumn ammonia concentrations reached a second peak of 13.0 μg m-3. By now, winter concentrations tend to be lower than those during the rest of the measuring period. Using the KAPS-denuder system within a gradient setup, deposition of ammonia was found to be between 0.08 to 0.25 kg NH3-N ha-1 week-1. The proportion of concentrations and fluxes of other N compounds such as HNO3, aerosol NH4 and NO3 was usually around 20 % of total measured nitrogen. During the first months of investigation, we found a total dry N deposition of about 5.4 kg ha-1. Extrapolation of data to one year amounts approximately to 9 kg ha-1 yr1. Our results suggest that the intensive agricultural land management of surrounding areas most likely leads to increasing N input into the

  10. Long-term impacts of peatland restoration on the net ecosystem exchange (NEE) of blanket bogs in Northern Scotland.

    NASA Astrophysics Data System (ADS)

    Hambley, Graham; Hill, Timothy; Saunders, Matthew; Arn Teh, Yit

    2016-04-01

    Unmanaged peatlands represent an important long-term C sink and thus play an important part of the global C cycle. Despite covering only 12 % of the UK land area, peatlands are estimated to store approximately 20 times more carbon than the UK's forests, which cover 13% of the land area. The Flow Country of Northern Scotland is the largest area of contiguous blanket bog in the UK, and one of the biggest in Europe, covering an area in excess of 4000 km2 and plays a key role in mediating regional atmospheric exchanges of greenhouse gases (GHGs) such as carbon dioxide (CO2), and water vapour (H2O). However, these peatlands underwent significant afforestation in the 1980s, when over 670 km2 of blanket bog were drained and planted with Sitka spruce (Picea sitchensis) and Lodgepole pine (Pinus contorta). This resulted in modifications to hydrology, micro-topography, vegetation and soil properties all of which are known to influence the production, emission and sequestration of key GHGs. Since the late 1990s restoration work has been carried out to remove forest plantations and raise water tables, by drain blocking, to encourage the recolonisation of Sphagnum species and restore ecosystem functioning. Here, we report findings of NEE and its constituent fluxes, GPP and Reco, from a study investigating the impacts of restoration on C dynamics over a chronosequence of restored peatlands. The research explored the role of environmental variables and microtopography in modulating land-atmosphere exchanges, using a multi-scale sampling approach that incorporated eddy covariance measurements with dynamic flux chambers. Key age classes sampled included an undrained peatland; an older restored peatland (17 years old); and a more recently restored site (12 years old). The oldest restored site showed the strongest uptake of C, with an annual assimilation rate of 858 g C m-2 yr-1 compared to assimilation rates of 501g C m-2 yr-1 and 575g C m-2 yr-1 from the younger restored site and

  11. Assessing the controls of the snow energy balance in a shrub-covered bog in eastern Ontario, Canada

    NASA Astrophysics Data System (ADS)

    Carey, S. K.; Knox, S.; Humphreys, E.

    2012-12-01

    The objectives of this study were to measure and evaluate the energy balance of a snowpack in a northern peatland, with a particular emphasis on the ground heat flux (G), and to evaluate the performance of a point energy and mass balance snowmelt model (SNOBAL) in peatland ecosystems. G is typically considered a small component of the snowpack energy balance (EB) when compared with radiative and turbulent fluxes. However, in environments where the soil temperature remains above freezing throughout the winter, G may be an important energy input to the snowpack. For direct assessment of the role of G in the snow energy budget of such an environment, the EB components of the snowpack at the Mer Bleue bog, a northern peatland, were directly measured and modelled using SNOBAL during the 2009-2010 winter. An 8 m tower mounted with a net radiometer, closed-path eddy covariance system, and supporting hydrometeorological instruments were used to quantify each form of energy transfer to the snowpack. In addition, snow surveys were conducted to determine snow depth, density, and snow water equivalent. When integrated over the pre-melt period, simulated and measured G proved to be a large contributor to the EB (25%). Net radiation and G were somewhat under-predicted by SNOBAL, whereas turbulent fluxes (especially latent heat fluxes, LE) were considerably over-predicted. G calculated by SNOBAL was found to be sensitive to the temperature gradient between the soil and the lower layer of the snowpack, whereas simulated turbulent fluxes were sensitive to the parameterization chosen to estimate roughness lengths for heat and water vapour.

  12. Initiation of Sphagnum moss hummocks in bogs and the presence of vascular plants: Is there a link?

    NASA Astrophysics Data System (ADS)

    Pouliot, Rémy; Rochefort, Line; Karofeld, Edgar; Mercier, Caroline

    2011-07-01

    Establishment of specific vascular plants and Sphagnum species, as well as asymmetrical competition and facilitation between the two types of plants are apparently important in the development of microtopography in peatlands. To determine whether peatland vascular plants can facilitate the initiation of Sphagnum hummocks, and consequently the differentiation of bog microtopography, we investigated the effects of vascular plant life form and structure on Sphagnum stem length and biomass. We showed that Sphagnum stem length and biomass were enhanced by low density of vascular plants and other introduced structures, which thus favoured hummock formation. Dense covers of vascular plants also promoted moss height growth, but the Sphagnum stems were etiolated and fluffy, their densities were too low and biomass was too small to initiate clear hummocks. We also showed that vascular plants contributed to microhabitats with stable temperatures and high relative humidity favourable to Sphagnum growth. Stress-gradient hypothesis, predicting that the relative frequencies of facilitation and competition events will vary inversely along abiotic stress gradients, could explain the nature of the interaction between mosses and vascular plants. At the onset of microstructures formation in peatlands, abiotic stress is probably more important and facilitation events could be frequent. Microclimatic effects of vascular plants may be essential for Sphagnum growth. Then, the presence of ericaceous shrubs or young trees enhances the microtopography by physically reinforcing the hummocks. During accentuation of microtopography, the positive interactions between Sphagnum mosses and vascular plants may be replaced by competition as abiotic stress declines. This study introduces new evidence for the role of vascular plants in the formation and maintenance of hummocks, especially under drier growing conditions.

  13. Sphagnum-dominated bog systems are highly effective yet variable sources of bio-available iron to marine waters.

    PubMed

    Krachler, Regina; Krachler, Rudolf F; Wallner, Gabriele; Steier, Peter; El Abiead, Yasin; Wiesinger, Hubert; Jirsa, Franz; Keppler, Bernhard K

    2016-06-15

    Iron is a micronutrient of particular interest as low levels of iron limit primary production of phytoplankton and carbon fluxes in extended regions of the world's oceans. Sphagnum-peatland runoff is extraordinarily rich in dissolved humic-bound iron. Given that several of the world's largest wetlands are Sphagnum-dominated peatlands, this ecosystem type may serve as one of the major sources of iron to the ocean. Here, we studied five near-coastal creeks in North Scotland using freshwater/seawater mixing experiments of natural creek water and synthetic seawater based on a (59)Fe radiotracer technique combined with isotopic characterization of dissolved organic carbon by Accelerator Mass Spectrometry. Three of the creeks meander through healthy Sphagnum-dominated peat bogs and the two others through modified peatlands which have been subject to artificial drainage for centuries. The results revealed that, at the time of sampling (August 16-24, 2014), the creeks that run through modified peatlands delivered 11-15μg iron per liter creek water to seawater, whereas the creeks that run through intact peatlands delivered 350-470μg iron per liter creek water to seawater. To find out whether this humic-bound iron is bio-available to marine algae, we performed algal growth tests using the unicellular flagellated marine prymnesiophyte Diacronema lutheri and the unicellular marine green alga Chlorella salina, respectively. In both cases, the riverine humic material provided a highly bio-available source of iron to the marine algae. These results add a new item to the list of ecosystem services of Sphagnum-peatlands. PMID:26971209

  14. Usual and unusual CIELAB color parameters for the study of peat organic matter properties: Tremoal do Pedrido bog (NW Spain)

    NASA Astrophysics Data System (ADS)

    Sanmartín, P.; Silva-Sánchez, N.; Martínez-Cortizas, A.; Prieto, B.

    2015-04-01

    We have tested the practical application of color measurements in the study of organic matter properties (C and N content, C/N ratios, degree of peat humification-DPH) of a 335 cm long peat core sampled at Tremoal do Pedrido bog. Usual and unusual CIELAB color parameters were measured on samples that were sectioned at high resolution (slices of 1 cm in thickness). The objective of the study is twofold: (i) describe a rapid, cost-effective and non-destructive method of assessing peat properties without the need of extractions and chemical methods and (ii) contribute to further research on applied colorimetry using the well-known CIELAB coordinates: L*, a*, b*, C*ab and hab (‘usual CIELAB color parameters’) and the less well-known CIELAB parameters: [a* x b*], [a*/b*], [(a*/b*) x 1000], [1000 x a*/(L*+ b*)], [2000 x a*/(L* x b*)] and RLab= [a*(a*2+b*2)1/2 1010]/(b* x L*6) (‘unusual CIELAB color parameters’). Our findings show that L* and hab coordinates as well as [(a*/b*) x 1000], [2000 x a*/(L* x b*)] and RLab parameters give the best bivariate Spearman's correlations. Linear regression equations were calculated to predict peat properties from all CIELAB parameters under study and a notable fit (R2: 0.65-0.79) was obtained. The evaluation presented here indicates that the determination of usual and unusual CIELAB parameters offers potential for the study of peat organic matter properties and encourages the routine application of this methodology on other peat cores and organic soils.

  15. Sphagnum can 'filter' N deposition, but effects on the plant and pore water depend on the N form.

    PubMed

    Chiwa, Masaaki; Sheppard, Lucy J; Leith, Ian D; Leeson, Sarah R; Tang, Y Sim; Cape, J Neil

    2016-07-15

    The ability of Sphagnum moss to efficiently intercept atmospheric nitrogen (N) has been assumed to be vulnerable to increased N deposition. However, the proposed critical load (20kgNha(-1)yr(-1)) to exceed the capacity of the Sphagnum N filter has not been confirmed. A long-term (11years) and realistic N manipulation on Whim bog was used to study the N filter function of Sphagnum (Sphagnum capillifolium) in response to increased wet N deposition. On this ombrotrophic peatland where ambient deposition was 8kgNha(-1)yr(-1), an additional 8, 24, and 56kgNha(-1)yr(-1) of either ammonium (NH4(+)) or nitrate (NO3(-)) has been applied for 11years. Nutrient status of Sphagnum and pore water quality from the Sphagnum layer were assessed. The N filter function of Sphagnum was still active up to 32kgNha(-1)yr(-1) even after 11years. N saturation of Sphagnum and subsequent increases in dissolved inorganic N (DIN) concentration in pore water occurred only for 56kgNha(-1)yr(-1) of NH4(+) addition. These results indicate that the Sphagnum N filter is more resilient to wet N deposition than previously inferred. However, functionality will be more compromised when NH4(+) dominates wet deposition for high inputs (56kgNha(-1)yr(-1)). The N filter function in response to NO3(-) uptake increased the concentration of dissolved organic N (DON) and associated organic anions in pore water. NH4(+) uptake increased the concentration of base cations and hydrogen ions in pore water though ion exchange. The resilience of the Sphagnum N filter can explain the reported small magnitude of species change in the Whim bog ecosystem exposed to wet N deposition. However, changes in the leaching substances, arising from the assimilation of NO3(-) and NH4(+), may lead to species change. PMID:27058130

  16. Ecophysiological adaptations of anaerobic bacteria to low pH: analysis of anaerobic digestion in acidic bog sediments. [Lactobacillus; Clostridium; Sarcina ventriculi

    SciTech Connect

    Goodwin, S.; Zeikus, G.J.

    1987-01-01

    The dynamics of anaerobic digestion were examined in the low-pH sediments of Crystal Bog in Wisconsin. The sediments (pH 4.9) contained 71% organic matter and the following concentrations of dissolved gases (micromoles per liter):CO/sub 2/, 1140; CH/sub 4/, 490; and H/sub 2/, 0.01. The rate of methane production was 6.2 ..mu..mol/liter of sediment per h, which is slower than eutrophic, neutral sediments. Microbial metabolic processes displayed the following pH optima: hydrolysis reactions, between 4.2 and 5.6; aceticlastic methanogenesis, 5.2; and hydrogen-consuming reactions, 5.6. The turnover rate constants for key intermediary metabolites were (h/sup -1/): glucose, 1.10; lactate, 0.277; acetate, 0.118; and ethanol, 0.089. The populations of anaerobes were low, with hydrolytic groups (10/sup 6//ml) several orders of magnitude higher than methanogens (10/sup 2//ml). The addition of carbon electron donors to the sediment resulted in the accumulation of hydrogen, whereas the addition of hydrogen resulted in the accumulation of fatty acids and the inhibition of hydrogen-producing acetogenic reactions. Strains of Lactobacillus, Clostridium, and Sarcina ventriculi were isolated from the bog, and their physiological attributes were characterized in relation to hydrolytic process functions in the sediments. The present studies provide evidence that the pH present in the bog sediments alter anaerobic digestion processes s, that total biocatalytic activity is lower bu the general carbon and electron flow pathways are similar to those of neutral anoxic sediments.

  17. Demographic and genetic status of an isolated population of bog turtles (Glyptemys muhlenbergii): Implications for managing small populations of long-lived animals

    USGS Publications Warehouse

    Pittman, Shannon E.; King, T.L.; Faurby, S.; Dorcas, M.E.

    2011-01-01

    In this study, we sought to determine the population stability and genetic diversity of one isolated population of the federally-threatened bog turtle (Glyptemys muhlenbergii) in North Carolina. Using capture-recapture data, we estimated adult survival and population growth rate from 1992 to 2007. We found that the population decreased from an estimated 36 adult turtles in 1994 to approximately 11 adult turtles in 2007. We found a constant adult survival of 0. 893 (SE = 0. 018, 95% confidence interval, 0. 853-0. 924) between 1992 and 2007. Using 18 microsatellite markers, we compared the genetic status of this population with five other bog turtle populations. The target population displayed allelic richness (4. 8 ?? 0. 5) and observed heterozygosity (0. 619 ?? 0. 064) within the range of the other bog turtle populations. Coalescent analysis of population growth rate, effective population size, and timing of population structuring event also indicated the genetics of the target population were comparable to the other populations studied. Estimates of effective population size were a proportion of the census size in all populations except the target population, in which the effective population size was larger than the census size (30 turtles vs. 11 turtles). We attribute the high genetic diversity in the target population to the presence of multiple generations of old turtles. This study illustrates that the demographic status of populations of long-lived species may not be reflected genetically if a decline occurred recently. Consequently, the genetic integrity of populations of long-lived animals experiencing rapid demographic bottlenecks may be preserved through conservation efforts effective in addressing demographic problems. ?? 2011 Springer Science+Business Media B.V.

  18. Dom Export from Coastal Temperate Bog Forest Watersheds to Marine Ecosystems: Improving Understanding of Watershed Processes and Terrestrial-Marine Linkages on the Central Coast of British Columbia

    NASA Astrophysics Data System (ADS)

    Oliver, A. A.; Giesbrecht, I.; Tank, S. E.; Hunt, B. P.; Lertzman, K. P.

    2014-12-01

    The coastal temperate bog forests of British Columbia, Canada, export high amounts of dissolved organic matter (DOM) relative to the global average. Little is known about the factors influencing the quantity and quality of DOM exported from these forests or the role of this terrestrially-derived DOM in near-shore marine ecosystems. The objectives of this study are to better understand patterns and controls of DOM being exported from bog forest watersheds and its potential role in near-shore marine ecosystems. In 2013, the Kwakshua Watershed Ecosystems Study at Hakai Beach Institute (Calvert Island, BC) began year-round routine collection and analysis of DOM, nutrients, and environmental variables (e.g. conductivity, pH, temperature, dissolved oxygen) of freshwater grab samples from the outlets of seven watersheds draining directly to the ocean, as well as near-shore marine samples adjacent to freshwater outflows. Dissolved organic carbon (DOC) varied across watersheds (mean= 11.45 mg L-1, sd± 4.22) and fluctuated synchronously with seasons and storm events. In general, higher DOC was associated with lower specific UV absorbance (SUVA254; mean= 4.59 L mg-1 m-1, sd± 0.55). The relationship between DOC and SUVA254 differed between watersheds, suggesting exports in DOM are regulated by individual watershed attributes (e.g. landscape classification, flow paths) as well as precipitation. We are using LiDAR and other remote sensing data to examine watershed controls on DOC export. At near-shore marine sites, coupled CTD (Conductivity Temperature Depth) and optical measures (e.g. spectral slopes, slope ratios (SR), EEMs), showed a clear freshwater DOM signature within the system following rainfall events. Ongoing work will explore the relationship between bog forest watershed attributes and DOM flux and composition, with implications for further studies on biogeochemical cycling, carbon budgets, marine food webs, and climate change.

  19. Uraniferous Phosphates: Resource, Security Risk, or Contaminant

    SciTech Connect

    LeMone, D.V.; Goodell, Ph.C.; Gibbs, S.G.; Winston, J.W.

