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Sample records for upland peat soils

  1. Peat soils as a source of lead contamination to upland fluvial systems.

    PubMed

    Rothwell, James J; Evans, Martin G; Daniels, Stephen M; Allott, Timothy E H

    2008-06-01

    Upland peat soils are generally regarded as effective sinks of atmospherically deposited lead. However, the physical process of erosion has the potential to transform peat soils from sinks to sources of lead contamination. Lead input and fluvial lead outputs (dissolved+particulate) were estimated for a contaminated and severely eroding peatland catchment in the southern Pennines, UK. Lead input to the catchment is 30.0+/-6.0gha(-1)a(-1) and the output from the catchment is 317+/-22.4gha(-1)a(-1). Suspended particulate matter accounts for 85% of lead export. Contaminated peat soils of the catchment are a significant source of lead to the fluvial system. This study has demonstrated strong coupling between the physical process of erosion and the mobilization of lead into the fluvial system. The process of peat erosion should therefore be considered when estimating lead outputs from peatland catchments, especially in the context of climate change. PMID:17949867

  2. Land management as a factor controlling dissolved organic carbon release from upland peat soils 1: spatial variation in DOC productivity.

    PubMed

    Yallop, A R; Clutterbuck, B

    2009-06-01

    The importance of soil storage in global carbon cycling is well recognised and factors leading to increased losses from this pool may act as a positive feedback mechanism in global warming. Upland peat soils are usually assumed to serve as carbon sinks, there is however increasing evidence of carbon loss from upland peat soils, and DOC concentrations in UK rivers have increased markedly over the past three decades. A number of drivers for increasing DOC release from peat soils have been proposed although many of these would not explain fine-scale variations in DOC release observed in many catchments. We examined the effect of land use and management on DOC production in upland peat catchments at two spatial scales within the UK. DOC concentration was measured in streams draining 50 small-scale catchments (b3 km2) in three discrete regions of the south Pennines and one area in the North Yorkshire Moors. Annual mean DOC concentration was also derived from water colour data recorded at water treatment works for seven larger scale catchments (1.5-20 km2) in the south Pennines. Soil type and land use/management in all catchments were characterised from NSRI digital soil data and ortho-corrected colour aerial imagery. Of the factors assessed, representing all combinations of soil type and land use together with catchment slope and area, the proportion of exposed peat surface resulting from new heather burning was consistently identified as the most significant predictor of variation in DOC concentration. This relationship held across all blanket peat catchments and scales. We propose that management activities are driving changes in edaphic conditions in upland peat to those more favourable for aerobic microbial activity and thus enhance peat decomposition leading to increased losses of carbon from these environments. PMID:19345986

  3. The effects of burning and sheep-grazing on water table depth and soil water quality in a upland peat

    NASA Astrophysics Data System (ADS)

    Worrall, F.; Armstrong, A.; Adamson, J. K.

    2007-06-01

    SummaryRotational burning of heather to improve grazing and grouse breeding is a common management practice for upland catchments in the UK. However, the effects of such practices on hydrology and water quality are not well understood because the timescale of burning rotation is typically between 7 and 20 years thus requiring long-term experiments in order to resolve the effects. Furthermore, land management, such as changes in burning or grazing practices, has been proposed as a possible strategy for the remediation of the widespread increases in dissolved organic carbon (DOC) observed across the northern hemisphere. This study is based on a long-term experiment on the effect of different rotational burning cycles and grazing intensities on upland vegetation and aims to understand the effects of these management strategies on hydrology and water quality. The main outcomes are: The depth to water table in the soil showed significant differences between different burning rotations and grazing intensities. Depth to water table was greatest on plots where burning did not occur or for longer burning cycles where livestock had been excluded. The pH and conductivity of sampled soil water showed no significant difference between grazing treatments, with the presence of burning being the most important factor (frequency of the burning cycle was not important). The DOC content showed no significant difference between grazing treatments but showed a significant decrease with the presence of burning, though no direct relationship with the depth to water table could be found. Burn management explains only a small proportion of the variance in the composition of the DOC, rather the variation is dominated by the differences between days of sampling and seasonal variation. Therefore, this study suggests that land management controls hydrology and water quality through controlling the development of vegetation.

  4. Decomposition of peat from upland boreal forest: Temperature dependence and sources of respired carbon

    NASA Astrophysics Data System (ADS)

    Dioumaeva, Irina; Trumbore, Susan; Schuur, Edward A. G.; Goulden, Michael L.; Litvak, Marcy; Hirsch, Adam I.

    2002-02-01

    The response of large stores of carbon in boreal forest soils to global warming is a major uncertainty in predicting the future carbon budget. We measured the temperature dependence of decomposition for upland boreal peat under black spruce forest with sphagnum and feather moss understory using incubation experiments. CO2 efflux rates clearly responded to temperature, which ranged from -10 to +8C by 2C increments. At temperatures below 0C, significant decomposition was observed in feather moss peat but not in wetter sphagnum peat. Above 0C, decomposition was exponentially related to temperature, corresponding to a Q(10) (the ratio of the rate of CO2 evolution at one temperature divided by that at a temperature 10C cooler) of 4.4 for feather moss and 3.1 for sphagnum peat. The greatest change in CO2 evolution rate with temperature occurred between -2 and 0C, which coincided with the phase transition of soil water. We saw no large change in the rate of CO2 evolution between incubation experiments separated by a 6 month storage period for feather moss peat. Stable C isotope measurements of evolved CO2 and the rate of change of CO2 evolution with time suggest different substrates are used to sustain heterotrophic respiration above and below freezing. Radiocarbon signatures of CO2 respired from both types of peat reflected significant contributions from C fixed in the last 35 years ("bomb" 14C) as well as C fixed prior to 1950. We observed no change in the ?14C of respired CO2 with temperature. Isotopic signatures of peat components showed that a combination of substrates must contribute to the CO2 evolved in our incubations. Decomposition of fine roots (which made up less than 7% of the total peat C) accounted for 50% of respired CO2 in feather moss peat and for 30% of respired CO2 in sphagnum peat. Fine-grained (<1 mm), more humified material that makes up 60-70% of the bulk peat organic carbon contributed significantly to heterotrophic respiration (30% in feather moss and 50% in sphagnum moss peat), despite slow decomposition rates. Increased temperatures caused enhanced decomposition from all pools without changing their relative contributions. Because the contribution of peat decomposition is a small portion of total soil respiration at the study site, increased respiration rates would be difficult to measure as increased fluxes in the field. Nonetheless, sustained warming could lead to significant loss of C from these peat layers.

  5. Decomposition of peat from upland boreal forest: Temperature dependence and sources of respired carbon

    NASA Astrophysics Data System (ADS)

    Dioumaeva, Irina; Trumbore, Susan; Schuur, Edward A. G.; Goulden, Michael L.; Litvak, Marcy; Hirsch, Adam I.

    2003-02-01

    The response of large stores of carbon in boreal forest soils to global warming is a major uncertainty in predicting the future carbon budget. We measured the temperature dependence of decomposition for upland boreal peat under black spruce forest with sphagnum and feather moss understory using incubation experiments. CO2 efflux rates clearly responded to temperature, which ranged from -10 to +8C by ~2C increments. At temperatures below 0C, significant decomposition was observed in feather moss peat but not in wetter sphagnum peat. Above 0C, decomposition was exponentially related to temperature, corresponding to a Q(10) (the ratio of the rate of CO2 evolution at one temperature divided by that at a temperature 10C cooler) of 4.4 for feather moss and 3.1 for sphagnum peat. The greatest change in CO2 evolution rate with temperature occurred between -2 and 0C, which coincided with the phase transition of soil water. We saw no large change in the rate of CO2 evolution between incubation experiments separated by a 6 month storage period for feather moss peat. Stable C isotope measurements of evolved CO2 and the rate of change of CO2 evolution with time suggest different substrates are used to sustain heterotrophic respiration above and below freezing. Radiocarbon signatures of CO2 respired from both types of peat reflected significant contributions from C fixed in the last 35 years (``bomb'' 14C) as well as C fixed prior to 1950. We observed no change in the ?14C of respired CO2 with temperature. Isotopic signatures of peat components showed that a combination of substrates must contribute to the CO2 evolved in our incubations. Decomposition of fine roots (which made up less than 7% of the total peat C) accounted for ~50% of respired CO2 in feather moss peat and for ~30% of respired CO2 in sphagnum peat. Fine-grained (<1 mm), more humified material that makes up 60-70% of the bulk peat organic carbon contributed significantly to heterotrophic respiration (~30% in feather moss and ~50% in sphagnum moss peat), despite slow decomposition rates. Increased temperatures caused enhanced decomposition from all pools without changing their relative contributions. Because the contribution of peat decomposition is a small portion of total soil respiration at the study site, increased respiration rates would be difficult to measure as increased fluxes in the field. Nonetheless, sustained warming could lead to significant loss of C from these peat layers.

  6. Extreme peat burning along peatland-upland interfaces of the Western Boreal Plain

    NASA Astrophysics Data System (ADS)

    Lukenbach, M.; Hokanson, K.; Devito, K. J.; Kettridge, N.; Thompson, D.; Petrone, R. M.; Waddington, J. M.

    2013-12-01

    Wildfire is the largest disturbance affecting peatlands in the Western Boreal Forest, releasing 4700 Gg C a-1 over ~1500 km2 annually. Under future climate scenarios the amount of area burned in this region is forecast to increase by 25-100%, potentially converting these ecosystems into a regional net source of carbon to the atmosphere. During wildfire, the majority of carbon released from peatlands is attributable to peat smouldering with burn depths generally ranging from 5 - 20 cm of peat. However, no study has documented the incidence of an extreme smouldering event and the conditions necessary for such an event to occur. Here we report on a smouldering event during the Utikuma Complex forest fire (SWF-060, ~90,000 ha) in May, 2011 at the Utikuma Lake Research Study Area (URSA) in Alberta's Western Boreal Plain, where peat burn depths exceeded one meter along a peatland-upland interface (range = 0.12 to 1.10 m, mean = 0.54 m). We applied the Peat Smouldering and Ignition model (PSI) at an adjacent unburned peatland-upland interface to characterize the hydrological and hydrophysical conditions necessary for these extreme burn depths. Model outputs indicate that the coupling of dense peat (bulk density > 150 kg m-3) and low peat moisture (GWC < 250%) allow for severe smouldering to propagate deep into the peat profile. We argue that peatland-upland interfaces, which likely release ten times more carbon per meter squared than peatland centers, are hotspots for peat smouldering due to dynamic hydrological conditions that reduce the moisture content of high-density peat during dry periods. We suggest the hydrogeological setting of peatlands is essential for identifying peatland-upland interfaces as areas highly vulnerable to smouldering and for assisting fire managers and scientists in predicting and mitigating the effects of extreme peat burning events. Burned peatland-upland interface

  7. Peat

    USGS Publications Warehouse

    Apodaca, Lori E.

    2013-01-01

    The article looks at the U.S. peat market as of July 2013. Peat is produced from deposits of plant organic materials in wetlands and includes varieties such as reed-sedge, sphagnum moss, and humus. Use for peat include horticultural soil additives, filtration, and adsorbents. Other topics include effects of environmental protection regulations on peat extraction, competition from products such as coir, composted organic waste, and wood products, and peatland carbon sinks.

  8. Impacts of peat restoration on peak flow characteristics of upland headwater catchments

    NASA Astrophysics Data System (ADS)

    Allott, Tim; Evans, Martin; Agnew, Clive; Milledge, Dave; Pilkington, Mike; Maskill, Rachael

    2014-05-01

    As part of the current focus on ecosystem services provided by peatlands, there is renewed interest in the hydrology of upland blanket peats and more specifically in the hydrological changes associated with peat erosion and restoration. Peat restoration has often been cited as having potential benefits for downstream flood risk through the reduction of peak flows and increases in storm hydrograph lag times. However, evidence of the impacts of peatland restoration practices on storm hydrology and downstream discharge peaks has been limited by lack of measurement of flow response following restoration programmes. This paper reports a hydrological monitoring programme associated with the restoration of a blanket peatland in the Peak District, UK through the practices of erosion gully blocking and the re-vegetation of bare peat. The main component of the project is a before-after-control-impact (BACI) study on three hectare-scale eroded, bare peat catchments, two of which have been restored and one of which is acting as an unmodified control. Monitoring commenced in early summer 2010, and restoration of the experimental sites by reseeding and gully blocking took place between July 2011 and March 2012. To complement the main study, a broader spatial comparison of the hydrological behaviour of catchments with different degradation and restoration conditions has been made, including (i) an intact reference peatland, (ii) the eroded/bare peat sites, and (iii) a 'late stage' restored area of peatland which was re-vegetated in 2003. Results reveal significant differences between the storm hydrograph characteristics of intact, eroded and restored catchments consistent with the hypotheses that (a) peat erosion significantly decreases storm flow lag times and increases storm flow peaks in these peatland systems and (b) peat restoration reverses these effects. Associated overland flow data suggest that gully blocking and re-vegetation within gully systems are crucial controls on the storm hydrograph and peak flow responses. The study shows that peat restoration in upland blanket peat systems can contribute to the reduction of downstream flood risk.

  9. Spatial variation in concentrations of dissolved nitrogen species in an upland blanket peat catchment.

    PubMed

    Cundill, A P; Chapman, P J; Adamson, J K

    2007-02-01

    The concentration of nitrogen (N), particularly as nitrate (NO3-N), in upland streams, lakes and rivers is frequently used as a diagnostic of the vulnerability of upland ecosystems to increased atmospheric nitrogen deposition and N saturation. The N content of running waters, however, is generally assessed on the basis of sampling at a limited number of points in space and time within the catchment under investigation. The current study was conducted at Trout Beck, an 11.5 km2 blanket peat-dominated catchment in the North Pennine uplands of the UK. Results from sampling at 33 sites within this catchment demonstrated that the concentrations of all dissolved N species were highly variable, even over short distances. Statistical relationships between the concentrations of NO3-N and dissolved organic nitrogen (DON) and percentage catchment cover of Calluna/Eriophorum and Eriophorum vegetation were found. However, it was also noted that in catchments containing limestone outcrops, NO3-N concentration was much higher than in catchments where runoff was sourced directly from the blanket peat surface. It is possible that NH4-N and DON leached from the blanket peat are mineralised and nitrified, providing a source for the NO3-N found in the river channels. Overall, the current study suggests that interpretations of N-saturation based on river water chemistry measurements at a single point must be treated cautiously, and that the influence of catchment-scale physical factors, such as vegetation and geology cover on the concentration of dissolved N species in upland river waters should not be ignored. PMID:17182088

  10. A Digital Soil Mapping approach using neural networks for peat depth mapping in Scotland

    NASA Astrophysics Data System (ADS)

    Aitkenhead, Matt; Saunders, Matt; Yeluripati, Jagadeesh

    2014-05-01

    Spatially explicit and accurate peat depth estimates are required for carbon stock assessment, carbon management stategies , hydrological modelling, ecosystem service assessment and land management (e.g. wind farms). In Scotland, a number of surveys have taken place over the years that have produced data on peat depth, and while many of these surveys have focussed on specific locations or peat bogs, a substantial proportion of the data produced is relatively old and has not been digitised, thus limiting its visibility and utility in new research activities, policy development and land management decision making. Here we describe ongoing work where the key objective is to integrate multiple peat survey datasets with existing spatial datasets of climate, vegetation, topography and geology. The dataset produced is generated from a small number of isolated surveys and while it is not representative of all of Scotland's soils, it is sufficient to demonstrate the conceptual basis for model development. It has been used to develop a neural network model of peat depth that has been applied across Scotland's peat bogs at 100m resolution. The resulting map gives an early indication of the variation of peat depth across the country, and allows us to produce an estimate of mean peat bog depth across the country. This estimate will improve with additional data and will contribute to improving our ability to undertake activities that depend on this kind of information. We have identified data gaps that need to be addressed in order to improve this model, in particular peat depth survey data from a wider range of peat types across the country and in particular, blanket bog and upland peat areas. Ongoing work to identify and integrate additional peat bog depth data is described. We also identify potential uses for the existing maps of peat depth, and areas of future model development.

  11. Characterizing Pb mobilization from upland soils to streams using (206)Pb/(207)Pb isotopic ratios.

    PubMed

    Dawson, Julian J C; Tetzlaff, Doerthe; Carey, Anne-Marie; Raab, Andrea; Soulsby, Chris; Killham, Kenneth; Meharg, Andrew A

    2010-01-01

    Anthropogenically deposited lead (Pb) binds efficiently to soil organic matter, which can be mobilized through hydrologically mediated mechanisms, with implications for ecological and potable quality of receiving waters. Lead isotopic ((206)Pb/(207)Pb) ratios change down peat profiles as a consequence of long-term temporal variation in depositional sources, each with distinctive isotopic signatures. This study characterizes differential Pb transport mechanisms from deposition to streams at two small catchments with contrasting soil types in upland Wales, U.K., by determining Pb concentrations and (206)Pb/(207)Pb ratios from soil core profiles, interstitial pore waters, and stream water. Hydrological characteristics of soils are instrumental in determining the location in soil profiles of exported Pb and hence concentration and (206)Pb/(207)Pb ratios in surface waters. The highest Pb concentrations from near-surface soils are mobilized, concomitant with high dissolved organic carbon (DOC) exports, from hydrologically responsive peat soils with preferential shallow subsurface flows, leading to increased Pb concentrations in stream water and isotopic signatures more closely resembling recently deposited Pb. In more minerogenic soils, percolation of water allows Pb, bound to DOC, to be retained in mineral horizons and combined with other groundwater sources, resulting in Pb being transported from throughout the profile with a more geogenic isotopic signature. This study shows that (206)Pb/(207)Pb ratios can enhance our understanding of the provenances and transport mechanisms of Pb and potentially organic matter within upland soils. PMID:19954181

  12. Metatranscriptomic Analysis of Arctic Peat Soil Microbiota

    PubMed Central

    Tveit, Alexander T.

    2014-01-01

    Recent advances in meta-omics and particularly metatranscriptomic approaches have enabled detailed studies of the structure and function of microbial communities in many ecosystems. Molecular analyses of peat soils, ecosystems important to the global carbon balance, are still challenging due to the presence of coextracted substances that inhibit enzymes used in downstream applications. We sampled layers at different depths from two high-Arctic peat soils in Svalbard for metatranscriptome preparation. Here we show that enzyme inhibition in the preparation of metatranscriptomic libraries can be circumvented by linear amplification of diluted template RNA. A comparative analysis of mRNA-enriched and nonenriched metatranscriptomes showed that mRNA enrichment resulted in a 2-fold increase in the relative abundance of mRNA but biased the relative distribution of mRNA. The relative abundance of transcripts for cellulose degradation decreased with depth, while the transcripts for hemicellulose debranching increased, indicating that the polysaccharide composition of the peat was different in the deeper and older layers. Taxonomic annotation revealed that Actinobacteria and Bacteroidetes were the dominating polysaccharide decomposers. The relative abundances of 16S rRNA and mRNA transcripts of methanogenic Archaea increased substantially with depth. Acetoclastic methanogenesis was the dominating pathway, followed by methanogenesis from formate. The relative abundances of 16S rRNA and mRNA assigned to the methanotrophic Methylococcaceae, primarily Methylobacter, increased with depth. In conclusion, linear amplification of total RNA and deep sequencing constituted the preferred method for metatranscriptomic preparation to enable high-resolution functional and taxonomic analyses of the active microbiota in Arctic peat soil. PMID:25015892

  13. Metatranscriptomic analysis of arctic peat soil microbiota.

    PubMed

    Tveit, Alexander T; Urich, Tim; Svenning, Mette M

    2014-09-01

    Recent advances in meta-omics and particularly metatranscriptomic approaches have enabled detailed studies of the structure and function of microbial communities in many ecosystems. Molecular analyses of peat soils, ecosystems important to the global carbon balance, are still challenging due to the presence of coextracted substances that inhibit enzymes used in downstream applications. We sampled layers at different depths from two high-Arctic peat soils in Svalbard for metatranscriptome preparation. Here we show that enzyme inhibition in the preparation of metatranscriptomic libraries can be circumvented by linear amplification of diluted template RNA. A comparative analysis of mRNA-enriched and nonenriched metatranscriptomes showed that mRNA enrichment resulted in a 2-fold increase in the relative abundance of mRNA but biased the relative distribution of mRNA. The relative abundance of transcripts for cellulose degradation decreased with depth, while the transcripts for hemicellulose debranching increased, indicating that the polysaccharide composition of the peat was different in the deeper and older layers. Taxonomic annotation revealed that Actinobacteria and Bacteroidetes were the dominating polysaccharide decomposers. The relative abundances of 16S rRNA and mRNA transcripts of methanogenic Archaea increased substantially with depth. Acetoclastic methanogenesis was the dominating pathway, followed by methanogenesis from formate. The relative abundances of 16S rRNA and mRNA assigned to the methanotrophic Methylococcaceae, primarily Methylobacter, increased with depth. In conclusion, linear amplification of total RNA and deep sequencing constituted the preferred method for metatranscriptomic preparation to enable high-resolution functional and taxonomic analyses of the active microbiota in Arctic peat soil. PMID:25015892

  14. Climate mitigation scenarios of drained peat soils

    NASA Astrophysics Data System (ADS)

    Kasimir Klemedtsson, Åsa; Coria, Jessica; He, Hongxing; Liu, Xiangping; Nordén, Anna

    2014-05-01

    The national inventory reports (NIR) submitted to the UNFCCC show Sweden - which as many other countries has wetlands where parts have been drained for agriculture and forestry purposes, - to annually emit 12 million tonnes carbon dioxide equivalents, which is more GHG'es than industrial energy use release in Sweden. Similar conditions can be found in other northern countries, having cool and wet conditions, naturally promoting peat accumulation, and where land use management over the last centuries have promoted draining activities. These drained peatland, though covering only 2% of the land area, have emissions corresponding to 20% of the total reported NIR emissions. This substantial emission contribution, however, is hidden within the Land Use Land Use Change and Forestry sector (LULUCF) where the forest Carbon uptake is even larger, which causes the peat soil emissions become invisible. The only drained soil emission accounted in the Swedish Kyoto reporting is the N2O emission from agricultural drained organic soils of the size 0.5 million tonnes CO2e yr-1. This lack of visibility has made incentives for land use change and management neither implemented nor suggested, however with large potential. Rewetting has the potential to decrease soil mineralization, why CO2 and N2O emissions are mitigated. However if the soil becomes very wet CH4 emission will increase together with hampered plant growth. By ecological modeling, using the CoupModel the climate change mitigation potential have been estimated for four different land use scenarios; 1, Drained peat soil with Spruce (business as usual scenario), 2, raised ground water level to 20 cm depth and Willow plantation, 3, raised ground water level to 10 cm depth and Reed Canary Grass, and 4, rewetting to an average water level in the soil surface with recolonizing wetland plants and mosses. We calculate the volume of biomass production per year, peat decomposition, N2O emission together with nitrate and DOC/POC leakage. Based on the modelling results a cost benefit analysis is performed (economics), guiding to the design of environmental policies needed for land use change to come true.

  15. 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.

  16. INFLUENCE OF REDOX ON THE RHIZOSPHERE CHEMISTRY OF UPLAND SOILS

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Many upland soils in the Midwest of the US are temporally flooded during the Spring. These soils can remain water saturated for days, weeks, or even months. The effects of prolonged saturation on the biogeochemical processes that occur in these soils are not fully understood and are the subject of...

  17. A 19-year long energy budget of an upland peat bog, northern England

    NASA Astrophysics Data System (ADS)

    Worrall, Fred; Clay, Gareth; Moody, Catherine; Burt, Timothy

    2015-04-01

    This study has estimated the long term evaporation record for a peat covered catchment in northern England. In this study, 19 years of daily evaporation were estimated for rain-free periods using White's methods. Net radiation was measured over the study period; soil heat flux was calculated from temperature profiles; and sensible heat flux was calculated assuming the energy budget was closed. The calculated time series was compared to available environmental information on the same time step and over the same time period. Over a 19-year period it was possible to calculate 1662 daily evaporation rates (26% of the period). The study showed that the energy flux to net primary productivity was a small, long-term sink of energy but this sink was a virtue of high carbon accumulation in peat catchments: in catchments where there is no long-term dry matter accumulation, net primary productivity must be a small net source of energy. The study showed that evaporation increased over the study period whilst sensible heat flux significantly declined with the ecosystem became a stronger heat sink reflecting an increased use of sensible heat energy to meet evaporative demand. The relatively small change in evaporative flux compared to other energy fluxes suggests that this system is a "near-equilibrium" system and not a "far-from-equilibrium" system.

  18. The Influence of Dam Removal on Upland Soils

    NASA Astrophysics Data System (ADS)

    Lafrenz, M. D.; Bean, R. A.; Uthman, D.

    2011-12-01

    Driven largely by anadromous fish passage issues, several dams have been removed in the Pacific Northwest and several more are slated to be removed there and in other regions of North America. While much effort has gone into modeling and monitoring the geomorphic and ecologic response of stream channels to dam removal, little research has investigated changes in upland soils following inundation resulting from dam construction, and none had evaluated how these upland soils would respond to dewatering following dam removal. The removal of a relatively large dam - Marmot Dam on the Sandy River in Northwest Oregon, presented an opportunity to evaluate the effect of dewatering on what were formerly upland rather than floodplain soils. We compared the dewatered soils to downstream upland soils that had not been inundated and modified a "ripening" index, which had been developed to characterize dewatered estuary soils in Dutch polders, in order to evaluate the physical and chemical changes taking place in these soils. Two years following dam removal, the previously inundated soils have higher organic matter percentage, cation exchange capacity, and nitrogen levels than downstream soils that were not inundated; yet, this new riparian area is largely devoid of vegetation while the downstream soils maintain a thick (10 cm) O horizon. The carbon to nitrogen ratios (C:N) of upstream surface horizons are low (13:1) and increase markedly with soil depth (54:1); the C:N ratios of downstream soils are typical of other forested soils in this region (28:1 at the surface and 26:1 at depth). Prior to dam removal, it is likely that all upstream, inundated soils had high C:N ratios due to the persistent anaerobic conditions under the reservoir. Following dam removal, soil microbes needing to supplement their nitrogen consumption with soluble nitrogen likely out-competed higher plants for plant available nitrogen. The C:N ratio should have dropped to an equilibrium; this was not achieved at this location likely due to the coarse texture and corresponding low ripening value of the dewatered soils. Hence, native plants have not re-established in the new riparian area. The current resulting high levels of nitrogen in the upstream dewatered soil is anomalous for this region and could lead to colonization by non-native species in this and other newly dewatered ecosystems. Additionally, the lower sections of the dewatered upland soils are still saturated even though they stand perched several meters above the current floodplain; this evidence of reservoir "underflooding" will continue to affect soil development for an unknown amount of time and should be considered for any large dam removal project.

  19. Organic matter loss from cultivated peat soils in Sweden

    NASA Astrophysics Data System (ADS)

    Berglund, Örjan; Berglund, Kerstin

    2015-04-01

    The degradation of drained peat soils in agricultural use is an underestimated source of loss of organic matter. Oxidation (biological degradation) of agricultural peat soils causes a loss of organic matter (OM) of 11 - 22 t ha-1 y-1 causing a CO2 emission of 20 - 40 t ha-1 y-1. Together with the associated N2O emissions from mineralized N this totals in the EU to about 98.5 Mton CO2 eq per year. Peat soils are very prone to climate change and it is expected that at the end of this century these values are doubled. The degradation products pollute surface waters. Wind erosion of peat soils in arable agriculture can cause losses of 3 - 30 t ha-1 y-1 peat also causing air pollution (fine organic particles). Subsidence rates are 1 - 2 cm per year which leads to deteriorating drainage effect and make peat soils below sea or inland water levels prone to flooding. Flooding agricultural peat soils is in many cases not possible without high costs, high GHG emissions and severe water pollution. Moreover sometimes cultural and historic landscapes are lost and meadow birds areas are lost. In areas where the possibility to regulate the water table is limited the mitigation options are either to increase biomass production that can be used as bioenergy to substitute some fossil fuel, try to slow down the break-down of the peat by different amendments that inhibit microbial activity, or permanent flooding. The negative effects of wind erosion can be mitigated by reducing wind speed or different ways to protect the soil by crops or fiber sheets. In a newly started project in Sweden a typical peat soil with and without amendment of foundry sand is cropped with reed canary grass, tall fescue and timothy to investigate the yield and greenhouse gas emissions from the different crops and how the sand effect the trafficability and GHG emissions.

  20. Investigating the impact of land cover change on peak river flow in UK upland peat catchments, based on modelled scenarios

    NASA Astrophysics Data System (ADS)

    Gao, Jihui; Holden, Joseph; Kirkby, Mike

    2014-05-01

    Changes to land cover can influence the velocity of overland flow. In headwater peatlands, saturation means that overland flow is a dominant source of runoff, particularly during heavy rainfall events. Human modifications in headwater peatlands may include removal of vegetation (e.g. by erosion processes, fire, pollution, overgrazing) or pro-active revegetation of peat with sedges such as Eriophorum or mosses such as Sphagnum. How these modifications affect the river flow, and in particular the flood peak, in headwater peatlands is a key problem for land management. In particular, the impact of the spatial distribution of land cover change (e.g. different locations and sizes of land cover change area) on river flow is not clear. In this presentation a new fully distributed version of TOPMODEL, which represents the effects of distributed land cover change on river discharge, was employed to investigate land cover change impacts in three UK upland peat catchments (Trout Beck in the North Pennines, the Wye in mid-Wales and the East Dart in southwest England). Land cover scenarios with three typical land covers (i.e. Eriophorum, Sphagnum and bare peat) having different surface roughness in upland peatlands were designed for these catchments to investigate land cover impacts on river flow through simulation runs of the distributed model. As a result of hypothesis testing three land cover principles emerged from the work as follows: Principle (1): Well vegetated buffer strips are important for reducing flow peaks. A wider bare peat strip nearer to the river channel gives a higher flow peak and reduces the delay to peak; conversely, a wider buffer strip with higher density vegetation (e.g. Sphagnum) leads to a lower peak and postpones the peak. In both cases, a narrower buffer strip surrounding upstream and downstream channels has a greater effect than a thicker buffer strip just based around the downstream river network. Principle (2): When the area of change is equal, the size of land cover change patches has no effect on river flow for patch sizes up to 40000m2. Principle (3): Bare peat on gentle slopes gives a faster flow response and higher peak value at the catchment outlet, while high density vegetation or re-vegetation on a gentle slope area has larger positive impact on peak river flow delay when compared with the same practices on steeper slopes. These simple principles should be useful to planners who wish to determine resource efficiency and optimisation for peatland protection and restoration works in headwater systems. If practitioners require further detail on impacts of specific spatial changes to land cover in a catchment then this modelling approach can be applied to new catchments of concern.

  1. Peat

    USGS Publications Warehouse

    Jasinski, S.M.

    2006-01-01

    In 2005, peat was harvested in 15 US states. Florida, Michigan and Minnesota accounted for more than 80% of the US production. Reed-sedge was the dominant variety of peat harvested in the United States. More than 56% of all peat used in the US was imported from Canada. With the growing interest in gardening, landscaping related to home construction and golf courses, peat usage is expected to remain near current levels during the next several years.

  2. High potential for iron reduction in upland soils.

    PubMed

    Yang, Wendy H; Liptzin, Daniel

    2015-07-01

    Changes in the redox state of iron (Fe) can be coupled to the biogeochemical cycling of carbon (C), nitrogen, and phosphorus, and thus regulate soil C, ecosystem nutrient availability, and greenhouse gas production. However, its importance broadly in non-flooded upland terrestrial ecosystems is unknown. We measured Fe reduction in soil samples from an annual grassland, a drained peatland, and a humid tropical forest We incubated soil slurries in an anoxic glovebox for 5.5 days and added sodium acetate daily at rates up to 0.4 mg C x (g soil)(-1) x d(-1). Soil moisture, poorly crystalline Fe oxide concentrations, and Fe(II) concentrations differed among study sites in the following order: annual grassland < drained peatland < tropical forest (P < 0.001 for all characteristics). All of the soil samples demonstrated high Fe reduction potential with maximum rates over the course of the incubation averaging 1706 66, 2016 12, and 2973 115 ?g Fe x (g soil)(-1) x d(-1) (mean SE) for the tropical forest, annual grassland, and drained peatland, respectively. Our results suggest that upland soils from diverse ecosystems have the potential to exhibit high short-term rates of Fe reduction that may play an important role in driving soil biogeochemical processes during periods of anaerobiosis. PMID:26378323

  3. Diversity and Activity of Methanotrophic Bacteria in Different Upland Soils

    PubMed Central

    Knief, Claudia; Lipski, Andr; Dunfield, Peter F.

    2003-01-01

    Samples from diverse upland soils that oxidize atmospheric methane were characterized with regard to methane oxidation activity and the community composition of methanotrophic bacteria (MB). MB were identified on the basis of the detection and comparative sequence analysis of the pmoA gene, which encodes a subunit of particulate methane monooxygenase. MB commonly detected in soils were closely related to Methylocaldum spp., Methylosinus spp., Methylocystis spp., or the forest sequence cluster (USC ?), which has previously been detected in upland soils and is related to pmoA sequences of type II MB (Alphaproteobacteria). As well, a novel group of sequences distantly related (<75% derived amino acid identity) to those of known type I MB (Gammaproteobacteria) was often detected. This novel upland soil cluster ? (USC ?) was significantly more likely to be detected in soils with pH values of greater than 6.0 than in more acidic soils. To identify active MB, four selected soils were incubated with 13CH4 at low mixing ratios (<50 ppm of volume), and extracted methylated phospholipid fatty acids (PLFAs) were analyzed by gas chromatography-online combustion isotope ratio mass spectrometry. Incorporation of 13C into PLFAs characteristic for methanotrophic Gammaproteobacteria was observed in all soils in which USC ? sequences were detected, suggesting that the bacteria possessing these sequences were active methanotrophs. A pattern of labeled PLFAs typical for methanotrophic Alphaproteobacteria was obtained for a sample in which only USC ? sequences were detected. The data indicate that different MB are present and active in different soils that oxidize atmospheric methane. PMID:14602631

  4. Laboratory evaporation experiments in undisturbed peat columns for determining peat soil hydraulic properties

    NASA Astrophysics Data System (ADS)

    Dettmann, U.; Frahm, E.; Bechtold, M.

    2013-12-01

    Knowledge about hydraulic properties of organic soils is crucial for the interpretation of the hydrological situation in peatlands. This in turn is the basis for designing optimal rewetting strategies, for assessing the current and future climatic water balance and for quantifying greenhouse gas emissions of CO2, CH4 and N2O, which are strongly controlled by the depth of the peat water table. In contrast to mineral soils, the hydraulic properties of organic soils differ in several aspects. Due to the high amount of organic components, strong heterogeneity, and shrinkage and swelling of peat, accompanied by changing soil volume and bulk density, the applicability of standard hydraulic functions developed for mineral soils for describing peat soil moisture dynamics is often questioned. Hence, the objective of this study was to investigate the applicability of the commonly applied van Genuchten-Mualem (VGM) parameterization and to evaluate model errors for various peat types. Laboratory column experiments with undisturbed peat soils (diameter: 30 cm, height: 20 cm) from 5 different peatlands in Germany were conducted. In numerical simulations using HYDRUS-1D the experimental data were used for an inverse estimation of the soil hydraulic parameters. Using the VGM parameterization, the model errors between observed and measured pressure heads were quantified with a root mean square error (RMSE) of 20 - 65 cm. The RMSE increased for soils with higher organic carbon content and higher porosity. Optimizing the VGM 'tortuosity' parameter (?) instead of fixing it to its default of 0.5 strongly reduced the RMSE, especially for the soils that showed high pressure head gradients during the experiment. Due to the fact, that very negative pressure heads in peatlands occur rarely, we reduced the range of pressured heads in the inversion to a 'field-relevant' range from 0 to -200 cm which strongly reduced the RMSE to 6 - 12 cm and makes the VGM parameterization applicable for all investigated peat soils. For the field-relevant scale, especially for very wet conditions, we demonstrate the importance of macro-pores by using a simple macro-pore approach, with only 1 additional parameter, i.e. the macro-pore fraction, which strongly reduced the RMSE down to 1 - 7 cm. Since ? has not been identified as an important parameter for the field-relevant range, only 5 parameters were optimized in this approach. This keeps the derivation of the parameters manageable and thus provides a model that is applicable to practical issues.

  5. Deccesion of peat-moorsh soils under different land use

    NASA Astrophysics Data System (ADS)

    Lipka, K.; Zaj?c, E.

    2009-04-01

    Use of peatlands has a serious impact on soil properties as well as on loss of organic matter. On the basis of survey carried out in 1976, 1993 and 2001 in the Mrowla river valley near Rzeszow, authors analysed changes of the peat-moorsh soils under different land use. The 25- year period was analysed. Survey results comprised: loss of organic matter, advance of moorsh forming process and change of prognostic soil-moisture complexes (after Okruszko). Stratigraphic profiles made in the years1996-2001 were compared and rate of organic mass loss was calculated. The highest values were stated for ploughfields with crop rotation (root plants, industrial plants and cereals). Intensified soil aeration and moorsh forming process as well as wind erosion caused gradual lowering of ground level. Depth of degraded peat layer in roof of surveyed peat deposits was between 0,2 and 0,8 m. Ground surface was lowering of 1,68 cm per year. It was found that, for ploughfields especially, peat-moorhs soil showing medium degree of moorsh forming process (MtII) and prognostic soil-moisture complex BC (periodically drying), after 17 years already, had changed into a soil with high degree of moorsh forming process (MtIII) and prognostic soil-moisture complex C (drying). For meadows and pastures land used such evident change wasn't noticed. During the whole investigation period (25 years) mean lowering of the peat-moorsh soils level along transects lines for different land use was: 1,15 cm per year for meadows and pastures, 1,58 cm pea year for plougfields and 1,38 cm per year for alder wood.

  6. The lignin content in virgin and cultivated peat soils of Belarussian poles'e

    NASA Astrophysics Data System (ADS)

    Bambalov, N. N.

    2007-11-01

    The contents of lignin extracted by a mixture of dioxane, water, and hydrochloric acid was determined in peat-forming plants (moss, herbaceous, and woody) corresponding to types of peat, cultivated and virgin peat soils, and stubby barley residues. The balance experiments in the field and in the laboratory over 12 36 months showed that, upon the decomposition of the peat-forming plants, the part of lignin available for microorganisms was humified and mineralized, while the unavailable part accumulated in the peat. A close correlation was revealed between the lignin content in the peat-forming plants and the humic acid concentration in the peat. Upon agricultural use, the lignin content in the plow horizons of the peat soils did not change if the degree of the peat decomposition was identical to that in the virgin soils or if it was higher by 2 2.5% if the peat decomposition rate increased.

  7. Peat

    USGS Publications Warehouse

    Jasinski, S.M.

    2000-01-01

    The United States continued to be significant producer and consumer of peat for horticultural and industrial applications in 1999. Florida, Michigan and Minnesota were the largest producing states, in order of output.

  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. Phenol oxidase activity in secondary transformed peat-moorsh soils

    NASA Astrophysics Data System (ADS)

    Sty?a, K.; Szajdak, L.

    2009-04-01

    The chemical composition of peat depends on the geobotanical conditions of its formation and on the depth of sampling. The evolution of hydrogenic peat soils is closely related to the genesis of peat and to the changes in water conditions. Due to a number of factors including oscillation of ground water level, different redox potential, changes of aerobic conditions, different plant communities, and root exudes, and products of the degradation of plant remains, peat-moorsh soils may undergo a process of secondary transformation conditions (Sokolowska et al. 2005; Szajdak et al. 2007). Phenol oxidase is one of the few enzymes able to degrade recalcitrant phenolic materials as lignin (Freeman et al. 2004). Phenol oxidase enzymes catalyze polyphenol oxidation in the presence of oxygen (O2) by removing phenolic hydrogen or hydrogenes to from radicals or quinines. These products undergo nucleophilic addition reactions in the presence or absence of free - NH2 group with the eventual production of humic acid-like polymers. The presence of phenol oxidase in soil environments is important in the formation of humic substances a desirable process because the carbon is stored in a stable form (Matocha et al. 2004). The investigations were carried out on the transect of peatland 4.5 km long, located in the Agroecological Landscape Park host D. Chlapowski in Turew (40 km South-West of Pozna?, West Polish Lowland). The sites of investigation were located along Wysko? ditch. The following material was taken from four chosen sites marked as Zbechy, Bridge, Shelterbelt and Hirudo in two layers: cartel (0-50cm) and cattle (50-100cm). The object of this study was to characterize the biochemical properties by the determination of the phenol oxidize activity in two layers of the four different peat-moors soils used as meadow. The phenol oxidase activity was determined spectrophotometrically by measuring quinone formation at ?max=525 nm with catechol as substrate by method of Perucci et al. (2000). In peat the highest activities of phenol oxidase was observed in the combinations marked as Shelterbelt and whereas the lowest - in Zbechy, Bridge and Hirudo. Activities of this enzyme in peat ranged from 15.35 to 38.33 ?mol h-1g d.m soil. Increased activities of phenol oxidase have been recorded on the depth 50-100cm - catotelm (21.74-38.33 ?mol h-1g d.m soil) in comparison with the depth 0-50cm - acrotelm (15.35-28.32 ?mol h-1g d.m soil). References Freeman, C., Ostle N.J., Fener, N., Kang H. 2004. A regulatory role for phenol oxidase during decomposition in peatlands. Soil Biology and Biochemistry, 36, 1663-1667. Matocha Ch.J., Haszler G.R., Grove J.H. 2004. Nitrogen fertilization suppresses soil phenol oxidase enzyme activity in no-tillage systems. Soil Science, 169/10, 708-714. Perucci P., Casucci C., Dumontet S. 2000. An improved method to evaluate the o-diphenol oxidase activity of soil. Soil Biology and Biochemistry, 32, 1927-1933. Sokolowska Z., Szajdak L., Matyka-Sarzy?ska D. 2005. Impact of the degree of secondary transformation on amid-base properties of organic compounds in mucks. Geoderma, 127, 80-90. Szajdak L., Szczepa?ski M., Bogacz A. 2007. Impact of secondary transformation of peat-moorsh soils on the decrease of nitrogen and carbon compounds in ground water. Agronomy Research, 5/2, 189-200.

  10. Peat

    USGS Publications Warehouse

    Jasinski, S.M.

    1998-01-01

    The United States continued as a significant producer and consumer of peat for horticultural, agricultural and industrial applications in 1997. Several operations in the Great Lakes and the Southeast regions dominated US production. Florida, Michigan and Minnesota were the largest producing states.

  11. Peat

    USGS Publications Warehouse

    Jasinski, S.M.

    2003-01-01

    Peat is a natural organic material of botanical origin and commercial significance. Peatlands are situated predominately in shallow wetland areas of the Northern Hemisphere. Commercial deposits are formed from the gradual decomposition of plant matter under anaerobic conditions over about a 5,000-year period.

  12. Peat fires as source of polycyclic aromatic hydrocarbons in soils

    NASA Astrophysics Data System (ADS)

    Tsibart, Anna

    2013-04-01

    Polycyclic aromatic hydrocarbons (PAHs) arrive from pyrogenic sources including volcanism and the combustion of oil products and plant materials. The production of PAHs during the combustion of plant materials was considered in a number of publications, but their results were mainly obtained in laboratory experiments. Insufficient data are available on the hightemperature production of PAHs in environmental objects. For example, natural fires are frequently related to the PAH sources in landscapes, but very little factual data are available on this topic. On Polistovskii reserve (Russia, Pskov region) the soil series were separated depending on the damage to the plants; these series included soils of plots subjected to fires of different intensities, as well as soils of the background plots. The series of organic and organomineral soils significantly differed in their PAH distributions. In this series, the concentration of PAHs in the upper horizons of the peat soils little varied or slightly decreased, but their accumulation occurred at a depth of 5-10 or 10-20 cm in the soils after the fires. For example, in the series of high moor soils, the content of PAHs in the upper horizons remained almost constant; significant differences were observed in the subsurface horizons: from 2 ng/g in the background soil to 70 ng/g after the fire. In the upper horizons of the oligotrophic peat soils under pine forests, the total PAH content also varied only slightly. At the same time, the content of PAHs in the soil series increased from 15 to 90 ng/g with the increasing pyrogenic damage to the plot. No clear trends of the PAH accumulation were recorded in the organomineral soils. The content of PAHs in the soddy-podzolic soil subjected to fire slightly decreased (from 20 to 10 ng/g) compared to the less damaged soil. In peat fires, the access of oxygen to the fire zone is lower than in forest fires. The oxygen deficit acts as a factor of the organic fragments recombination and PAH production; therefore, larger amounts of PAHs are formed in peat fires. In addition, the peat fires occur directly in the soil layer; therefore, larger amounts of the resulting polyarenes remain in the soils of the fire sites. PAHs also can be formed at the heating of organic matter on the areas adjacent to the fire sites. After the combustion of peat in fires, phenanthrene, chrysene, benz[a]pyrene, and tetraphene accumulate in soils. This is mainly the group of 4-nuclear compounds with the participation of 3-nuclear phenanthrene and 5-nuclear benz[a]pyrene. The formation of high-molecular weight compounds like benz[a]pyrene and, in some places, benzo[ghi]perylene is possible during smoldering under a low oxygen supply.

  13. Changes in sulphate retention, soil chemistry and drainage water quality along an upland soil transect.

    PubMed

    Sanger, L J; Billett, M F; Cresser, M S

    1994-01-01

    Soils sampled along an altitudinal transect in an upland area of North East Scotland have been used to investigate downslope changes in the capacity of soils to retain sulphate. Simulated laboratory experiments involving the leaching of reconstituted cores with 'rainfall' containing low (1.85 mg litre(-1) and high (51.90 mg litre(-1) concentrations of sulphate indicate that soils developed on upper slopes have a limited capacity to adsorb sulphate, whereas soils on lower slopes have a much greater sulphate adsorption capacity. Soil drainage water, produced from 'sensitive' upper slope soils may therefore be significantly modified by physico-chemical reactions in lower slopes before reaching watercourses. PMID:15091628

  14. Suitability of field portable XRF for the study of contaminated peat soils

    NASA Astrophysics Data System (ADS)

    Shuttleworth, E. L.; Evans, M. G.; Rothwell, J. J.; Hutchinson, S. M.

    2012-04-01

    Upland peat soils in close proximity to urban and industrial areas can be contaminated with - and act as sinks for - high concentrations of atmospherically deposited lead. Erosion of these soils has the potential to release lead to surface waters. Lead storage is not uniform across peat surfaces and significant within-site spatial variability has previously been found. In heavily degraded areas this is further complicated by gullying and the removal of surface material from bare peat flats. Quantifying lead concentrations across the surface of actively eroding peatlands is vital in order to understand lead storage and release in such systems. Field portable x-ray fluorescence (FPXRF) continues to gain acceptance in the study of metal contaminated soil; however, FPXRF has not been used to conduct field surveys of contaminated peat soils due to their high moisture content. FPXRF analysers allow a large number of samples to be processed in a relatively short time giving a high level of detail with little disturbance to the surrounding area. They also offer significant advantages over off-site laboratory analysis in terms of on-site decision making and faster turn-around of results. This study compares lead concentration data obtained in situ using a handheld Niton XL3t 900 X-Ray Fluorescence analyser with data derived from ex situ lab based analyses. In situ measurements were acquired across degraded and intact peatland sites in the Peak District, southern Pennines, UK. Field samples were then dried, homogenised and analysed again using the FPXRF before subsequent acid digestion and analysis using inductively coupled plasma atomic emission spectroscopy (ICP-OES). The moisture content of the samples was also determined and used to normalise the in situ field measurements. A good relationship was found between in situ and ex situ lead concentration data. Linear regression analysis yielded r2 values of 0.80 (in situ XRF vs. ICP-OES) and 0.82 (in situ XRF vs. ex situ XRF). These are improved slightly when in situ concentrations are normalised for moisture content. This study reveals that FPXRF can provide an accurate, rapid and cost-effective means of assessing surface lead content in contaminated peatland environments.

  15. Biological Chlorine Cycling in Arctic Peat Soils

    NASA Astrophysics Data System (ADS)

    Zlamal, J. E.; Raab, T. K.; Lipson, D.

    2014-12-01

    Soils of the Arctic tundra near Barrow, Alaska are waterlogged and anoxic throughout most of the profile due to underlying permafrost. Microbial communities in these soils are adapted for the dominant anaerobic conditions and are capable of a surprising diversity of metabolic pathways. Anaerobic respiration in this environment warrants further study, particularly in the realm of electron cycling involving chlorine, which preliminary data suggest may play an important role in arctic anaerobic soil respiration. For decades, Cl was rarely studied outside of the context of solvent-contaminated sites due to the widely held belief that it is an inert element. However, Cl has increasingly become recognized as a metabolic player in microbial communities and soil cycling processes. Organic chlorinated compounds (Clorg) can be made by various organisms and used metabolically by others, such as serving as electron acceptors for microbes performing organohalide respiration. Sequencing our arctic soil samples has uncovered multiple genera of microorganisms capable of participating in many Cl-cycling processes including organohalide respiration, chlorinated hydrocarbon degradation, and perchlorate reduction. Metagenomic analysis of these soils has revealed genes for key enzymes of Cl-related metabolic processes such as dehalogenases and haloperoxidases, and close matches to genomes of known organohalide respiring microorganisms from the Dehalococcoides, Dechloromonas, Carboxydothermus, and Anaeromyxobacter genera. A TOX-100 Chlorine Analyzer was used to quantify total Cl in arctic soils, and these data were examined further to separate levels of inorganic Cl compounds and Clorg. Levels of Clorg increased with soil organic matter content, although total Cl levels lack this trend. X-ray Absorption Near Edge Structure (XANES) was used to provide information on the structure of Clorg in arctic soils, showing great diversity with Cl bound to both aromatic and alkyl groups. Incubations were conducted in the laboratory providing arctic soils with Clorg, and measurements taken to assess rates of organohalide respiration show an increase in chloride production due to microbial activity. Investigating these soils with diverse techniques affirms the importance of Cl-cycling in a pristine arctic tundra ecosystem.

  16. Effect of soil properties on peat erosion and suspended sediment delivery in drained peatlands

    NASA Astrophysics Data System (ADS)

    Tuukkanen, Tapio; Marttila, Hannu; Klve, Bjrn

    2014-04-01

    Erosion from peat extraction areas is known to cause siltation of water courses and poor water quality. However, the main soil parameters affecting peat erosion and suspended sediment (SS) yields from different catchments are not well understood. This paper used peat properties (degree of humification, peat type, ash content, porosity, moisture content, bulk density, and shear strength) and novel erosion threshold measurements from intact soil cores to explain peat erodibility and spatial variations in SS concentrations (SSCs) and SS loads (SSLs) at 20 Finnish peat extraction sites. The erosion threshold measurements suggested that critical shear stresses for particle entrainment decrease with increasing degree of humification (von Post scale) and are significantly lower in well-decomposed peat than in slightly or moderately decomposed peat. Two critical shear stresses were obtained from moderately decomposed peat samples, indicating a degree of surface armoring by coarse peat fibers. Monitored long-term average SSC was highest at study sites with well-decomposed peat, while very fine-grained mineral subsoil explained some of the highest long-term SSC in areas where drainage ditches penetrated below the upper peat layer. Average SSL (kg d-1) at the study sites was best explained (R2 = 0.89) by average discharge and surface peat decomposition level. Overall, this study provides new knowledge on peat erosion and critical shear stresses that can be used in water conservation and sediment management practices for cutover peatlands and other similar land uses.

  17. Projected irrigation requirements for upland crops using soil moisture model under climate change in South Korea

    Technology Transfer Automated Retrieval System (TEKTRAN)

    An increase in abnormal climate change patterns and unsustainable irrigation in uplands cause drought and affect agricultural water security, crop productivity, and price fluctuations. In this study, we developed a soil moisture model to project irrigation requirements (IR) for upland crops under cl...

  18. Is the blocking of drainage channels in upland peats an effective means of reducing DOC loss at the catchment scale?

    NASA Astrophysics Data System (ADS)

    Turner, Kate; Worrall, Fred

    2010-05-01

    Only 3% of the earths land surface is covered by peatland yet boreal and subarctic peatlands store approximately 15-30% of the World's soil carbon as peat (Limpens et al. 2008). In comparison British bogs store carbon equivalent to 20 years worth of national emissions. The loss of carbon from these areas in the form of dissolved organic carbon (DOC) is increasing and it is expected to have grown by up to 40% by 2018. Extensive drainage of UK peatlands has been associated with dehydration of the peat, an increase in water colour and a loss of carbon storage. It has been considered that the blocking of these drainage channels represents a means of peat restoration and a way of reducing DOC loss. This study aims to assess the effectiveness of this drain blocking at both an individual drain scale and at a larger catchment scale. Gibson et al. (2009) considered the effects of blocking at a solely individual drain scale finding that a 20% drop in DOC export was recorded post blocking however this decrease was due to a reduction in water yield rather than a reduction in DOC concentration with the concentration record showing no significant reduction. The effect of external parameters become more pronounced as the DOC record is examined at larger scales. The catchment is an open system and water chemistry will be influence by mixing with water from other sources. Also it is likely that at some point the drains will cut across slope leading to the flow of any highly coloured water down slope, bypassing the blockages, and entering the surface waters downstream. Degradation of DOC will occur naturally downstream due to the effects of light and microbial activity. There is, consequently, a need to examine the wider effects of drain blocking at a catchment scale to ensure that what is observed for one drain transfers to the whole catchment. A series of blocked and unblocked catchments were studied in Upper Teesdale, Northern England. Drain water samples were taken at least daily at nine localities. These sites were located such that individual drains could be monitored in the context of a larger catchment. Water table depth, flow and weather parameters were recorded along with the collection of runoff and soil water samples. A detailed sampling programme was undertaken in which a series of drains were studied in the 12 months prior to and post blocking. This approach has allowed the effects of blocking on the carbon budget, water balance and flow pathways to be considered. Results indicate that the blocking of zero order drainage channels leads to a decrease in DOC export on an individual drain scale. However, this is due to a reduction in water yield rather than concentration. Concentrations are seen to rise by a small yet statistically significant amount in blocked zero order streams. The effect at a larger scale is more complex. Annual export values in the unblocked control catchment show a rise from zero to first order streams indicating that water is being added to the system at this scale from external spatially variable sources. This pattern is also recognised in the blocked catchment. The DOC concentration record in blocked drains at this larger scale however indicated a reduction relative to the unblocked catchment. This reduction points to a change in flow pathways post blocking as highly coloured water re-navigates its way downstream. References: Gibson H, Worrall F, Burt TP, Adamson JK (2009) DOC budgets of drained peat catchments: implications for DOC production in peat soils, Hydrological Processes 23(13) 1901-1911 Limpens J (2008) Peatlands and the carbon cycle: from local processes to global implications- a synthesis, Biogeosciences 5 1475-1491

  19. Microbial phototrophic fixation of atmospheric CO2 in China subtropical upland and paddy soils

    NASA Astrophysics Data System (ADS)

    Ge, Tida; Wu, Xiaohong; Chen, Xiaojuan; Yuan, Hongzhao; Zou, Ziying; Li, Baozhen; Zhou, Ping; Liu, Shoulong; Tong, Chengli; Brookes, Phil; Wu, Jinshui

    2013-07-01

    Autotrophic microorganisms, which can fix atmospheric CO2 to synthesize organic carbon, are numerous and widespread in soils. However, the extent and the mechanism of CO2 fixation in soils remain poorly understood. We incubated five upland and five paddy soils from subtropical China in an enclosed, continuously 14CO2-labeled, atmosphere and measured 14CO2 incorporated into soil organic matter (SOC14) and microbial biomass (MBC14) after 110 days. The five upland soils supported dominant crops soils (maize, wheat, sweet potato, and rapeseed) in the region, while all paddy soils were cultivated in a regime consisting of permanently-flooded double-cropping rice cultivation. The upland and paddy soils represented typical soil types (fluvisols and ultisols) and three landforms (upland, hill, and low mountain), ranging in total carbon from low (<10 g kg-1 soil organic carbon) to medium (10-20 g kg-1) to high (>20 g kg-1). Substantial amounts of 14CO2 were fixed into SOC14 (mean 20.1 7.1 mg C kg-1 in upland soil, 121.1 6.4 mg C kg-1 in paddy soil) in illuminated soils (12 h light/12 h dark), whereas no 14C was fixed in soils incubated in continuous darkness. We concluded that the microbial CO2 fixation was almost entirely phototrophic rather than chemotrophic. The rate of SOC14 synthesis was significantly higher in paddy soils than in upland soils. The SOC14 comprised means of 0.15 0.01% (upland) and 0.65 0.03% (paddy) of SOC. The extent of 14C immobilized as MBC14 and that present as dissolved organic C (DOC14) differed between soil types, accounting for 15.69-38.76% and 5.54-18.37% in upland soils and 15.57-40.03% and 3.67-7.17% of SOC14 in paddy soils, respectively. The MBC14/MBC and DOC14/DOC were 1.76-5.70% and 1.69-5.17% in the upland soils and 4.23-28.73% and 5.65-14.30% in the paddy soils, respectively. Thus, the newly-incorporated C stimulated the dynamics of DOC and MBC more than the dynamics of SOC. The SOC14 and MBC14 concentrations were highly significantly correlated (r = 0.946; P < 0.0001). We conclude that CO2 uptake by phototrophic soil microorganisms can contribute significantly to carbon assimilation in soil, and so warrants further future study.

  20. Field portable XRF as a tool for the assessment of contaminated peat soils

    NASA Astrophysics Data System (ADS)

    Shuttleworth, Emma; Evans, Martin; Rothwell, James; Hutchinson, Simon

    2013-04-01

    Upland blanket bogs in the UK have suffered severe erosion over the last millennium but there is evidence to show that this has increased in intensity in the last 250 years, coinciding with increased pressures on the land during the British Industrial Revolution. Upland peat soils in close proximity to urban and industrial areas can be contaminated with - and act as sinks for - high concentrations of atmospherically deposited lead. Atmospheric pollution has been shown to have had significant effects on blanket bog vegetation, the damage and removal of which makes the peat mass highly susceptible to erosion. Erosion of these soils has the potential to release lead into the fluvial system. Detailed quantification of lead concentrations across the surface of actively eroding peatlands is vital in order to understand lead storage and release in such environments. Previous attempts to quantify peatland lead pollution have been undertaken using the inventory approach. However, there can be significant within-site spatial heterogeneity in lead concentrations, highlighting the need for multiple samples to properly quantify lead storage. Lead concentrations in peat are traditionally derived through acid extraction followed by ICP-OES or AAS analyses, but these can be time consuming, expensive and destructive. By contrast, field portable x-ray fluorescence (FPXRF) analysers are relatively inexpensive, allow a large number of samples to be processed in a comparatively short time, giving a high level of detail with little disturbance to the surrounding area. FPXRF continues to gain acceptance in the study of metal contaminated soil but has not been used to conduct field surveys of contaminated peat soils due to their high moisture content. This study compares lead concentration data obtained in situ using a handheld Niton XL3t 900 XRF analyser with data derived from ex situ lab based analyses. In situ measurements were acquired across degraded and intact peatland sites in the Peak District, UK. Field samples were then dried, homogenised and analysed again using the FPXRF before subsequent acid digestion and analysis using ICP-OES. The moisture content of the samples was also determined and used to normalise the in situ field measurements. Good relationships were found between in situ and ex situ lead concentration data. When comparing in situ and ex situ derived FPXRF concentrations, linear regression analysis yielded R2 values of 0.86. This was improved significantly when in situ concentrations are normalised for moisture content (R2 = 0.92). A similar relationship was found between moisture corrected in situ results and ICP-OES derived values. These is also and excellent relationship between ex situ FPXRF and ICP-OES data (R2 = 0.99). This study reveals that FPXRF can provide an accurate, rapid and cost-effective means of assessing lead content in contaminated peat. The FPXRF analyser can be used to produce high quality data both in situ and ex situ, and shows promise as a tool for use in sediment source fingerprinting and understanding sediment dynamics in wet, organic systems.

  1. Peat soil composition as indicator of plants growth environment

    NASA Astrophysics Data System (ADS)

    Noormets, M.; Tonutare, T.; Kauer, K.; Szajdak, L.; Kolli, R.

    2009-04-01

    Exhausted milled peat areas have been left behind as a result of decades-lasting intensive peat production in Estonia and Europe. According to different data there in Estonia is 10 000 - 15 000 ha of exhausted milled peat areas that should be vegetated. Restoration using Sphagnum species is most advantageous, as it creates ecological conditions closest to the natural succession towards a natural bog area. It is also thought that the large scale translocation of vegetation from intact bogs, as used in some Canadian restoration trials, is not applicable in most of European sites due to limited availability of suitable donor areas. Another possibility to reduce the CO2 emission in these areas is their use for cultivation of species that requires minimum agrotechnical measures exploitation. It is found by experiments that it is possible to establish on Vaccinium species for revegetation of exhausted milled peat areas. Several physiological activity of the plant is regulated by the number of phytohormones. These substances in low quantities move within the plant from a site of production to a site of action. Phytohormone, indole-3-acetic acid (IAA) is formed in soils from tryptophane by enzymatic conversion. This compound seems to play an important function in nature as result to its influence in regulation of plant growth and development. A principal feature of IAA is its ability to affect growth, development and health of plants. This compound activates root morphology and metabolic changes in the host plant. The physiological impact of this substance is involved in cell elongation, apical dominance, root initiation, parthenocarpy, abscission, callus formation and the respiration. The investigation areas are located in the county of Tartu (58˚ 22' N, 26˚ 43' E), in the southern part of Estonia. The soil of the experimental fields belongs according to the WRB soil classification, to the soils subgroups of Fibri-Dystric Histosols. The investigation areas were chosen by following criteria: (1) plantcover age; (2) cultivated plant species; (3) utilized agrotechnology; (4) comparisons between different factors were created by using natural growth areas of Vaccinaceae (natural bog area, Vaccinaceae growth area on mineral soil). For the investigation is important to choose areas with different age of plant covers, because according to plants age the surface of exhausted peat land will be covered in relation to the width of plants. The purpose of current article is to investigate the biological and chemical parameters co-influences in peat soil. Thus, the major interest is on the plant growth hormone indole-3-acetic acid distribution and dynamics in peat soil and dependence of plant cover, also its influence to the plants growth. Moreover, its contribution to yield and new growth area invasion will be discussed.

  2. Peat

    USGS Publications Warehouse

    Apodaca, L.E.

    2011-01-01

    In 2010, domestic production of peat, excluding Alaska, was estimated to be 612 kt (674,600 st), compared with 609 kt (671,300 st) in 2009. In 2010, imports increased to 947 kt (1.04 million st), compared with 906 kt (998,600 st) in 2009. Exports were estimated to have decreased to 69 kt (76,000 st) in 2010. U.S. apparent consumption for 2010 was estimated to have increased to 1.5 Mt (1.65 million st). World production was estimated to be about 23 Mt (25 million st) in 2010, which is 8 percent lower than in 2009.

  3. Peat

    USGS Publications Warehouse

    Apodaca, L.E.

    2012-01-01

    In 2011, domestic production of peat, excluding Alaska, was estimated to be 605 kt (667,000 st), compared with 628 kt (629,000 st) in 2010. In 2011, imports increased to 1.1. Mt (1.2 million st) compared with 947 kt (1 million st) in 2010, and exports were estimated to have decreased to 39 kt (43,000 st) in 2011. U.S. apparent consumption for 2011 was estimated to have increased to 1.6 Mt (1.7 million st). World production was estimated to be about 22 Mt (24 million st) in 2011, which was 6 percent lower than 2010.

  4. Peat

    USGS Publications Warehouse

    Apodaca, L.E.

    2010-01-01

    In 2009, domestic production of peat, excluding Alaska, was estimated to be 610 kt (672,000 st), compared with 615 kt (678,000 st) in 2008. In 2009, imports decreased to 906 kt (999,000 st) compared with 936 kt (1 million st) in 2008, and exports were estimated to have increased to 77 kt (85,000 st) in 2009. U.S. apparent consumption for 2009 was estimated to be about the same as in 2008. World production was estimated to be about 25 Mt (27.5 million st) in 2009, which is about the same as 2008.

  5. Peat

    USGS Publications Warehouse

    Apodaca, L.E.

    2013-01-01

    In 2012, domestic production of peat, excluding Alaska, was estimated to be 560 kt (617,000 st), compared with 568 kt (626,000 st) in 2011. In 2012, imports decreased to 940 kt (1 million st) compared with 982 kt (1.1 million st) in 2011, and exports were estimated to have increased to 75 kt (82,600 st) in 2012. U.S. apparent consumption for 2012 was estimated to have remained the same as that of 2011. World production was estimated to be about 27 Mt (30 million st) in 2012, which was slightly higher than 2011.