    2008-07-01

    The escalation of the price of uranium (U) yellow cake (summer high = $130/0.454 kg (lb) has called into question the continuing availability of sufficient stockpiles and ores to process. As was developed during the years following World War II, the establishment and maintenance of a strategic inventory is a reasonable consideration for today. Therefore, it becomes critical to look at potential secondary resources beyond the classical ore suites now being utilized. The most economically viable future secondary source seems to be the byproducts of the beneficiation of phosphoric acids derived from phosphate ores. Phosphorous (P) is an essential nutrient for plants; its deficiency can result in highly restrictive limitations in crop productivity. Acidic soils in tropical and subtropical regions of the world are often P deficient with high P-sorption (fixation) capacities. To correct this deficiency, efficient water-soluble P fertilizers are required. The use of raw phosphate rocks not only adds phosphate but also its contained contaminants, including uranium to the treated land. Another immediate difficulty is phosphogypsum, the standard byproduct of simple extraction. It, for practical purposes, has been selectively classified as TENORM by regulators. The imposition of these standards presents major current and future disposal and re-utilization problems. Therefore, establishing an economically viable system that allows for uranium byproduct extraction from phosphoric acids is desirable. Such a system would be dependent on yellow cake base price stability, reserve estimates, political conditions, nation-state commitment, and dependence on nuclear energy. The accumulation of yellow cake from the additional extraction process provides a valuable commodity and allows the end acid to be a more environmentally acceptable product. The phosphogypsum already accumulated, as well as that which is in process, will not make a viable component for a radiation disposal devise (RDD). Concern for weapon proliferation by rogue nation states from the byproduct production of yellowcake is an unlikely scenario. To extract the fissile U-235 (0.07%) isotope from the yellowcake (99.3%) requires the erection of a costly major gaseous diffusion or a cascading centrifuge facility. Such a facility would be extremely difficult to mask. Therefore, from a diminished security risk and positive economic and environmental viewpoints, the utilization of a phosphoric acid beneficiation process extracting uranium is desirable. (authors)

  20. Antioxidant properties, phenolic composition and potentiometric sensor array evaluation of commercial and new blueberry (Vaccinium corymbosum) and bog blueberry (Vaccinium uliginosum) genotypes.

    PubMed

    Kraujalytė, Vilma; Venskutonis, Petras Rimantas; Pukalskas, Audrius; Česonienė, Laima; Daubaras, Remigijus

    2015-12-01

    Antioxidant properties of juices of newly bred and known blueberry (Vaccinium corymbosum) genotypes and wild bog blueberry (Vaccinium uliginosum) were evaluated by ABTS(+) scavenging capacity (RSC), ferric reducing antioxidant power (FRAP), oxygen radical absorbance capacity (ORAC), total phenolic content (TPC) and total anthocyanin content (TAC) assays. TPC varied in the range of 0.85-2.81 mg gallic acid equiv./mL, RSC, FRAP and ORAC values were 6.38-20.9, 3.07-17.8 and 4.21-45.68 μmol Trolox equiv./g, respectively. New blueberry genotypes and bog blueberry demonstrated stronger antioxidant properties and TAC than other studied genotypes. The content of quinic (203-3614 μg/mL), chlorogenic (20.0-346.8 μg/mL) acids and rutin (0.00-26.88 μg/mL) measured by UPLC/ESI-QTOF-MS varied depending on the genotype. Juices were evaluated by electronic tongue; PCA score plot showed that the method discriminates different genotypes although some juice samples were located very closely and overlapping. Significant differences were observed between L(∗), a(∗), b(∗) colour parameters of some genotypes. PMID:26041234

  1. Flourish or flush: effects of simulated extreme rainfall events on Sphagnum-dwelling testate amoebae in a subarctic bog (Abisko, Sweden).

    PubMed

    Tsyganov, Andrey N; Keuper, Frida; Aerts, Rien; Beyens, Louis

    2013-01-01

    Extreme precipitation events are recognised as important drivers of ecosystem responses to climate change and can considerably affect high-latitude ombrotrophic bogs. Therefore, understanding the relationships between increased rainfall and the biotic components of these ecosystems is necessary for an estimation of climate change impacts. We studied overall effects of increased magnitude, intensity and frequency of rainfall on assemblages of Sphagnum-dwelling testate amoebae in a field climate manipulation experiment located in a relatively dry subarctic bog (Abisko, Sweden). The effects of the treatment were estimated using abundance, species diversity and structure of living and empty shell assemblages of testate amoebae in living and decaying layers of Sphagnum. Our results show that increased rainfall reduced the mean abundance and species richness of living testate amoebae. Besides, the treatment affected species structure of both living and empty shell assemblages, reducing proportions of hydrophilous species. The effects are counterintuitive as increased precipitation-related substrate moisture was expected to have opposite effects on testate amoeba assemblages in relatively dry biotopes. Therefore, we conclude that other rainfall-related factors such as increased infiltration rates and frequency of environmental disturbances can also affect testate amoeba assemblages in Sphagnum and that hydrophilous species are particularly sensitive to variation in these environmental variables.

  2. Recovery of water tables in Welsh blanket bog after drain blocking: Discharge rates, time scales and the influence of local conditions

    NASA Astrophysics Data System (ADS)

    Wilson, Lorraine; Wilson, Jared; Holden, Joseph; Johnstone, Ian; Armstrong, Alona; Morris, Michael

    2010-09-01

    SummaryPeatland practitioners and scientists have increasingly recognised the damage resulting from various management methods, and the need to restore peatlands to achieve several potential benefits. Many of the hoped-for benefits of peatland restoration, such as Carbon storage, biodiversity conservation and water quality improvements, are thought to depend on a reinstatement of high water tables that had been reduced by drainage. Despite the current emphasis on restoring drained peatlands, many of the predicted responses to restoration are still not adequately proven and the mechanisms behind them still uncertain. This study reports on water table and discharge responses to drain blocking restoration of a degraded Welsh upland blanket bog. Restoration work and monitoring were designed to permit a novel catchment scale control-intervention experimental design. An information theoretic approach to examining the data provided evidence of increases in water retention and water tables within the bog after restoration. But the study also demonstrated the importance of small and large scale topography in determining the degree of these responses. The increases in water storage after restoration produced lower discharge rates observable at the level of both drains and hill streams; as well as greater water table stability, reduction in peak flows and increases in water residency after rainfall. Crucially, this study showed strong catchment scale differences in response, and a very gradual recovery of water tables, both of which highlight the need for more studies to be carried out at the landscape scale and over longer time periods.

  3. Groundwater flow with energy transport and water-ice phase change: Numerical simulations, benchmarks, and application to freezing in peat bogs

    USGS Publications Warehouse

    McKenzie, J.M.; Voss, C.I.; Siegel, D.I.

    2007-01-01

    In northern peatlands, subsurface ice formation is an important process that can control heat transport, groundwater flow, and biological activity. Temperature was measured over one and a half years in a vertical profile in the Red Lake Bog, Minnesota. To successfully simulate the transport of heat within the peat profile, the U.S. Geological Survey's SUTRA computer code was modified. The modified code simulates fully saturated, coupled porewater-energy transport, with freezing and melting porewater, and includes proportional heat capacity and thermal conductivity of water and ice, decreasing matrix permeability due to ice formation, and latent heat. The model is verified by correctly simulating the Lunardini analytical solution for ice formation in a porous medium with a mixed ice-water zone. The modified SUTRA model correctly simulates the temperature and ice distributions in the peat bog. Two possible benchmark problems for groundwater and energy transport with ice formation and melting are proposed that may be used by other researchers for code comparison. ?? 2006 Elsevier Ltd. All rights reserved.

  4. Antioxidant properties, phenolic composition and potentiometric sensor array evaluation of commercial and new blueberry (Vaccinium corymbosum) and bog blueberry (Vaccinium uliginosum) genotypes.

    PubMed

    Kraujalytė, Vilma; Venskutonis, Petras Rimantas; Pukalskas, Audrius; Česonienė, Laima; Daubaras, Remigijus

    2015-12-01

    Antioxidant properties of juices of newly bred and known blueberry (Vaccinium corymbosum) genotypes and wild bog blueberry (Vaccinium uliginosum) were evaluated by ABTS(+) scavenging capacity (RSC), ferric reducing antioxidant power (FRAP), oxygen radical absorbance capacity (ORAC), total phenolic content (TPC) and total anthocyanin content (TAC) assays. TPC varied in the range of 0.85-2.81 mg gallic acid equiv./mL, RSC, FRAP and ORAC values were 6.38-20.9, 3.07-17.8 and 4.21-45.68 μmol Trolox equiv./g, respectively. New blueberry genotypes and bog blueberry demonstrated stronger antioxidant properties and TAC than other studied genotypes. The content of quinic (203-3614 μg/mL), chlorogenic (20.0-346.8 μg/mL) acids and rutin (0.00-26.88 μg/mL) measured by UPLC/ESI-QTOF-MS varied depending on the genotype. Juices were evaluated by electronic tongue; PCA score plot showed that the method discriminates different genotypes although some juice samples were located very closely and overlapping. Significant differences were observed between L(∗), a(∗), b(∗) colour parameters of some genotypes.

  5. Lateglacial and early Holocene palaeoenvironmental 'events' in Sluggan Bog, Northern Ireland: comparisons with the Greenland NGRIP GICC05 event stratigraphy

    NASA Astrophysics Data System (ADS)

    Walker, Mike; Lowe, John; Blockley, Simon P. E.; Bryant, Charlotte; Coombes, Paul; Davies, Siwan; Hardiman, Mark; Turney, Chris S. M.; Watson, Jenny

    2012-03-01

    A multi-proxy Lateglacial environmental record is described from Sluggan Bog in County Antrim, Northern Ireland. Pollen, plant macrofossil, charcoal, sediment chemistry, stable isotope and sedimentological data provide a multi-faceted picture of local and regional environmental changes during the transition from the Last Cold Stage to the beginning of the present interglacial, and enable a series of distinctive palaeoenvironmental 'events' to be identified. A combination of radiometric and AMS radiocarbon dates on both humic and humin sediment fractions, and on charcoal fragments and plant macrofossils, provides one of the most closely-constrained radiocarbon timescales for any Lateglacial site in the British Isles. The evidence suggests that an initial period of warm conditions, beginning in the Sluggan record around 14.2 ka b2k (before AD 2000), and when open Salix-Betula woodland was locally present, was succeeded first by a heathland phase, then by a re-establishment of wood and scrub, before this was replaced during the later part of the Lateglacial (Woodgrange) Interstadial by species-rich grassland. In terms of timing, this sequence corresponds very closely to the GI-1e, GI-1d, GI-1c series of events in the Greenland NGRIP ice core. A short-lived Betula phase towards the end of the interstadial in the Sluggan sequence may reflect the short-lived climatic warming of GI-1a, although the radiocarbon age model suggests that it occurred prior to that event. There is a similar age discrepancy between the two sequences at the end of the interstadial with the onset of the Nahanagan (Younger Dryas) Stadial in Sluggan appearing to predate that in NGRIP by up to 200 yrs. By contrast, there is a very close correspondence between the date on the onset of the Holocene inferred from the pollen record in Sluggan (11.69 ka b2k) and the age of the Pleistocene-Holocene boundary (11.7 ka b2k) in NGRIP. While uncertainties remain over the climatic signals in the later

  6. The Effects of Peatland Plant Functional Types and Altered Hydrology on Porewater Chemistry in a Northern Bog

    NASA Astrophysics Data System (ADS)

    Daniels, A.; Kane, E. S.; Lilleskov, E. A.; Kolka, R. K.; Chimner, R. A.; Potvin, L. R.; Romanowicz, K. J.

    2012-12-01

    Northern wetlands, peatlands in particular, have been shown to store around 30% of the world's soil carbon and thus play a significant role in the carbon cycle of our planet. Carbon accumulation in peatlands is the result of retarded decomposition due to low oxygen availability in these water-logged environments. Changes in our planet's climate cycles are altering peatland hydrology and vegetation communities, resulting in changes in their ability to sequester carbon through increases in peat carbon oxidation and mineralization. To date, the consequences of altered hydrology and changes in vegetation communities, and their interactive effects on carbon storage, are not well understood. We have initiated a research plan that assesses the varying roles that water table variation and vegetation communities have on extracellular enzyme activity and labile carbon availability in porewater from an ombrotrophic bog. We assessed the effects of plant functional group (ericaceous shrubs, sedges, and bryophytes) and water table position on biogeochemical processes. Specifically, we measured dissolved organic carbon (DOC), total dissolved nitrogen (TDN), enzyme activity, organic acids, anions and cations, spectral indexes of aromaticity, and phenolic content in addressing our hypotheses of responses to climate change drivers. Research on these components will evaluate the relative importance of biology, water table, and their interactive affects on the porewater quality of peatlands. We hypothesized that oxygen availability will strongly influence decomposition in these systems but that this response will largely be mediated by changes in plant community and the enzymes associated with root exudates and mycorrhizae. To date, our data confirm vegetation and water table related patterns. Acetate and propionate concentrations in the sedge-dominated communities dropped significantly with depth and drainage, relative to the control and ericaceous treatments, which likely reflects

  7. Holocene climate dynamics in the Eastern Italian Alps: a multi-proxy study from ice and peat bogs

    NASA Astrophysics Data System (ADS)

    Poto, Luisa; Gabrieli, Jacopo; Segnana, Michela; Festi, Daniela; Oeggl, Klaus; Barbante, Carlo

    2014-05-01

    The Eastern Italian Alps are located near one of the areas in the world with some of the longest records of extreme environmental use by human activity. In this area, paleo-climate studies are hampered by the lack of high-resolution multi-proxy records with adequate chronological control. With this project, we propose to reconstruct Holocene climatic and environmental variations in the Eastern Italian Alps using terrestrial and glaciological archives. We aim to study the characteristics of different climate stages in this sector of the Alps using an ice core drilled on the top of the Ortles glacier (46°30' N, 10°32 E, 3850 m a.s.l.) and ombrotrophic peat bog records from the Dolomites (Danta di Cadore, 46°34' N, 12°33 E, 1400 m a.s.l. and Coltrondo 46°39'28.37''N 12°26'59.17''E, 1800 m a.s.l., Belluno province). The study of global climatic change require a holistic and multi-proxy approach to better understand several complex and often non-linear relationships. In the Italian Alps our study on peat cores represents the first attempt where a multi-proxy approach is applied, and here we report our first results. A 7.0 m peat sequence was extracted in Danta di Cadore. The depth-age scale, based upon independent 14C and 210Pb dates and modeled with the Clam method (Blaauw, 2010), demonstrates that the archive covers more than 13,200 years (cal BP). We determined physical proprieties, Ca and Ti trends, pore water pH, conductivity, and Ca/Mg ratios to identify changes in trophic conditions. The results confirm that the uppermost 400 cm are composed of ombrotrophic peat representing the longest Eastern Alpine ombrotrophic record yet obtained, covering the last 7,000 years. The oldest radiocarbon age (13,200 years cal BP) provides evidence that, during the Bölling-Alleröd interstadial, the upper part of the Piave Glacier was ice-free up to 1400 m a.s.l.. At that time pollen assemblages show that a conifer forest characterized the local vegetation. This forest was

  8. Nitrogen deposition and prey nitrogen uptake control the nutrition of the carnivorous plant Drosera rotundifolia.

    PubMed

    Millett, J; Foot, G W; Svensson, B M

    2015-04-15

    Nitrogen (N) deposition has important negative impacts on natural and semi-natural ecosystems, impacting on biotic interactions across trophic levels. Low-nutrient systems are particularly sensitive to changes in N inputs and are therefore more vulnerable to N deposition. Carnivorous plants are often part of these ecosystems partly because of the additional nutrients obtained from prey. We studied the impact of N deposition on the nutrition of the carnivorous plant Drosera rotundifolia growing on 16 ombrotrophic bogs across Europe. We measured tissue N, phosphorus (P) and potassium (K) concentrations and prey and root N uptake using a natural abundance stable isotope approach. Our aim was to test the impact of N deposition on D. rotundifolia prey and root N uptake, and nutrient stoichiometry. D. rotundifolia root N uptake was strongly affected by N deposition, possibly resulting in reduced N limitation. The contribution of prey N to the N contained in D. rotundifolia ranged from 20 to 60%. N deposition reduced the maximum amount of N derived from prey, but this varied below this maximum. D. rotundifolia tissue N concentrations were a product of both root N availability and prey N uptake. Increased prey N uptake was correlated with increased tissue P concentrations indicating uptake of P from prey. N deposition therefore reduced the strength of a carnivorous plant-prey interaction, resulting in a reduction in nutrient transfer between trophic levels. We suggest that N deposition has a negative impact on D. rotundifolia and that responses to N deposition might be strongly site specific. PMID:25655989

  9. Paleontological analysis of a lacustrine carbonaceous uranium deposit at the Anderson mine, Date Creek basin, west-central Arizona (U.S.A.)

    USGS Publications Warehouse

    Otton, J.K.; Bradbury, J.P.; Forester, R.M.; Hanley, J.H.