  6. Soil physicochemical and biological properties of paddy-upland rotation: a review.

    PubMed

    Zhou, Wei; Lv, Teng-Fei; Chen, Yong; Westby, Anthony P; Ren, Wan-Jun

    2014-01-01

    Paddy-upland rotation is an unavoidable cropping system for Asia to meet the increasing demand for food. The reduction in grain yields has increased the research interest on the soil properties of rice-based cropping systems. Paddy-upland rotation fields are unique from other wetland or upland soils, because they are associated with frequent cycling between wetting and drying under anaerobic and aerobic conditions; such rotations affect the soil C and N cycles, make the chemical speciation and biological effectiveness of soil nutrient elements varied with seasons, increase the diversity of soil organisms, and make the soil physical properties more difficult to analyze. Consequently, maintaining or improving soil quality at a desirable level has become a complicated issue. Therefore, fully understanding the soil characteristics of paddy-upland rotation is necessary for the sustainable development of the system. In this paper, we offer helpful insight into the effect of rice-upland combinations on the soil chemical, physical, and biological properties, which could provide guidance for reasonable cultivation management measures and contribute to the improvement of soil quality and crop yield. PMID:24995366

  7. Soil Physicochemical and Biological Properties of Paddy-Upland Rotation: A Review

    PubMed Central

    Lv, Teng-Fei; Chen, Yong; Westby, Anthony P.; Ren, Wan-Jun

    2014-01-01

    Paddy-upland rotation is an unavoidable cropping system for Asia to meet the increasing demand for food. The reduction in grain yields has increased the research interest on the soil properties of rice-based cropping systems. Paddy-upland rotation fields are unique from other wetland or upland soils, because they are associated with frequent cycling between wetting and drying under anaerobic and aerobic conditions; such rotations affect the soil C and N cycles, make the chemical speciation and biological effectiveness of soil nutrient elements varied with seasons, increase the diversity of soil organisms, and make the soil physical properties more difficult to analyze. Consequently, maintaining or improving soil quality at a desirable level has become a complicated issue. Therefore, fully understanding the soil characteristics of paddy-upland rotation is necessary for the sustainable development of the system. In this paper, we offer helpful insight into the effect of rice-upland combinations on the soil chemical, physical, and biological properties, which could provide guidance for reasonable cultivation management measures and contribute to the improvement of soil quality and crop yield. PMID:24995366

  8. Can carbon offsetting pay for upland ecological restoration?

    NASA Astrophysics Data System (ADS)

    Worrall, F.

    2012-04-01

    Upland peat soils represent a large terrestrial carbon store and as such have the potential to be either an ongoing net sink of carbon or a significant net source of carbon. In the UK many upland peats are managed for a range of purposes but these purposes have rarely included carbon stewardship. However, there is now an opportunity to consider whether management practices could be altered to enhance storage of carbon in upland peats. Further, there are now voluntary and regulated carbon trading schemes operational throughout Europe that mean stored carbon, if verified, could have an economic and tradeable value. This means that new income streams could become available for upland management. The 'Sustainable Uplands' RELU project has developed a model for calculating carbon fluxes from peat soils that covers all carbon uptake and release pathways (e.g. fluvial and gaseous pathways). The model has been developed so that the impact of common management options within UK upland peats can be considered. The model was run for a decade from 1997-2006 and applied to an area of 550 km2 of upland peat soils in the Peak District. The study estimates that the region is presently a net sink of -62 Ktonnes CO2 equivalent at an average export of -136 tonnes CO2 equivalent/km2/yr.. If management interventions were targeted across the area the total sink could increase to -160 Ktonnes CO2/yr at an average export of -219 tonnes CO2 equivalent/km2/yr. However, not all interventions resulted in a benefit; some resulted in increased losses of CO2 equivalents. Given present costs of peatland restoration and value of carbon offsets, the study suggests that 51% of those areas, where a carbon benefit was estimated by modelling for targeted action of management interventions, would show a profit from carbon offsetting within 30 years. However, this percentage is very dependent upon the price of carbon used.

  9. Soil hydraulic properties of sphagnum moss and peat

    NASA Astrophysics Data System (ADS)

    Weber, Tobias K. D.; Iden, Sascha C.; Scharnagl, Benedikt; Durner, Wolfgang

    2015-04-01

    The moisture state of the vadose zone (acrotelm) of ombrotrophic peatlands decisively determines whether carbon is contained in soil organic matter or released to the atmosphere. As the pore space is variably saturated with water throughout the year, oxygen diffusion, heat, and solute transport and thus the redox state are a function of water content over time. For prediction purposes, the hydrological processes must be epitomised in computer models which establish a link between the terrestrial water cycle and the carbon cycle. This requires a proper representation of effective soil hydraulic properties which are a mandatory input to the Richards equation, the standard model for variably-saturated flow processes in porous media. By applying the Richards equation to peatlands, one assumes that the acrotelm can be conceptualised as a rigid porous material. To test this approximation and select the most adequate set of soil hydraulic property functions, we conducted a series of specifically designed laboratory evaporation experiments on sphagnum moss and decomposed sphagnum peat. Sampling was carried out in five centimeter depth increments of an ombrotrophic bog profile in the Harz mountains. We selected sphagnum moss as it is a predominant plant species colonising bogs of the Boreal. Inverse modelling was used to test the adequacy of different parameterizations of soil hydraulic property functions. We used pressure head data measured by two tensiometers in the objective function to identify soil hydraulic properties. The Richards equation was used as process model. We critically assess the applicability of the van Genuchten/Mualem model, which finds frequent application in peatland hydrology, and discuss alternatives which account for (1) multimodal pore size distributions, (2) physical plausibility towards the dry end, (3) capillary and non-capillary storage and flow, and (4) isothermal flow of water vapour. Finally, our results indicate that applying the Richards equation to water flow under evaporation conditions to sphagnum moss and sphagnum peat is a feasible approximation.

  10. Effects of peat fires on the characteristics of humic acid extracted from peat soil in Central Kalimantan, Indonesia.

    PubMed

    Yustiawati; Kihara, Yusuke; Sazawa, Kazuto; Kuramitz, Hideki; Kurasaki, Masaaki; Saito, Takeshi; Hosokawa, Toshiyuki; Syawal, M Suhaemi; Wulandari, Linda; Hendri I; Tanaka, Shunitz

    2015-02-01

    When peat forest fires happen, it leads to burn soil and also humic acids as a dominant organic matter contained in peat soil as well as the forest. The structure and properties of humic acids vary depending on their origin and environment, therefore the transformation of humic acid is also diverse. The impacts of the peat fires on peat soil from Central Kalimantan, Indonesia were investigated through the characterization of humic acids, extracted from soil in burnt and unburnt sites. The characterization of humic acids was performed by elemental composition, functional groups, molecular weight by HPSEC, pyrolysate compounds by pyrolysis-GC/MS, fluorescence spectrum by 3DEEM spectrofluorometer, and thermogravimetry. The elemental composition of each humic substance indicated that the value of H/C and O/C of humic acids from burnt sites were lower than that from unburnt sites. The molecular weight of humic acids from burnt sites was also lower than that from unburnt sites. Pyrolysate compounds of humic acids from unburnt sites differed from those of humic acids from burnt soil. The heating experiment showed that burning process caused the significant change in the properties of humic acids such as increasing the aromaticity and decreasing the molecular weight. PMID:24781330

  11. Distribution of tetraether lipids in agricultural soils - differentiation between paddy and upland management

    NASA Astrophysics Data System (ADS)

    Mueller-Niggemann, C.; Utami, S. R.; Marxen, A.; Mangelsdorf, K.; Bauersachs, T.; Schwark, L.

    2015-10-01

    Insufficient knowledge of the composition and variation of isoprenoid and branched glycerol dialkyl glycerol tetraethers (GDGTs) in agricultural soils exists, despite of the potential effect of different management types (e.g. soil/water and redox conditions, cultivated plants) on GDGT distribution. Here, we determined the influence of different soil management types on the GDGT composition in paddy (flooded) and adjacent upland (non-flooded) soils, and if available also forest, bushland and marsh soils. To compare the local effects on GDGT distribution patterns, we collected comparable soil samples in various locations from tropical (Indonesia, Vietnam and Philippines) and subtropical (China and Italy) sites. We found that differences in the distribution of isoprenoid GDGTs (iGDGTs) as well as of branched GDGTs (brGDGTs) are predominantly controlled by management type and only secondarily by climatic exposition. In general upland soil had higher crenarchaeol contents than paddy soil, which on the contrary was more enriched in GDGT-0. The GDGT-0 / crenarchaeol ratio was 3-27 times higher in paddy soil and indicates the enhanced presence of methanogenic archaea, which were additionally linked to the number of rice cultivation cycles per year (higher number of cycles was coupled with an increase in the ratio). The TEX86 values were 1.3 times higher in upland, bushland and forest soils than in paddy soils. In all soils brGDGT predominated over iGDGTs, with the relative abundance of brGDGTs increasing from subtropical to tropical soils. Higher BIT values in paddy soils compared to upland soils together with higher BIT values in soil from subtropical climates indicate effects on the amounts of brGDGT through differences in management as well as climatic zones. In acidic soil CBT values correlated well with soil pH. In neutral to alkaline soils, however, no apparent correlation but an offset between paddy and upland managed soils was detected, which may suggest that soil moisture may exert an additional control on the CBT in these soils. Lower MBT' values and calculated temperatures (TMC) in paddy soils compared to upland soils may indicate a management (e.g. enhanced soil moisture through flooding practises) induced effect on mean annual soil temperature (MST).

  12. Effect of soil type and fertilizer management on archaeal community in upland field soils.

    PubMed

    Hoshino, Yuko Takada; Morimoto, Sho; Hayatsu, Masahito; Nagaoka, Kazunari; Suzuki, Chika; Karasawa, Toshihiko; Takenaka, Makoto; Akiyama, Hiroko

    2011-01-01

    The effects of soil and fertilizer types on archaeal communities were evaluated by real-time PCR and PCR-denaturing gradient gel electrophoresis (DGGE) targeting the 16S rRNA gene of total DNA directly extracted from upland field soils. Twelve experimental upland field plots containing four different soil types, i.e., Cumulic Andosol, Low-humic Andosol, Yellow Soil and Gray Lowland Soil, were maintained under three different fertilizer management systems for 8 years (chemical fertilizer, rice husks and cow manure, and pig manure, respectively). Two-way ANOVA and RDA analyses showed that the copy number and PCR-DGGE profile of archaeal 16S rRNA gene were affected mainly by soil type, especially between Andosol and non-Andosol, but were also influenced by fertilizer type. Among several soil chemical properties, total N content showed a significant correlation to archaeal community. Sequence analyses showed that most of the major DGGE bands corresponded to uncultured Crenarchaeota of Group I.1b that contained ammonia-oxidizing archaea (AOA). These sequences were separated into two clusters in the phylogenetic tree and each lineage showed a different response to total N content. PMID:21670564

  13. Effect of Soil Stratification on the Development and Migration of Headcuts in Upland Concentrated Flows

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Experiments were conducted to examine the effect of vertical stratification in soil erodibility on the development and migration of steady-state headcut scour holes in upland concentrated flows typical of agricultural fields. Packed soil beds with a pre-formed step were subjected to identical simul...

  14. Soil erosion predictions from upland areas – a discussion of selected RUSLE2 advances and needs

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Obtaining more accurate soil loss estimates from upland areas is important for improving management practices on agricultural fields. Much of the soil erosion prediction research of the last 25 years has been concerned with this goal. The most widely used predictive relationships have been the Unive...

  15. Morphodynamics of headcut development and soil erosion in upland concentrated flows

    Technology Transfer Automated Retrieval System (TEKTRAN)

    In agricultural regions, gully erosion is now recognized as becoming a dominant source of soil loss, and the development and upstream migration of headcuts is critical to the initiation, incision, and dissection of these upland areas. The present investigation sought to examine the effect of soil t...

  16. Organic matter composition of peat soils affected by genesis and drainage conditions

    NASA Astrophysics Data System (ADS)

    Ellerbrock, Ruth H.; Gerke, Horst H.; Heller, Christian; Leue, Martin

    2015-04-01

    The organic matter (OM) of peat soils often dominates the overall soil properties because of the low mineral contents. The quantity and quality of OM depends on the environmental conditions during peat genesis. We hypothesize that the OM quality in terms of the composition of OM functional groups can help to better understand the processes of peat soil development. The objective was to analyze OM composition of peat soils as a function of genesis, water regime, and land use. Three plant samples and 29 peat samples were taken from 7 sites (located northern Germany) which are different in peat genesis and land use intensity. The samples were analyzed with Fourier Transform infrared (FTIR) spectroscopy. The lower contents in CH functional groups for the fen samples as compared to bog samples reflect a higher biochemical activity in the fen as compared to the ombothrophic bog environments. The role of the peat genesis for OM composition could be confirmed by FTIR data of a Canadian ombrotrophic bog. The relative higher CH content in samples from non-drained as compared to those from drained fens could be explained by selective preservation due to anaerobic conditions. Increasing drainage intensity seems to cause a relative decrease in CH content and an increase in C=O content of the peat samples, reflecting an enhanced aerobic decomposition. The results suggest that peat genesis and drainage affects both OM content and composition substantially. However, the greater variability in OM composition as compared to that of bog samples indicate that SOM in peat soils is not only influenced by climate, land use or drainage but it is also affected by the type of land use at sites in the close neighborhood.

  17. Analysing flow patterns in degraded peat soils using TiO2 dye

    NASA Astrophysics Data System (ADS)

    Liu, Haojie; Lennartz, Bernd

    2014-05-01

    Dye tracing is a valuable method for studying the flow patterns in soils. However, limited information is available on water flow and solute transport pathways in dark colored peat soils because the frequently used Brilliant Blue FCF dye does not visibly stain the soil. In this study, we were aiming at testing the suitability of Titanium dioxide (TiO2) as a dye tracer for dark peat soils. The objectives were to quantify the physical properties of different degraded peat soils and visualize the flow patterns. Soil samples were collected from two low-lying fen sites, where the top soil was highly degraded, while lower horizons were less decomposed. Dye tracer experiments were conducted at both sites by applying a TiO2 suspension (10 g/l) with a pulse of 40 mm. Soil profiles were prepared for photo documentation the following day. It was found that the physical and hydraulic properties of peat were significantly influenced by the degree of peat decomposition and degradation. Higher decomposed and degraded peat soils had a higher bulk density, lower organic matter content and lower porosity. Moreover, higher decomposition and degradation resulted in a lower saturated hydraulic conductivity as long as investigated samples originated from the same site. In addition, degraded peat soils showed less anisotropy than un-degraded peat. It turned out that TiO2 is a suitable dye tracer to visualize the flow paths in peat soils. Although dye patterns differed within the same plot and between different plots, most of the flow patterns indicated a preferential flow situation. The distribution of TiO2 in the soil profile, as analyzed from 5 by 5 cm grid cells, compared to the distribution of bromide, which was applied along with the dye confirming the suitability of the dye tracer. Un-decomposed plant structures, such as wood branches and leaves, were identified as the major preferential flow path in un-degraded peat. For degraded peat, bio-pores, such as root and earthworm channels operated as the major transport domain.

  18. Macronutrient concentration in plant parts of cotton fertilized with broiler Litter in a marginal upland Soil

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Effectiveness of surface-applied unincorporated litter relative to conventional inorganic fertilizers under no-till or conventional-till cotton (Gossypium hirsutum L.) production systems and the magnitude of litter benefit reduction associated with lack of incorporation in the upland soils of the so...

  19. Nutrient dynamics from broiler litter applied to no-till cotton in an upland soil

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Surface-applying broiler litter to a no-till cotton field increases the potential for loss of manure nutrients from the fields in runoff events and volitization of the NH4-N. An experiment was conducted on an upland Atwood silt loam soil (fine-silty, mixed, thermic Typic Paleududalfs) at the Pontoto...

  20. Saprophytic and Potentially Pathogenic Fusarium Species from Peat Soil in Perak and Pahang

    PubMed Central

    Karim, Nurul Farah Abdul; Mohd, Masratulhawa; Nor, Nik Mohd Izham Mohd; Zakaria, Latiffah

    2016-01-01

    Isolates of Fusarium were discovered in peat soil samples collected from peat swamp forest, waterlogged peat soil, and peat soil from oil palm plantations. Morphological characteristics were used to tentatively identify the isolates, and species confirmation was based on the sequence of translation elongation factor-1α (TEF-1α) and phylogenetic analysis. Based on the closest match of Basic Local Alignment Search Tool (BLAST) searches against the GenBank and Fusarium-ID databases, five Fusarium species were identified, namely F. oxysporum (60%), F. solani (23%), F. proliferatum (14%), F. semitectum (1%), and F. verticillioides (1%). From a neighbour-joining tree of combined TEF-1α and β-tubulin sequences, isolates from the same species were clustered in the same clade, though intraspecies variations were observed from the phylogenetic analysis. The Fusarium species isolated in the present study are soil inhabitants and are widely distributed worldwide. These species can act as saprophytes and decomposers as well as plant pathogens. The presence of Fusarium species in peat soils suggested that peat soils could be a reservoir of plant pathogens, as well-known plant pathogenic species such F. oxysporum, F. solani, F. proliferatum, and F. verticillioides were identified. The results of the present study provide knowledge on the survival and distribution of Fusarium species.

  1. Thermomagnetic properties of peat-soil layers from Sag pond near Lembang Fault, West Java, Indonesia

    NASA Astrophysics Data System (ADS)

    Iryanti, Mimin; Wibowo, Dimas Maulana; Bijaksana, Satria

    2015-09-01

    Sag pond is a body of water near fault system as water flows blocked by the fault. Sag pond is a special type of environment for peat formation as peat layers in were deposited as the fault moves in episodic fashion. Depending on the history of the fault, peat layers are often interrupted by soil layers. In this study, core of peat-soil layers from a Sag pond in Karyawangi Village near Lembang Fault was obtained and analyzed for its magnetic properties. The 5 m core was obtained using a hand auger. Individual samples were obtained every cm and measured for their magnetic susceptibility. In general, there are three distinct magnetic susceptibility layers that were associated with peat and soil layers. The upper first 1 m is unconsolidated mud layer with its relatively high magnetic susceptibility. Between 1-2.81 m, there is consolidated mud layer and the lowest part (2.82-5) m is basically peat layer. Six samples were then measured for their thermomagnetic properties by measuring their susceptibility during heating and cooling from room temperature to 700°C. The thermomagnetic profiles provide Curie temperatures for various magnetic minerals in the cores. It was found that the upper part (unconsolidated mud) contains predominantly iron-oxides, such as magnetite while the lowest part (peat layer) contains significant amount of iron-sulphides, presumably greigite.

  2. Micromonospora humi sp. nov., isolated from peat swamp forest soil.

    PubMed

    Songsumanus, Apakorn; Tanasupawat, Somboon; Thawai, Chitti; Suwanborirux, Khanit; Kudo, Takuji

    2011-05-01

    A novel actinomycete, strain P0402(T), was isolated from peat swamp forest soil collected in Thailand. Its taxonomic position was determined by using a polyphasic taxonomic approach. The chemotaxonomic characteristics of this strain matched those of the genus Micromonospora, i.e. the presence of meso-diaminopimelic acid and N-glycolyl muramic acid in the peptidoglycan, whole-cell sugar pattern D, phospholipid type II, and cellular fatty acid type 3b. Phylogenetic analysis based on 16S rRNA gene sequences revealed a close relationship between strain P0402(T) and Micromonospora coxensis JCM 13248(T) (99.0 % similarity), Micromonospora eburnea JCM 12345(T) (99.0 %), Micromonospora marina JCM 12870(T) (98.9 %), Micromonospora halophytica JCM 3125(T) (98.7 %), Micromonospora chalcea JCM 3031(T) (98.7 %), Micromonospora purpureochromogenes JCM 3156(T) (98.6 %) and Micromonospora aurantiaca JCM 10878(T) (98.5 %). It could be clearly distinguished from these type strains based on low levels of DNA-DNA relatedness and phenotypic differences. On the basis of the data presented, strain P0402(T) is suggested to represent a novel species of the genus Micromonospora, for which the name Micromonospora humi sp. nov. is proposed. The type strain is P0402(T) (?=?JCM 15292(T) ?=?PCU 315(T) ?=?TISTR 1883(T)). PMID:20562246

  3. Polyphenols as enzyme inhibitors in different degraded peat soils: Implication for microbial metabolism in rewetted peatlands

    NASA Astrophysics Data System (ADS)

    Zak, Dominik; Roth, Cyril; Gelbrecht, Jörg; Fenner, Nathalie; Reuter, Hendrik

    2015-04-01

    Recently, more than 30,000 ha of drained minerotrophic peatlands (= fens) in NE Germany were rewetted to restore their ecological functions. Due to an extended drainage history, a re-establishment of their original state is not expected in the short-term. Elevated concentrations of dissolved organic carbon, ammonium and phosphate have been measured in the soil porewater of the upper degraded peat layers of rewetted fens at levels of one to three orders higher than the values in pristine systems; an indicator of increased microbial activity in the upper degraded soil layers. On the other hand there is evidence that the substrate availability within the degraded peat layer is lowered since the organic matter has formerly been subject to intense decomposition over the decades of drainage and intense agricultural use of the areas. Previously however, it was suggested that inhibition of hydrolytic enzymes by polyphenolic substances is suspended during aeration of peat soils mainly due to the decomposition of the inhibiting polyphenols by oxidising enzymes such as phenol oxidase. Accordingly we hypothesised a lack of enzyme inhibiting polyphenols in degraded peat soils of rewetted fens compared to less decomposed peat of more natural fens. We collected both peat samples at the soil surface (0-20 cm) and fresh roots of dominating vascular plants and mosses (as peat parent material) from five formerly drained rewetted sites and five more natural sites of NE Germany and NW Poland. Less decomposed peat and living roots were used to obtain an internal standard for polyphenol analysis and to run enzyme inhibition tests. For all samples we determined the total phenolic contents and in addition we distinguished between the contents of hydrolysable and condensed tannic substances. From a methodical perspective the advantage of internal standards compared to the commercially available standards cyanidin chloride and tannic acid became apparent. Quantification with cyanidin or tannic acid led to a considerable underestimation (up to 90%) of polyphenolic concentrations in peat soils. As hypothesised we found that highly degraded peat contains far lower levels of total polyphenolics (factor 8) and condensed tannins (factor 50) than less decomposed peat. In addition we detected large differences between different plant species with highest polyphenolic contents for the roots of Carex appropinquata that were more than 10-fold higher than Sphagnum spp. (450 mg/g dry mass vs. 39 mg/g dry mass). Despite these differences, we did not find a significant correlation between enzyme activities and peat degradation state, indicating that there is no simple linear relationship between polyphenolic contents and microbial activity.

  4. Permafrost collapse alters soil carbon stocks, respiration, CH4 , and N2O in upland tundra.

    PubMed

    Abbott, Benjamin W; Jones, Jeremy B

    2015-12-01

    Release of greenhouse gases from thawing permafrost is potentially the largest terrestrial feedback to climate change and one of the most likely to occur; however, estimates of its strength vary by a factor of thirty. Some of this uncertainty stems from abrupt thaw processes known as thermokarst (permafrost collapse due to ground ice melt), which alter controls on carbon and nitrogen cycling and expose organic matter from meters below the surface. Thermokarst may affect 20-50% of tundra uplands by the end of the century; however, little is known about the effect of different thermokarst morphologies on carbon and nitrogen release. We measured soil organic matter displacement, ecosystem respiration, and soil gas concentrations at 26 upland thermokarst features on the North Slope of Alaska. Features included the three most common upland thermokarst morphologies: active-layer detachment slides, thermo-erosion gullies, and retrogressive thaw slumps. We found that thermokarst morphology interacted with landscape parameters to determine both the initial displacement of organic matter and subsequent carbon and nitrogen cycling. The large proportion of ecosystem carbon exported off-site by slumps and slides resulted in decreased ecosystem respiration postfailure, while gullies removed a smaller portion of ecosystem carbon but strongly increased respiration and N2 O concentration. Elevated N2 O in gully soils persisted through most of the growing season, indicating sustained nitrification and denitrification in disturbed soils, representing a potential noncarbon permafrost climate feedback. While upland thermokarst formation did not substantially alter redox conditions within features, it redistributed organic matter into both oxic and anoxic environments. Across morphologies, residual organic matter cover, and predisturbance respiration explained 83% of the variation in respiration response. Consistent differences between upland thermokarst types may contribute to the incorporation of this nonlinear process into projections of carbon and nitrogen release from degrading permafrost. PMID:26301544

  5. Seasonal influences on fungal community structure in unimprovedand improved upland grassland soils

    SciTech Connect

    Kennedy, Nabla; Brodie, Eoin; Connolly, John; Clipson, Nicholas

    2006-07-01

    Seasonal and management influences on the fungal communitystructure of two upland grassland soils were investigated. An upland sitecontaining both unimproved, floristically-diverse (U4a) and mesotrophic,improved (MG7b) grassland types was selected, and samples from bothgrassland types were taken at five times in one year. Soil fungalcommunity structure was assessed using fungal automated ribosomalintergenic spacer analysis (ARISA), a DNA-profiling approach. Grasslandmanagement regime was found to strongly affect fungal communitystructure, with fungal ARISA profiles from unimproved and improvedgrassland soils differing significantly. The number of fungal ribotypesfound was higher in unimproved than improved grassland soils, providingevidence that improvement may reduce the suitability of upland soil as ahabitat for specific groups of fungi. Seasonal influences on fungalcommunity structure were also noted, with samples taken in autumn(October) more correlated with change in ribotype profiles than samplesfrom otherseasons. However, seasonal variation did not obscure themeasurement of differences in fungal community structure that were due toagricultural improvement, with canonical correspondence analysis (CCA)indicating grassland type had a stronger influence on fungal profilesthan season.

  6. Patterns in Stream Respiration and Primary Production Along a Gradient of Upland Soil and Vegetation Disturbance

    NASA Astrophysics Data System (ADS)

    Houser, J. N.; Mulholland, P. J.; Maloney, K.

    2002-12-01

    Because watershed characteristics determine the inputs of sediments and nutrients to streams, natural or anthropogenic disturbance of upland soil and vegetation can affect in-stream processes. Ft. Benning (Columbus, GA) exhibits a wide range of upland disturbance intensity due to spatial variability in the intensity of military training (infantry and tank maneuvers). The uplands of some stream catchments are highly disturbed while others remain relatively undisturbed. We used this disturbance gradient to test the hypothesis that upland soil and vegetation disturbance reduces in-stream respiration and gross primary production (GPP). We selected 11 stream reaches located in 11 different catchments along a gradient of disturbance intensity. Highly disturbed catchments were found to export substantial inorganic sediments to their streams. As a result, larger increases in inorganic suspended sediment concentrations occurred during storm events in the highly disturbed sites than in the low disturbance sites. This increased input of inorganic suspended sediments reduced benthic percent organic matter in the highly disturbed stream reaches. Associated with this reduced organic matter content were reduced rates of in-stream respiration in highly disturbed stream reaches during summer and spring, but not during fall and winter. GPP was found to be lower in highly disturbed stream reaches only during the spring (no significant pattern was observed in the other seasons). These results add to our growing understanding of the important connections between watershed disturbance and in-stream processes.

  7. Controls on soil solution nitrogen along an altitudinal gradient in the Scottish uplands.

    PubMed

    Jackson-Blake, L; Helliwell, R C; Britton, A J; Gibbs, S; Coull, M C; Dawson, L

    2012-08-01

    Nitrogen (N) deposition continues to threaten upland ecosystems, contributing to acidification, eutrophication and biodiversity loss. We present results from a monitoring study aimed at investigating the fate of this deposited N within a pristine catchment in the Cairngorm Mountains (Scotland). Six sites were established along an elevation gradient (486-908 m) spanning the key habitats of temperate maritime uplands. Bulk deposition chemistry, soil carbon content, soil solution chemistry, soil temperature and soil moisture content were monitored over a 5 year period. Results were used to assess spatial variability in soil solution N and to investigate the factors and processes driving this variability. Highest soil solution inorganic N concentrations were found in the alpine soils at the top of the hillslope. Soil carbon stock, soil solution dissolved organic carbon (DOC) and factors representing site hydrology were the best predictors of NO(3)(-) concentration, with highest concentrations at low productivity sites with low DOC and freely-draining soils. These factors act as proxies for changing net biological uptake and soil/water contact time, and therefore support the hypothesis that spatial variations in soil solution NO(3)(-) are controlled by habitat N retention capacity. Soil percent carbon was a better predictor of soil solution inorganic N concentration than mass of soil carbon. NH(4)(+) was less affected by soil hydrology than NO(3)(-) and showed the effects of net mineralization inputs, particularly at Racomitrium heath and peaty sites. Soil solution dissolved organic N concentration was strongly related to both DOC and temperature, with a stronger temperature effect at more productive sites. Due to the spatial heterogeneity in N leaching potential, a fine-scale approach to assessing surface water vulnerability to N leaching is recommended over the broad scale, critical loads approach currently in use, particularly for sensitive areas. PMID:22673176

  8. Molecular characterization of fungal communities in non-tilled, cover-cropped upland rice field soils.

    PubMed

    Nishizawa, Tomoyasu; Zhaorigetu; Komatsuzaki, Masakazu; Sato, Yoshinori; Kaneko, Nobuhiro; Ohta, Hiroyuki

    2010-01-01

    This study aimed to characterize soil fungal communities in upland rice fields managed with tillage/non-tillage and winter cover-cropping (hairy vetch and cereal rye) practices, using PCR-based molecular methods. The study plots were maintained as upland fields for 5 years and the soils sampled in the second and fifth years were analyzed using T-RFLP (terminal restriction fragment length polymorphism) profiling and clone libraries with the internal transcribed spacer (ITS) region and domain 1 (D1) of the fungal large-subunit (fLSU) rRNA (D1(fLSU)) as the target DNA sequence. From the 2nd-year-sample, 372 cloned sequences of fungal ITS-D1(fLSU) were obtained and clustered into 80 nonredundant fungal OTUs (operational taxonomic units) in 4 fungal phyla. The T-RFLP profiling was performed with the 2nd- and 5th-year-samples and the major T-RFs (terminal restriction fragments) were identified using a theoretical fragment analysis of the ITS-D1(fLSU) clones. These molecular analyses showed that the fungal community was influenced more strongly by the cover-cropping than tillage practices. Moreover, the non-tilled, cover-cropped soil was characterized by a predominance of Cryptococcus sp. in the phylum Basidiomycota. We provided a genetic database of the fungal ITS-D1(fLSU)s in the differently managed soils of upland rice fields. PMID:21597240

  9. Heterogeneity of biogenic gas ebullition in subtropical peat soils is revealed using time-lapse cameras

    NASA Astrophysics Data System (ADS)

    Comas, Xavier; Wright, William

    2012-04-01

    We tested a set of biogenic gas traps combined with time-lapse cameras to investigate the heterogeneous nature of biogenic gas ebullition events in subtropical peat soils at both the laboratory and field scale. The main findings are: (1) ebullition events in peat soils are highly heterogeneous; (2) estimates of flux rate are directly influenced by temporal scale of measurement with rapid (i.e., hourly) releasing events exceeding daily averages by one order of magnitude; and (3) increases in atmospheric pressure result in gas release from shallow peat soils into the atmosphere (i.e., ebullition), as indicated by a positive linear relation between changes in biogenic gas content and changes in atmospheric pressure. These results suggest that biogenic gas releases from shallow subtropical peat soils are not constant with larger than average daily fluxes being potentially released within hours during periods of increased atmospheric pressure. Furthermore, this study also shows the potential of time-lapse cameras for autonomously assessing the temporal variation in biogenic gas flux to the atmosphere from peatlands, and questions what temporal scale of measurement should be appropriate to infer dynamics of biogenic gas release in peat soils.

  10. Soil erosion on upland areas by rainfall and overland flow

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Soil erosion in agricultural watersheds is a systemic problem that has plagued mankind ever since the practice of agriculture began some 9,000 years ago. It is a worldwide problem, the severity of which varies from location to location depending on weather, soil type, topography, cropping practices,...

  11. Spatial and vertical distribution of mercury in upland forest soils across the northeastern United States

    PubMed Central

    Richardson, Justin B.; Friedland, Andrew J; Engerbretson, Teresa R.; Kaste, James M.; Jackson, Brian P.

    2013-01-01

    Assessing current Hg pools in forest soils of the northeastern U.S. is important for monitoring changes in Hg cycling. The forest floor, upper and lower mineral horizons were sampled at 17 long-term upland forest sites across the northeastern U.S. in 2011. Forest floor Hg concentration was similar across the study region (274 ± 13 μg kg−1) while Hg amount at northern sites (39 ± 6 g ha−1) was significantly greater than at western sites (11 ± 4 g ha−1). Forest floor Hg was correlated with soil organic matter, soil pH, latitude and mean annual precipitation and these variables explained approximately 70% of the variability when multiple regressed. Mercury concentration and amount in the lower mineral soil was correlated with Fe, soil organic matter and latitude, corresponding with Bs horizons of Spodosols (Podzols). Our analysis shows the importance of regional and soil properties on Hg accumulation in forest soils. PMID:23911621

  12. Effect of paddy-upland rotation on methanogenic archaeal community structure in paddy field soil.

    PubMed

    Liu, Dongyan; Ishikawa, Hiroki; Nishida, Mizuhiko; Tsuchiya, Kazunari; Takahashi, Tomoki; Kimura, Makoto; Asakawa, Susumu

    2015-01-01

    Methanogenic archaea are strict anaerobes and demand highly reduced conditions to produce methane in paddy field soil. However, methanogenic archaea survive well under upland and aerated conditions in paddy fields and exhibit stable community. In the present study, methanogenic archaeal community was investigated in fields where paddy rice (Oryza sativa L.) under flooded conditions was rotated with soybean (Glycine max [L.] Merr.) under upland conditions at different rotation histories, by polymerase chain reaction (PCR)-denaturing gradient gel electrophoresis (DGGE) and real-time quantitative PCR methods targeting 16S rRNA and mcrA genes, respectively. Soil samples collected from the fields before flooding or seeding, during crop cultivation and after harvest of crops were analyzed. The abundance of the methanogenic archaeal populations decreased to about one-tenth in the rotational plots than in the consecutive paddy (control) plots. The composition of the methanogenic archaeal community also changed. Most members of the methanogenic archaea consisting of the orders Methanosarcinales, Methanocellales, Methanomicrobiales, and Methanobacteriales existed autochthonously in both the control and rotational plots, while some were strongly affected in the rotational plots, with fatal effect to some members belonging to the Methanosarcinales. This study revealed that the upland conversion for one or longer than 1 year in the rotational system affected the methanogenic archaeal community structure and was fatal to some members of methanogenic archaea in paddy field soil. PMID:25113614

  13. High Potential for Iron Reduction in Upland Soils from Diverse Terrestrial Ecosystems

    NASA Astrophysics Data System (ADS)

    Yang, W. H.; Liptzin, D.

    2014-12-01

    Changes in the redox state of iron (Fe) can be coupled to the biogeochemical cycling of carbon (C), nitrogen, and phosphorus. The importance of Fe in catalyzing redox-driven biogeochemical cycling has been underappreciated in terrestrial ecosystems because they are not typically thought of as anaerobic environments. However, upland soils can experience anaerobic conditions following rainfall events or in microsites of high biological oxygen consumption. Measurements of Fe reduction rates in soils are difficult to compare among studies from different ecosystems, so we used the same assay to quantify potential Fe reduction in soils from upland environments (annual grassland, drained peatland pasture, and a rainforest) that varied in poorly crystalline Fe and total C. We slurried the soils and incubated them in a glovebox with a dinitrogen headspace. To evaluate the role of C availability in potential Fe reduction, we added sodium acetate daily at rates up to 0.6 mg C/g soil/d. We measured methane (CH4) production, acid- extractable Fe(II), citrate-ascorbate extractable Fe oxides, and pH over 5 days to determine the timing and magnitude of Fe reduction. In relatively dry soils (< 20 % gravimetric soil moisture), Fe reduction began after one day of anaerobic incubation as slurries, but all of the soils demonstrated high Fe reduction potential. On day 3, Fe reduction rates for the 0.05 mg C/g soil/d treatment were 1535 ± 51 μg Fe(III) g-1 d-1 in the annual grassland soil, 1205 ± 42 μg Fe(III) g-1 d-1 in the drained peatland soil, and 826 ± 54 μg Fe(III) g-1 d-1 in the rainforest soil. This contrasts with the trend in poorly crystalline Fe oxide pools across the sites: 3.87 ± 0.06 μg Fe(III) g-1 in the annual grassland, 7.49 μg Fe(III) g-1 in the drained peatland, and 20.84 ± 0.19 μg Fe(III) g-1 in the rainforest soil. Across all sites, small C additions (< 0.05 mg C/g soil/day) increased Fe reduction rates while larger C additions decreased Fe reduction. Iron reduction rates typically decreased by day 5, associated with an increase in CH4 concentrations suggesting that potentially reducible Fe was depleted. Our results suggest that upland soils have the potential to exhibit high short-term rates of Fe reduction that may play a role in driving C oxidation and other soil biogeochemical cycles during periods of anaerobiosis.

  14. Soil quality assessment for peat-mineral mix cover soil used in oil sands reclamation.

    PubMed

    Ojekanmi, A A; Chang, S X

    2014-09-01

    A soil quality (SQ) assessment and rating framework that is quantitative, iterative, and adaptable, with justifiable weighting for quality scores, is required for evaluating site-specific SQ at land reclamation sites. Such a framework needs to identify the minimum dataset that reflects the current knowledge regarding relationships between SQ indicators and relevant measures of ecosystem performance. Our objective was to develop nonlinear scoring functions for assessing the impact on SQ of peat-mineral mix (PMM) used as a cover soil at land reclamation sites. Soil functional indicators affected by PMM were extracted from existing databases and correlated with soil organic carbon (SOC). Based on defined objectives for SQ assessment, indicators with significant correlation ( < 0.05) to SOC were selected, normalized, and fitted to sigmoid functions using nonlinear regression procedure to establish SQ functions (SQFs) that can analyze changes in field capacity, permanent wilting point, soil nitrogen, and cation exchange capacity of PMM using SOC as input parameter. Application of the SQFs to an independent dataset produced ratings with mean differences similar to the treatment effects of mixing three levels of peat and mineral soil. These results show that derived ratings and weighing factors using SOC reflect the relationship between PMM treatment and other SQ indicators. Applying the developed SQFs to a long-term soil monitoring dataset shows that an increase or decrease in SOC from 10 to 20 g kg causes a significant change in SQ. This identifies the need for further nutrient and moisture management of PMM to support long-term SQ development in land reclamation. PMID:25603242

  15. Controls on soil solution nitrogen along an altitudinal gradient in the Scottish uplands

    NASA Astrophysics Data System (ADS)

    Jackson-Blake, L.; Helliwell, R. C.; Britton, A. J.; Gibbs, S.; Coull, M. C.; Dawson, L.

    2012-04-01

    Nitrogen (N) deposition continues to threaten upland ecosystems, contributing to acidification, eutrophication and biodiversity loss. We present results from a monitoring study aimed at investigating the fate of this deposited N within a relatively pristine catchment in the Cairngorm Mountains (Scotland). Six sites were established along an elevation gradient (486 - 908 m) spanning the key habitats of temperate maritime uplands. Bulk deposition chemistry, soil carbon content, soil solution chemistry, soil temperature and soil moisture content were monitored over a 5 year period, making this the first study of its kind in a maritime Alpine environment. Results were used to assess spatial variability in soil solution N and to investigate the factors and processes driving this variability. Highest soil solution inorganic N concentrations were found in the alpine soils at the top of the hillslope. Soil carbon stock, dissolved organic carbon concentration and factors representing site hydrology were the best predictors of nitrate concentration. These factors act as proxies for changing net biological uptake and soil/water contact time, and support the hypothesis that spatial variations in soil solution nitrate are controlled by habitat N retention capacity. Soil percent carbon was a better predictor of soil solution N concentration than mass of carbon. Ammonium was less affected by soil hydrology than nitrate and showed the effects of net mineralization inputs, particularly at Racomitrium heath and peaty sites. We hypothesize that high ammonium concentrations at the Racomitrium heath are related to the mineralization of microbial cell tissue during times of stress, largely in the absence of plant uptake. Due to the spatial heterogeneity in N leaching potential, a fine-scale approach to assessing surface water vulnerability to N leaching is recommended over the broad scale, critical loads approach currently in use, particularly for sensitive areas.

  16. RESPONSE OF UPLAND RICE GENOTYPES TO SOIL ACIDITY

    Technology Transfer Automated Retrieval System (TEKTRAN)

    In many parts of the world on highly weathered Oxisols, acidity is one of the major factors that contributes to the reduction of crop yields. In addition to liming, use of acid tolerant crop species or cultivars within species, is a complimentary solution to improve crop production on such soils. A ...

  17. Grain yield and arsenic uptake of upland rice inoculated with arbuscular mycorrhizal fungi in As-spiked soils.

    PubMed

    Wu, Fuyong; Hu, Junli; Wu, Shengchun; Wong, Ming Hung

    2015-06-01

    A pot trial was conducted to investigate the effects of three arbuscular mycorrhizal (AM) fungi species, including Glomus geosporum BGC HUN02C, G. versiforme BGC GD01B, and G. mosseae BGC GD01A, on grain yield and arsenic (As) uptake of upland rice (Zhonghan 221) in As-spiked soils. Moderate levels of AM colonization (24.1-63.1 %) were recorded in the roots of upland rice, and up to 70 mg kg(-1) As in soils did not seem to inhibit mycorrhizal colonization. Positive mycorrhizal growth effects in grain, husk, straw, and root of the upland rice, especially under high level (70 mg kg(-1)) of As in soils, were apparent. Although the effects varied among species of AM fungi, inoculation of AM fungi apparently enhanced grain yield of upland rice without increasing grain As concentrations in As-spiked soils, indicating that AM fungi could alleviate adverse effects on the upland rice caused by As in soils. The present results also show that mycorrhizal inoculation significantly (p?soils added with 70 mg?kg(-1) As. The present results suggest that AM fungi are able to mitigate the adverse effects with enhancing rice production when growing in As-contaminated soils. PMID:23292227

  18. Organic carbon transformations in high-Arctic peat soils: key functions and microorganisms.

    PubMed

    Tveit, Alexander; Schwacke, Rainer; Svenning, Mette M; Urich, Tim

    2013-02-01

    A substantial part of the Earths' soil organic carbon (SOC) is stored in Arctic permafrost peatlands, which represent large potential sources for increased emissions of the greenhouse gases CH(4) and CO(2) in a warming climate. The microbial communities and their genetic repertoire involved in the breakdown and mineralisation of SOC in these soils are, however, poorly understood. In this study, we applied a combined metagenomic and metatranscriptomic approach on two Arctic peat soils to investigate the identity and the gene pool of the microbiota driving the SOC degradation in the seasonally thawed active layers. A large and diverse set of genes encoding plant polymer-degrading enzymes was found, comparable to microbiotas from temperate and subtropical soils. This indicates that the metabolic potential for SOC degradation in Arctic peat is not different from that of other climatic zones. The majority of these genes were assigned to three bacterial phyla, Actinobacteria, Verrucomicrobia and Bacteroidetes. Anaerobic metabolic pathways and the fraction of methanogenic archaea increased with peat depth, evident for a gradual transition from aerobic to anaerobic lifestyles. A population of CH(4)-oxidising bacteria closely related to Methylobacter tundripaludum was the dominating active group of methanotrophs. Based on the in-depth characterisation of the microbes and their genes, we conclude that these Arctic peat soils will turn into CO(2) sources owing to increased active layer depth and prolonged growing season. However, the extent of future CH(4) emissions will critically depend on the response of the methanotrophic bacteria. PMID:22955232

  19. Organic carbon transformations in high-Arctic peat soils: key functions and microorganisms

    PubMed Central

    Tveit, Alexander; Schwacke, Rainer; Svenning, Mette M; Urich, Tim

    2013-01-01

    A substantial part of the Earths' soil organic carbon (SOC) is stored in Arctic permafrost peatlands, which represent large potential sources for increased emissions of the greenhouse gases CH4 and CO2 in a warming climate. The microbial communities and their genetic repertoire involved in the breakdown and mineralisation of SOC in these soils are, however, poorly understood. In this study, we applied a combined metagenomic and metatranscriptomic approach on two Arctic peat soils to investigate the identity and the gene pool of the microbiota driving the SOC degradation in the seasonally thawed active layers. A large and diverse set of genes encoding plant polymer-degrading enzymes was found, comparable to microbiotas from temperate and subtropical soils. This indicates that the metabolic potential for SOC degradation in Arctic peat is not different from that of other climatic zones. The majority of these genes were assigned to three bacterial phyla, Actinobacteria, Verrucomicrobia and Bacteroidetes. Anaerobic metabolic pathways and the fraction of methanogenic archaea increased with peat depth, evident for a gradual transition from aerobic to anaerobic lifestyles. A population of CH4-oxidising bacteria closely related to Methylobacter tundripaludum was the dominating active group of methanotrophs. Based on the in-depth characterisation of the microbes and their genes, we conclude that these Arctic peat soils will turn into CO2 sources owing to increased active layer depth and prolonged growing season. However, the extent of future CH4 emissions will critically depend on the response of the methanotrophic bacteria. PMID:22955232

  20. 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...

  1. 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

  2. Factors affecting the mobilization of DOC and metals in a peat soil under a warmer scenario

    NASA Astrophysics Data System (ADS)

    Carrera, Noela; Barreal, María. Esther; Briones, María. Jesús I.

    2010-05-01

    Most climate change models predict an increase of temperature of 3-5°C in Southern Europe by the end of this century (IPCC 2007). However, changes in summer precipitations are more uncertain, and although a decrease in rainfall inputs is forecasted by most models, the magnitude of this effect has not been assessed properly (Rowell & Jones 2006). Peatland areas are very sensitive to climate change. In Galicia they survive in upland areas where cold temperatures and continuous moisture supply allow their presence. Besides abiotic factors, alterations in soil fauna activities can also affect peat turnover. Among them, enchytraeids are usually the most numerous invertebrate group in these systems and both temperature and moisture content regulate their abundances and vertical distribution. Previous studies have demonstrated that changes in their populations associated to increasing temperatures can significantly affect metal mobilization, namely iron and aluminium, together with an important decline in the acidity of the soil solution, which possibly eliminates one of the critical mechanisms restricting DOC release (Carrera et al., 2009). In this study we investigated whether changes in water content of the peat soil and soil invertebrate activities associated to increasing temperatures could alter the mobilization rates of Fe and Al and in turn, DOC. 72 undisturbed soil cores (6 cm diameter x 10 cm deep) with their associated vegetation were taken from a blanket bog in Galicia (NW Spain). Back at the laboratory they were sliced horizontally into two layers, (0-5cm and 5-10cm) which were defaunated by means of a wet extraction. Thereafter, the two soil layers derived from the same core were introduced in each microcosm by placing them in their original position but separated by a 1 mm nylon mesh to allow the vertical movements of the organisms. Half of the experimental units were adjusted to the used moisture values observed in the field (80% SWC, H1), whereas in the remaining half the moisture content was decreased to a lower value so that the activities of the soil organisms remained unaffected (60%, H2). Sixty enchytraeid individuals were inoculated into 18 units of each moisture treatment resulting in two animal treatments (+E and -E). Nine replicates of each treatment were incubated at 14°C and the rest were maintained at 19°C. Changes in enchytraeid populations during incubation were monitored by using a parallel series of 120 experimental units consisting of plastic containers which contained defaunated soil samples (two soil layers) separated by the nylon mesh and with the two moisture treatments as the microcosms (H1 and H2) following the same procedures as before. Next, the same number of enchytraeids was re-inoculated in half of these experimental units (+E and -E). The experiment run for 13 weeks; every 15 days, enchytraeid numbers, DOC, Fe and Al content in the leachates collected from each individual layer were determined. Results showed that both high temperature and moisture values promoted enchytraeid reproduction, with most individuals concentrated in the upper layer. This abundant enchytraeid population favoured the mobilization of DOC, Fe and Al to the soil solution. These findings suggest that modifications in soil faunal populations due to abiotic changes could enhance organic matter decomposition, contributing to the destabilization of these peatland systems. Increasing leaching of dissolved organic matter and metals could have negative implications, not only in terms of possible feed-backs to global warming but also as potential contaminants for aquatic ecosystems. References • Carrera N., Barreal M.E., Gallego P. & Briones M.J.I. (2009). Soil invertebrates control peatland C fluxes in response to warming. Functional Ecology 23: 637-648. • IPCC 2007. Climate change 2007. The Physical Science Basis. Solomon S., Qin D., Manning M., Chen Z., Marquis M., Averyt K.B., Tignor M. & Miller H.L. (Eds.). Cambridge University Press, Cambridge, UK. • Rowell D.P. & Jones R.G. (2006). Causes and uncertainty of future summer drying over Europe. Climate Dynamics 27: 281-299.

  3. Impact of drainage on wettability of fen peat-moorsh soils

    NASA Astrophysics Data System (ADS)

    Szajdak, L.; Szaty?owicz, J.; Brandyk, T.

    2009-04-01

    High water retention in peat is attributed to structural voids (macro-pores) due to the partial degradation of the structure of peat-forming plants, and molecular absorption sites (micro-pores) associated with the formation of humic substances. Water retention by the heterogeneously-structured system in peat organic matter depends on the chemical structure of solid surfaces. These naturally wet solids, if dried sufficiently, lose the ability to rewet quickly when immersed in water. The ability of peat surfaces to attract and hold water is attributed to hydrophilic functional groups which characterize the organic substances of peat. The investigations of chemical and physical properties were performed for three different peat-moorsh soils located in the Biebrza River Valley in Poland. All examined soils were used as meadow. Soil samples were taken from two depths: 5-10 cm (moorsh) and 50-80 cm (peat). Total organic carbon (TOC), dissolved organic carbon (DOC) and humic acids (HA) extracted from these samples were analysed. Also basic physical properties such as ash content and bulk density were measured. Wetting behavior of soils was quantified using water drop penetration time test (WDPT) and measured values of the soil-water contact angle using sessile drop method. The measurements were conducted on air-dry soil samples which volumetric moisture content was not exceeding 7%. The significant differences in the concentrations of TOC, DOC and properties of HA between two investigated depth of among peat and moorsh samples were observed. The measured concentrations of total organic carbon in the considered soils ranged from 37.2 to 45.6%. Generally, the decrease of total organic carbon concentration with depth of profiles was observed. The contents of dissolved organic carbon in the soils ranged from 5.3 to 19.4%. The quantities of dissolved organic carbon decreased simultaneously with E4/E6 values and with the depth of the soil profiles. For the investigated peat's, an increase of the depth is accompanied by the decrease in the degree of humification or an increase in chemical maturity of HA. The measured values of the contact angle for investigated soils were in the range from 81.4? to 114.3? what indicates their high water repellency. The WDPT was positively correlated with total organic carbon, organic matter and humic acids content while ash content, soil bulk density, pH and absorbance were correlated negatively. The highest value of correlation coefficient (statistically significant) was obtained for relation between WDPT and ash content. The soil water contact angle was less correlated with peat-moorsh soil properties in comparison with WDPT with one exception pH. The pH against the contact angle indicates tendency of increasing the contact angle with decreasing pH.

  4. Shergottite Impact Melt Glasses Contain Soil from Martian Uplands

    NASA Technical Reports Server (NTRS)

    Rao, M. N.; McKay, D. S.

    2002-01-01

    Martian meteorite (shergottite) impact melt glasses that contain high concentrations of martian atmospheric noble gases and show significant variations in Sr-87/Sr-86 isotopic ratios are likely to contain Martian surface fines mixed with coarser regolith materials. The mixed soil constituents were molten due to shock at the time of meteoroid impact near the Martian surface and the molten glass got incorporated into the voids and cracks in some shergottite meteorites. Earlier, Rao et al. found large enrichments of sulfur (sulfate) during an electron-microprobe study of several impact melt glass veins and pods in EET79001,LithC thin sections. As sulfur is very abundant in Martian soil, these S excesses were attributed to the mixing of a soil component containing aqueously altered secondary minerals with the LithC precursor materials prior to impact melt generation. Recently, we studied additional impact melt glasses in two basaltic shergottites, Zagami and Shergotty using procedures similar to those described by Rao et al. Significant S enrichments in Zagami and Shergotty impact melt glass veins similar to the EET79001, LithC glasses were found. In addition, we noticed the depletion of the mafic component accompanied by the enrichment of felsic component in these impact melt glass veins relative to the bulk host rock in the shergottites. To explain these observations, we present a model based on comminution of basaltic rocks due to meteroid bombardment on martian regolith and mechanical fractionation leading to enrichment of felsics and depletion of mafics in the fine grained dust which is locally mobilized as a result of saltation and deflation due to the pervasive aeolian activity on Mars.

  5. Effect of simulated tillage on microbial autotrophic CO2 fixation in paddy and upland soils

    PubMed Central

    Ge, Tida; Wu, Xiaohong; Liu, Qiong; Zhu, Zhenke; Yuan, Hongzhao; Wang, Wei; Whiteley, A. S.; Wu, Jinshui

    2016-01-01

    Tillage is a common agricultural practice affecting soil structure and biogeochemistry. To evaluate how tillage affects soil microbial CO2 fixation, we incubated and continuously labelled samples from two paddy soils and two upland soils subjected to simulated conventional tillage (CT) and no-tillage (NT) treatments. Results showed that CO2 fixation (14C-SOC) in CT soils was significantly higher than in NT soils. We also observed a significant, soil type- and depth-dependent effect of tillage on the incorporation rates of labelled C to the labile carbon pool. Concentrations of labelled C in the carbon pool significantly decreased with soil depth, irrespective of tillage. Additionally, quantitative PCR assays revealed that for most soils, total bacteria and cbbL-carrying bacteria were less abundant in CT versus NT treatments, and tended to decrease in abundance with increasing depth. However, specific CO2 fixation activity was significantly higher in CT than in NT soils, suggesting that the abundance of cbbL-containing bacteria may not always reflect their functional activity. This study highlights the positive effect of tillage on soil microbial CO2 fixation, and the results can be readily applied to the development of sustainable agricultural management. PMID:26795428

  6. Effect of simulated tillage on microbial autotrophic CO2 fixation in paddy and upland soils

    NASA Astrophysics Data System (ADS)

    Ge, Tida; Wu, Xiaohong; Liu, Qiong; Zhu, Zhenke; Yuan, Hongzhao; Wang, Wei; Whiteley, A. S.; Wu, Jinshui

    2016-01-01

    Tillage is a common agricultural practice affecting soil structure and biogeochemistry. To evaluate how tillage affects soil microbial CO2 fixation, we incubated and continuously labelled samples from two paddy soils and two upland soils subjected to simulated conventional tillage (CT) and no-tillage (NT) treatments. Results showed that CO2 fixation (14C-SOC) in CT soils was significantly higher than in NT soils. We also observed a significant, soil type- and depth-dependent effect of tillage on the incorporation rates of labelled C to the labile carbon pool. Concentrations of labelled C in the carbon pool significantly decreased with soil depth, irrespective of tillage. Additionally, quantitative PCR assays revealed that for most soils, total bacteria and cbbL-carrying bacteria were less abundant in CT versus NT treatments, and tended to decrease in abundance with increasing depth. However, specific CO2 fixation activity was significantly higher in CT than in NT soils, suggesting that the abundance of cbbL-containing bacteria may not always reflect their functional activity. This study highlights the positive effect of tillage on soil microbial CO2 fixation, and the results can be readily applied to the development of sustainable agricultural management.

  7. Effect of simulated tillage on microbial autotrophic CO2 fixation in paddy and upland soils.

    PubMed

    Ge, Tida; Wu, Xiaohong; Liu, Qiong; Zhu, Zhenke; Yuan, Hongzhao; Wang, Wei; Whiteley, A S; Wu, Jinshui

    2016-01-01

    Tillage is a common agricultural practice affecting soil structure and biogeochemistry. To evaluate how tillage affects soil microbial CO2 fixation, we incubated and continuously labelled samples from two paddy soils and two upland soils subjected to simulated conventional tillage (CT) and no-tillage (NT) treatments. Results showed that CO2 fixation ((14)C-SOC) in CT soils was significantly higher than in NT soils. We also observed a significant, soil type- and depth-dependent effect of tillage on the incorporation rates of labelled C to the labile carbon pool. Concentrations of labelled C in the carbon pool significantly decreased with soil depth, irrespective of tillage. Additionally, quantitative PCR assays revealed that for most soils, total bacteria and cbbL-carrying bacteria were less abundant in CT versus NT treatments, and tended to decrease in abundance with increasing depth. However, specific CO2 fixation activity was significantly higher in CT than in NT soils, suggesting that the abundance of cbbL-containing bacteria may not always reflect their functional activity. This study highlights the positive effect of tillage on soil microbial CO2 fixation, and the results can be readily applied to the development of sustainable agricultural management. PMID:26795428

  8. Effects of copper and aluminum on the adsorption of sulfathiazole and tylosin on peat and soil.

    PubMed

    Pei, Zhiguo; Yang, Shuang; Li, Lingyun; Li, Chunmei; Zhang, Shuzhen; Shan, Xiao-quan; Wen, Bei; Guo, Baoyuan

    2014-01-01

    Effects of copper (Cu) and aluminum (Al) on the adsorption of sulfathiazole (STZ) and tylosin (T) to peat and soil were investigated using a batch equilibration method. Results show that Cu suppressed STZ adsorption onto peat and soil at pH<5.0 because of the electrostatic competition, while increased STZ adsorption at pH>5.0 due to the formation of STZ-Cu complexes and/or Cu bridge. In contrast, Al only decreased STZ adsorption at pH<6.0, and exerted slight effect on STZ adsorption at >6.0. As for T, both Cu and Al suppressed its adsorption over the entire pH range owing to three reasons: 1) electrostatic competition between Cu/Al and T(+); 2) Cu/Al adsorption made the soil and peat surface less negatively charged, which was unfavorable for T(+) adsorption; 3) the shrunken pore size of peat and soil retarded the diffusion of large-sized T into these pores. PMID:24201036

  9. Applied K fertilizer use efficiency in pineapples grown on a tropical peat soil under residues removal.

    PubMed

    Ahmed, Osumanu H; Ahmad, Husni M H; Musa, Hanafi M; Rahim, Anuar A; Rastan, Syed Omar S

    2005-01-21

    In Malaysia, pineapples are grown on peat soils, but most K fertilizer recommendations do not take into account K loss through leaching. The objective of this study was to determine applied K use efficiency under a conventionally recommended fertilization regime in pineapple cultivation with residues removal. Results showed that K recovery from applied K fertilizer in pineapple cultivation on tropical peat soil was low, estimated at 28%. At a depth of 0-10 cm, there was a sharp decrease of soil total K, exchangeable K, and soil solution K days after planting (DAP) for plots with K fertilizer. This decline continued until the end of the study. Soil total, exchangeable, and solution K at the end of the study were generally lower than prior values before the study. There was no significant accumulation of K at depths of 10-25 and 25-45 cm. However, K concentrations throughout the study period were generally lower or equal to their initial status in the soil indicating leaching of the applied K and partly explained the low K recovery. Potassium losses through leaching in pineapple cultivation on tropical peat soils need to be considered in fertilizer recommendations for efficient recovery of applied K. PMID:15674449

  10. Permafrost thaw and soil moisture driving CO2 and CH4 release from upland tundra

    NASA Astrophysics Data System (ADS)

    Natali, Susan M.; Schuur, Edward A. G.; Mauritz, Marguerite; Schade, John D.; Celis, Gerardo; Crummer, Kathryn G.; Johnston, Catherine; Krapek, John; Pegoraro, Elaine; Salmon, Verity G.; Webb, Elizabeth E.

    2015-03-01

    As permafrost degrades, the amount of organic soil carbon (C) that thaws during the growing season will increase, but decomposition may be limited by saturated soil conditions common in high-latitude ecosystems. However, in some areas, soil drying is expected to accompany permafrost thaw as a result of increased water drainage, which may enhance C release to the atmosphere. We examined the effects of ecosystem warming, permafrost thaw, and soil moisture changes on C balance in an upland tundra ecosystem. This study was conducted at a water table drawdown experiment, established in 2011 and located within the Carbon in Permafrost Experimental Heating Research project, an ecosystem warming and permafrost thawing experiment in Alaska. Warming and drying increased cumulative growing season ecosystem respiration by ~20% over 3 years of this experiment. Warming caused an almost twofold increase in decomposition of a common substrate in surface soil (0-10 cm) across all years, and drying caused a twofold increase in decomposition (0-20 cm) relative to control after 3 years of drying. Decomposition of older C increased in the dried and in the combined warmed + dried plots based on soil pore space 14CO2. Although upland tundra systems have been considered CH4 sinks, warming and ground thaw significantly increased CH4 emission rates. Water table depth was positively correlated with monthly respiration and negatively correlated with CH4 emission rates. These results demonstrate that warming and drying may increase loss of old permafrost C from tundra ecosystems, but the form and magnitude of C released to the atmosphere will be driven by changes in soil moisture.

  11. No-till and conventional-till cotton response to broiler litter fertilization in an upland soil: lint yield

    Technology Transfer Automated Retrieval System (TEKTRAN)

    The effectiveness of poultry litter as cotton fertilizer is not well documented for upland soils in the southeastern USA where cotton may be grown under no-till and other soil conservation practices. The objective of this research was to measure the response of cotton to broiler litter fertilization...

  12. SEASONAL PHOSPHATASE ACTIVITY IN THREE CHARACTERISTIC SOILS OF THE ENGLISH UPLANDS POLLUTED BY LONG-TERM ATMOSPHERIC NITROGEN DEPOSITION

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Phosphomonoesterase activities were determined monthly during a seasonal cycle in three characteristic soil types of the English uplands that have been subject to long-term atmospheric nitrogen deposition. Activities (µmol para-nitrophenol per gram soil dry wt per hour) ranged between 83.9 - 307 in...

  13. Distribution of radiocesium in the soil-plant systems of upland areas of Europe

    SciTech Connect

    Livens, F.R.; Horrill, A.D.; Singleton, D.L. )

    1991-04-01

    The distribution and behavior of Cs in the soil-plant systems at some upland sites in Northeastern Italy, Scotland, and Norway have been investigated. From the limited range of samples taken, there appears to be no dominant physicochemical control on the plant availability of Cs. The presence of micaceous minerals or illitic clays does not significantly inhibit Cs uptake, either because of recycling in the organic surface horizons or because of clay-organic complex formation. Lower plants (bryophytes and lichens) show the highest Cs accumulation. Of the higher plants, ericaceous species take up Cs more than the others.

  14. Phosphate addition and plant species alters microbial community structure in acidic upland grassland soil.

    PubMed

    Rooney, Deirdre C; Clipson, Nicholas J W

    2009-01-01

    Agricultural improvement (addition of fertilizers, liming) of seminatural acidic grasslands across Ireland and the UK has resulted in significant shifts in floristic composition, soil chemistry, and microbial community structure. Although several factors have been proposed as responsible for driving shifts in microbial communities, the exact causes of such changes are not well defined. Phosphate was added to grassland microcosms to investigate the effect on fungal and bacterial communities. Plant species typical of unimproved grasslands (Agrostis capillaris, Festuca ovina) and agriculturally improved grasslands (Lolium perenne) were grown, and phosphate was added 25 days after seed germination, with harvesting after a further 50 days. Phosphate addition significantly increased root biomass (p < 0.001) and shoot biomass (p < 0.05), soil pH (by 0.1 U), and microbial activity (by 5.33 mg triphenylformazan [TPF] g(-1) soil; p < 0.001). A slight decrease (by 0.257 mg biomass-C g(-1) soil; p < 0.05) in microbial biomass after phosphate addition was found. The presence of plant species significantly decreased soil pH (p < 0.05; by up to 0.2 U) and increased microbial activity (by up to 6.02 mg TPF g(-1) soil) but had no significant effect on microbial biomass. Microbial communities were profiled using automated ribosomal intergenic spacer analysis. Multidimensional scaling plots and canonical correspondence analysis revealed that phosphate addition and its interactions with upland grassland plant species resulted in considerable changes in the fungal and bacterial communities of upland soil. The fungal community structure was significantly affected by both phosphate (R = 0.948) and plant species (R = 0.857), and the bacterial community structure was also significantly affected by phosphate (R = 0.758) and plant species (R = 0.753). Differences in microbial community structure following P addition were also revealed by similarity percentage analysis. These data suggest that phosphate application may be an important contributor to microbial community structural change during agricultural management of upland grasslands. PMID:18581037

  15. Assessing the Impact of Land Management on Organic Matter Composition in Peat Soils

    NASA Astrophysics Data System (ADS)

    Savage, A.; Holden, J.; Wainwright, J.

    2010-05-01

    Peatlands are seen as important stores of terrestrial carbon, accounting for up to one-third of global soil carbon stocks. In some cases peatlands are shown to be emitters of carbon, in other cases carbon sinks depending on the site conditions and nature of degradation. However, carbon budget calculations carried out to date have a number of uncertainties associated with them and the composition of the carbon is generally not considered when determining carbon budgets. Carbon cycling in peat is driven by four key factors (Laiho, 2006):, environmental conditions (e.g. temperature, water table level), substrate quality (e.g. how recalcitrant the peat is), nutrients (e.g. nitrogen required to synthesis the carbon stocks) and microbial community (e.g. are the microbes present able to utilise the available substrate). Land management is also recognised as an additional driver, but the impacts of many types of management are poorly understood. Among the four drivers listed by Laiho (2006) substrate quality is seen as the most significant. To date, little work has been carried out to characterise the quality of organic matter in peat soils; rather crude estimates have been made as to the quantity of carbon that is stored in peatlands, yet without understanding the composition of the peat, limitations are imposed on calculations of rates of carbon loss from peatlands. This work seeks to examine how variations in the chemical composition of organic matter in peat varies with land use. The method published by Wieder and Starr (1998) was followed to determine eight fractions: soluble fats and waxes, hot water soluble, hollocellulose, cellulose, soluble phenolics, acid insoluble carbohydrates, water soluble carbohydrates and lignin. Samples were taken from burnt, grazed, drained, afforested and undisturbed sites at the Moor House UNESCO Biosphere Reserve in Northern England. The method was used to identify if differences were present in the recalcitrance of the peat and linked to gaseous carbon emissions data collected during fortnightly monitoring. R. Laiho (2006) Decomposition in peatlands: Reconciling seemingly contrasting results on the impacts of lowered water levels Soil Biology & Biochemistry, 38, 2011-2024. R.K. Wieder & S.T. Starr (1998) Quantitative determination of organic fractions in highly organic, Sphagnum peat soils Communications in Soil Science and Plant Analysis, 29, 847-857.

  16. Microbial activity of peat soils of boggy larch forests and bogs in the permafrost zone of central Evenkia

    NASA Astrophysics Data System (ADS)

    Grodnitskaya, I. D.; Karpenko, L. V.; Knorre, A. A.; Syrtsov, S. N.

    2013-01-01

    The microbial activity of peat soils was studied in boggy larch forests and in an oligo-mesotrophic bog in the basins of the Kochechum and Nizhnaya Tunguska rivers (central Evenkia). It was found that the organic matter transformation in the peat soils of all the plots is mainly performed by oligotrophic bacteria composing 88-98% of the total bacterial complex. The major contribution to the organic matter destruction belonged to the heterotrophic microorganisms, the activity of which depended on the permafrost depth and the soil temperature, the soil acidity, and the botanical composition of the peat. Peat soils were characterized by different activities as judged from their microbiological and biochemical parameters. The functioning of microbial communities in the studied ecotopes of the permafrost zone was within the range of natural variations, which pointed to their ecological stability.

  17. Screening of herbaceous plants for peat-enhanced rehabilitation of contaminated soil with oily sludge.

    PubMed

    Wang, Shijie; Zhang, Chao; Lu, Guilan; Li, Fasheng; Guo, Guanlin

    2016-01-01

    A batch pot experiment using nine herbaceous species were conducted for peat enhanced rehabilitation of contaminated soil with oily sludge in the initial contents of 0%, 1.3%, 7.4%, and 12.2%, respectively. The results showed that petroleum hydrocarbons removal, plant growth indices and enzyme activities varied depending on plant species and oil contents. Cotton, ryegrass and tall fescue were effective in the rehabilitation of oily sludge contaminated soils. The total petroleum hydrocarbon (TPH) removal ranged from 30.0% to 40.0% after 170days of treatment. Plant biomass was shown to be the preferred indicator for screening phytoremediation plant because it was closely correlated with TPH removal and enzyme activities. Peat-enhanced plant rehabilitation could be a good strategy for the treatment of oily sludge contaminated saline soils. PMID:26114406

  18. Production of dissolved organic carbon (DOC) and trihalomethane (THM) precursor from peat soils.

    PubMed

    Chow, Alex T; Tanji, Kenneth K; Gao, Suduan

    2003-11-01

    Water passing through the Sacramento-San Joaquin Delta contains elevated concentrations of dissolved organic carbon (DOC) and trihalomethane (THM) precursor relative to upstream waters from the Sacramento River and the San Joaquin River. Drainage from agricultural peat soils has been identified as one of the major sources of DOC and THM precursor. A series of controlled laboratory experiments were conducted to evaluate abiotic and biotic effects on the quantity and the nature of DOC and THM precursors produced from oxidized surface and reduced subsurface soils in the Delta. For abiotic effects, DOC was extracted from both soils with synthetic solutions containing a range of salinity (0-4 dS/m) and sodicity (0 to infinity ). The results showed that an increase in salinity significantly decreased the concentration of DOC in the soil-water from both soils but increased its aromaticity, as indicated by specific ultraviolet absorbance at 254 nm (SUVA). For biotic effects, peat soils were incubated over a range of temperatures (10 degrees C, 20 degrees C and 30 degrees C) and soil moisture contents (0.3-10 g water/g soil). After 8 weeks of incubation, only extracted DOC from flooded conditions and flooded and non-flooded cycles showed an increase in DOC. These findings indicate that neither salinity nor sodicity is the major factor for DOC production, but both can affect the solubility and mobility of DOC in the Delta soils. We believe wetting processes in oxidized peat soils produce significant amounts of DOC found in agricultural drainage discharged into the Delta waters. PMID:14511718

  19. Investigating methane flux dynamics in subtropical peat soils of the Everglades using hydrogeophysical methods

    NASA Astrophysics Data System (ADS)

    Comas, X.; Wright, W. J.; Heij, G.

    2012-12-01

    Methane is a dynamic atmospheric gas with high radiative forcing that directly influences climatic patterns. Peat soils are well recognized sources for atmospheric methane, and although the number of studies on methane dynamics has increased during the last two decades, most have focused on boreal peatlands. For that reason, low-latitude systems like the Everglades have traditionally been less studied, and have focused on discrete point measures (such as gas chambers) that provide little information on temporal patterns in methane flux variability. In this study, we present an array of hydrogeophysical techniques to investigate the temporal variability of methane dynamics in peat soils of the Everglades. Ground penetrating radar (GPR) is used here to estimate temporal changes in methane fluxes at different scales ranging from low frequency measurements in the field (1- 10 m), to high frequency measurements in peat blocks at the laboratory scale (<1 m). Discrete measurements in the field are combined with continuous measurements using a unique autonomous rail system at the laboratory scale to further constrain timing of methane releasing events. GPR measurements are paired with other techniques, including direct methods such as time-lapse cameras, gas traps and gas chromatography, and other indirect methods, such as capacitance probes. Our results show the potential of hydrogeophysical techniques to better understand: 1) the internal biogenic gas dynamics within the peat's matrix (i.e. methane production vs. release), 2) the temporal variability in methane gas releases (i.e. steady vs. episodic ebullition); and 3) the effect of atmospheric pressure on regulating ebullitive methane events. Our results suggest that ebullitive events in peat soils of the Everglades resulting in large rapid fluxes of methane to the atmosphere may occur during periods of high atmospheric pressure due to decreases in the bubble volume and subsequent increases in bubble mobility.

  20. Draft Genome Sequence of Paenibacillus sp. Strain MSt1 with Broad Antimicrobial Activity, Isolated from Malaysian Tropical Peat Swamp Soil

    PubMed Central

    Ong, Kuan Shion; Yule, Catherine M.; Gan, Han Ming; Lee, Sui Mae

    2014-01-01

    We report the draft genome sequence of Paenibacillus sp. strain MSt1, which has broad-range antimicrobial activity, isolated from tropical peat swamp soil. Genes involved in antimicrobial biosynthesis are found to be present in this genome. PMID:25301658

  1. Draft Genome Sequence of Paenibacillus sp. Strain MSt1 with Broad Antimicrobial Activity, Isolated from Malaysian Tropical Peat Swamp Soil.

    PubMed

    Aw, Yoong Kit; Ong, Kuan Shion; Yule, Catherine M; Gan, Han Ming; Lee, Sui Mae

    2014-01-01

    We report the draft genome sequence of Paenibacillus sp. strain MSt1, which has broad-range antimicrobial activity, isolated from tropical peat swamp soil. Genes involved in antimicrobial biosynthesis are found to be present in this genome. PMID:25301658

  2. [Distribution characteristics of soil profile nitrous oxide concentration in paddy fields with different rice-upland crop rotation systems].

    PubMed

    Liu, Ping-li; Zhang, Xiao-lin; Xiong, Zheng-qin; Huang, Tai-qing; Ding, Min; Wang, Jin-yang

    2011-09-01

    To investigate the dynamic distribution patterns of nitrous oxide (N2O) in the soil profiles in paddy fields with different rice-upland crop rotation systems, a special soil gas collection device was adopted to monitor the dynamics of N2O at the soil depths 7, 15, 30, and 50 cm in the paddy fields under both flooding and drainage conditions. Two rotation systems were installed, i.e., wheat-single rice and oilseed rape-double rice, each with or without nitrogen (N) application. Comparing with the control, N application promoted the N2O production in the soil profiles significantly (P < 0.01), and there existed significant correlations in the N2O concentration among the four soil depths during the whole observation period (P < 0.01). In the growth seasons of winter wheat and oilseed rape under drainage condition and with or without N application, the N2O concentrations at the soil depths 30 cm and 50 cm were significantly higher than those at the soil depths 7 cm and 15 cm; whereas in the early rice growth season under flooding condition and without N application, the N2O concentrations at the soil depth 7 cm and 15 cm were significantly higher than those at the soil depths 30 cm and 50 cm (P < 0.05). No significant differences were observed in the N2O concentrations at the test soil depths among the other rice cropping treatments. The soil N2O concentrations in the treatments without N application peaked in the transitional period from the upland crops cropping to rice planting, while those in the treatments with N application peaked right after the second topdressing N of upland crops. Relatively high soil N2O concentrations were observed at the transitional period from the upland crops cropping to rice planting. PMID:22126049

  3. Effect of peat on the accumulation and translocation of heavy metals by maize grown in contaminated soils.

    PubMed

    Stanislawska-Glubiak, Ewa; Korzeniowska, Jolanta; Kocon, Anna

    2015-03-01

    Incorporation of organic materials into soil improves the soil sorption capacity, while limiting the mobility of metals in soil and their availability to plants. These effects can be taken advantage for remediation of soils polluted with heavy metals. The objective of this study is to assess the remediatory potential of peat applied to soils with concomitant pollution with Cd, Pb, and Zn. Two 1-year experiments were run in microplots in which maize was grown as the test plant. The following treatments were compared on two soils (sandy soil and loess): (1) control, (2) heavy metals (HM), (3) HM?+?peat in a single dose, and (4) HM?+?peat in a double dose. Maize was harvested in the maturity stage; the biomass of roots and aerial parts, including grain and cobs, was measured. Besides, concentration of metals in all those plant parts and the net photosynthetic rate and transpiration rate were determined. The approach of using peat in soil remediation led to satisfactory results on sandy soil only. The application of peat to sandy soil caused significant changes in the accumulation of the metals and their translocation from roots to other parts of plants, which resulted in a higher intensity of photosynthesis and an increase in the maize biomass compared to the HM treatment. PMID:25331526

  4. Mississippi Basin Carbon Project: upland soil database for sites in Nishnabotna River basin, Iowa

    USGS Publications Warehouse

    Harden, J.W.; Fries, T.L.; Haughy, R.; Kramer, L.; Zheng, Shuhui

    2001-01-01

    The conversion of land from its native state to an agricultural use commonly results in a significant loss of soil carbon (Mann, 1985; Davidson and Ackerman, 1993). Globally, this loss is estimated to account for as much as 1/3 of the net CO2 emissions for the period of 1850 to 1980 (Houghton and others, 1983). Roughly 20 to 40 percent of original soil carbon is estimated to be lost as CO2 as a result of agricultural conversion, or "decomposition enhancement". Global models use this estimate along with land conversion data to provide agricultural contributions of CO2 emissions for global carbon budgets (Houghton and others, 1983; Schimel, 1995). Soil erosion rates are significantly (10X) higher on croplands than on their undisturbed equivalents (Dabney and others, 1997). Most of the concern over erosion is related to diminished productivity of the uplands (Stallings, 1957; McGregor and others, 1969; Rhoton, 1990) or to increased hazards and navigability of the lowlands in the late 1800's to early 1900's. Yet because soil carbon is concentrated at the soil surface, with an exponential decline in concentration with depth (Harden et al, 1999), it is clear that changes in erosion rates seen on croplands must also impact soil carbon storage and terrestrial carbon budgets as well. As yet, erosional losses of carbon are not included in global carbon budgets explicitly as a factor in land conversion nor implicitly as a portion of the decomposition enhancement. However, recent work by Lal and others (1995) and by Stallard (1998) suggests that significant amounts of eroded soil may be stored in man-made reservoirs and depositional environments as a result of agricultural conversion. Moreover, Stallard points out that eroding soils have the potential for replacing part of the carbon trapped in man-made reservoirs. If true, then the global carbon budget may grossly underestimate or ignore a significant sink term resulting from the burial of eroded soil.

  5. Mississippi Basin Carbon Project; upland soil database for sites in Yazoo Basin, northern Mississippi

    USGS Publications Warehouse

    Harden, J.W.; Fries, T.L.; Huntington, T.G.

    1999-01-01

    The conversion of land from its native state to an agricultural use commonly results in a significant loss of soil carbon (Mann, 1985; Davidson and Ackerman, 1993). Globally, this loss is estimated to account for as much as 1/3 of the net CO2 emissions for the period of 1850 to 1980 (Houghton et al, 1983). Roughly 20 to 40 percent of original soil carbon is estimated to be lost as CO2 as a result of agricultural conversion, or 'decomposition enhancement', and global models use this estimate along with land conversion data to provide agricultural contributions of CO2 emissions for global carbon budgets (Houghton and others, 1983; Schimel, 1995). As yet, erosional losses of carbon are not included in global carbon budgets explicitly as a factor in land conversion nor implicitly as a portion of the decomposition enhancement. However, recent work by Lal et al (1995) and by Stallard (1998) suggests that significant amounts of eroded soil may be stored in man-made reservoirs and depositional environments as a result of agricultural conversion. Moreover, Stallard points out that if eroding soils have the potential for replacing part of the carbon trapped in man-made reservoirs, then the global carbon budget may grossly underestimate or ignore a significant sink term resulting from the burial of eroded soil. Soil erosion rates are significantly (10X) higher on croplands than on their undisturbed equivalents (Dabney et al, 1997). Most of the concern over erosion is related to diminished productivity of the uplands (Stallings, 1957; McGregor et al, 1993; Rhoton and Tyler, 1990) or to increased hazards and navigability of the lowlands in the late 1800's to early 1900's. Yet because soil carbon is concentrated at the soil surface, with an exponential decline in concentration with depth, it is clear that changes in erosion rates seen on croplands must also impact soil carbon storage and terrestrial carbon budgets as well.

  6. Conversion of upland to paddy field specifically alters the community structure of archaeal ammonia oxidizers in an acid soil

    NASA Astrophysics Data System (ADS)

    Alam, M. S.; Ren, G. D.; Lu, L.; Zheng, Y.; Peng, X. H.; Jia, Z. J.

    2013-08-01

    The function of ammonia-oxidizing archaea (AOA) and bacteria (AOB) depends on the major energy-generating compounds (i.e., ammonia and oxygen). The diversification of AOA and AOB communities along ecological gradients of substrate availability in a complex environment have been much debated but rarely tested. In this study, two ecosystems of maize and rice crops under different fertilization regimes were selected to investigate the community diversification of soil AOA and AOB upon conversion of an upland field to a paddy field and long-term field fertilization in an acid soil. Real-time quantitative polymerase chain reaction of ammonia monooxygenase (amoA) genes demonstrated that the abundance of AOA was significantly stimulated after conversion of upland to paddy soils for more than 100 yr, whereas a slight decline in AOB numbers was observed. Denaturing gradient gel electrophoresis fingerprints of amoA genes further revealed remarkable changes in the community compositions of AOA after conversion of aerobic upland to flooded paddy field. Sequencing analysis revealed that upland soil was dominated by AOA within the soil group 1.1b lineage, whereas the marine group 1.1a-associated lineage predominated in AOA communities in paddy soils. Irrespective of whether the soil was upland or paddy soil, long-term field fertilization led to increased abundance of amoA genes in AOA and AOB compared with control treatments (no fertilization), whereas archaeal amoA gene abundances outnumbered their bacterial counterparts in all samples. Phylogenetic analyses of amoA genes showed that Nitrosospira cluster-3-like AOB dominated bacterial ammonia oxidizers in both paddy and upland soils, regardless of fertilization treatment. The results of this study suggest that the marine group 1.1a-associated AOA will be better adapted to the flooded paddy field than AOA ecotypes of the soil group 1.1b lineage, and indicate that long-term flooding is the dominant selective force driving the community diversification of AOA populations in the acid soil tested.

  7. The xanthine oxidase activity in different of secondary transformed peat-moorsh soils

    NASA Astrophysics Data System (ADS)

    Sty?a, Katarzyna; Wojciech Szajdak, Lech

    2010-05-01

    The investigations were carried out on the transect of peatland 4.5 km long, located in the Agroecological Landscape Park host D. Chlapowski in Turew (40 km South-West of Pozna?, West Polish Lowland). The sites investigation were located along Wysko? ditch. The following material was taken from four chosen sites marked as Zb?chy, Bridge, Shelterbelt and Hirudo in two layers: acrotelm (0-50 cm) and catotelm (50-100 cm). The object of this study was to characterize the biochemical properties by the determination of the xanthine oxidase activity in two layers (acrotelm and catotelm) of the four different peat-moorsh soils used as meadow. The xanthine oxidase activity was determined spectrophotometrically by measuring uric acid formation at ?max=290 nm with xanthine as substrate. In peat-moorsh soil the highest activities of xanthine oxidasewas observed in the Shelterbelt and whereas the lowest - in Zb?chy, Bridge and Hirudo. Activities of this enzyme in peat-moorsh soil ranged from 5.96 to 19.51 ?mol h-1g d.m soil. Increased activities of xanthine oxidase have been recorded on the depth 50-100 cm - catotelm (from 11.71 to 19.51 ?mol h-1g d.m soil) in comparison with the depth 0-50 cm - acrotelm (from 5.96 to 14.64 ?mol h-1g d.m soil). This work was supported by a grant No. N N305 3204 36 founded by Polish Ministry of Education.

  8. A cost-efficient method to assess carbon stocks in tropical peat soil

    NASA Astrophysics Data System (ADS)

    Warren, M. W.; Kauffman, J. B.; Murdiyarso, D.; Anshari, G.; Hergoualc'h, K.; Kurnianto, S.; Purbopuspito, J.; Gusmayanti, E.; Afifudin, M.; Rahajoe, J.; Alhamd, L.; Limin, S.; Iswandi, A.

    2012-11-01

    Estimation of belowground carbon stocks in tropical wetland forests requires funding for laboratory analyses and suitable facilities, which are often lacking in developing nations where most tropical wetlands are found. It is therefore beneficial to develop simple analytical tools to assist belowground carbon estimation where financial and technical limitations are common. Here we use published and original data to describe soil carbon density (kgC m-3; Cd) as a function of bulk density (gC cm-3; Bd), which can be used to rapidly estimate belowground carbon storage using Bd measurements only. Predicted carbon densities and stocks are compared with those obtained from direct carbon analysis for ten peat swamp forest stands in three national parks of Indonesia. Analysis of soil carbon density and bulk density from the literature indicated a strong linear relationship (Cd = Bd × 495.14 + 5.41, R2 = 0.93, n = 151) for soils with organic C content > 40%. As organic C content decreases, the relationship between Cd and Bd becomes less predictable as soil texture becomes an important determinant of Cd. The equation predicted belowground C stocks to within 0.92% to 9.57% of observed values. Average bulk density of collected peat samples was 0.127 g cm-3, which is in the upper range of previous reports for Southeast Asian peatlands. When original data were included, the revised equation Cd = Bd × 468.76 + 5.82, with R2 = 0.95 and n = 712, was slightly below the lower 95% confidence interval of the original equation, and tended to decrease Cd estimates. We recommend this last equation for a rapid estimation of soil C stocks for well-developed peat soils where C content > 40%.

  9. Dissolved Organic Carbon and Disinfection By-Product Precursor Release from Managed Peat Soils

    USGS Publications Warehouse

    Fleck, J.A.; Bossio, D.A.; Fujii, R.

    2004-01-01

    A wetland restoration demonstration project examined the effects of a permanently flooded wetland on subsidence of peat soils. The project, started in 1997, was done on Twitchell Island, in the Sacramento-San Joaquin Delta of California. Conversion of agricultural land to a wetland has changed many of the biogeochemical processes controlling dissolved organic carbon (DOC) release from the peat soils, relative to the previous land use. Dissolved organic C in delta waters is a concern because it reacts with chlorine, added as a disinfectant in municipal drinking waters, to form carcinogenic disinfection byproducts (DBPs), including trihalomethanes (THMs) and haloacetic acids (HAAs). This study explores the effects of peat soil biogeochemistry on DOC and DBP release under agricultural and wetland management. Results indicate that organic matter source, extent of soil organic matter decomposition, and decomposition pathways all are factors in THM formation. The results show that historical management practices dominate the release of DOC and THM precursors. However, within-site differences indicate that recent management decisions can contribute to changes in DOC quality and THM precursor formation. Not all aromatic forms of carbon are highly reactive and certain environmental conditions produce the specific carbon structures that form THMs. Both HAA and THM precursors are elevated in the DOC released under wetland conditions. The findings of this study emphasize the need to further investigate the roles of organic matter sources, microbial decomposition pathways, and decomposition status of soil organic matter in the release of DOC and DBP precursors from delta soils under varying land-use practices.

  10. EVALUATION OF ENHANCED VOC REMOVAL WITH SOIL FRACTURING IN THE SRS UPLAND UNIT

    SciTech Connect

    Riha, B

    2005-10-31

    The Environmental Restoration Technology Section (ERTS) of the Savannah River National Laboratory (SRNL) conducted pilot scale testing to evaluate the effectiveness of using hydraulic fracturing as a means to improve soil vapor extraction (SVE) system performance. Laboratory and field research has shown that significant amounts of solvents can be entrapped in low permeability zones by capillary forces and removal by SVE can be severely limited due to low flow rates, mass transfer resistance of the hydrophobic compounds by trapped interparticle water, and diffusion resistance. Introducing sand-filled fractures into these tight zones improves the performance of SVE by (1) increasing the overall permeability of the formation and thereby increasing SVE flow rates, (2) shortening diffusion pathways, and (3) increasing air permeability by improving pore water removal. The synergistic effect of the fracture well completion methods, fracture and flow geometry, and pore water removal appears to increase the rate of solvent mass removal over that of increasing flow rate alone. A field test was conducted where a conventional well in the SRS Upland Unit was tested before and after hydraulic fracturing. ERTS teamed with Clemson University through the South Carolina University and Education Foundation (SCUREF) program utilizing their expertise in fracturing and fracture modeling. The goals of the fracturing pilot testing were to evaluate the following: (1) The effect of hydraulic fractures on the performance of a conventional well. This was the most reliable way to remove the effects of spatial variations in permeability and contaminant distribution on relative well performance. It also provided data on the option of improving the performance of existing wells using hydraulic fractures. (2) The relative performance of a conventional SVE well and isolated hydraulic fractures. This was the most reliable indicator of the performance of hydraulic fractures that could be created in a full-scale implementation. The SVE well, monitoring point arrays and four fracturing wells were installed and the well testing has been completed. Four fractures were successfully created the week of July 25, 2005. The fractures were created in an open area at the bottom of steel well casing by using a water jet to create a notch in the soil and then injecting a guar-sand slurry into the formation. The sand-filled fractures increase the effective air permeability of the subsurface formation diffusion path lengths for contaminant removal. The primary metrics for evaluation were an increase in SVE flow rates in the zone of contamination and an increase in the zone of influence. Sufficient testing has been performed to show that fracturing in the Upland Unit accelerates SVE solvent remediation and fracturing can increase flow rates in the Upland Unit by at least one order of magnitude.

  11. Substrate Geochemistry and Soil Development in Boreal Forest and Tundra Ecosystems in the Yukon-Tanana Upland and Seward Peninsula, Alaska

    USGS Publications Warehouse

    Gough, L.P.; Crock, J.G.; Wang, B.; Day, W.C.; Eberl, D.D.; Sanzolone, R.F.; Lamothe, P.J.

    2008-01-01

    We report on soil development as a function of bedrock type and the presence of loess in two high latitude ecosystems (boreal forest and tundra) and from two regions in Alaska?the Yukon-Tanana Upland (YTU, east-central Alaska) and the Seward Peninsula (SP, far-west coastal Alaska). This approach to the study of 'cold soils' is fundamental to the quantification of regional geochemical landscape patterns. Of the five state factors in this study, bedrock and biota (ecosystem; vegetation zone) vary whereas climate (within each area) and topography are controlled. The influence of time is assumed to be controlled, as these soils are thousands of years old (late Quaternary to Holocene). The primary minerals in soils from YTU, developed over loess and crystalline bedrock (metamorphic and intrusive), are quartz, plagioclase, and 2:1 clays; whereas in the SP, where loess and metasedimentary bedrock (schist and quartzite) predominate, they are quartz and muscovite. The A horizon of both regions is rich in peat. Examination of the ratio of mobile (K2O, CaO, and Fe2O3) to immobile (TiO2) major oxides, within each region, shows that very little difference exists in the chemical weathering of soils developed between the two ecosystems examined. Differences were observed between tundra soils developed in the two regions. These differences are most probably due to the dissimilarity in the geochemical importance of both loess and bedrock. A minimal loss of cadmium with soil depth is seen for soils developed over YTU crystalline bedrock in the boreal forest environments. This trend is related to the mobility of cadmium in these soils as well as to its biogenic cycling. Major differences were observed in the proportion of cadmium and zinc among the A, B, and C horizon material sequestered in various soil fractions as measured by sequential soil extractions. These trends followed such variables as the decrease with depth in organic matter, the change in clay minerals, and the change in the proportion of oxides/hydroxides. An analysis of the bulk soil mineralogy and the relation between CaO and MgO and Al2O3 and Fe2O3 indicates that the silty textured soils of the YTU are predominantly eolian (that is, of late Tertiary or Quaternary age) but not broad-regional in origin. Their composition instead is probably the result of locally derived dusts as well as input from long-term, in-place bedrock weathering.

  12. Fire effects on peat and organo-mineral soils of Meshchera plain

    NASA Astrophysics Data System (ADS)

    Tsibart, Anna; Koshovskii, Timur; Gamova, Natalia; Kovach, Roman

    2015-04-01

    The fire effects the soil properties depend on soil type and on their vulnerability to fires. The most of available data is devoted to changes in organo-mineral soils. But the peat fires can cause deeper changes in soil profiles, especially in case of drained peat soils. Now the lack of information exists in the sphere of the comparison of these fire types on soil cover. Meshchera plain (Moscow and Ryazan Regions, Russia) has different soil types. Moreover peatlands were partly drained, and the plain was affected by numerous fires of different time. So there is a need of detailed post-fire soil investigations in this region. During current research the soils Meshchera plain subjected by wildfires of 2002, 2007, 2010 and 2012 were studied. A total of 32 profiles including background and post-fire histosols, histic and sod podzols were investigated. Moreover the detailed description of vegetation cover was conducted. The samples were taken from genetic horizons. The morfological properties of soil profiles were sudied and the samples were analysed on organic carbon, pH, macroelements, magnetic susceptibility. After the wildfires changes in morfological and physico-chemical properties of soils were detected in most cases. The formation of ash and charry horizons was observed only in cases of peat soils affecetd by intense fires, and all post-fire drained peat soils had thick ash horizons even after 10 years after the fires. The significant loss of organic matter took place after burning. But almost immediately after the fires new stage of humus formation usually started. For instance, in post-fire histosols in 2 years after the burning the content of organic carbon reached to 10-12 % in upper horizons. ph values in background histosols were approximately 4-5. After the fire pH increased in these soil type to 8, and two years after the fire event pH decreased to 6-7. In podzols pH values returned to the pre-fire level 4-5 in two years. The magnetic susceptibility of soil samples in background histosols was 2-40 10-6 cm3/g. After the fires it increased in ash horizons up to 250 10-6 cm3/g. In sod podzols the changes also occurred. Background podzols had 2- 510-6 cm3/g. Post-fire horizons had up to 50- 6010-6 cm3/g after the fires. And even 10 years later the differences between post-fire and background soils preserved. So this parameter could be used as an indicator of fire events in soil profiles. After the fire the significant changes occurred in horizon mineral composition. Ash horizons had elevated concentrations of Al2O3 (9-17%), Fe2O3 (4-11%), P2O3 (1-1,8 %), CaO (1,9-2,8 %) and K2O (0,1-1,9%). The observed trends were similar for histosols and for histic podzols. And the changes in horizon mineral composition remained 2 and 10 years after the fire. So the more significant morphological and chemical changes occurred in the profiles of histosols, especially fire altered the soils of drained peatlands. These soil type keeps changes even 10 years after the fires.

  13. Biochar as a Substitute for Peat in Greenhouse Growing Media: Soil Water Characteristics and Carbon Leaching Dynamics

    NASA Astrophysics Data System (ADS)

    Johnson, M. S.; Hilbert, I.; Jollymore, A. J.

    2012-12-01

    Biochar (charcoal derived from waste biomass via pyrolysis) has the potential to be used as part of regional scale carbon sequestration strategies. By providing a stable form of carbon that is resistant to decay in soils, biochar can be utilized in a wide range of applications to improve the sustainability of land use management practices. Due to its high water holding capacity, surface area and charge density, it could provide a substitute for peat that is widely used in horticultural activities. Globally, peat production in 2010 amounted to 23.4 Mt, with more than a third of this used for horticulture. In Canada, essentially all peat produced is used for horticulture, with each ton of peat extracted also contributing about 0.7 t CO2e in combined greenhouse gas emissions related to production, transportation and use of peat. We evaluated biochar produced on farm from red alder as a peat substitute in terms of soil water characteristics and carbon leaching in greenhouse growing media (e.g. potting mix). Biochar mixing ratios of 10% (v/v) and greater provided water holding capacity equivalent to peat-based potting mixes. We also present results from a laboratory wetting experiment in which we characterized leachate for dissolved organic carbon (DOC) concentration and DOC characteristics using spectral methods (uV-Vis and fluorescence spectroscopy).

  14. The influence of different types of grassland on soil quality in upland areas of Czech Republic.

    PubMed

    Sarapatka, B; Cizkova, S

    2014-05-01

    The diversity of grassland in upland areas of Czech Republic was studied on selected soil characteristics of these biotopes. In the first phase, 44 soil characteristics were studied and mutual correlations were found between many of them. In the following phase characteristics were chosen which correlated most with other soil characteristics and, at the same time, were easy to evaluate in practise. A great number of correlations were also evidenced between many soil characteristics and the content of humus and nitrogen, which are closely linked to organic matter in soil. In studying these characteristics on selected areas with different types of grassland and consequential cluster analysis and further evaluation, the grassland plots were divided into three groups, from newly established vegetation to species-rich communities. Non-parametric analysis was carried out on the results and a statistically significant difference was proved between the species rich and poorvegetation and carbon and nitrogen content of the soil. Slightly different humus quality (higher amount of HA) was also found under richer vegetation. These results show that at 0-20 cm layer, 58.9 tonnes of carbon ha? was measured under species-poor pastureland and 106.1 tonnes of carbon ha under species-rich vegetation. The results showed that besides supporting species diversity, the described quality change can also be important for carbon sequestration. The difference of about 40-50 tonnes of carbon ha and converting 10% of grassland in the Czech Republic to species-rich vegetation would mean sequestration of about 3.9 Mt carbon. If only agroenvironmentally subsidized areas are converted, carbon sequestration in such vegetation could amountto 1.7 Mt. PMID:24812999

  15. Modeling relationships between water table depth and peat soil carbon loss in Southeast Asian plantations

    NASA Astrophysics Data System (ADS)

    Carlson, Kimberly M.; Goodman, Lael K.; May-Tobin, Calen C.

    2015-07-01

    Plantation-associated drainage of Southeast Asian peatlands has accelerated in recent years. Draining exposes the upper peat layer to oxygen, leading to elevated decomposition rates and net soil carbon losses. Empirical studies indicate positive relationships between long-term water table (WT) depth and soil carbon loss rate in peatlands. These correlations potentially enable using WT depth as a proxy for soil carbon losses from peatland plantations. Here, we compile data from published research assessing WT depth and carbon balance in tropical plantations on peat. We model net carbon loss from subsidence studies, as well as soil respiration (heterotrophic and total) from closed chamber studies, as a function of WT depth. WT depth across all 12 studies and 59 sites is 67 ± 20 cm (mean ± standard deviation). Mean WT depth is positively related to net carbon loss, as well as soil respiration rate. Our models explain 45% of net carbon loss variation and 45-63% of soil respiration variation. At a 70 cm WT depth, the subsidence model suggests net carbon loss of 20 tC ha-1 yr-1 (95% confidence interval (CI) 18-22 tC ha-1 yr-1) for plantations drained for >2 yr. Closed chamber-measured total soil respiration at this depth is 20 tC-CO2 ha-1 yr-1 (CI 17-24 tC-CO2 ha-1 yr-1) while heterotrophic respiration is 17 tC-CO2 ha-1 yr-1 (CI 14-20 tC-CO2 ha-1 yr-1), ˜82% of total respiration. While land use is not a significant predictor of soil respiration, WT depths are greater at acacia (75 ± 16 cm) than oil palm (59 ± 15 cm) sample sites. Improved spatio-temporal sampling of the full suite of peat soil carbon fluxes—including fluvial carbon export and organic fertilizer inputs—will clarify multiple mechanisms leading to carbon loss and gain, supporting refined assessments of the global warming potential of peatland drainage.

  16. Spatial Heterogeneity in the Properties of High-Moor Peat Soils under Local Pyrogenesis in Northeastern Sakhalin

    NASA Astrophysics Data System (ADS)

    Lipatov, D. N.; Shcheglov, A. I.; Manakhov, D. V.; Brekhov, P. T.

    2016-02-01

    The structure and properties of oligotrophic peat, oligotrophic peat gley, and pyrogenic oligotrophic peat soils identified on a plot 0.5 km2 in area in the northeast of Sakhalin Island have been studied. The vertical distributions of physicochemical, chemical, and ecotoxicological parameters in the profiles of some bog soil groups have been considered. An increase in ash content, a less acid reaction, and a deficit of available nitrogen and potassium have been revealed in the upper horizons of pyrogenic soils. No accumulation of mobile heavy metals is manifested in the pyrogenic horizons of peat soils. Statistical parameters of the spatial variation in pHKCl and total acidity, as well as the contents of ash, available phosphorus, exchangeable potassium, ammonium and nitrate nitrogen, mobile heavy metals (Cr, Ni, Cu, Zn, Cd, Pb), and benzo[ a]pyrene, have been calculated for the moss and sublitter horizons. The variation coefficients are 30-100% for most of the studied parameters and reach 100-200% for available phosphorus; ammonium nitrogen; and mobile Ni, Cu, Zn, and Cd. An increase in the content of benzo[ a]pyrene, although without MPC exceedance, is noted in the moss of pyrogenic soils and the peat horizons untouched by fires.

  17. Multiple season, field scale exploration of biogenic gas dynamics in two peat soils of the Florida Everglades using hydrogeophysics

    NASA Astrophysics Data System (ADS)

    Wright, W. J.; Comas, X.; Mount, G. J.; McClellan, M. D.

    2014-12-01

    Peatlands are known to release significant amounts of methane (CH4) and carbon dioxide (CO2) to the atmosphere. However, uncertainties still remain regarding the spatio-temporal distribution and triggering mechanisms of gas releasing events from peat soils. Furthermore, most research regarding peatland gas dynamics has historically been focused on high latitude peatlands, while recent works have suggested gas production rates from low-latitude peat soils may be higher than those from colder climates. Varying temporal and spatial scales have also shown marked differences in flux rates, thus questioning the appropriate scale for gas flux quantification. Ground penetrating radar (GPR) is a geophysical tool that has successfully been used in the past to non-invasively investigate the release of biogenic gasses from northern peat soils, and has only recently been used in the subtropical Florida Everglades. This study is based on an array of measurements at four field sites, spanning two different peat types (Loxahatchee and Everglades peats) of the Florida Everglades over a period of two years. At each site, gas contents within the soil are monitored using the GPR method, which is supported by direct gas flux measurements using flux chambers and time-lapse photography, and surface deformation is monitored using differential leveling. Resulting data highlight the variability of gas dynamics based on spatial, temporal, and soil compositional differences.

  18. [Responses of soil nematode communities to long-term application of inorganic fertilizers in upland red soil].

    PubMed

    Zhang, Wei; Liu, Man-Qiang; He, Yuan-Qiu; Fan, Jian-Bo; Chen, Yan

    2014-08-01

    Soil biota plays a key role in ecosystem functioning of red soil. Based on the long-term inorganic fertilization field experiment (25-year) in an upland red soil, the impacts of different inorganic fertilization managements, including NPK (nitrogen, phosphorus and potassium fertilizers), NPKCaS (NPK plus gypsum fertilizers), NP (nitrogen and phosphorus fertilizers), NK (nitrogen and potassium fertilizers) and PK (phosphorus and potassium fertilizers), on the assemblage of soil nematodes during the growing period of peanut were investigated. Significant differences among the treatments were observed for total nematode abundance, trophic groups and ecological indices (P < 0.01). The total nematode abundance decreased in the order of PK > NPKCaS > NPK > NP > NK. The total number of nematodes was significantly higher in NPKCaS and PK than in NPK, NP and NK except in May. Plant parasitic nematodes were the dominant trophic group in all treatments excepted in NPKCaS, and their proportion ranged between 38% and 65%. The dominant trophic group in NPKCaS was bacterivores and represented 42.1%. Furthermore, the higher values of maturity index, Wasilewska index and structure index in NPKCaS indicated that the combined application of NPK and gypsum could remarkably relieve soil acidification, resulting in a more mature and stable soil food web structure. While, that of the NK had the opposite effect. In conclusion, our study suggested that the application of both gypsum and phosphate is an effective practice to improve soil quality. Moreover, the analysis of nematode assemblage is relevant to reflect the impact of different inorganic fertilizer on the red soil ecosystem. PMID:25509090

  19. Plant soil interactions alter carbon cycling in an upland grassland soil

    PubMed Central

    Thomson, Bruce C.; Ostle, Nick J.; McNamara, Niall P.; Oakley, Simon; Whiteley, Andrew S.; Bailey, Mark J.; Griffiths, Robert I.

    2013-01-01

    Soil carbon (C) storage is dependent upon the complex dynamics of fresh and native organic matter cycling, which are regulated by plant and soil-microbial activities. A fundamental challenge exists to link microbial biodiversity with plant-soil C cycling processes to elucidate the underlying mechanisms regulating soil carbon. To address this, we contrasted vegetated grassland soils with bare soils, which had been plant-free for 3 years, using stable isotope (13C) labeled substrate assays and molecular analyses of bacterial communities. Vegetated soils had higher C and N contents, biomass, and substrate-specific respiration rates. Conversely, following substrate addition unlabeled, native soil C cycling was accelerated in bare soil and retarded in vegetated soil; indicative of differential priming effects. Functional differences were reflected in bacterial biodiversity with Alphaproteobacteria and Acidobacteria dominating vegetated and bare soils, respectively. Significant isotopic enrichment of soil RNA was found after substrate addition and rates varied according to substrate type. However, assimilation was independent of plant presence which, in contrast to large differences in 13CO2 respiration rates, indicated greater substrate C use efficiency in bare, Acidobacteria-dominated soils. Stable isotope probing (SIP) revealed most community members had utilized substrates with little evidence for competitive outgrowth of sub-populations. Our findings support theories on how plant-mediated soil resource availability affects the turnover of different pools of soil carbon, and we further identify a potential role of soil microbial biodiversity. Specifically we conclude that emerging theories on the life histories of dominant soil taxa can be invoked to explain changes in soil carbon cycling linked to resource availability, and that there is a strong case for considering microbial biodiversity in future studies investigating the turnover of different pools of soil carbon. PMID:24058360

  20. The Dependence of Peat Soil Hydraulic Conductivity on Dominant Vegetation Type in Mountain Fens

    NASA Astrophysics Data System (ADS)

    Crockett, A. C.; Ronayne, M. J.; Cooper, D. J.

    2014-12-01

    The peat soil within fen wetlands provides water storage that can substantially influence the hydrology of mountain watersheds. In this study, we investigated the relationship between hydraulic conductivity and vegetation type for fens occurring in Rocky Mountain National Park (RMNP), Colorado, USA. Vegetation in RMNP fens can be dominated by woody plants and shrubs, such as willows; by mosses; or by herbaceous plants such as sedges. Fens dominated by each vegetation type were selected for study. Six fens were investigated, all of which are in the Colorado River watershed on the west side of RMNP. For each site, soil hydraulic conductivity was measured at multiple locations using a single-ring infiltrometer. As a result of the shallow water table in these fens (the water table was always within 10 cm of the surface), horizontal hydraulic gradients were produced during the field tests. The measured infiltration rates were analyzed using the numerical model HYDRUS. In order to determine the hydraulic conductivity, a parameter estimation problem was solved using HYDRUS as the forward simulator. Horizontal flow was explicitly accounted for in the model. This approach produced more accurate estimates of hydraulic conductivity than would be obtained using an analytical solution that assumes strictly vertical flow. Significant differences in hydraulic properties between fens appear to result at least in part from the effects of different dominant vegetation types on peat soil formation.

  1. CARBON MONOXIDE FLUXES OF DIFFERENT SOIL LAYERS IN UPLAND CANADIAN BOREAL FORESTS

    EPA Science Inventory

    Dark or low-light carbon monoxide fluxes at upland Canadian boreal forest sites were measured on-site with static chambers and with a laboratory incubation technique using cores from different depths at the same sites. Three different upland black spruce sites, burned in 1987,199...

  2. Investigating carbon flux variability in subtropical peat soils of the Everglades using hydrogeophysical methods

    NASA Astrophysics Data System (ADS)

    Comas, Xavier; Wright, William

    2014-08-01

    The spatial and temporal variability in accumulation and release of greenhouse gases (mainly methane and carbon dioxide) to the atmosphere from peat soils remains very uncertain. The use of near-surface geophysical methods such as ground penetrating radar (GPR) has proven useful during the last decade to expand scales of measurement as related to in situ gas distribution and dynamics beyond traditional methods (i.e., gas chambers). However, this approach has focused exclusively on boreal peatlands, while no studies in subtropical systems like the Everglades using these techniques exist. In this paper GPR is combined with gas traps, time-lapse cameras, gas chromatography, and surface deformation measurements to explore biogenic gas dynamics (mainly gas buildup and release) in two locations in the Everglades. Similar to previous studies in northern peatlands, our data in the Everglades show a statistically significant correlation between the following: (1) GPR-estimated gas content and gas fluxes, (2) GPR-estimated gas content and surface deformation, and (3) atmospheric pressure and both GPR-estimated gas content and gas flux. From these results several gas-releasing events ranging between 33.8 and 718.8 mg CH4 m-2 d-1 were detected as identified by the following: (1) decreases in GPR-estimated gas content within the peat matrix, (2) increases in gas fluxes captured by gas traps and time-lapse cameras, and (3) decreases in surface deformation. Furthermore, gas-releasing events corresponded to periods of high atmospheric pressure. Changes in gas accumulation and release were attributed to differences in seasonality and peat soil type between sites. These results suggest that biogenic gas releases in the Everglades are spatially and temporarily variable. For example, flux events measured at hourly scales were up to threefold larger when compared to daily fluxes, therefore suggesting that flux measurements decline when averaged over longer time spans. This research therefore questions what the appropriate spatial and temporal scale of measurement is necessary to properly capture the dynamics of biogenic gas release in subtropical peat soils.

  3. Technical Note: Development of an automated lysimeter for the calculation of peat soil actual evapotranspiration

    NASA Astrophysics Data System (ADS)

    Proulx-McInnis, S.; St-Hilaire, A.; Rousseau, A. N.; Jutras, S.; Carrer, G.; Levrel, G.

    2011-05-01

    A limited number of publications in the literature deal with the measurement of actual evapotranspiration (AET) from a peat soil. AET is an important parameter in the description of water pathways of an ecosystem. In peatlands, where the water table is near the surface and the vegetation is composed of nonvascular plants without stomatal resistance, the AET measurement represents a challenge. This paper discusses the development of an automated lysimeter installed between 12 and 27 July 2010, at a 11-ha bog site, Pont-Rouge (42 km west of Quebec City, Canada). This system was made of an isolated block of peat, maintained at the same water level as the surrounding water table by a system of submersible pressure transmitters and pumps. The change in water level in millimetres in the isolated block of peat was used to calculate the water lost through evapotranspiration (ET) while accounting the precipitation. The rates of AET were calculated for each day of the study period. Temperature fluctuated between 17.2 and 23.3 C and total rainfall was 43.76 mm. AET rates from 0.6 to 6.9 mm day-1 were recorded, with a ?AET/?P ratio of 1.38. The estimated potential ET (PET) resulting from Thornthwaite's semi-empirical formula suggested values between 2.8 and 3.9 mm day-1. The average AET/PET ratio was 1.13. According to the literature, the results obtained are plausible. This system, relatively inexpensive and simple to install, may eventually be used to calculate AET on peaty soils in the years to come.

  4. Annual sulfate budgets for Dutch lowland peat polders: The soil is a major sulfate source through peat and pyrite oxidation

    NASA Astrophysics Data System (ADS)

    Vermaat, Jan E.; Harmsen, Joop; Hellmann, Fritz A.; van der Geest, Harm G.; de Klein, Jeroen J. M.; Kosten, Sarian; Smolders, Alfons J. P.; Verhoeven, Jos T. A.; Mes, Ron G.; Ouboter, Maarten

    2016-02-01

    Annual sulfate mass balances have been constructed for four low-lying peat polders in the Netherlands, to resolve the origin of high sulfate concentrations in surface water, which is considered a water quality problem, as indicated amongst others by the absence of sensitive water plant species. Potential limitation of these plants to areas with low sulfate was analyzed with a spatial match-up of two large databases. The peat polders are generally used for dairy farming or nature conservation, and have considerable areas of shallow surface water (mean 16%, range 6-43%). As a consequence of continuous drainage, the peat in these polders mineralizes causing subsidence rates generally ranging between 2 and 10 mm y-1. Together with pyrite oxidation, this peat mineralization the most important internal source of sulfate, providing an estimated 96 kg SO4 ha-1 mm-1 subsidence y-1. External sources are precipitation and water supplied during summer to compensate for water shortage, but these were found to be minor compared to internal release. The most important output flux is discharge of excess surface water during autumn and winter. If only external fluxes in and out of a polder are evaluated, inputs average 37 ± 9 and exports 169 ± 17 kg S ha-1 y-1. During summer, when evapotranspiration exceeds rainfall, sulfate accumulates in the unsaturated zone, to be flushed away and drained off during the wet autumn and winter. In some polders, upward seepage from early Holocene, brackish sediments can be a source of sulfate. Peat polders export sulfate to the regional water system and the sea during winter drainage. The available sulfate probably only plays a minor role in the oxidation of peat: we estimate that this is less than 10% whereas aerobic mineralization is the most important. Most surface waters in these polders have high sulfate concentrations, which generally decline during the growing season when aquatic sediments are a sink. In the sediment, this sulfur is reduced and binds iron more strongly than phosphorus, which can be released to the overlying water and potentially fuels eutrophication. About 76% of the sampled vegetation-sites exceeded a threshold of 50 mg l-1 SO4, above which sensitive species, such as Stratiotes aloides, and several species of Potamogeton were significantly less abundant. Thus high sulfate concentrations, mainly due to land drainage and consequent mineralization, appear to affect aquatic plant community composition.

  5. Mycotrophy of crops in rotation and soil amendment with peat influence the abundance and effectiveness of indigenous arbuscular mycorrhizal fungi in field soil.

    PubMed

    Vestberg, M; Saari, K; Kukkonen, S; Hurme, T

    2005-09-01

    Mycotrophy of previous crops has been shown to have an impact on arbuscular mycorrhizal fungi (AMF), and the growth and productivity of succeeding crops. We studied the impact of 3 years of cultivation of eight crops with different degrees of mycotrophy, including mycorrhizal (strawberry, rye, timothy, onion, caraway) and non-mycorrhizal (turnip rape, buckwheat, fiddleneck) hosts, as well as the impact of peat amendment, on the effectiveness, amount and diversity of indigenous AMF. A field experiment having a split-plot design with peat amendment as the main plot, crop cultivation as a sub-plot and three replications, was carried out on silt clay mineral soil in 1999-2001. A well-humified dark peat was applied immediately before establishment of the field experiment. Each year, the relative mycorrhizal effectiveness of soil collected in September, in terms of shoot dry weight (RME(DW)), was determined in a bioassay. In the 3rd year of the experiment, AMF spores were also extracted and identified from the field soil. Expressed as the mean of 3 years of cropping in unamended soil, the mycorrhizal crops strawberry and caraway maintained RME(DW) most effectively, while the values were lower in the non-host crops buckwheat, turnip rape and fiddleneck. In addition, the numbers of AM spores detected in soil were considerably greater during 3 years of strawberry cultivation. In soil under caraway, there were high numbers of AM spores compared to the other crops. In soil amended with peat, the situation was in some cases opposite of that of unamended soil; RME(DW) was highest in rye and onion and lowest in strawberry and caraway. The reasons behind the negative impact of peat on mycorrhizal effectiveness in strawberry soil may be due to the microbiological properties of peat. The importance of including mycotrophic species in crop rotations for maintaining high soil quality and for increasing yields of subsequent crops is discussed. PMID:16133257

  6. Soil-atmosphere trace gas exchange from tropical oil palm plantations on peat

    NASA Astrophysics Data System (ADS)

    Arn Teh, Yit; Manning, Frances; Zin Zawawi, Norliyana; Hill, Timothy; Chocholek, Melanie; Khoon Kho, Lip

    2015-04-01

    Oil palm is the largest agricultural crop in the tropics, accounting for 13 % of all tropical land cover. Due to its large areal extent, oil palm cultivation may have important implications not only for terrestrial stores of C and N, but may also impact regional and global exchanges of material and energy, including fluxes of trace gases and water vapor. In particular, recent expansion of oil palm into tropical peatlands has raised concerns over enhanced soil C emissions from degradation of peat, and elevated N-gas fluxes linked to N fertilizer application. Here we report our preliminary findings on soil carbon dioxide (CO2), methane (CH4) and nitrous oxide (N2O) fluxes from a long-term, multi-scale project investigating the C, N and greenhouse gas (GHG) dynamics of oil palm ecosystems established on peat soils in Sarawak, Malaysian Borneo. Flux chamber measurements indicate that soil CO2, CH4 and N2O fluxes averaged 20.0 ± 16.0 Mg CO2-C ha-1 yr-1, 37.4 ± 29.9 kg CH4-C ha-1 yr-1 and 4.7 ± 4.2 g N2O-N ha-1 yr-1, respectively. Soil CO2 fluxes were on par with other drained tropical peatlands; whereas CH4 fluxes exceeded observations from similar study sites elsewhere. Nitrous oxide fluxes were in a similar range to fluxes from other drained tropical peatlands, but lower than emissions from mineral-soil plantations by up to three orders of magnitude. Fluxes of soil CO2 and N2O were spatially stratified, and contingent upon the distribution of plants, deposited harvest residues, and soil moisture. Soil CO2 fluxes were most heavily influenced by the distribution of palms and their roots. On average, autotrophic (root) respiration accounted for approximately 78 % of total soil CO2 flux, and total soil respiration declined steeply away from palms; e.g. soil CO2 fluxes in the immediate 1 m radius around palms were up to 6 times greater than fluxes in inter-palm spaces due to higher densities of roots. Placement of harvest residues played an important - but secondary - role in modulating soil CO2 fluxes; soil respiration rates doubled in areas where harvest residues were deposited, reflecting an enhanced input of labile organic matter for decomposition. In contrast, N2O fluxes were best-predicted by the distribution of harvest residues, and were only weakly related to plant distributions or soil moisture. For example, N2O fluxes from harvest residue piles were up to twice of the overall plot-average. In contrast, N2O fluxes showed no clear pattern around palms or in inter-palm spaces; this finding is surprising because N fertilizers are applied within the 1 m radius around palms, and we expected to observe enhanced N2O fluxes in areas of greater fertilizer input. This suggests that palms may be a strong competitor for N in these ecosystems, and that fertilizer application may more closely match overall plant demand than in mineral-soil plantations. Overall, the spatial patterning of soil CO2 and N2O fluxes implies that soil biogeochemical processes are predictably distributed in space, potentially making it easier to model and constrain fluxes of these soil-derived GHGs.

  7. Nitrogen Turnover Processes in Low Temperatures in an Agricultural Peat Soil

    NASA Astrophysics Data System (ADS)

    Silvennoinen, H. M.; Hmlinen, R.; Koponen, H. T.; Martikainen, P. J.

    2009-12-01

    Nitrogen (N) cycling in agricultural soils has a key impact on the environment. Agricultural ecosystems are the most important sources of nitrous oxide (N2O), an important greenhouse gas, to the atmosphere. Additionally N fertilizers used to improve plant growth lead to enhanced N leaching and thereby to eutrophication of surrounding aquatic ecosystems. Microbial processes are normally enhanced by increase in temperature. Several recent studies have shown that although N2O emissions from agricultural soils are of microbiological origin, produced mainly in microbial reduction of nitrate (NO3-) via nitric oxide (NO) and N2O to molecular nitrogen (N2) (denitrification), the temperature response of N2O emissions is greatly variable and there is a lot of evidence of high emissions during cold periods (Koponen et al. 2006). Denitrification is, however, regulated by availability of inorganic N and therefore dependant not only on N fertilization but also on N turnover processes in soil. These processes include mineralization of organic N to ammonium (NH4+), oxidation of NH4+ to nitrite and NO3- (nitrification). These processes and their regulation especially in low temperatures are yet poorly understood. In this experiment, gross rates of N mineralization and nitrification and carbon dioxide production were studied in various temperatures ranging from -1.5 to 15 C. Soil samples were taken from grassland on peat soil in Southern Finland (60o49N, 23o30E) on September 8th 2008 from depths of 0-10 cm. Temperature responses of N gross mineralization and nitrification and of microbial respiration were measured in a laboratory experiment. The incubation temperatures used for experiments were 15, 5, 2.5, 1.5, 0.5, 0, -0.5 and -1.5 C. After 7 d temperature-specific incubation, gross rates of N mineralization and nitrification were determined with pool dilution technique in a 24 h incubation experiment. This study showed that N turnover processes in agricultural peat soil exhibit temperature anomalies. Carbon dioxide production decreased linearly with decrease in temperature, while gross nitrification and mineralization rates showed high variability in low temperatures and showed no significant differences between studied temperatures. References: Koponen HT , Duran CE, Maljanen M, Hytnen J, Martikainen PJ. 2006. Temperature responses of NO and N2O emissions from boreal organic soil. Soil Biology & Biogeochemistry 38, 1779-1787.

  8. Heavy metals uptake from contaminated soils as affected by peat, lime, and chelates

    SciTech Connect

    Albasel, N.; Cottenie, A.

    1985-01-01

    Heavy metal contamination of soils may reduce yields as well as the suitability for consumption of crop growth (Keeney et al., Leeper). In an effort to find possible ways to counter this danger, the effect of lime, chelating agents, and peat applied to Zn-, Cu- and Pb-contaminated soils on the uptake of metal ions were studied. Pot experiments with barley (Hordeum vulgare L.), perennial ryegrass (Lolium perenne) and Italian ryegrass (Lolium multiflorum) plants and soils, humic podzols (haplohumads) contaminated with Zn (3030 mg kg/sup -1/) and with Pb, Zn and Cu (110, 630, and 40 mg kg/sup -//sub 1/, respectively) were carried out. The concentration of the acid extracts of soils and plants were determined with the aid of the simultaneous direct reading spectrograph and atomic absorption. In all cases, raising the pH of the soil by liming appeared to be the most efficient method for reducing plant absorption of toxic micronutrients and heavy metals. However, the uptake of Fe and Mn was more markedly dependent on pH than that of Zn and Cu.

  9. Effects of temperature on microbial C metabolism in peat and mineral soil

    NASA Astrophysics Data System (ADS)

    Hagerty, S.; Dijkstra, P.; Miller, E.; Schwartz, E.; KOCH, G. W.; Hungate, B. A.

    2013-12-01

    Microbial metabolism, the main mechanism responsible for soil CO2 emissions, plays an important role in the global C cycle. Increased temperature generally stimulates decomposition and respiration, indicative of increased microbial C metabolism and possibly greater energy demand by microbes for growth and maintenance. Changes in microbial metabolism with temperature may manifest differently in microbial communities from soils with different C availability because it is generally expected that when more organic C is present, carbon use efficiency (CUE) will be lower and more CO2 will be released per unit C assimilated by microbes than when less C substrate is available. In this study we examined the effect of temperature on C processing in peat and mineral soil from the Marcel Experimental Forest in Minnesota. Samples were incubated for 7 days at 5, 10, 15, and 20C. We used position-specific 13C-labeled tracers to model C flux through the central C metabolic network (i.e. glycolysis, pentose phosphate pathway, and the citric acid cycle) and to asses the CUE of microbial communities. We also measured total CO2 production and microbial biomass, and we calculated the metabolic quotient (qCO2), which is the rate of CO2, respired per unit of microbial biomass. We found that temperature and soil type did not affect CUE and patterns of C flow through the central C metabolic network. Increased temperature stimulated respiration and decreased qCO2 in peat more than the mineral soil. These results suggest temperature affects rate of C cycling, but does not alter the relative demand for energy production and biosynthesis per unit substrate-C. This implies, in contrast to expectations that at higher temperatures more substrate will be used to offset greater demand for maintenance energy, warmer temperatures will not alter the balance of growth and maintenance energy by soil microbes. Moreover, substrate availability did not result in ';wasteful' C use, but increased C cycling rates. These findings may simplify the modeling of soil respiration with climatic warming.

  10. Analysing water level strategies to reduce soil subsidence in Dutch peat meadows

    NASA Astrophysics Data System (ADS)

    Querner, E. P.; Jansen, P. C.; van den Akker, J. J. H.; Kwakernaak, C.

    2012-06-01

    SummaryThe survival of peat meadows in the Netherlands is threatened by soil subsidence, less favourable conditions for farming and rising costs of water management. To support policy-making, a study examined possible future strategies for these meadows in the west of the Netherlands. Future scenarios with different water level strategies and climate scenarios were modelled with the SIMGRO regional hydrological model. The analysis focused on water level control strategies, in combination with subsurface drains, with the aim of reducing subsidence and minimising the water supply in dry periods. Subsurface drains were found to be a good measure to reduce subsidence, but more water had to be supplied. Based on the simulated water level control strategies an optimal scenario was found; it minimises the negative effects of the increased water supply. A scenario simulating the anticipated climate change appeared to have a great impact on the peat meadows. In the future the subsidence rate will increase and more water will have to be supplied to maintain the target surface water levels.

  11. Temperature, Water Content and Wet-Dry Cycle Effects on DOC Production and Carbon Mineralization in Agricultural Peat Soils.

    Technology Transfer Automated Retrieval System (TEKTRAN)

    A series of controlled laboratory experiments were utilized to examine factors affecting dissolved organic carbon (DOC) production and C mineralization rates over a range of conditions experienced resulting from agricultural practices in peat soils from the Sacramento-San Joaquin Delta. We conclude...

  12. Use of Computer-Aided Tomography (CT) Imaging for Quantifying Coarse Roots, Rhizomes, Peat, and Particle Densities in Marsh Soils

    EPA Science Inventory

    Computer-aided Tomography (CT) imaging was utilized to quantify wet mass of coarse roots, rhizomes, and peat in cores collected from organic-rich (Jamaica Bay, NY) and mineral (North Inlet, SC) Spartina alterniflora soils. Calibration rods composed of materials with standard dens...

  13. Heavy metal contamination from historic mining in upland soil and estuarine sediments of Egypt Bay, Maine, USA

    NASA Astrophysics Data System (ADS)

    Osher, L. J.; Leclerc, L.; Wiersma, G. B.; Hess, C. T.; Guiseppe, V. E.

    2006-10-01

    Concentrations of Cd, Cu, Pb and Zn in sediments of Egypt Bay in Hancock County, Maine, are elevated above background levels. The source of the contamination is Cu mining that occurred in the uplands adjacent to Egypt Stream between 1877 and 1885. Egypt Stream is a tributary to Egypt Bay. Egypt Bay is part of the Taunton Bay estuary system. The Hagan Mine was one of the mines extracting metals from the sulfide deposits in Downeast Maine north of Penobscot Bay. Metal concentrations were determined using ICP-AES after sample digestion with nitric acid. Soil collected from the coarse textured mine tailings pile contained elevated concentrations of Cd, Cu, Pb and Zn, but the majority of the surface soils at the Hagan Mine site were not contaminated. Estuary sediments from the surface to 100 cm depth were collected in four locations within Egypt Bay. Below 40 cm, metal concentrations in sediments were similar to those in uncontaminated upland soils. Metal concentrations in the estuary sediments between the surface and 26 cm were above background levels. According to 210Pb dating, the sediment at 26-34 cm depth was likely to have been deposited at the time the historic mines were in operation. Concentrations of Cd, Cu, Pb, and Zn in sediment from the 32-34 cm depth interval are similar to concentrations in the upland soil sample from the mine tailings pile. Elevated Pb concentrations in sediments from the surface to 24 cm are from atmospheric Pb deposition from anthropogenic sources. Sediment in the top 10 cm of the estuary has been mixed both by the polychaete worm Nereis virens and by those harvesting the worms for sale as fish bait.

  14. Development and testing of an improved model of the thermal behaviour of peat soils.

    NASA Astrophysics Data System (ADS)

    Kettridge, N.; Baird, A.

    2004-05-01

    Many biogeochemical processes in peats are temperature-sensitive. Despite this, little work has been done on characterising the thermal behaviour of peats. Most existing studies have looked only at 1-D thermal behaviour using simple models in which the thermal properties are constant with depth, and the temperature variation at the surface is specified from field measurements or is assumed to follow a sine wave. We report on the development and application of a more realistic thermal model of peat soils in which heat transfer is described by a system of `capacitors' or nodes and `resistors'. Its features include: 1. A realistic surface boundary condition where convective (sensible and latent) and radiative (short- and long- wave) heat transfers are accounted for by nodes representing the air/atmosphere above the peatland surface. 2. The ability to vary thermal properties with depth in order to simulate, for example, the effect of an unsaturated zone above the water table on thermal behaviour. 3. The ability to simulate 3-D patterns of heat transfer in patterned peatlands consisting of hummocks, lawns, hollows, and pools (microforms). In order that the model can be applied to a 3-D system, the standard large-scale parameterisation of the Penman-Monteith equation, used to calculate convective heat fluxes, has been improved. First, aerodynamic resistance has been calculated from newly developed sensitive self-logging atmometers, enabling measurement of potential evaporation at high frequencies and at different positions on and surrounding a microform, either at the ground surface or within the plant canopy. Secondly, dual probe heat pulse sensors (DPHPS) have enabled the measurement of soil thermal properties and volumetric water content of a small volume of soil at regular time intervals. In combination with measured water-table fluctuations, a stack of DPHPS within the unsaturated zone has enabled the accurate measurement of actual evapotranspiration, without the interference and labour requirements of a lysimeter. The model has been applied, in its 1-D form, to a Sphagnum hollow and lawn in order to evaluate these new approaches and to test the error that arises when advective heat transfer within the soil profile is ignored. Advective heat transfer has been ignored in the model because of the complex nature of unsaturated water transfer within Sphagnum litter and acrotelm peat. The prototype equipment enabled the successful parameterisation and accurate representation of the thermal behaviour of the Sphagnum hollow and lawn during dry periods. During wet periods model error increased slightly; however, negative feedback mechanisms at the surface boundary enabled the model to recover quickly. We discuss the future application of this model to a hummock-hollow complex and demonstrate how consideration of points 1, 2, and 3 above can lead to quite different patterns of heat transfer from those predicted in previous simple models.

  15. Time-scales of hydrological forcing on the geochemistry and bacterial community structure of temperate peat soils.

    PubMed

    Nunes, Flavia L D; Aquilina, Luc; de Ridder, Jo; Francez, Andr-Jean; Quaiser, Achim; Caudal, Jean-Pierre; Vandenkoornhuyse, Philippe; Dufresne, Alexis

    2015-01-01

    Peatlands are an important global carbon reservoir. The continued accumulation of carbon in peatlands depends on the persistence of anoxic conditions, in part induced by water saturation, which prevents oxidation of organic matter, and slows down decomposition. Here we investigate how and over what time scales the hydrological regime impacts the geochemistry and the bacterial community structure of temperate peat soils. Peat cores from two sites having contrasting groundwater budgets were subjected to four controlled drought-rewetting cycles. Pore water geochemistry and metagenomic profiling of bacterial communities showed that frequent water table drawdown induced lower concentrations of dissolved carbon, higher concentrations of sulfate and iron and reduced bacterial richness and diversity in the peat soil and water. Short-term drought cycles (3-9 day frequency) resulted in different communities from continuously saturated environments. Furthermore, the site that has more frequently experienced water table drawdown during the last two decades presented the most striking shifts in bacterial community structure, altering biogeochemical functioning of peat soils. Our results suggest that the increase in frequency and duration of drought conditions under changing climatic conditions or water resource use can induce profound changes in bacterial communities, with potentially severe consequences for carbon storage in temperate peatlands. PMID:26440376

  16. Time-scales of hydrological forcing on the geochemistry and bacterial community structure of temperate peat soils

    NASA Astrophysics Data System (ADS)

    Nunes, Flavia L. D.; Aquilina, Luc; De Ridder, Jo; Francez, André-Jean; Quaiser, Achim; Caudal, Jean-Pierre; Vandenkoornhuyse, Philippe; Dufresne, Alexis

    2015-10-01

    Peatlands are an important global carbon reservoir. The continued accumulation of carbon in peatlands depends on the persistence of anoxic conditions, in part induced by water saturation, which prevents oxidation of organic matter, and slows down decomposition. Here we investigate how and over what time scales the hydrological regime impacts the geochemistry and the bacterial community structure of temperate peat soils. Peat cores from two sites having contrasting groundwater budgets were subjected to four controlled drought-rewetting cycles. Pore water geochemistry and metagenomic profiling of bacterial communities showed that frequent water table drawdown induced lower concentrations of dissolved carbon, higher concentrations of sulfate and iron and reduced bacterial richness and diversity in the peat soil and water. Short-term drought cycles (3-9 day frequency) resulted in different communities from continuously saturated environments. Furthermore, the site that has more frequently experienced water table drawdown during the last two decades presented the most striking shifts in bacterial community structure, altering biogeochemical functioning of peat soils. Our results suggest that the increase in frequency and duration of drought conditions under changing climatic conditions or water resource use can induce profound changes in bacterial communities, with potentially severe consequences for carbon storage in temperate peatlands.