    1990-01-01

    The Tertiary sedimentary sequence of the Date Creek basin area of Arizona is composed principally of intertonguing alluvial-fan and lacustrine deposits. The lacustrine rocks contain large intermediate- to, locally, high-grade uranium deposits that form one of the largest uranium resources in the United States (an estimated 670,000 tons of U3O8 at an average grade of 0.023% is indicated by drilling to date). At the Anderson mine, about 50,000 tons of U3O8 occurs in lacustrine carbonaceous siltstones and mudstones (using a cutoff grade of 0.01%). The Anderson mine constitutes a new class of ore deposit, a lacustrine carbonaceous uranium deposit. Floral and faunal remains at the Anderson mine played a critical role in creating and documenting conditions necessary for uranium mineralization. Organic-rich, uraniferous rocks at the Anderson mine contain plant remains and ostracodes having remarkably detailed preservation of internal features because of infilling by opaline silica. This preservation suggests that the alkaline lake waters in the mine area contained high concentrations of dissolved silica and that silicification occurred rapidly, before compaction or cementation of the enclosing sediment. Uranium coprecipitated with the silica. Thinly laminated, dark-colored, siliceous beds contain centric diatoms preserved with carbonaceous material suggesting that lake waters at the mine were locally deep and anoxic. These alkaline, silica-charged waters and a stagnant, anoxic environment in parts of the lake were necessary conditions for the precipitation of large amounts of uranium in the lake-bottom sediments. Sediments at the Anderson mine contain plant remains and pollen that were derived from diverse vegetative zones suggesting about 1500 m of relief in the area at the time of deposition. The pollen suggests that the valley floor was semiarid and subtropical, whereas nearby mountains supported temperate deciduous forests. ?? 1990.

  10. Application of soil magnetometry on peat-bogs and soils in areas affected by historical and prehistoric ore mining and smelting.

    NASA Astrophysics Data System (ADS)

    Magiera, Tadeusz; Mendakiewicz, Maria; Szuszkiewicz, Marcin; Chrost, Leszak

    2015-04-01

    The valleys of upper Brynica and Stoła located in northern part of Upper Silesia were areas of historical human activities since prehistoric times. Historically confirmed mining and smelting of iron, silver and lead ores on this areas has been dated back to early Middle Ages, however recently some geochemical and radiometric analyses suggest even prehistoric time of such activities. The aim of this study was to check if it is possible to find any magnetic signal suggesting such activities in peat-bogs and soils of this area. This magnetic properties would be a result of presence of historical Technogenic Magnetic Particles (TMPs) arisen during the primitive smelting processes in the past. Many different types of TMPs were separated from the depth of 15-30 cm of soil profiles and also were present in deeper parts of peat-bogs accompanied by fine charcoal particles. The peat-bog horizons dated by radiocarbon (C14) for 2000 BC were contaminated by some heavy metals (Cu, Zn, Cd, Ag, Pb, Mn, Fe, Sr, Sc) and slightly increased magnetic susceptibility signal was also observed. On the base of soil surface magnetic measurement using MS2D Bartington sensor complemented by magnetic gradiometer system Grad 601-02 for the deeper soil penetration, some local magnetic anomalies were detected. In areas of local 'hot spots', the vertical cores up to 30 cm in depth were collected using the HUMAX core sampler. Vertical distribution of magnetic susceptibility along the cores was measured in the laboratory using the MS2C Bartington core sensor. The core section with increased susceptibility values were analyzed and TMPs were separated using a hand magnet. The separation of fine fraction of TMPs was carried out in an ultrasonic bath from the fine soil material suspended in isopropanol to avoid their coagulation. Irregular ceramic particles, ash and ore particles, as well as strong magnetic particles of metallic iron; all with diameter up to 10 mm and almost regular shape and rounded

  11. Differences in hydrophyte life forms induce spatial heterogeneity of CH4 production and its carbon isotopic signature in a temperate bog peatland

    NASA Astrophysics Data System (ADS)

    Itoh, Masayuki; Shimamura, Tetsuya; Ohte, Nobuhito; Takemon, Yasuhiro

    2015-07-01

    To clarify the effect of differences in hydrophyte life forms on methane (CH4) production and its carbon stable isotopic signature (δ13C-CH4), we analyzed CH4 and carbon dioxide (CO2) concentrations, their stable carbon isotope values, and chemical constituents dissolved in pore water in a small floating peat bog in Japan. Because eutrophication has modified the surrounding water quality, the bog vegetation on the mat has been, in part, replaced by fen-type vegetation. We hypothesized that differences in hydrophyte habitats affect redox conditions, including dissolved oxygen (DO) in water and therefore the amounts and carbon isotopic values of CH4 and CO2 dissolved in pore water. Between the habitats of two Sphagnum species, DO was considerably higher, and CH4 concentrations were significantly lower in Sphagnum cuspidatum Ehrh. habitats in hollow (DO: 0.62 ± 0.20 mg/L (standard error (SE)) and CH4: 0.18 ± 0.02 mmol/L) than in Sphagnum palustre L. habitats in hummock (DO: 0.29 ± 0.08 and CH4: 0.82 ± 0.06) in pore water (10 cm depth). Both DO and CH4 concentrations in three vascular plant habitats (Rhynchospora fauriei Franch., Phragmites australis [reed], and Menyanthes trifoliata L.) in pore water (10 cm depth) were intermediate relative to the two Sphagnum species. However, CH4 flux in M. trifoliata site was significantly higher than that at both Sphagnum sites, suggesting that the type of gas transport (diffusive or convective via root and stem) affected the depth profile of CH4 concentrations and its flux. δ13C-CH4 values in pore water also varied among the vegetation types, even within Sphagnum species (e.g., at 10 cm depth, δ13C-CH4: R. fauriei, -55.3 ± 1.8‰ (SE); P. australis, -57.5 ± 1.6‰; M. trifoliata, -56.7 ± 1.5‰; S. cuspidatum, -71.2 ± 1.4‰; and S. palustre, -60.4 ± 0.6‰). Our results suggest that significant differences arise in CH4 concentration and δ13C-CH4 values among the hydrophyte habitats even within a small peat bog and

  12. Small-scale spatial heterogeneity as a source for uncertainty of methane fluxes in an extensive near-natural bog-ecosystem

    NASA Astrophysics Data System (ADS)

    Hommeltenberg, J.; Schmid, H. P. E.; Bechtold, M.; Tiemeyer, B.

    2015-12-01

    Natural and restored peatlands are often a strong source of the greenhouse gas methane (CH4). CH4 fluxes vary greatly between different peatland ecosystems, depending on temperature, water level and vegetation. In addition, peatlands often show high small-scale spatial heterogeneity that strongly influences the magnitude of CH4 production. This heterogeneity potentially induce a sensor location bias and leads to additional uncertainties due to the flux footprint variability over heterogeneous terrain. To account for such uncertainty, we installed two eddy covariance towers 26 m apart (height: 6 m) to measure the CH4 flux, together with latent heat and CO2 fluxes at the bog ecosystem "Schechenfilz" in southern Germany. The study site is a large near-natural bog (111 ha) with heterogeneity that is characterized by patches of bog-pine forest, sedge meadows, peat mosses and open water areas. Ongoing CH4 measurements on one of the towers began in July 2012, and both towers were operated with a LI-7700 to measure the CH4 flux simultaneously from autumn 2014 to early spring 2015. In a second campaign, from mid-October to mid-November 2014, both instruments were operated at the same tower for comparison. Throughout the investigation, 17 water level gauges were used to measure the temporal variability of the water level in the mean footprint area. The water level was interpolated based on a high-resolution digital terrain model, which also allows us to account for the impact of the spatial variability of the water table. A vegetation map focused on the distribution of plants with aerenchymous tissues was used to determine the influence of the vegetation composition on the CH4 exchange. In this study, we estimated the uncertainty of CH4 fluxes induced by the instrument system and the flux footprint variability. The footprint analyses together with the water table measurements and vegetation map were also used to analyze the impact of small-scale spatial heterogeneity on the

  13. Multiple site study of recent atmospheric metal (Pb, Zn and Cu) deposition in the NW Iberian Peninsula using peat cores.

    PubMed

    Olid, Carolina; Garcia-Orellana, Jordi; Martínez-Cortizas, Antonio; Masqué, Pere; Peiteado-Varela, Eva; Sanchez-Cabeza, Joan-Albert

    2010-10-15

    In order to estimate atmospheric metal deposition in Southern Europe since the beginning of the Industrial Period (~1850 AD), concentration profiles of Pb, Zn and Cu were determined in four (210)Pb-dated peat cores from ombrotrophic bogs in Serra do Xistral (Galicia, NW Iberian Peninsula). Maximum metal concentrations varied by a factor of 1.8 for Pb and Zn (70 to 128μgg(-1) and 128 to 231μgg(-1), respectively) and 3.5 for Cu (11 to 37μgg(-1)). The cumulative metal inventories of each core varied by a factor of 3 for all analysed metals (132 to 329μgcm(-2) for Pb, 198 to 625μgcm(-2) for Zn and 22 to 69μgcm(-2) for Cu), suggesting differences in net accumulation rates among peatlands. Although results suggest that mean deposition rates vary within the studied area, the enhanced (210)Pb accumulation and the interpretation of the inventory ratios ((210)Pb/Pb, Zn/Pb and Cu/Pb) in two bogs indicated that either a record perturbation or post-depositional redistribution effects must be considered. After correction, Pb, Zn and Cu profiles showed increasing concentrations and atmospheric fluxes since the mid-XX(th) century to maximum values in the second half of the XX(th) century. For Pb, maximum fluxes were observed in 1955-1962 and ranged from 16 to 22mgm(-2)yr(-1) (mean of 18±1mgm(-2)yr(-1)), two orders of magnitude higher than in the pre-industrial period. Peaks in Pb fluxes in Serra do Xistral before the period of maximum consumption of leaded petrol in Europe (1970s-1980s) suggest the dominance of local pollutant sources in the area (i.e. coal mining and burning). More recent peaks were observed for Zn and Cu, with fluxes ranging from 32 to 52mgm(-2)yr(-1) in 1989-1996, and from 4 to 9mgm(-2)yr(-1) in 1994-2001, respectively. Our results underline the importance of multi-core studies to assess both the integrity and reliability of peat records, and the degree of homogeneity in bog accumulation. We show the usefulness of using the excess (210)Pb inventory to

  14. Export of dissolved organic carbon and nitrogen from drained and re-wetted bog sites in Lower Saxony (Germany)

    NASA Astrophysics Data System (ADS)

    Frank, Stefan; Tiemeyer, Bärbel; Freibauer, Annette

    2014-05-01

    Today, nearly all peatlands in Germany are drained for agriculture, forestry and peat cutting. The export of dissolved organic carbon (C) and nitrogen (N) may be important for the overall C and N balances and affects downstream ecosystems. While drainage generally increases solute losses, there is nearly no C and N export data of raised bogs in Germany which can be used to evaluate both the impact of drainage associated with intensive land use and the re-wetting of peat cutting sites. In the "Ahlenmoor" (North-Western Germany), four sampling points were chosen. Three sampling points represent a deeply drained intensively used grassland at various scales ranging from a drainage pipe (DP, 0.08 ha) and a drainage ditch (DD, 6.8 ha) to a collector ditch (CD, 20 ha). The fourth sampling point (RW) is a former peat cutting site (23 ha) re-wetted 10 years ago. At this site, polder technique was used to establish water tables at the soil surface. Sampling and discharge measurements were conducted bi-weekly from June 2011 to June 2013. Water table levels were recorded with automatic pressure sensors, and rating curves between discharge and water levels were used to calculate continuous discharge values. Samples were analyzed for dissolved organic carbon (DOC), particulate organic carbon (POC), dissolved organic nitrogen (DON), ammonium (NH4+), nitrate (NO3-), sulphate (SO42-), pH, electric conductivity (EC) and specific UV absorbance (SUVA). The discharge did not vary strongly between the sampling points and was slightly lower in the second year. Concentrations of all measured solutes were higher at the intensive grassland (DP, DD and CD) than at the re-wetted site. Surprisingly, SUVA showed no difference between all sites, while the DOC to DON ratio was narrower at DP, DD and CD than at RW. This indicates an export of more degraded dissolved organic matter (DOM) from the drained area. At the grassland sites, no statistical differences were found between the three scales

  15. Deposition head for laser

    DOEpatents

    Lewis, Gary K.; Less, Richard M.

    1999-01-01

    A deposition head for use as a part of apparatus for forming articles from materials in particulate form in which the materials are melted by a laser beam and deposited at points along a tool path to form an article of the desired shape and dimensions. The deposition head delivers the laser beam and powder to a deposition zone, which is formed at the tip of the deposition head. A controller comprised of a digital computer directs movement of the deposition zone along the tool path and provides control signals to adjust apparatus functions, such as the speed at which the deposition head moves along the tool path.

  16. Health assessment for Bog Creek Farm Site (BCFS) National Priorities List (NPL) site, Howell Township, Monmouth County, New Jersey, Region 2. CERCLIS No. NJD063157150. Final report

    SciTech Connect

    Not Available

    1989-04-10

    The Bog Creek Farm Site, located in a rural area of Howell Township, Monmouth County, New Jersey, is on the National Priorities List. In 1973 and 1974, various wastes were reportedly dumped at the site, including lacquer thinners, paint solvents and resins, disinfectants, animal carcasses, and residential debris. Sampling and analysis of on-site and off-site ground water, surface water, and sediments and of on-site waste and soil revealed several contaminants, primarily volatile organic compounds (VOCs), semi-volatile organic compounds, and heavy metals. Site contamination appears to be greatest immediately adjacent to an on-site waste-disposal trench. A potential public health threat exists from dermal absorption, ingestion, or inhalation of contamination from ground water, surface water, sediment, waste, and soil.

  17. Tundra in the rain: differential vegetation responses to three years of experimentally doubled summer precipitation in Siberian shrub and Swedish bog tundra.

    PubMed

    Keuper, Frida; Parmentier, Frans-Jan W; Blok, Daan; van Bodegom, Peter M; Dorrepaal, Ellen; van Hal, Jurgen R; van Logtestijn, Richard S P; Aerts, Rien

    2012-01-01

    Precipitation amounts and patterns at high latitude sites have been predicted to change as a result of global climatic changes. We addressed vegetation responses to three years of experimentally increased summer precipitation in two previously unaddressed tundra types: Betula nana-dominated shrub tundra (northeast Siberia) and a dry Sphagnum fuscum-dominated bog (northern Sweden). Positive responses to approximately doubled ambient precipitation (an increase of 200 mm year(-1)) were observed at the Siberian site, for B. nana (30 % larger length increments), Salix pulchra (leaf size and length increments) and Arctagrostis latifolia (leaf size and specific leaf area), but none were observed at the Swedish site. Total biomass production did not increase at either of the study sites. This study corroborates studies in other tundra vegetation types and shows that despite regional differences at the plant level, total tundra plant productivity is, at least at the short or medium term, largely irresponsive to experimentally increased summer precipitation.

  18. Deposit model for volcanogenic uranium deposits

    USGS Publications Warehouse

    Breit, George N.; Hall, Susan M.

    2011-01-01

    The International Atomic Energy Agency's tabulation of volcanogenic uranium deposits lists 100 deposits in 20 countries, with major deposits in Russia, Mongolia, and China. Collectively these deposits are estimated to contain uranium resources of approximately 500,000 tons of uranium, which amounts to 6 percent of the known global resources. Prior to the 1990s, these deposits were considered to be small (less than 10,000 tons of uranium) with relatively low to moderate grades (0.05 to 0.2 weight percent of uranium). Recent availability of information on volcanogenic uranium deposits in Asia highlighted the large resource potential of this deposit type. For example, the Streltsovskoye district in eastern Russia produced more than 100,000 tons of uranium as of 2005; with equivalent resources remaining. Known volcanogenic uranium deposits within the United States are located in Idaho, Nevada, Oregon, and Utah. These deposits produced an estimated total of 800 tons of uranium during mining from the 1950s through the 1970s and have known resources of 30,000 tons of uranium. The most recent estimate of speculative resources proposed an endowment of 200,000 tons of uranium.

  19. Uptake of radioiodide by Paenibacillus sp., Pseudomonas sp., Burkholderia sp. and Rhodococcus sp. isolated from a boreal nutrient-poor bog.

    PubMed

    Lusa, Merja; Lehto, Jukka; Aromaa, Hanna; Knuutinen, Jenna; Bomberg, Malin

    2016-06-01

    Radionuclides, like radioiodine ((129)I), may escape deep geological nuclear waste repositories and migrate to the surface ecosystems. In surface ecosystems, microorganisms can affect their movement. Iodide uptake of six bacterial strains belonging to the genera Paenibacillus, Pseudomonas, Burkholderia and Rhodococcus isolated from an acidic boreal nutrient-poor bog was tested. The tests were run in four different growth media at three temperatures. All bacterial strains removed iodide from the solution with the highest efficiency shown by one of the Paenibacillus strains with >99% of iodide removed from the solution in one of the used growth media. Pseudomonas, Rhodococcus and one of the two Paenibacillus strains showed highest iodide uptake in 1% yeast extract with maximum values for the distribution coefficient (Kd) ranging from 90 to 270L/kg DW. The Burkholderia strain showed highest uptake in 1% Tryptone (maximum Kd 170L/kg DW). The Paenibacillus strain V0-1-LW showed exceptionally high uptake in 0.5% peptone +0.25% yeast extract broth (maximum Kd>1,000,000L/kg DW). Addition of 0.1% glucose to the 0.5% peptone +0.25% yeast extract broth reduced iodide uptake at 4°C and 20°C and enhanced iodide uptake at 37°C compared to the uptake without glucose. This indicates that the uptake of glucose and iodide may be competing processes in these bacteria. We estimated that in in situ conditions of the bog, the bacterial uptake of iodide accounts for approximately 0.1%-0.3% of the total sorption of iodide in the surface, subsurface peat, gyttja and clay layers.

  20. Uptake of radioiodide by Paenibacillus sp., Pseudomonas sp., Burkholderia sp. and Rhodococcus sp. isolated from a boreal nutrient-poor bog.

    PubMed

    Lusa, Merja; Lehto, Jukka; Aromaa, Hanna; Knuutinen, Jenna; Bomberg, Malin

    2016-06-01

    Radionuclides, like radioiodine ((129)I), may escape deep geological nuclear waste repositories and migrate to the surface ecosystems. In surface ecosystems, microorganisms can affect their movement. Iodide uptake of six bacterial strains belonging to the genera Paenibacillus, Pseudomonas, Burkholderia and Rhodococcus isolated from an acidic boreal nutrient-poor bog was tested. The tests were run in four different growth media at three temperatures. All bacterial strains removed iodide from the solution with the highest efficiency shown by one of the Paenibacillus strains with >99% of iodide removed from the solution in one of the used growth media. Pseudomonas, Rhodococcus and one of the two Paenibacillus strains showed highest iodide uptake in 1% yeast extract with maximum values for the distribution coefficient (Kd) ranging from 90 to 270L/kg DW. The Burkholderia strain showed highest uptake in 1% Tryptone (maximum Kd 170L/kg DW). The Paenibacillus strain V0-1-LW showed exceptionally high uptake in 0.5% peptone +0.25% yeast extract broth (maximum Kd>1,000,000L/kg DW). Addition of 0.1% glucose to the 0.5% peptone +0.25% yeast extract broth reduced iodide uptake at 4°C and 20°C and enhanced iodide uptake at 37°C compared to the uptake without glucose. This indicates that the uptake of glucose and iodide may be competing processes in these bacteria. We estimated that in in situ conditions of the bog, the bacterial uptake of iodide accounts for approximately 0.1%-0.3% of the total sorption of iodide in the surface, subsurface peat, gyttja and clay layers. PMID:27266299

  1. Peat Bog Wildfire Smoke Exposure in Rural North Carolina Is Associated with Cardio-Pulmonary Emergency Department Visits

    EPA Science Inventory

    In June 2008 burning deposits of peat produced haze and air pollution far in excess of National Ambient Air Quality Standards, encroaching on rural communities of eastern North Carolina (NC). While the association of mortality and morbidity with exposure to urban air pollution i...

  2. Peat bog wildfire smoke exposure in rural North Carolina is associated with Cardiopulmonary emergency department visits assessed through syndromic surveillance

    EPA Science Inventory

    Background: In June 2008 burning deposits of peat produced haze and air pollution far in excess of National Ambient Air Quality Standards, encroaching on rural communities of eastern North Carolina (NC). While the association of mortality and morbidity with exposure to urban air ...

  3. Peat Bog Wildfire Smoke Exposure in Rural North Carolina Is Associated with Cardiopulmonary Emergency Department Visits Assessed Through Syndromic Surveillance

    EPA Science Inventory

    In June 2008 burning deposits of peat produced haze and air pollution far in excess of National Ambient Air Quality Standards, encroaching on rural communities of eastern North Carolina (NC). While the association of mortality and morbidity with exposure to urban air pollution is...

  4. Geochronology and Fluid-Rock Interaction Associated with the Nopal I Uranium Deposit, Pena Blanca, Mexico

    SciTech Connect

    M. Fayek; P. Goodell; M. Ren; A. Simmons

    2005-07-11

    The Nopal I uranium (U) deposit, Pena Blanca District, Mexico, largely consists of secondary U{sup 6+} minerals, which occur within a breccia pipe mainly hosted by the 44 Ma Nopal and Colorados volcanic formations. These two units overly the Pozos conglomerate formation and Cretaceous limestone. Three new vertical diamond drill holes (DDHs) were recently drilled at Nopal I. DDH-PB1 with continuous core was drilled through the Nopal I deposit and two additional DDHs were drilled {approx}50 m on either side of the cored hole. These DDHs terminate 20 m below the current water table, thus allowing the detection of possible gradients in radionuclide contents resulting from transport from the overlying uranium deposit. Primary uraninite within the main ore body is rare and fine-grained ({approx}50 micrometers), thus making geochronology of the Nopal I deposit very difficult. Uranium, lead and oxygen isotopes can be used to study fluid-uraninite interaction, provided that the analyses are obtained on the micro-scale. Secondary ionization mass spectrometry (SIMS) permits in situ measurement of isotopic ratios with a spatial resolution on the scale of a few {micro}m. Preliminary U-Pb results show that uraninite from the main ore body gives an age of 32 {+-} 8 Ma, whereas uraninite from the uraniferous Pozos conglomerate that lies nearly 100 m below the main ore body and 25 meters above the water table, gives a U-Pb age that is <1 Ma. Oxygen isotopic analyses show that uraninite from the ore body has a {delta}{sup 18}O = -10.8{per_thousand}, whereas the uraninite within the Pozos conglomerate has a {delta}{sup 18}O = +1.5{per_thousand}. If it is assumed that both uraninites precipitated from meteoric water ({delta}{sup 18}O = -7{per_thousand}), then calculated precipitation temperatures are 55 C for the uraninite from the ore body and 20 C for uraninite hosted by the Pozos conglomerate. These temperatures are consistent with previous studies that calculated precipitation

  5. The impact of 90 years of drainage works on some chemical properties of raised peat bog organic soils - case study from valley of the Upper San river in Polish Bieszczady Mts. (Eastern Carpathians).

    NASA Astrophysics Data System (ADS)

    Stolarczyk, Mateusz

    2016-04-01

    Wetland ecosystems, including raised peat bogs are characterized by a specific water conditions and unique vegetation, which makes peatland highly important habitats due to protection of biodiversity. Transformation of peat bog areas is particularly related to changes in the environment e.g. according to reclamation works. Drainage of peatlands is directly associated to the decrease of groundwater levels and lead to a number of changes in the chemical and physical properties of peat material, included contents of exchangeable cations in the surface layers of peat soils in the decession phase of peat development and release above compounds from the soil to ground or surface waters. The aim of the research was to determine the impact of extended drainage works on chemical composition of sorption complex of raised peat bog organic soils and identification the potential environmental effects of alkaline cations leaching to the surface waters. Research was carried out on the peat bogs located in the Upper San valley in Polish Bieszczady Mts. (Eastern Carpathians). Soil samples used in this study were collected from 3 soil profiles in 10 or 20 cm intervals to the approximately 130 cm depth. Laboratory analyses included determination of basic properties of organic material such as the degree of peat decomposition, ash content, soil pH and carbon, hydrogen, nitrogen concentrations. Additionally the amount of alkaline cations, exchangeable and extractable acidity was determined. Furthermore, the degree of saturation of the sorption complex with alkaline cations (V) and cation exchange capacity (CEC) are calculated. In order to evaluate the impact of the examined peat bog to the environment, also water samples were collected and ions composition was measured. The obtained results show that studied organic soils are oligotrophic and strongly acidic. In the case of organic material related to decession phase of peat development, as a result of the lengthy drainage works

  6. Origin and depositional environment of clastic deposits in the Hilo drill hole, Hawaii

    USGS Publications Warehouse

    Beeson, M.H.; Clague, D.A.; Lockwood, J.P.

    1996-01-01

    Volcaniclastic units cored at depths of about 87, 164, 178, 226, and 246 m below sea level and carbonate units located between depths of 27 and 53 m below sea level in the Hilo drill core were found to be deposited at or near sea level. Four of these units are hydroclastic deposits, formed when subaerially erupted Mauna Loa lava flows entered the ocean and fragmented to produce quenched, glassy fragments during hydrovolcanic explosions. Ash units 24 and 26, at 178 m depth, accumulated at sea level in a freshwater bog. They contain pyroxenes crystallized from tholeiitic magma that we infer erupted explosively at the summit of Kilauea volcano. Two carbon-rich layers from these ashes have a weighted average radiocarbon age of 38.6 ?? 0.9 ka; the ashes probably correlate with the oldest and thickest part of the Pahala ash. Ash unit 44, at the transition from Mauna Kea to Mauna Loa lava flows, was probably nearly 3.2 m thick and is inferred to be equivalent to the lower thick part of the composite Homelani ash mapped in Hilo and on the flanks of Mauna Kea. The age of this part of Homelani ash is between 128 ?? 33 and 200 ?? 10 ka; it may have erupted subglacially during the Pohakuloa glacial maxima on Mauna Kea. Beach sand units 12 and 22 were derived from nearby Mauna Loa and Mauna Kea lava flows. The middle of beach sand unit 38 was derived mainly from lava erupted near the distal end of the subaerial east rift zone of Kilauea volcano; these sands were transported about 33 km northwest to Hilo Bay by prevailing longshore currents. Combined age, depth, and sea level markers in the core allow us to determine that lava flow recurrence intervals averaged one flow every 4 kyr during the past 86 kyr and one flow every 16 kyr between 86 and 200 ka at the drill site and that major explosive eruptions that deposit thick ash in Hilo have occurred only twice in the last 400 kyr. These recurrence intervals support the moderate lava flow hazard zonation (zone 3) for coastal Hilo

  7. Origin and depositional environment of clastic deposits in the Hilo drill hole, Hawaii

    NASA Astrophysics Data System (ADS)

    Beeson, M. H.; Clague, D. A.; Lockwood, J. P.

    1996-05-01

    Volcaniclastic units cored at depths of about 87, 164, 178, 226, and 246 m below sea level and carbonate units located between depths of 27 and 53 m below sea level in the Hilo drill core were found to be deposited at or near sea level. Four of these units are hydroclastic deposits, formed when subaerially erupted Mauna Loa lava flows entered the ocean and fragmented to produce quenched, glassy fragments during hydrovolcanic explosions. Ash units 24 and 26, at 178 m depth, accumulated at sea level in a freshwater bog. They contain pyroxenes crystallized from tholeiitic magma that we infer erupted explosively at the summit of Kilauea volcano. Two carbon-rich layers from these ashes have a weighted average radiocarbon age of 38.6 ± 0.9 ka; the ashes probably correlate with the oldest and thickest part of the Pahala ash. Ash unit 44, at the transition from Mauna Kea to Mauna Loa lava flows, was probably nearly 3.2 m thick and is inferred to be equivalent to the lower thick part of the composite Homelani ash mapped in Hilo and on the flanks of Mauna Kea. The age of this part of Homelani ash is between 128 ± 33 and 200 ± 10 ka; it may have erupted subglacially during the Pohakuloa glacial maxima on Mauna Kea. Beach sand units 12 and 22 were derived from nearby Mauna Loa and Mauna Kea lava flows. The middle of beach sand unit 38 was derived mainly from lava erupted near the distal end of the subaerial east rift zone of Kilauea volcano; these sands were transported about 33 km northwest to Hilo Bay by prevailing longshore currents. Combined age, depth, and sea level markers in the core allow us to determine that lava flow recurrence intervals averaged one flow every 4 kyr during the past 86 kyr and one flow every 16 kyr between 86 and 200 ka at the drill site and that major explosive eruptions that deposit thick ash in Hilo have occurred only twice in the last 400 kyr. These recurrence intervals support the moderate lava flow hazard zonation (zone 3) for coastal Hilo

  8. Uranium and organic matters: use of pyrolysis-gas chromatography, carbon, hydrogen, and uranium contents to characterize the organic matter from sandstone-type deposits

    USGS Publications Warehouse

    Leventhal, Joel S.

    1979-01-01

    Organic matter seems to play an important role in the genesis of uranium deposits in sandstones in the western United States. Organic materials associated with ore from the Texas coastal plain, Tertiary basins of Wyoming, Grants mineral belt of New Mexico, and the Uravan mineral belt of Utah and Colorado vary widely in physical appearance and chemical composition. Partial characterization of organic materials is achieved by chemical analyses to determine atomic hydrogen-to-carbon (H/C) ratios and by gas chromatographic analyses to determine the molecular fragments evolved during stepwise pyrolysis. From the pyrolysis experiments the organic materials can be classified and grouped: (a) lignites from Texas and Wyoming and (b) hydrogen poor materials, from Grants and Uravan mineral belts and Wyoming; (c) naphthalene-containing materials from Grants mineral belt and Wyoming; and (d) complex and aromatic materials from Uravan, Grants and Wyoming. The organic materials analyzed have atomic H/C ratios that range from approximately 0.3 to at least 1.5. The samples with higher H/C ratios yield pyrolysis products that contain as many as 30 carbon atoms per molecule. Samples with low H/C ratios are commonly more uraniferous and yield mostly methane and low-molecular-weight gases during pyrolysis.

  9. Cascadia Tsunami Deposit Database

    USGS Publications Warehouse

    Peters, Robert; Jaffe, Bruce; Gelfenbaum, Guy; Peterson, Curt

    2003-01-01

    The Cascadia Tsunami Deposit Database contains data on the location and sedimentological properties of tsunami deposits found along the Cascadia margin. Data have been compiled from 52 studies, documenting 59 sites from northern California to Vancouver Island, British Columbia that contain known or potential tsunami deposits. Bibliographical references are provided for all sites included in the database. Cascadia tsunami deposits are usually seen as anomalous sand layers in coastal marsh or lake sediments. The studies cited in the database use numerous criteria based on sedimentary characteristics to distinguish tsunami deposits from sand layers deposited by other processes, such as river flooding and storm surges. Several studies cited in the database contain evidence for more than one tsunami at a site. Data categories include age, thickness, layering, grainsize, and other sedimentological characteristics of Cascadia tsunami deposits. The database documents the variability observed in tsunami deposits found along the Cascadia margin.

  10. Deposition of Atmospheric Pollutants

    NASA Astrophysics Data System (ADS)

    Malet, L. M.

    Deposition of Atmospheric Pollutants, containing the proceedings of a colloquium held at Oberursel/Taunus, FRG, November 9-11, 1981, is divided into three main parts: dry deposition; wet deposition; and deposition on plants and vegetation.The 20 articles in the volume permit a fair survey of present-day knowledge and will be a useful tool to all working on the topic. Pollution by deposition of either the dry or wet sort is very insidious; its importance only appears in the long range, when its effects are or are almost irreversible. That is why concern was so long in emerging from decision makers.

  11. Dust is the dominant source of "heavy metals" to peat moss (Sphagnum fuscum) in the bogs of the Athabasca Bituminous Sands region of northern Alberta.

    PubMed

    Shotyk, William; Bicalho, Beatriz; Cuss, Chad W; Duke, M John M; Noernberg, Tommy; Pelletier, Rick; Steinnes, Eiliv; Zaccone, Claudio

    2016-01-01

    Sphagnum fuscum was collected from twenty-five ombrotrophic (rain-fed) peat bogs surrounding open pit mines and upgrading facilities of Athabasca Bituminous Sands (ABS) in northern Alberta (AB) in order to assess the extent of atmospheric contamination by trace elements. As a control, this moss species was also collected at a bog near Utikuma (UTK) in an undeveloped part of AB and 264km SW of the ABS region. For comparison, this moss was also collected in central AB, in the vicinity of the City of Edmonton which is approximately 500km to the south of the ABS region, from the Wagner Wetland which is 22km W of the City, from Seba Beach (ca. 90km W) and from Elk Island National Park (ca. 45km E). All of the moss samples were digested and trace elements concentrations determined using ICP-SMS at a commercial laboratory, with selected samples also analyzed using instrumental neutron activation analysis at the University of Alberta. The mosses from the ABS region yielded lower concentrations of Ag, As, Bi, Cd, Cu, Pb, Sb, Tl, and Zn compared to the moss from the Edmonton area. Concentrations of Ni and Mo in the mosses were comparable in these two regions, but V was more abundant in the ABS samples. Compared with the surface vegetation of eight peat cores collected in recent years from British Columbia, Ontario, Quebec and New Brunswick, the mean concentrations of Ag, As, Bi, Cd, Cu, Mo, Ni, Pb, Sb, Tl and Zn in the mosses from the ABS region are generally much lower. In fact, the concentrations of these trace elements in the samples from the ABS region are comparable to the corresponding values in forest moss from remote regions of central and northern Norway. Lithophile element concentrations (Ba, Be, Ga, Ge, Li, Sc, Th, Ti, Zr) explain most of the variation in trace metal concentrations in the moss samples. The mean concentrations of Th and Zr are greatest in the moss samples from the ABS region, reflecting dust inputs to the bogs from open pit mines, aggregate

  12. Carbon dioxide flux and net primary production of a boreal treed bog: Responses to warming and water-table-lowering simulations of climate change

    NASA Astrophysics Data System (ADS)

    Munir, T. M.; Perkins, M.; Kaing, E.; Strack, M.

    2015-02-01

    Midlatitude treed bogs represent significant carbon (C) stocks and are highly sensitive to global climate change. In a dry continental treed bog, we compared three sites: control, recent (1-3 years; experimental) and older drained (10-13 years), with water levels at 38, 74 and 120 cm below the surface, respectively. At each site we measured carbon dioxide (CO2) fluxes and estimated tree root respiration (Rr; across hummock-hollow microtopography of the forest floor) and net primary production (NPP) of trees during the growing seasons (May to October) of 2011-2013. The CO2-C balance was calculated by adding the net CO2 exchange of the forest floor (NEff-Rr) to the NPP of the trees. From cooler and wetter 2011 to the driest and the warmest 2013, the control site was a CO2-C sink of 92, 70 and 76 g m-2, the experimental site was a CO2-C source of 14, 57 and 135 g m-2, and the drained site was a progressively smaller source of 26, 23 and 13 g CO2-C m-2. The short-term drainage at the experimental site resulted in small changes in vegetation coverage and large net CO2 emissions at the microforms. In contrast, the longer-term drainage and deeper water level at the drained site resulted in the replacement of mosses with vascular plants (shrubs) on the hummocks and lichen in the hollows leading to the highest CO2 uptake at the drained hummocks and significant losses in the hollows. The tree NPP (including above- and below-ground growth and litter fall) in 2011 and 2012 was significantly higher at the drained site (92 and 83 g C m-2) than at the experimental (58 and 55 g C m-2) and control (52 and 46 g C m-2) sites. We also quantified the impact of climatic warming at all water table treatments by equipping additional plots with open-top chambers (OTCs) that caused a passive warming on average of ~ 1 °C and differential air warming of ~ 6 °C at midday full sun over the study years. Warming significantly enhanced shrub growth and the CO2 sink function of the drained

  13. Sphagnum-dwelling testate amoebae in subarctic bogs are more sensitive to soil warming in the growing season than in winter: the results of eight-year field climate manipulations.