  17. Time-scales of hydrological forcing on the geochemistry and bacterial community structure of temperate peat soils

    PubMed Central

    Nunes, Flavia L. D.; Aquilina, Luc; de Ridder, Jo; Francez, André-Jean; Quaiser, Achim; Caudal, Jean-Pierre; Vandenkoornhuyse, Philippe; Dufresne, Alexis

    2015-01-01

    Peatlands are an important global carbon reservoir. The continued accumulation of carbon in peatlands depends on the persistence of anoxic conditions, in part induced by water saturation, which prevents oxidation of organic matter, and slows down decomposition. Here we investigate how and over what time scales the hydrological regime impacts the geochemistry and the bacterial community structure of temperate peat soils. Peat cores from two sites having contrasting groundwater budgets were subjected to four controlled drought-rewetting cycles. Pore water geochemistry and metagenomic profiling of bacterial communities showed that frequent water table drawdown induced lower concentrations of dissolved carbon, higher concentrations of sulfate and iron and reduced bacterial richness and diversity in the peat soil and water. Short-term drought cycles (3–9 day frequency) resulted in different communities from continuously saturated environments. Furthermore, the site that has more frequently experienced water table drawdown during the last two decades presented the most striking shifts in bacterial community structure, altering biogeochemical functioning of peat soils. Our results suggest that the increase in frequency and duration of drought conditions under changing climatic conditions or water resource use can induce profound changes in bacterial communities, with potentially severe consequences for carbon storage in temperate peatlands. PMID:26440376

  18. pp iii Transport of lead and diesel fuel through a peat soil near Juneau, AK: a pilot study

    NASA Astrophysics Data System (ADS)

    Deiss, Julian; Byers, Carl; Clover, Dave; D'Amore, Dave; Love, Alan; Menzies, Malcolm A.; Powell, Jim; Todd Walter, M.

    2004-10-01

    A set of peat column experiments was used to determine the transport potential of lead (Pb) and diesel range organics (DRO) in palustrine slope wetlands near Juneau, AK. This project is important to southeast Alaskan communities because limited land resources are forcing development of regional wetlands. This study was instigated by concerns that proposed modifications to a nearby rifle range using DRO-contaminated soil posed a potential risk to an anadromous fish-bearing stream 250 m from the site. Three pairs of peat columns were extracted from the rifle range for analysis, one pair along and two pairs across the natural bedding planes of the soil. One column in each pair was spiked with Pb and DRO and the other was used as a control. Approximately 1-year worth of water (171 cm) was passed through each column and leachate was collected at regular intervals. The results showed that substantial DRO transport only occurred along the bedding planes. Leads was surprisingly mobile, both along and across the bedding planes with estimated soil-water partition coefficients several orders of magnitude lower than commonly published values, probably because the peat was heavily Pb-loaded by lead from bullets and because the peat's acidic, organic-rich environment enhanced Pb mobility. The chemical outflow behavior agreed with a simple macropore transport model. These results underscore the need for caution when developing regional wetlands.

  19. Hydrochemical modelling of the retention and transport of metallic radionuclides in the soils of an upland catchment.

    PubMed

    Tipping, E

    1996-01-01

    The CHemistry of the Uplands Model (CHUM) describes the transport of chemicals through upland catchments with acid, organic-rich soils, by a combination of sub-models for equilibrium soil chemistry, hydrology, weathering, and nitrogen cycling. CHUM was used to simulate the retention and transport of metallic radionuclides (Co, Sr, Cs, UO(2), U(IV), Th, Am), in the soils of a small catchment in Cumbria, UK, for 2 years after their atmospheric deposition in a single hypothetical precipitation event. Export of radionuclides to streamwater is calculated to occur most readily following deposition of the dissolved elements at high water saturation of the catchment, when little incoming rainwater is required to make up the small moisture deficit of the organic surface horizon, and solutes can move to greater depths in the soil profile. Deposition when the catchment is drier, or of particulate radionuclides, leads to stronger retention. Radionuclide retention or transport depends on the strength of chemical interaction with the solid phases of the different soil horizons; this varies among the elements, and also with oxidation state, U(IV) species being more strongly retained than UO(2). For purely organic soils, the least strongly retained radionuclide is Cs, but the presence in the mineral soil horizon of small amounts of clay mineral with high selectivity towards Cs can markedly increase with high selectivity towards Cs can markedly increase its retention. For the actinides, binding by dissolved organic matter is important; for example, the rate of transport of Th to the stream is increased by more than two orders of magnitude by complexation with dissolved fulvic acid. The model assumptions suggest that, in the longer term, losses from the catchment of Co, Sr and Cs would take place on a time-scale of decades, whereas the actinides would be much more persistent. PMID:15093497

  20. Secondary successions of biota in oil-polluted peat soil upon different biological remediation methods

    NASA Astrophysics Data System (ADS)

    Melekhina, E. N.; Markarova, M. Yu.; Shchemelinina, T. N.; Anchugova, E. M.; Kanev, V. A.

    2015-06-01

    The effects of different bioremediation methods on restoration of the oil-polluted peat soil (Histosol) in the northernmost taiga subzone of European Russia was studied. The population dynamics of microorganisms belonging to different trophic groups (hydrocarbon-oxidizing, ammonifying, nitrifying, and oligonitrophilic) were analyzed together with data on the soil enzyme (catalase and dehydrogenase) activities, population densities of soil microfauna groups, their structures, and states of phytocenoses during a sevenyear-long succession. The remediation with biopreparations Roder composed of oil-oxidizing microorganisms-Roder with Rhodococcus rubber and R. erythropolis and Universal with Rhodotorula glutinis and Rhodococcus sp.-was more efficient than the agrochemical and technical remediation. It was concluded that the biopreparations activate microbiological oil destruction, thereby accelerating restoration succession of phytocenosis and zoocenosis. The succession of dominant microfauna groups was observed: the dipteran larvae and Mesostigmata mites predominant at the early stages were replaced by collembolans at later stages. The pioneer oribatid mite species were Tectocepheus velatus, Oppiella nova, Liochthonius sellnicki, Oribatula tibialis, and Eupelops sp.

  1. Water-soluble organic acids in cryomorphic peat soils of the southeastern Bol'shezemel'skaya tundra

    NASA Astrophysics Data System (ADS)

    Shamrikova, E. V.; Kaverin, D. A.; Pastukhov, A. V.; Lapteva, E. M.; Kubik, O. S.; Punegov, V. V.

    2015-03-01

    The composition of the water extracts, the pH, and the weight concentrations of the total organic carbon and low-molecular-weight organic acids in seasonally thawed and perennially frozen horizons of cryomorphic peat soils have been determined. The quantitative analysis of the acids converted to trimethylsilyl derivatives has been performed by gas chromatography and chromato-mass spectroscopy. Hydroxypropanoic, propanoic, and hydroxyethanoic acids are the prevailing acids (30-50, 10-20, and 10% of the total acids, respectively). Malic, glyceric, hexadionic, trihydroxybutanoic, ribonic, and other acids have also been detected. It has been shown that the differences in the genesis of the peat deposits significantly affect the composition and content of water-soluble organic compounds in soils on the soil-profile and landscape levels.

  2. Imaging tropical peatlands in Indonesia using ground penetrating radar (GPR) and electrical resistivity imaging (ERI): implications for carbon stock estimates and peat soil characterization

    NASA Astrophysics Data System (ADS)

    Comas, X.; Terry, N.; Slater, L.; Warren, M.; Kolka, R.; Kristijono, A.; Sudiana, N.; Nurjaman, D.; Darusman, T.

    2015-01-01

    Current estimates of carbon (C) storage in peatland systems worldwide indicate tropical peatlands comprise about 15% of the global peat carbon pool. Such estimates are uncertain due to data gaps regarding organic peat soil thickness and C content. Indonesian peatlands are considered the largest pool of tropical peat carbon (C), accounting for an estimated 65% of all tropical peat while being the largest source of carbon dioxide emissions from degrading peat worldwide, posing a major concern regarding long-term sources of greenhouse gases to the atmosphere. We combined a set of indirect geophysical methods (ground penetrating radar, GPR, and electrical resistivity imaging, ERI) with direct observations from core samples (including C analysis) to better understand peatland thickness in West Kalimantan (Indonesia) and determine how geophysical imaging may enhance traditional coring methods for estimating C storage in peatland systems. Peatland thicknesses estimated from GPR and ERI and confirmed by coring indicated variation by less than 3% even for small peat-mineral soil interface gradients (i.e. below 0.02). The geophysical data also provide information on peat matrix attributes such as thickness of organomineral horizons between peat and underlying substrate, the presence of wood layers, buttressed trees and soil type. These attributes could further constrain quantification of C content and aid responsible peatland management in Indonesia.

  3. Thermodynamics of peat-, plant-, and soil-derived humic acid sorption on kaolinite.

    PubMed

    Ghabbour, Elham A; Davies, Geoffrey; Goodwillie, Melissa E; O'Donaughy, Kelly; Smith, Tammy L

    2004-06-15

    Humic acids (HAs) form coatings on clays and minerals that can play an important role in nutrient and contaminant migration in soil and water. Humic acid-clay mineral interactions are known to be affected by pH and ionic strength, but little attention has been paid to the effects of temperature. In this paper we report the stoichiometry and thermodynamics of interactions of aqueous HAs (isolated from two peats, two soils and a marine alga with a method that removes lipids) with kaolinite clay, Al2Si2O5(OH)4, at seven temperatures from 5.0 to 35.0 degrees C in 0.05 M NaCl at pH 3.5. All the sorption isotherms exhibit consecutive steps ascribed to HA monolayer and bilayer formation, respectively. Site capacity comparisons suggest different HA molecular conformations on kaolinite. Linearly correlated enthalpy and entropy changes for HA sorption point to the importance of hydration and dehydration in the sorption mechanism. PMID:15260333

  4. The ectomycorrhizal community of conifer stands on peat soils 12years after fertilization with wood ash.

    PubMed

    Klavina, Darta; Pennanen, Taina; Gaitnieks, Talis; Velmala, Sannakajsa; Lazdins, Andis; Lazdina, Dagnija; Menkis, Audrius

    2016-02-01

    We studied long-term effects of fertilization with wood ash on biomass, vitality and mycorrhizal colonization of fine roots in three conifer forest stands growing in Vacciniosa turf. mel. (V), Myrtillosa turf. mel. (M) and Myrtillosa turf. mel./Caricoso-phragmitosa (MC) forest types on peat soils. Fertilization trials amounting 5kg/m(2) of wood ash were established 12years prior to this study. A total of 63 soil samples with roots were collected and analysed. Ectomycorrhizal (ECM) fungi in roots were identified by morphotyping and sequencing of the fungal internal transcribed spacer (ITS) region. In all forest types, fine root biomass was higher in fertilized plots than in control plots. In M forest type, proportion of living fine roots was greater in fertilized plots than in control plots, while in V and MC, the result was opposite. Fifty ECM species were identified, of which eight were common to both fertilized and control plots. Species richness and Shannon diversity index were generally higher in fertilized plots than in control plots. The most common species in fertilized plots were Amphinema byssoides (17.8%) and Tuber cf. anniae (12.2%), while in control plots, it was Tylospora asterophora (18.5%) and Lactarius tabidus (20.3%). Our results showed that forest fertilization with wood ash has long-lasting effect on diversity and composition of ECM fungal communities. PMID:26208815

  5. A coupled molecular and field-based approach to study microbial controls on methane flux in upland soils

    NASA Astrophysics Data System (ADS)

    Judd, C. R.; von Fischer, J. C.; Fierer, N.

    2007-12-01

    Predicting the responses of ecosystems to global change depends, in part, on understanding how soil microbial communities respond to external controls. To address this question, we are studying a relatively simple biogeochemical process: methane consumption in upland (i.e., well-drained, oxic) soils. In this process, methane molecules diffuse from the atmosphere into the soil, where they are consumed by methanotrophic bacteria. Because of the simplicity of this process, we have been able to develop a reaction-diffusion model that allows us to directly quantify methanotroph activity in situ from chamber-based measures of flux and diffusivity. Moreover, because the bacteria that oxidize methane come from a phylogenetically cohesive group, we can use molecular tools to quantify the size of methanotroph community and determine its species composition. Our application of these approaches on the Shortgrass Steppe Long-Term Ecological Research (SGS LTER) site in northeastern Colorado has revealed strong temporal and spatial patterns in methane uptake rates that are driven primarily by methanotroph activity, and very little by soil diffusivity. The temporal patterns in methanotroph activity follow seasonal changes in soil temperature and water content, with sharp reductions in activity associated with hot, dry conditions. Spatial patterns in activity follow differences in soil texture, with sandier soils expressing a greater range of methanotroph activity than clay soils. Although methanotroph abundances did not vary across soil types, the phylogenetic structure of the methanotroph communities differed significantly between clay and sand soil types. In addition, we found that the majority of methanotrophs were not the usual Type I or Type II, but instead were of the JR2 and JR3 types previously found only in a dry California grassland by Horz et al. AEM (2005). Together, these observations suggest that the species composition of methanotroph communities reflects changes in the physical environment. Given the potential for specialization among methanotrophs (e.g., for desiccation tolerance, or for methane affinity), we anticipate that the specific phylogenetic and physiological characteristics of methane oxidizer communities will modulate the responses of upland methane fluxes to climate change.

  6. Influence of oil and stratal water contamination on the ash composition of oligotrophic peat soils in the oil-production area (the Ob' region)

    NASA Astrophysics Data System (ADS)

    Vodyanitskii, Yu. N.; Avetov, N. A.; Savichev, A. T.; Trofimov, S. Ya.; Shishkonakova, E. A.

    2013-10-01

    The mineral contamination of peat soils in the oil-production area differs considerably in the places of oil or stratal water spills. The time elapsed since the spill occurred is also an important factor of the changes in the chemical composition of the peat ash. The ash content rises drastically in the oil-contaminated peat, and the peat ash becomes rich in heavy metals (Mn, Ni, and Sr) and lanthanides (La and Ce). The content of K and Fe decreases, and that of P, S, Mg, Ca, Ni, and Pb increases with time at the site of old oil contamination. In the course of the self-rehabilitation of oil-contaminated peat, the content of Cl decreases more intensely than that of the heavier halogen Br. The ash content rises to a lesser extent in the peat contaminated with stratal water. The ash of the salinized peat is enriched in heavy alkaline-earth elements, i.e., Ba and Sr. Although most of the elements are leached with time, the content of Ba and Sr still remains 4-6 times higher than the background one even after long-term (more than 10 years) leaching. The concentrations of halogens rise considerably in the salinized peat, that of Cl in the peat ash decreases by 10 times, and the content of Ba virtually remains the same.

  7. Identification of the Functionally Active Methanotroph Population in a Peat Soil Microcosm by Stable-Isotope Probing

    PubMed Central

    Morris, Samantha A.; Radajewski, Stefan; Willison, Toby W.; Murrell, J. Colin

    2002-01-01

    The active population of low-affinity methanotrophs in a peat soil microcosm was characterized by stable-isotope probing. Heavy 13C-labeled DNA, produced after microbial growth on 13CH4, was separated from naturally abundant 12C-DNA by cesium chloride density gradient centrifugation and used as a template for the PCR. Amplification products of 16S rRNA genes and pmoA, mxaF, and mmoX, which encode key enzymes in the CH4 oxidation pathway, were analyzed. Sequences related to extant type I and type II methanotrophs were identified, indicating that these methanotrophs were active in peat exposed to 8% (vol/vol) CH4. The 13C-DNA libraries also contained clones that were related to ?-subclass Proteobacteria, suggesting that novel groups of bacteria may also be involved in CH4 cycling in this soil. PMID:11872500

  8. Restoration of Upland Hardwood Tree Species on the Formerly Cultivated Soils in the Coastal Plain of South Carolina

    SciTech Connect

    Jones, R.H.; Waldrop, T.A.

    2001-08-03

    The authors studied various approaches to restore upland hardwood species to formerly cultivated soils at the SRS. Studies with direct seedling were largely a failure and resulted in very low rates of establishment. Failure was a result of predation and drought. Growth and survival of planted oaks, dogwood and pine did not vary between hardwood overstory and pine overstory conditions. Soil trenching in a forty year old loblolly stand demonstrated dramatic increases in growth of planted oaks and dogwood. When compared, survival is similar if not slightly better when seedlings are planted in the understory of canopies vs. clearcuts. However, growth is better in recent clearcuts for dogwood and white oaks. Hickory does better underplanted.

  9. Coevolution of topography, soils, and vegetation in upland landscapes: Using cinder cones to elucidate ecohydrogeomorphic feedback mechanisms

    NASA Astrophysics Data System (ADS)

    McGuire, L.; Pelletier, J. D.; Rasmussen, C.

    2013-12-01

    The study of landscape evolution in upland environments requires analysis of complex interactions among topography, soil development, and vegetation cover under changing climatic conditions. Earth surface scientists lack a comprehensive understanding of these interactions in part due to their interdisciplinary nature, our limited ability to reconstruct the progression of landscape states through time, and the limited spatially-distributed data available for paleoclimate conditions. In this study, we investigate the interactions and feedbacks among topography, soil development, and vegetation cover in upland environments using remote sensing, geochemistry, and numerical modeling. We focus on quantifying the evolution of late Quaternary cinder cones within several volcanic fields, spanning a range of climates, as a function of age and microclimate, which varies with elevation and slope aspect. Cinder cones are excellent natural laboratories for studying the evolution of upland landscapes because they begin their evolution at a known time in the past (i.e. many cinder cones have been radiometrically dated) and because they often have unusually uniform initial conditions (i.e. they form close to the angle of repose and are comprised of well-sorted volcaniclastic parent materials). As such, cinder cones of different ages with similar size and climatic history can provide an approximate time progression illustrating how a dated hillslope has evolved over geologic time scales. Data suggest that rates of soil development and fluvial erosion are low on younger cones, which have surfaces consisting mostly of permeable cinders, but increase significantly after eolian deposits reduce the permeability of the cone surface. Further, data demonstrate that microclimatic differences between north and south facing slopes lead to systematic variations in biomass. Additionally, north-facing slopes on cinder cones are found to be steeper than corresponding south-facing slopes. The observed asymmetries in hillslope morphology are not present initially, but appear to develop over time as a result of differences in post-emplacement processes that may be attributed to aspect-induced microclimatic effects on long-term sediment transport rates. Results provide additional constraints on the timing and magnitude of feedback mechanisms among topography, biomass, and soil development as well as improve our understanding of cinder cone evolution within different climates.

  10. Uncertainties in peat volume and soil carbon estimated using ground penetrating radar and probing

    SciTech Connect

    Parsekian, Andrew D.; Slater, Lee; Ntarlagiannis, Dimitrios; Nolan, James; Sebestyen, Stephen D; Kolka, Randall K; Hanson, Paul J

    2012-01-01

    We evaluate the uncertainty in calculations of peat basin volume using high-resolution data . to resolve the three-dimensional structure of a peat basin using both direct (push probes) and indirect geophysical (ground penetrating radar) measurements. We compared volumetric estimates from both approaches with values from literature. We identified subsurface features that can introduce uncertainties into direct peat thickness measurements including the presence of woody peat and soft clay or gyttja. We demonstrate that a simple geophysical technique that is easily scalable to larger peatlands can be used to rapidly and cost effectively obtain more accurate and less uncertain estimates of peat basin volumes critical to improving understanding of the total terrestrial carbon pool in peatlands.

  11. Mechanisms regulating bioavailability of phenanthrene sorbed on a peat soil-origin humic substance.

    PubMed

    Yang, Yu; Shu, Liang; Wang, Xilong; Xing, Baoshan; Tao, Shu

    2012-07-01

    The organic matter-mineral complex plays an important role in regulating the fate of hydrophobic organic compounds (HOCs) in the environment. In the present study, the authors investigated the microbial bioavailability of phenanthrene (PHE) sorbed on the original and demineralized humic acids (HAs) and humin (HM) that were sequentially extracted from a peat soil. Demineralization treatment dramatically decreased the 720-h mineralized percentage of HM-sorbed PHE from 42.5 2.6% to 3.4 1.3%, whereas the influence of this treatment on the biodegradability of HA-associated PHE was much lower. Degradation kinetics of HA- and HM-sorbed PHE showed that its initial degradation rate was negatively correlated with the aromatic carbon content of humic substances (p<0.05). This was attributed to the strong interactions between PHE and the aromatic components of humic substances, which hampered its release and subsequent biodegradation. The 720-h mineralized percentage of PHE was inversely correlated with the estimated thickness of the organic matter layer at the surfaces of HAs and HMs. Therefore, in a relatively long term, diffusion of PHE within the organic matter layer could be an important factor that may limit the bioavailability of PHE to bacteria. Results of the present study highlight the molecular-scaled mechanisms governing bioavailability of PHE sorbed on humic substances. PMID:22511468

  12. Biogeochemistry of carbon and related major and trace elements in peat bog soils of the middle taiga of Western Siberia (Russia).

    NASA Astrophysics Data System (ADS)

    Stepanova, V. A.; Mironycheva-Tokareva, N. P.; Pokrovsky, O. S.

    2012-04-01

    Global climate changes impact the status of wetland ecosystems shifting the balances of the carbon, macro-, and microelements cycles. This study aims to establish the features of accumulation and distribution of major- and trace elements in the organic layer of peat bog soils, belonging to different ecosystems of the oligotrophic bog complex located in the middle taiga of Western Siberia (Khanty-Mansiysk region, Russia). Key areas which are selected for this study include the following bog conjugate elementary ecosystems: higher ryam, lower ryam, ridge-hollow complex, and oligotrophic poor fen as characterized previously [1]. We have sampled various peat types along the entire length of the soil column (every 10 cm down to 3 m). Peat samples were analyzed for a wide range of macro- and microelements using an ICP-MS technique following full acid digestion in a microwave oven. These measurements allowed quantitative estimates of major- and trace elements in the peat deposits within the whole bog complex and individual elementary landscapes. Based on the data obtained, the lateral and radial geochemical structures of the bog landscapes were determined and clarified for the first time for middle taiga of the West Siberian plain. The similar regime of mineral nutrition during the complete bog landscape formation was detected for the peat deposits based on the measurements of some major- and trace elements (Ca, Fe, Mg, etc.). The vertical distribution of some major and some trace elements along the profile of peat column is rather uniform with relatively strong increase in the bottom organic layers. This strongly suggests the similarity of the processes of element accumulation in the peat and relatively weak post depositional redistribution of elements within the peat soil profile. Overall, obtained corroborate the existing view on chemical composition of peats being determined by botanical peat's components (which forms this peat deposit), atmospheric precipitation, position of ecosystems in the landscape (lateral migration) and types of bedrocks [2]. The results allow better understanding of the coupling between biogeochemical cycles of carbon and major and trace elements in peat soils in order to predict the future changes in both concentrations and stocks of chemical elements in the Western Siberia peat bog systems under climate warming.

  13. Effect of Long-Term Paddy-Upland Yearly Rotations on Rice (Oryza sativa) Yield, Soil Properties, and Bacteria Community Diversity

    PubMed Central

    Chen, Song; Zheng, Xi; Wang, Dangying; Chen, Liping; Xu, Chunmei; Zhang, Xiufu

    2012-01-01

    A 10-year-long field trial (between 2001 and 2010) was conducted to investigate the effect of paddy-upland rotation on rice yield, soil properties, and bacteria community diversity. Six types of paddy-upland crop rotations were evaluated: rice-fallow (control; CK), rice-rye grass (RR), rice-potato with rice straw mulches (RP), rice-rapeseed with straw incorporated into soil at flowering (ROF), rice-rapeseed incorporated in soil after harvest (ROM), and rice-Chinese milk vetch (RC). Analysis of terminal restriction fragment length polymorphism (T-RFLP) was used to determine microbial diversity among rotations. Rice yield increased for upland crops planted during the winter. RC had the highest average yield of 7.74?t/ha, followed by RR, RP, ROM, and ROF. Soil quality differences among rotations were found. RC and RP improved the soil mean weight diameter (MWD), which suggested that rice rotated with milk vetch and potato might improve the paddy soil structure. Improved total nitrogen (TN) and soil organic matter (SOM) were also found in RC and RP. The positive relationship between yield and TN/SOM might provide evidence for the effect of RC rotation on rice yield. A strong time dependency of soil bacterial community diversity was also found. PMID:22919301

  14. Effect of soil texture, tailwater height, and pore-water pressure on the morphodynamics of migrating headcuts in upland concentrated flows

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Rill and gully erosion in upland and agricultural areas can result in significant soil degradation worldwide, and headcuts are the primary mechanism by which this landscape dissection occurs. Experiments were conducted to further examine the morphodynamic behavior of actively migrating headcuts in u...

  15. Effect of converting wetland forest to sago palm plantations on methane gas flux and organic carbon dynamics in tropical peat soil

    NASA Astrophysics Data System (ADS)

    Inubushi, K.; Hadi, A.; Okazaki, M.; Yonebayashi, K.

    1998-10-01

    The effect of changing wetland forest to sago palm plantations on methane gas flux and organic carbon dynamics in tropical peat soil was studied in the field and the laboratory using soil samples from the Peat Research Station, Sarawak, Malaysia. A small amount of methane was released from the soil surface of both the forest and plantation field, with no significant difference between the two sites (11+/-061 and 139+/-082 mg CH4 m-2 hr-1, respectively); thus, the amount of methane emission from the total area of tropical peat soil was estimated, preliminarily, as 243 Tg yr-1, contributing 045% of the total global methane emission and 21% of methane emissions from global natural wetland. However, large amounts of methane were accumulated in the deeper soil layers. Sago palm contained much less carbon as biomass, but lost more as the carbon dissolved in groundwater. Laboratory experiments showed that incorporation of rice straw into tropical peat soil increased methane formation significantly. Conversely, ammonium sulfate suppressed methane formation in tropical peat soil.

  16. Exploring the potential of the permanganate oxidation method as a tool to monitor soil quality in agricultural upland systems of Southeast Asia

    NASA Astrophysics Data System (ADS)

    Hepp, Catherine M.; Bruun, Thilde Bech; de Neergaard, Andreas

    2014-05-01

    The transition to more intensified upland systems is having an impact on the soil quality, defined as the ability of a soil to both provide and maintain essential services to an ecosystem. As many tropical upland soils are inherently low in quality, it is essential that impacts be monitored. Soil quality is assessed by using a combination of parameters that serve as indicators and cover the soil chemical, biological and physical properties. An ideal indicator should be sensitive to changes in the environment and management practices and should be widely accessible, meaning low resource requirement (i.e. time and equipment). Total organic carbon (TOC) content is a commonly used indicator of soil quality as it is linked to many soil functions and processes; however analysis is costly and requires access to advanced instrumental facilities, rendering it unsuited for many developing countries. An alternative indicator is the soil fraction dominated by easily decomposable carbon; this may be measured by treating soil samples with 0.2M potassium permanganate (KMnO4), an oxidizing agent which is thought to mimic the enzymes released by the soil microbial community. The advantage of this method is that it is accessible: it is fast, requires little resource input and is field appropriate. There is no consensus however as to which soil carbon fraction the method targets. Furthermore Skjemstad et al. (2006) has indicated that KMnO4 may oxidise charcoal, a component of the non-labile carbon pool; this has implications for the suitability of the method when used for soils of shifting cultivation systems. The purpose of this study was to investigate the potential of permanganate oxidizable carbon (Pox C) as a reliable indicator of soil quality in agricultural upland systems in Northern Lao PDR. Focus was placed on the relations between Pox C and other soil quality parameters (bulk density, pH, CEC, TOC, total N, exchangeable K, plant available P) and upland rice yields. The ability of KMnO4 to oxidize charcoal was also a focus however, as the study is still in its initial stage, no results can be discussed. Volumetric soil samples (at the surface and at 10 cm) and upland rice yield measurements were taken from three fields with three plots that were previously left fallow for five years (n=9; soil n=81). Pearson's Correlation test and Stepwise Regression analysis was done using SPSS v 16.0 for Windows. Results show that Pox C is significantly correlated to the measured soil parameters in a manner similar to TOC. Both are positively correlated to the soil nutrients: Total N %, P Avail and K Exch; Pox C however had a stronger correlation to K Exch than TOC. This affirms the important role of Pox C in soil processes in the biological, chemical and physical spheres. Furthermore, the regression analysis identified Pox C as an influencing factor for the variations seen in upland rice yields. It is concluded that Pox C is a suitable indicator for soil quality and may be useful in monitoring changes in the soil quality of agricultural upland systems.

  17. Stable Isotope Probing of Peat and Forest Floor Amendments

    NASA Astrophysics Data System (ADS)

    Quideau, Sylvie; Béasse, Mark

    2013-04-01

    In Alberta, Canada, land reclamation efforts utilize peat as an organic amendment to help reclaim decommissioned oil sands mine sites to upland boreal forests. This study investigates the rhizosphere microbial communities of two pioneer species, aspen (Populus tremuloides Michx.), a species not known for strong associations with the soil microbial community, and alder (Alnus crispa Ait.), a species well known for mutualism with actinomycetes. Specifically, the objective was to determine how different organic amendments (peat versus forest floor) influenced the rhizosphere microbial communities and how this could be linked to plant growth. Seedlings were grown for 20 weeks in forest floor material, peat, and a combination of both. They were pulse labelled with 13CO2 (g) and subsequently harvested for plant growth measurements. While analysis of plant growth attributes did not indicate any effect of the organic amendment on aspen growth, alder reported significantly less growth in peat treatments. The rhizosphere soils were extracted for compound-specific analysis of δ13C in microbial phospholipid fatty acids. Stable isotope probing showed greater carbon flow between trees and their rhizosphere communities when seedlings were grown in forest floor material.

  18. Soil evolution and climate dynamics in dry steppes of the Privolzhskaya Upland during the last 3500 years

    NASA Astrophysics Data System (ADS)

    Demkin, V. A.; Demkina, T. S.; Khomutova, T. E.; El'tsov, M. V.

    2012-12-01

    The investigation of paleosols of different ages buried under archaeological monuments of the Bronze (16th-15th centuries BC), Early Iron (2nd-3rd centuries AD), and Medieval (14th century AD) ages demonstrated that the evolution of chestnut soils and solonetzes in the dry steppes of the southern part of the Privolzhskaya Upland during the past 3500 years manifested itself at the level of the genus and species characteristics of the soils, such as the degree of the solonetzicity, the humus content, and the content and composition of the soluble salts. The revealed regularities of the variations of the morphological, chemical, and microbiological soil properties in time allowed reconstructing the secular dynamics of the climatic humidity in the region. It was found that the humidization of the climate with a decrease in the degree of the climatic continentality took place in the middle of the second millennium BC. The Late Sarmatian Time (2nd-3rd centuries AD) was characterized by arid climatic conditions, whereas the Golden Horde time (13th-14th centuries AD) was marked by the general humidization of the climate. A gradual aridization of the climate began in the second half of the 14th century and continued in the 15th century AD.

  19. Effects of soils and grazing on breeding birds of uncultivated upland grasslands of the Northern Great Plains

    USGS Publications Warehouse

    Kantrud, H.A.; Kologiski, R.L.

    1982-01-01

    The principal use of uncultivated upland grasslands in the northern Great Plains is for livestock production. However, on lands set aside for wildlife or for scientific or recreational use, grazing by livestock may be used as a management measure to enhance populations of game species or to create conditions that increase the diversity of plant or animal species. To determine the effects of grazing on the avifauna of various types of Great Plains grasslands, we conducted bird censuses and plant surveys during 1974-78 on 615 plots of lightly, moderately, or heavily grazed native rangeland.Numbers of horned lark (Eremophila alpestris), western meadowlark (Sturnella neglecta), lark bunting (Calamospiza melanocorys), and chestnut-collared longspur (Calcarius ornatus) accounted for 65-75% of the total bird population, regardless of grazing intensity. For the entire area sampled (600,000 km2), horned lark, western meadowlark, and chestnut-collared longspur were the dominant birds. Major differences in composition of the dominant species and species richness occurred among the major soils. Increased mean annual soil temperature seemingly had a greater negative influence on avian species richness than did decreased soil moisture or organic matter content. Differences in total bird density were not significant among soils and among grazing intensities within most soils. For the area as a whole, light or moderate grazing resulted in increased species richness. Of the 29 species studied, 2 responded significantly to grazing for the area as a whole and 6 others to grazing on the soil in which peak densities occurred. Response of several other species to grazing effects evidently varied among strata.A list of plants with mean cover values of more than 1% in any of the 18 combinations of soils and grazing intensities contained less than 25 species, attesting to the relative simplicity of the grassland vegetation in the northern Great Plains. Agropyron spp. and Bouteloua gracilis were the dominant plants that provided greater than average cover on the best habitat for the most bird species. Optimum habitat for each bird species is given in terms of grazing, soils, and dominant plant species. Increased soil temperature probably had a negative effect on plant species richness, especially among soils with a high organic matter content that supported perennial grasses and other mesophytes.

  20. Mercury in mushrooms and soil from the Wieluńska Upland in south-central Poland.

    PubMed

    Falandysz, Jerzy; Bielawski, Leszek; Kawano, Masabide; Brzostowski, Andrzej; Chudzyński, Krzysztof

    2002-09-01

    Concentrations of mercury were determined in the fruiting bodies of 15 species of higher mushrooms and underlying soil substrate collected from Wieluńska Upland in northern part of Sandomierska Valley in south-central Poland in 1995. A total of 197 samples of caps, 197 stalks, 30 whole fruiting bodies and 227 soil (0-10 cm layer) were analyzed. Mean mercury concentrations in soil substrate corresponding to 15 mushroom species were between 28 +/- 17 and 85 +/- 62 ng/g dry matter (total range between 3.0-190 ng/g). The average cap to stalk concentration quotients of Hg were around 2 (range between 1.1 +/- 1.1 and 2.8 +/- 1.4). However, this quotient in Larch bolete (Suillus grevillei) was 4.4 +/- 6.3. Concentrations of Hg varied depending on the mushroom species. Parasol Mushroom (Macrolepiota procera) and Horse mushroom (Agaricus arvensis) contained the greatest mean mercury concentrations both in caps (between 4500 +/- 1700 and 4400 +/- 2400 ng/g dry matter) and stalks (between 2800 +/- 1300 and 3000 +/- 2000 ng/g dry matter). Both the Parasol Mushroom and Horse mushroom were characterised also by a greater potential to bioconcentrate mercury from soils as evidenced by great bioconcentration factors (BCFs), which were between 170 +/- 160 and 130 +/- 120 for caps, and 110 +/- 97 and 89 +/- 92 for stalks. Mercury concentrations in caps and stalks of False death cap (Amanita citrina) increased (p < 0.05) with increasing soil mercury contents. An opposite trend was observed for Quéleta brittle gills (Russula queleti), Grat knight-cap (Tricholoma terreum), Fly agaric (Amanita muscaria), Common scaber stalk (Leccinum scabrum) and Slippery jack (Suillus luteus). PMID:12369635

  1. Catchment disturbance and stream metabolism: Patterns in ecosystem respiration and gross primary production along a gradient of upland soil and vegetation disturbance

    USGS Publications Warehouse

    Houser, J.N.; Mulholland, P.J.; Maloney, K.O.

    2005-01-01

    Catchment characteristics determine the inputs of sediments and nutrients to streams. As a result, natural or anthropogenic disturbance of upland soil and vegetation can affect instream processes. The Fort Benning Military Installation (near Columbus, Georgia) exhibits a wide range of upland disturbance levels because of spatial variability in the intensity of military training. This gradient of disturbance was used to investigate the effect of upland soil and vegetation disturbance on rates of stream metabolism (ecosystem respiration rate [ER] and gross primary production rate [GPP]). Stream metabolism was measured using an open-system, single-station approach. All streams were net heterotrophic during all seasons. ER was highest in winter and spring and lowest in summer and autumn. ER was negatively correlated with catchment disturbance level in winter, spring, and summer, but not in autumn. ER was positively correlated with abundance of coarse woody debris, but not significantly related to % benthic organic matter. GPP was low in all streams and generally not significantly correlated with disturbance level. Our results suggest that the generally intact riparian zones of these streams were not sufficient to protect them from the effect of upland disturbance, and they emphasize the role of the entire catchment in determining stream structure and function. ?? 2005 by The North American Benthological Society.

  2. Simulating the effect of land use and climate change on upland soil carbon stock of Wales using ECOSSE

    NASA Astrophysics Data System (ADS)

    Rani Nayak, Dali; Gottschalk, Pia; Evans, Chris; Smith, Pete; Smith, Jo

    2010-05-01

    Within Wales soils hold between 400-500 MtC, over half of this carbon is stored in organic and organo-mineral soil which cover less than 20% of the land area of Wales. It has been predicted that climate change will increasingly have an impact on the C stock of soils in Wales. Higher temperatures will increase the rate of decomposition of organic matter, leading to increased C losses. However increased net primary production (NPP), leading to increased inputs of organic matter, may offset this. Land use plays a major role in determining the level of soil C and the direction of change in status (soil as a source or sink). We present here an assessment of the effect of land use change and climate change on the upland soil carbon stock of Wales in 3 different catchments i.e. Migneint, Plynlimon and Pontbren using a process-based model of soil carbon and nitrogen dynamics, ECOSSE. The uncertainties introduced in the simulations by using only the data available at national scale are determined. The ECOSSE model (1,2) has been developed to simulate greenhouse gas emissions from both organic and mineral soils. ECOSSE was derived from RothC (3) and SUNDIAL (4,5) and predicts the impacts of changes in land use and climate on emissions and soil carbon stock. Simulated changes in soil C are dependent on the type of land use change, the soil type where the land use change is occurring, and the C content of soil under the initial and final land uses. At Migneint and Plynlimon, the major part of the losses occurs due to the conversion of semi-natural land to grassland. Reducing the land use change from semi-natural to grassland is the main measure needed to mitigate losses of soil C. At Pontbren, the model predicts a net gain in soil C with the predicted land use change, so there is no need to mitigate. Simulations of future changes in soil C to 2050 showed very small changes in soil C due to climate compared to changes due to land use change. At the selected catchments, changes in soil C due to the impacts of land use change were predicted to be up to 1000 times greater than the changes predicted due to climate change. This is encouraging, as it illustrates the great potential for C losses due to climate change to be mitigated by changing land use. 1. Smith P, et al 2007. SEERAD Report. ISBN 978 0 7559 1498 2. 166pp. 2. Smith JU, et al 2009. RERAD Report. In press. 3. Coleman K & Jenkinson DS 1996. In: Evaluation of Soil Organic Matter Models Using Existing, Long-Term Datasets, NATO ASI Series I, Vol.38 (eds Powlson DS, Smith P, Smith JU), pp. 237-246. Springer-Verlag, Heidelberg, Germany. 4. Bradbury NJ, et al 1993. Journal of Agricultural Science, Cambridge 121, 363-379. 5. Smith JU, et al 1996. Agronomy Journal 88, 38-42.

  3. Comparing terrestrial laser scanning with ground and UAV-based imaging for national-level assessment of upland soil erosion

    NASA Astrophysics Data System (ADS)

    McShane, Gareth; Farrow, Luke; Morgan, David; Glendell, Miriam; James, Mike; Quinton, John; Evans, Martin; Anderson, Karen; Rawlins, Barry; Quine, Timothy; Debell, Leon; Benaud, Pia; Jones, Lee; Kirkham, Matthew; Lark, Murray; Rickson, Jane; Brazier, Richard

    2015-04-01

    Quantifying soil loss through erosion processes at a high resolution can be a time consuming and costly undertaking. In this pilot study 'a cost effective framework for monitoring soil erosion in England and Wales', funded by the UK Department for Environment, Food and Rural Affairs (Defra), we compare methods for collecting suitable topographic measurements via remote sensing. The aim is to enable efficient but detailed site-scale studies of erosion forms in inaccessible UK upland environments, to quantify dynamic processes, such as erosion and mass movement. The techniques assessed are terrestrial laser scanning (TLS), and unmanned aerial vehicle (UAV) photography and ground-based photography, both processed using structure-from-motion (SfM) 3D reconstruction software. Compared to other established techniques, such as expensive TLS, SfM offers a potentially low-cost alternative for the reconstruction of 3D high-resolution micro-topographic models from photographs taken with consumer grade cameras. However, whilst an increasing number of research papers examine the relative merits of these novel versus more established survey techniques, no study to date has compared both ground-based and aerial SfM photogrammetry with TLS scanning across a range of scales (from m2 to 16ha). The evaluation of these novel low cost techniques is particularly relevant in upland landscapes, where the remoteness and inaccessibility of field sites may render some of the more established survey techniques impractical. Volumetric estimates of soil loss are quantified using the digital surface models (DSMs) derived from the data from each technique and subtracted from a modelled pre-erosion surface. The results from each technique are compared. The UAV was able to capture information over a wide area, a range of altitudes and angles over the study area. Combined with automated SfM-based processing, this technique was able to produce rapid orthophotos to support ground-based data acquisition, as well as a DSM for volume loss measurement in larger features. However, the DSM of erosion features lacked the detail of those captured using the ground-based methods. Terrestrial laser scanning provided detailed, accurate, high density measurements of the ground surface over long (100s m) distances, but size and weight of the instrument made it difficult to use in mountainous environments. In addition, deriving a reliable bare-earth digital terrain model (DTM) from TLS was at times problematic due to the presence of tall shrubby vegetation. Ground-based photography produced comparable data sets to terrestrial laser scanning and was the most useful for characterising small and difficult to view features. The relative advantages, limitations and cost-effectiveness of each approach at 5 upland sites across the UK are discussed.

  4. PHYSICAL AND ANALYTICAL MODELING OF UPLAND SOIL EROSION DUE TO HEADCUT MIGRATION

    Technology Transfer Automated Retrieval System (TEKTRAN)

    On hillslopes and agricultural fields, discrete areas of intense, localized soil erosion commonly take place in the form of migrating headcuts. These erosional features significantly increase soil loss and landscape degradation, yet the unsteady, transient, and migratory habits of headcuts complica...

  5. Inorganic and enzymatically hydrolyzable organic phosphorus of Alabama Decatur silt loam soils cropped with upland cotton

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Alabama is one of top cotton production states in the USA. It is believed that management practices would affect the distribution and fate of phosphorus (P) forms in these cotton soils. In this study, we assessed the forms and lability P in the Alabama Decatur silt loam cotton soils, and evaluated t...

  6. SOIL AMENDMENT WITH DIFFERENT PEAT MOSSES AFFECTS VA MYCORRHIZAE ON ONION

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Formation of VA mycorrhizae in soilless potting mixes that usually contain some proportion of peat moss has been inhibited in many cases. The cause o the inhibition has been reported to be high phosphorus (P) content in the media that suppresses spread of the fungal symbiont in the root tissue. How...

  7. 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 nodules. While these important chemical reactions have taken place silently and imperceptibly over millenia acrossthe Earth wherever climate and water allow bogs to form, at the same time, peat bogs represent an important component of the biosphere and provide a home to many unique plants and animals, thereby contributing to the vast biodiversity found on Earth.

  8. Peat Processing

    NASA Technical Reports Server (NTRS)

    1986-01-01

    Humics, Inc. already had patented their process for separating wet peat into components and processing it when they consulted NERAC regarding possible applications. The NERAC search revealed numerous uses for humic acid extracted from peat. The product improves seed germination, stimulates root development, and improves crop yields. There are also potential applications in sewage disposal and horticultural peat, etc.

  9. Soil Greenhouse Gas Emissions across a Riparian-Upland Transect: How Will Soils Respond to Anticipated Changes in Rainfall Magnitude and Frequency?

    NASA Astrophysics Data System (ADS)

    Weiglein, T.; Scott, D.; Strahm, B. D.

    2014-12-01

    Current global climate models predict climate change caused by anthropogenic greenhouse gas emissions will result in altered precipitation regimes by the end of the 21st century. Although there is still uncertainty regarding how mean annual rainfall will change in the mid-Atlantic region of the U.S., it is predicted that there will be larger rainfall events followed by extended dry periods. How this will affect greenhouse gas emissions across the landscape remains unclear. Here, we investigate the response of CO2, CH4, and N2O emissions from soil cores taken from a riparian-upland transect in southwest Virginia to changes in simulated rainfall magnitude and frequency. A preliminary experiment was conducted in early spring 2014 using soil cores collected in a riparian wetland in Virginia Tech's StREAM Lab. These cores were divided into three different treatment groups. Each group received the same total amount of water, but the magnitude and frequency of the application of water was altered to simulate a single large storm event, three medium storm events, or seven small storm events. Concentrations of CO2, CH4, and N2O in the chamber headspace were measured with a cavity ring-down spectrometer and used to calculate fluxes from the soil cores. Our preliminary results suggest that larger storm events result in greater temporary suppression of CO2 emissions, and higher temporal resolution is needed to fully characterize the response of N2O emissions to storm events. In late summer 2014, additional soil cores will be taken from three different zones along a riparian-upland transect, divided into treatment groups, and subjected to a refined version of the previously mentioned experimental procedures. Additionally, the soil from the three different zones will be characterized with chemical and physical methods. Statistical analyses will be performed to compare the effects of the different treatments and to determine the controls on the response of the soil cores. These results will provide insight into possible feedback loops that may exist between soil greenhouse gas emissions and altered precipitation regimes resulting from climate change.

  10. Soil archives of the Westerkoggepolder (West Friesland, North-Holland); relicts of a peat cover that disappeared by historical land management.

    NASA Astrophysics Data System (ADS)

    van Mourik, Jan; Ligtendag, Wim

    2013-04-01

    In a large part of the Westerkoggepolder the surficial Holocene peat deposit of several meters thickness disappeared in historical time due to historical land use. Drainage of the original histosols and crop production promoted bio-oxidation of the organic matrix and consequently lowering of the land surface. Relicts of this peat occur below old farm houses. In many soil sections a thin organic horizon is present in the stratigraphical position between older and younger clay deposits. This horizon can easily be interpreted as a relict of a peat deposit, truncated by marine transgression. In the Westerkoggepolder some lots show a typical micro relief. This is the result of local historical small scale peat digging and relief inversion afterwards. Land owners, responsible for this form of peat digging were obliged to fill the excavated trenches with material to restore the land surface. They used clay that they dredged up in the existing drain channels. That is also the reason that in the present landscape some of these channels are relatively broad. Due to relief inversion, these trenches are now visible as small ridges in the landscape. In the flat part of the landscape, a surficial clay layer covers the remnants of the excavated trenches. Pollen analysis indicates that the surficial clay layer must be interpreted as an eluvial alteration horizon. This surficial clay cover is a relict of the former peat bog.

  11. The sensitivity of peat soil and peatland vegetation to drought: release of dissolved organic carbon (DOC) on rewetting

    NASA Astrophysics Data System (ADS)

    Ritson, Jonathan; Graham, Nigel; Templeton, Michael; Freeman, Christopher; Clark, Joanna

    2015-04-01

    Organic rich peat soils are a major store of carbon worldwide. Their existence is predicated on high year-round water tables which create an anoxic environment, thus limiting decay, and also to the recalcitrance of plant litter (dead plant material) commonly found in peatland areas. Climate change threatens the stability of peat soils by altering the biogeochemical cycles which control plant decay, lowering water tables so that oxic degradation can occur and by changing habitat niches such that less recalcitrant species can thrive in peatlands. One of the major fluxes of carbon from peatlands is through dissolved organic carbon (DOC) in surface waters. As peatland areas in the UK are often used as source waters for drinking water supply this presents a problem to water utilities as DOC must be effectively removed to limit colour, odour and the formation of potentially carcinogenic by-products on disinfection. Changes in catchment vegetation may occur due to climate change, nutrient deposition and changing bioclimatic envelopes. How different peatland vegetation contribute to DOC flux and how this may change in the future is therefore of interest. A six week laboratory simulation was performed on typical peatland litter (Sphagnum spp., Calluna vulgaris, Molinea caerulea, Juncus effusus) and a peat soil collected from Exmoor National Park, UK. The simulation monitored DOC flux from the decaying litter/soil and considered the impact of different drought severities using the 50th, 25th, 10th and 5th percentiles of the mean July/August monthly rainfall for Exmoor. On rewetting following the drought, all sources produced significantly different amounts of DOC (Tukey HSD p<0.05) in the order Molinia>Juncus>Calluna>Sphagnum>peat. The source also had a significant (ANOVA p<0.001) effect on coagulation removal efficiency, a typical method of removing DOC during drinking water treatment, with Juncus DOC proving the easiest to remove whilst Sphagnum DOC was the most difficult. Sphagnum DOC had the lowest ratio of humic-like to protein-like fluorescence, which is indicative of DOC which is poorly removed by coagulation. An interactive effect was noted between DOC source and the drought treatment which was explored further using a one-way ANOVA with a Holm-Šidák correction. This suggested peat will produce significantly more DOC when affected by drought (p=0.010), possibly explained by increased oxygenation engaging the 'enzymatic latch' mechanism. A similar analysis was performed on the interaction between drought and DOC source for the specific UV absorbance at 254nm (SUVA) value (a measure of aromaticity). This suggested that Molinea caerulea produces DOC of significantly (p=0.001) higher aromaticity following periods of drought. Comparisons between drought and DOC source factors suggest the source in more important than climatic conditions of decay which is consistent with our previously published findings. These results have implications for marginal peatlands which may be at risk from increased water table drawdown in the future as climate changes and where Molinea caerulea, typically a fen species, is encroaching on bog communities.

  12. Soil Net Nitrification Rates and Exchangeable Calcium in Ten Small Upland Watersheds of the Northeastern USA

    NASA Astrophysics Data System (ADS)

    Ross, D.; Bailey, S.; Shanley, J.; Fredriksen, G.; Jamison, A.

    2004-05-01

    Possible links have been suggested between soil nitrification rates, soil calcium concentrations and tree species composition (e.g. sugar maple). We are measuring soil nitrification rates and stream nitrate export in ten watersheds in Vermont, New Hampshire and New York. These include relatively Ca-poor sites at Cone Pond NH and Ca-rich sites at Sleepers River, VT. Our objectives are to determine the relationship between nitrification rates and watershed characteristics (e.g. vegetation, soils, topography), and to explore the link between these rates and watershed nitrate export. Net nitrification rates are highly variable both within and among the eight sites and are related to the soil C/N ratio and vegetation characteristics at some, but not all, sites. Our preliminary results show distinct differences in exchangeable Ca concentrations among watersheds. Although some locations are enriched in Ca and high in sugar maple density, we have not found a good overall relationship between Ca and net nitrification rates. High rates can be found in Ca-enriched sites that are also relatively high in pH.

  13. Lead content and isotopic composition in submound and recent soils of the Volga Upland

    NASA Astrophysics Data System (ADS)

    Pampura, T. V.; Probst, A.; Ladonin, D. V.; Demkin, V. A.

    2013-11-01

    Literature data on the historical reconstructions of the atmospheric lead deposition in Europe and the isotopic composition of the ores that are potential sources of the anthropogenic lead in the atmospheric deposition in the lower Volga steppes during different time periods have been compiled. The effect of the increasing anthropogenic lead deposition recorded since the Bronze Age on the level of soil contamination has been investigated. For the first time paleosol buried under a burial mound of the Bronze Age has been used as a reference point to assess of the current contamination level. The contents and isotopic compositions of the mobile and total lead have been determined in submound paleosols of different ages and their recent remote and roadside analogues. An increase in the content and fraction of the mobile lead and a shift of its isotopic composition toward less radiogenic values (typical for lead from the recent anthropogenic sources) has been revealed when going from a Bronze-Age paleosol to a recent soil. In the Bronze-Age soil, the isotopic composition of the mobile lead is inherited from the parent rock to a greater extent than in the modern soils, where the lead is enriched with the less radiogenic component. The effect of the anthropogenic component is traced in the analysis of the mobile lead, but it is barely visible for the total lead. An exception is provided by the recent roadside soils characterized by increased contents and the significantly less radiogenic isotopic composition of the mobile and total lead.

  14. Sorption of selected organic compounds from water to a peat soil and its humic-acid and humin fractions: Potential sources of the sorption nonlinearity

    USGS Publications Warehouse

    Chiou, C.T.; Kile, D.E.; Rutherford, D.W.; Sheng, G.; Boyd, S.A.

    2000-01-01

    The sorption isotherms of ethylene dibromide (EDB), diuron (DUN), and 3,5-dichlorophenol (DCP) from water on the humic acid and humin fractions of a peat soil and on the humic-acid of a muck soil have been measured. The data were compared with those of the solutes with the whole peat from which the humic-acid (HA) and humin (HM) fractions were derived and on which the sorption of the solutes exhibited varying extents of nonlinear capacities at low relative concentrations (C(e)/S(w)). The HA fraction as prepared by the density-fractionated method is relatively pure and presumably free of high- surface-area carbonaceous material (HSACM) that is considered to be responsible for the observed nonlinear sorption for nonpolar solutes (e.g., EDB) on the peat; conversely, the base-insoluble HM fraction as prepared is presumed to be enriched with HSACM, as manifested by the greatly higher BET- (N2) surface area than that of the whole peat. The sorption of EDB on HA exhibits no visible nonlinear effect, whereas the sorption on HM shows an enhanced nonlinearity over that on the whole peat. The sorption of polar DUN and DCP on HA and HM display nonlinear effects comparable with those on the whole peat; the effects are much more significant than those with nonpolar EDB. These results conform to the hypothesis that adsorption onto a small amount of strongly adsorbing HSACM is largely responsible for the nonlinear sorption of nonpolar solutes on soils and that additional specific interactions with the active groups of soil organic matter are responsible for the generally higher nonlinear sorption of the polar solutes.

  15. Peat slides and rain fall intensities

    NASA Astrophysics Data System (ADS)

    Carroll, Roselyn; Long, Mike

    2010-05-01

    The objective of this work is to assess the reasons for peat bog slides in upland areas of Ireland and to provide tools for susceptibility assessment of future slides. A case study of a recent peat slide in Ireland will be presented in order to address these objectives. The slide occurred on the 23rd August 2009 north of Glencolmcille, Co. Denegal in an upland blanket bog. The interaction of groundwater, rainfall, and human activities in peat areas are all considered casual factors that impact on the stability of peat. An understanding of these factors combined with the shear strength of peat will help in assessing the risks of peat slope failures. Rainfall from previous years and at the time of the slide, peat shear strength and known human activities at the slide location will be assed and a description of the slide will be presented. Boylan et al. (2008) noted that the most commonly cited casual factor for peat slope failures was periods of incense or prolonged rainfall. Basic geotechnical properties of the peat sampled at different depths will be presented. A shear strength profile of peat at the location of the slide will be developed using direct simple shear (DSS) tests. The shear strength results from DSS tests will be implemented in a limit state slope stability model for the slide location so as to back calculate the existing slide and then could be used in a risk assessment of a peat slide. Boylan, N., Jennings, P. & Long, M. (2008) Peat slope failure in Ireland. Quarterly Journal of Engineering Geology and Hydrogeology, 41(1), 93-108.

  16. PHOSPHORUS COMPOSITION OF UPLAND SOILS POLLUTED BY LONG-TERM ATMOSPHERIC NITROGEN DEPOSITION

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Atmospheric N deposition can enhance biological P limitation in terrestrial ecosystems and increase the importance of organic P to plants and microorganisms. We used NaOH-EDTA extraction and phosphorus-31 NMR spectroscopy to determine the P composition of soils in the Upper Teesdale National Nature...

  17. Draft Genome Sequences of Two Antimicrobial-Producing Burkholderia sp. Strains, MSh1 and MSh2, Isolated from Malaysian Tropical Peat Swamp Forest Soil

    PubMed Central

    Aw, Yoong Kit; Gan, Han Ming; Yule, Catherine M.; Lee, Sui Mae

    2014-01-01

    We report the draft genome sequences of two antimicrobial-producing isolates, Burkholderia sp. strains MSh1 and MSh2, which were isolated from tropical peat swamp forest soil. Putative genes related to different antimicrobial production have been annotated in both genome sequences. PMID:25301661

  18. Draft Genome Sequences of Two Antimicrobial-Producing Burkholderia sp. Strains, MSh1 and MSh2, Isolated from Malaysian Tropical Peat Swamp Forest Soil.

    PubMed

    Ong, Kuan Shion; Aw, Yoong Kit; Gan, Han Ming; Yule, Catherine M; Lee, Sui Mae

    2014-01-01

    We report the draft genome sequences of two antimicrobial-producing isolates, Burkholderia sp. strains MSh1 and MSh2, which were isolated from tropical peat swamp forest soil. Putative genes related to different antimicrobial production have been annotated in both genome sequences. PMID:25301661

  19. Time-lapse ground penetrating radar (GPR) measurements for exploring biogenic gas distribution and releases from peat soils in the Florida Everglades

    NASA Astrophysics Data System (ADS)

    Wright, W. J.; Comas, X.; Berber, M.

    2013-12-01

    Peat soils are known to release significant amounts of methane (CH4) and carbon dioxide (CO2) to the atmosphere. However, uncertainties still remain regarding the spatio-temporal distribution of gas accumulations and the triggering mechanisms of gas releasing events. Furthermore, most peatland gas dynamics research has historically been focused on high latitude peatlands, while recent works have suggested that gas production rates from low-latitude peat soils may be higher than those from colder climates. Ground penetrating radar (GPR) is a geophysical tool that has successfully been used in the past to non-invasively investigate the release of biogenic gasses from peat soils. This study is conducted in the Loxahatchee Impoundment Landscape Assessment (LILA), a hydrologically controlled, landscape scale (30 HA) model of the Florida Everglades. Here, temporal and spatial heterogeneity of gas releases from peat soil at the plot scale (<100 m2) are shown using a time series of three-dimensional (3D) GPR measurements. GPR data are supported by direct gas flux measurements using flux chambers combined with time-lapse photography, and surface deformation measurements using terrestrial LiDAR scanning and differential leveling.

  20. Microbial activity and dissolved organic carbon production in drained and rewetted blanket peat

    NASA Astrophysics Data System (ADS)

    Wallage, Z. E.; Holden, J.; Jones, T.; McDonald, A. T.

    2009-04-01

    Heightened levels of degradation in response to environmental change have resulted in an increased loss of dissolved organic carbon (DOC) in the drainage waters of many peatland catchments across Europe and North America. One significant threat to peatland sustainability has been the installation of artificial drainage ditches, and although recent restoration schemes have pursued drain blocking as a possible strategy for reducing degradation and fluvial carbon losses, little is known about how such processes influence the intimate biological systems operating within these soils. This paper investigates how disturbance, in the form of drainage and drain blocking, influences the rate of microbial activity within a peat soil, and the subsequent impact this has on DOC production potential. Peat samples were extracted from three treatment sites (intact peat, drained peat and drain-blocked peat) in an upland blanket peat catchment in the UK. Microbial activity was measured via laboratory experimentation that incorporated the use of an INT-Formazan dehydrogenase enzyme assay to assess the level of electron transport system (ETS) activity occurring within each treatment. Drainage significantly lowered the height of the water table relative to the intact peat, whilst drain blocking successfully rewetted the peat, having raised the height of the water table relative to the drained site. Mean microbial activity rates at the drained site were found to be 33 % greater than the undisturbed intact peat and almost double that of the restored, drain-blocked site. These results correspond well with previously published data observing significantly greater DOC concentrations in the pore waters of the drained site and significantly lower concentrations at the blocked site, relative to the intact peat. Data from the drain-blocked treatment also provides evidence contrary to the commonly quoted hypothesis that an enzyme-latch reaction may be sustained in drained peat, even once it has been rewetted following water table restoration. Data is also presented that demonstrates how earlier research using INT-Formazan to assess microbial activity in peat, which has not incorporated correction for the spectrophotometric interference incurred from coloured DOC compounds, should be treated with caution.

  1. Rapid immobilisation and leaching of wet-deposited nitrate in upland organic soils.

    PubMed

    Evans, Chris D; Norris, Dave; Ostle, Nick; Grant, Helen; Rowe, Edwin C; Curtis, Chris J; Reynolds, Brian

    2008-12-01

    Nitrate (NO3-) is often observed in surface waters draining terrestrial ecosystems that remain strongly nitrogen (N) limited. It has been suggested that this occurs due to hydrological bypassing of soil or vegetation N retention, particularly during high flows. To test this hypothesis, artificial rain events were applied to 12 replicate soil blocks on a Welsh podzolic acid grassland hillslope, labelled with 15N-enriched NO3- and a conservative bromide (Br-) tracer. On average, 31% of tracer-labelled water was recovered within 4 h, mostly as mineral horizon lateral flow, indicating rapid vertical water transfer through the organic horizon via preferential flowpaths. However, on average only 6% of 15N-labelled NO3- was recovered. Around 80% of added NO3- was thus rapidly immobilised, probably by microbial communities present on the surfaces of preferential flowpaths. Transitory exceedance of microbial N-uptake capacity during periods of high water and N flux may therefore provide a mechanism for NO3- leaching. PMID:18653264

  2. 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 edges were magnetically separated from the 15-30 cm of topsoil cores. In order to determinate the mineralogical composition of magnetic particles in soil samples a SEM-EDS technique was used. On the base of the magnetic prescreening the archeological excavations on the study area are planning.

  3. Metal and arsenic impacts to soils, vegetation communities and wildlife habitat in southwest Montana uplands contaminated by smelter emissions. 1: Field evaluation

    SciTech Connect

    Galbraith, H.; LeJeune, K.; Lipton, J.

    1995-11-01

    Concentrations of arsenic and metals in soils surrounding a smelter in southwest Montana were correlated with vegetative community structure and composition and wildlife habitat quality. Soils in the uplands surrounding the smelter were highly enriched with arsenic and metals. Concentrations of these analytes decreased with distance from the smelter and with soil depth, suggesting that the smelter is the source of the enrichment. In enriched areas, marked modifications to the native vegetation community structure and composition were observed. These included replacement of evergreen forest with bare unvegetated ground; species impoverishment and increased dominance by weed species in grasslands; and reductions in the vertical complexity of the habitat. Significant negative correlations existed between soil arsenic and metals concentrations and the extent of vegetative cover and the vertical diversity of plant communities. Loss of vegetative cover in the affected areas has been accompanied by reductions in their capacity to support indigenous wildlife populations.

  4. 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 than the seeded, limed and fertilised only site, as well as the seeded, limed, C. vulgaris mulched site. This is possibly related to vegetation and litter layer establishment. A suite of water quality data (conductivity, pH and cation data) are now being analysed in combination with DOC to increase understanding of the relationship between bare site re-vegetation and DOC compositional change.

  5. Peat surface GHG fluxes related to peat hydrology in various tropical peat land uses

    NASA Astrophysics Data System (ADS)

    Jauhiainen, Jyrki; Silvennoinen, Hanna; Limin, Suwido; Vasander, Harri

    2010-05-01

    It is generally accepted that the gradual increase in the mean temperature of the Earth's surface is primarily due to rising concentrations of greenhouse gases (GHG), especially carbon dioxide (CO2), methane (CH4) and nitrous oxide (N2O) in the atmosphere. Tropical peatlands are an important component of the global peatland resource, contributing to terrestrial carbon storage in both their above-ground biomass (peat swamp forest) and underlying thick deposits of peat, which both participate soil-atmosphere carbon exchange processes. In their natural state, these forests have the ability to sequester carbon from the atmosphere during photosynthesis, retain this in plant biomass and store part of it in the peat. This process occurs mainly because of the frequent waterlogged condition of the peat, which reduces organic matter decomposition significantly and this causes the rate of organic matter production to exceed its breakdown. Peatland development, however, requires drainage, brings about changes in the vegetation type C-sequestration capacity and leads to changes in peat organic matter dynamics. Drainage promotes the depth of oxic conditions deeper in peat profile and thus speeds up peat stored organic matter mineralization. Aerobic conditions and high redox potentials created by drainage are known to favour microbial activity, which can enhance C and N losses by peat mineralization. Large areas of tropical peat have been drained, resulting in an abrupt and permanent shift in the ecosystem carbon balance from sink to source. Discussion of the current role of tropical peatlands in regional and global climate change processes is based mostly on circumstantial and secondary evidence, largely because total ecosystem carbon balance studies are very few and unsatisfactory. Peat surface GHG flux data are spatially very fragmented and have not usually been collected over entire diurnal or seasonal cycles. Interpretation of the impact of biophysical factors of tropical peat on tropical peat carbon dynamics is very difficult because of variations in environmental conditions (especially peat hydrology), peat and vegetation that are not collected systematically or reported adequately in studies. In this paper we (i.) compare the most important greenhouse gases, i.e. CO2, CH4, and N2O, related to peatland hydrology in typical land use types and peat drainage intensities, and (ii.) assess gaps existing in currently available GHG data collected from tropical peat in South-East Asia. Presented information is derived from our established GHG flux monitoring programs and reviewed values from literature. Land use types in GHG comparisons include selectively logged non-drained and drainage affected peat swamp forests, plantations, agricultural peat, and mismanaged abandoned peatlands. The results are discussed on basis of GHG dynamics controlling factors in various tropical peat land uses.

  6. Interactive effects of fire, soil climate, and vegetation on CO2 fluxes in an upland black spruce forest and peatland in interior Alaska

    NASA Astrophysics Data System (ADS)

    O'Donnell, J. A.; Turetsky, M. R.; Harden, J. W.; Manies, K. L.; Pruett, L. E.

    2007-12-01

    Fire is an important control on the carbon (C) balance of the boreal forest. In addition to the immediate release of stored C to the atmosphere through organic matter combustion, fire has the capacity to alter controls on decomposition, through changes in soil climate and substrate quality. Here, we present findings from two complimentary studies that examine how fire modifies the physical properties of soil and how these modifications influence rates of decomposition and C exchange in Alaska's boreal forest. First, we conducted a laboratory study to evaluate the interactive effects of fire, soil temperature, soil moisture, and moss type on CO2 fluxes from organic soils. Second, we conducted intensive field measurements of ecosystem CO2 fluxes in a 3 year-old burn to evaluate the effect of fire on carbon exchange in an upland forest and peatland in interior Alaska. Incubation CO2 fluxes showed a significant interaction between burn status (burned, unburned sites), temperature (2 C vs. 20 C treatments), and moisture treatment (field moisture vs. saturated). Incubation CO2 fluxes in the unburned sites increased with temperature by a factor of 5 and 29, whereas incubation CO2 fluxes in the burned sites only increased by 6 to 8 times. Incubation CO2 fluxes in the unburned sites increased with moisture content between 19 and 24 times, whereas incubation CO2 fluxes in the burned sites only increased by a factor of 4. Incubation CO2 fluxes from unburned Sphagnum samples were nearly 3 times greater than fluxes from burned Sphagnum. In the field At 3 years post-burn, moisture content was higher in the burned upland forest and burned peatland relative the unburned sites. However, soil temperature was not significantly different between burned and unburned sites. Mean rates of net ecosystem exchange (NEE) showed greater rates of CO2 uptake in the unburned peatland site than in the burned peatland, averaging -1.51 and 0.16 g C m-2 d-1, respectively. NEE rates were not significantly different in the two upland forest sites, averaging 0.0005 g C m-2 d-1 across sites. Mean rates of ecosystem respiration (ER) were not significantly different between the burned and unburned upland forest sites, averaging 0.9 g C m-2 d-1 overall. ER rates were not different between the burned and unburned peatland sites, averaging 1.4 m-2 d-1 overall. Soil temperature and moisture content accounted for between 20 to 45 % of the variation in ER rates in unburned upland forest and unburned peatland, and less than 10 % in the two burned sites. These findings, together with the incubation study, suggest that while fire creates soil climate conditions more conducive to rapid decomposition, rates of C release from soils may be constrained following fire by changes in litter quality that slow rates of decomposition.

  7. Reduction of iron (III) and humic substances plays a major role in anaerobic respiration in an Arctic peat soil

    NASA Astrophysics Data System (ADS)

    Lipson, David A.; Jha, Mony; Raab, Theodore K.; Oechel, Walter C.

    2010-12-01

    Arctic peat soils contain vast reserves of organic C and are largely anaerobic. However, anaerobic respiration, particularly the role of Fe(III) and humic substances as electron acceptors, is not well understood in such ecosystems. We investigated these processes in a drained thaw lake basin on the Arctic coastal plain near Barrow, Alaska. We measured concentrations of soluble Fe and other potential electron acceptors, described the microbial community, and performed experiments in the laboratory and field to measure net rates of Fe(III) reduction and the relationship of this process to C cycling. In most areas within the basin, aerobic conditions existed only in the upper few centimeters of soil, though oxygen penetrated deeper in raised areas, such as rims of ice wedge polygons. Concentrations of nitrate and sulfate in soil pore water were low or negligible. Soil pore water contained surprisingly high concentrations of Fe(II) and Fe(III), in the range of hundreds of ?M, suggesting the presence of organic chelators. The solid phase contained substantial amounts of iron minerals, with a progressively reduced oxidation state throughout the growing season. The most abundant 16S rRNA sequence in our gene survey was closely related to the Fe(III)-reducing bacterium, Rhodoferax ferrireducens, and other sequences closely related to Fe-transforming bacteria were found. Field and laboratory incubations with soluble Fe(III) and the quinonic compound, AQDS (a common humic analog), stimulated respiration and verified that Fe(III) reduction occurs in these soils. We conclude that reduction of Fe(III) and humic substances are major metabolic pathways in this ecosystem.

  8. Determination of low methylmercury concentrations in peat soil samples by isotope dilution GC-ICP-MS using distillation and solvent extraction methods.

    PubMed

    Pietilä, Heidi; Perämäki, Paavo; Piispanen, Juha; Starr, Mike; Nieminen, Tiina; Kantola, Marjatta; Ukonmaanaho, Liisa

    2015-04-01

    Most often, only total mercury concentrations in soil samples are determined in environmental studies. However, the determination of extremely toxic methylmercury (MeHg) in addition to the total mercury is critical to understand the biogeochemistry of mercury in the environment. In this study, N2-assisted distillation and acidic KBr/CuSO4 solvent extraction methods were applied to isolate MeHg from wet peat soil samples collected from boreal forest catchments. Determination of MeHg was performed using a purge and trap GC-ICP-MS technique with a species-specific isotope dilution quantification. Distillation is known to be more prone to artificial MeHg formation compared to solvent extraction which may result in the erroneous MeHg results, especially with samples containing high amounts of inorganic mercury. However, methylation of inorganic mercury during the distillation step had no effect on the reliability of the final MeHg results when natural peat soil samples were distilled. MeHg concentrations determined in peat soil samples after distillation were compared to those determined after the solvent extraction method. MeHg concentrations in peat soil samples varied from 0.8 to 18 μg kg(-1) (dry weight) and the results obtained with the two different methods did not differ significantly (p=0.05). The distillation method with an isotope dilution GC-ICP-MS was shown to be a reliable method for the determination of low MeHg concentrations in unpolluted soil samples. Furthermore, the distillation method is solvent-free and less time-consuming and labor-intensive when compared to the solvent extraction method. PMID:25434268

  9. Influence of geology, regolith and soil on fluid flow pathways in an upland catchment in central NSW, Australia

    NASA Astrophysics Data System (ADS)

    Bernardi, Tony

    2014-05-01

    Influence of geology, regolith and soil on fluid flow pathways in an upland catchment in central NSW, Australia. Tony Bernardi and Leah Moore Dryland Salinity Hazard Mitigation Program (DSHMP), University of Canberra, ACT 2601, AUSTRALIA The diversity of salt expression in central NSW has defied classification because salt expression, mobilisation and transport is highly variable and is typically site specific. Hydrological models are extensively used to simulate possible outcomes for a range of land use changes to mitigate the mobilisation and transport of salt into the streams or across the land surface. The ability of these models to mimic reality can be variable thereby reducing the confidence in the models outputs and uptake of strategic management changes by the community. This study focuses on a 250 ha semi-arid sub-catchment of Little River catchment in central west NSW in the Murray-Darling Basin, Australia. We propose that an understanding the structure of the landforms and configuration of rock, regolith and soil materials at the study site influences fluid flow pathways in the landscape and can be related to observed variations in the chemical composition and salinity of surface and aquifer water. Preliminary geological mapping of the site identified the dominant rock type as a pink and grey dacite and in localised mid-slope areas, a coarsely crystalline biotite-phyric granodiorite. Samples were taken at regular intervals from natural exposures in eroded stream banks and in excavations made during the installation of neutron moisture meter tubes. In order to establish mineral weathering pathways, samples were taken from the relatively unweathered core to the outer weathered 'onion skins' of corestones on both substrates, and then up through the regolith profile, including the soil zone, to the land surface. X-ray diffraction (XRD) analysis and X-ray fluorescence (XRF) was conducted on the rock and soil/saprock samples. Electromagnetic induction (EMI) profile data were compiled from previous work with colleagues in this area. Preliminary interpretation of the mapping and the geophysics is that there is a three-layer framework for groundwater modelling: fractured granitic rock with an irregular upper surface, finer-grained (volcanic) rock that has either mantled the older granite or has been intruded into, and a weathering profile developed in relation to the land surface. More careful interpretation of the intervals that shallow and deep piezometers and shallow and deep bores are sampling indicates that variability in water chemistry between holes can, in part, be explained because they are sampling different materials in the sub-surface geology/regolith geology. Quartz is a relatively resistant phase throughout the profiles. For both substrates there is a decrease in the feldspar in increasingly weathered regolith materials, with a corresponding increase in kaolinite clay. There is increased homogenisation of the profile, and some horizonation due to pedogenic processes (e.g. bioturbation, illuviation of fines down profile) nearer the land surface. This results in a concentration of more resistant phases (quartz and remnant primary feldspar as sands) at the land surface over the granitic substrate, however kaolinite persists in the profile over the finer substrate. The presence of measurable ferruginous oxides and sesquioxides relates to localised percolation of oxidising fluids through the profiles. Understanding the configuration and composition of rocks and regolith materials in the Baldry catchment facilitates interpretation of observed patterns in hydrological analyses.

  10. Copper tolerance of the biomass crops Elephant grass (Pennisetum purpureum Schumach), Vetiver grass (Vetiveria zizanioides) and the upland reed (Phragmites australis) in soil culture.

    PubMed

    Liu, Xinghua; Shen, Yixing; Lou, Laiqing; Ding, Chenglong; Cai, Qingsheng

    2009-01-01

    Pot trials were conducted to study the influence of copper (Cu) on the growth and biomass of Elephant grass (EG, Pennisetum purpureum Schumach), Vetiver grass (VG, Vetiveria zizanioides) and the upland reed (UR, Phragmites australis). Cu toxicity in EG, VG and UR was positively correlated with the total and bioavailable Cu concentrations in the soil. Based on the EC50, dry weights, Cu contents, chlorophyll contents and photosynthesis rates, the Cu tolerance of the three species followed the trend EGNVGNUR. There were no significant differences in the unit calorific values among the different plants, though the total calorific values of EG were higher than those of VG and UR due to its higher biomass. The addition of KH2PO4 to the soil decreased the bioavailability of Cu and the Cu uptake by plants. EG could therefore be a good candidate for growth on Cu-contaminated soils, especially those improved by phosphate. PMID:19393734

  11. Soil organic carbon sequestration in upland soils of northern China under variable fertilizer management and climate change scenarios

    NASA Astrophysics Data System (ADS)

    Jiang, Guiying; Xu, Minggang; He, Xinhua; Zhang, Wenju; Huang, Shaomin; Yang, Xueyun; Liu, Hua; Peng, Chang; Shirato, Yasuhito; Iizumi, Toshichika; Wang, Jinzhou; Murphy, Daniel V.

    2014-03-01

    We determined the historical change in soil organic carbon (SOC) stocks from long-term field trials that represent major soil types and climatic conditions of northern China. Soil carbon and general circulation models were validated using these field trial data sets. We then applied these models to predict future change in SOC stocks to 2100 using two net primary production (NPP) scenarios (i.e., current NPP or 1% year-1 NPP increase). The conversion rate of plant residues to SOC was higher in single-cropping sites than in double-cropping sites. The prediction of future SOC sequestration potential indicated that these soils will be a net source of carbon dioxide (CO2) under no fertilizer inputs. Even when inorganic nutrients were applied, the additional carbon input from increased plant residues could not meet the depletion of SOC in parts of northern China. Manure or straw application could however improve the SOC sequestration potential at all sites. The SOC sequestration potential in northern China was estimated to be -4.3 to 18.2 t C ha-1 by 2100. The effect of projected climate change on the annual rate of SOC change did not differ significantly between climate scenarios. The average annual rate of SOC change under current and increased NPP scenarios (at 850 ppm CO2) was approximately 0.136 t C ha-1 yr-1 in northern China. These findings highlight the need to maintain, and where possible increase, organic carbon inputs into these farming systems which are rapidly becoming inorganic fertilizer intensive.

  12. Is it clean or contaminated soil? Using petrogenic versus biogenic GC-FID chromatogram patterns to mathematically resolve false petroleum hydrocarbon detections in clean organic soils: a crude oil-spiked peat microcosm experiment.

    PubMed

    Kelly-Hooper, Francine; Farwell, Andrea J; Pike, Glenna; Kennedy, Jocelyn; Wang, Zhendi; Grunsky, Eric C; Dixon, D George

    2013-10-01

    The Canadian Council of Ministers of the Environment (CCME) reference method for the Canada-wide standard (CWS) for petroleum hydrocarbon (PHC) in soil provides chemistry analysis standards and guidelines for the management of contaminated sites. However, these methods can coextract natural biogenic organic compounds (BOCs) from organic soils, causing false exceedences of toxicity guidelines. The present 300-d microcosm experiment used CWS PHC tier 1 soil extraction and gas chromatography-flame ionization detector (GC-FID) analysis to develop a new tier 2 mathematical approach to resolving this problem. Carbon fractions F2 (C10-C16), F3 (C16-C34), and F4 (>C34) as well as subfractions F3a (C16-C22) and F3b (C22-C34) were studied in peat and sand spiked once with Federated crude oil. These carbon ranges were also studied in 14 light to heavy crude oils. The F3 range in the clean peat was dominated by F3b, whereas the crude oils had approximately equal F3a and F3b distributions. The F2 was nondetectable in the clean peat but was a significant component in crude oil. The crude oilspiked peat had elevated F2 and F3a distributions. The BOC-adjusted PHC F3 calculation estimated the true PHC concentrations in the spiked peat. The F2:F3b ratio of less than 0.10 indicated PHC absence in the clean peat, and the ratio of greater than or equal to 0.10 indicated PHC presence in the spiked peat and sand. Validation studies are required to confirm whether this new tier 2 approach is applicable to real-case scenarios. Potential adoption of this approach could minimize unnecessary ecological disruptions of thousands of peatlands throughout Canada while also saving millions of dollars in management costs. PMID:23703885

  13. Dissolved organic carbon concentrations and compositions, and trihalomethane formation potentials in waters from agricultural peat soils, Sacramento-San Joaquin Delta, California; implications for drinking-water quality

    USGS Publications Warehouse

    Fujii, Roger; Ranalli, Anthony J.; Aiken, George R.; Bergamaschi, Brian A.

    1998-01-01

    Water exported from the Sacramento-San Joaquin River delta (Delta) is an important drinking-water source for more than 20 million people in California. At times, this water contains elevated concentrations of dissolved organic carbon and bromide, and exceeds the U.S. Environmental Protection Agency's maximum contaminant level for trihalomethanes of 0.100 milligrams per liter if chlorinated for drinking water. About 20 to 50 percent of the trihalomethane precursors to Delta waters originates from drainage water from peat soils on Delta islands. This report elucidates some of the factors and processes controlling and affecting the concentration and quality of dissolved organic carbon released from peat soils and relates the propensity of dissolved organic carbon to form trihalomethanes to its chemical composition.Soil water was sampled from near-surface, oxidized, well-decomposed peat soil (upper soil zone) and deeper, reduced, fibrous peat soil (lower soil zone) from one agricultural field in the west central Delta over 1 year. Concentrations of dissolved organic carbon in the upper soil zone were highly variable, with median concentrations ranging from 46.4 to 83.2 milligrams per liter. Concentrations of dissolved organic carbon in samples from the lower soil zone were much less variable and generally slightly higher than samples from the upper soil zone, with median concentrations ranging from 49.3 to 82.3 milligrams per liter. The dissolved organic carbon from the lower soil zone had significantly higher aromaticity (as measured by specific ultraviolet absorbance) and contained significantly greater amounts of aromatic humic substances (as measured by XAD resin fractionation and carbon-13 nuclear magnetic resonance analysis of XAD isolates) than the dissolved organic carbon from the upper soil zone. These results support the conclusion that more aromatic forms of dissolved organic carbon are produced under anaerobic conditions compared to aerobic conditions. Dissolved organic carbon concentration, trihalomethane formation potential, and ultraviolet absorbance were all highly correlated, showing that trihalomethane precursors increased with increasing dissolved organic carbon and ultraviolet absorbance for whole water samples. Contrary to the generally accepted conceptual model for trihalomethane formation that assumes that aromatic forms of carbon are primary precursors to trihalomethanes, results from this study indicate that dissolved organic carbon aromaticity appears unrelated to trihalomethane formation on a carbon-normalized basis. Thus, dissolved organic carbon aromaticity alone cannot fully explain or predict trihalomethane precursor content, and further investigation of aromatic and nonaromatic forms of carbon will be needed to better identify trihalomethane precursors.

  14. The peats of Costa Rica

    SciTech Connect

    Obando A, L.; Malavassi R, L.; Ramirez E, O. ); Cohen, A. . Dept. of Geological Sciences); Raymond, R. Jr.; Thayer, G.R. )

    1991-04-01

    The objectives of this investigation were: (1) to locate potential peat deposits in Costa Rica; (2) to estimate as closely as possible by representative sampling the amount of peat present in each deposit, and (3) to make a preliminary evaluation of the quality of the peat in each deposit. With information from soil maps and a 3-week survey of Costa Rica, it is estimated that a potential area of about 1000 km{sup 2} is covered by peat. Most of the peat area (about 830 km{sup 2}) is in northeastern Costa Rica in the Tortuguero area. An aerial survey identified the potential peat areas by the exclusive presence of the Yolillo palm. The next largest potential area of peat (about 175 km{sup 2}) is in the cloud-covered areas of the Talamanca Mountains. Some reconnaissance has been done in the Talamanca Mountains, and samples of the peat indicate that it is very similar to the sphagnum peat moss found in Canada and the northern US. Smaller bogs have been discovered at Medio Queso, El Cairo, Moin, and the Limon airport. Two bogs of immediate interest are Medio Queso and El Cairo. The Medio Queso bog has been extensively sampled and contains about 182,000 metric tons (dry) of highly decomposed peat, which is being used as a carrier for nitrogen-fixing bacteria. The El Cairo bog is sparsely sampled and contains about 1,300,000 metric tons of slightly decomposed dry peat. Plans are to use this peat in horticultural applications on nearby farms. 10 refs., 11 figs., 7 tabs.

  15. Evidence for an eolian origin for the silt-enriched soil mantles on the glaciated uplands of eastern Upper Michigan, USA

    USGS Publications Warehouse

    Schaetzl, R.J.; Loope, W.L.

    2008-01-01

    We provide textural, geochemical, and mineralogical data on a thin, silty deposit that unconformably mantles glaciated uplands in the eastern Upper Peninsula of Michigan. Previous research on this deposit, which we hypothesize to be loess, is nonexistent. The uplands were islands or narrow peninsulas within one or more glacial lakes. We compare the distribution, likely source and nature of the 20-60??cm thick silty mantle by using the loess formation model of Mason et al. [Mason, J.A., Nater, E.A., Zanner, C.W., Bell, J.C., 1999. A new model of topographic effects on the distribution of loess. Geomorphology 28, 223-236], which focuses on the generation of eolian silt by saltating sand across upwind, barren surfaces. Parabolic dunes, with arms open to the NW, are common on former lake floors upwind of the silt-mantled uplands, attesting to the strength and direction of paleowinds. The abrupt termination of the dunes at the footslopes of the uplands, associated with silt deposition on upland soil surfaces in downwind locations, are both consistent with the model of Mason et al. [Mason, J.A., Nater, E.A., Zanner, C.W., Bell, J.C., 1999. A new model of topographic effects on the distribution of loess. Geomorphology 28, 223-236]. Sediments on former lake floors contain abundant strata of fine/medium sand and silt, and thus are likely sources for the silt and dune sand. The cap, dune and lake sediments are similar along many different geochemical axes, whereas the substrate sediment, i.e., the drift below the cap, is unique. Cap sediments, normally containing roughly 30% silt, are enriched in quartz and depleted in Ti and Zr, relative to dune sediment. The dune sediment, a more residual eolian deposit, is enriched in Ti and Zr, relative to the cap, probably due to its greater abundance of heavy minerals. Therefore, we conclude that the silty cap is loess that was deflated from abandoned lake floors after nearby glacial lakes drained, probably contemporaneously with dune migration across the former lake floors. ?? 2008 Elsevier B.V. All rights reserved.

  16. Reorganization of vegetation, hydrology and soil carbon after permafrost degradation across heterogeneous boreal landscapes

    USGS Publications Warehouse

    Jorgenson, M. Torre; Harden, Jennifer; Kanevskiy, Mikhail; O'Donnell, Jonathan; Wickland, Kim; Ewing, Stephanie; Manies, Kristen; Zhuang, Qianlai; Shur, Yuri; Striegl, Robert; Koch, Josh

    2013-01-01

    The diversity of ecosystems across boreal landscapes, successional changes after disturbance and complicated permafrost histories, present enormous challenges for assessing how vegetation, water and soil carbon may respond to climate change in boreal regions. To address this complexity, we used a chronosequence approach to assess changes in vegetation composition, water storage and soil organic carbon (SOC) stocks along successional gradients within four landscapes: (1) rocky uplands on ice-poor hillside colluvium, (2) silty uplands on extremely ice-rich loess, (3) gravelly–sandy lowlands on ice-poor eolian sand and (4) peaty–silty lowlands on thick ice-rich peat deposits over reworked lowland loess. In rocky uplands, after fire permafrost thawed rapidly due to low ice contents, soils became well drained and SOC stocks decreased slightly. In silty uplands, after fire permafrost persisted, soils remained saturated and SOC decreased slightly. In gravelly–sandy lowlands where permafrost persisted in drier forest soils, loss of deeper permafrost around lakes has allowed recent widespread drainage of lakes that has exposed limnic material with high SOC to aerobic decomposition. In peaty–silty lowlands, 2–4 m of thaw settlement led to fragmented drainage patterns in isolated thermokarst bogs and flooding of soils, and surface soils accumulated new bog peat. We were not able to detect SOC changes in deeper soils, however, due to high variability. Complicated soil stratigraphy revealed that permafrost has repeatedly aggraded and degraded in all landscapes during the Holocene, although in silty uplands only the upper permafrost was affected. Overall, permafrost thaw has led to the reorganization of vegetation, water storage and flow paths, and patterns of SOC accumulation. However, changes have occurred over different timescales among landscapes: over decades in rocky uplands and gravelly–sandy lowlands in response to fire and lake drainage, over decades to centuries in peaty–silty lowlands with a legacy of complicated Holocene changes, and over centuries in silty uplands where ice-rich soil and ecological recovery protect permafrost.

  17. Measurement of Entrapped Biogenic Gas Bubbles in Northern Peat Soils: Application of Resistivity and X-ray Computed Tomography.

    NASA Astrophysics Data System (ADS)

    Kettridge, N.; Binley, A.; Baird, A.

    2008-05-01

    Peatlands are the largest natural source per annum of CH4 emissions to the atmosphere. CH4 is lost from peatlands via diffusion or active transport through vascular plants, and as bubbles moving to the peatland surface - ebullition. The build up and ebullition of biogenic gas bubbles within northern peatlands is spatially variable and depends on the rate of CH4 production, the transport of dissolved CH4 to bubbles through pore water, and the physical properties of the peat. Recent measurements suggest a threshold bubble volume must be reached to trigger episodic or cyclic ebullition, which is assumed to be dependent on peat type. However, this threshold theory lacks a secure physical basis and therefore cannot be applied to simulate methane ebullition from northern peatlands with any confidence. We develop an approach to examine the structural attributes of the peat that cause and promote the trapping and release of bubbles by combining resistivity and X-ray computed tomography (CT). The spatial and temporal variation in the biogenic gas content of peat cores are identified from resistivity measurements. Areas of high and low entrapped gas content are subsequently correlated with the pore structure of the peat samples, characterised using CT. The CT images of the peat structure are vectorised to allow them to be analysed for metrics which relate to the ability of the peat to trap bubbles: e.g. stem length and width, number of branches, angle of branches. Difficulties applying these approaches within northern peatlands are examined. The low pore water conductivity of poorly decomposed near surface peat can hamper resistivity measurements at the laboratory scale, and electrolytic reactions induce the development of artificial gas bubbles. The similarity in linear attenuations between poorly decomposed Sphagnum and pore water also makes the peat structure indistinguishable from the pore water within standard CT scans. The peat samples must, therefore, first be doped with a solution of lead(II) nitrate which is adsorbed by the peat fibres, making them visible.

  18. Soil data from fire and permafrost-thaw chronosequences in upland Picea mariana stands near Hess Creek and Tok, interior Alaska

    USGS Publications Warehouse

    O'Donnell, Jonathan A.; Harden, Jennifer W.; Manies, Kristen L.; Jorgenson, M. Torre; Kanevskiy, Mikhail; Xu, Xiaomei

    2013-01-01

    Soils of the Northern Circumpolar Permafrost region harbor 1,672 petagrams (Pg) (1 Pg = 1,000,000,000 kilograms) of organic carbon (OC), nearly 50 percent of the global belowground OC pool (Tarnocai and others, 2009). Of that soil OC, nearly 88 percent is presently stored in perennially frozen ground. Recent climate warming at northern latitudes has resulted in warming and thawing of permafrost in many regions (Osterkamp, 2007), which might mobilize OC stocks from associated soil reservoirs via decomposition, leaching, or erosion. Warming also has increased the magnitude and severity of wildfires in the boreal region (Turetsky and others, 2011), which might exacerbate rates of permafrost degradation relative to warming alone. Given the size and vulnerability of the soil OC pool in permafrost soils, permafrost thaw will likely function as a strong positive feedback to the climate system (Koven and others, 2011; Schaefer and others, 2011). In this report, we report soil OC inventories from two upland fire chronosequences located near Hess Creek and Tok in Interior Alaska. We sampled organic and mineral soils in the top 2 meters (m) across a range of stand ages to evaluate the effects of wildfire and permafrost thaw on soil C dynamics. These data were used to parameterize a simple process-based fire-permafrost-carbon model, which is described in detail by O’Donnell and others (2011a, b). Model simulations examine long-term changes in soil OC storage in response to fire, permafrost thaw, and climate change. These data also have been used in other papers, including Harden and others (2012), which examines C recovery post-fire, and Johnson and others (2011), which synthesizes data within the Alaska Soil Carbon Database. Findings from these studies highlight the importance of climate and disturbance (wildfire, permafrost thaw) on soil C storage, and loss of soil C from high-latitude ecosystems.

  19. Metal and arsenic impacts to soils, vegetation communities and wildlife habitat in southwest Montana uplands contaminated by smelter emissions. 2: Laboratory phytotoxicity studies

    SciTech Connect

    Kapustka, L.A.; Lipton, J.; Galbraith, H.; Cacela, D.; LeJeune, K.

    1995-11-01

    Vegetation communities on metal- and arsenic-contaminated uplands surrounding a smelter in southwest Montana have been eliminated or highly modified. Laboratory toxicity tests were performed using site soils from the impacted areas to determine whether the soils limit the ability of plants to establish and grow. The germination and growth of alfalfa, lettuce, and wheat in impacted area soils was compared to germination and growth of the three species in reference soils. The degree of phytotoxicity was quantified using a species-endpoint toxicity score calculated on the magnitude of difference between germination and growth of plants in impacted and reference soils. The impacted soils exhibited substantial toxicity to plants: 5% of the sites were severely phytotoxic, 55% were highly phytotoxic, 10% were moderately phytotoxic, 20% were mildly phytotoxic, and 10% were nontoxic. Root growth was consistently the most affected endpoint (18 of 20 impacted soils) and reduction in root length and mass was observed. Correlation and partial correlation analysis was used to evaluate the causes of phytotoxicity. Concentrations of As, Cu, and Zn and, to a lesser extent, Pb and Cd were found to be positively correlated with phytotoxicity.

  20. The pool of pedogenic carbon in the soils of different types and durations of use as croplands in the forest-steppe of the Central Russian Upland

    NASA Astrophysics Data System (ADS)

    Khokhlova, O. S.; Chendev, Yu. G.; Myakshina, T. N.; Shishkov, V. A.

    2013-05-01

    Based on studying five agrochronoseries, including recent forest (dark) gray soils and soils plowed for 100, 150, and 200-240 and more years in the forest-steppe zone of the Central Russian Upland, the dynamics of the pedogenic carbon pool, including the Corg and Ccarb, are considered. In the 2-m-thick layer of the agrogenic soils studied, the pedogenic carbon pool was shown to increase by 15-30% (up to 50%) mainly due to the changes in the Ccarb content. The insignificant (by ˜10%) growth of the Corg content was found in the soils that were plowed for more than 200-250 years. As the hydrothermal regime changed when passing from the forest to croplands, the Ccarb reserves increased due to the ascending of carbonates from the parent rock through the capillary pores, probably, in colloid solution-suspensions. This process proceeded without exchange with the soil CO2, since the 14C age and the content of the newly formed carbonates became higher. These carbonates may be called pedogenic-lithogenic agrocarbonates, since they appear in soils as a result of the (agro-) pedogenesis. In this case, their additional source is the lithogenic carbonates, which bring in the "old" carbon. The process of carbonates ascending could be referred to the rapid soil-forming ones with their implementation time being close to ≤50 years.

  1. Mycobiota of peat-gleyic soils during the process of recultivation

    NASA Astrophysics Data System (ADS)

    Ibatullina, I.; Khabibullina, F.

    2009-04-01

    The experiments on the recultivation of oil-polluted soils and their self-rehabilitation were laid in 1995 at sites contaminated with oil in the area of Usinsk region, Komi Republic, Russia. There were taken different plots for the experiment with various amounts of contaminant. The investigations continued some years after the contamination. At this point, the concentration of residual oil in these areas significantly decreased. Microbiological activity increased 2-3 times in the most contaminated soil. We should note that the micromycets were marked only in the layer 0-5sm in contrast to background soil. There were 10 species of micromycets and most of them characterized as dark colored species, the dominants were Aspergillus fumigatus. Penicillium funiculosum, P. paxilli, P. lanosum, P. tardum, usual for contaminated anthropogenic soils. The same highly oil-polluted soil, where recultivation was held, is characterized with the wider specter of different physiological groups of microorganisms. Micobiota is quite reach, it represents 20 species from 8 types. In the composition of micromycets 40% are the representatives of Penicillium, sterile mycelium presents as dark colored forms so as light colored ones. But the micobiota is still reach in micromycets typical for disturbed anthropogenic soils. The most microbiologically active plot was a territory with low-contaminated self-recovered soil. The micobiota is represented of great amount of microorganisms and consists of 21 species, mostly formed with dark colored forms of sterile mycelium. During the process of recultivation the structure of micromyctes changed: regrouping of species and increase of biodiversity. We assume that a process of self-purification started. However we should notice that activation of biological processes doesn't occur deeper than 0-5sm. At the same time the roots of high plants are seen till the depth 7-10sm, they also participate in the cleaning of oil polluted soil. There was used a Zhakkar coefficient of similarity to show the difference of mycobiota structure of rehabilitated ecosystems. The greatest similarity was observed between the communities of soil micromycetes from recultivated area and the area with low pollution (42.8%), the smallest - mycobiota of a non-polluted and heavily contaminated soil (5.4%). Mikobiota of virgin soil is characterized with the richest biodiversity of micromycetes species; rates of similarity coefficient between the mycobiota of virgin soils and oil-polluted here have the lowest value. In summary, we want to mark that micromycet complexes are changing in soils under the influence of oil pollution: first, a reduction in the diversity of fungal complexes in the soil, compared with the background, and secondly, there is an increase of dominant and often encountered species and reducing the number of rare species. There is also the appearance of fungi, which are typical for the more southern regions. Influenced by oil pollution the investigated soils become a sphere of accumulation of potentially hazardous to human species of micromycetes: Aspergillus fumigatus, Paecilomyces variotii, etc.

  2. Impact of managed moorland burning on peat nutrient and base cation status

    NASA Astrophysics Data System (ADS)

    Palmer, Sheila; Gilpin, Martin; Wearing, Catherine; Johnston, Kerrylyn; Holden, Joseph; Brown, Lee

    2013-04-01

    Controlled 'patch' burning of moorland vegetation has been used for decades in the UK to stimulate growth of heather (Calluna vulgaris) for game bird habitat and livestock grazing. Typically small patches (300-900 m2) are burned in rotations of 8-25 years. However, our understanding of the short-to-medium term environmental impacts of the practice on these sensitive upland areas has so far been limited by a lack of scientific data. In particular the effect of burning on concentrations of base cations and acid-base status of these highly organic soils has implications both for ecosystem nutrient status and for buffering of acidic waters. As part of the EMBER project peat chemistry data were collected in ten upland blanket peat catchments in the UK. Five catchments were subject to a history of prescribed rotational patch burning. The other five catchments acted as controls which were not subject to burning, nor confounded by other detrimental activities such as drainage or forestry. Soil solution chemistry was also monitored at two intensively studied sites (one regularly burned and one control). Fifty-centimetre soil cores, sectioned into 5-cm intervals, were collected from triplicate patches of four burn ages at each burned site, and from twelve locations at similar hillslope positions at each control site. At the two intensively monitored sites, soil solution chemistry was monitored at four depths in each patch. Across all sites, burned plots had significantly smaller cation exchange capacities, lower concentrations of exchangeable base cations and increased concentrations of exchangeable H+ and Al3+ in near-surface soil. C/N ratios were also lower in burned compared to unburned surface soils. There was no consistent trend between burn age and peat chemistry across all burned sites, possibly reflecting local controls on post-burn recovery rates or external influences on burn management decisions. At the intensively monitored site, plots burned less than two years prior to sampling had significantly smaller exchange capacities and lower concentrations of soil base cations in surface soils relative to plots burned 15-25 years previously. In contrast, surface soil solutions in recently burned plots were enriched in base cations relative to older plots and relative to the control site, possibly due to enhanced leaching at bare soil surfaces. The results offer evidence for an impact of burning on peat nutrient and acid-base status, but suggest that soils recover given time with no further burning.

  3. Effects of the application of digestates from wet and dry anaerobic fermentation to Japanese paddy and upland soils on short-term nitrification.

    PubMed

    Sawada, Kozue; Toyota, Koki

    2015-01-01

    Wet and dry anaerobic fermentation processes are operated for biogas production from organic matter, resulting in wet and dry digestates as by-products, respectively. The application of these digestates to soil as fertilizer has increased in recent years. Therefore, we herein compared the effects of applying wet digestates (pH 8.2, C/N ratio 4.5), dry digestates (pH 8.8, C/N ratio 23.4), and a chemical fertilizer to Japanese paddy and upland soils on short-term nitrification under laboratory aerobic conditions. Chloroform-labile C, an indicator of microbial biomass, was only minimally affected by these applications, indicating that a small amount of labile N was immobilized by microbes. All applications led to rapid increases in NO3 -N contents in both soils, and ammonia-oxidizing bacteria, but not archaea may play a critical role in net nitrification in the amended soils. The net nitrification rates for both soils were the highest after the application of dry digestates, followed by wet digestates and then the chemical fertilizer in order of decreasing soil pH. These results suggest that the immediate effects of applying digestates, especially dry digestates with the highest pH, on nitrate leaching need to be considered when digestates are used as alternative fertilizers. PMID:25740173

  4. Effects of the Application of Digestates from Wet and Dry Anaerobic Fermentation to Japanese Paddy and Upland Soils on Short-Term Nitrification

    PubMed Central

    Sawada, Kozue; Toyota, Koki

    2015-01-01

    Wet and dry anaerobic fermentation processes are operated for biogas production from organic matter, resulting in wet and dry digestates as by-products, respectively. The application of these digestates to soil as fertilizer has increased in recent years. Therefore, we herein compared the effects of applying wet digestates (pH 8.2, C/N ratio 4.5), dry digestates (pH 8.8, C/N ratio 23.4), and a chemical fertilizer to Japanese paddy and upland soils on short-term nitrification under laboratory aerobic conditions. Chloroform-labile C, an indicator of microbial biomass, was only minimally affected by these applications, indicating that a small amount of labile N was immobilized by microbes. All applications led to rapid increases in NO3 -N contents in both soils, and ammonia-oxidizing bacteria, but not archaea may play a critical role in net nitrification in the amended soils. The net nitrification rates for both soils were the highest after the application of dry digestates, followed by wet digestates and then the chemical fertilizer in order of decreasing soil pH. These results suggest that the immediate effects of applying digestates, especially dry digestates with the highest pH, on nitrate leaching need to be considered when digestates are used as alternative fertilizers. PMID:25740173

  5. Chemically enhanced mixed region vapor stripping of TCE-contaminated saturated peat and silty clay soils

    SciTech Connect

    West, O.R.; Cameron, P.A.; Lucero, A.J.; Koran, L.J. Jr.

    1996-01-01

    The objective of this study was to conduct further testing of MRVS, chemically enhanced with calcium oxide conditioning, on field- contaminated soils collected from beneath the NASA Michoud Rinsewater Impoundment. In this study, residual soil VOC levels as a function of vapor stripping time were measured to quantify VOC removal rates. Physical and chemical soil parameters expected to affect MRVS efficiency were measures. The effects of varying the calcium oxide loadings as well as varying the vapor stripping flow rates on VOC removal were also evaluated. The results of this study will be used to determine whether acceptable removals can be achieved within reasonable treatment times, remediation costs being directly proportional to the latter. The purpose of this report is to document the experimental results of this study, as well as to address issues that were raised after completion of the previous Michoud treatability work.

  6. Global Perspectives on Peat Fires

    NASA Astrophysics Data System (ADS)

    Watts, A.; Turetsky, M. R.; Benscoter, B.; Page, S. E.; Rein, G.; van der Werf, G.

    2014-12-01

    The global peat carbon pool exceeds that of global vegetation and is similar to the current atmospheric carbon pool. Because fire is increasingly appreciated as a threat to peatlands and their carbon stocks, here we discuss controls on and effects of peat fires across biomes and how they vary. Peat fires are dominated by smoldering combustion, which is easier to ignite and persists under greater moisture content than flaming combustion. In undisturbed peatlands, the peat C stock typically is protected from deep smoldering, and fire resistance has played a role in tropical and boreal peat carbon storage over millennia. However, drying mediated by climate change and anthropogenic activity is altering peatland hydrology and increasing the frequency and extent of peat fires; in some cases, processes of drying and fire may be coupled in positive feedbacks that could result in increasingly large fires and consequent releases of carbon to the atmosphere. The combustion of deep peat affects older soil carbon that has not been part of the active carbon cycle for centuries to millennia, and will dictate the importance of peat fire emissions with respect to future climate change and human health effects.

  7. Assessment by laboratory simulation of approaches to amelioration of peat acidification.

    PubMed

    Sanger, L J; Billett, M F; Cresser, M S

    1993-01-01

    The effects of different liming materials (CaCO(3), Ca(OH)(2), CaHPO(4), and dolomite) on soil and drainage-water chemistry have been investigated for upland acidic peats by using a soil-core-simulation experiment. Intact cores from three depths (0-30, 0-60, and 0-90 mm) were subjected to ten years of simulated rainfall. Drainage water was periodically analysed for Ca(2+), Mg(2+), Na(+), K(+) NH(4)(+), TOC, Cl(-), SO(4)(2-), NO(3)(-), PO(4)(3-), and pH, and at the end of the experiment the cores were destructively sampled and analysed. Temporal changes in soil and drainage-water chemistry are used to evaluate the advantages and disadvantages of using different liming materials for the amelioration of soil and drainage-water chemistry. PMID:15091833

  8. TRIHALOMETHANE REACTIVITY OF WATER- AND SODIUM HYDROXIDE-EXTRACTABLE ORGANIC CARBON FRACTIONS FROM PEAT SOILS.

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Certain organic carbon moieties in drinking source waters of the SacramentoSan Joaquin Delta can react with chlorine during disinfection to form potentially carcinogenic and mutagenic trihalomethanes. The properties of reactive organic carbon in Delta waters, particularly those of soil origin, have...

  9. The nitrogen composition of streams in upland Scotland: some regional and seasonal differences.

    PubMed

    Chapman, P J; Edwards, A C; Cresser, M S

    2001-01-29

    The nitrogen (N) composition of streams draining four upland regions of Scotland was compared in samples collected monthly between April 1997 and April 1998. Stream samples were analysed for total N (TN), particulate N (PN), nitrate (NO3), ammonium (NH4), dissolved organic N (DON) and dissolved organic carbon (DOC). Concentrations of TN were small, generally less than 1 mg l(-1) , dominated by dissolved forms of N, and varied significantly between upland regions. Nitrate accounted for most of the variability in TN; largest concentrations were observed in the Southern Uplands and smallest concentrations were observed in the Highlands. Nitrate concentrations were positively correlated with the percentage cover of improved grasslands and brown forest soils and negatively correlated with the percentage cover of peat. Concentrations of DON also varied between regions, but to a lesser extent than those of NO3. Largest concentrations occurred in SW Scotland and smallest concentrations in the Cairngorms. Although a significant positive correlation between DON and DOC was observed, stream water DON content was not related to the percentage cover of peat in the catchment, as was the case for DOC. The average DOC:DON ratio was narrower for streams in the Southern Uplands than for those in the Cairngorms and Highlands. Nitrate and DON displayed contrasting seasonal trends; NO3 concentrations were larger in the winter while DON concentrations were larger in the summer. Only a small proportion, < 8% and < 7%, of TN was PN and NH4, respectively, the majority of N was present as either NO3 or DON. Nitrate was the dominant fraction (58-65%) in all regions except the Highlands where DON accounted for 57% of TN. However, the relative importance of the DON component increased in the summer in all regions. This study has demonstrated that the DON fraction is an important component of the total N transported by streams from upland catchments in Scotland. Thus, assessments of anthropogenic impacts on N losses from upland ecosystems need to consider not only the dissolved inorganic species but also DON. PMID:11227283

  10. Effects of manure and mineral fertilization strategies on soil antibiotic resistance gene levels and microbial community in a paddy-upland rotation system.

    PubMed

    Lin, Hui; Sun, Wanchun; Zhang, Zulin; Chapman, Stephen J; Freitag, Thomas E; Fu, Jianrong; Zhang, Xin; Ma, Junwei

    2016-04-01

    This work investigated the responses of antibiotic resistance genes (ARGs) and the soil microbial community in a paddy-upland rotation system to mineral fertilizer (NPK) and different application dosages of manure combined with NPK. The occurrence of five tetracycline ARGs (tetA, tetB, tetC, tetG and tetW), two sulfonamide ARGs (sul1 and sul2) and one genetic element (IntI1) was quantified. NPK application showed only slight or no impact on soil ARGs abundances compared with the control without fertilizer. Soil ARGs abundances could be increased by manure-NPK application but was related to manure dosage (2250-9000 kg ha(-1)). Principal component analysis (PCA) showed that the soil ARG profile of the treatment with 9000 kg ha(-1) manure separated clearly from the other treatments; the ARGs that contributed most to the discrimination of this treatment were tetA, tetG, tetW, sul1, sul2 and IntI1. Community level physiological profile (CLPP) analysis showed that increasing manure dosage from 4500 kg ha(-1) to 9000 kg ha(-1) induced a sharp increase in almost all of the detected ARGs but would not change the microbial community at large. However, 9000 kg ha(-1) manure application produced a decline in soil microbial activity. Determination of antibiotics and heavy metals in soils suggested that the observed bloom of soil ARGs might associate closely with the accumulation of copper and zinc in soil. PMID:26774780

  11. Metagenomic Insights into Anaerobic Metabolism along an Arctic Peat Soil Profile

    PubMed Central

    Lipson, David A.; Haggerty, John Matthew; Srinivas, Archana; Raab, Theodore K.; Sathe, Shashank; Dinsdale, Elizabeth A.

    2013-01-01

    A metagenomic analysis was performed on a soil profile from a wet tundra site in northern Alaska. The goal was to link existing biogeochemical knowledge of the system with the organisms and genes responsible for the relevant metabolic pathways. We specifically investigated how the importance of iron (Fe) oxides and humic substances (HS) as terminal electron acceptors in this ecosystem is expressed genetically, and how respiratory and fermentative processes varied with soil depth into the active layer and into the upper permafrost. Overall, the metagenomes reflected a microbial community enriched in a diverse range of anaerobic pathways, with a preponderance of known Fe reducing species at all depths in the profile. The abundance of sequences associated with anaerobic metabolic processes generally increased with depth, while aerobic cytochrome c oxidases decreased. Methanogenesis genes and methanogen genomes followed the pattern of CH4 fluxes : they increased steeply with depth into the active layer, but declined somewhat over the transition zone between the lower active layer and the upper permafrost. The latter was relatively enriched in fermentative and anaerobic respiratory pathways. A survey of decaheme cytochromes (MtrA, MtrC and their homologs) revealed that this is a promising approach to identifying potential reducers of Fe(III) or HS, and indicated a possible role for Acidobacteria as Fe reducers in these soils. Methanogens appear to coexist in the same layers, though in lower abundance, with Fe reducing bacteria and other potential competitors, including acetogens. These observations provide a rich set of hypotheses for further targeted study. PMID:23741360

  12. Metagenomic insights into anaerobic metabolism along an Arctic peat soil profile.

    PubMed

    Lipson, David A; Haggerty, John Matthew; Srinivas, Archana; Raab, Theodore K; Sathe, Shashank; Dinsdale, Elizabeth A

    2013-01-01

    A metagenomic analysis was performed on a soil profile from a wet tundra site in northern Alaska. The goal was to link existing biogeochemical knowledge of the system with the organisms and genes responsible for the relevant metabolic pathways. We specifically investigated how the importance of iron (Fe) oxides and humic substances (HS) as terminal electron acceptors in this ecosystem is expressed genetically, and how respiratory and fermentative processes varied with soil depth into the active layer and into the upper permafrost. Overall, the metagenomes reflected a microbial community enriched in a diverse range of anaerobic pathways, with a preponderance of known Fe reducing species at all depths in the profile. The abundance of sequences associated with anaerobic metabolic processes generally increased with depth, while aerobic cytochrome c oxidases decreased. Methanogenesis genes and methanogen genomes followed the pattern of CH4 fluxes: they increased steeply with depth into the active layer, but declined somewhat over the transition zone between the lower active layer and the upper permafrost. The latter was relatively enriched in fermentative and anaerobic respiratory pathways. A survey of decaheme cytochromes (MtrA, MtrC and their homologs) revealed that this is a promising approach to identifying potential reducers of Fe(III) or HS, and indicated a possible role for Acidobacteria as Fe reducers in these soils. Methanogens appear to coexist in the same layers, though in lower abundance, with Fe reducing bacteria and other potential competitors, including acetogens. These observations provide a rich set of hypotheses for further targeted study. PMID:23741360

  13. The decomposition of vegetation and soil in marginal peat-forming landscapes: climate simulations to quantify gaseous and dissolved carbon fluxes and the effects on peat accumulation and drinking water treatment

    NASA Astrophysics Data System (ADS)

    Ritson, J.; Bell, M.; Clark, J. M.; Graham, N.; Templeton, M.; Brazier, R.; Verhoef, A.; Freeman, C.

    2013-12-01

    Peatlands in the UK represent a large proportion of the soil carbon store, however there is concern that some systems may be switching from sinks to sources of carbon. The accumulation of organic material in peatlands results from the slow rates of decomposition typically occurring in these regions. Climate change may lead to faster decomposition which, if not matched by an equivalent increase in net primary productivity and litter fall, may tip the balance between source and sink. Recent trends have seen a greater flux of dissolved organic matter (DOM) from peatlands to surface waters and a change in DOM character, presenting challenges to water treatment, for example in terms of increased production of disinfectant by-products (DBPs). Peat systems border a large proportion of reservoirs in the UK so uncertainty regarding DOM quantity and quality is a concern for water utilities. This study considered five peatland vegetation types (Sphagnum spp., Calluna vulgaris, Molinea caerulea, peat soil and mixed litter) collected from the Exmoor National Park, UK where it is hypothesised that peat formation may be strongly affected by future changes to climate. A factorial experiment design to simulate climate was used, considering vegetation type, temperature and rainfall amount using a current baseline and predictions from the UKCP09 model. Gaseous fluxes of carbon were monitored over a two month period to quantify the effect on carbon mineralisation rates while 13C NMR analysis was employed to track which classes of compounds decayed preferentially. The DOM collected was characterised using UV and fluorescence techniques before being subject to standard drinking water treatment processes (coagulation/flocculation followed by chlorination). The effect of the experimental factors on DOM amenability to removal and propensity to form DBPs was then considered, with both trihalomethane (THM) and haloacetonitrile (HAN) DBP classes monitored. Initial results have shown a statistically significant (Mann-Whitney U) difference in THM formation (p<0.05) as well as the amount of DOM produced and specific UV absorption at 254nm (p<0.01) between vegetation classes.

  14. Effect of reed canary grass cultivation on greenhouse gas emission from peat soil at controlled rewetting

    NASA Astrophysics Data System (ADS)

    Karki, S.; Elsgaard, L.; Lrke, P. E.

    2015-01-01

    Cultivation of bioenergy crops in rewetted peatland (paludiculture) is considered as a possible land use option to mitigate greenhouse gas (GHG) emissions. However, bioenergy crops like reed canary grass (RCG) can have a complex influence on GHG fluxes. Here we determined the effect of RCG cultivation on GHG emission from peatland rewetted to various extents. Mesocosms were manipulated to three different ground water levels (GWLs), i.e. 0, -10 and -20 cm below the soil surface in a controlled semi-field facility. Emissions of CO2 (ecosystem respiration, ER), CH4 and N2O from mesocosms with RCG and bare soil were measured at weekly to fortnightly intervals with static chamber techniques for a period of 1 year. Cultivation of RCG increased both ER and CH4 emissions, but decreased the N2O emissions. The presence of RCG gave rise to 69, 75 and 85% of total ER at -20, -10 and 0 cm GWL, respectively. However, this difference was due to decreased soil respiration at the rising GWL as the plant-derived CO2 flux was similar at all three GWLs. For methane, 70-95% of the total emission was due to presence of RCG, with the highest contribution at -20 cm GWL. In contrast, cultivation of RCG decreased N2O emission by 33-86% with the major reductions at -10 and -20 cm GWL. In terms of global warming potential, the increase in CH4 emissions due to RCG cultivation was more than offset by the decrease in N2O emissions at -10 and -20 cm GWL; at 0 cm GWL the CH4 emissions was offset only by 23%. CO2 emissions from ER were obviously the dominant RCG-derived GHG flux, but above-ground biomass yields, and preliminary measurements of gross photosynthetic production, showed that ER could be more than balanced due to the photosynthetic uptake of CO2 by RCG. Our results support that RCG cultivation could be a good land use option in terms of mitigating GHG emission from rewetted peatlands, potentially turning these ecosystems into a sink of atmospheric CO2.

  15. Soil microbial respiration from various microhabitats in Arctic landscape: impact of soil type, environmental conditions and soil age

    NASA Astrophysics Data System (ADS)

    Biasi, Christina; Jokinen, Simo; Marushchak, Maija; Trubnikova, Tatiana; Hämäläinen, Kai; Oinonen, Markku; Martikainen, Pertti

    2014-05-01

    Soil respiration is the second largest C flux between atmosphere and terrestrial ecosystems after gross primary production. Carbon dioxide released from soils is thus a major contributor to the atmospheric CO2 concentration. Despite the global importance, soil respiration and its components (heterotrophic and autotrophic respiration) remain poorly understood and not well constrained fluxes of the terrestrial C cycle. This is particularly true for the Arctic, where huge amounts of the Earth's soil carbon is stored. Here, we report on heterotrophic soil respiration rates from various Arctic tundra microhabitats measured in situ. The study site was Seida (67°07'N, 62°57'E, 100 m a.s.l.) which is characterized by typical sub-arctic permafrost landscape which comprises raised, vegetated permafrost peat plateaus, interspersed with spots of bare peat surfaces (peat circles), and upland mineral soils. We used isotope partitioning approach based on differences in natural abundance of 14C between soil and plants to separate sources of soil-respired CO2. In addition, the tradition trenching approach was employed. Complementary laboratory incubations with homogenized soil were conducted to assess primary decomposability of the soils and to identify age of the CO2 released and thus get more information on the nature of the sources of respiration. The major aim was to link SMR rates with of soil type, land cover class, soil physic-chemical properties (e.g. water content), soil C stocks and age of soil. Results show that, despite profound differences in soil characteristics and primary decomposability of organic matter, surface CO2 fluxes derived from soil microbial respiration rates were rather similar between microhabitats. The only factor which influenced, at least to some extent, the respiration rates was total soil C (and N) stocks in surface soils. There was some evidence for reduced soil-related CO2 emissions from peatlands, though results were not consistent between the methods applied. It seems that the lower decomposability of peat is largely outweighed by higher C stocks at field conditions. Surprisingly, the bare surfaces (peat circles) with 3500 years old C at the surface exhibited about the largest soil microbial respiration rates among all sites as shown by both methods. This is likely due to the immature status of the peat which was during the bulk of its developmental time protected by permafrost, together with high C-densities. The observation is particularly relevant for decomposition of deeper peat at the permafrost-active layer interface in the large vegetated peat plateaus, where soil material similar to the bare surfaces can be found. The results suggest that the chemical nature and high age of the soil SOC in deep peat does not solely guarantee for resistance to decay. Thus, the study highlights risks for potential re-mobilization of C in deep peat soils following thawing. Soil microbial respiration rates need to be better known when predicting the overall carbon sink/source character of tundra ecosystems in a warming climate. Biasi C., Jokinen S., Marushchak M., Hämäläinen K., Trubnikova T., Oinonen M., Martikainen P. (2013). Microbial respiration in Arctic upland and peat soils as source of CO2. Ecosystems. DOI: 10.1007/s10021-013-9710-z.

  16. A Greener Arctic: Vascular Plant Litter Input in Subarctic Peat Bogs Changes Soil Invertebrate Diets and Decomposition Patterns

    NASA Astrophysics Data System (ADS)

    Krab, E. J.; Berg, M. P.; Aerts, R.; van Logtestijn, R. S. P.; Cornelissen, H. H. C.

    2014-12-01

    Climate-change-induced trends towards shrub dominance in subarctic, moss-dominated peatlands will most likely have large effects on soil carbon (C) dynamics through an input of more easily decomposable litter. The mechanisms by which this increase in vascular litter input interacts with the abundance and diet-choice of the decomposer community to alter C-processing have, however, not yet been unraveled. We used a novel 13C tracer approach to link invertebrate species composition (Collembola), abundance and species-specific feeding behavior to C-processing of vascular and peat moss litters. We incubated different litter mixtures, 100% Sphagnum moss litter, 100% Betula leaf litter, and a 50/50 mixture of both, in mesocosms for 406 days. We revealed the transfer of C from the litters to the soil invertebrate species by 13C labeling of each of the litter types and assessed 13C signatures of the invertebrates Collembola species composition differed significantly between Sphagnum and Betula litter. Within the 'single type litter' mesocosms, Collembola species showed different 13C signatures, implying species-specific differences in diet choice. Surprisingly, the species composition and Collembola abundance changed relatively little as a consequence of Betula input to a Sphagnum based system. Their diet choice, however, changed drastically; species-specific differences in diet choice disappeared and approximately 67% of the food ingested by all Collembola originated from Betula litter. Furthermore, litter decomposition patterns corresponded to these findings; mass loss of Betula increased from 16.1% to 26.2% when decomposing in combination with Sphagnum, while Sphagnum decomposed even slower in combination with Betula litter (1.9%) than alone (4.7%). This study is the first to empirically show that collective diet shifts of the peatland decomposer community from mosses towards vascular plant litter may drive altered decomposition patterns. In addition, we showed that although species-specific differences in Collembola feeding behavior appear to exist, species are very plastic in their diet. This implies that changes in C turnover rates with vegetation shifts, might well be due to diet shifts of the present decomposer community rather than by changes in species composition.

  17. Changes in the salinity of solonetzic soil complexes of the Ergeni Upland under long-term anthropogenic impact (soil studies at the Arshan'-Zel'men Experimental Station of the Russian Academy of Sciences)

    NASA Astrophysics Data System (ADS)

    Novikova, A. F.; Gabchenko, M. V.; Bespalov, V. P.

    2009-04-01

    Unique experiments performed since the 1950s at the Arshan’-Zel’men Experimental Station have formed the basis for afforestation in the dry steppe and semidesert zone without irrigation on the salt-affected soils of solonetzic soil complexes of the Ergeni Upland. Ameliorative measures favored the accumulation of productive moisture in the upper 2-m-thick soil layer, which ensured the growth of trees and the partial leaching of soluble salts to a depth of 1-1.4 m. However, no complete desalinization of the soil profiles took place. The degree of removal of exchangeable sodium from the exchange complex (soil dealkalization) was smaller. The monitoring of changes in the salt status of the soils upon agroforest reclamation was performed until the early 1980s. Our investigations of 2005-2006 showed that the soil amelioration is still in progress: the salt maximum in the profile of the solonetzes descended to a depth of 2.2 m, and the exchangeable sodium was lost from the plow layer (0-40 cm). Plowed soils between forest shelterbelts were also subjected to desalinization and dealkalization of their soil profile, though less intensely than those under the shelterbelts.

  18. Instrumenting an upland research catchment in Canterbury, New Zealand to study controls on variability of soil moisture, shallow groundwater and streamflow

    NASA Astrophysics Data System (ADS)

    McMillan, Hilary; Srinivasan, Ms

    2015-04-01

    Hydrologists recognise the importance of vertical drainage and deep flow paths in runoff generation, even in headwater catchments. Both soil and groundwater stores are highly variable over multiple scales, and the distribution of water has a strong control on flow rates and timing. In this study, we instrumented an upland headwater catchment in New Zealand to measure the temporal and spatial variation in unsaturated and saturated-zone responses. In NZ, upland catchments are the source of much of the water used in lowland agriculture, but the hydrology of such catchments and their role in water partitioning, storage and transport is poorly understood. The study area is the Langs Gully catchment in the North Branch of the Waipara River, Canterbury: this catchment was chosen to be representative of the foothills environment, with lightly managed dryland pasture and native Matagouri shrub vegetation cover. Over a period of 16 months we measured continuous soil moisture at 32 locations and near-surface water table (< 2 m) at 14 locations, as well as measuring flow at 3 stream gauges. The distributed measurement sites were located to allow comparisons between North and South facing locations, near-stream versus hillslope locations, and convergent versus divergent hillslopes. We found that temporal variability is strongly controlled by the climatic seasonal cycle, for both soil moisture and water table, and for both the mean and extremes of their distributions. Groundwater is a larger water storage component than soil moisture, and the difference increases with catchment wetness. The spatial standard deviation of both soil moisture and groundwater is larger in winter than in summer. It peaks during rainfall events due to partial saturation of the catchment, and also rises in spring as different locations dry out at different rates. The most important controls on spatial variability are aspect and distance from stream. South-facing and near-stream locations have higher water tables and more, larger soil moisture wetting events. Typical hydrological models do not explicitly account for aspect, but our results suggest that it is an important factor in hillslope runoff generation. Co-measurement of soil moisture and water table level allowed us to identify interrelationships between the two. Locations where water tables peaked closest to the surface had consistently wetter soils and higher water tables. These wetter sites were the same across seasons. However, temporary patterns of strong soil moisture response to summer storms did not correspond to the wetter sites. Total catchment spatial variability is composed of multiple variability sources, and the dominant type is sensitive to those stores that are close to a threshold such as field capacity or saturation. Therefore, we classified spatial variability as 'summer mode' or 'winter mode'. In summer mode, variability is controlled by shallow processes e.g. interactions of water with soils and vegetation. In winter mode, variability is controlled by deeper processes e.g. groundwater movement and bypass flow. Double flow peaks observed during some events show the direct impact of groundwater variability on runoff generation. Our results suggest that emergent catchment behaviour depends on the combination of these multiple, time varying components of variability.

  19. Utilization of subsurface microbial electrochemical systems to elucidate the mechanisms of competition between methanogenesis and microbial iron(III)/humic acid reduction in Arctic peat soils

    NASA Astrophysics Data System (ADS)

    Friedman, E. S.; Miller, K.; Lipson, D.; Angenent, L. T.

    2012-12-01

    High-latitude peat soils are a major carbon reservoir, and there is growing concern that previously dormant carbon from this reservoir could be released to the atmosphere as a result of continued climate change. Microbial processes, such as methanogenesis and carbon dioxide production via iron(III) or humic acid reduction, are at the heart of the carbon cycle in Arctic peat soils [1]. A deeper understanding of the factors governing microbial dominance in these soils is crucial for predicting the effects of continued climate change. In previous years, we have demonstrated the viability of a potentiostatically-controlled subsurface microbial electrochemical system-based biosensor that measures microbial respiration via exocellular electron transfer [2]. This system utilizes a graphite working electrode poised at 0.1 V NHE to mimic ferric iron and humic acid compounds. Microbes that would normally utilize these compounds as electron acceptors donate electrons to the electrode instead. The resulting current is a measure of microbial respiration with the electrode and is recorded with respect to time. Here, we examine the mechanistic relationship between methanogenesis and iron(III)- or humic acid-reduction by using these same microbial-three electrode systems to provide an inexhaustible source of alternate electron acceptor to microbes in these soils. Chamber-based carbon dioxide and methane fluxes were measured from soil collars with and without microbial three-electrode systems over a period of four weeks. In addition, in some collars we simulated increased fermentation by applying acetate treatments to understand possible effects of continued climate change on microbial processes in these carbon-rich soils. The results from this work aim to increase our fundamental understanding of competition between electron acceptors, and will provide valuable data for climate modeling scenarios. 1. Lipson, D.A., et al., Reduction of iron (III) and humic substances plays a major role in anaerobic respiration in an Arctic peat soil. Journal of Geophysical Research-Biogeosciences, 2010. 115. 2. Friedman, E.S., et al., A cost-effective and field-ready potentiostat that poises subsurface electrodes to monitor bacterial respiration. Biosensors and Bioelectronics, 2012. 32(1): p. 309-313.

  20. Sequence composition of BAC clones and SSR markers mapped to Upland cotton chromosomes 11 and 21 targeting resistance to soil-borne pathogens

    PubMed Central

    Wang, Congli; Ulloa, Mauricio; Shi, Xinyi; Yuan, Xiaohui; Saski, Christopher; Yu, John Z.; Roberts, Philip A.

    2015-01-01

    Genetic and physical framework mapping in cotton (Gossypium spp.) were used to discover putative gene sequences involved in resistance to common soil-borne pathogens. Chromosome (Chr) 11 and its homoeologous Chr 21 of Upland cotton (G. hirsutum) are foci for discovery of resistance (R) or pathogen-induced R (PR) genes underlying QTLs involved in response to root-knot nematode (Meloidogyne incognita), reniform nematode (Rotylenchulus reniformis), Fusarium wilt (Fusarium oxysporum f.sp. vasinfectum), Verticillium wilt (Verticillium dahliae), and black root rot (Thielaviopsis basicola). Simple sequence repeat (SSR) markers and bacterial artificial chromosome (BAC) clones from a BAC library developed from the Upland cotton Acala Maxxa were mapped on Chr 11 and Chr 21. DNA sequence through Gene Ontology (GO) of 99 of 256 Chr 11 and 109 of 239 Chr 21 previously mapped SSRs revealed response elements to internal and external stimulus, stress, signaling process, and cell death. The reconciliation between genetic and physical mapping of gene annotations from new DNA sequences of 20 BAC clones revealed 467 (Chr 11) and 285 (Chr 21) G. hirsutum putative coding sequences, plus 146 (Chr 11) and 98 (Chr 21) predicted genes. GO functional profiling of Unigenes uncovered genes involved in different metabolic functions and stress response elements (SRE). Our results revealed that Chrs 11 and 21 harbor resistance gene rich genomic regions. Sequence comparisons with the ancestral diploid D5 (G. raimondii), A2 (G. arboreum) and domesticated tetraploid TM-1 AD1 (G. hirsutum) genomes revealed abundance of transposable elements and confirmed the richness of resistance gene motifs in these chromosomes. The sequence information of SSR markers and BAC clones and the genetic mapping of BAC clones provide enhanced genetic and physical frameworks of resistance gene-rich regions of the cotton genome, thereby aiding discovery of R and PR genes and breeding for resistance to cotton diseases. PMID:26483808

  1. Sequence composition of BAC clones and SSR markers mapped to Upland cotton chromosomes 11 and 21 targeting resistance to soil-borne pathogens.

    PubMed

    Wang, Congli; Ulloa, Mauricio; Shi, Xinyi; Yuan, Xiaohui; Saski, Christopher; Yu, John Z; Roberts, Philip A

    2015-01-01

    Genetic and physical framework mapping in cotton (Gossypium spp.) were used to discover putative gene sequences involved in resistance to common soil-borne pathogens. Chromosome (Chr) 11 and its homoeologous Chr 21 of Upland cotton (G. hirsutum) are foci for discovery of resistance (R) or pathogen-induced R (PR) genes underlying QTLs involved in response to root-knot nematode (Meloidogyne incognita), reniform nematode (Rotylenchulus reniformis), Fusarium wilt (Fusarium oxysporum f.sp. vasinfectum), Verticillium wilt (Verticillium dahliae), and black root rot (Thielaviopsis basicola). Simple sequence repeat (SSR) markers and bacterial artificial chromosome (BAC) clones from a BAC library developed from the Upland cotton Acala Maxxa were mapped on Chr 11 and Chr 21. DNA sequence through Gene Ontology (GO) of 99 of 256 Chr 11 and 109 of 239 Chr 21 previously mapped SSRs revealed response elements to internal and external stimulus, stress, signaling process, and cell death. The reconciliation between genetic and physical mapping of gene annotations from new DNA sequences of 20 BAC clones revealed 467 (Chr 11) and 285 (Chr 21) G. hirsutum putative coding sequences, plus 146 (Chr 11) and 98 (Chr 21) predicted genes. GO functional profiling of Unigenes uncovered genes involved in different metabolic functions and stress response elements (SRE). Our results revealed that Chrs 11 and 21 harbor resistance gene rich genomic regions. Sequence comparisons with the ancestral diploid D5 (G. raimondii), A2 (G. arboreum) and domesticated tetraploid TM-1 AD1 (G. hirsutum) genomes revealed abundance of transposable elements and confirmed the richness of resistance gene motifs in these chromosomes. The sequence information of SSR markers and BAC clones and the genetic mapping of BAC clones provide enhanced genetic and physical frameworks of resistance gene-rich regions of the cotton genome, thereby aiding discovery of R and PR genes and breeding for resistance to cotton diseases. PMID:26483808

  2. Effects of Winter Flooding Peat Soils on Greenhouse Gas Emissions in the Sacramento-San Joaquin Delta

    NASA Astrophysics Data System (ADS)

    Anderson, F. E.; Pellerin, B. A.; Bergamaschi, B. A.; Sturtevant, C. S.; Verfaillie, J. G.; Knox, S. H.; Baldocchi, D. D.; Fujii, R.