    PubMed

    Tsyganov, Andrey N; Aerts, Rien; Nijs, Ivan; Cornelissen, Johannes H C; Beyens, Louis

    2012-05-01

    Sphagnum-dwelling testate amoebae are widely used in paleoclimate reconstructions as a proxy for climate-induced changes in bogs. However, the sensitivity of proxies to seasonal climate components is an important issue when interpreting proxy records. Here, we studied the effects of summer warming, winter snow addition solely and winter snow addition together with spring warming on testate amoeba assemblages after eight years of experimental field climate manipulations. All manipulations were accomplished using open top chambers in a dry blanket bog located in the sub-Arctic (Abisko, Sweden). We estimated sensitivity of abundance, diversity and assemblage structure of living and empty shell assemblages of testate amoebae in the living and decaying layers of Sphagnum. Our results show that, in a sub-arctic climate, testate amoebae are more sensitive to climate changes in the growing season than in winter. Summer warming reduced species richness and shifted assemblage composition towards predominance of xerophilous species for the living and empty shell assemblages in both layers. The higher soil temperatures during the growing season also decreased abundance of empty shells in both layers hinting at a possible increase in their decomposition rates. Thus, although possible effects of climate changes on preservation of empty shells should always be taken into account, species diversity and structure of testate amoeba assemblages in dry subarctic bogs are sensitive proxies for climatic changes during the growing season.

  14. Sphagnum-dwelling testate amoebae in subarctic bogs are more sensitive to soil warming in the growing season than in winter: the results of eight-year field climate manipulations.

    PubMed

    Tsyganov, Andrey N; Aerts, Rien; Nijs, Ivan; Cornelissen, Johannes H C; Beyens, Louis

    2012-05-01

    Sphagnum-dwelling testate amoebae are widely used in paleoclimate reconstructions as a proxy for climate-induced changes in bogs. However, the sensitivity of proxies to seasonal climate components is an important issue when interpreting proxy records. Here, we studied the effects of summer warming, winter snow addition solely and winter snow addition together with spring warming on testate amoeba assemblages after eight years of experimental field climate manipulations. All manipulations were accomplished using open top chambers in a dry blanket bog located in the sub-Arctic (Abisko, Sweden). We estimated sensitivity of abundance, diversity and assemblage structure of living and empty shell assemblages of testate amoebae in the living and decaying layers of Sphagnum. Our results show that, in a sub-arctic climate, testate amoebae are more sensitive to climate changes in the growing season than in winter. Summer warming reduced species richness and shifted assemblage composition towards predominance of xerophilous species for the living and empty shell assemblages in both layers. The higher soil temperatures during the growing season also decreased abundance of empty shells in both layers hinting at a possible increase in their decomposition rates. Thus, although possible effects of climate changes on preservation of empty shells should always be taken into account, species diversity and structure of testate amoeba assemblages in dry subarctic bogs are sensitive proxies for climatic changes during the growing season. PMID:21839679

  15. Handbook on surficial uranium deposits. Chapter 3. World distribution relative to climate and physical setting

    SciTech Connect

    Carlisle, D

    1983-01-01

    This chapter discusses regional controls which affect the world distribution of surficial chemogenic uranium deposits. The most important of these are (1) climate, (2) geomorphology, including physiographic and climatic stability, and (3) provenance, i.e., the weathering terrain from which uranium and associated substances are derived. The three economically important environments are the calcrete environment, simple evaporative environments and paludal environments. Of these three categories, the calcrete uranium environment is probably the most uniquely constrained in terms of regional climate, geomorphic setting, provenance (vanadium as well as uranium) and especially the need for long term stability of both climate and physiography. Purely evaporative deposits, though subject to some of the same kinds of constraints, can also reflect local circumstances and a wider range of climates, physiographic settings, and source terrains. The third category encompassing bogs, marshes and organic-rich playas can form under an even wider range of climates and settings provided only that organic materials accumulate in abundance and are contacted by uranium-bearing waters. For all of these reasons and also because of the great economic importance of the calcrete environment as well as its relative novelty and complexity the discussion in this chapter is focused on calcrete, dolocrete and gypcrete uranium deposits. Objective data are reviewed first follwed by inferences and suggestions. 13 figures.

  16. Effects of rewetting on greenhouse gas emissions in different microtopes in a cut-over drained bog in Schleswig-Holstein, Germany

    NASA Astrophysics Data System (ADS)

    Vybornova, Olga; Pfeiffer, Eva-Maria; Kutzbach, Lars

    2016-04-01

    In peatlands, all biogeochemical processes and the amount of exported carbon and nitrogen compounds are strongly influenced by changes in the water table. Peatland drainage leads to increased peat oxidization and changes peatlands from carbon sinks to net carbon sources. Especially, the emissions of the important greenhouse gases (GHG) carbon dioxide, methane and nitrous oxide are increased due to drainage. The currently ongoing restoration in the bog Himmelmoor (N 53° 44'20", E 9° 51'00", Quickborn) with an extent of about 6 km2 one of the largest raised bogs in Schleswig-Holstein, offers the possibility to characterize and to document the development of the fluxes at different sites before, during and after rewetting, using a method of small-scale closed chambers. Six subsites with differing water level and land use were identified: an area that was rewetted 30 years ago with Sphagnum vegetation, an area rewetted in 2009, an area with on-going peat extraction, deep peat cutting ditches refilled with peat with and without Eriophorum angustifolium vegetation and a comparatively dry peat dam. We determined that in the course of years 2014-2015 the measured N2O and CO2 fluxes varied between -0,1 and 1,9 mg m‑2 h‑1 and between -0,12 and 1,09 g m‑2 h‑1, respectively, and the highest nitrous oxide as well as carbon dioxide fluxes are typical for the dry peat dam study site. The measured CH4 fluxes were between -1,8 and 22,7 mg m‑2 h‑1, where the highest rates were found on the area rewetted 30 years ago and on the peat cutting ditches with Eriophorum angustifolium. Accounting for the different global warming potentials (GWP) of the measured greenhouse gases, the annual GHG balance was calculated. Emissions from all study sites ranged between 5,2 and 36 t CO2-eq ha‑1 year‑1 and were dominated by high emissions of CO2 (2,5 up to 25,5 t CO2-eq ha‑1 year‑1). Highest emission rates were found at the dry peat dam site and at the area rewetted 30 years

  17. Effects of rewetting on greenhouse gas emissions in different microtopes in a cut-over drained bog in Schleswig-Holstein, Germany

    NASA Astrophysics Data System (ADS)

    Vybornova, Olga; Pfeiffer, Eva-Maria; Kutzbach, Lars

    2016-04-01

    In peatlands, all biogeochemical processes and the amount of exported carbon and nitrogen compounds are strongly influenced by changes in the water table. Peatland drainage leads to increased peat oxidization and changes peatlands from carbon sinks to net carbon sources. Especially, the emissions of the important greenhouse gases (GHG) carbon dioxide, methane and nitrous oxide are increased due to drainage. The currently ongoing restoration in the bog Himmelmoor (N 53° 44'20", E 9° 51'00", Quickborn) with an extent of about 6 km2 one of the largest raised bogs in Schleswig-Holstein, offers the possibility to characterize and to document the development of the fluxes at different sites before, during and after rewetting, using a method of small-scale closed chambers. Six subsites with differing water level and land use were identified: an area that was rewetted 30 years ago with Sphagnum vegetation, an area rewetted in 2009, an area with on-going peat extraction, deep peat cutting ditches refilled with peat with and without Eriophorum angustifolium vegetation and a comparatively dry peat dam. We determined that in the course of years 2014-2015 the measured N2O and CO2 fluxes varied between -0,1 and 1,9 mg m-2 h-1 and between -0,12 and 1,09 g m-2 h-1, respectively, and the highest nitrous oxide as well as carbon dioxide fluxes are typical for the dry peat dam study site. The measured CH4 fluxes were between -1,8 and 22,7 mg m-2 h-1, where the highest rates were found on the area rewetted 30 years ago and on the peat cutting ditches with Eriophorum angustifolium. Accounting for the different global warming potentials (GWP) of the measured greenhouse gases, the annual GHG balance was calculated. Emissions from all study sites ranged between 5,2 and 36 t CO2-eq ha-1 year-1 and were dominated by high emissions of CO2 (2,5 up to 25,5 t CO2-eq ha-1 year-1). Highest emission rates were found at the dry peat dam site and at the area rewetted 30 years ago. The peat dams and

  18. Effects of extreme experimental drought and rewetting on CO2 and CH4 exchange in mesocosms of 14 European peatlands with different nitrogen and sulfur deposition.

    PubMed

    Estop-Aragonés, Cristian; Zając, Katarzyna; Blodau, Christian

    2016-06-01

    The quantitative impact of intense drought and rewetting on gas exchange in ombrotrophic bogs is still uncertain. In particular, we lack studies investigating multitudes of sites with different soil properties and nitrogen (N) and sulfur (S) deposition under consistent environmental conditions. We explored the timing and magnitude of change in CO2 (Respiration, Gross Primary Production - GPP, and Net Exchange - NE) and CH4 fluxes during an initial wet, a prolonged dry (~100 days), and a subsequent wet period (~230 days) at 12 °C in 14 Sphagnum peat mesocosms collected in hollows from bogs in the UK, Ireland, Poland, and Slovakia. The relationship of N and S deposition with GPP, respiration, and CH4 exchange was investigated. Nitrogen deposition increased CO2 fluxes and GPP more than respiration, at least up to about 15 kg N ha(-1)  yr(-1) . All mesocosms became CO2 sources during drying and most of them when the entire annual period was considered. Response of GPP to drying was faster than that of respiration and contributed more to the change in NE; the effect was persistent and few sites recovered "predry" GPP by the end of the wet phase. Respiration was higher during the dry phase, but did not keep increasing as WT kept falling and peaked within the initial 33 days of drying; the change was larger when differences in humification with depth were small. CH4 fluxes strongly peaked during early drought and water table decline. After rewetting, methanogenesis recovered faster in dense peats, but CH4 fluxes remained low for several months, especially in peats with higher inorganic reduced sulfur content, where sulfate was generated and methanogenesis remained suppressed. Based on a range of European sites, the results support the idea that N and S deposition and intense drought can substantially affect greenhouse gas exchange on the annual scale.

  19. Ages of 24 widespread tephras erupted since 30,000 years ago in New Zealand, with re-evaluation of the timing and palaeoclimatic implications of the Lateglacial cool episode recorded at Kaipo bog

    NASA Astrophysics Data System (ADS)

    Lowe, David J.; Blaauw, Maarten; Hogg, Alan G.; Newnham, Rewi M.

    2013-08-01

    Tephras are important for the NZ-INTIMATE project because they link all three records comprising the composite inter-regional stratotype developed for the New Zealand climate event stratigraphy (NZ-CES). Here we firstly report new calendar ages for 24 widespread marker tephras erupted since 30,000 calendar (cal.) years ago in New Zealand to help facilitate their use as chronostratigraphic dating tools for the NZ-CES and for other palaeoenvironmental and geological applications. The selected tephras comprise 12 rhyolitic tephras from Taupo, nine rhyolitic tephras from Okataina, one peralkaline rhyolitic tephra from Tuhua, and one andesitic tephra each from Tongariro and Egmont/Taranaki volcanic centres. Age models for the tephras were obtained using three methods: (i) 14C-based wiggle-match dating of wood from trees killed by volcanic eruptions (these dates published previously); (ii) flexible depositional modelling of a high-resolution 14C-dated age-depth sequence at Kaipo bog using two Bayesian-based modelling programs, Bacon and OxCal's P_Sequence function, and the IntCal09 data set (with SH offset correction -44 ± 17 yr); and (iii) calibration of 14C ages using OxCal's Tau_Boundary function and the SHCal04 and IntCal09 data sets. Our preferred dates or calibrated ages for the 24 tephras are as follows (youngest to oldest, all mid-point or mean ages of 95% probability ranges): Kaharoa AD 1314 ± 12; Taupo (Unit Y) AD 232 ± 10; Mapara (Unit X) 2059 ± 118 cal. yr BP; Whakaipo (Unit V) 2800 ± 60 cal. yr BP; Waimihia (Unit S) 3401 ± 108 cal. yr BP; Stent (Unit Q) 4322 ± 112 cal. yr BP; Unit K 5111 ± 210 cal. yr BP; Whakatane 5526 ± 145 cal. yr BP; Tuhua 6577 ± 547 cal. yr BP; Mamaku 7940 ± 257 cal. yr BP; Rotoma 9423 ± 120 cal. yr BP; Opepe (Unit E) 9991 ± 160 cal. yr BP; Poronui (Unit C) 11,170 ± 115 cal. yr BP; Karapiti (Unit B) 11,460 ± 172 cal. yr BP; Okupata 11,767 ± 192 cal. yr BP; Konini (bed b) 11,880 ± 183 cal. yr BP; Waiohau 14,009 ± 155

  20. Airfoil deposition model

    NASA Technical Reports Server (NTRS)

    Kohl, F. J.

    1982-01-01

    The methodology to predict deposit evolution (deposition rate and subsequent flow of liquid deposits) as a function of fuel and air impurity content and relevant aerodynamic parameters for turbine airfoils is developed in this research. The spectrum of deposition conditions encountered in gas turbine operations includes the mechanisms of vapor deposition, small particle deposition with thermophoresis, and larger particle deposition with inertial effects. The focus is on using a simplified version of the comprehensive multicomponent vapor diffusion formalism to make deposition predictions for: (1) simple geometry collectors; and (2) gas turbine blade shapes, including both developing laminar and turbulent boundary layers. For the gas turbine blade the insights developed in previous programs are being combined with heat and mass transfer coefficient calculations using the STAN 5 boundary layer code to predict vapor deposition rates and corresponding liquid layer thicknesses on turbine blades. A computer program is being written which utilizes the local values of the calculated deposition rate and skin friction to calculate the increment in liquid condensate layer growth along a collector surface.

  1. Lipid D/H Ratios from Multiple Sources and Deposits Indicate Drier Little Ice Age at Washington Island (4°43`N, 160°25`W), Central Pacific

    NASA Astrophysics Data System (ADS)

    Muegler, I.; Sachse, D.; Sachs, J. P.

    2010-12-01

    To compare the sensitivity of biomarker D/H ratios from two distinct climate archives, a lake and a peat bog on the Tropical Pacific Island of Terrania, compound-specific hydrogen isotope ratios (expressed as δD values) were determined on lipid biomarkers from various biological sources deposited in the two climate archives. At present, Terrania or Washington Island (4°43`N, 160°25`W) permanently lies in the intertropical convergence zone (ITCZ) and receives an annual precipitation of 2,903 mm. The interior of this lens shaped island contains a freshwater lake and peat bogs. Previous studies on the lake sediments found evidence for a substantially drier climate at times during the Little Ice Age (AD 1400-1850) based on the lithologic transition from modern freshwater sediments to a sequence of pure cyanobacterial mat in concert with δD values from total lipid extracts (Sachs et al., 2009). Here we report on δD values from lipids of various sources: dinoflagellate algae (dinosterol and a saturated C30 sterol (4α -methyl-24-ethyl-5α -cholestan-3β-ol), microbial sources (diploptene and nC21 alkane) and higher plants (fern-7-ene, β-sitosterol and stigmastanol). Mean δD values from all lipids, measured in both archives, are significantly enriched in deuterium by between 22 and 86‰ during previously inferred drier climate conditions and simultaneously record the transition towards a freshwater lake at around AD1550. Measured δD values of all lipids cover a wide range from -281‰ to -105‰ during freshwater deposition and from -185‰ to -50‰ when climate was drier. In agreement with the observed isotopic difference between lipids produced via the acetogenic and the mevalonic acid biosynthetic pathway δD values for algae and higher plant sterols are depleted in deuterium relative to the nC21 alkane by 150‰ on average. The consistent δD values from dinosterol and 4α -methyl-24-ethyl-5α -cholestan-3β-ol from the lake and peat deposits signify the

  2. Ionized cluster beam deposition

    NASA Astrophysics Data System (ADS)

    Kirkpatrick, A. R.

    1983-11-01

    Ionized Cluster Beam (ICB) deposition, a new technique originated by Takagi of Kyoto University in Japan, offers a number of unique capabilities for thin film metallization as well as for deposition of active semiconductor materials. ICB allows average energy per deposited atom to be controlled and involves impact kinetics which result in high diffusion energies of atoms on the growth surface. To a greater degree than in other techniques, ICB involves quantitative process parameters which can be utilized to strongly control the characteristics of films being deposited. In the ICB deposition process, material to be deposited is vaporized into a vacuum chamber from a confinement crucible at high temperature. Crucible nozzle configuration and operating temperature are such that emerging vapor undergoes supercondensation following adiabatic expansion through the nozzle.