    2013-12-01

    Harvested cornfields make up nearly 80% of cropland intentionally flooded during the winter (October through February) in the Sacramento-San Joaquin Delta to support waterfowl migration along the Pacific Flyway. This area is characterized by peat-rich islands that when flooded have the potential to be a source of methane production and emission, while reducing carbon dioxide respiration. Given the extent of winter flooding in the Delta, we evaluated the greenhouse gas emissions during this period and compared it to conventional winter fallow management. We constructed two eddy covariance towers on Staten Island, one in a cornfield flooded during the winter and the other one in a reference cornfield that remains fallow. Each tower included measurements of carbon dioxide, latent, sensible, and ground heat fluxes, as well as a suite of radiation measurements. A LI-COR Open Path Methane Analyzer (LI-7700) was initially installed at the flooded site and then alternated between the two sites every three to four weeks throughout the study. A second LI-7700 was deployed for continuous measurements at both towers in the winter of 2012/2013. Both fields have been under the same management for growing corn in the summer for the past twenty-five years. After harvest, the residual corn is chopped and then tilled into the soil before the winter season. Methane emissions slowly increased during the winter flooded period in 2011-2012, with maximum emissions (~234 mg-C m-2 day-1) occurring immediately following field drainage in mid-February. Methane emissions during the second winter period (e.g. 2012-2013) were similar to the first season in magnitude and timing, but showed two distinct events where emissions slowly increased followed by a maximum emission pulse and then a rapid decrease. Preliminary data analysis suggests the influence of strong Pacific storms occurring in the beginning of the second flooded season as a source of disturbance and agitating mechanism leading to elevated methane emissions. Carbon dioxide fluxes showed that carbon was sequestered during the summer growing season (~10 g-C m-2 day-1), as observed in other agricultural settings, followed by relatively low rates of respired carbon dioxide during the fallow/flooded season (~0 to 5 g-C m-2 day-1). Our results indicate that intentional winter flooding increases methane emissions relative to the non-flooded conditions. However, the magnitude of the increase requires consideration in the context of benefits from flooding and water management strategies for waterfowl migration and potential reduction in carbon dioxide fluxes during the flooded period.

  3. Use of Computed Tomography Imaging for Qualifying Coarse Roots, Rhizomes, Peat, and Particle Densities in Marsh Soils

    EPA Science Inventory

    Computed tomography (CT) imaging has been used to describe and quantify subtidal, benthic animals such as polychaetes, amphipods, and shrimp. Here, for the first time, CT imaging is used to successfully quantify wet mass of coarse roots, rhizomes, and peat in cores collected from...

  4. Morphology, morphogenesis and molecular phylogeny of a novel soil ciliate, Pseudouroleptus plestiensis n. sp. (Ciliophora, Oxytrichidae), from the uplands of Colfiorito, Italy.

    PubMed

    Bharti, Daizy; Kumar, Santosh; La Terza, Antonietta

    2014-08-01

    The terrestrial oxytrichid ciliate Pseudouroleptus plestiensis n. sp., isolated from soil samples collected from the uplands of Colfiorito (Umbria region, Italy), was investigated using live observation and protargol impregnation. The morphology, morphogenesis and molecular phylogeny inferred from small-subunit (SSU) rRNA gene sequences were studied. The novel species is mainly characterized by the following: a cell size of about 14535 m in vivo; two ellipsoidal macronuclear nodules and two to four micronuclei; adoral zone about 26% of body length with a mean of 30 membranelles; about 40 cirri in the right marginal row and 38 in the left marginal row; left fronto-ventral row consisting of about 27-40 cirri, right fronto-ventral row of about three to seven cirri forming a short row to the right of the rear portion of the left fronto-ventral row; one parabuccal cirrus (?=?III/2), one buccal and one post-peristomial cirrus; and four dorsal kineties with caudal cirri at the end of kineties 1 and 2. The morphogenesis of the novel species is similar to that of Pseudouroleptus caudatus. Phylogenetic analyses based on SSU rRNA gene sequences consistently placed the novel species within the family Oxytrichidae Ehrenberg, 1838, clustering with P. caudatus and the genus Strongylidium. The results from the present study contribute to the expanding knowledge of the diversity of ciliates in Italian soil. PMID:24824635

  5. [Influence of paddy rice-upland crop rotation of cold-waterlogged paddy field on crops produc- tion and soil characteristics].

    PubMed

    Wang, Fei; Li, Qing-hua; Lin, Cheng; He, Chun-mei; Zhong, Shao-jie; Li, Yu; Lin, Xin-jian; Huang, Jian-cheng

    2015-05-01

    Two consecutive years (4-crop) experiments were conducted to study the influence of different paddy rice-upland crop rotation in cold-waterlogged paddy field on the growth of crops and soil characteristics. The result showed that compared with the rice-winter fallow (CK) pattern, the two-year average yield of paddy rice under four rotation modes, including rape-rice (R-R), spring corn-rice (C-R), Chinese milk vetch-rice (M-R) and bean-rice (B-R), were increased by 5.3%-26.7%, with significant difference observed in C-R and R-R patterns. Except for M-R pattern, the annual average total economic benefits were improved by 79.0%-392.4% in all rotation pattern compared with the CK, and the ration of output/input was enhanced by 0.06-0.72 unit, with the most significant effect found in the C-R pattern. Likewise, compared with the CK, the contents of chlorophyll and carotenoid, and net photosynthetic rate (Pn) of rice plant were all increased during the full-tillering stage of rice in all rotation patterns. The rusty lines and rusty spots of soils were more obvious compared with the CK during the rice harvest, particularly in R-R, C-R and B-R patterns. The ratio of water-stable soil macro aggregates of plough layer of soil (> 2 mm) decreased at different levels in all rotation patterns while the ratios of middle aggregate (0.25-2 mm, expect for M-R) and micro aggregate of soil (< 0.25 mm) were opposite. There was a decreasing trend for soil active reducing agents in all rotation patterns, whereas the available nutrient increased. The amounts of soil bacteria in C-R and B-R patterns, fungi in B-R rotation pattern, cellulose bacteria in R-R, C-R and B-R patterns and N-fixing bacteria in B-R pattern were improved by 285.7%-403.0%, 221.7%, 64.6-92.2% and 162.2%, respectively. Moreover, the differences in all microorganisms were significant. Thus, based on the experimental results of cold-waterlogged paddy field, it was concluded that changing from single cropping rice system to C-R, R-R and B-R rotation patterns had good effect in terms of improving total yield and economic benefits, and soil physical and chemical properties were improved. PMID:26571667

  6. Diagnostics of hydromorphism in soils of autonomous positions on the Severo-Sos'vinsk Upland (Western Siberia)

    NASA Astrophysics Data System (ADS)

    Avetov, N. A.; Sopova, E. O.; Golovleva, Yu. A.; Kiryushin, A. V.; Krasilnikov, P. V.

    2014-11-01

    The complex studies of hydromorphism features in taiga weakly differentiated soils using morphological (color), chemical (iron content in different extracts, indicators of reducing conditions (IRIS)), and geobotanic (using the Ramenskii scale) methods have led to ambiguous conclusions. In all the soils, surface gleying was manifested. According to the results obtained by different methods, the maximum reduction processes were related to either the sublitter or the next deeper horizon. The Schwertmann coefficient, the criterion of Bodegom, and the Ramenskii scale indicated an increase of hydromorphism in the soils studied in the following sequence: the lower part of the ridge slopes drained by the small gullies < the middle part of the slopes < the flat tops of the ridges < the depression between the ridges. The morphological diagnostics of gleying proved to be a less sensitive method, which can recognize only the most contrasting hydromorphic soils. The lower horizons in some taiga soils have a bluish gray color probably not related to the recent soil hydromorphism.

  7. Compositional changes in soil water and runoff water following managed burning on a UK upland blanket bog

    NASA Astrophysics Data System (ADS)

    Clay, Gareth D.; Worrall, Fred; Fraser, Evan D. G.

    2010-01-01

    SummaryThis study examines the effect managed rotational burning has on soil water and runoff water compositions at the end of a 10 year burning cycle and into the year following a managed burn. This study includes aluminium, iron, calcium, sodium, magnesium, potassium, sulphate, chloride, bromide, fluoride, phosphate and nitrate along with pH, conductivity and DOC. The main findings of this study are: The presence of burning leads to lower concentrations of species associated with deep water sources in both soil and runoff waters. Following burning, soil water has increased concentrations in shallow soil water components (i.e. Al, Fe). Conversely runoff water shows a decrease in the concentration of shallow water components Principal component analysis shows that in the post-burn period, soil water is less mixed with rainwater and runoff water becomes more rainwater-like in composition, i.e. compositions of soil and runoff have diverged as a result of the burn.

  8. Litter decomposition and nitrogen and phosphorus dynamics in peatlands and uplands over 12 years in central Canada.

    PubMed

    Moore, Tim R; Trofymow, J A; Siltanen, M; Kozak, L M

    2008-08-01

    The large accumulation of organic matter in peatlands has been partially attributed to litter decomposition rates, which are slowed by a high water table. To test this, we examined whether there were significant differences in the decomposition and N and P dynamics of ten foliar litters and wood blocks at three pairs of upland forest and peatland sites in the transitional grassland, high boreal and low subarctic regions of central Canada, using litterbags collected over a 12-year period. At two of the three pairs, the decomposition rate, as determined by proportion of the original mass remaining after 12 years and by the exponential decay coefficient (k), was faster overall at the upland than at the peatland. In the third pair, there was no significant difference, despite the water table being close to the peat surface; warmer soil temperatures in the peatland than the upland may be the cause. In general, there were small losses or gains of N in the litters after 12 years, compared to the original litter, though there were some differences among litter types and sites, net gains in N likely reflecting the higher exogenous N availability. P was lost from most litters at the two northern pairs of sites, but at the transitional grassland pair, there were large net gains in P and greater variation among litters. The N:P ratio in the original litters ranged from 5 to 26 and after 12 years the ratio narrowed, with the site average of the ten litters ranging from 13 to 22, varying with the soil ratio. Decomposition rates and N and P dynamics after 12 years are different between upland and peatland sites: although the water table is a primary control on these differences, other factors such as temperature and soil nutrient status are also important. PMID:18560899

  9. 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.; Fu, 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 "Groes 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, values are interpolated on a 0.5 hour scale between measurement campaigns. In combination with continually logged meteorological parameters, such as the photosynthetic active radiation as well as air and soil temperatures, we calculate the daily CO2 ecosystem exchange of the different sites. During the 2011 campaign, CO2 was determined as the most important greenhouse gas. The groundwater table was the dominant variable influencing gas emissions. Another important factor was the vegetation composition. In detail, highest CO2 emissions occurred with a water table of 40-50 cm below ground level, temperatures above 10C and low plant biomass amounts. Due to the more complex formation of N2O by a number of processes, each being promoted by different soil conditions, the measurement of N2O fluxes in the field was complemented by a laboratory experiment. In this, the use of stable isotope tracer techniques enabled us to quantify the contribution of single biochemical pathways to the overall formation of N2O under controlled conditions. This together with the prediction of the systems CO2 exchange, gives valuable information on how degraded peatlands can be restored best or at least be cultivated in a way to achieve climate neutral conditions. Thus, our study improves the prediction, how peatland soils will react to changes of soil and climate conditions with respect to their greenhouse gas emissions.

  10. Lower variability of radionuclide activities in upland dairy products compared to soils and vegetation: implication for environmental survey.

    PubMed

    Pourcelot, L; Steinmann, P; Froidevaux, P

    2007-01-01

    Contamination of the environment by radionuclides is usually estimated using soil and grass sampling. However, radionuclides are often not homogeneously distributed in soils. In the alpine Mercantour region (Western Alps, France) a large heterogeneity in Chernobyl 137Cs deposition has been previously observed. Here we report additional 137Cs results together with new 90Sr and Pu data for soil, grass, milk, and cheese samples. The results show that radioisotopes from nuclear weapons tests fallout are more homogeneously distributed than Chernobyl 137Cs. Further, we observe that the 137Cs and 90Sr contents are less variable in milk samples than in grass or soil samples. This can be attributed to the homogenization effect of cow vagrancy during grazing. Hence milk seems to be a more robust sample than soil or grass to evaluate the extent of contamination on a regional scale. We explore this idea by comparing own unpublished 90Sr results and 90Sr results from the literature to establish the relationship between altitude of grazing and contamination of soil and milk for Western Europe. There is a significant positive correlation between soil contamination and altitude and an even closer correlation between milk 90Sr activity (A) and altitude (h): A = A0 + e(k x h) where A0 is the expected activity of milk sampled at sea level (A0 = 0.064 +/- 0.014 Bq g(-1) Ca) and h is the altitude of grazing, k being a constant (k = 0.95 x 10(-3) +/- 0.11 x 10(-3) m(-1) Bq g(-1) Ca). The fact that there is less scattering in the relationship for the 90Sr(milk)-altitude than for 90Sr(soil)-altitude suggests, again, that milk is a well-suited sample for environmental survey. The relationship between the altitude of grazing and the 90Sr content of milk and cheese can also be used to assess the authenticity of dairy products. PMID:17005236

  11. Nitrate turnover in a peat soil under drained and rewetted conditions: results from a [(15)N]nitrate-bromide double-tracer study.

    PubMed

    Russow, Rolf; Tauchnitz, Nadine; Spott, Oliver; Mothes, Sibylle; Bernsdorf, Sabine; Meissner, Ralph

    2013-01-01

    Under natural conditions, peatlands are generally nitrate-limited. However, recent concerns about an additional N input into peatlands by atmospheric N deposition have highlighted the risk of an increased denitrification activity and hence the likelihood of a rise of emissions of the greenhouse gas nitrous oxide. Therefore, the aim of the present study was to investigate the turnover of added nitrate in a drained and a rewetted peatland using a [(15)N]nitrate-bromide double-tracer method. The double-tracer method allows a separation between physical effects (dilution, dispersion and dislocation) and microbial and chemical nitrate transformation by comparing with the conservative Br(-) tracer. In the drained peat site, low NO3(-) consumption rates have been observed. In contrast, NO3(-) consumption at the rewetted peat site rises rapidly to about 100% within 4 days after tracer application. Concomitantly, the (15)N abundances of nitrite and ammonium in soil water increased and lead to the conclusion that, besides commonly known NO3(-) reduction to nitrite (i.e. denitrification), a dissimilatory nitrate reduction to ammonium has simultaneously taken place. The present study reveals that increasing NO3(-) inputs into rewetted peatlands via atmospheric deposition results in a rapid NO3(-) consumption, which could lead to an increase in N2O emissions into the atmosphere. PMID:24313368

  12. Metals in the soils of a small watershed in the forest-steppe zone of the central Russian upland

    NASA Astrophysics Data System (ADS)

    Samonova, O. A.; Gennadiev, A. N.; Koshovskii, T. S.; Zhidkin, A. P.

    2015-06-01

    The spatial distributions of Mn, Cu, Ni, Co, Cr, Zn, Pb, Mo, Ti, Zr, and Fe, as well as particle sizes and humus, in the surface horizon of soils in the Lokna River small watershed (Tula oblast) have been studied. The relationships of the studied parameters have been characterized by statistical methods. Little change in particle size distribution in the humus horizons of soils is revealed from the geomorphological elements of the watershed. An increase in the content of most metals is observed in soils on the convex slopes and the bottom of the watershed balka compared to the autonomous positions. Positive correlations have been found between the contents of Co, Mn, Zr, Mo, and, to a lesser degree, Zn and Pb and the sand and coarse silt fractions; no correlations of Ni, Cr, Ti, and Fe with the particle size fractions were revealed.

  13. Influence of Soil Structure, Pore-Water Pressure, and Tailwater Height on Headcut Migration in Upland Concentrated Flows

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Soil loss from arable fields caused by surface runoff erosion is composed of several components due to different erosion processes. Bennett et al. (2000) reported experimental data showing that actively migrating ephemeral-gully headcuts display steady-state migration and self-similar organization i...

  14. 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.

  15. Influence of hydrological connectivity on water, carbon and thermal dynamics in peat-dominated catchments

    NASA Astrophysics Data System (ADS)

    Dick, Jonathan; Tetzlaff, Doerthe; Soulsby, Chris

    2013-04-01

    Extended peatlands are characteristic of many upland catchments. Peaty soils in riparian zones are an important interface between subsurface, terrestrial and aquatic environments that can regulate hydrological and biogeochemical fluxes between the hillslope and stream. This buffering potential is spatially and temporally variable due to both horizontal and vertical subsurface heterogeneity within the riparian area and is linked to soil type, hydrology and biogeochemical processes. It is important to understand how this heterogeneity affects the connectivity between landscapes and the river network and how this interacts with variability in hydrology, stream water quality and ecosystem function. Here, we present high resolution monitoring of dissolved organic carbon (DOC), dissolved oxygen concentrations (DO) and spatially distributed water temperature data from a 3.2 km2 upland watershed in the NE Scottish Highlands. This data will be coupled to understand how temporal and spatial variation in the connectivity of the riparian peat wetlands and the stream network modulates stream water chemistry and its thermal fingerprint. This potential to regulate water quality is deeply rooted in the different hydrological flow paths and stores water takes prior to entering stream flow. Initial results indicate a seasonally varying link between runoff and DOC, with lower base flows generally having lowest concentrations. Over the course of high-flow events, concentrations are high but decrease rapidly as the soils are depleted of DOC. Replenishment by subsurface biological processes occurs at short time scales in summer. Stream water temperature profiles show distinct differences in drivers with varying flow conditions; temperatures during low flows suggest strong atmospheric controls whereas during high flows an increasing influx of groundwater is evident. Furthermore, the dissolved oxygen data are used in modelling the stream metabolism to assess the eco-hydrological response of the catchment to hydroclimatic variability to further the understanding of how changing climate will impact upon aquatic ecosystem function in peatland dominated upland catchments.

  16. Coupling of groundwater, river flow and rainfall in an upland floodplain

    NASA Astrophysics Data System (ADS)

    Archer, Nicole; Dochartaigh, Brighid .; MacDonald, Alan; Bonell, Mike; Black, Andrew; Coles, Neil

    2014-05-01

    Upland floodplains provide an important function in regulating river flows and controlling the coupling of hillslope runoff with rivers. To investigate the responses of floodplain groundwater to river flows and rainfall events, a small floodplain in an upland area of the River Tweed catchment, Scotland, was characterised using geophysics, 3D geological mapping and hydrogeological testing; and monitoring undertaken from September 2011 to February 2013 of: groundwater levels in five pairs of piezometers; river stage and flow at the upstream and downstream limits of the study site; soil moisture on the adjacent hillslope; and meteorological parameters. Periodical groundwater chemistry and residence data were also collected. The floodplain aquifer is permeable throughout but partially stratified, comprising dominantly alluvial and glaciofluvial sandy gravels between 8 and 15m interspersed with thin, intermittent layers of low permeability silts, clays and peats. Overlying the gravel aquifer is a partial thin cover of low permeability alluvial silts, and it is underlain dominantly by low permeability glaciolacustrine silts and clays. High permeability solifluction deposits mantle much of the adjacent hillslope and provide a rapid connection to the floodplain aquifer. The unusually wet year of 2012 provides a good example of how a temperate upland floodplain responds to consistently high rainfall. Statistical analysis and graphical interpretation of groundwater level, rainfall, soil moisture and river stage demonstrates that: 1) dominant groundwater flow within the floodplain is in the same direction as the river, from up-valley to down-valley; 2) soil moisture in the hillslope is strongly correlated with local rainfall, but groundwater across much of the floodplain is more strongly influenced by river stage; except 3) groundwater near the edge of floodplain, which responds more slowly to local rainfall and river stage changes ; and 4) subsurface flow from the hillslope to the floodplain occurs during high rainfall events. A detailed investigation of three flood events, when the river rose above bank level and flooded adjacent fields and groundwater became artesian in parts of the floodplain, suggests that antecedent moisture conditions can partly explain the differences in groundwater response during different flood events, where high intensity or long duration rainfall can cause saturated soil conditions, reducing soil water storage capacity and hence promoting flood conditions. A conceptual model based on field data of groundwater flow after storm events during antecedent unsaturated and saturated soil conditions is presented.

  17. Newly Isolated Paenibacillus tyrfis sp. nov., from Malaysian Tropical Peat Swamp Soil with Broad Spectrum Antimicrobial Activity.

    PubMed

    Aw, Yoong-Kit; Ong, Kuan-Shion; Lee, Learn-Han; Cheow, Yuen-Lin; Yule, Catherine M; Lee, Sui-Mae

    2016-01-01

    Emergence of antimicrobial resistance coupled with the slowdown in discovery of new antimicrobial compounds points to serious consequences for human health. Therefore, scientists are looking for new antimicrobial compounds from unique and understudied ecosystems such as tropical peat swamp forests. Over the course of isolating antimicrobial producing bacteria from North Selangor tropical peat swamp forest, Malaysia, a Gram variable, rod shaped, endospore forming, facultative anaerobic novel strain MSt1(T) that exerts potent and broad spectrum antimicrobial activity was isolated. Phylogenetic analysis using 16S rRNA gene sequences showed that strain MSt1(T) belonged to the genus Paenibacillus with the highest similarity to Paenibacillus elgii SD17(T) (99.5%). Whole genome comparison between strain MSt1(T) with its closely related species using average nucleotide identity (ANI) revealed that similarity between strain MSt1(T) with P. elgii B69 (93.45%) and Paenibacillus ehimensis A2 (90.42%) was below the recommended threshold of 95%. Further analysis using in silico pairwise DDH also showed that similarity between strain MSt1(T) with P. elgii B69 (55.4%) and P. ehimensis A2 (43.7%) was below the recommended threshold of 70%. Strain MSt1(T) contained meso-diaminopilemic acid in the cell wall and MK-7 as the major menaquinone. The major fatty acids of strain MSt1(T) were anteiso-C15:0 (48.2%) and C16:0 (29.0%) whereas the polar lipid profile consisted of phosphatidylglycerol, phosphatidylethanolamine, diphosphatidylglycerol, one unknown lipid, two unknown glycolipids, and one unknown phospholipid. Total DNA G+C content of strain MSt1(T) was 51.5 mol%. The extract from strain MSt1(T) exerted strong antimicrobial activity against Escherichia coli ATCC 25922 (MIC = 1.5 μg/mL), MRSA ATCC 700699 (MIC = 25 μg/mL) and Candida albicans IMR (MIC = 12.5 μg/mL). Partially purified active fraction exerted a strong effect against E. coli ATCC 25922 resulting in cell rupture when viewed with SEM. Based on distinctive taxonomic differences between strain MSt1(T) when compared to its closely related type species, we propose that strain MSt1(T) represents a novel species within the genus of Paenibacillus, for which the name Paenibacillus tyrfis sp. nov. (= DSM 100708(T) = MCCC 1K01247(T)) is proposed. PMID:26973605

  18. Newly Isolated Paenibacillus tyrfis sp. nov., from Malaysian Tropical Peat Swamp Soil with Broad Spectrum Antimicrobial Activity

    PubMed Central

    Aw, Yoong-Kit; Ong, Kuan-Shion; Lee, Learn-Han; Cheow, Yuen-Lin; Yule, Catherine M.; Lee, Sui-Mae

    2016-01-01

    Emergence of antimicrobial resistance coupled with the slowdown in discovery of new antimicrobial compounds points to serious consequences for human health. Therefore, scientists are looking for new antimicrobial compounds from unique and understudied ecosystems such as tropical peat swamp forests. Over the course of isolating antimicrobial producing bacteria from North Selangor tropical peat swamp forest, Malaysia, a Gram variable, rod shaped, endospore forming, facultative anaerobic novel strain MSt1T that exerts potent and broad spectrum antimicrobial activity was isolated. Phylogenetic analysis using 16S rRNA gene sequences showed that strain MSt1T belonged to the genus Paenibacillus with the highest similarity to Paenibacillus elgii SD17T (99.5%). Whole genome comparison between strain MSt1T with its closely related species using average nucleotide identity (ANI) revealed that similarity between strain MSt1T with P. elgii B69 (93.45%) and Paenibacillus ehimensis A2 (90.42%) was below the recommended threshold of 95%. Further analysis using in silico pairwise DDH also showed that similarity between strain MSt1T with P. elgii B69 (55.4%) and P. ehimensis A2 (43.7%) was below the recommended threshold of 70%. Strain MSt1T contained meso-diaminopilemic acid in the cell wall and MK-7 as the major menaquinone. The major fatty acids of strain MSt1T were anteiso-C15:0 (48.2%) and C16:0 (29.0%) whereas the polar lipid profile consisted of phosphatidylglycerol, phosphatidylethanolamine, diphosphatidylglycerol, one unknown lipid, two unknown glycolipids, and one unknown phospholipid. Total DNA G+C content of strain MSt1T was 51.5 mol%. The extract from strain MSt1T exerted strong antimicrobial activity against Escherichia coli ATCC 25922 (MIC = 1.5 μg/mL), MRSA ATCC 700699 (MIC = 25 μg/mL) and Candida albicans IMR (MIC = 12.5 μg/mL). Partially purified active fraction exerted a strong effect against E. coli ATCC 25922 resulting in cell rupture when viewed with SEM. Based on distinctive taxonomic differences between strain MSt1T when compared to its closely related type species, we propose that strain MSt1T represents a novel species within the genus of Paenibacillus, for which the name Paenibacillus tyrfis sp. nov. (= DSM 100708T = MCCC 1K01247T) is proposed. PMID:26973605

  19. Inorganic contents of peats

    SciTech Connect

    Raymond, R. Jr.; Bish, D.L.; Cohen, A.D.

    1988-02-01

    Peat, the precursor of coal, is composed primarily of plant components and secondarily of inorganic matter derived from a variety of sources. The elemental, mineralogic, and petrographic composition of a peat is controlled by a combination of both its botanical and depositional environment. Inorganic contents of peats can vary greatly between geographically separated peat bogs as well as vertially and horizontally within an individual bog. Predicting the form and distribution of inorganic matter in a coal deposit requires understanding the distribution and preservation of inorganic matter in peat-forming environments and diagenetic alterations affecting such material during late-stage peatification and coalification processes. 43 refs., 4 figs., 3 tabs.

  20. Geochemical and Hydrological limitation of carbon sequestration and methane release in anoxic peat soil from the Luther Marsh, Canada

    NASA Astrophysics Data System (ADS)

    Bonaiuti, Simona; Blodau, Christian

    2015-04-01

    In deep peat layers, anaerobic respiration showed a slow-down due to the lack of solute transport which causes an accumulation of metabolic end products (i.e. DIC and CH4). This accumulation can lower the Gibbs free energy levels available to the terminal respiration processes, potentially leading to an inhibition in the decomposition. In particular, this state can affect the methanogenesis, acetogenesis and fermentation processes which occur near thermodynamic minimum energy levels. We conducted a column experiments with an ombrothrophic bog peat over a period of 300 days at 20° C, to test the hypothesis that alteration in solute and gas transport rates can remove this biogeochemical inactivation of DIC and methane turnover rates. To this end, we tested a i) control treatment with no gas and solute transport, ii) advective flow treatment with a flow water of 10 mm d-1, iii) ebullition treatment with methane removal by conduit transport as surrogate for bubbling, and iv) an O2-free atmosphere treatment to test the effect of remote transport of electron on anaerobic decomposition, in absence of oxygen compared to the other treatment. We determined detailed concentration depth profiles of dissolved inorganic carbon (DIC), methane (CH4) and relevant decomposition intermediates (i.e. H2, Fe, nitrate, acetate, formiate and propionate), every 15 days at the beginning and every ca. 2 months after 75 days. CO2 and CH4 fluxes were measured using a static chamber approach. Net turnover of DIC and CH4 in depth layers was calculated for individual depth intervals from mass balance approach based on diffusive mass fluxes between adjacent depth layers and change in storage over time. Thermodynamic energy levels of relevant electron accepting processes were calculated over time. In the initial phase of the experiments, DIC and CH4 concentrations increased mostly below the water table level at 10 cm depth and over time in all treatments. After 45 days of incubation, CH4 concentrations strongly increased in the advective flow treatment, peaked at 70 cm depth with 700 μmol L-1, and in the O2-free treatment, peaked at 20 cm depth with ca. 600 μmol L-1. DIC concentrations after 45 days showed similar pattern in term of levels between the different treatments, showed an increase from ca. 3000 μmol L-1 near the water table to about 5000-6000 μmol L-1at 70-75 cm depth. Furthermore, DIC and methane concentrations in the ebullition treatment showed a decline over time, probably due to the export of gases through the formation of bubbles. At the end of the experiment, we expect that a negative feedback on decomposition will mostly occur in deeper layers in the control treatments due to the slowness of transport and where the accumulation of CO2 and CH4 will be eased, in line with the results presented in previous studies. Keywords: Peatlands; Anaerobic decomposition; Methanogenesis; Net turnover rates; Gas fluxes; Advection; Ebullition.

  1. Evaluating the spatial variation of total mercury in young-of-year yellow perch (Perca flavescens), surface water and upland soil for watershed-lake systems within the southern Boreal Shield

    USGS Publications Warehouse

    Gabriel, M.C.; Kolka, R.; Wickman, T.; Nater, E.; Woodruff, L.

    2009-01-01

    The primary objective of this research is to investigate relationships between mercury in upland soil, lake water and fish tissue and explore the cause for the observed spatial variation of THg in age one yellow perch (Perca flavescens) for ten lakes within the Superior National Forest. Spatial relationships between yellow perch THg tissue concentration and a total of 45 watershed and water chemistry parameters were evaluated for two separate years: 2005 and 2006. Results show agreement with other studies where watershed area, lake water pH, nutrient levels (specifically dissolved NO3--N) and dissolved iron are important factors controlling and/or predicting fish THg level. Exceeding all was the strong dependence of yellow perch THg level on soil A-horizon THg and, in particular, soil O-horizon THg concentrations (Spearman ?? = 0.81). Soil B-horizon THg concentration was significantly correlated (Pearson r = 0.75) with lake water THg concentration. Lakes surrounded by a greater percentage of shrub wetlands (peatlands) had higher fish tissue THg levels, thus it is highly possible that these wetlands are main locations for mercury methylation. Stepwise regression was used to develop empirical models for the purpose of predicting the spatial variation in yellow perch THg over the studied region. The 2005 regression model demonstrates it is possible to obtain good prediction (up to 60% variance description) of resident yellow perch THg level using upland soil O-horizon THg as the only independent variable. The 2006 model shows even greater prediction (r2 = 0.73, with an overall 10??ng/g [tissue, wet weight] margin of error), using lake water dissolved iron and watershed area as the only model independent variables. The developed regression models in this study can help with interpreting THg concentrations in low trophic level fish species for untested lakes of the greater Superior National Forest and surrounding Boreal ecosystem. ?? 2009 Elsevier B.V.

  2. Impact of fire on macropore flow and the hydraulic conductivity of near-surface blanket peat

    NASA Astrophysics Data System (ADS)

    Holden, Joseph; Wearing, Catherine; Palmer, Sheila; Jackson, Benjamin; Johnston, Kerrylyn; Brown, Lee

    2013-04-01

    Peatlands can be subject to wildfire or deliberate burning in many locations. Wildfires are known to impact soil properties and runoff production in most soil types but relatively little work has been conducted on peatlands. Furthermore in large parts of the UK uplands prescribed vegetation burning on peat has taken place at regular intervals (e.g. every 8-25 years) on patches of around 300-900 sq. metres over the past century to support increased grouse populations for sport shooting. However, there have been few studies on how these prescribed fires influence near-surface hydrology. It is known that macropores transport a large proportion of flow in near-surface peat layers and we investigated their role in flow transport for fire sites using tension infiltrometers. Measurements were performed, at replicated hillslope positions to control for slope position effects, on unburnt peat (U) and where prescribed burning had taken place two years (P2), four years (P4) and >15 years (P15+) prior to sampling. For the prescribed burning plots, vegetation burning had also occurred at around a 15-20 year interval for most of the past century. We also sampled a nearby wildfire site (W) with the same sampling design where wildfire had occurred four months prior to sampling. Both the contribution of macropore flow to overall infiltration, and the saturated hydraulic conductivity, were significantly lower in the recently burnt sites (W, P2, P4), compared to P15+ and U. There was no significant difference in macropore flow contributions, effective macroporosity and saturated hydraulic conductivity between P15+ and U. The results suggest fire influences the near-surface hydrological functioning of peatlands but that 'recovery' for some hydrological processes to prescribed vegetation burning may be possible within two decades if there are no further fires.

  3. CO2 Efflux from Cleared Mangrove Peat

    PubMed Central

    Lovelock, Catherine E.; Ruess, Roger W.; Feller, Ilka C.

    2011-01-01

    Background CO2 emissions from cleared mangrove areas may be substantial, increasing the costs of continued losses of these ecosystems, particularly in mangroves that have highly organic soils. Methodology/Principal Findings We measured CO2 efflux from mangrove soils that had been cleared for up to 20 years on the islands of Twin Cays, Belize. We also disturbed these cleared peat soils to assess what disturbance of soils after clearing may have on CO2 efflux. CO2 efflux from soils declines from time of clearing from ∼10 600 tonnes km−2 year−1 in the first year to 3000 tonnes km2 year−1 after 20 years since clearing. Disturbing peat leads to short term increases in CO2 efflux (27 umol m−2 s−1), but this had returned to baseline levels within 2 days. Conclusions/Significance Deforesting mangroves that grow on peat soils results in CO2 emissions that are comparable to rates estimated for peat collapse in other tropical ecosystems. Preventing deforestation presents an opportunity for countries to benefit from carbon payments for preservation of threatened carbon stocks. PMID:21738628

  4. Comment on "Soil CO2, CH4 and N2O fluxes from an afforested lowland raised peat bog in Scotland: implications for drainage and restoration" by Yamulki et al. (2013)

    NASA Astrophysics Data System (ADS)

    Artz, R. R. E.; Chapman, S. J.; Saunders, M.; Evans, C. D.; Matthews, R. B.

    2013-11-01

    Yamulki and co-authors address in their recent publication the important issue of net emissions of greenhouse gases (GHGs) from peatlands where land use conversion has taken place. In their case, they studied conversion to forestry versus peatland restoration after a first rotation of plantation forestry. They monitored soil-derived fluxes of carbon dioxide (CO2), methane (CH4) and nitrous oxide (N2O) using opaque chamber measurements on planted and unplanted control treatments (with or without drainage), and an unplanted plot within a restored (felled) block on former lowland raised bog. They propose that their measurements of greenhouse gas (GHG) emissions at these sites suggest that the total net GHG emissions, in 100 yr carbon dioxide equivalents, of the restored peat bog would be higher than that of the peat bog with trees. We believe there are a number of issues with the measurement, calculation and comparison of these greenhouse budgets that may invalidate this conclusion.

  5. PEAT: an energy alternative

    SciTech Connect

    Schora, F.C.; Punwani, D.V.

    1980-01-01

    Even though peat is a low-heating value and low-bulk density fossil fuel which in its natural state contains over 80 percent moisture, it can be an economical alternative to coal, and fuel oil, as is the case in Iceland and Finland for direct combustion applications. This is because of the relative ease with which peat can be harvested, and the generally low sulfur and ash content of peat. Recent studies show that peat also has very favorable characteristics for conversion to synthetic fuels. Tests show that on the basis of chemistry and kinetics, peat is a better raw material than coal for production of synthetic fuels. Recent estimates also show that conversion of peat to high-Btu gas (>950 Btu/scf) is competitive with other alternatives of synthetic high-Btu gas. Therefore, peat can be an economical energy alternative depending upon location of peat deposits, region of energy need, scale of operation and cost of other energy alternatives.

  6. Peat resource estimation in South Carolina. Final report, Year 2

    SciTech Connect

    Holmes, M.; Andrejko, M.; Corvinus, D.; Tisdale, M.

    1982-01-01

    South Carolina has few indigenous energy resources. Most widely known and utilized are hydropower, wood, and solar. Peat is a material composed of partially decomposed organic matter that, after burial for long periods of time, may eventually become coal. Peat is utilized as an energy resource for the production of electricity and for home heating in Europe and the Soviet Union. There are peat deposits in South Carolina, but peat has never been used as an energy resource within the state. This report presents the results of the two years of a planned four-year study of the quantity and energy potential of peat in South Carolina. In this year's survey two activities were undertaken. The first was to visit highly probable peat deposits to confirm the presence of fuel-grade peat. The second was to survey and characterize in more detail the areas judged to be of highest potential as major resources. The factors carrying the greatest weight in our determination of priority areas were: (1) a description of peat deposits in the scientific literature or from discussions with state and federal soil scientists; (2) mention of organic soils on soil maps or in the literature; and (3) information from farmers and other local citizens.

  7. Chlorinated hydrocarbons in peat

    SciTech Connect

    Rapaport, R.A.

    1985-01-01

    Concentrations (ng/g), accumulation rates (ug/m/sup 2/=yr) and burdens were determined for DDT (1,1,1-trichlorophenyl2-2'bis(p-chlorophenyl)ethane), polychlorinated biphenyls. Toxaphene, hexachlorobenzene (HCB) and a,b,g-hexachlorocyclohexanes (HCHs) in peat cores taken across the mid-latitudes of North America. Because peat bogs are ombrotrophic, thereby receiving all contaminant inputs from the atmosphere and because peat cores were dated, atmospheric input functions were constructed for all of the compounds listed above excepting the HCHs. Compound inventories (burdens) in peat cores of PCBs, HCB, HCHs, Toxaphene, DDT, Pb and Zn were compared, indicating a strong influence from areas proximate to industrial sources and the atmospheric transport from source regions. Untransformed parent DDT (p,p' and o,p'-DDT) in surface peat and in precipitation provides evidence for the long range transport of DDT from neighboring countries where use has increased over the past 10-15 years. Present accumulation rates of DDT in peat are about 10-20% of maximum levels associated with peak use in the US around 1960. The DDT input function that was developed can be used to date peat cores. Transformations of DDT and PCBs were also examined in peat cores. First order transformation rates of DDT (p,p' and o,p') to DDD in anaerobic peat core environments ranged from 0.03 to 0.09 yr/sup -1/ with differences related to temperature. Aerobic transformation of PCB congeners in peat cores and microcosms was rapid for 2,3 and several 4 chlorinated congeners (T/sub 1/2 less than or equal to 0.2 to 3 years) and declined with increasing chlorine number.

  8. Minerals Yearbook, 1989: Peat

    SciTech Connect

    Cantrell, R.L.

    1990-10-01

    U.S. peat demand peaked at 1.5 million tons in 1987, following a 4-year period of record growth. Demand improved by an average of 12% per year during the period, eclipsing previous records. Growth in domestic production was also strong, increasing at an average annual rate of 9%. The following topics relating to peat, are discussed in the report: Domestic Data Coverage; Production; Consumption and Uses; Stocks; Prices; Foreign Trade; World Review; Current Research; Outlook; Background.

  9. Landslides in blanket peat on Cuilcagh Mountain, northwest Ireland

    NASA Astrophysics Data System (ADS)

    Dykes, Alan P.; Gunn, John; Convery (Ne Kirk), Katie J.

    2008-12-01

    The northern and eastern sides of the Cuilcagh Mountain upland, in northwest Ireland, are mantled with over 50 km 2 of blanket bog that has experienced an unusually high spatial and temporal frequency of peat mass movements. In all, 29 peaty-debris slides, nine bog slides, two peat slides and five more peat landslides of uncertain type have been recorded within this study area. More than 27 km 2 of this peatland has been afforded several levels of statutory protection as well as international recognition of its geo-environmental importance. Field and laboratory investigations of the peat at several of the more recent failure sites showed it to be typical of Irish and Pennine (northern England) blanket bogs in most physical and hydrological respects. Field geomorphological evidence and modelling of stability thresholds indicate that the particular susceptibility of the Cuilcagh Mountain blanket bog to failure arises from two local factors: (i) the attainment of threshold maximum peat depths on the East Cuilcagh plateau, and (ii) the unconformable deposition of thin layers of glacial till (in places) and blanket peat over the pre-existing topographic surface formed from the major shale formations that underlie the northern slopes. With two exceptions, there is no conclusive evidence that human activities and management strategies for the area have had any significant influence on the occurrence of the peat landslides. The high frequency of large rainfall events since 1961 that did not trigger landslides suggests that failures are unlikely to become more frequent in response to climate change effects because they are controlled by slowly changing internal thresholds.

  10. The effects of salinization on aerobic and anaerobic decomposition and mineralization in peat meadows: the roles of peat type and land use.

    PubMed

    Brouns, Karlijn; Verhoeven, Jos T A; Hefting, Mariet M

    2014-10-01

    Peat soils comprise a large part of the western and northern Netherlands. Drainage for agriculture has caused increased soil aeration which has stimulated decomposition and, hence, soil subsidence, currently amounting to 1-2 cm/yr. River water is supplied to these peat areas in summer to prevent drying out of the peat soils. Saltwater intrusion and evaporation make this surface water slightly brackish during drought periods. In addition, brackish seepage can surface more easily during such dry periods. We performed an incubation experiment in which the effects of salinization on aerobic decomposition and mineralization of shallow peat samples and anaerobic decomposition and mineralization of deep peat samples were studied. We considered four different types of peat samples: peat sampled in agricultural peat meadows and in nature reserves, originally formed under either eutrophic or oligotrophic conditions. The aerobic decomposition was approximately reduced by 50% after salinization, whereas the anaerobic decomposition rates remained unchanged. Remarkably, the response to salinization did not differ between the peat types and land uses. Ammonium concentrations increased while nitrate concentrations decreased after salinization, probably as a result of reduced nitrification. Especially in the oligotrophic peat, ammonium concentrations increased substantially. Phosphate concentrations increased, possibly caused by changes in desorption and adsorption processes due to higher ion concentrations. DOC concentrations decreased in the brackish samples due to precipitation. Furthermore, the eutrophic peat samples showed increasing sulfate concentrations, both in oxic and anoxic incubations, which was attributed to pyrite oxidation. Independently of salinization, nitrification rates were higher in the agricultural, fertilized, peat soils. In conclusion, while salinization might reduce subsidence rates, it will have adverse effects on water quality. PMID:24837279

  11. Short period of oxygenation releases latch on peat decomposition.

    PubMed

    Brouns, Karlijn; Verhoeven, Jos T A; Hefting, Mariet M

    2014-05-15

    Extreme summer droughts are expected to occur more often in the future in NW Europe due to climate change. These droughts might accelerate the rate of peat oxidation in drained peat areas, with impacts on soil subsidence, GHG emission and water quality. This study aimed at providing more insight in the oxidation of deep peat layers that had not previously been exposed to air, the so-called secondary decomposition. We incubated two types of peat (eutrophic and oligotrophic), sampled from permanently anoxic peat layers from nature reserves and agricultural peat meadows. Peat samples were incubated for thirteen weeks under anoxic conditions, but were exposed to air for one to eight weeks. The production of CO2 and CH4 was quantified as a proxy for decomposition; concentrations of soluble nutrients and phenolic compounds were also measured. The results showed that oxygenation led to a steep increase in the rate of decomposition, indicated by higher carbon loss rates during and after oxygenation compared to non-oxygenated samples. Carbon loss rates increased more for eutrophic peat (agricultural area: 352%, nature reserve: 182%) than for oligotrophic peat (83% and 159% respectively). Most peat samples investigated showed higher post-oxygenation CO2 and/or CH4 production compared to the anoxic pre-oxygenation period. This indicates that oxygenation stimulates decomposition, even after anoxic conditions have returned. Contrary to the enzymic latch theory, no effects of oxygenation on the concentrations of soluble or condensed phenolic compounds were detected. Soluble nutrient concentrations did not change due to oxygenation either. Noteworthy is the occurrence of pyrite mineralization and associated acidification in eutrophic peat. Thus, low summer water levels, for example due to climate change, should be avoided in order to limit exceptionally high decomposition rates and associated problems such as increasing subsidence rates, greenhouse gas emission, sulfate release and acidification. PMID:24583945

  12. First Genome Data from Uncultured Upland Soil Cluster Alpha Methanotrophs Provide Further Evidence for a Close Phylogenetic Relationship to Methylocapsa acidiphila B2 and for High-Affinity Methanotrophy Involving Particulate Methane Monooxygenase

    PubMed Central

    Ricke, Peter; Kube, Michael; Nakagawa, Satoshi; Erkel, Christoph; Reinhardt, Richard; Liesack, Werner

    2005-01-01

    Members of upland soil cluster alpha (USC?) are assumed to be methanotrophic bacteria (MB) adapted to the trace level of atmospheric methane. So far, these MB have eluded all cultivation attempts. While the 16S rRNA phylogeny of USC? members is still not known, phylogenies constructed for the active-site polypeptide (encoded by pmoA) of particulate methane monooxygenase (pMMO) placed USC? next to the alphaproteobacterial Methylocapsa acidiphila B2. To assess whether the pmoA tree reflects the evolutionary identity of USC?, a 42-kb genomic contig of a USC? representative was obtained from acidic forest soil by screening a metagenomic fosmid library of 250,000 clones using pmoA-targeted PCR. For comparison, a 101-kb genomic contig from M. acidiphila was analyzed, including the pmo operon. The following three lines of evidence confirmed a close phylogenetic relationship between USC? and M. acidiphila: (i) tetranucleotide frequency patterns of 5-kb genomic subfragments, (ii) annotation and comparative analysis of the genomic fragments against all completely sequenced genomes available in public domain databases, and (iii) three single gene phylogenies constructed using the deduced amino acid sequences of a putative prephenate dehydratase, a staphylococcal-like nuclease, and a putative zinc metalloprotease. A comparative analysis of the pmo operons of USC? and M. acidiphila corroborated previous reports that both the pmo operon structure and the predicted secondary structure of deduced pMMO are highly conserved among all MB. PMID:16269789

  13. Third technical contractors' conference on peat

    SciTech Connect

    Not Available

    1981-01-01

    The conference dealt with the estimation of US peat reserves, methods for the gasification of peat, including biogasification, techniques for dewatering peat, and the harvesting of peat. Separate abstracts were prepared for the individual papers. (CKK)

  14. Inter-Specific Competition, but Not Different Soil Microbial Communities, Affects N Chemical Forms Uptake by Competing Graminoids of Upland Grasslands

    PubMed Central

    Medina-Roldn, Eduardo; Bardgett, Richard D.

    2012-01-01

    Evidence that plants differ in their ability to take up both organic (ON) and inorganic (IN) forms of nitrogen (N) has increased ecologists interest on resource-based plant competition. However, whether plant uptake of IN and ON responds to differences in soil microbial community composition and/or functioning has not yet been explored, despite soil microbes playing a key role in N cycling. Here, we report results from a competition experiment testing the hypothesis that soil microbial communities differing in metabolic activity as a result of long-term differences to grazing exposure could modify N uptake of Eriophorum vaginatum L. and Nardus stricta L. These graminoids co-occur on nutrient-poor, mountain grasslands where E. vaginatum decreases and N. stricta increases in response to long-term grazing. We inoculated sterilised soil with soil microbial communities from continuously grazed and ungrazed grasslands and planted soils with both E. vaginatum and N. stricta, and then tracked uptake of isotopically labelled NH4+ (IN) and glycine (ON) into plant tissues. The metabolically different microbial communities had no effect on N uptake by either of the graminoids, which might suggest functional equivalence of soil microbes in their impacts on plant N uptake. Consistent with its dominance in soils with greater concentrations of ON relative to IN in the soluble N pool, Eriophorum vaginatum took up more glycine than N. stricta. Nardus stricta reduced the glycine proportion taken up by E. vaginatum, thus increasing niche overlap in N usage between these species. Local abundances of these species in mountain grasslands are principally controlled by grazing and soil moisture, although our results suggest that changes in the relative availability of ON to IN can also play a role. Our results also suggest that coexistence of these species in mountain grasslands is likely based on non-equilibrium mechanisms such as disturbance and/or soil heterogeneity. PMID:23236451

  15. Spatial analysis of soil subsidence in peat meadow areas in Friesland in relation to land and water management, climate change, and adaptation.

    PubMed

    Brouns, Karlijn; Eikelboom, Tessa; Jansen, Peter C; Janssen, Ron; Kwakernaak, Cees; van den Akker, Jan J H; Verhoeven, Jos T A

    2015-02-01

    Dutch peatlands have been subsiding due to peat decomposition, shrinkage and compression, since their reclamation in the 11th century. Currently, subsidence amounts to 1-2 cm/year. Water management in these areas is complex and costly, greenhouse gases are being emitted, and surface water quality is relatively poor. Regional and local authorities and landowners responsible for peatland management have recognized these problems. In addition, the Netherlands Royal Meteorological Institute predicts higher temperatures and drier summers, which both are expected to enhance peat decomposition. Stakeholder workshops have been organized in three case study areas in the province of Friesland to exchange knowledge on subsidence and explore future subsidence rates and the effects of land use and management changes on subsidence rates. Subsidence rates were up to 3 cm/year in deeply drained parcels and increased when we included climate change in the modeling exercises. This means that the relatively thin peat layers in this province (ca 1 m) would shrink or even disappear by the end of the century when current practices continue. Adaptation measures were explored, such as extensive dairy farming and the production of new crops in wetter conditions, but little experience has been gained on best practices. The workshops have resulted in useful exchange of ideas on possible measures and their consequences for land use and water management in the three case study areas. The province and the regional water board will use the results to develop land use and water management policies for the next decades. PMID:25351830

  16. Spatial Analysis of Soil Subsidence in Peat Meadow Areas in Friesland in Relation to Land and Water Management, Climate Change, and Adaptation

    NASA Astrophysics Data System (ADS)

    Brouns, Karlijn; Eikelboom, Tessa; Jansen, Peter C.; Janssen, Ron; Kwakernaak, Cees; van den Akker, Jan J. H.; Verhoeven, Jos T. A.

    2015-02-01

    Dutch peatlands have been subsiding due to peat decomposition, shrinkage and compression, since their reclamation in the 11th century. Currently, subsidence amounts to 1-2 cm/year. Water management in these areas is complex and costly, greenhouse gases are being emitted, and surface water quality is relatively poor. Regional and local authorities and landowners responsible for peatland management have recognized these problems. In addition, the Netherlands Royal Meteorological Institute predicts higher temperatures and drier summers, which both are expected to enhance peat decomposition. Stakeholder workshops have been organized in three case study areas in the province of Friesland to exchange knowledge on subsidence and explore future subsidence rates and the effects of land use and management changes on subsidence rates. Subsidence rates were up to 3 cm/year in deeply drained parcels and increased when we included climate change in the modeling exercises. This means that the relatively thin peat layers in this province (ca 1 m) would shrink or even disappear by the end of the century when current practices continue. Adaptation measures were explored, such as extensive dairy farming and the production of new crops in wetter conditions, but little experience has been gained on best practices. The workshops have resulted in useful exchange of ideas on possible measures and their consequences for land use and water management in the three case study areas. The province and the regional water board will use the results to develop land use and water management policies for the next decades.

  17. Fourth technical contractors' conference on peat

    SciTech Connect

    Not Available

    1981-01-01

    This conference reported the status of the US Department of Energy Peat Program. The papers presented dealt with peat dewatering, international peat programs, environmental and socio-economic factors, peat gasification, peat harvesting, and the state peat surveys for 14 states. Separate abstracts were prepared for the individual papers. (CKK)

  18. Minerals yearbook, 1988: peat

    SciTech Connect

    Cantrell, R.L.

    1988-01-01

    U.S. peat production within the 48 contiguous States declined 6% in 1988. Producers' sales volume and average price received per ton, decreased 3% and 2%, respectively. Ending stocks at the producer level increased 5%. Apparent domestic consumption was 5% below the record 1.5 million tons established during 1986 and 1987. Peat imports increased 15% and reached a record 0.6 million tons, representing 40% of apparent domestic consumption. Canada shipped over 99% of the total. Sphagnum moss sales tonnage increased 142% during the year principally due to development of new high-quality deposits in Minnesota. A significant decline in humus production and sales was experienced.

  19. The effects of ecological restoration on CO2 fluxes from a climatically marginal upland blanket bog

    NASA Astrophysics Data System (ADS)

    Dixon, Simon; Qassim, Suzane; Rowson, James; Worrall, Fred; Evans, Martin

    2013-04-01

    A legacy of gully incision, deposition of industrially-derived aerial pollutants, inappropriate management and wildfire has left large expanses of the topographic Bleaklow Plateau (Peak District National Park, England, UK) bare of vegetation and susceptible to massive erosion of the peat soils. The consequence of such degradation has been to decrease the capacity of the peatland on the plateau to provide important ecosystem services including; loss of net C sink function, discolouration of surface waters, mobilisation to surface waters of stored heavy metals and infilling of upland reservoirs with peat-derived sediment. In response to on-going and worsening degradation a programme of ecological restoration has been undertaken. Restoration methods include: seeding with a lawn grass mix; liming; fertilisation; slope stabilisation; and gully blocking. This talk will present data from a five-year, observational-study of CO2 fluxes from eight sites, with four sites sampling different restoration treatments and four sampling bare and least disturbed areas. The results of the analysis reveal that sites with revegetation alongside slope stabilisation were most productive and were the largest net (daylight hours) sinks of CO2. Unrestored, bare sites, while having relatively low gross fluxes of CO2 were the largest net sources of CO2. Revegetation without slope stabilisation took longer (~18 months) to show an impact on CO2 flux in comparison to the sites with slope stabilisation. Binary logistic regression indicated that a ten centimetre increase in water table depth decreases the odds of observing a net CO2 sink, on a given site, by up to 30%. Sites with slope stabilisation were between 5-8x more likely to be net CO2 sinks than the bare sites. Sites without slope stabilisation were only 2-2.3x more likely to be net CO2 sinks compared to the bare sites. The most important conclusion of this research is that revegetation appears to be effective at increasing the likelihood of net CO2 behaviour on degraded, climatically marginal blanket peat, with revegetation alongside slope stabilisation having the greatest impact.

  20. Diurnal and seasonal patterns of ecosystem CO{sub 2} efflux from upland tundra in the foothills of the Brooks Range, Alaska, U.S.A.

    SciTech Connect

    Oberbauer, S.F.; Gillespie, C.T.; Cheng, Weixin

    1996-08-01

    Carbon dioxide efflux and soil microenvironment were measured in three upland tundra communities in the foothills of the Brooks Range in arctic Alaska to determine the magnitude of CO{sub 2} efflux rates and the relative importance of the belowground factors that influence them. Gas exchange and soil microenvironment measurements were made weekly between 14 June and 31 July 1990. The study communities included lichen-heath, a sparse community vegetated by lichens and dwarf ericaceous shrubs on rocky soils, moist Cassiope dwarf-shrub heath tundra, dominated by Carex and evergreen and deciduous shrubs on relatively deep organic soils, and dry Cassiope dwarf-shrub heath of stone-stripe areas, which was of intermediate character. Rates of CO{sub 2} efflux were similar for the three communities until mid-season when they peaked at rates between 4.9 and 5.9 g m{sup {minus}2} d{sup {minus}1}. Following the mid-season peak, the rates in all three communities declined, particularly in the lichen-heath. Seasonal patterns of CO{sub 2} efflux, soil temperature, and soil moisture suggest changing limitations to CO{sub 2} efflux, soil temperature, and soil moisture suggest changing limitations to CO{sub 2} efflux over the course of the season. Rates of carbon dioxide efflux followed changes in soil temperature early in the season when soil moisture was highest. Mid-season efflux appeared to be limited by soil, moss, and lichen hydration until the end of July, when temperature again limited efflux. Differences between the communities were related to microenvironmental differences and probable differences in carbon quality. The presence of peat-forming mosses is suggested to play an important role in differences in efflux and micro-environment among the communities. 32 refs., 3 figs., 4 tab.

  1. Chemical properties of peat used in balneology

    NASA Astrophysics Data System (ADS)

    Szajdak, L.; Hładoń, T.

    2009-04-01

    The physiological activity of peats is observed in human peat-bath therapy and in the promotion of growth in some plants. Balneological peat as an ecologically clean and natural substance is perceived as being more 'human friendly' than synthetic compounds. Poland has a long tradition of using balneological peat for therapeutic purposes. Balneological peat reveals a physical effect by altering temperature and biochemical effects through biologically active substances. It is mainly used for the treatment of rheumatic diseases that are quite common in Poland. Peat represents natural product. Physico-chemical properties of peat in particular surface-active, sorption and ion exchanges, defining their biological function, depend mainly on the chemical composition and molecular structure of humic substances representing the major constituent of organic soil (peat). The carbon of organic matter of peats is composed of 10 to 20% carbohydrates, primarily of microbial origin; 20% nitrogen-containing constituents, such as amino acids and amino sugars; 10 to 20% aliphatic fatty acids, alkanes, etc.; with the rest of carbon being aromatic. For balneology peat should be highly decomposed (preferably H8), natural and clean. The content of humic acids should exceed 20% of dry weight, ash content will be less than 15 15% of dry weight, sulphur content less than 0.3% of dry weight and the amount of water more than 85%. It will not contain harmful bacteria and heavy metals. Humic substances (HS) of peat are known to be macromolecular polydisperse biphyllic systems including both hydrophobic domains (saturated hydrocarbon chains, aromatic structural units) and hydrophilic functional groups, i. e having amphiphilic character. Amphiphilic properties of FA are responsible for their solubility, viscosity, conformation, surfactant-like character and a variety of physicochemical properties of considerable biologically practical significance. The chemical composition of peats depends significantly on the genesis of peatlands and the depth of sampling. The chemical properties of peat fulvic acids (FA) have some genetic peculiarities due to the specific conditions of the process of humification of peat-forming plants in mires. The process of humification in mires takes place in the top-forming layer under amphibious moisture conditions. Substances of microbial origin are water-soluble and can participate in the formation of peat FA to a little extent. So a main source of structural units for the peat HA and FA is suggested to be organic constituents of peat forming plants of various botanical composition. The content of aromatic units in peat FA was shown to depend on the content of lignin in peat-forming plants and also of the aromatization of polysaccharides mainly due to the transformation of cellulose. FA characterized lower than humic acids molecular weight (1000-30,000). FA's are composed of a series of highly oxidized aromatic rings with a large number of side chains. Building blocks are benzene carboxylic acids and phenolic acids. These are held together by hydrogen bonding van der Waals' forces and ionic bonding. FA contains larger concentrations of nitrogen. This fraction also contains a great deal of polysaccharide materials, as well as low molecular fatty acids and cytoplasmic constituents of microorganisms. These compounds are linear, flexible colloids at low concentrations, and spherical colloids at high solution concentrations and low pH values. A more adequate knowledge of the chemical structure of humic materials will assist us in better understanding the physiological effects and also the function of these macromolecules on the health that these materials are know to exert. This improved knowledge provides us better information on chemical structure of humic substances from peats, which are responsible for pharmacotherapeutic, pharmacokinetic and biopharmaceutical effect. This structure of FA creates proper conditions for uptake of nutrient as well as bioavailability of biologically active substances. The solubilization in water by humic materials of organic substances which are otherwise water-insoluble is a matter of considerable interest to chemist deals with the problem of the function of organic matter. There has been considerable evidence that humic substances can "complex" with several biologically active substances and so modify their physiological activity. It has been noteworthy that FA can "fix" high-molecular weight water-insoluble organic compounds and make them water-soluble. FA may so act as a vehicle for the mobilization, transport and immobilization of such substances in physiological conditions. Analysis of HA and FA carried out by several analytical methods revealed that there were no chemical interaction among biologically active substances but that latter was firmly adsorbed, possible by hydrogen-bonding, on the FA surfaces. Amino acids account for the majority of organic N fraction in humic substances. Most of the amino acids in organic matter occur in bound form in the humino-peptides fraction. These amino acids are commonly bound to the central core of FA. These humino-peptides fraction of FA mediate in respiration and act as hydrogen acceptors, thus affecting oxidation-reaction reactions. Thus, what is needed at this time is more fundamental research in order to solve practical pharmacological, pharmacokinetic and biopharmaceutical problem of great significance for human health.

  2. The effect of fire and permafrost interactions on soil carbon accumulation in an upland black spruce ecosystem of interior Alaska: Implications for post-thaw carbon loss

    USGS Publications Warehouse

    O'Donnell, J. A.; Harden, J.W.; McGuire, A.D.; Kanevskiy, M.Z.; Jorgenson, M.T.; Xu, X.

    2011-01-01

    High-latitude regions store large amounts of organic carbon (OC) in active-layer soils and permafrost, accounting for nearly half of the global belowground OC pool. In the boreal region, recent warming has promoted changes in the fire regime, which may exacerbate rates of permafrost thaw and alter soil OC dynamics in both organic and mineral soil. We examined how interactions between fire and permafrost govern rates of soil OC accumulation in organic horizons, mineral soil of the active layer, and near-surface permafrost in a black spruce ecosystem of interior Alaska. To estimate OC accumulation rates, we used chronosequence, radiocarbon, and modeling approaches. We also developed a simple model to track long-term changes in soil OC stocks over past fire cycles and to evaluate the response of OC stocks to future changes in the fire regime. Our chronosequence and radiocarbon data indicate that OC turnover varies with soil depth, with fastest turnover occurring in shallow organic horizons (~60 years) and slowest turnover in near-surface permafrost (>3000 years). Modeling analysis indicates that OC accumulation in organic horizons was strongly governed by carbon losses via combustion and burial of charred remains in deep organic horizons. OC accumulation in mineral soil was influenced by active layer depth, which determined the proportion of mineral OC in a thawed or frozen state and thus, determined loss rates via decomposition. Our model results suggest that future changes in fire regime will result in substantial reductions in OC stocks, largely from the deep organic horizon. Additional OC losses will result from fire-induced thawing of near-surface permafrost. From these findings, we conclude that the vulnerability of deep OC stocks to future warming is closely linked to the sensitivity of permafrost to wildfire disturbance. ?? 2010 Blackwell Publishing Ltd.

  3. Methylmercury dynamics at the upland-peatland interface: Topographic and hydrogeochemical controls

    NASA Astrophysics Data System (ADS)

    Mitchell, Carl P. J.; Branfireun, Brian A.; Kolka, Randall K.

    2009-02-01

    Peatlands are important environments for the transformation of atmospherically deposited inorganic mercury into the bioaccumulative form, methylmercury (MeHg), which may accumulate in downstream aquatic biota, particularly in fish. In recent research, it was suggested that MeHg production and/or accumulation "hot spots" at the upland-peatland interface were the result of upland fluxes of sulfate and labile dissolved organic carbon (DOC) into the peatland margin. Along the upland-peatland interface, spatial heterogeneity of "hot spots" was thought to be a result of variations in upland hydrologic interaction with the peatland margin. This hypothesis was tested in this study. Pore water MeHg, sulfate, and dissolved organic carbon (DOC) concentrations were compared in peatland plots at the base of both topographically concave and linear upland subcatcments in Minnesota. Subcatchment contributing areas were 3-8 times larger in the peatland plots adjacent to areas of concave upland topography. Peat pore water MeHg concentrations were significantly higher in these plots. Fluxes of water, sulfate, and dissolved organic carbon (DOC) from the upland hillslope into the peatland margin were also generally much larger than those from below areas of concave upland topography. Taken together, these results suggest that watershed geomorphology plays an important role in controlling chemical fluxes into peatland margins and consequently MeHg production and accumulation. It may thus be possible to delineate areas of high MeHg production and/or accumulation in certain watersheds by using high-resolution topographic data. The resulting MeHg "hot spots" may be important for locally foraging biota and for downstream loading, especially in the spring and fall.

  4. Peat resource estimation in South Carolina. Second quarterly report (year 2)

    SciTech Connect

    Cohen, Dr., A. D.; Tisdale, M.; Andrejko, M.; Corvinus, D.; Knight, Richard A.; Olsen, N. K.; Vigerstad, Dr., T. J.

    1981-04-01

    The objectives of this program are to assess the magnitude of the resources and locate areas of highest potential for peat deposits in South Carolina. The energy potential of these peat resources is also being evaluated. This report presents the results of progress made during the last quarter in: assessing data and prioritizing peat areas to be surveyed; procurement of equipment and supplies; and preliminary peat resource assessment. A summary of the results of all new field surveys conducted during the quarter is included. Approximate locations of potential major peat deposits have been identified. Preliminary sampling studies indicate that Pigeon Bay may have the thickest and best quality peat in Berkeley County. Probes indicate peats up to 12 feet thick are located near the Black River in Georgetown County. Samples from areas designated as organic soils by the USDA were analyzed for moisture, organic, and ash content. (DMC)

  5. Temperature and peat type control CO2 and CH4 production in Alaskan permafrost peats.

    PubMed

    Treat, C C; Wollheim, W M; Varner, R K; Grandy, A S; Talbot, J; Frolking, S

    2014-08-01

    Controls on the fate of ~277 Pg of soil organic carbon (C) stored in permafrost peatland soils remain poorly understood despite the potential for a significant positive feedback to climate change. Our objective was to quantify the temperature, moisture, organic matter, and microbial controls on soil organic carbon (SOC) losses following permafrost thaw in peat soils across Alaska. We compared the carbon dioxide (CO2 ) and methane (CH4 ) emissions from peat samples collected at active layer and permafrost depths when incubated aerobically and anaerobically at -5, -0.5, +4, and +20 °C. Temperature had a strong, positive effect on C emissions; global warming potential (GWP) was >3× larger at 20 °C than at 4 °C. Anaerobic conditions significantly reduced CO2 emissions and GWP by 47% at 20 °C but did not have a significant effect at -0.5 °C. Net anaerobic CH4 production over 30 days was 7.1 ± 2.8 μg CH4 -C gC(-1) at 20 °C. Cumulative CO2 emissions were related to organic matter chemistry and best predicted by the relative abundance of polysaccharides and proteins (R(2) = 0.81) in SOC. Carbon emissions (CO2 -C + CH4 -C) from the active layer depth peat ranged from 77% larger to not significantly different than permafrost depths and varied depending on the peat type and peat decomposition stage rather than thermal state. Potential SOC losses with warming depend not only on the magnitude of temperature increase and hydrology but also organic matter quality, permafrost history, and vegetation dynamics, which will ultimately determine net radiative forcing due to permafrost thaw. PMID:24616169

  6. Strength Matters: Resisting Erosion Across Upland Landscapes

    NASA Astrophysics Data System (ADS)

    Heimsath, A. M.