  3. Ionized cluster beam deposition

    NASA Technical Reports Server (NTRS)

    Kirkpatrick, A. R.

    1983-01-01

    Ionized Cluster Beam (ICB) deposition, a new technique originated by Takagi of Kyoto University in Japan, offers a number of unique capabilities for thin film metallization as well as for deposition of active semiconductor materials. ICB allows average energy per deposited atom to be controlled and involves impact kinetics which result in high diffusion energies of atoms on the growth surface. To a greater degree than in other techniques, ICB involves quantitative process parameters which can be utilized to strongly control the characteristics of films being deposited. In the ICB deposition process, material to be deposited is vaporized into a vacuum chamber from a confinement crucible at high temperature. Crucible nozzle configuration and operating temperature are such that emerging vapor undergoes supercondensation following adiabatic expansion through the nozzle.

  4. Anthropogenic impacts in North Poland over the last 1300 years--a record of Pb, Zn, Cu, Ni and S in an ombrotrophic peat bog.

    PubMed

    De Vleeschouwer, François; Fagel, Nathalie; Cheburkin, Andriy; Pazdur, Anna; Sikorski, Jaroslaw; Mattielli, Nadine; Renson, Virginie; Fialkiewicz, Barbara; Piotrowska, Natalia; Le Roux, Gaël

    2009-10-15

    Lead pollution history over Northern Poland was reconstructed for the last ca. 1300 years using the elemental and Pb isotope geochemistry of a dated Polish peat bog. The data show that Polish Pb-Zn ores and coal were the main sources of Pb, other heavy metals and S over Northern Poland up until the industrial revolution. After review of the potential mobility of each element, most of the historical interpretation was based on Pb and Pb isotopes, the other chemical elements (Zn, Cu, Ni, S) being considered secondary indicators of pollution. During the last century, leaded gasoline also contributed to anthropogenic Pb pollution over Poland. Coal and Pb-Zn ores, however, remained important sources of pollution in Eastern European countries during the last 50 years, as demonstrated by a high (206)Pb/(207)Pb ratio (1.153) relative to that of Western Europe (ca. 1.10). The Pb data for the last century were also in good agreement with modelled Pb inventories over Poland and the Baltic region. PMID:19683332

  5. Landscape dynamics and fire activity since 6740 cal yr BP in the Cantabrian region (La Molina peat bog, Puente Viesgo, Spain)

    NASA Astrophysics Data System (ADS)

    Pérez-Obiol, R.; García-Codron, J. C.; Pèlachs, A.; Pérez-Haase, A.; Soriano, J. M.

    2016-03-01

    A lack of paleobotanic studies with adequate resolution and multiproxy approaches has limited proper discussion of vegetation dynamics in Cantabria and of the role of fires in the configuration of the plant landscape during the Holocene in the northwest part of the Iberian peninsula. The pollen diagram of La Molina peat bog in Puente Viesgo (43°15‧38″ N-3°58‧37″ W; ETRS89), located at 484 m.a.s.l., and the study of its sedimentary charcoals allowed the acquisition of a continuous and thorough fire sequence for the last 6700 cal yr BP and an understanding of its relationship to the forest. The results show the importance of human influence on the incidence and characteristics of fire activity during the different phases studied: the Neolithic, Bronze Age, Iron Age, Roman period, and Middle Ages. A synergy seems to exist between dry climate periods (especially during Bond events 3 and 4) and a greater presence of biomass. As the Holocene advances, vegetation coverage clearly tends to decrease. This study provides key elements for understanding the role of fire activity in the forest dynamics of deciduous and evergreen Quercus, Corylus, Pinus, Fagus, and Alnus and demonstrates the strongly artificialized character of the present landscape.

  6. A late Holocene record of trace metal deposition in lake sediments near Quelccaya Ice Cap, Peru

    NASA Astrophysics Data System (ADS)

    Beal, S. A.; Kelly, M. A.; Jackson, B. P.; Osterberg, E. C.; Stroup, J. S.; Baker, R. A.

    2010-12-01

    Records of atmospheric metal deposition have been used extensively in the Northern Hemisphere to examine historical events ranging from the evolution of ancient metallurgy to climatic change. Establishing such a record in tropical South America is pertinent due to ongoing questions about the metallurgical history of pre-colonial Andean civilizations, recent atmospheric pollution levels, and late Holocene climate variability. Here we present a late Holocene record of the Ag, As, Cd, Co, Cu, Hg, Ni, Pb, Sr, Zn, and Pb isotopic compositions of atmospheric deposition from three 1.5 m-long lake cores and one 5 m-long bog core recovered near Quelccaya Ice Cap (13.9 °S), in the southeastern Peruvian Andes. The bog core, representing deposition from the present to at least 2415 yr BP, records relatively stable concentrations of As, Co, Cu, Hg, Ni, Pb, Sr, and Zn between 2415 (±78) and 916 (±29) yr BP. However, Ag and Cd exhibit brief gradual enrichments over background levels by factors of 6 and 11, respectively, shortly after 2415 (±78) yr BP as a possible result of ancient metallurgy. Sometime following the 916 (±29) yr BP date, Ag, As, Cd, Cu, Hg, Ni, Pb, and Sr abruptly become enriched by factors of 10, 37, 11, 11, 47, 6, 16, and 24, respectively, possibly from anthropogenic sources and/or the 1600 AD eruption of Huaynaputina in southern Peru. These enrichments are concurrent with a shift in 206Pb/207Pb to 1.182 from background levels of 1.213 (±0.002, n=20). A subsequent quiescent period in metal concentrations is marked by a brief return to background 206Pb/207Pb values, followed by erratic 206Pb/207Pb values yet decreased metal concentrations in the most recent sediments. Only Hg is enriched over background levels, by a factor of 3, in the most recent sediment. Forthcoming higher-resolution data from the three lake cores will utilize pre-industrial lead isotope ratios and Ti, Zr, and REE fluxes to examine past variability of the El Niño-Southern Oscillation

  7. Investigation of freshwater sponges spicules deposits in a karstic lake in Brazil.

    PubMed

    Machado, V S; Volkmer-Ribeiro, C; Iannuzzi, R

    2016-02-01

    The environmental conditions which contributed to the formation of the notorious quaternary deposits of freshwater sponge spicules in karstic lentic environments in Brazil have been subject of some speculation. No investigation has yet been conducted to test whether these deposits currently originate in karstic lakes. To provide for such an investigation, Serra Negra Lake, which is formed on an ultramafic-alkaline-carbonatite dome at central western Brazil, close to the area of occurrence of the paleo-deposits was selected for the study. Bottom sediments were sampled at 10 stations across the lake, and water was sampled at five of the stations, in June/2011 (rainy season) and October/2011 (dry season). Analysis of granulometry, organic matter and presence of spicules were carried out in the sediments. Lake water was analysed for the main physical and chemical characteristics. Deposit of spicules was restricted to the northern area of the lake, which is rich in macrophyte. The taxonomic analysis of the spicules indicated the contribution of five sponge species, Dosilia pydanieli, Metania spinata, Radiospongilla amazonensis, Trochospongilla variabilis and Heterorotula fistula, which formed large deposits in neighbouring areas. The high silica concentration, derived from the dome volcanic rocks, constant water level and available substrate are credited for the continuous production of sponges and spicules, confirmed by the rare presence of gemmoscleres. The lake is classed as a minerotrophic fen type of bog with a heavy contribution from the surrounding creeks. Lake sediments are fine with high levels of organic matter and peat, which contributed to the trapping of spicules in the sediments. PMID:26909621

  8. Domestic phosphate deposits

    USGS Publications Warehouse

    McKelvey, V.E.; Cathcart, J.B.; Altschuler, Z.S.; Swanson, R.W.; Lutz, Katherine

    1953-01-01

    Most of the worlds phosphate deposits can be grouped into six types: 1) igneous apatite deposits; 2) marine phosphorites; 3) residual phosphorites; 4) river pebble deposits; 5) phosphatized rock; and 6) guano. The igneous apatites and marine phosphorites form deposits measurable in millions or billions of tons; the residual deposits are measurable in thousands or millions; and the other types generally only in thousands of tons. Igneous apatite deposits have been mined on a small scale in New York, New Jersey, and Virginia. Marine phosphorites have been mined in Montana, Idaho, Utah, Wyoming, Arkansas, Tennessee, North Carolina, South Carolina, Georgia, and Florida. Residual phosphorites have been mined in Tennessee, Pennsylvania, and Florida. River pebble has been produced in South Carolina and Florida; phosphatized rock in Tennessee and Florida; and guano in New Mexico and Texas. Present production is limited almost entirely to Florida, Tennessee, Montana, Idaho, and Wyoming. Incomplete but recently partly revised estimates indicate the presence of about 5 billion tons of phosphate deposits in the United States that is minable under present economic conditions. Deposits too lean in quality or thickness to compete with those in the western and southeastern fields probably contain tens of billions of tons.

  9. Radionuclide deposition control

    DOEpatents

    Brehm, William F.; McGuire, Joseph C.

    1980-01-01

    The deposition of radionuclides manganese-54, cobalt-58 and cobalt-60 from liquid sodium coolant is controlled by providing surfaces of nickel or high nickel alloys to extract the radionuclides from the liquid sodium, and by providing surfaces of tungsten, molybdenum or tantalum to prevent or retard radionuclide deposition.

  10. Role of Organic Solutes in the Chemistry Of Acid-Impacted Bog Waters of the Western Czech Republic

    NASA Astrophysics Data System (ADS)

    HrušKa, Jakub; Johnson, Chris E.; KráM, Pavel

    1996-04-01

    In many regions, naturally occurring organic acid anions can effectively buffer mineral acid inputs from atmospheric deposition, moderating their effect on surface water pH. We studied the effect of chronically high inputs of acid rain on the chemistry of three brown-water streams in the western Czech Republic. The dissolved organic acids in the streams were similar in character to those of other systems in Europe and North America. The site densities (the carboxyl group content per mass of C) were similar to values reported from Fenno-Scandia, and the relationship between the apparent pKa and pH conformed to those from two North American studies. Sulfate and organic acid anions (OA-) were the dominant anions in all three streams, yet despite high dissolved organic carbon and total organic acid concentrations, OA - comprised only 21-32% of total anion charge. This pattern was due to very high sulfate concentrations and, in two of the streams, a low degree of dissociation of the organic acids, probably the results of high long-term inputs of strong acids. Stream water pH was highly correlated to sulfate concentration, but uncorrelated with OA-, suggesting that free acidity is controlled by strong mineral acids rather than organic acids. Thus future reductions in strong acid inputs should result in increased pH and a return to organic control over acid-base chemistry.

  11. Pre-industrial accumulation of anthropogenic polycyclic aromatic hydrocarbons found in a blanket bog of the Iberian Peninsula.

    PubMed

    Pontevedra-Pombal, Xabier; Rey-Salgueiro, Ledicia; García-Falcón, Mercedes S; Martínez-Carballo, Elena; Simal-Gándara, Jesús; Martínez-Cortizas, Antonio

    2012-07-01

    Studies on the temporal deposition of polycyclic aromatic hydrocarbons (PAHs) in peatlands are scarce, and none have been carried out in the Iberian Peninsula. To address this gap, ten PAHs were determined in a short peat core (spanning the last 1000 years) sampled in NW Iberian Peninsula, by HPLC-fluorescence. Fluoranthene, pyrene, benzo[b]fluoranthene and indeno[1,2,3-cd]pyrene predominated in the upper layers (10 cm), whereas fluoranthene and pyrene were the most abundant in the lower layers (40 cm), which showed an absence of high molecular weight PAHs (benzo[ghi]perylene and Indeno[1,2,3-cd]pyrene). Although increased PAH contents have been detected since 1700 A.D., coinciding with the beginning of the Metallurgical and Industrial Revolution, high levels of fluoranthene and pyrene were present in peat samples dating back to the 12th century A.D. The results suggest that changes in sources, type of emission (global or local) and transport could be responsible for the different PAH content and composition of the peat core. These changes are consistent with the history of the use of natural resources in the NW of the Iberian Peninsula. PMID:22578810

  12. Biomimetic thin film deposition

    SciTech Connect

    Rieke, P.R.; Graff, G.E.; Campbell, A.A.; Bunker, B.C.; Baskaran, S.; Song, L.; Tarasevich, B.J.; Fryxell, G.E.

    1995-09-01

    Biological mineral deposition for the formation of bone, mollusk shell and other hard tissues provides materials scientists with illustrative materials processing strategies. This presentation will review the key features of biomineralization and how these features can be of technical importance. We have adapted existing knowledge of biomineralization to develop a unique method of depositing inorganic thin films and coating. Our approach to thin film deposition is to modify substrate surfaces to imitate the proteins found in nature that are responsible for controlling mineral deposition. These biomimetic surfaces control the nucleation and growth of the mineral from a supersaturated aqueous solution. This has many processing advantages including simple processing equipment, environmentally benign reagents, uniform coating of highly complex shapes, and enhanced adherence of coating. Many different types of metal oxide, hydroxide, sulfide and phosphate materials with useful mechanical, optical, electronic and biomedical properties can be deposited.

  13. Solution deposition assembly

    SciTech Connect

    Roussillon, Yann; Scholz, Jeremy H; Shelton, Addison; Green, Geoff T; Utthachoo, Piyaphant

    2014-01-21

    Methods and devices are provided for improved deposition systems. In one embodiment of the present invention, a deposition system is provided for use with a solution and a substrate. The system comprises of a solution deposition apparatus; at least one heating chamber, at least one assembly for holding a solution over the substrate; and a substrate curling apparatus for curling at least one edge of the substrate to define a zone capable of containing a volume of the solution over the substrate. In another embodiment of the present invention, a deposition system for use with a substrate, the system comprising a solution deposition apparatus; at heating chamber; and at least assembly for holding solution over the substrate to allow for a depth of at least about 0.5 microns to 10 mm.

  14. Stratiform chromite deposit model

    USGS Publications Warehouse

    Schulte, Ruth F.; Taylor, Ryan D.; Piatak, Nadine M.; Seal, Robert R., II

    2010-01-01

    Stratiform chromite deposits are of great economic importance, yet their origin and evolution remain highly debated. Layered igneous intrusions such as the Bushveld, Great Dyke, Kemi, and Stillwater Complexes, provide opportunities for studying magmatic differentiation processes and assimilation within the crust, as well as related ore-deposit formation. Chromite-rich seams within layered intrusions host the majority of the world's chromium reserves and may contain significant platinum-group-element (PGE) mineralization. This model of stratiform chromite deposits is part of an effort by the U.S. Geological Survey's Mineral Resources Program to update existing models and develop new descriptive mineral deposit models to supplement previously published models for use in mineral-resource and mineral-environmental assessments. The model focuses on features that may be common to all stratiform chromite deposits as a way to gain insight into the processes that gave rise to their emplacement and to the significant economic resources contained in them.

  15. Tsunami Deposit Data Base

    NASA Astrophysics Data System (ADS)

    Keating, B. H.; Wanink, M.

    2007-05-01

    A digital database has been established describing tsunami deposits around the world (3 phases; 15 months). The projects involved the review and tabulation of data derived from books, catalogs, journals, preprints, citations and abstracts (currently 1000 references), into a database designed to provide a comprehensive review of the types of tsunami deposits, their geographic distribution and location, sedimentary characteristics, fossil content, age, preservation, run-up, wave height and inundation observations, etc. (34 parameters). The tsunami occurrences can be divided into many subjects, e.g., Volcanogenic (N=375), Seismites (N=49), Co-seismic (N=258), K/T Boundary Impact-triggered debris flows (N=97), Landslides (N=43), etc. Numerous publications compare tsunami deposits to storm deposits (N=38), or analyze the origin of megaboulders (N=22). Tsunami deposits occur throughout geologic time (Pre-Cambrian to present day), and because of plate tectonics, they occur along plate margins (primarily subduction zones) as well as interior to plates. In addition, they occur in epi-continental seas, fjords, etc. Few publications describe depositional processes. Deposits generated by tsunamis occur in multiple environments such as the marine, fresh water, and subaerial. Common characteristics of tsunami deposits include: 1) Deposition of thin sand sheets (can be normal, massive, inversely graded, chaotic or bimodal). 2) Erosional: basal uncomformity, mud balls, rip-up clasts, reworked fossils produced by scouring. 3) Lithology: Stacks of couplets reflecting marine incursions (often sands) into fresh water or subaerial environments (mud, soil, peat). 4) Fossil: Couplets reflects marine fossils, fresh water fossils or a mixed assemblage. 5) Geomorphology: The sand sheets taper landward and can rise in elevation. 6) Deformation: syn-depositional (soft sediments) and intraformational (stiff sediments).

  16. Biological N2-fixation in Boreal Peatlands of Alberta Canada Following Acute N-Deposition: Down-Regulation and Subsequent Post-Recovery Projections.

    NASA Astrophysics Data System (ADS)

    Vile, M. A.; Fillingim, H.