    2012-12-01

    Soil-covered upland landscapes comprise a critical part of the habitable world and our understanding of their evolution as a function of different climatic, tectonic, and geologic regimes is important across a wide range of disciplines. Erosion laws, which help direct our study and drive our models of Earth surface processes are based on little field data. Soil production and transport play essential roles in controlling the spatial variation of soil depth and therefore hillslope hydrological processes, vegetation, and soil biological activity. Field-based confirmation of the hypothesized relationship between soil thickness and soil production is recent, however, and here we quantify the first direct physical explanation of variable soil production across landscapes. We report clear empirical linkages between the mechanical strength of the parent material (erodability), soil production rates determined from the same material, and the routing of water on hillslopes. Specifically, soil production rates determined from in situ produced 10Be and 26Al decrease exponentially with increasing shear strength of parent material across three very different field sites, all underlain by granitic bedrock: The Point Reyes Peninsular and The San Gabriel Mountains in California and the Nunnock River, Australia field site used for extensive previous work. At the same field sites, we use fallout radionuclide profiles to show how the flux of water across the soil-saprolite boundary changes significantly along the hillslope profile. Specifically, we quantify the transition from creep dominated bioturbation on the upper parts of the hillslopes to overland flow dominated surficial erosion towards the axis of the unchannelled swales. Our field-based data, collected across a full range of erosion and soil production rates and topographic settings, help explain more clearly the linkages between biota, weathering, hillslope hydrology, and the evolution of the Earth's surface.

  7. Towards a science of sustainable upland management in developing countries

    NASA Astrophysics Data System (ADS)

    Carpenter, Richard A.; Harper, David E.

    1989-01-01

    Farmers attempting to subsist in tropical uplands often rely upon unsustainable resource use practices that lead to soil erosion, declining crop yields, and a loss of soil productivity capacity. Other uses of tropical uplands, including logging and conversion of forest to rangelands, have similar results. The undesirable effects of these actions are felt on-site, at the watershed level, and even nationally. Ecological cause-effect relationships are poorly understood, and few examples exist of the successful integration of ecological knowledge with upland development. It is hypothesized that recent results of ecological research could be applied to uplands management so that stable sustainable systems of human use may be established. A second hypothesis is that statistically reliable data can be obtained from experiments in upland situations, although natural variations of soils, weather, and vegetation are great. To test these hypotheses, research involving multinational collaboration among American and Southeast Asian scientists has begun. The objective of the work is to provide credible quantitative information to help policy and decision makers and resident farmers to plan and implement improved practices based on ecological principles. Some findings to date include: 1. Ecological principles are difficult to relate to the practical context of upland agroecosystems. Indeed, the null hypothesis is necessary for planning experiments and demonstrations. 2. The “signal-to-noise” ratio in these field experiments is low, and the detection of changes due to human intervention in soil erosion, nutrient movement, and plant productivity is difficult. 3. Obstacles to field research in developing countries include logistic, cultural, political, and institutional factors. It is essential that local land managers participate from the start with scientific researchers in designing experiments. 4. Planned collaboration among academic and government scientists facilitates design of relevant research and the implementation of results. 5. The idea of ecologically based management has been well received by researchers and government officials in Asia. There is little argument with the logic of the approach. 6. Pressures for quick responses to urgent problems in the uplands conflict with the need for careful, long-term, statistically valid scientific research. 7. Ecological principles are vaguely understood and poorly articulated in the scientific literature. The transfer and application of ecological science to the developing world would be enhanced by clearer statements of principles.

  8. The peats of Costa Rica

    SciTech Connect

    Thayer, G.R.

    1991-01-01

    Peat has been identified in Cost Rica, and an economic analysis of energy applications for peat has been done. About 1000 km{sup 2} of Cost Rica has the potential of being covered by peat. The Talamanca Mountains and the northeastern plains contain most of the Costa Rican peat. Specific bogs have been identified by the Medio Queso River in north-central Costa Rica and near El Cairo, Moin, and the Limon airport in northeastern Costa Rica. The Medio Queso bog, which is supplying peat for use as a carrier for nitrogen-fixing bacteria, and the El Cairo bog, which has been identified as a source of horticultural peat for nearby ornamental plant farms, are of special interest. The economics of three energy applications of peat were examined -- as a fuel in large boilers, as a fuel in small boilers, and as an oil substitute in a cement plant. A facility using coal would have the same total costs as one using peat if coal prices were $45 and $30 per metric ton (used for large boilers and a cement plant, respectively). A facility using Bunker C or diesel would have the same total cost as one using peat if oil prices were $0.11, $0.08, and $0.06 per liter (used for large boilers, small boilers, and a cement plant, respectively). In all three cases, the costs for peat were comparable or less than the costs for coal and oil at 1987 prices. 6 refs., 8 figs.

  9. Alfred P. Dachnowski and the scientific study of peats

    USGS Publications Warehouse

    Landa, E.R.; Cohen, K.M.

    2011-01-01

    Botanist Alfred Paul Dachnowski (1875–1949) was a major contributor to efforts at mapping organic soils in the United States during the early 20th century. He began his career at The Ohio State University, and spent most of his professional life at the U.S. Department of Agriculture in Washington, DC. His work spanned a diversity of topics, including bog ecology and the ecosystem services provided by wetlands, the mapping and chemical characterization of peat, and the commercial applications of peat. We present a biography and overview of his work. Dachnowski is best known today for the peat sampler that bears his name. The details of its operation are described here, and its place in modern peat studies is discussed.

  10. Micro-Scale Distribution and Speciation of Arsenic in Peat

    NASA Astrophysics Data System (ADS)

    Langner-Hofmann, Peggy; Mikutta, Christian; Kretzschmar, Ruben

    2013-04-01

    Organic soils and peaty sediments frequently show arsenic (As) enrichments that suggest a direct association of As with natural organic matter (NOM). We have recently studied the speciation of As in a naturally As-enriched minerotrophic peatland (Gola di Lago) located in Southern Switzerland using bulk X-ray absorption spectroscopy (XAS) [1]. These analyses revealed that in deep peat layers, characterized by stable reducing redox conditions, the entire As was coordinated in its trivalent oxidation state to sulfhydryl groups of NOM. In shallow peat layers, however, the suite of As species comprised organically bound As, As sulfides, and As sorbed to Fe(III)-oxyhydroxides. Here we employed micro-X-ray fluorescence (?-XRF) spectrometry combined with ?-XAS to explore the micrometer-scale distribution, speciation, and elemental correlations of As in the Gola di Lago peat. Undisturbed peat material (260-550 mg As/kg) was retrieved from depths

  11. Quantitative trait locus analysis of Verticillium wilt resistance in an introgressed recombinant inbred population of Upland cotton

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Verticillium wilt (VW) of Upland cotton (Gossypium hirsutum L.) is caused by the soil-borne fungal pathogen Verticillium dahlia Kleb. The availability of VW-resistant cultivars is vital for control of this economically important disease, but there is a paucity of Upland cotton breeding lines and cul...

  12. Peat carbon stocks and potential microbial lability of boreal peatlands with varying permafrost histories

    NASA Astrophysics Data System (ADS)

    Olefeldt, D.; Pelletier, N.; Talbot, J.; Blodau, C.; Turetsky, M. R.

    2014-12-01

    Large stores of C in the form of peat are stored in permafrost, particularly in the boreal discontinuous permafrost zone. Ongoing climate change is causing widespread permafrost thaw in boreal peatlands, a trend which is expected to continue this century and thus make large stores of soil C available for microbial processes and mineralization. Permafrost thaw in boreal peatlands is often associated with an ecosystem shift from dry peat plateau to wet bog surfaces, and the net C balance following thaw is determined by the balance between the mineralization of plateau peat and the new accumulation of bog peat on top. In this study we collected soil cores (~3 m deep) from one peat plateaus and four bogs that differed in time since thaw (approximately 10, 50 and 500 years since thaw). In order to assess the potential microbial lability, we incubated 25 soil samples from each core under aerobic conditions at 17.5 deg C. Mineralization rates were 1-2 order of magnitude higher near the surface than at depth, but near surface samples also had high variability among cores. Variability in peat microbial lability near the surface was related to thaw history and to differences in characteristics between plateau and bog peat. Mineralization rates of peat samples from below 1 m depth and down to the interface with mineral soil at 3 m were consistently low and had no difference among cores. Mineralization rates during the first 3 months of incubation for deep plateau peat samples were equivalent to 1% soil C losses per year. Relatively low microbial lability of deep peat in combination with high rates of new peat accumulation during the initial stages of bog development suggests that there is net C accumulation immediately following thaw but that the sink strength weakens or reverses during later stages when new accumulation rates diminish.

  13. The short-term effects of ecological restoration on carbon dioxide fluxes from a Molinia caerulea dominated marginal upland blanket bog.

    NASA Astrophysics Data System (ADS)

    Gatis, Naomi; Luscombe, David; Grand-Clement, Emilie; Hartley, Iain; Anderson, Karen; Brazier, Richard E.

    2014-05-01

    Peat soils in the UK represent a significant long-term carbon store. Despite this the annual imbalance between uptake and release is small and susceptible to change in response to land management, atmospheric deposition and climate change. The shallow marginal peatlands of Exmoor, southwest England, have historically been subject to extensive drainage and are known to be vulnerable to future changes in climate as they lie at the southern edge of the ombrotrophic peatland climatic envelope. However little is known about the processes that drive CO2 fluxes from degraded Molinia caerulea dominated upland mires or the potential effect that restoration through drainage blocking will have. The Mires-on-the-Moors project (www.upstreamthinking.org), funded by South West Water aims to restore the eco-hydrological functionality to over 2000 hectares of drained mire by April 2015. We hypothesised that such mire restoration will return these upland mires to peat forming/carbon sequestering systems. Partitioned below-ground respiration fluxes as well as biotic and abiotic variables, were collected on various dates in 2012 and 2013 along six transects adjacent to three pairs of drainage ditches. One of each pair was restored by blocking with peat dams in spring 2013 whilst the other remained unrestored to act as a control. Monitoring locations were arranged along transects to investigate the spatial variation in gas fluxes with respect to the drainage ditches. By partitioning below-ground fluxes it was possible to monitor root-derived (autotrophic) and more importantly soil-derived (heterotrophic) respiration providing an insight to the effects of ditch blocking on the long term carbon store. Here we present CO2 fluxes for the growing seasons at two critical stages in the restoration process: (a) immediately pre-restoration and (b) immediately post- restoration, and discuss the temporally and spatially variable processes driving below-ground CO2 fluxes. Respiration rates were comparatively low in these shallow humified peats, with daily mean total, heterotrophic and autotrophic respiration reached 1.34, 0.60 and 0.23 ?molCm-2s-1 respectively. As expected soil temperature had a significant control on respiration rates, once this was accounted for water level showed a weak effect on total and heterotrophic respiration. Distinguishing the effects of ecological restoration between a wetter baseline period and a drier post-restoration period had its challenges. However, by expressing the respiration rates in the restored sites as a proportion of that observed in the control sites, the confounding effect of climate variability could be accounted for. This allowed us to determine that heterotrophic respiration decreased at the restored sites comparative to the control sites following restoration, indicating the immediate effect of restoration was to reduce decomposition of the peat store, with implications for carbon sequestration rates.

  14. 7 CFR 1205.305 - Upland cotton.

    Code of Federal Regulations, 2013 CFR

    2013-01-01

    ... 7 Agriculture 10 2013-01-01 2013-01-01 false Upland cotton. 1205.305 Section 1205.305 Agriculture... AND ORDERS; MISCELLANEOUS COMMODITIES), DEPARTMENT OF AGRICULTURE COTTON RESEARCH AND PROMOTION Cotton Research and Promotion Order Definitions § 1205.305 Upland cotton. Upland cotton means all...

  15. 7 CFR 1205.305 - Upland cotton.

    Code of Federal Regulations, 2011 CFR

    2011-01-01

    ... 7 Agriculture 10 2011-01-01 2011-01-01 false Upland cotton. 1205.305 Section 1205.305 Agriculture... AND ORDERS; MISCELLANEOUS COMMODITIES), DEPARTMENT OF AGRICULTURE COTTON RESEARCH AND PROMOTION Cotton Research and Promotion Order Definitions § 1205.305 Upland cotton. Upland cotton means all...

  16. 7 CFR 1205.13 - Upland cotton.

    Code of Federal Regulations, 2010 CFR

    2010-01-01

    ... 7 Agriculture 10 2010-01-01 2010-01-01 false Upland cotton. 1205.13 Section 1205.13 Agriculture... AND ORDERS; MISCELLANEOUS COMMODITIES), DEPARTMENT OF AGRICULTURE COTTON RESEARCH AND PROMOTION Procedures for Conduct of Sign-up Period Definitions § 1205.13 Upland cotton. The term Upland cotton...

  17. 7 CFR 1205.13 - Upland cotton.

    Code of Federal Regulations, 2014 CFR

    2014-01-01

    ... 7 Agriculture 10 2014-01-01 2014-01-01 false Upland cotton. 1205.13 Section 1205.13 Agriculture... AND ORDERS; MISCELLANEOUS COMMODITIES), DEPARTMENT OF AGRICULTURE COTTON RESEARCH AND PROMOTION Procedures for Conduct of Sign-up Period Definitions § 1205.13 Upland cotton. The term Upland cotton...

  18. 7 CFR 1205.305 - Upland cotton.

    Code of Federal Regulations, 2012 CFR

    2012-01-01

    ... 7 Agriculture 10 2012-01-01 2012-01-01 false Upland cotton. 1205.305 Section 1205.305 Agriculture... AND ORDERS; MISCELLANEOUS COMMODITIES), DEPARTMENT OF AGRICULTURE COTTON RESEARCH AND PROMOTION Cotton Research and Promotion Order Definitions § 1205.305 Upland cotton. Upland cotton means all...

  19. 7 CFR 1205.13 - Upland cotton.

    Code of Federal Regulations, 2012 CFR

    2012-01-01

    ... 7 Agriculture 10 2012-01-01 2012-01-01 false Upland cotton. 1205.13 Section 1205.13 Agriculture... AND ORDERS; MISCELLANEOUS COMMODITIES), DEPARTMENT OF AGRICULTURE COTTON RESEARCH AND PROMOTION Procedures for Conduct of Sign-up Period Definitions § 1205.13 Upland cotton. The term Upland cotton...

  20. 7 CFR 1205.13 - Upland cotton.

    Code of Federal Regulations, 2013 CFR

    2013-01-01

    ... 7 Agriculture 10 2013-01-01 2013-01-01 false Upland cotton. 1205.13 Section 1205.13 Agriculture... AND ORDERS; MISCELLANEOUS COMMODITIES), DEPARTMENT OF AGRICULTURE COTTON RESEARCH AND PROMOTION Procedures for Conduct of Sign-up Period Definitions § 1205.13 Upland cotton. The term Upland cotton...

  1. 7 CFR 1205.305 - Upland cotton.

    Code of Federal Regulations, 2014 CFR

    2014-01-01

    ... 7 Agriculture 10 2014-01-01 2014-01-01 false Upland cotton. 1205.305 Section 1205.305 Agriculture... AND ORDERS; MISCELLANEOUS COMMODITIES), DEPARTMENT OF AGRICULTURE COTTON RESEARCH AND PROMOTION Cotton Research and Promotion Order Definitions § 1205.305 Upland cotton. Upland cotton means all...

  2. 7 CFR 1205.13 - Upland cotton.

    Code of Federal Regulations, 2011 CFR

    2011-01-01

    ... 7 Agriculture 10 2011-01-01 2011-01-01 false Upland cotton. 1205.13 Section 1205.13 Agriculture... AND ORDERS; MISCELLANEOUS COMMODITIES), DEPARTMENT OF AGRICULTURE COTTON RESEARCH AND PROMOTION Procedures for Conduct of Sign-up Period Definitions § 1205.13 Upland cotton. The term Upland cotton...

  3. 7 CFR 1205.305 - Upland cotton.

    Code of Federal Regulations, 2010 CFR

    2010-01-01

    ... 7 Agriculture 10 2010-01-01 2010-01-01 false Upland cotton. 1205.305 Section 1205.305 Agriculture... AND ORDERS; MISCELLANEOUS COMMODITIES), DEPARTMENT OF AGRICULTURE COTTON RESEARCH AND PROMOTION Cotton Research and Promotion Order Definitions § 1205.305 Upland cotton. Upland cotton means all...

  4. Soil dissolved organic matter export to coastal temperate rainforest streams

    NASA Astrophysics Data System (ADS)

    Edwards, R. T.; D'Amore, D. V.; Hood, E.; Johnson, A.

    2006-12-01

    The north coastal temperate rainforest is a dynamic area of biogeochemical exchange between terrestrial and aquatic ecosystems. Wetlands and poorly drained soils dominate the landscape, where wetlands alone comprise 30% of the watersheds. The region is experiencing warming with potentially profound impacts on soil processes, forest structure, stream productivity, and the large and valuable salmon fishery. There are few data on stream chemistry, biological productivity, or discharge among soils and streams in the region. To predict the impact of climate change, management practices or land use on streams we need better baseline data on soil-stream interactions in temperate rainforest watersheds. We measured weekly export of dissolved organic matter from 3 dominant soil vegetation communities (peat bogs, forested wetlands and mineral soil uplands) during spring through fall of 2006. Three replicate sites for each soil type were gauged with weirs and fluxes of major forms of carbon, nitrogen and phosphorus measured. Discharge dominated the seasonal flux dynamics but major differences in export and area-specific export emphasized differences in soil-specific transformations on nutrient export potential. Export per unit soil area varied from 0.01 to 25 kg C/ha/day. Peat bogs exported 2-5 times as much per unit area as the other two soils. Forested wetlands were intermediate between bogs and uplands in export per unit area. Mean daily carbon fluxes from gauged subcatchments ranged from 0.01 to 75 kg C/day. Because they are larger than bogs, forested wetlands exported the greatest amount of DOC at our study locations, with uplands exporting intermediate amounts during spring floods. Uplands and bogs exported far less than forested wetlands during normal flow conditions. Total nitrogen fluxes were dominated by organic forms and seasonal trends closely followed the patterns observed for DOC. Although wetlands of either type export more organic matter per unit area, the extent of wetlands varies widely across the landscape; therefore their importance to stream chemistry varies as well. Wetlands comprise from 2 to 95% of total catchment areas in 63 streams within the 6.9 million ha Tongass National Forest in Southeast Alaska, with a mean of 44%. Because of their high areal specific export, wetlands are important organic matter sources within these catchments. Twenty six to thirty six% of the variation in baseflow DOC concentration in watersheds within the Tongass is explained by the amount of combined wetland area within the watershed illustrating the importance of wetland organic matter sources within these stream types. However, the large fluxes from upland mineral soils during spates indicate that uplands also have the capacity to influence stream chemistry during storms. As soils warm, increased mineralization of soil organic matter may increase organic matter export with important impacts on stream chemistry and habitat quality.

  5. Characterisation of VOC, SVOC, and PM emissions from peat burnt in laboratory simulations

    EPA Science Inventory

    Peat, or organic soil, is a vast store of organic carbon, widely distributed from polar temperate to equatorial regions. Drainage for agriculture and drought are drying vast areas of peat, exposing it to increasing fire risk, which may be exacerbated by climate change. This has ...

  6. Global peat erosion risk assessment for the 21st Century

    NASA Astrophysics Data System (ADS)

    Li, Pengfei; Irvine, Brian; Holden, Joseph

    2015-04-01

    Many peatlands across the world are suffering from degradation and erosion exacerbated by human influences. Blanket peat erosion has adverse impacts on terrestrial and aquatic habitats, reservoir capacity and water quality, and also leads to accelerated carbon release. Bioclimatic modelling suggests that some areas, which are currently suitable for active peat growth, may be no longer under a climate supporting the accumulation of peat by the end of the century. Peat erosion in these marginal regions is thus more likely. A recently developed blanket peat erosion model, PESERA-PEAT, was established through significantly modifying the grid version of the Pan-European Soil Erosion Assessment model (PESERA-GRID) to explicitly include the freeze-thaw and desiccation processes, which appear to be the crucial drivers of peat erosion, and typical land management practices in blanket peatlands such as artificial drainage, grazing and managed burning. Freeze-thaw and desiccation are estimated based on climate (i.e. temperature) and soil moisture conditions. Land management practices interact with hydrology, erosion and vegetation growth via their influence on vegetation cover, biomass and soil moisture condition. The model has been demonstrated to be robust for blanket peat erosion modelling with riverine sediment flux data in the UK. In this paper, the PESERA-PEAT model is applied to investigate the impact of environmental change on the blanket peat erosion at a global scale. Climatic scenarios to the end of 21st Century were derived, as part of the QUEST-GSI initiative, from the outputs of seven global climate models: CGCM3 and CCCMA (Canada); CSIRO Mark III (Australia); IPSL (France); ECHAM5 (Germany); CCSM (US National Centre for Atmospheric Research (NCAR)); HadCM3 and HadGEM1 (UK). Land management practice such as artificial drainage is considered to examine if it is possible to buffer the impact of climate change on erosion through managing blanket peatlands in different manners. Interactions between climate change and land management shifts will also be taken into account. The modelling results will be beneficial for the planning of land-use strategies in the blanket peatlands across the world.

  7. Physical and thermochemical properties of uncontaminated and diesel-contaminated peat

    SciTech Connect

    Ghaly, R.A.; Pyke, J.B.; Ghaly, A.E.; Ugursal, V.I.

    1999-06-01

    Peat, plant matter that is partially fossilized, is formed in poorly oxygenated wetlands where the rate at which the plant matter accumulates is greater than the rate at which it decomposes. Peat is a common solid fuel ranking among coal, coke, wood, and sugarcane bagasse. It has also been used to recover oil during the remediation processes of contaminated water and soil. Because of its high moisture content, peat has a high potential as biofuel material for gasification. However, proper understanding of the physical and thermochemical properties of peat is necessary for the design of thermochemical conversion systems. This study provides information on moisture content, bulk density, particle size, heating values, proximate analysis, ultimate analysis, ash composition, and ash fusibility characteristics of uncontaminated and diesel-contaminated peat. The moisture content of uncontaminated peat was 7.10%, whereas that of diesel-contaminated peat ranged from 8.65% to 10.80%. The bulk density for the uncontaminated peat was 151 kg/m{sup 3}, which increased to 391--534 kg/m{sup 3} due to diesel contamination. Most of the particles (60%) were in the form of dust. The results also showed an ash content of 3.23% and the lower heating value of 17.65 MJ/kg (dry weight basis) for the uncontaminated peat. The ash content decreased substantially, whereas the lower heating value increased due to diesel contamination. The ash fusion temperature of the peat was found to be over 1100 C.

  8. Characterization of heterotrophic nitrifying bacteria with respiratory ammonification and denitrification activity--description of Paenibacillus uliginis sp. nov., an inhabitant of fen peat soil and Paenibacillus purispatii sp. nov., isolated from a spacecraft assembly clean room.

    PubMed

    Behrendt, Undine; Schumann, Peter; Stieglmeier, Michaela; Pukall, Rdiger; Augustin, Jrgen; Sprer, Cathrin; Schwendner, Petra; Moissl-Eichinger, Christine; Ulrich, Andreas

    2010-10-01

    In the course of studying the influence of N-fertilization on N(2) and N(2)O flux rates in relation to soil bacterial community composition of a long-term fertilization experiment in fen peat grassland, a strain group was isolated that was related to a strain isolated from a spacecraft assembly clean room during diversity studies of microorganisms, which withstood cleaning and bioburden reduction strategies. Both the fen soil isolates and the clean room strain revealed versatile physiological capacities in N-transformation processes by performing heterotrophic nitrification, respiratory ammonification and denitrification activity. Phylogenetic analysis based on 16S rRNA gene sequences demonstrated that the investigated isolates belonged to the genus Paenibacillus. Sequence similarities lower than 97% in comparison to established species indicated a separate species position. Except for the peptidoglycan type (A4alpha L-Lys-D-Asp), chemotaxonomic features of the isolates matched the genus description, but differences in several physiological characteristics separated them from related species and supported their novel species status. Despite a high 16S rRNA gene sequence similarity between the clean room isolate ES_MS17(T) and the representative fen soil isolate N3/975(T), DNA-DNA hybridization studies revealed genetic differences at the species level. These differences were substantiated by MALDI-TOF MS analysis, ribotyping and several distinct physiological characteristics. On the basis of these results, it was concluded that the fen soil isolates and the clean room isolate ES_MS17(T) represented two novel species for which the names Paenibacillus uliginis sp. nov. (type strain N3/975(T)=DSM 21861(T)=LMG 24790(T)) and Paenibacillus purispatii sp. nov. (type strain ES_MS17(T)=DSM 22991(T)=CIP 110057(T)) are proposed. PMID:20813476

  9. Carbon stocks and soil sequestration rates of riverine mangroves and freshwater wetlands

    NASA Astrophysics Data System (ADS)

    Adame, M. F.; Santini, N. S.; Tovilla, C.; Vzquez-Lule, A.; Castro, L.

    2015-01-01

    Deforestation and degradation of wetlands are important causes of carbon dioxide emissions to the atmosphere. Accurate measurements of carbon (C) stocks and sequestration rates are needed for incorporating wetlands into conservation and restoration programs with the aim for preventing carbon emissions. Here, we assessed whole ecosystem C stocks (trees, soil and downed wood) and soil N stocks of riverine wetlands (mangroves, marshes and peat swamps) within La Encrucijada Biosphere Reserve in the Pacific coast of Mexico. We also estimated soil C sequestration rates of mangroves on the basis of soil accumulation. We hypothesized that riverine wetlands have large C stocks, and that upland mangroves have larger C and soil N stocks compared to lowland mangroves. Riverine wetlands had large C stocks with a mean of 784.5 73.5 Mg C ha-1 for mangroves, 722.2 83.4 Mg C ha-1 for peat swamps, and 336.5 38.3 Mg C ha-1 for marshes. C stocks and soil N stocks were in general larger for upland (833.0 7.2 Mg C ha-1; 26.4 0.5 Mg N ha-1) compared to lowland mangroves (659.5 18.6 Mg C ha-1; 13.8 2.0 Mg N ha-1). Soil C sequestration values were 1.3 0.2 Mg C ha-1 yr-1. The Reserve stores 32.5 Mtons of C or 119.3 Mtons of CO2, with mangroves sequestering (via soil accumulation) 27 762 0.5 Mg C ha-1 every year.

  10. Biochemical processes of oligotrophic peat deposits of Vasyugan Mire

    NASA Astrophysics Data System (ADS)

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

    2009-04-01

    The problem of peat and mire ecosystems functioning and their rational use is the main problem of biosphere study. This problem also refers to forecasting of biosphere changes results which are global and anthropogenic. According to many scientists' research the portion of mires in earth carbon balance is about 15% of world's stock. The aim of this study is to investigate biochemical processes in oligotrophic deposits in North-eastern part of Vasyugan Mire. The investigations were made on the territory of scientific-research ground (56? 03 and 56? 57 NL, 82? 22 and 82? 42 EL). It is situated between two rivers Bakchar and Iksa (in outskirts of the village Polynyanka, Bakchar region, Tomsk oblast). Evolution of investigated mire massif began with the domination of eutrophic phytocenosis - Filicinae, then sedge. Later transfer into oligotrophic phase was accompanied by formation of meter high-moor peat deposit. The age of three-meter peat deposit reaches four thousand years. Biochemical processes of carbon cycle cover the whole peat deposit, but the process activity and its direction in different layers are defined by genesis and duration of peat formation. So, the number of cellulose-fermenting aerobes in researched peat deposits ranges from 16.8 to 75.5 million CFU/g, and anaerobic bacteria from 9.6 to 48.6 million CFU/g. The high number of aerobes is characteristic for high water levels, organizing by raised bog peats. Their number decreases along the profile in 1.7 - 2 times. The number of microflora in peat deposit is defined by the position in the landscape profile (different geneses), by the depth, by hydrothermic conditions of years and individual months. But microflora activity shows along all depth of peat deposit. We found the same in the process of studying of micromycete complex structure. There was revealed either active component micromycete complex - mycelium, or inert one - spores in a meter layer of peat deposit. If mushrooms spores are observed in all deposit layers, mycelium of mushrooms deepens into the peat deposit (to 2 meters) within the limits of aerobic (meter) zone and only in particular months of dry years. The existence of seasonal dynamics of eukaryotic cells, and also capability of yeast and other groups of micromycetes for growth, testifies about vital activity of a number of eukaryotic cells at a depth of 2 meters. Researched peat deposits are biochemically active along the whole profile. But they are different in a microflora number of individual physiological groups either in items of the landscape, or in deposit depth. The largest quantity of aerobic cellulose-fermenting microorganisms is marked during dry years. Anaerobic cellulose-fermenting microorganisms dominate during wet years. The quantity of microbe biomass increases in bottom lifts of peat deposits. This fact testifies about viable condition of microbe complex at depth. The formation process of carbon dioxide in peat deposits of Vasyugan Mire actively occurs during dry years and is defined by hydrothermic conditions of a meter layer of peat deposit. The intensity of CO2 isolation for certain correlates with the temperature in horizon of 0 - 50 sm. and with bog waters level. The study of gas composition for the three years showed that the largest concentration of carbon dioxide in peat soils is marked along the whole profile during a dryer year (0.08 - 2.65 millimole/l), increasing other years' level in about 1.5 0 2 times. Emission of carbon dioxide in peat

  11. The legacy of wetland drainage on the remaining peat in the Sacramento-San Joaquin Delta, California, USA

    USGS Publications Warehouse

    Drexler, Judith Z.; Christian S. de Fontaine; Steven J. Deverel

    2009-01-01

    Throughout the world, many extensive wetlands, such as the Sacramento-San Joaquin Delta of California (hereafter, the Delta), have been drained for agriculture, resulting in land-surface subsidence of peat soils. The purpose of this project was to study the in situ effects of wetland drainage on the remaining peat in the Delta. Peat cores were retrieved from four drained, farmed islands and four relatively undisturbed, marsh islands. Core samples were analyzed for bulk density and percent organic carbon. Macrofossils in the peat were dated using radiocarbon age determination. The peat from the farmed islands is highly distinct from marsh island peat. Bulk density of peat from the farmed islands is generally greater than that of the marsh islands at a given organic carbon content. On the farmed islands, increased bulk density, which is an indication of compaction, decreases with depth within the unoxidized peat zone, whereas, on the marsh islands, bulk density is generally constant with depth except near the surface. Approximately 5580% of the original peat layer on the farmed islands has been lost due to landsurface subsidence. For the center regions of the farmed islands, this translates into an estimated loss of between 2900-5700 metric tons of organic carbon/hectare. Most of the intact peat just below the currently farmed soil layer is over 4000 years old. Peat loss will continue as long as the artificial water table on the farmed islands is held below the land surface.

  12. Understanding fine sediment and phosphorous delivery in upland catchments

    NASA Astrophysics Data System (ADS)

    Perks, M. T.; Reaney, S. M.

    2013-12-01

    The uplands of UK are heavily impacted by land management including; farming and forestry operations, moorland burning, peat extraction, metal mining, artificial drainage and channelisation. It has been demonstrated that such land management activity may modify hillslope processes, resulting in enhanced runoff generation and changing the spatial distribution and magnitude of erosion. Resultantly, few upland river systems of the UK are operating in a natural state, with land management activity often resulting in increased fluxes of suspended sediment (< 2 mm) and associated pollutants (such as phosphorous). Most recent Environment Agency (EA) data reveals that 60% of monitored water bodies within upland areas of the UK are currently at risk of failing the Water Framework Directive (WFD) due to poor ecological status. In order to prevent the continual degradation of many upland catchments, riverine systems and their diverse ecosystems, a range of measures to control diffuse pollution will need to be implemented. Future mitigation options and measures in the UK may be tested and targeted through the EA's catchment pilot scheme; DEFRA's Demonstration Test Catchment (DTC) programmes and through the catchment restoration fund. However, restoring the physical and biological processes of past conditions in inherently sensitive upland environments is extremely challenging requiring the development of a solid evidence base to determine the effectiveness of resource allocation and to enable reliable and transparent decisions to be made about future catchment operations. Such evidence is rarely collected, with post-implementation assessments often neglected. This paper presents research conducted in the Morland sub-catchment of the River Eden within Cumbria; UK. 80% of this headwater catchment is in upland areas and is dominated by improved grassland and rough grazing. The catchment is heavily instrumented with a range of hydro-meteorological equipment. A high-tech monitoring station at the 12.5 km2 outlet provides flow, turbidity, total phosphorous (TP), total reactive phosphorous (TRP), conductivity, temperature and pH measurements at 15-minute intervals. Within this catchment, two additional monitoring stations along adjacent tributaries with catchment areas of 2.3 km2 and 3.8 km2 provide continuous flow and turbidity data with soluble reactive phosphorous and TP collected during storms. Collection and analysis of this data over two full hydrological years has proved effective in; a) producing load estimates; b) producing better assessments of the magnitude and duration of aquatic organisms exposure to detrimental levels of suspended sediment and phosphorous; c) exploring the processes responsible for the delivery and transfer of fine sediment and phosphorous to and from the channel and; d) enhancing our understanding and prediction of the fluvial sediment system. The process understanding achieved using this monitoring framework has facilitated the production of a mitigation plan for the Morland catchment. Following this plan, a range of measures are currently being implemented to reduce the movement of diffuse pollutants across the hillslopes and channels whilst in-stream monitoring continues. The adopted mitigation measures may act as a trial for other upland catchments facing similar pressures.

  13. Impacts of forestry planting on primary production in upland lakes from north-west Ireland.

    PubMed

    Stevenson, Mark A; McGowan, Suzanne; Anderson, N John; Foy, Robert H; Leavitt, Peter R; McElarney, Yvonne R; Engstrom, Daniel R; Pla-Rabés, Sergi

    2016-04-01

    Planted forests are increasing in many upland regions worldwide, but knowledge about their potential effects on algal communities of catchment lakes is relatively unknown. Here, the effects of afforestation were investigated using palaeolimnology at six upland lake sites in the north-west of Ireland subject to different extents of forest plantation cover (4-64% of catchment area). (210) Pb-dated sediment cores were analysed for carotenoid pigments from algae, stable isotopes of bulk carbon (δ(13) C) and nitrogen (δ(15) N), and C/N ratios. In lakes with >50% of their catchment area covered by plantations, there were two- to sixfold increases in pigments from cryptophytes (alloxanthin) and significant but lower increases (39-116%) in those from colonial cyanobacteria (canthaxanthin), but no response from biomarkers of total algal abundance (β-carotene). In contrast, lakes in catchments with <20% afforestation exhibited no consistent response to forestry practices, although all lakes exhibited fluctuations in pigments and geochemical variables due to peat cutting and upland grazing prior to forest plantation. Taken together, patterns suggest that increases in cyanobacteria and cryptophyte abundance reflect a combination of mineral and nutrient enrichment associated with forest fertilization and organic matter influx which may have facilitated growth of mixotrophic taxa. This study demonstrates that planted forests can alter the abundance and community structure of algae in upland humic lakes of Ireland and Northern Ireland, despite long histories of prior catchment disturbance. PMID:26666434

  14. An overview of peat gasification

    NASA Astrophysics Data System (ADS)

    Punwani, D. V.

    Thermal and biological peat gasification processes are reviewed, with research showing that peat is high in both oxygen and hydrogen, and also nitrogen, which can be used to form ammonia as a byproduct. The hydrogen-carbon ratio of peat has been shown to exceed that of subbituminous coal, indicating less of a need to supply more hydrogen in the formation of gaseous fuels. The gasification process involves crushing the peat into particles smaller than 2 mm, which cascade through drying air into a gasifier, where gases from the hydrogasifier induce hydropyrolysis. The char then flows into a reactor with steam and oxygen to make synthesis gas. Minnesota peat has shown the highest hydrocarbon yields in the U.S., and economic comparisons show peak gasification has economic parity with other means of producing SNG. Experiments have also shown the feasibility of wet peat conversion using a peat-water slurry in an anaerobic digestor to produce methane. Building of pilot plants is suggested as necessary to verify existing processes.

  15. Second technical contractors' conference on peat

    SciTech Connect

    Not Available

    1980-01-01

    This conference reported the status of the US Department of Energy Peat Program. The program includes peat resource surveys of eleven states, peat gasification process and equipment studies, dewatering studies, and environmental and socioeconomic factors in the development of peat technology. Separate abstracts were prepared for selected papers. (CKK)

  16. Modelling uncertainty of carbon stocks changes in peats.

    NASA Astrophysics Data System (ADS)

    Poggio, Laura; Gimona, Alessandro; Aalders, Inge; Morrice, Jane; Hough, Rupert

    2015-04-01

    Global warming might change the hydrology of upland blanket peats in Scotland with increased risk of release of the stored carbon. It is therefore important to model the loss of carbon in peat areas with estimation of the damage potential. The presented approach has the potential to provide important information for the assessment of carbon stocks over large areas, but also in case of changes of land use, such as construction of wind farms. The provided spatial uncertainty is important for including the results in further environmental and climate-change models and for decision making in order to provide alternatives and prioritisation. In this study, main peat properties (i.e. depth, water content, bulk density and carbon content) were modelled using a hybrid GAM-geostatistical 3D approach that allows full uncertainty propagation. The approach used involves 1) modelling the trend with full 3D spatial correlation, i.e., exploiting the values of the neighbouring pixels in 3D-space, and 2) 3D kriging as spatial component. The uncertainty of the approach is assessed with iterations in both steps of the process. We studied the difference between local estimates obtained with the present method and local estimates obtained assuming the global average value across the test area for Carbon content and bulk density. To this end, virtual pits with a surface area of 30x30 m were excavated for the whole peat depth at randomly selected locations. Calculated uncertainty was used to estimate credible intervals of C loss. In this case the estimates obtained with the proposed approach are higher that what would be obtained by assuming spatial homogeneity and using just average values across the area. This has implications for environmental decision making and planning as, in this case, it is likely that more carbon would be lost than estimated using traditional approaches.

  17. Climate sensitivity and macronutrient regulation of peat decomposition

    NASA Astrophysics Data System (ADS)

    Marshall, Rachel; Ostle, Nick; McNamara, Niall; Baggs, Elizabeth

    2013-04-01

    Organic soils act as vital global carbon stores maintained in northern latitudes by climate and nutrient limited rates of organic matter decomposition. Peatland decomposition rates are sensitive to climate change, however predicting the magnitude of the microbial respiratory response is complex due to unknown interactions between climate and substrate quality. The nutrient status of peatlands varies widely from mineral rich fens to nutrient poor ombrotrophic bogs, which have the potential to respond differently to climate driven changes in temperature and carbon (C) inputs. In this work we examine the links between peatland macronutrient C, phosphorus (P) and nitrogen (N) stoichiometry, microbial community structure and the microbial response to direct and indirect effects of climate change. Using total soil C:N and C:P ratios to define nutrient gradients in organic soils from Svalbard and Finland we investigated the interaction between the microbial response to temperature and nutrient limitation of decomposition. In organic rich soils from Svalbard we found there was a significant relationship between increasing temperature sensitivity of respiration and decreasing total soil P concentrations. Further investigation of the potential direct link between P limitation of decomposition and increased temperature sensitivity along a minerotrophic-ombroptrophic gradient in Finland was performed using multi-factorial P limitation assays. These showed that despite varying degrees of P limitation across four peatland soils there was no relationship between P limitation and increased temperature sensitivity of soil respiration. Throughout this study we found consistently high temperature sensitivity of decomposition in organic rich soils with Q10 values ranging between 2 to 4.5, indicating potentially higher vulnerability of these C stores to warming than is currently predicted using a globally invariant Q10. Following on from this we examined the interaction between peatland nutrient status and the potential for labile C substrates to stimulate (prime) decomposition of the peat organic matter. Using 13C labelled glucose and hemicellulose compounds we observed significant differences in the amount and rate of microbial substrate use between peats with differing nutrient status. Nutrient addition experiments were used with labelled C substrates to investigate the role of N and P limitation in enhancing or restricting priming effects. This is one of the first studies to use 13C substrates to examine potential priming effects in peat soil and it provides an insight into the importance of priming mechanisms in peat decomposition. This work explicitly links soil microbial responses to temperature and nutrient manipulations with microbial community structure allowing us to observe how microbial communities mediate soil C losses in peat soils. Disentangling the complex interactions between soil microbial community, C and nutrient limitation of decomposition is essential for predicting the vulnerability of different peatland ecosystems to climate driven changes.

  18. Short-column anion-exchange chromatography for soil and peat humic substances profiling by step-wise gradient of high pH aqueous sodium ethylenediaminetetraacetate.

    PubMed

    Hutta, Milan; Rczov, Janka; Gra, Rbert; Pessl, Juraj

    2015-08-21

    Novel anion-exchange liquid chromatographic method with step gradient of aqueous EDTA(4-) based mobile phase elution has been developed to profile available Slovak soil humic substances and alkaline extracts of various soils. The method utilize short glass column (30mm3mm) filled in with hydrolytically stable particles (60?m diameter) Separon HEMA-BIO 1000 having (diethylamino)ethyl functional groups. Step gradient was programmed by mixing mobile phase composed of aqueous solution of sodium EDTA (pH 12.0; 5mmolL(-1)) and mobile phase constituted of aqueous solution of sodium EDTA (pH 12.0, 500mmolL(-1)). The FLD of HSs was set to excitation wavelength 480nm and emission wavelength 530nm (?em). Separation mechanism was studied by use of selected aromatic acids related to humic acids with the aid of UV spectrophotometric detection at 280nm. The proposed method benefits from high ionic strength (I=5molL(-1)) of the end mobile phase buffer and provides high recovery of humic acids (98%). Accurate and reproducible profiling of studied humic substances, alkaline extracts of various types of soils enables straightforward characterization and differentiation of HSs in arable and forest soils. Selected model aromatic acids were used for separation mechanism elucidation. PMID:26143606

  19. Age Determination of the Remaining Peat in the Sacramento-San Joaquin Delta, California, USA

    USGS Publications Warehouse

    Drexler, Judith Z.; de Fontaine, Christian S.; Knifong, Donna L.

    2007-01-01

    Introduction The Sacramento-San Joaquin Delta of California was once a 1,400 square kilometer (km2) tidal marsh, which contained a vast layer of peat ranging up to 15 meters (m) thick (Atwater and Belknap, 1980). Because of its favorable climate and highly fertile peat soils, the majority of the Delta was drained and reclaimed for agriculture during the late 1800s and early 1900s. Drainage of the peat soils changed the conditions in the surface layers of peat from anaerobic (having no free oxygen present) to aerobic (exposed to the atmosphere). This change in conditions greatly increased the decomposition rate of the peat, which consists largely of organic (plant) matter. Thus began the process of land-surface subsidence, which initially was a result of peat shrinkage and compaction, and later largely was a result of oxidation by which organic carbon in the peat essentially vaporized to carbon dioxide (Deverel and others, 1998; Ingebritsen and Ikehara, 1999). Because of subsidence, the land-surface elevation on farmed islands in the Delta has decreased from a few meters to as much as 8 m below local mean sea level (California Department of Water Resources, 1995; Steve Deverel, Hydrofocus, Inc., written commun., 2007). The USGS, in collaboration with the University of California at Davis, and Hydrofocus Inc. of Davis, California, has been studying the formation of the Delta and the impact of wetland reclamation on the peat column as part of a project called Rates and Evolution of Peat Accretion through Time (REPEAT). The purpose of this report is to provide results on the age of the remaining peat soils on four farmed islands in the Delta.

  20. Phosphorus mobilization in rewetted fens: the effect of altered peat properties and implications for their restoration.

    PubMed

    Zak, Dominik; Wagner, Carola; Payer, Brian; Augustin, Jrgen; Gelbrecht, Jrg

    2010-07-01

    Rewetting of drained fens is necessary to stop further soil degradation and to reestablish important ecological functions. However, substantial changes of peat characteristics in the upper soil layers, due to drainage and land use, could counteract their recovery as nutrient-poor systems for an unknown period. We assessed the importance of altered peat properties, such as the degree of peat decomposition and the amount of redox-sensitive phosphorus (P) compounds, for P mobilization in different degraded fens. An experimental design involving 63 intact peat cores from fens with varying drainage and land-use histories was developed to quantify the mobilization of P, as well as that of iron (Fe), ammonium, carbon dioxide, and methane, all indicators of organic-matter decomposition and/or P-releasing processes. We found that net P release rates in peat cores with highly decomposed peat (range: 0.1-52.3 mg P x m(-2) x d(-1)) were significantly correlated to the amount of P bound to redox-sensitive compounds and the molar Fe:P as well as Al:P ratios of peat. We conclude that the following general rules apply for P mobilization in rewetted fens: (1) elevated levels of P release rates and P concentrations in pore water up to three orders of magnitude larger than under natural reference conditions can only be expected for rewetted fens whose surface soil layers consist of highly decomposed peat; (2) peat characteristics, such as the amount of P bound to redox-sensitive Fe(III) compounds (positive correlation) and molar ratios of Fe:P or Al:P (negative correlations), explain the high range of P release rates; and (3) a critical P export to adjacent lakes or rivers can only be expected if molar Fe:P ratios of highly decomposed peat are less than 10. PMID:20666253

  1. Carbon dioxide emissions through oxidative peat decomposition on a burnt tropical peatland.

    PubMed

    Hirano, Takashi; Kusin, Kitso; Limin, Suwido; Osaki, Mitsuru

    2014-02-01

    In Southeast Asia, a huge amount of peat has accumulated under swamp forests over millennia. Fires have been widely used for land clearing after timber extraction, thus land conversion and land management with logging and drainage are strongly associated with fire activity. During recent El Nio years, tropical peatlands have been severely fire-affected and peatland fires enlarged. To investigate the impact of peat fires on the regional and global carbon balances, it is crucial to assess not only direct carbon emissions through peat combustion but also oxidative peat decomposition after fires. However, there is little information on the carbon dynamics of tropical peat damaged by fires. Therefore, we continuously measured soil CO2 efflux [peat respiration (RP)] through oxidative peat decomposition using six automated chambers on a burnt peat area, from which about 0.7m of the upper peat had been lost during two fires, in Central Kalimantan, Indonesia. The RP showed a clear seasonal variation with higher values in the dry season. The RP increased logarithmically as groundwater level (GWL) lowered. Temperature sensitivity or Q10 of RP decreased as GWL lowered, mainly because the vertical distribution of RP would shift downward with the expansion of an unsaturated soil zone. Although soil temperature at the burnt open area was higher than that in a near peat swamp forest, model simulation suggests that the effect of temperature rise on RP is small. Annual gap-filled RP was 38282 (the mean1 SD of six chambers) and 36274gCm(-2) yr(-1) during 2004-2005 and during 2005-2006years, respectively. Simulated RP showed a significant negative relationship with GWL on an annual basis, which suggests that every GWL lowering by 0.1m causes additional RP of 89gCm(-2) yr(-1) . The RP accounted for 21-24% of ecosystem respiration on an annual basis. PMID:23775585

  2. Dewatering Peat With Activated Carbon

    NASA Technical Reports Server (NTRS)

    Rohatgi, N. K.

    1984-01-01

    Proposed process produces enough gas and carbon to sustain itself. In proposed process peat slurry is dewatered to approximately 40 percent moisture content by mixing slurry with activated carbon and filtering with solid/liquid separation techniques.

  3. Peat as an energy alternative

    SciTech Connect

    Punwani, D.V.

    1980-07-01

    The importance of developing alternative energy sources to augment supplies of fossil fuels is growing all over the world. Coal, oil shale, tar sands, biomass, solar, geothermal, nuclear, and hydroelectric power have received considerable attention as alternative energy sources. One large energy resource, however, has received little attention until recently. That resource is peat. Although peat is used as an energy source in some countries such as Russia, Ireland, and Finland, it is virtually unexploited in many countries including the United States. This paper provides an understanding of peat: its varieties, abundance, and distribution; its value as an energy alternative; its current and future role as an energy alternative; and the environmental and socioeconomic impacts of large-scale peat utilization.

  4. Control of Submarine Groundwater Flow and Chemistry by Onshore and Offshore Buried Peat Along a Developed Long Island Shoreline

    NASA Astrophysics Data System (ADS)

    Bratton, J. F.; Kroeger, K. D.; Crusius, J.; Schubert, C.; Paulsen, R.; Green, A. C.; Wanlass, J.; Baldwin, S.; Abbene, I. J.; Young, C.

    2010-12-01

    Submarine groundwater discharge (SGD) along the north shore of Long Island’s Great South Bay estuary was investigated to characterize and quantify nutrient delivery to the bay from groundwater. Recent field activities included onshore and offshore piezometer and well sampling, sediment coring, stationary resistivity profiling, and surveys of in situ porewater conductivity. Groundwater and surface water were sampled for analysis of nutrients, water quality parameters (conductivity, temperature, pH, ORP, dissolved oxygen), and age tracers. Results from detailed study at Patchogue Bay sites showed shallow plumes of low-salinity groundwater (salinity <3.5) located within 0.5 m of the estuary floor that decreased in thickness along one transect from approximately 4.5 m near shore to <1 m at 90 m offshore. Sediment cores collected near shore recovered buried submarine peat layers up to 49 cm thick that isolated low-salinity (salinity = 2-4) porewater below from brackish porewater above. In situ measurements of porewater conductivity and temperature in the upper 0.7 m of the sediment at one site verified the presence and extent of the peat layer there, as well as the isolation of terrestrially-derived groundwater beneath the layer extending offshore about 100 meters. Stationary electrical resistivity measurements also revealed the presence of high-resistivity (low-salinity) groundwater beneath the peat layer and more conductive porewater above the peat layer. Peat was found adjacent to existing or filled tidal creeks but was absent in cores collected offshore of the ends of peninsulas between tidal creeks. Much of the natural shoreline of the bay was developed in the 1950s and 1960s after construction of bulkheads and filling of tidal marshes with dredged or dumped fill material. Recharge of groundwater through buried peats and organic-rich soils in developed filled areas results in adjacent submarine groundwater plumes that are anoxic and ammonium-rich (average = 255 micromoles of ammonium per liter in offshore samples; max = 593 [n = 41]). Tritium data collected previously in this area indicate that groundwater recharged within the last few decades discharges relatively close to shore, but that the age of groundwater increases with depth and distance offshore. Recent samples from offshore profile wells contained detectable concentrations of MTBE and volatile organic compounds in the deeper low-salinity intervals, consistent with recharge of this groundwater further inland than younger and shallower submarine groundwater that did not contain detectable concentrations of these compounds. Land use patterns in the upland area of the watershed support this trend. Better understanding of the distributions of age and chemical composition along developed shorelines such as this could lead to improved models and mitigation strategies for estuarine nutrient over-enrichment.

  5. Transport and fate of trifluoroacetate in upland forest and wetland?ecosystems

    PubMed Central

    Likens, G. E.; Tartowski, S. L.; Berger, T. W.; Richey, D. G.; Driscoll, C. T.; Frank, H. G.; Klein, A.

    1997-01-01

    Although trifluoroacetate (TFA), a breakdown product of chlorofluorocarbon replacements, is being dispersed widely within the biosphere, its ecological fate is largely unknown. TFA was added experimentally to an upland, northern hardwood forest and to a small forest wetland ecosystem within the Hubbard Brook Experimental Forest in New Hampshire. Inputs of TFA were not transported conservatively through these ecosystems; instead, significant amounts of TFA were retained within the vegetation and soil compartments. More TFA was retained by the wetland ecosystem than by the upland forest ecosystem. Using simulation modeling, TFA concentrations were predicted for soil and drainage water until the year 2040. PMID:9114018

  6. A new model for studying the impacts of land cover change on flood hydrographs in upland peatland catchments

    NASA Astrophysics Data System (ADS)

    Gao, Jihui; Kirkby, Mike; Holden, Joseph

    2014-05-01

    There is global concern about headwater management and associated impacts on river flow. In many wet temperate zones peatlands can be found in headwater catchments. In the UK there is major concern about how environmental change, driven by human interventions, has altered the surface cover of headwater blanket peatlands. However, the impact of such cover changes on river flow is poorly understood. In particular, there is poor understanding of the how different spatial configurations of vegetation impact on the management of river flow peaks in upland catchments. This paper employs a numerical modelling approach to explore such impacts. TOPMODEL, due to its process representation which is very suitable for blanket peat catchments, was utilized as a prototype acting as the basis for a new distributed catchment hydrological model. The new model is totally distributed with a computational unit of a grid cell. The core equations representing subsurface flow in the original TOPMODEL were inherited by the distributed version of TOPMODEL and downscaled from the catchment level to the cell level for the transformation to the distributed model. The downscaled equations constitute the main part of the subsurface flow module and the runoff produced by each cell is obtained by partitioning rainfall between evapotranspiration, subsurface flow and saturation-excess overland flow in the extended model. A new overland flow module with a set of stochastic algorithms for overland flow transport was created to simulate overland flow movement, in which the overland flow produced in each cell is treated as many parcels (e.g. 100 parcels) of water. The flow velocity is calculated by the local slope, the overland flow depth, and the land surface roughness (associated with land cover types) based on empirical data. For each parcel the direction and distance of its movement in a single time step is obtained as a stochastic process, based on the partition of flow between downslope directions and the average flow velocity, interpreted as a probability of stopping in each cell traversed. This module also include a re-infiltration mechanism in which the overland flow yielded in upslope cells can infiltrate into the unsaturated soil in downslope cells to contribute to subsurface flow produced in these cells. This rarely considered mechanism in hydrological models shows one important way in which the real process of overland flow generation on hillslopes may be influenced by land cover. This significant new advance may have wide applicability, and there is only one new key parameter (overland flow velocity parameter) which replaces the constant overland flow velocity in the original TOPMODEL, limiting the possibilities of over-parameterization. The new model was tested in three upland peat catchments in different parts of the UK: Trout Beck in the North Pennines, the Wye in mid-Wales and the East Dart in southwest England. The model was found to work well in all three cases, and could be employed in future land cover scenario studies concerning impacts of land cover change on river flow in upland peatlands.

  7. Landscape heterogeneity, soil climate, and carbon exchange in a boreal black spruce forest.

    PubMed

    Dunn, Allison L; Wofsy, Steven C; v H Bright, Alfram

    2009-03-01

    We measured soil climate and the turbulent fluxes of CO2, H2O, heat, and momentum on short towers (2 m) in a 160-yr-old boreal black spruce forest in Manitoba, Canada. Two distinct land cover types were studied: a Sphagnum-dominated wetland, and a feathermoss (Pleurozium and Hylocomium)-dominated upland, both lying within the footprint of a 30-m tower, which has measured whole-forest carbon exchange since 1994. Peak summertime uptake of CO2, was higher in the wetland than for the forest as a whole due to the influence of deciduous shrubs. Soil respiration rates in the wetland were approximately three times larger than in upland soils, and 30% greater than the mean of the whole forest, reflecting decomposition of soil organic matter. Soil respiration rates in the wetland were regulated by soil temperature, which was in turn influenced by water table depth through effects on soil heat capacity and conductivity. Warmer soil temperatures and deeper water tables favored increased heterotrophic respiration. Wetland drainage was limited by frost during the first half of the growing season, leading to high, perched water tables, cool soil temperatures, and much lower respiration rates than observed later in the growing season. Whole-forest evapotranspiration increased as water tables dropped, suggesting that photosynthesis in this forest was rarely subject to water stress. Our data indicate positive feedback between soil temperature, seasonal thawing, heterotrophic respiration, and evapotranspiration. As a result, climate warming could cause covariant changes in soil temperature and water table depths that may stimulate photosynthesis and strongly promote efflux of CO2 from peat soils in boreal wetlands. PMID:19323205

  8. Revegetation processes and environmental conditions in abandoned peat production fields in Estonia

    NASA Astrophysics Data System (ADS)

    Orru, M.; Orru, H.

    2009-04-01

    As a result of peat extraction, peat production has been finished in Estonia at different times in 154 peat production areas and 9,500 ha (~1% of peatlands) are abandoned, although the peat reserves are not exhausted yet; besides, several areas are not properly recultivated. In addition 12,000 ha of fens (oligotrophic peat layers) are drained and used as grasslands. If the abandoned and non-recultivated peat production areas are not vegetated, their CO2 emission is considerable and peat mineralises in such areas. The aim of the study was to find out specific ecological and geological factors, which affect recovering of peatlands and influence the recultivation. During the revision the amount and quality of the remained reserves, as well as the state of water regime, drainage network and revegetation was assessed in all 154 abandoned peat production areas. The study showed that the state of them is very variable. Some of them are covered with forest, prevailingly with birches at former drainage ditches, later supplemented by pine trees. In the others predominate grasses among plants, and various species of moss (Cladonia rei, Bryum caespiticum, Sphagnum ripariuma, Sphagnum squarrosum) occur as well. Besides, some abandoned areas are completely overgrown with cotton grass. Open abandoned peat areas, which are not covered by vegetation, are much rarer. We found out, that water regime among the factors plays most important role. Moreover abandoned peat production fields, where the environmental conditions have changed - are appropriate for growth of several moss species, which cannot inhabit the areas already occupied by other species. The most interesting discovers were: second growing site of Polia elongata in West-Estonia and Ephemerum serratum, last found in Estonia in the middle of the 19th century, was identified in central Estonia. Also Campylopus introflexus, what was unknown in Estonia. However, the changes in environmental conditions influence the peat layers structure and technical characteristics of organic soils that affect the vegetation of peatlands.

  9. Differential peat deformation, compressibility, and water storage between peatland microforms: Implications for ecosystem function and development

    NASA Astrophysics Data System (ADS)

    Waddington, J. M.; Kellner, E.; Strack, M.; Price, J. S.

    2010-07-01

    Because peat is elastic, the daily to seasonal swelling and shrinking of the peat surface not only affects water storage but also alters peatland hydraulics and the biogeochemical and thermal properties of peat. Due to different botanical origins and degrees of decomposition, we hypothesized that different peatland microforms (ridges and lawns) display a large variation in peat deformation and compressibility. Here we examined the spatial variation of peat surface movement, peat strength, and volumetric water content at a low lawn (LL), upper lawn (UL), and ridge (R) along a 5 m transect in a peatland in Quebec, Canada. The average seasonal amplitude in peat surface level was 9, 6, and 2 cm at the LL, UL, and R sites, respectively. The surface layers in each of these sites were fairly rigid with the largest changes in peat thickness occurring between 20 and 60 cm depth in the peat profile. Compressibility varied among microforms but was not correlated to other properties within the layer in individual soil layers. However, when average profile compressibility was considered, it was significantly correlated to peat depth, von Post humification, distance to hollow, and peat strength. The total water storage by dilation below the water table was about the same as the water deficit (precipitation minus evapotranspiration) for LL, while the storage deficit for UL and especially R was lower. Including changes in entrapped gas content over the season reduced estimates of changes in water storage at all sites. Because microform type and position were significant predictors of hydrophysical properties, we argue that this suggests that peatland microtopography is self-reinforcing through ecohydrological feedbacks. Including the variability in these properties in peatland ecohydrological models will be key for predicting the response of peatland ecosystems to disturbance.

  10. 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.

  11. Evapotranspiration of tropical peat swamp forests.

    PubMed

    Hirano, Takashi; Kusin, Kitso; Limin, Suwido; Osaki, Mitsuru

    2015-05-01

    In Southeast Asia, peatland is widely distributed and has accumulated a massive amount of soil carbon, coexisting with peat swamp forest (PSF). The peatland, however, has been rapidly degraded by deforestation, fires, and drainage for the last two decades. Such disturbances change hydrological conditions, typically groundwater level (GWL), and accelerate oxidative peat decomposition. Evapotranspiration (ET) is a major determinant of GWL, whereas information on the ET of PSF is limited. Therefore, we measured ET using the eddy covariance technique for 4-6 years between 2002 and 2009, including El Nio and La Nia events, at three sites in Central Kalimantan, Indonesia. The sites were different in disturbance degree: a PSF with little drainage (UF), a heavily drained PSF (DF), and a drained burnt ex-PSF (DB); GWL was significantly lowered at DF, especially in the dry season. The ET showed a clear seasonal variation with a peak in the mid-dry season and a large decrease in the late dry season, mainly following seasonal variation in net radiation (Rn ). The Rn drastically decreased with dense smoke from peat fires in the late dry season. Annual ET forced to close energy balance for 4 years was 1636 53, 1553 117, and 1374 75 mm yr(-1) (mean 1 standard deviation), respectively, at UF, DF, and DB. The undrained PSF (UF) had high and rather stable annual ET, independently of El Nio and La Nia events, in comparison with other tropical rainforests. The minimum monthly-mean GWL explained 80% of interannual variation in ET for the forest sites (UF and DF); the positive relationship between ET and GWL indicates that drainage by a canal decreased ET at DF through lowering GWL. In addition, ET was decreased by 16% at DB in comparison with UF chiefly because of vegetation loss through fires. PMID:24912043

  12. Variability of humic acid properties depending on their precursor material: a study of peat profiles

    NASA Astrophysics Data System (ADS)

    Klavins, Maris; Purmalis, Oskars

    2015-04-01

    Analysis of variation of peat composition, presence of trace elements in the peat and HSs within peat profiles can give information on the character of transformation of organic matter, important for C biogeochemical cycling, but also about impacts of climate change and human activities. In peat the transformation and decay process of living organic matter (humification) is retarded by the acidic and anaerobic environment, but at the same time the peat can provide information on environmental and paleo-environmental conditions of the past. The aim of the present study is to analyze the elemental and functional composition, spectral characteristics of humic acids isolated from a well characterized raised bog peat profiles to evaluate the impact of the character of humification processes on the peat HA properties. A comparative and complex characterization of humic acids (HAs) isolated from peat profiles of different origin in Latvia was carried out. Elemental and functional analysis of the isolated HAs was done, their acidity and molecular weights estimated. Spectral characterization included UV-Vis, IR, and electron spin resonance and fluorescence spectra. Structural characterization of HAs was by both 1H and 13C nuclear magnetic resonance spectra. Comparison of position of studied humic acids in the Van Krevelen graph was done, thus locating them in the biogeochemical transformation processes of organic matter. Properties of HAs isolated from the Latvian peat were compared with HA from other sources (soil, water, coal and synthetic humic substances). Major properties of peat HAs depended on their origin, indicating the importance of humification processes. HAs isolated from peat of more recent origin were more similar to soil HAs, but from older sources there was a greater degree of humification. Changes of surface tension of solutions of humic acids stress the differences in aggregation character - ability to form supramacromolecular complexes of humic substances and impact of environmental conditions on the surfactant properties of humic matter. Amongst the main objectives of the study was the identification of the dependence of the humic acid properties on the composition of original living matter in the peat, especially considering high variability of peat composition in the studied bogs. Despite some correlation between peat botanical composition and properties exist, in general the similarities are much more expressed, thus indicating the significance of microbial decay processes on the properties of humic material. Acknowledgement: Support from a project ResProd

  13. Correlation analysis as a tool to investigate the bioaccessibility of nickel, vanadium and zinc in Northern Ireland soils.

    PubMed

    Palmer, Sherry; Ofterdinger, Ulrich; McKinley, Jennifer M; Cox, Siobhan; Barsby, Amy

    2013-10-01

    Correlation analyses were conducted on nickel (Ni), vanadium (V) and zinc (Zn) oral bioaccessible fractions (BAFs) and selected geochemistry parameters to identify specific controls exerted over trace element bioaccessibility. BAFs were determined by previous research using the unified BARGE method. Total trace element concentrations and soil geochemical parameters were analysed as part of the Geological Survey of Northern Ireland Tellus Project. Correlation analysis included Ni, V and Zn BAFs against their total concentrations, pH, estimated soil organic carbon (SOC) and a further eight element oxides. BAF data were divided into three separate generic bedrock classifications of basalt, lithic arenite and mudstone prior to analysis, resulting in an increase in average correlation coefficients between BAFs and geochemical parameters. Sulphur trioxide and SOC, spatially correlated with upland peat soils, exhibited significant positive correlations with all BAFs in gastric and gastro-intestinal digestion phases, with such effects being strongest in the lithic arenite bedrock group. Significant negative relationships with bioaccessible Ni, V and Zn and their associated total concentrations were observed for the basalt group. Major element oxides were associated with reduced oral trace element bioaccessibility, with Al2O3 resulting in the highest number of significant negative correlations followed by Fe2O3. spatial mapping showed that metal oxides were present at reduced levels in peat soils. The findings illustrate how specific geology and soil geochemistry exert controls over trace element bioaccessibility, with soil chemical factors having a stronger influence on BAF results than relative geogenic abundance. In general, higher Ni, V and Zn bioaccessibility is expected in peat soil types. PMID:23793447

  14. Artificial radioactivity in fuel peat and peat ash in Finland after the Chernobyl accident

    SciTech Connect

    Mustonen, R.A.; Reponen, A.R.; Jantunen, M.J.

    1989-04-01

    The accident at the Chernobyl nuclear power plant in April 1986 caused very uneven deposition of radionuclides in Finland. The deposited radionuclides were found in relatively high concentrations in fuel peat and especially in peat ash because a thin surface layer of peat-production bogs was extracted as fuel peat soon after the fallout occurred. Concentrations of artificial radionuclides in fuel peat and peat ash were measured at six peat-fired power plants in Finland throughout the heating season 1986-87. Concentrations of /sup 137/Cs in composite peat samples varied between 30 and 3600 Bq kg-1 dry weight and in ash samples between 600 and 68,000 Bq kg-1. High concentrations in peat ash caused some restrictions to the utilization of peat ash for various purposes.

  15. Runoff water quality from a sierran upland forest, transition ecotone, and riparian wet meadow

    Technology Transfer Automated Retrieval System (TEKTRAN)

    High concentrations of inorganic N, P, and S have been reported in overland and litter interflow within forested uplands of the Tahoe basin and surrounding watersheds. In this study we compared runoff nutrient concentration and load as well as soil nutrient fluxes at three watershed locations; an up...