    2015-12-01

    Globally, boreal peatlands cover a mere 3-4 % of the Earth's land surface, yet store ~ 30% of the world's soil carbon and ~9-16% of global soil nitrogen. Biological N2-fixation is the primary input of new nitrogen (N) to bogs in Alberta. We have demonstrated that this process is down regulated in the presence of enhanced atmospheric N deposition such as that from the growing Oil Sands Mining Operations in northern Alberta Canada. An important question for understanding the long term function of bogs in Alberta is whether N2-fixation can recover upon cessation of N pollution, and if so, how quickly? Here we present our preliminary findings in pursuit of this question. We measured rates of biological N2-fixation using the acetylene reduction assay (ARA), with subsequent calibration using 15N2 on separate, but paired incubations. Sphagnum fuscum from bogs at two different sites from northern Alberta were incubated over the course of 3 years, in 3 experimentally added treatments in the field; controls, plots receiving no added N and no water, water only treatments (no added N), and plots that were fertilized with N at a rate of 20 kg·ha-1·yr-1, and plots which had been fertilized with 20 kg·ha-1·yr-1in 2012-2013, but not since. In 2014, the rates of N2-fixation in the 20 kg·ha-1·yr-1plots and the recovering 20 kg·ha-1·yr-1plots were not significantly different, but both were significantly lower than the controls (p<0.05). In 2015, control plots had significantly higher rates of N2-fixation than the plots that had previously received 20 kg·ha-1·yr-1 in 2012 and 2013, and the plots that had not received 20 kg·ha-1·yr-1 since 2013 had significantly higher rates of biological N2-fixation. These data suggest that in a low atmospheric N deposition scenario, and over a short time frame, peatlands of northern Alberta may be able to recover from chronic atmospheric N deposition.

  17. Age models for peat deposits on the basis of coupled lead-210 and radiocarbon data.

    NASA Astrophysics Data System (ADS)

    Piotrowska, Natalia; de Vleeschouwer, François; Sikorski, Jarosław; Sensuła, Barbara; Michczyński, Adam; Fiałkiewicz-Kozieł, Barbara; Palowski, Bernard

    2010-05-01

    The study presents three examples of age-model construction based on the results of 210Pb and 14C dating methods applied to peat deposits. The three sites are ombrotrophic peat bogs: the Misten (Belgium), Slowinskie Bloto (N Poland) and Puscizna Mala (S Poland). All sites have been subjected to multiproxy studies aimed at reconstructing paleoenvironment and human activity, covering the last 1500, 1300 and 1800 years, respectively (De Vleeschouwer et al. 2009A, 2009B, in prep., Fialkiewicz-Koziel, ongoing PhD). A detailed comparison between 210Pb and post-bomb 14C results in the Misten bog has also been carried out by Piotrowska et al. (2009). In all cores, the 210Pb activity was calculated using 210Po and 208Po activities after acid-extraction from bulk samples, subsequent deposition on silver discs and measurements by alpha spectrometry. Unsupported 210Pb was detected until 35cm in Slowinskie Bloto, 15cm in the Misten and 19cm in Puscizna Mala. Constant Rate of Supply (CRS) model was then applied to compute ages of each 1-cm core interval. For the Misten and Slowinskie Bloto, radiocarbon measurements were performed on selected aboveground plant macrofossils, mainly Sphagnum spp. or Calluna vulgaris, Erica tetralix, and Andromeda polyfolia. Radiocarbon ages were determined using accelerator mass spectrometry (AMS) after acid-alkali-acid wash, combustion, purification of carbon dioxide and graphitisation. For Puscizna Mala bulk samples were dated after chemical preparation of benzene for liquid scintillation counting (LSC) or CO2 for gas proportional counting (GPC). Radiocarbon calibration was undertaken using the Intcal04 calibration curve and OxCal 4 software. As a priori information the 210Pb-derived ages were used in a P_Sequence model (Bronk Ramsey, 2008). A number of dates characterized by low agreement with stratigraphical order had to be considered as outliers and rejected from the final age model. For building a continuous age models a non-linear approach

  18. Peat Bog Wildfire Smoke Exposure in Rural North Carolina Is Associated with Cardiopulmonary Emergency Department Visits Assessed through Syndromic Surveillance

    PubMed Central

    Stone, Susan L.; Cascio, Wayne E.; Neas, Lucas M.; Kilaru, Vasu J.; Carraway, Martha Sue; Szykman, James J.; Ising, Amy; Cleve, William E.; Meredith, John T.; Vaughan-Batten, Heather; Deyneka, Lana; Devlin, Robert B.

    2011-01-01

    Background: In June 2008, burning peat deposits produced haze and air pollution far in excess of National Ambient Air Quality Standards, encroaching on rural communities of eastern North Carolina. Although the association of mortality and morbidity with exposure to urban air pollution is well established, the health effects associated with exposure to wildfire emissions are less well understood. Objective: We investigated the effects of exposure on cardiorespiratory outcomes in the population affected by the fire. Methods: We performed a population-based study using emergency department (ED) visits reported through the syndromic surveillance program NC DETECT (North Carolina Disease Event Tracking and Epidemiologic Collection Tool). We used aerosol optical depth measured by a satellite to determine a high-exposure window and distinguish counties most impacted by the dense smoke plume from surrounding referent counties. Poisson log-linear regression with a 5-day distributed lag was used to estimate changes in the cumulative relative risk (RR). Results: In the exposed counties, significant increases in cumulative RR for asthma [1.65 (95% confidence interval, 1.25–2.1)], chronic obstructive pulmonary disease [1.73 (1.06–2.83)], and pneumonia and acute bronchitis [1.59 (1.07–2.34)] were observed. ED visits associated with cardiopulmonary symptoms [1.23 (1.06–1.43)] and heart failure [1.37 (1.01–1.85)] were also significantly increased. Conclusions: Satellite data and syndromic surveillance were combined to assess the health impacts of wildfire smoke in rural counties with sparse air-quality monitoring. This is the first study to demonstrate both respiratory and cardiac effects after brief exposure to peat wildfire smoke. PMID:21705297

  19. Anastomosed river deposits, sedimentation rates, basin subsidence and locations in proximal molasse basins

    SciTech Connect

    Smith, D.G.

    1984-07-01

    Recent research on large sized modern anastomosing river systems (upper Columbia River, British Columbia, Canada, and Magdalena River, Colombia, South America) has recognized six depositional environments: channel, levee, crevasse-splay, lacustrine, marsh, and peat bog or swamp. Average sedimentation rates in both river systems are 5 mm/yr and 3.8 mm/yr, respectively. Such rapid sedimentation rates (vertical accretion) are keeping pace with equivalent rates of basin subsidence. High rates of sedimentation and basin subsidence are most likely to be found at proximal locations in molasse basins during major orogenic pulses. Such conditions were present during the Columbian and Laramide orogenies during the early Cretaceous and Tertiary in the foreland adjacent to the Rocky Mountain system. Thus, channel and crevasse-splay shale-encased sandstone reservoirs and coal, common in anastomosed fluvial rock sequences in proximal molasse settings, should be encountered in parts of the Western Interior sedimentary basin. Such deposits probably have been interpreted as deltaic or alluvial plain and should be reexamined to better predict sandstone trends for hydrocarbon exploration.

  20. A 15 000-year record of climate change in northern New Mexico, USA, inferred from isotopic and elemental contents of bog sediments

    USGS Publications Warehouse

    Cisneros-Dozal, L. M.; Heikoop, J.M.; Fessenden, J.; Anderson, R. Scott; Meyers, P.A.; Allen, C.D.; Hess, M.; Larson, T.; Perkins, G.; Rearick, M.

    2010-01-01

    Elemental (C, N, Pb) and isotopic (??13C, ??15N) measurements of cored sediment from a small bog in northern New Mexico reveal changes in climate during the Late Pleistocene and Holocene. Abrupt increases in Pb concentration and ??13C values ca. 14 420 cal. YBP indicate significant runoff to the shallow lake that existed at that time. Weathering and transport of local volcanic rocks resulted in the delivery of Pb-bearing minerals to the basin, while a 13C-enriched terrestrial vegetation source increased the ??13C values of the sedimentary material. Wet conditions developed over a 300 a period and lasted for a few hundred years. The Younger Dryas period (ca. 12 700-11 500 cal. YBP) caused a reduction in terrestrial productivity reflected in decreasing C/N values, ??15N values consistently greater than 0??? and low organic content. By contrast, aquatic productivity increased during the second half of this period, evidenced by increasing ??13C values at the time of highest abundance of algae. Dry conditions ca. 8 000-6 000 cal. YBP were characterised by low organic carbon content and high Pb concentrations, the latter suggesting enhanced erosion and aeolian transport of volcanic rock. The range in ??13C, ??15N and C/N values in the sedimentary record fall within the range of modern plants, except during the periods of runoff and drought. The sedimentary record provides evidence of natural climate variability in northern New Mexico, including short- (multi-centennial) and long-(millennial) term episodes during the Late Pleistocene and Holocene. Copyright ?? 2010 John Wiley & Sons, Ltd.

  1. Testing a new version of the DigiBog model to explore the differential response of peatland microforms to shifts in surface wetness

    NASA Astrophysics Data System (ADS)

    Garneau, Michelle; Baird, Andrew J.; Morris, Paul J.; van Bellen, Simon

    2016-04-01

    Over the last decades, many hypotheses have been put forward to explain pool formation in northern peatlands including topographic, biotic or climatic factors. Several studies suggest that pool formation is primarily controlled by autogenic, edaphic and topographic factors rather than external climatic influences (allogenic factors). However, there is still no consensus to explain pool formation and to confirm whether their initiation is primarily associated with autogenic or allogenic processes. Subarctic fens in northeastern Canada are characterized by a patterned surface of pools, flarks and narrow strings. Due to their geographic location at the northern ombrotrophic peatland distribution, these poor fens have been highly sensitive to hydroclimatic variations that influenced pool development and expansion. Our data indicate that wet hollows or shallow pools developed at minimal ages between ca 4200 cal BP and ca 2500 cal BP. We hypothesize that pool developed as secondary features under wetter and cooler conditions that (i) caused shorter growing seasons which negatively impacted on peat accumulation and (ii) led to lower rates of evaporation, and that (i) and (ii) in combination led to increased surface wetness. The differential response of microforms to shifts in surface wetness show the complexity of processes involved in pool initiation. A recent version of the DigiBog model (Morris et al, 2015), that allows for sub-seasonal variations in precipitation and evaporation, is used to explore the interactions between climate, growing season, peat productivity, peat hydraulic properties and water-table behaviour. Model results suggest that decreases in growing season length, combined with decreases in evapotranspiration, can explain long-lived shifts to wetter conditions in peatlands. If evapotranspiration is reduced but growing season does not vary, long-lived shifts in peatland wetness are less likely and the peatland instead tends to show a homeostatic

  2. The effects of ecological restoration, on soil-pore water quality and DOC concentrations, on a British upland blanket bog.

    NASA Astrophysics Data System (ADS)

    Qassim, Suzane; Dixon, Simon; Rowson, James; Worrall, Fred; Evans, Martin

    2013-04-01

    Polluted by past atmospheric deposition, eroded and burnt, the Bleaklow plateau (Peak district National Park, UK) has long been degraded. Peatlands are important carbon reservoirs and can act as sources or sinks of carbon. Dissolved organic carbon (DOC) is carbon lost from peatlands via the fluvial pathway and as the major component of water colour it is costly to remove during water treatment processes. The Bleaklow Summit peatlands, were subjected to a large wildfire in 2003 devegetating 5.5km2. This fire prompted stakeholders to initiate a large-scale programme of restoration of the plateau. This study considered restoration techniques across four sites: all four sites were seeded with lawn grass, limed and fertilised; to raise the pH and allow establishment of vegetation. In addition to these interventions, one site also had a mulch of Calluna vulgaris applied to the surface to allow soil stabilisation and promote vegetation establishment and another site had biodegradable geojute textile mesh installed, to stabilize the steep gully surfaces. Another site had a gully block installed, to reduce peat desiccation and erosion. This study will compare the four restored sites to two types of comparators: bare soil sites where no restoration was undertaken and a naturally vegetated site unaffected by the 2003 wildfire. Each site had six replicate dipwells, installed in two groups of three. The depth to the water table was monitored and soil water samples collected for analysis, monthly for 5 years, from Nov 2006 - Jan 2012. No significant difference in DOC concentration was found between control and treated sites. There was, however, a significant difference in DOC composition between sites and over the 5 year period of monitoring. UV-vis absorbance of the samples is used to quantify the fulvic to humic components of DOC. The vegetated control was not significantly different to the bare sites; however the vegetated control had a significantly greater humic fraction of

  3. Ammonia emission and deposition in Scotland and its potential environmental impacts.

    PubMed

    Sutton, M A; Dragosits, U; Hellsten, S; Place, C J; Dore, A J; Tang, Y S; van Dijk, N; Love, L; Fournier, N; Vieno, M; Weston, K J; Smith, R I; Coyle, M; Roy, D; Hall, J; Fowler, D

    2004-09-02

    The main source of atmospheric ammonia (NH3) in Scotland is livestock agriculture, which accounts for 85% of emissions. The local magnitude of emissions therefore depends on livestock density, type, and management, with major differences occurring in various parts of Scotland. Local differences in agricultural activities therefore result in a wide range of NH3 emissions, ranging from less than 0.2 kg N ha(-1) year(-1) in remote areas of the Scottish Highlands to over 100 kg N ha(-1) year-1 in areas with intensive poultry farming. Scotland can be divided loosely into upland and lowland areas, with NH3 emission being less than and more than 5 kg N ha(-1) year(-1), respectively. Many semi-natural ecosystems in Scotland are vulnerable to nitrogen deposition, including bogs, moorlands, and the woodland ground flora. Because NH3 emissions occur in the rural environment, the local deposition to sensitive ecosystems may be large, making it essential to assess the spatial distribution of NH3 emissions and deposition. A spatial model is applied here to map NH3 emissions and these estimates are applied in atmospheric dispersion and deposition models to estimate atmospheric concentrations of NH3 and NH4+, dry deposition of NH3, and wet deposition of NHx. Although there is a high level of local variability, modelled NH3 concentrations show good agreement with the National Ammonia Monitoring Network, while wet deposition is largest at high altitude sites in the south and west of Scotland. Comparison of the modelled NHx deposition fields with estimated thresholds for environmental effects ("critical loads") shows that thresholds are exceeded across most of lowland Scotland and the Southern Uplands. Only in the cleanest parts of the north and west is nitrogen deposition not a cause for concern. Given that the most intense effects occur within a few kilometres of sources, it is suggested that local spatial abatement policies would be a useful complement to traditional policies that

  4. World oil shale deposits

    SciTech Connect

    Hook, C.O.; Russell, P.L.

    1982-01-01

    The article estimates resources in-place and their oil equivalent. The major deposits are described in the U.S., Australia, USSR, Peoples Republic of China, Morocco, Israel, Jordan, Syria, Europe and South America. 2 refs.

  5. Chemical vapor deposition growth

    NASA Technical Reports Server (NTRS)

    Ruth, R. P.; Manasevit, H. M.; Kenty, J. L.; Moudy, L. A.; Simpson, W. I.; Yang, J. J.

    1976-01-01

    A chemical vapor deposition (CVD) reactor system with a vertical deposition chamber was used for the growth of Si films on glass, glass-ceramic, and polycrystalline ceramic substrates. Silicon vapor was produced by pyrolysis of SiH4 in a H2 or He carrier gas. Preliminary deposition experiments with two of the available glasses were not encouraging. Moderately encouraging results, however, were obtained with fired polycrystalline alumina substrates, which were used for Si deposition at temperatures above 1,000 C. The surfaces of both the substrates and the films were characterized by X-ray diffraction, reflection electron diffraction, scanning electron microscopy optical microscopy, and surface profilometric techniques. Several experiments were conducted to establish baseline performance data for the reactor system, including temperature distributions on the sample pedestal, effects of carrier gas flow rate on temperature and film thickness, and Si film growth rate as a function of temperature.

  6. Automatic Payroll Deposit System.

    ERIC Educational Resources Information Center

    Davidson, D. B.

    1979-01-01

    The Automatic Payroll Deposit System in Yakima, Washington's Public School District No. 7, directly transmits each employee's salary amount for each pay period to a bank or other financial institution. (Author/MLF)

  7. Gemstone deposits of Serbia

    NASA Astrophysics Data System (ADS)

    Miladinović, Zoran; Simić, Vladimir; Jelenković, Rade; Ilić, Miloje

    2016-06-01

    Gemstone minerals in Serbia have never been regarded as an interesting and significant resource. Nevertheless, more than 150 deposits and occurrences have been recorded and some of them preliminarily explored in the last 50 years. The majority of deposits and occurrences are located within the Serbo-Macedonian metallogenic province and the most significant metallogenic units at the existing level of knowledge are the Fruska Gora ore district, Cer ore district, Sumadija metallogenic zone, Kopaonik metallogenic zone and Lece-Halkidiki metallogenic zone. The most important genetic type of deposits is hydrothermal, particularly in case of serpentinite/peridotite as host/parent rock. Placer deposits are also economically important. The dominant gemstones are silica minerals: chalcedony (Chrysoprase, carnelian, bluish chalcedony etc.), jasper (picture, landscape, red etc.), common opal (dendritic, green, milky white etc.), silica masses (undivided), and quartz (rock crystal, amethyst etc.). Beside silica minerals significant gemstones in Serbia include also beryl (aquamarine), garnet (almandine and pyrope), tourmaline, fluorite, rhodochrosite, carbonate-silica breccia, carbonate-silica onyx, silicified wood, howlite, serpentinite, marble onyx, and kyanite. This paper aims to present an overview of Serbian gemstone deposits and occurrences and their position based on a simplified gemstone metallogenic map of Serbia, as well as genetic-industrial classification of gemstone deposits and gemstone varieties.

  8. Convective microsphere monolayer deposition

    NASA Astrophysics Data System (ADS)

    Gilchrist, James

    2011-03-01

    There is perhaps no simpler way of modifying surface chemistry and morphology than surface deposition of particles. Micron-sized microspheres were deposited into thin films via rapid convective deposition, similar to the `coffee ring effect' using a similar method to that studied by Prevo and Velev, Langmuir, 2003. By varying deposition rate and blade angle, the optimal operating ranges in which 2D close-packed arrays of microspheres existed were obtained. Self-assembly of colloidal particles through a balance of electrostatic and capillary forces during solvent evaporation was revealed. These interactions were explored through a model comparing the residence time of a particle in the thin film and the characteristic time of capillary-driven crystallization to describe the morphology and microstructure of deposited particles. Co-deposition of binary suspensions of micron and nanoscale particles was tailored to generate higher-quality surface coatings and a simple theory describes the immergence of instabilities that result in formation of stripes. Optical and biomedical applications that utilize the described nanoscale control over surface morphology will also be discussed.

  9. Deposition times in the northeastern United States during the Holocene: establishing valid priors for Bayesian age models

    NASA Astrophysics Data System (ADS)

    Goring, S.; Williams, J. W.; Blois, J. L.; Jackson, S. T.; Paciorek, C. J.; Booth, R. K.; Marlon, J. R.; Blaauw, M.; Christen, J. A.

    2012-08-01

    Age-depth relationships in sedimentary archives such as lakes, wetlands and bogs are non-linear with irregular probability distributions associated with calibrated radiocarbon dates. Bayesian approaches are thus well-suited to understanding relationships between age and depth for use in paleoecological studies. Bayesian models for the accumulation of sediment and organic matter within basins combine dated material from one or more records with prior information about the behavior of deposition times (yr/cm) based on expert knowledge. Well-informed priors are essential to good modeling of the age-depth relationship, but are particularly important in cases where data may be sparse (e.g., few radiocarbon dates), or unclear (e.g., age-reversals, coincident dates, age offsets, outliers and dates within a radiocarbon plateau). Here we assessed Holocene deposition times using 204 age-depth models obtained from the Neotoma Paleoecology Database (www.neotomadb.org) for both lacustrine and palustrine environments across the northeastern United States. These age-depth models were augmented using biostratigraphic events identifiable within pollen records from the northeastern United States during the Holocene and late-Pleistocene. Deposition times are significantly related to depositional environment (palustrine and lacustrine), sediment age, and sediment depth. Spatial variables had non-significant relationships with deposition time when site effects were considered. The best-fit model was a generalized additive mixed model that relates deposition time to age, stratified by depositional environment with site as a random factor. The best-fit model accounts for 63.3% of the total deviance in deposition times. The strongly increasing accumulation rates of the last 500-1000 years indicate that gamma distributions describing lacustrine deposition times (α = 1.08, β = 18.28) and palustrine deposition times (α = 1.23, β = 22.32) for the entire Holocene may be insufficient for

  10. Becquerel Crater Deposit

    NASA Technical Reports Server (NTRS)

    2002-01-01

    (Released 28 May 2002) The finely layered deposit in Becquerel crater, seen in the center of this THEMIS image, is slowly being eroded away by the action of windblown sand. Dark sand from a source north of the bright deposit is collecting along its northern edge, forming impressive barchan style dunes. These vaguely boomerang-shaped dunes form with their two points extending in the downwind direction, demonstrating that the winds capable of moving sand grains come from the north. Grains that leave the dunes climb the eroding stair-stepped layers, collecting along the cliff faces before reaching the crest of the deposit. Once there, the sand grains are unimpeded and continue down the south side of the deposit without any significant accumulation until they fall off the steep cliffs of the southern margin. The boat-hull shaped mounds and ridges of bright material called yardangs form in response to the scouring action of the migrating sand. To the west, the deposit has thinned enough that the barchan dunes extend well into the deeply eroded north-south trending canyons. Sand that reaches the south side collects and reforms barchan dunes with the same orientation as those on the north side of the deposit. Note the abrupt transition between the bright material and the dark crater floor on the southern margin. Steep cliffs are present with no indication of rubble from the obvious erosion that produced them. The lack of debris at the base of the cliffs is evidence that the bright material is readily broken up into particles that can be transported away by the wind. The geological processes that are destroying the Becquerel crater deposit appear active today. But it is also possible that they are dormant, awaiting a particular set of climatic conditions that produces the right winds and perhaps even temperatures to allow the erosion to continue.

  11. 76 FR 41392 - Interest on Deposits; Deposit Insurance Coverage

    Federal Register 2010, 2011, 2012, 2013, 2014

    2011-07-14

    ... From the Federal Register Online via the Government Publishing Office FEDERAL DEPOSIT INSURANCE CORPORATION 12 CFR Parts 329 and 330 RIN 3064-AD78 Interest on Deposits; Deposit Insurance Coverage AGENCY: Federal Deposit Insurance Corporation (FDIC). ACTION: Final rule. SUMMARY: The FDIC is issuing a...

  12. 76 FR 21265 - Interest on Deposits; Deposit Insurance Coverage

    Federal Register 2010, 2011, 2012, 2013, 2014

    2011-04-15

    ... From the Federal Register Online via the Government Publishing Office FEDERAL DEPOSIT INSURANCE CORPORATION 12 CFR Parts 329 and 330 RIN 3064-AD78 Interest on Deposits; Deposit Insurance Coverage AGENCY: Federal Deposit Insurance Corporation (FDIC). ACTION: Notice of proposed rulemaking (NPR) and request...

  13. Vacuum arc deposition devices

    NASA Astrophysics Data System (ADS)

    Boxman, R. L.; Zhitomirsky, V. N.

    2006-02-01

    The vacuum arc is a high-current, low-voltage electrical discharge which produces a plasma consisting of vaporized and ionized electrode material. In the most common cathodic arc deposition systems, the arc concentrates at minute cathode spots on the cathode surface and the plasma is emitted as a hypersonic jet, with some degree of contamination by molten droplets [known as macroparticles (MPs)] of the cathode material. In vacuum arc deposition systems, the location and motion of the cathode spots are confined to desired surfaces by an applied magnetic field and shields around undesired surfaces. Substrates are mounted on a holder so that they intercept some portion of the plasma jet. The substrate often provides for negative bias to control the energy of depositing ions and heating or cooling to control the substrate temperature. In some systems, a magnetic field is used to guide the plasma around an obstacle which blocks the MPs. These elements are integrated with a deposition chamber, cooling, vacuum gauges and pumps, and power supplies to produce a vacuum arc deposition system.

  14. Vacuum arc deposition devices

    SciTech Connect

    Boxman, R.L.; Zhitomirsky, V.N.

    2006-02-15

    The vacuum arc is a high-current, low-voltage electrical discharge which produces a plasma consisting of vaporized and ionized electrode material. In the most common cathodic arc deposition systems, the arc concentrates at minute cathode spots on the cathode surface and the plasma is emitted as a hypersonic jet, with some degree of contamination by molten droplets [known as macroparticles (MPs)] of the cathode material. In vacuum arc deposition systems, the location and motion of the cathode spots are confined to desired surfaces by an applied magnetic field and shields around undesired surfaces. Substrates are mounted on a holder so that they intercept some portion of the plasma jet. The substrate often provides for negative bias to control the energy of depositing ions and heating or cooling to control the substrate temperature. In some systems, a magnetic field is used to guide the plasma around an obstacle which blocks the MPs. These elements are integrated with a deposition chamber, cooling, vacuum gauges and pumps, and power supplies to produce a vacuum arc deposition system.

  15. Metallogeny of gold deposits

    SciTech Connect

    Hutchinson, R.W.

    1985-01-01

    The metallogeny of various gold deposits, particularly their broad temporal and spatial relations, and their relations to other metallic ores, is significant to genetic understanding and also useful in exploration. Archean gold deposits co-exist, both regionally and locally, with certain iron formations, massive base metal and nickel sulfide ores, but these occur generally in differing parts of the host stratigraphic sequences. Gold deposits in marine-eugeosynclinal environments are most important and numerous in Archean rocks. They become increasingly rare in successively younger strata where epithermal deposits in subaerial-continental rocks become important. The hydrothermal systems that formed both were apparently similar; one active in submarine tectonic settings, the other in sub-volcanic continental ones. Gold was apparently first introduced extensively into supracrustal rocks by sub-sea floor hydrothermal processes in Archean time, forming gold-enriched exhalites. These were reworked by metamorphic processes forming epithermal veins in many lode districts, and by sedimentary processes in the Witwatersrand. Epithermal gold deposits were generated where these older, auriferous basement source rocks were affected by younger, plutonic-volcanic-hydrothermal activity.

  16. Pulsed laser deposition: Prospects for commercial deposition of epitaxial films

    SciTech Connect

    Muenchausen, R.E.

    1999-03-01

    Pulsed laser deposition (PLD) is a physical vapor deposition (PVD) technique for the deposition of thin films. The vapor source is induced by the flash evaporation that occurs when a laser pulse of sufficient intensity (about 100 MW/cm{sup 2}) is absorbed by a target. In this paper the author briefly defines pulsed laser deposition, current applications, research directed at gaining a better understanding of the pulsed laser deposition process, and suggests some future directions to enable commercial applications.

  17. Venus - Landslide Deposits

    NASA Technical Reports Server (NTRS)

    1992-01-01

    The Magellan spacecraft has observed remnant landslide deposits apparently resulting from the collapse of volcanic structures. This image, centered at 45.2 degrees south latitude, 201.4 degrees east longitude, shows a collapse deposit 70 kilometers (43 miles) across. The bright, highly textured deposit near the center of the image probably consists of huge blocks of fractured volcanic rock, many as large as several hundred meters across. A remnant of the volcano itself, about 20 kilometers (12.4 miles) across, is seen at the center of the image. The distorted radar appearance of the volcano is a result of extremely steep slopes on the 'scars' from which the landslide material originated. A field of numerous small volcanic domes can be seen in the northern half of the image. The bright irregular lineaments trending to the north-northwest are ridges caused by regional tectonic deformation of the upper layers of the Venusian crust.

  18. Revealing spatial distribution of soil organic carbon contents and stocks of a disturbed bog relict by in-situ NIR and apparent EC mapping

    NASA Astrophysics Data System (ADS)

    Bechtold, Michel; Tiemeyer, Bärbel; Don, Axel; Altdorff, Daniel; van der Kruk, Jan; Huisman, Johan A.

    2013-04-01

    Previous studies showed that in-situ visible near-infrared (vis-NIR) spectroscopy can overcome the limitations of conventional soil sampling. Costs can be reduced and spatial resolution enhanced when mapping field-scale variability of soil organic carbon (SOC). Detailed maps can help to improve SOC management and lead to better estimates of field-scale total carbon stocks. Knowledge of SOC field patterns may also help to reveal processes and factors controlling SOC variability. In this study, we apply in situ vis-NIR and apparent electrical conductivity (ECa) mapping to a disturbed bog relict. The major question of this application study was how field-scale in-situ vis-NIR mapping performs for a very heterogeneous area and under difficult grassland conditions and under highly-variable water content conditions. Past intensive peat cutting and deep ploughing in some areas, in combination with a high background heterogeneity of the underlying mineral sediments, have led to a high variability of SOC content (5.6 to 41.3 %), peat layer thickness (25 to 60 cm) and peat degradation states (from nearly fresh to amorphous). Using a field system developed by Veris Technologies (Salina KS, USA), we continuously collected vis-NIR spectra at 10 cm depth (measurement range: 350 nm to 2200 nm) over an area of around 12 ha with a line spacing of about 12 m. The system includes a set of discs for measuring ECa of the first 30 and 90 cm of the soil. The same area was also mapped with a non-invasive electro-magnetic induction (EMI) setup that provided ECa data of the first 25, 50 and 100 cm. For calibration and validation of the spatial data, we took 30 representative soil samples and 15 soil cores of about 90 cm depth, for which peat thickness, water content, pore water EC, bulk density (BD), as well as C and N content were determined for various depths. Preliminary results of the calibration of the NIR spectra to the near-surface SOC contents indicate good data quality despite the

  19. High soil solution carbon und nitrogen concentrations in a drained Atlantic bog are reduced to natural levels by 10 yr of rewetting

    NASA Astrophysics Data System (ADS)

    Frank, S.; Tiemeyer, B.; Gelbrecht, J.; Freibauer, A.

    2013-10-01

    Artificial drainage of peatlands causes dramatic changes in the release of greenhouse gases and in the export of dissolved carbon (C) and nutrients to downstream ecosystems. Rewetting anthropogenically altered peatlands offers a possibility to reduce nitrogen (N) and C losses. In this study, we investigate the impact of drainage and rewetting on the cycling of dissolved C and N as well as on dissolved gases over a period of 1 yr and 4 month, respectively. The peeper technique was used to receive a high vertical sampling resolution. Within one Atlantic bog complex a near natural site, two drained grasslands sites with different mean water table positions, and a former peat cutting area rewetted 10 yr ago were chosen. Our results clearly indicate that drainage increased the concentration of dissolved organic carbon (DOC), ammonia, nitrate and dissolved organic nitrogen (DON) compared to the near natural site. Drainage depth further determined the release and therefore the concentration level of DOC and N species, but the biochemical cycling and therefore dissolved organic matter (DOM) quality and N species composition were unaffected. Thus, especially deep drainage can cause high DOC losses. In general, DOM at drained sites was enriched in aromatic moieties as indicated by SUVA280 and showed a higher degradation status (lower DOC to DON ratio) compared to the near natural site. At the drained sites, equal C to N ratios of uppermost peat layer and DOC to DON ratio of DOM in soil solution suggest that the uppermost degraded peat layer is the main source of DOM. Nearly constant DOC to DON ratios and SUVA280 values with depth furthermore indicated that DOM moving downwards through the drained sites remained largely unchanged. DON and ammonia contributed most to the total dissolved nitrogen (TN). The subsoil concentrations of nitrate were negligible due to strong decline in nitrate around mean water table depth. Methane production during the winter months at the drained

  20. Mucilaginibacter paludis gen. nov., sp. nov. and Mucilaginibacter gracilis sp. nov., pectin-, xylan- and laminarin-degrading members of the family Sphingobacteriaceae from acidic Sphagnum peat bog.

    PubMed

    Pankratov, Timofei A; Tindall, Brian J; Liesack, Werner; Dedysh, Svetlana N

    2007-10-01

    Two facultatively aerobic, heterotrophic bacteria capable of degrading pectin, xylan, laminarin and some other polysaccharides were obtained from the acidic Sphagnum peat bog Bakchar, in western Siberia, Russia, and were designated strains TPT18(T) and TPT56(T). Cells of these isolates are Gram-negative, non-motile, long rods that are covered by large capsules. On ageing, they transform into spherical L-forms. Strains TPT18(T) and TPT56(T) are acido- and psychrotolerant organisms capable of growth at pH 4.2-8.2 (with an optimum at pH 6.0-6.5) and at 2-33 degrees C (with an optimum at 20 degrees C). The major fatty acids are iso-C(15 : 0), anteiso-C(15 : 0), iso-C(17 : 0) 3-OH and summed feature 3 (iso-C(15 : 0) 2-OH and/or C(16 : 1)omega7c); the quinones are MK-7 and MK-6. Comparative 16S rRNA gene sequence analysis revealed that the novel strains share 97 % sequence similarity and belong to the family Sphingobacteriaceae; however, they are related only distantly to members of the genera Pedobacter (91.8-93.3 % similarity) and Sphingobacterium (89.6-91.2 % similarity). The DNA G+C content of strains TPT18(T) and TPT56(T) is 42.4 and 46.1 mol%, respectively. The low DNA-DNA hybridization value (42 %) and a number of phenotypic differences between strains TPT18(T) and TPT56(T) indicated that they represent two separate species. Since the two isolates are clearly distinct from all currently described members of the family Sphingobacteriaceae, we propose a novel genus, Mucilaginibacter gen. nov., containing two novel species, Mucilaginibacter gracilis sp. nov. and Mucilaginibacter paludis sp. nov. The type strains of Mucilaginibacter gracilis and Mucilaginibacter paludis are respectively TPT18(T) (=ATCC BAA-1391(T) =VKM B-2447(T)) and TPT56(T) (=ATCC BAA-1394(T) =VKM B-2446(T)).

  1. Small scale soil carbon and moisture gradients in a drained peat bog grassland and their influence on CO2, CH4 and N2O fluxes

    NASA Astrophysics Data System (ADS)

    Leiber-Sauheitl, K.; Fuß, R.; Freibauer, A.

    2012-04-01

    Due to the UNFCCC report requirements of each country on the emissions of greenhouse gases from key sources the joint research project "Organic Soils" was established in Germany. The project's objective is to improve the data set on greenhousegas emissions from organic soils in Germany. Within 12 German Project Catchments emissions from different types of organic soils, e.g. under different land uses and hydrological conditions, are measured. At the location "Großes Moor" near Gifhorn (Lower Saxony) the effects of small-scale soil organic carbon and groundwater level gradients on the GHG fluxes (CO2, CH4 and N2O) are quantified. The study area is located within a former peat bog altered by drainage and peat cutting, which is currently grassland under extensive agricultural use. The focus of the study is on the acquisition of CO2, CH4 and N2O fluxes on six sites via manual closed chambers. In order to calculate the annual CO2 exchange rate, va