  16. Catchment and in-stream influences on iron-deposit chemistry, algal-bacterial biomass and invertebrate richness in upland streams, Northern Ireland.

    NASA Astrophysics Data System (ADS)

    Macintosh, Katrina Ann; Griffiths, David

    2013-04-01

    The density and composition of upland stream bed iron-deposits is affected by physical, chemical and biological processes. The basic chemical processes producing ochre deposits are well known. Mobilisation of iron and manganese is influenced by bedrock weathering, the presence of acidic and/or reducing conditions and the concentration of dissolved organic carbon. Ferromanganese-depositing bacteria are significant biogenic agents and can cause/enhance the deposition of metals in streams as (hydr)oxides. Metal concentrations from stream waters in two geological blocks in Northern Ireland were compared to determine the contributions of catchment characteristics and in-stream conditions. One block is composed of metamorphosed schist and unconsolidated glacial drift, with peat or peaty podzol (mainly humic) soils, while the other block consists of tertiary basalt with brown earth and gley soils. Water samples were collected from 52 stream sites and analysed for iron, manganese and aluminium as well as a range of other chemical determinands known to affect metal solubility. Stone deposit material was analysed for metal concentrations, organic matter content and epilithic algae, chlorophyll a concentration. Invertebrates were collected by area-standardised kick samples and animals identified to family and numbers counted. Higher conductivities and concentrations of bicarbonate, alkalinity, calcium and magnesium occurred on basalt than on schist. Despite higher iron and manganese oxide concentrations in basalt-derived non-humic soils, stream water concentrations were much lower and stone deposit concentrations only one third of those occurring on schist overlain by humic soils. Peat-generated acidity and the limited acid neutralising capacity of base-poor metamorphosed schist has resulted in elevated concentrations of metals and ochre deposit in surface waters. Algal biomass was determined by catchment level factors whereas in-stream conditions affected bacterial biomass. Strong, non-linear, relations occurred between estimated bacterial biomass and deposit metal concentrations, with iron and manganese becoming relatively more important and algal biomass declining above a threshold deposit/bacterial density. Invertebrate community structure was altered above a deposit density of 10 mg cm-2, when invertebrate richness and diversity declined. These changes are driven by an increase in estimated bacterial biomass.

  17. 46 CFR 148.290 - Peat moss.

    Code of Federal Regulations, 2012 CFR

    2012-10-01

    ... 46 Shipping 5 2012-10-01 2012-10-01 false Peat moss. 148.290 Section 148.290 Shipping COAST GUARD... SPECIAL HANDLING Special Requirements for Certain Materials § 148.290 Peat moss. (a) Before shipment, peat moss must be stockpiled under cover to allow drainage and reduce its moisture content. (b) The...

  18. 46 CFR 148.290 - Peat moss.

    Code of Federal Regulations, 2011 CFR

    2011-10-01

    ... 46 Shipping 5 2011-10-01 2011-10-01 false Peat moss. 148.290 Section 148.290 Shipping COAST GUARD... SPECIAL HANDLING Special Requirements for Certain Materials § 148.290 Peat moss. (a) Before shipment, peat moss must be stockpiled under cover to allow drainage and reduce its moisture content. (b) The...

  19. 46 CFR 148.290 - Peat moss.

    Code of Federal Regulations, 2013 CFR

    2013-10-01

    ... 46 Shipping 5 2013-10-01 2013-10-01 false Peat moss. 148.290 Section 148.290 Shipping COAST GUARD... SPECIAL HANDLING Special Requirements for Certain Materials § 148.290 Peat moss. (a) Before shipment, peat moss must be stockpiled under cover to allow drainage and reduce its moisture content. (b) The...

  20. 46 CFR 148.290 - Peat moss.

    Code of Federal Regulations, 2014 CFR

    2014-10-01

    ... 46 Shipping 5 2014-10-01 2014-10-01 false Peat moss. 148.290 Section 148.290 Shipping COAST GUARD... SPECIAL HANDLING Special Requirements for Certain Materials § 148.290 Peat moss. (a) Before shipment, peat moss must be stockpiled under cover to allow drainage and reduce its moisture content. (b) The...

  1. 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

  2. Strong Wavelength Dependence of Aerosol Light Absorption from Peat Combustion

    NASA Astrophysics Data System (ADS)

    Gyawali, M. S.; Chakrabarty, R. K.; Yatavelli, R. L. N.; Chen, L. W. A. A.; Knue, J.; Samburova, V.; Watts, A.; Moosmller, H.; Arnott, W. P.; Wang, X.; Zielinska, B.; Chow, J. C.; Watson, J. G.; Tsibart, A.

    2014-12-01

    Globally, organic soils and peats may store as much as 600 Gt of terrestrial carbon, representing 20 - 30% of the planet's terrestrial organic carbon mass. This is approximately the same carbon mass as that contained in Earth's atmosphere, despite peatlands occupying only 3% of its surface. Effects of fires in these ecosystems are of global concern due to their potential for enormous carbon release into the atmosphere. The implications for contributions of peat fires to the global carbon cycle and radiative forcing scenarios are significant. Combustion of peat mostly takes place in the low temperature, smoldering phase of a fire. It consumes carbon that may have accumulated over a period of hundreds to thousands of years. In comparison, combustion of aboveground biomass fuels releases carbon that has accumulated much more recently, generally over a period of years or decades. Here, we report our findings on characterization of emissions from laboratory combustion of peat soils from three locations representing the biomes in which these soils occur. Peat samples from Alaska and Florida (USA) and Siberia (Russia) were burned at two different fuel moisture levels. Burns were conducted in an 8-m3 volume combustion chamber located at the Desert Research Institute, Reno, NV, USA. We report significant brown carbon production from combustion of all three peat soils. We used a multispectral (405, 532, 781 nm) photoacoustic instrument equipped with integrating nephelometer to measure the wavelength-dependent aerosol light absorption and scattering. Absorption ngstrm exponents (between 405 and 532 nm) as high as ten were observed, revealing strongly enhanced aerosol light absorption in the violet and blue wavelengths. Single scattering albedos (SSA) of 0.94 and 0.99 were observed at 405 and 532 nm, respectively, for the same sample. Variability of these optical parameters will be discussed as a function of fuel and combustion conditions. Other real-time measurements included CO2, CO, NOx (NO and NO2), and SO2 concentrations, PM size-distributions, and PM and black carbon mass concentrations. In addition, Teflon-membrane, quartz-fiber, and Teflon-impregnated glass fiber (TIGF) filters followed by XAD-4 cartridges were collected for detailed chemical analysis.

  3. Ecological study of peat landforms in Canada and Alaska

    NASA Technical Reports Server (NTRS)

    Glaser, Paul H.

    1989-01-01

    Over 20 percent of the land surface of Canada and Alaska is covered by peatlands, which may be defined as any waterlogged ecosystem with a minimum thickness of 20 cm of organic matter in the soil. Past investigations have demonstrated the value of aerial photographs in identifying the major vegetation types and analyzing the biotic and hydrogeologic processes that control the development of these peatlands. In the present study, LANDSAT TM imagery was used in conjunction with field studies to determine the utility of this satellite sensor for detecting these important processes. Although the vegetation landforms within these major peat basins are visible on aerial photographs, LANDSAT TM imagery provides essential new evidence for their analysis. Spectral data from the LANDSAT TM system provides: (1) synoptic views of the patterns across large portions of these peat basins, indicating important physiographic controls on peatland development, (2) more sensitive detection of the major vegetation types, allowing rapid quantitative estimates to be made of their distribution and aerial extent, (3) discrimination of bog areas with potentially rapid or slow rates of peat accumulation, (4) identification of discharge zones for groundwater, which apparently represents the most important source of alkalinity in these peat basins, and (5) detection of flow patterns in water tracks that appear nearly uniform on standard aerial photographs.

  4. Classifying and mapping wetlands and peat resources using digital cartography

    USGS Publications Warehouse

    Cameron, Cornelia C.; Emery, David A.

    1992-01-01

    Digital cartography allows the portrayal of spatial associations among diverse data types and is ideally suited for land use and resource analysis. We have developed methodology that uses digital cartography for the classification of wetlands and their associated peat resources and applied it to a 1:24 000 scale map area in New Hampshire. Classifying and mapping wetlands involves integrating the spatial distribution of wetlands types with depth variations in associated peat quality and character. A hierarchically structured classification that integrates the spatial distribution of variations in (1) vegetation, (2) soil type, (3) hydrology, (4) geologic aspects, and (5) peat characteristics has been developed and can be used to build digital cartographic files for resource and land use analysis. The first three parameters are the bases used by the National Wetlands Inventory to classify wetlands and deepwater habitats of the United States. The fourth parameter, geological aspects, includes slope, relief, depth of wetland (from surface to underlying rock or substrate), wetland stratigraphy, and the type and structure of solid and unconsolidated rock surrounding and underlying the wetland. The fifth parameter, peat characteristics, includes the subsurface variation in ash, acidity, moisture, heating value (Btu), sulfur content, and other chemical properties as shown in specimens obtained from core holes. These parameters can be shown as a series of map data overlays with tables that can be integrated for resource or land use analysis.

  5. Peat Depth Assessment Using Airborne Geophysical Data for Carbon Stock Modelling

    NASA Astrophysics Data System (ADS)

    Keaney, Antoinette; McKinley, Jennifer; Ruffell, Alastair; Robinson, Martin; Graham, Conor; Hodgson, Jim; Desissa, Mohammednur

    2013-04-01

    The Kyoto Agreement demands that all signatory countries have an inventory of their carbon stock, plus possible future changes to this store. This is particularly important for Ireland, where some 16% of the surface is covered by peat bog. Estimates of soil carbon stores are a key component of the required annual returns made by the Irish and UK governments to the Intergovernmental Panel on Climate Change. Saturated peat attenuates gamma-radiation from underlying rocks. This effect can be used to estimate the thickness of peat, within certain limits. This project examines this relationship between peat depth and gamma-radiation using airborne geophysical data generated by the Tellus Survey and newly acquired data collected as part of the EU-funded Tellus Border project, together encompassing Northern Ireland and the border area of the Republic of Ireland. Selected peat bog sites are used to ground truth and evaluate the use of airborne geophysical (radiometric and electromagnetic) data and validate modelled estimates of soil carbon, peat volume and depth to bedrock. Data from two test line sites are presented: one in Bundoran, County Donegal and a second line in Sliabh Beagh, County Monaghan. The plane flew over these areas at different times of the year and at a series of different elevations allowing the data to be assessed temporally with different soil/peat saturation levels. On the ground these flight test lines cover varying surface land use zones allowing future extrapolation of data from the sites. This research applies spatial statistical techniques, including uncertainty estimation in geostatistical prediction and simulation, to investigate and model the use of airborne geophysical data to examine the relationship between reduced radioactivity and peat depth. Ground truthing at test line locations and selected peat bog sites involves use of ground penetrating radar, terrestrial LiDAR, peat depth probing, magnetometry, resistivity, handheld gamma-ray spectrometry, moisture content and rainfall monitoring combined with a real-time Differential Global Positioning System (DGPS) to monitor temporal and spatial variability of bog elevations. This research will assist in determining the accuracy and limitations of modelling soil carbon and changes in peat stocks by investigating the attenuation of gamma-radiation from underlying rocks. Tellus Border is supported by the EU INTERREG IVA programme, which is managed by the Special EU Programmes Body in Northern Ireland, the border Region of Ireland and western Scotland. The Tellus project was funded by the Northern Ireland Development of Enterprise Trade and Investment and by the Rural Development Programme through the Northern Ireland Programme for Building Sustainable Prosperity.

  6. Peat accumulation in drained thermokarst lake basins in continuous, ice-rich permafrost, northern Seward Peninsula, Alaska

    NASA Astrophysics Data System (ADS)

    Grosse, G.; Jones, M. C.; Jones, B.; Walter Anthony, K.

    2011-12-01

    Thermokarst lakes and peat-accumulating drained lake basins cover a substantial portion of Arctic lowland landscapes, yet the role of thermokarst lake drainage and ensuing peat formation in landscape-scale carbon (C) budgets remains understudied. We use measurements of terrestrial peat thickness, bulk density, organic matter content, and basal radiocarbon age from permafrost cores, soil pits, and exposures in vegetated, drained lake basins on the northern Seward Peninsula (Alaska) to characterize regional lake drainage chronology, C accumulation rates, and the role of thermokarst-lake cycling in carbon dynamics throughout the Holocene. Peat accumulation rates were highest in young (50-500 years) drained lake basins (35.2 g C m-2 yr-1) and decreased exponentially with time since drainage to 9 g C m-2 yr-1 in the oldest basins. Spatial analyses of terrestrial peat depth, basal peat radiocarbon ages, basin geomorphology, and satellite-derived land surface properties (Normalized Difference Vegetation Index, NDVI; Minimum Noise Fraction, MNF) from Landsat satellite data revealed significant relations between peat thickness and mean basin NDVI or MNF. By upscaling observed relations we infer that drained thermokarst lake basins, covering 391 km2 (76%) of the 515 km2 study region, store 6.4-6.6 Tg organic C in terrestrial peat of drained lake basins. Peat accumulation in drained lake basins likely serves as a negative feedback to greenhouse gas release from thermokarst-impacted landscapes.

  7. Thermal degradation of diesel-contaminated peats in an air atmosphere

    SciTech Connect

    Ghaly, R.A.; Ugursal, V.I.; Ghaly, A.E.; Mansaray, K.G.

    1999-06-01

    Peat, plant matter that is partially fossilized, is formed in poorly oxygenated wetlands where the rate at which the plant matter accumulates is greater than the rate at which it decomposes. Peat is a common solid fuel ranked among coal, coke, wood, and sugarcane bagasse. Peat has also been used to recover oil during the soil and water remediation processes. However, industrial utilization of peat in thermochemical conversion systems to liberate energy requires the knowledge of its thermal characteristics. In this study, the thermal behavior of peat (both uncontaminated and diesel-contaminated) was examined at three heating rates (10, 20, and 50 C/min) in a stationary air atmosphere using a thermogravimetric analysis technique between ambient temperature (25 C) and 600 C. The thermal degradation rate in active and passive pyrolysis zones, the initial degradation temperature, and the residual weight at 600 C were determined. Increasing the heating rate increased both the thermal degradation rate and the residual weight at 600 C and decreased the initial degradation temperature. The residual weight at 600 C was less than the ash content in all of the peat samples indicating the burnout of some of the mineral oxides, which have low melting and boiling temperatures, such as K{sub 2}O and P{sub 2}O. The results provide useful information about utilization of diesel-contaminated peat in thermochemical conversion systems, especially gasifiers, because of its high energy content and low ash content.

  8. Coarse Woody Debris Increases Microbial Community Functional Diversity but not Enzyme Activities in Reclaimed Oil Sands Soils.

    PubMed

    Kwak, Jin-Hyeob; Chang, Scott X; Naeth, M Anne; Schaaf, Wolfgang

    2015-01-01

    Forest floor mineral soil mix (FMM) and peat mineral soil mix (PMM) are cover soils commonly used for upland reclamation post open-pit oil sands mining in northern Alberta, Canada. Coarse woody debris (CWD) can be used to regulate soil temperature and water content, to increase organic matter content, and to create microsites for the establishment of microorganisms and vegetation in upland reclamation. We studied the effects of CWD on soil microbial community level physiological profile (CLPP) and soil enzyme activities in FMM and PMM in a reclaimed landscape in the oil sands. This experiment was conducted with a 2 (FMM vs PMM) × 2 (near CWD vs away from CWD) factorial design with 6 replications. The study plots were established with Populus tremuloides (trembling aspen) CWD placed on each plot between November 2007 and February 2008. Soil samples were collected within 5 cm from CWD and more than 100 cm away from CWD in July, August and September 2013 and 2014. Microbial biomass was greater (p<0.05) in FMM than in PMM, in July, and August 2013 and July 2014, and greater (p<0.05) near CWD than away from CWD in FMM in July and August samplings. Soil microbial CLPP differed between FMM and PMM (p<0.01) according to a principal component analysis and CWD changed microbial CLPP in FMM (p<0.05) but not in PMM. Coarse woody debris increased microbial community functional diversity (average well color development in Biolog Ecoplates) in both cover soils (p<0.05) in August and September 2014. Carbon degrading soil enzyme activities were greater in FMM than in PMM (p<0.05) regardless of distance from CWD but were not affected by CWD. Greater microbial biomass and enzyme activities in FMM than in PMM will increase organic matter decomposition and nutrient cycling, improving plant growth. Enhanced microbial community functional diversity by CWD application in upland reclamation has implications for accelerating upland reclamation after oil sands mining. PMID:26618605

  9. Coarse Woody Debris Increases Microbial Community Functional Diversity but not Enzyme Activities in Reclaimed Oil Sands Soils

    PubMed Central

    Kwak, Jin-Hyeob; Chang, Scott X.; Naeth, M. Anne; Schaaf, Wolfgang

    2015-01-01

    Forest floor mineral soil mix (FMM) and peat mineral soil mix (PMM) are cover soils commonly used for upland reclamation post open-pit oil sands mining in northern Alberta, Canada. Coarse woody debris (CWD) can be used to regulate soil temperature and water content, to increase organic matter content, and to create microsites for the establishment of microorganisms and vegetation in upland reclamation. We studied the effects of CWD on soil microbial community level physiological profile (CLPP) and soil enzyme activities in FMM and PMM in a reclaimed landscape in the oil sands. This experiment was conducted with a 2 (FMM vs PMM) × 2 (near CWD vs away from CWD) factorial design with 6 replications. The study plots were established with Populus tremuloides (trembling aspen) CWD placed on each plot between November 2007 and February 2008. Soil samples were collected within 5 cm from CWD and more than 100 cm away from CWD in July, August and September 2013 and 2014. Microbial biomass was greater (p<0.05) in FMM than in PMM, in July, and August 2013 and July 2014, and greater (p<0.05) near CWD than away from CWD in FMM in July and August samplings. Soil microbial CLPP differed between FMM and PMM (p<0.01) according to a principal component analysis and CWD changed microbial CLPP in FMM (p<0.05) but not in PMM. Coarse woody debris increased microbial community functional diversity (average well color development in Biolog Ecoplates) in both cover soils (p<0.05) in August and September 2014. Carbon degrading soil enzyme activities were greater in FMM than in PMM (p<0.05) regardless of distance from CWD but were not affected by CWD. Greater microbial biomass and enzyme activities in FMM than in PMM will increase organic matter decomposition and nutrient cycling, improving plant growth. Enhanced microbial community functional diversity by CWD application in upland reclamation has implications for accelerating upland reclamation after oil sands mining. PMID:26618605

  10. Genetic Differentiation Revealed by Selective Loci of Drought-Responding EST-SSRs between Upland and Lowland Rice in China

    PubMed Central

    Xia, Hui; Zheng, Xiaoguo; Chen, Liang; Gao, Huan; Yang, Hua; Long, Ping; Rong, Jun; Lu, Baorong; Li, Jiajia; Luo, Lijun

    2014-01-01

    Upland and lowland rice (Oryza sativa L.) represent two of the most important rice ecotypes adapted to ago-ecosystems with contrasting soil-water conditions. Upland rice, domesticated in the water-limited environment, contains valuable drought-resistant characters that can be used in water-saving breeding. Knowledge about the divergence between upland and lowland rice will provide valuable cues for the evolution of drought-resistance in rice. Genetic differentiation between upland and lowland rice was explored by 47 Simple Sequence Repeats (SSRs) located in drought responding expressed sequence tags (ESTs) among 377 rice landraces. The morphological traits of drought-resistance were evaluated in the field experiments. Different outlier loci were detected in the japonica and indica subspecies, respectively. Considerable genetic differentiation between upland and lowland rice on these outlier loci was estimated in japonica (Fst = 0.258) and indica (Fst = 0.127). Furthermore, populations of the upland and lowland ecotypes were clustered separately on these outlier loci. A significant correlation between genetic distance matrices and the dissimilarity matrices of drought-resistant traits was determined, indicating a certain relationship between the upland-lowland rice differentiation and the drought-resistance. Divergent selections occur between upland and lowland rice on the drought-resistance as the Qsts of some drought-resistant traits are significantly higher than the neutral Fst. In addition, the upland- and lowland-preferable alleles responded differently among ecotypes or allelic types under osmotic stress. This shows the evolutionary signature of drought resistance at the gene expression level. The findings of this study can strengthen our understanding of the evolution of drought-resistance in rice with significant implications in the improvement of rice drought-resistance. PMID:25286109

  11. Pollution in the upland environment.

    PubMed

    Crossley, A; Wilson, D B; Milne, R

    1992-01-01

    As part of a study on the effects of pollutants on forests, a long-term monitoring programme has been operating at two sites (602 and 275 m above sea level (a.s.l.)) in Glentress Forest, south-east Scotland, since June 1987. At these sites, equipment has been recording 20-min data for weather parameters, and cloud and rain event frequency, duration and intensity. The chemical composition of bulk cloud and rainwater has been measured. Cloudwater detection and collection has been made using passive 'Harp wire' gauges (with a cross-sectional area of 0.047 m2) strung with polypropylene filament and having a typical collection efficiency of 29% when compared with independent measurements of windspeed and liquid water content. During 1988, the annual rainfall at the upper site was 1213 mm, occurring over 1776 h. The equivalent cloudwater deposition to a forest with a drag coefficient of 0.06 was estimated to be 375 mm over 1936 h. A 'typical cloud event' lasted 4.5 h and would deposit to forests at a rate of 0.2 mm h(-1). There were significantly higher loadings of suspended particulate material (> 0.2 microm) in cloudwater (mean 18.42, max. 94.5 mg litre(-1)) compared with rainwater (mean 2.6, max. 25.6 mg litre(-1)). There were similar differences in ion concentrations, e.g. for H+ in cloudwater (mean 163, max. 1259 microm) and in rainwater (mean 33, max. 262 microM). It is concluded that cloudwater deposition represents a major pathway for pollutant transfer to the upland environment, especially where the surface vegetation is efficient at capturing cloudwater, i.e. forests. The consequences of this increased pollutant loading to forests and water catchments are yet to be assessed. PMID:15092053

  12. Utilization of peat as a fuel

    SciTech Connect

    Clemens, D.F.; Evans, G.O. II; Whitehurst, B.M.

    1981-10-01

    This work has dealt primarily with the development and evaluation of peat/No. 2 fuel oil mixtures (POM) and peat/methanol mixtures (PAM). POM and PAM slurries with varied peat loadings, peat moisture contents, and peat particle sizes have been studied by measuring slurry sedimentation ratios in jacketed glass tubes and slurry drain times from the tubes along with the slurry viscosities. The peat moisture content was found to be especially critical in forming stable slurries. Also, in both the PAM and POM systems, it was found that use of the more finely ground peat led to significantly higher sedimentation ratios than the use of coarse peat. Numerous additives selected to improve slurry suspension and flow characteristics have been evaluated. Cab-O-Sil M-5 and Cab-O-Sil PTG were most effective in the POM systems while Attagel X-2059 and Bentone 27 were most effective in the PAM systems. Viscosities have been measured for slurries of varied particle size and modified by selected additives. Viscosities in the PAM system were lower using the coarser peat with higher moisture content while viscosities in the POM system seemed to be lower using the finer, drier peat. Calorimetric studies of powdered peat as well as PAM and POM slurries, with and without additives, were completed. Combustion tests of POM and PAM slurries were carried out using a salamander type shop heater. Successful burns of the POM slurry were accomplished when the slurries were heated to reduce viscosities and the peat was prescreened to remove large wood fibers to avoid plugging of the small burner nozzle. Since the toxicity and low flash point of methanol precluded heating of the PAM slurries, plugging of the small burner routinely occurred. It was also demonstrated that ground peat could be burned by using an eductor connector to a compressed air line.

  13. PwC's 3-Peat

    ERIC Educational Resources Information Center

    Freifeld, Lorri

    2010-01-01

    PricewaterhouseCoopers (PwC) is giving the Chicago Bulls a run for their money when it comes to three-peats. The professional services firm scored the top spot on the Training Top 125 for a record third year in a row. So, just how did PwC nail No. 1 again? For starters, it met and exceeded a hefty challenge in fiscal year 2009: cutting training

  14. PwC's 3-Peat

    ERIC Educational Resources Information Center

    Freifeld, Lorri

    2010-01-01

    PricewaterhouseCoopers (PwC) is giving the Chicago Bulls a run for their money when it comes to three-peats. The professional services firm scored the top spot on the Training Top 125 for a record third year in a row. So, just how did PwC nail No. 1 again? For starters, it met and exceeded a hefty challenge in fiscal year 2009: cutting training…

  15. Soil Core Sample #2

    USGS Multimedia Gallery

    Soil core obtained from existing goose grazing lawn along the Smith River in the Teshekpuk Lake Special Area of the National Petroleum Reserve - Alaska.  Buried peat layer broken open.  Closer examination of the buried peat layer demonstrates that non-salt-tolerant vegetation from the past...

  16. Pore water chemistry in a disturbed and an undisturbed peat forests in Brunei Darussalam: Nutrient and carbon contents

    NASA Astrophysics Data System (ADS)

    Gandois, L.; Cobb, A.; Abu Salim, K.; Chieng Hei, I.; Lim Biaw Leng, L.; Corlett, R.; Harvey, C.

    2010-12-01

    Tropical peat swamp forests in their natural state are important reservoir of biodiversity, carbon and water. However, they are rapidly vanishing due to agricultural conversion (mainly to oil palms), logging, drainage and fire. Peat swamp forests constitute an important contribution to global and regional biodiversity, providing an habitat to rare and threatened species. They encompass a sequence of forest types from the perimeter to the center of mildely elevated domes, and at our site in Brunei, are host to Shorea Albida trees (Anderson, 1983). They constitute a large terrestrial carbon reservoir (tropical peat soils contain up to 70 Pg C, which accounts for 20% of global peat soil carbon and 2% of the global soil carbon (Hirano et al., 2007)). In tropical peat swamp forests, the most important factors controling organic matter accumulation, as well as the biodiversity and structure of the forest, are hydrology and nutrients availability (Page et al., 1999). Study of pore water in peat swamp forest can provide key information on carbon cycle, including biomass production, organic matter decomposition and leaching of carbon in draining water. However, data on pore water chemistry and nutrient concentrations in pristine tropical peatlands, as well as the effect of forest exploitation are scarce. The study area is located in the Belait district in Brunei Darussalam in Borneo Island. Brunei is perhaps the best of the regional guardians of peat forest systems; potentially irreversible damage to peat forest ecosystems has been widespread elsewhere. Two sites, one pristine dome and a logging concession, are being investigated. In order to assess the chemical status of the peat soil, pore water is sampled at different depth along the dome radius. The chemistry of pore water, including pH, conductivity, dissolved oxygen, concentration of major elements, as well as organic carbon content and properties are analyzed. References: Anderson, 1983. The tropical peat swamp of western malesia. Ecosystems of the world 4b, 181-189. Hirano et al., 2007. Carbon dioxide balance of a tropical peat swamp forest in Kalimantan, Indonesia. Global Change Biology 13, 412-425. Page et al., 1999. Interdependance of peat and vegetation in a tropical peat swamp forest. Phil. Trans. R. Soc. Lond. 354, 1885-1897.

  17. Content of lipids in finnish peat mires

    SciTech Connect

    Fagernaes, L.; Ekman, R.

    1985-01-01

    Peat is a potential raw material for chemical products. Peat extracts, bitumens, obtained from peat with neutral organic solvents, and, in particular, their wax fractions have been of interest with regard to their substituting for other natural waxes. Yields and characteristics of peat extracts have been studied by numerous researchers and acid and saponification values, molecular weights and elements analyses have been determined since the 1930s. New analytical methods have recently been introduced and made it possible to determine the amount and detailed composition of the lipid components of peat extracts by capillary gas chromatography (GC) and mass spectrometry. The aim of this study was to determine the yield and lipid composition of extracts from peat samples collected from different mires in Finland.

  18. Freshwater peat on the continental shelf

    USGS Publications Warehouse

    Emery, K.O.; Wigley, R.L.; Bartlett, A.S.; Rubin, M.; Barghoorn, E.S.

    1967-01-01

    Freshwater peats from the continental shelf off northeastern United States contain the same general pollen sequence as peats from ponds that are above sea level and that are of comparable radiocarbon ages. These peats indicate that during glacial times of low sea level terrestrial vegetation covered the region that is now the continental shelf in an unbroken extension from the adjacent land areas to the north and west.

  19. Smouldering fires and environmental reconstructions using ombrotrophic peat cores

    NASA Astrophysics Data System (ADS)

    Zaccone, Claudio; Rein, Guillermo; Ciavatta, Claudio; Knicker, Heike; Shotyk, William; Miano, Teodoro M.

    2014-05-01

    Peatlands are the soil organic matter-rich ecosystem most affected by fire. When they burn, the dominating phenomenon is not flaming but rather smouldering combustion. Recent estimates suggest that mean annual greenhouse gas emissions from smouldering peat fires are equivalent to 15% of global anthropogenic emissions. Furthermore, warmer temperatures at high latitudes are already resulting in unprecedented permafrost thaw, leaving large organic C pools exposed to fires for the first time in millennia. Much of our knowledge of past fire events is based on the abundance of charcoal particles in fossil and sub-fossil records. The combustion of char by the smouldering process implies that the record of past fires in peat cores may be entirely hidden. Three Sphagnum peat columns (26 cm deep) having different initial moisture contents (MC, in dry weight basis), i.e., 50, 100 and 200%MC, were prepared for this study. In a previous work, we tried to identify palaeofires by the physical and chemical signature that they leave behind in the soil profile. In the present one, we employ solid-state Nuclear Magnetic Resonance (NMR) and Isotope-Ratio Mass Spectroscopy (IRMS) characterization of peat organic matter, as well as results regarding and measure polycyclic aromatic hydrocarbons (PAH) production and metal concentration changes following smouldering fires. The 15N spectrum of fresh peat (FP) used as control shows only an amide signal, which is in agreement with the 13C NMR spectrum where mainly signals of carbohydrates and alkyl C can be observed. Further signals can be observed in the aromatic region, most probably due to lignin derivatives. Following the smouldering event, selected peat samples from both the 50% and 100% MC series show signals supporting the occurrence of fire. In detail, the 15N-signals between -200 and -250 ppm are typical for pyrrole or indole type N. This is in accordance with the 13C NMR spectra showing considerable intensity in the aromatic region, most likely from char residues. The isotopic signature of δ13C seems to be slightly affected by smouldering, although the information about vegetational changes are preserved, whereas the δ15N shows a trend positively correlated with the relative N enrichment observed in smouldered peat samples, as also supported by 15N NMR. Compared to flaming fires, smouldering fires produce much lower concentrations of PAH. Furthermore, PAH detected in peat following smouldering fires consist mainly of those with lower molecular weights (i.e., naphthalene, acenaphthene and fluorene). Finally, although concentrations of As, Hg, and Pb increase compared to the FP, their enrichment, relative to Ti, decreases. Such a trend regards mainly the surface layers. These data that suggest smouldering fires may be an important cause of variations observed in peat cores.

  20. Biosorption of Metallic Elements onto Fen Peat

    NASA Astrophysics Data System (ADS)

    Krumins, Janis; Robalds, Artis

    2014-12-01

    Industrial development and anthropogenic activity have a huge impact on the environment, forcing society to find new and cost-effective environment treatment technologies. One of the most effective and environmentally friendly methods is the use of biosorbents, for which peat is one of the most cost-effective materials. The adsorption capabilities of peat sediments are well known; however, mainly raised bog peat is used for environmental treatment, and thus the abilities of fen peat are underestimated. The aim of this research was to assess the fen peat suitability as an adsorbent for metallic elements. In this study we have determined the sorption characteristics of Ca, Mg, K, Na, Cu and Pb and results show that fen peat deposits have a huge variability as a biosorbent due to their variable botanical composition and complex properties, for instance, under equal conditions, wood-sedge peat can have higher lead adsorption capacity than wood peat. However, due to its natural content of metallic elements, the sorption capacity overall is lower than it is for raised bog peat, although the high pH reaction encourage a high mobility metals.

  1. 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

  2. 7 CFR 1427.103 - Upland cotton Domestic User Agreement.

    Code of Federal Regulations, 2010 CFR

    2010-01-01

    ... 7 Agriculture 10 2010-01-01 2010-01-01 false Upland cotton Domestic User Agreement. 1427.103... CORPORATION, DEPARTMENT OF AGRICULTURE LOANS, PURCHASES, AND OTHER OPERATIONS COTTON Economic Adjustment Assistance to Users of Upland Cotton § 1427.103 Upland cotton Domestic User Agreement. (a) Payments...

  3. 7 CFR 1427.103 - Upland cotton Domestic User Agreement.

    Code of Federal Regulations, 2012 CFR

    2012-01-01

    ... 7 Agriculture 10 2012-01-01 2012-01-01 false Upland cotton Domestic User Agreement. 1427.103... CORPORATION, DEPARTMENT OF AGRICULTURE LOANS, PURCHASES, AND OTHER OPERATIONS COTTON Economic Adjustment Assistance to Users of Upland Cotton § 1427.103 Upland cotton Domestic User Agreement. (a) Payments...

  4. 7 CFR 1427.101 - Eligible upland cotton.

    Code of Federal Regulations, 2011 CFR

    2011-01-01

    ... 7 Agriculture 10 2011-01-01 2011-01-01 false Eligible upland cotton. 1427.101 Section 1427.101... OF AGRICULTURE LOANS, PURCHASES, AND OTHER OPERATIONS COTTON Economic Adjustment Assistance to Users of Upland Cotton § 1427.101 Eligible upland cotton. (a) For purposes of this subpart, eligible...

  5. 7 CFR 1427.101 - Eligible upland cotton.

    Code of Federal Regulations, 2012 CFR

    2012-01-01

    ... 7 Agriculture 10 2012-01-01 2012-01-01 false Eligible upland cotton. 1427.101 Section 1427.101... OF AGRICULTURE LOANS, PURCHASES, AND OTHER OPERATIONS COTTON Economic Adjustment Assistance to Users of Upland Cotton § 1427.101 Eligible upland cotton. (a) For purposes of this subpart, eligible...

  6. 7 CFR 1427.101 - Eligible upland cotton.

    Code of Federal Regulations, 2014 CFR

    2014-01-01

    ... 7 Agriculture 10 2014-01-01 2014-01-01 false Eligible upland cotton. 1427.101 Section 1427.101... OF AGRICULTURE LOANS, PURCHASES, AND OTHER OPERATIONS COTTON Economic Adjustment Assistance to Users of Upland Cotton § 1427.101 Eligible upland cotton. (a) For purposes of this subpart, eligible...

  7. 7 CFR 1427.103 - Upland cotton Domestic User Agreement.

    Code of Federal Regulations, 2014 CFR

    2014-01-01

    ... 7 Agriculture 10 2014-01-01 2014-01-01 false Upland cotton Domestic User Agreement. 1427.103... CORPORATION, DEPARTMENT OF AGRICULTURE LOANS, PURCHASES, AND OTHER OPERATIONS COTTON Economic Adjustment Assistance to Users of Upland Cotton § 1427.103 Upland cotton Domestic User Agreement. (a) Payments...

  8. 7 CFR 1427.101 - Eligible upland cotton.

    Code of Federal Regulations, 2013 CFR

    2013-01-01

    ... 7 Agriculture 10 2013-01-01 2013-01-01 false Eligible upland cotton. 1427.101 Section 1427.101... OF AGRICULTURE LOANS, PURCHASES, AND OTHER OPERATIONS COTTON Economic Adjustment Assistance to Users of Upland Cotton § 1427.101 Eligible upland cotton. (a) For purposes of this subpart, eligible...

  9. 7 CFR 1427.101 - Eligible upland cotton.

    Code of Federal Regulations, 2010 CFR

    2010-01-01

    ... 7 Agriculture 10 2010-01-01 2010-01-01 false Eligible upland cotton. 1427.101 Section 1427.101... OF AGRICULTURE LOANS, PURCHASES, AND OTHER OPERATIONS COTTON Economic Adjustment Assistance to Users of Upland Cotton § 1427.101 Eligible upland cotton. (a) For purposes of this subpart, eligible...

  10. 7 CFR 1427.103 - Upland cotton Domestic User Agreement.

    Code of Federal Regulations, 2013 CFR

    2013-01-01

    ... 7 Agriculture 10 2013-01-01 2013-01-01 false Upland cotton Domestic User Agreement. 1427.103... CORPORATION, DEPARTMENT OF AGRICULTURE LOANS, PURCHASES, AND OTHER OPERATIONS COTTON Economic Adjustment Assistance to Users of Upland Cotton § 1427.103 Upland cotton Domestic User Agreement. (a) Payments...

  11. 7 CFR 1427.103 - Upland cotton Domestic User Agreement.

    Code of Federal Regulations, 2011 CFR

    2011-01-01

    ... 7 Agriculture 10 2011-01-01 2011-01-01 false Upland cotton Domestic User Agreement. 1427.103... CORPORATION, DEPARTMENT OF AGRICULTURE LOANS, PURCHASES, AND OTHER OPERATIONS COTTON Economic Adjustment Assistance to Users of Upland Cotton § 1427.103 Upland cotton Domestic User Agreement. (a) Payments...

  12. Microelements in Lowland Peat of the Northeastern Part of the Altai Mountains

    NASA Astrophysics Data System (ADS)

    Shurova, M. V.; Larina, G. V.; Kozlova, S. A.; Shagaeva, L. L.

    2010-05-01

    The greatest areas of bogs are concentrated in the northeastern part of Altai Republic. This place due to a great amount of precipitation and a powerful accumulation of snow with a little drain in comparison with other areas has plenty of bogs. A quarter of all bogs of the Altai Mountains is concentrated here. The bogs develop mainly in the valleys of the rivers. The bogs have a modern origin and the process of bog formation goes at the present time by overgrowing of oxbow and valley lakes, and also by bogging of dry lands - woods and meadows. The area of bogs in relation to the general territory of highlands makes up 1%. Nevertheless, these territories are regarded as complex ecosystems which have economic and scientific value. Let's consider the content of heavy metals in different horizons of the peat under study. The samples of peat of the deposit being examined are characterized by a low total content of zinc: 6,21-44,12 mg/kg. The average amount of zinc in the soils of the Altai Mountains is much larger and makes up 70,3 mg/kg. Quite a significant amount of copper is washed away from peat thickness, its total amount is at the level of 1,58-10,73 mg/kg. The reason for it, probably, lies in the fact that there is a significant amount of fulvic acids in the composition of humic acids which enable the migration of copper beyond the limits of the peat ground in the conditions of the sour environment. A completely different situation is observed in the soils of the Altai mountain area. The biogeochemistry of copper in the soils of the Altai Mountains is thoroughly investigated by M.A.Malgin, A.V.Puzanov, O.A.Yelchininova. Its average amount in the soils of the Altai Mountains makes up 40,6 mg/kg which is twice as much as the abundance ratio in comparison with the world soils. The authors explain this fact as follows: copper is an inactive element in the soils since its ions are easily precipitated by sulfide-, carbonate-, and hydroxide ions, and also are taken up by humic acids of soils. Therefore, notwithstanding the washing type of a water mode, the leaching of copper from the soils of the Altai Mountains is not observed. The amount of cadmium in the investigated lowland peat makes up from 0,12 up to 0,57 mg/kg which is almost two times less than the roughly allowable concentration. Also the monotonous increase of the concentration factor of cadmium upwards on the structure is observed. The peat of the surveyed deposit as far as the amount of cadmium is concerned is actually at the level of the background soils of the Altai mountain area. The amount of lead in the peat under study is not subject to significant fluctuation - from 1,34 up to 10,0 mg/kg which is lower than the average amount characteristic of the soils of the Altai Mountains. The roughly allowable concentration of lead for sour soils makes up 65 mg/kg, therefore the peat under study is non-polluting or lead-free. There is an even distribution of lead in the structure of the axial section. In the distribution of zinc, copper, cadmium, lead in peat thickness there is a contrast between the top layers and the bottom ones. The top layers are characterized by higher concentration of elements. The lowland peat of the northeastern part of Altai Republic in comparison with the West-Siberian peat is characterized by the increased values of zinc and has the same amount of copper and lead.

  13. Biochar from deinking paper sludge as a peat replacement in growing media preparation

    NASA Astrophysics Data System (ADS)

    Gil, Eva; Méndez, Ana; Paz-Ferreiro, Jorge; Fernández, José Manuel; Plaza, César; Gascó, Gabriel

    2015-04-01

    Nowadays, there is an important trend in Europe for peat replacement with biochar in growing media formulation in order to reduce the environmental impact of peat exploitation. One evidence is the the creation of a working group on peat replacement within the framework of an EU COST action Biochar as option for sustainable resource management funded by the European Union. The use of biochar can reduce the environmental impact peat uses and also it can diminish the economic cost of different growing media ingredients as coir, bark or green waste compost in soil-less cultivation. The objective of this work was to study the use of biochar from deinking paper sludge in the formulation of growing media. For this reason, peat and coir were replaced by prepared biochar. Hydrophysical and chemical properties of different substrates were tested. At the same time, plant growth assay was designed. Results shown that is possible to use biochar to replace peat in growing media formulation obtaining similar crop yields.

  14. 77 FR 19925 - Upland Cotton Base Quality

    Federal Register 2010, 2011, 2012, 2013, 2014

    2012-04-03

    ... Secretary of Agriculture effective July 24, 1971 (36 FR 13804) relating to notices of proposed rulemaking... on June 24, 1983 (48 FR 29115). Executive Order 12988 This rule has been reviewed under Executive... Corporation 7 CFR Part 1427 RIN 0560-AI16 Upland Cotton Base Quality AGENCY: Commodity Credit Corporation...

  15. Mars Meteorite Statistics and the Martian Uplands

    NASA Astrophysics Data System (ADS)

    Hartmann, W. K.

    2002-01-01

    A significant fraction of Mars, perhaps 30-50%, is covered by heavily cratered uplands. The high crater densities constrain their ages to be greater than 2 Gy or even 3 Gy. A somewhat smaller fraction is covered by young lava plains with crater retention ages less than 1.5 Gy, and even less than 0.5 Gy over wide areas of Tharsis, Amazonis, and Elysium. These young ages for basaltic lava plains agree with ages of Martian basaltic meteorites. The problem is that all but one of the 4 to 8 sample sites of SNCs lie in the age range of 0.2 to 1.3 Gy, and the other one is a sample of primordial crust of 4.5 Gy age. These data suggest that the Martian uplands do not efficiently launch meteorites. MGS and Odyssey data imply that the upper latitude Hesperian/Noachian Martian uplands, older than 2 to 3 Gy, are impregnated with near-surface ice. Furthermore, direct geometric considerations of crater areal coverage show that they have been pulverized into megaregolith, although that material itself may be recemented by salts, carbonates, and ice. Thus, the Martian uplands probably do not launch meteorites as effectively as the young basaltic plains, and those that are launched may be rich in rock types that are unfamiliar as meteorites. These considerations should affect future meteorite collection strategies.

  16. Peat Formation Processes During the Past 7000 Years in the Sacramento San Joaquin Delta, California, USA

    NASA Astrophysics Data System (ADS)

    Drexler, J. Z.; de Fontaine, C. S.; Brown, T. A.

    2008-12-01

    The 1,400 km2 tidal marsh that formed during the Holocene in the Sacramento--San Joaquin Delta was largely drained for agriculture during the past 150 years. The remaining peat constitutes an archive of marsh formation processes and environmental conditions through the millennia. The goals of the REPEAT (Rates and Evolution of Peat Accretion through Time) project are to determine past rates and processes of peat accretion to benefit future wetland restoration efforts. Peat cores were collected across the Delta during 2005 from drained, farmed islands and from remnant, marsh islands in the Delta. Radiocarbon analyses of plant macrofossils were used to construct age models for vertical peat profiles. Peat began forming approximately 6,600 calibrated years before present (cal yr BP). Over the last 150 years, approximately 2/3 of the original peat thickness on the farmed islands has been lost because of land-surface subsidence. On the marsh islands, estimated rates of vertical accretion range from 0.06 to 0.53 cm yr-1. Mean rates of vertical accretion at the marshes suggest that three out of the four marsh sites are capable of keeping pace with current rates of sea-level rise. Bulk density, % OM (organic matter), % contribution of OM vs. inorganic matter (IM) to soil volume, and vertical accretion rates show considerable variability through the millennia. Some variability is associated with a period of high precipitation and freshwater discharge between approximately 4,000 to 2,000 yr BP. The hydrogeomorphic setting of marshes appears to largely control the amount of IM incorporated into peat through time. Sediment supply will likely determine whether remnant and restored tidal marshes can keep pace with future sea-level rise in the Delta.

  17. Peat hybrid sorbents for treatment of wastewaters and remediation of polluted environment

    NASA Astrophysics Data System (ADS)

    Klavins, Maris; Burlakovs, Juris; Robalds, Artis; Ansone-Bertina, Linda

    2015-04-01

    For remediation of soils and purification of polluted waters, wastewaters, sorbents might be considered as an prospective group of materials and amongst them peat have a special role due to low cost, biodegradability, high number of functional groups, well developed surface area and combination of hydrophilic/hydrophobic structural elements. Peat as sorbent have good application potential for removal of trace metals, and we have demonstrated peat sorption capacities, sorption kinetics, thermodynamics in respect to metals with different valencies - Tl(I), Cu(II), Cr(III). However peat sorption capacity in respect to nonmetallic (anionic species) elements is low. Also peat mechanical properties do not support application in large scale column processes. To expand peat application possibilities the approach of biomass based hybrid sorbents has been elaborated. The concept "hybrid sorbent" in our understanding means natural, biomass based sorbent modified, covered with another sorbent material, thus combining two types of sorbent properties, sorbent functionalities, surface properties etc. As the "covering layer" both inorganic substances, mineral phases (iron oxohydroxides, oxyapatite) both organic polymers (using graft polymerization) were used. The obtained sorbents were characterised by their spectral properties, surface area, elemental composition. The obtained hybrid sorbents were tested for sorption of compounds in anionic speciation forms, for example of arsenic, antimony, tellurium and phosphorous compounds in comparison with weakly basic anionites. The highest sorption capacity was observed when peat sorbents modified with iron compounds were used. Sorption of different arsenic speciation forms onto iron-modified peat sorbents was investigated as a function of pH and temperature. It was established that sorption capacity increases with a rise in temperature, and the calculation of sorption process thermodynamic parameters indicates the spontaneity of sorption process and its endothermic nature. The recycling options of obtained compounds after their saturation with metal or non-metallic species are suggested. Acknowledgement: Support from a project 2014/0009/1DP/1.1.1.2.0/13/APIA/VIAA/044

  18. Self-organizing patterns of peat decomposition in mires and implications for greenhouse gas emissions

    NASA Astrophysics Data System (ADS)

    Plug, L. J.; Tae, K. E.; Werner, B. T.

    2004-12-01

    In many peatlands occurring in both permafrost and temperate terrain, vegetation develops in the form of spatially heterogeneous patterns or pools. Because GHG fluxes and their responses to allogenic forcing from different elements of mire patterns (eg., pools and raised peat strings) can vary, quantifying the role of peatlands in climate change may require using models for the dynamics of patterns. To this end, we investigate patterns of consistently-spaced ? 2 m diameter pools that occur in permafrost mires across a 4500 y chronosequence at Espenberg, NW Alaska. Pools first occur in small groups (<5) on 1200 y old mires where peat depth is ? 1 m, and pool patterns increase in size thereafter. Dissolved oxygen in pool water and peat stratigraphy in pool walls and floors are consistent with formation by peat decomposition amplified by thaw-derived subsidence of ice-rich organic soil. Natural patterns are reproduced by a model in which new pools principally initiate in ? 3 m wide annuli around existing pools, as evaluated using Kolmogorov-Smirnov tests of pool spacing distributions. Models encapsulating spatially random mechanisms for pool formation cannot reproduce natural patterns. Pool replication occurs by suppression of peat accumulation adjacent to 0.2--1.0 m high frost-heaved peat rings by drifting snow that persists into the growing season. Because pool initiation depends on distribution of earlier pools, rates and patterns of peat decomposition in the mire may nonlinearly depend upon, and have intrinsic time-scales exceeding, external influences on decomposition such as climate. Variations in peat accumulation or decomposition, and hence carbon accumulation or release, are localized in pools rather than occurring as a bulk change across a peatland surface. The influence of emergent pattern dynamics in this environment, and others, such as the patterned peatlands of Cape Breton, Nova Scotia, will be discussed.

  19. Altered peat hydrophysical properties following drainage and wildfire increases peatland vulnerability to ecosystem regime shift

    NASA Astrophysics Data System (ADS)

    Waddington, James; Kettridge, Nick; Sherwood, James; Granath, Gustaf

    2015-04-01

    Northern peatlands represent a globally significant carbon reservoir, composed largely of legacy carbon which is no longer part of the active carbon cycle. However, it is unclear whether this legacy carbon is vulnerable as a result of enhanced peat smouldering and combustion under the moderate drying conditions predicted for northern peatlands as a result of climate change and/or disturbance from forestry, mining, and associated transport development. A significant loss in legacy carbon as a result of wildfire has already been observed in smaller tropical peatlands where deep peat soils have been destabilized due to severe drainage and a shift in vegetation. Capitalizing on a unique long-term experiment, we quantify the post-wildfire recovery of a northern peatland several decades post drainage. We show that the moderate drop in water table position predicted for most northern regions triggers a shift in vegetation composition, previously observed within only severely disturbed tropical peatlands, when accompanied by wildfire. The combined impact of moderate drainage followed by wildfire resulted in a shift of the peat surface down the peat profile, exposing denser peat at the surface. In undisturbed northern peatlands where depth of burn is typically low, low-density near-surface peats help regulate water-table position and near-surface moisture availability post-fire, both of which are favourable to Sphagnum recolonization. As a result of drainage and fire at the study site, the self-regulating properties of the low-density Sphagnum surface were lost. We demonstrate that changes in peat hydrophysical properties increased hydrological limitations to Sphagnum recovery leading to the conversion to a non-carbon accumulating shrub-grass ecosystem. This new ecosystem is likely to experience a low intensity, high frequency wildfire regime, which will further deplete the legacy carbon stored in the peat.

  20. Assessment of the peat resources of Florida, with a detailed survey of the northern everglades

    SciTech Connect

    Griffin, G.M.; Wieland, C.C.; Hood, L.Q.; Goode, R.W. III; Sawyer, R.K.; McNeill, D.F.

    1982-01-01

    Available data, including previous publications, modern soil surveys, and detailed coring in the Northern Everglades for this project have been used to update information on Florida's peat resources. It is now estimated that Florida could, if no other constraints existed, produce 606 million tons of moisture-free fuel-grade peat, which may yield approximately 10.0 x 10/sup 15/ Btu of energy. These estimates are much lower than previously published projections for the state. The principal effort of this survey was in the largest peat region of the state, the Northern Everglades of Palm Beach and adjacent counties, where more than 800 core holes were drilled. Based on analyses of these cores, the Northern Everglades is now estimated to contain 191 million tons of moisture-free peat, with a potential energy yield of 2.98 x 10/sup 15/ Btu. These values are considerably less than previously published estimates, probably due to bacterial oxidation and other forms of drainage-induced subsidence in the Everglades agricultural areas. The present fuel-peat resources of the Northern Everglades occur in 19 separate deposits. Of these, the deposits in the Port Mayaca, Bryant, Six Mile Bend, and Loxahatchee Quadrangles comprise the highest concentration of the resource. These lands are generally privately owned and used for sugar cane and other crops, and the conversion of these lands to peat removal seems unlikely. It seems even less likely that the extensive peat deposits within the Loxahatchee National Wildlife Refuge will be available for fuel use, barring a dire national emergency. The utilization of peat as a fuel must be approached with caution and careful study; large scale use may require state or federal action. 34 references.

  1. South Florida wetlands ecosystem; biogeochemical processes in peat

    USGS Publications Warehouse

    Orem, William; U.S. Geological Survey

    1996-01-01

    The South Florida wetlands ecosystem is an environment of great size and ecological diversity (figs. 1 and 2). The landscape diversity and subtropical setting of this ecosystem provide a habitat for an abundance of plants and wildlife, some of which are unique to South Florida. South Florida wetlands are currently in crisis, however, due to the combined effects of agriculture, urbanization, and nearly 100 years of water management. Serious problems facing this ecosystem include (1) phosphorus contamination producing nutrient enrichment, which is causing changes in the native vegetation, (2) methylmercury contamination of fish and other wildlife, which poses a potential threat to human health, (3) changes in the natural flow of water in the region, resulting in more frequent drying of wetlands, loss of organic soils, and a reduction in freshwater flow to Florida Bay, (4) hypersalinity, massive algal blooms, and seagrass loss in parts of Florida Bay, and (5) a decrease in wildlife populations, especially those of wading birds. This U.S. Geological Survey (USGS) project focuses on the role of organic-rich sediments (peat) of South Florida wetlands in regulating the concentrations and impact of important chemical species in the environment. The cycling of carbon, nitrogen, phosphorus, and sulfur in peat is an important factor in the regulation of water quality in the South Florida wetlands ecosystem. These elements are central to many of the contamination issues facing South Florida wetlands, such as nutrient enrichment, mercury toxicity, and loss of peat. Many important chemical and biological reactions occur in peat and control the fate of chemical species in wetlands. Wetland scientists often refer to these reactions as biogeochemical processes, because they are chemical reactions usually mediated by microorganisms in a geological environment. An understanding of the biogeochemical processes in peat of South Florida wetlands will provide a basis for evaluating the effects on water quality of (1) constructing buffer wetlands to alleviate nutrient contamination and (2) replumbing the ecosystem to restore natural water flow. The results may also suggest new approaches for solving problems of contamination and water quality in these wetlands. A second focus of this project will be on the geochemical history of the South Florida ecosystem. Peat is a repository of the history of past environmental conditions in the wetland. Before effective action can be taken to correct many of the problems facing these wetlands, we must first study the biogeochemistry of the peat at depth in order to understand whether current problems are the result of recent human activity or are part of a long-term natural cycle. Coordination with other (USGS) projects for South Florida is ongoing. These projects are studying the biological history of the ecosystem by using pollen and shells buried in the peat, together with procedures for dating the peat at various depths, to develop an overall ecosystem history model, with emphasis on the last 100 years.

  2. Mineral resource of the month: peat

    USGS Publications Warehouse

    Jasinski, Stephen M.

    2008-01-01

    Peat is a natural organic material of botanical origin, harvested from deposits in bogs and fens. Commercial deposits form from the incomplete decomposition of plant matter under anaerobic conditions and gradually accumulate to form peat over about a 5,000-year period.

  3. Rhizosphere impacts on peat decomposition and nutrient cycling across a natural water table gradient

    NASA Astrophysics Data System (ADS)

    Gill, A. L.; Finzi, A.

    2014-12-01

    High latitude forest and peatland soils represent a major terrestrial carbon store sensitive to climate change. Warming temperatures and increased growing-season evapotranspiration are projected to reduce water table (WT) height in continental peatlands. WT reduction increases peat aerobicity and facilitates vascular plant and root growth. Root-associated microbial communities are exposed to a different physical and chemical environment than microbial communities in non-root associated "bulk" peat, and therefore have distinct composition and function within the soil system. As the size of the peatland rhizosphere impacts resources available to the microbial communities, transitions from a root-free high water table peatland to a root-dominated low WT peatland may alter seasonal patterns of microbial community dynamics, enzyme production, and carbon storage within the system. We used a natural water table gradient in Caribou Bog near Orono, ME to explore the influence of species composition, root biomass, and rhizosphere size on seasonal patterns in microbial community structure, enzyme production, and carbon mineralization. We quantified root biomass across the water table gradient and measured microbial biomass carbon and nitrogen, C mineralization, N mineralization, and exoenzyme activity in root-associated and bulk peat samples throughout the 2013 growing season. Microbial biomass was consistently higher in rhizosphere-associated soils and peaked in the spring. Microbial biomass CN and enzyme activity was higher in rhizosphere-associated soil, likely due to increased mycorrhizal abundance. Exoenzyme activity peaked in the fall, with a larger relative increase in enzyme activity in rhizosphere peat, while carbon mineralization rates did not demonstrate a strong seasonal pattern. The results suggest that rhizosphere-associated peat sustains higher and more variable rates of enzyme activity throughout the growing season, which results in higher rates of carbon mineralization driven by increased microbial biomass. Increases in vascular plant abundance and root biomass may therefore increase overall rates of carbon mineralization and peat decomposition within peatland systems and influence the nature of the peatland carbon store.

  4. Nitrate and sulphate dynamics in peat subjected to different hydrological conditions: Batch experiments and field comparison

    NASA Astrophysics Data System (ADS)

    Bougon, N.; Auterives, C.; Aquilina, L.; Marmonier, P.; Derrider, Jo; Vandenkoornhuyse, P.

    2011-12-01

    SummaryConservation of ecosystems that depend on water management and water quality has to be considered. We combined a field monitoring and batch experiments to better understand the impact of hydrological perturbations on peatland functioning. Factors influencing the dynamics of nitrate and sulphate concentration observed in two sites with different hydrological conditions in a south Normandy peatland were determined through the comparison of field and lab experiment. The effects of nitrate input, and oxic or anoxic conditions on nitrate and sulphate concentrations were investigated in bioreactors, using peat samples from field sites influenced by different hydrologic regimes. In this experiment, peat samples were subjected to similar conditions to address the effects of NO3- and O 2 concentrations (chemical effects), and the effect of hydrologic regimes and peat soil moisture (physical effects) on nitrate and sulphate dynamics. Cl -, SO42- and NO3- were monitored for 215 h. Nitrate was significantly reduced in most experiments. A complete nitrate reduction after 215 h in soil under anoxic conditions was observed. A denitrification process was also found under aerobic conditions depending on the peat site sampling, i.e. depending on the hydrological conditions. This process was interpreted as a heterotrophic denitrification. Sulphate monitoring revealed that 400 mg L -1 were produced in peat from the peat site with high hydrologic fluxes under aerobic conditions. Clear differences in chloride concentration (deviance analysis, P < 0.05), sulphate concentration and nitrate consumption dynamics (deviance analysis, P < 0.0001) were observed, for similar experimental chemical conditions, between the samples from the two peat sites. These differences were related to the field chemical variations observed and they indicate that part of the field nitrate and sulphate dynamics is linked to different bacterial activity and not only to nutrient fluxes variations.

  5. Lateral carbon fluxes and CO2 outgassing from a tropical peat-draining river

    NASA Astrophysics Data System (ADS)

    Müller, D.; Warneke, T.; Rixen, T.; Müller, M.; Jamahari, S.; Denis, N.; Mujahid, A.; Notholt, J.

    2015-07-01

    Tropical peatlands play an important role in the global carbon cycle due to their immense carbon storage capacity. However, pristine peat swamp forests are vanishing due to deforestation and peatland degradation, especially in Southeast Asia. CO2 emissions associated with this land use change might not only come from the peat soil directly, but also from peat-draining rivers. So far, though, this has been mere speculation, since there was no data from undisturbed reference sites. We present the first combined assessment of lateral organic carbon fluxes and CO2 outgassing from an undisturbed tropical peat-draining river. Two sampling campaigns were undertaken on the Maludam river in Sarawak, Malaysia. The river catchment is covered by protected peat swamp forest, offering a unique opportunity to study a peat-draining river in its natural state, without any influence from tributaries with different characteristics. The two campaigns yielded consistent results. Dissolved organic carbon (DOC) concentrations ranged between 3222 and 6218 μmol L-1 and accounted for more than 99 % of the total organic carbon (TOC). Radiocarbon dating revealed that the riverine DOC was of recent origin, suggesting that it derives from the top soil layers and surface runoff. We observed strong oxygen depletion, implying high rates of organic matter decomposition and consequently CO2 production. The measured median pCO2 was 7795 and 8400 μatm during the two campaigns, respectively. Overall, we found that only 26 ± 15 % of the carbon was exported by CO2 evasion, while the rest was exported by discharge. CO2 outgassing seemed to be moderated by the short water residence time. Since most Southeast Asian peatlands are located at the coast, this is probably an important limiting factor for CO2 outgassing from most of its peat-draining rivers.

  6. Lateral carbon fluxes and CO2 outgassing from a tropical peat-draining river

    NASA Astrophysics Data System (ADS)

    Müller, D.; Warneke, T.; Rixen, T.; Müller, M.; Jamahari, S.; Denis, N.; Mujahid, A.; Notholt, J.

    2015-10-01

    Tropical peatlands play an important role in the global carbon cycle due to their immense carbon storage capacity. However, pristine peat swamp forests are vanishing due to deforestation and peatland degradation, especially in Southeast Asia. CO2 emissions associated with this land use change might not only come from the peat soil directly but also from peat-draining rivers. So far, though, this has been mere speculation, since there has been no data from undisturbed reference sites. We present the first combined assessment of lateral organic carbon fluxes and CO2 outgassing from an undisturbed tropical peat-draining river. Two sampling campaigns were undertaken on the Maludam River in Sarawak, Malaysia. The river catchment is covered by protected peat swamp forest, offering a unique opportunity to study a peat-draining river in its natural state, without any influence from tributaries with different characteristics. The two campaigns yielded consistent results. Dissolved organic carbon (DOC) concentrations ranged between 3222 and 6218 μmol L-1 and accounted for more than 99 % of the total organic carbon (TOC). Radiocarbon dating revealed that the riverine DOC was of recent origin, suggesting that it derives from the top soil layers and surface runoff. We observed strong oxygen depletion, implying high rates of organic matter decomposition and consequently CO2 production. The measured median pCO2 was 7795 and 8400 μatm during the first and second campaign, respectively. Overall, we found that only 32 ± 19 % of the carbon was exported by CO2 evasion, while the rest was exported by discharge. CO2 outgassing seemed to be moderated by the short water residence time. Since most Southeast Asian peatlands are located at the coast, this is probably an important limiting factor for CO2 outgassing from most of its peat-draining rivers.

  7. Substitution of peat, fertiliser and manure by compost in hobby gardening: user surveys and case studies.

    PubMed

    Andersen, Jacob K; Christensen, Thomas H; Scheutz, Charlotte

    2010-12-01

    Four user surveys were performed at recycle centres (RCs) in the Municipalities of Aarhus and Copenhagen, Denmark, to get general information on compost use and to examine the substitution of peat, fertiliser and manure by compost in hobby gardening. The average driving distance between the users' households and the RCs was found to be 4.3 km and the average amount of compost picked up was estimated at 800 kg per compost user per year. The application layer of the compost varied (between 1 and 50 cm) depending on the type of use. The estimated substitution (given as a fraction of the compost users that substitute peat, fertiliser and manure with compost) was 22% for peat, 12% for fertiliser and 7% for manure (41% in total) from the survey in Aarhus (n=74). The estimate from the survey in Copenhagen (n=1832) was 19% for peat, 24% for fertiliser and 15% for manure (58% in total). This is the first time, to the authors' knowledge, that the substitution of peat, fertiliser and manure with compost has been assessed for application in hobby gardening. Six case studies were performed as home visits in addition to the Aarhus surveys. From the user surveys and the case studies it was obvious that the total substitution of peat, fertiliser and manure was not 100%, as is often assumed when assigning environmental credits to compost. It was more likely around 50% and thus there is great potential for improvement. It was indicated that compost was used for a lot of purposes in hobby gardening. Apart from substitution of peat, fertiliser and manure, compost was used to improve soil quality and as a filling material (as a substitute for soil). Benefits from these types of application are, however, difficult to assess and thereby quantify. PMID:20724134

  8. Monitoring the effects of manure policy in the Peat region, Netherlands

    NASA Astrophysics Data System (ADS)

    Hooijboer, Arno; Buis, Eke; Fraters, Dico; Boumans, Leo; Lukacs, Saskia; Vrijhoef, Astrid

    2014-05-01

    Total N concentrations in farm ditches in the Peat region of the Netherlands are on the average twice as high as the Good Ecological Potential value of the Water Framework Directive. Since ditches are connected to regional surface water, they may contribute to eutrophication. The minerals policy aims to improve the water quality. In the Netherlands, the effectiveness of the minerals policy on water quality is evaluated with data from the National Minerals Policy Monitoring Programme (LMM). This regards farm data on the quality of water leaching from the root zone and on farm practices. The soil balance nitrogen surpluses decreased between 1996 and 2003 on dairy farms in the Peat region. However, no effect on root zone leaching was found. This study aims to show how monitoring in the Peat region can be improved in order to link water quality to agricultural practice. Contrary to the other Dutch regions, nitrate concentrations in root zone leaching on farms in the Peat region are often very low (90% of the farms below 25 mg/l) due to the reduction of nitrate (denitrification). The main nitrogen (N) components in the peat region waters are ammonium and organic N. Total N is therefore a better measure for N concentrations in the Peat region. The ammonium concentration in groundwater in Dutch peat soils increases with depth. It is assumed that the deeper ammonia-rich water is older and relates to anaerobic peat decomposition instead of agricultural practice. Recent infiltrated low-ammonium water, lies like a thin freshwater lens on the older water. In the Peat region, root zone leaching is monitored by taking samples from the upper meter of groundwater. Unintended, often both lens water and older water are sampled and this distorts the relation between agricultural practice and water quality. In the Peat region, the N surplus is transported with the precipitation surplus to ditches. The relation between the N surplus and the total N in ditch water is therefore better than between N surplus and total N in root zone leaching. The precipitation surplus flows to ditches directly or via open field drains. However, the ditches may be fed partly with older water (seepage of groundwater). In the open field drain only recent water will occur. We expect that monitoring the water quality of the open field drains may even better reflect changes in agricultural practices. These data may also improve the understanding of contribution of agricultural nitrogen and natural nitrogen, necessary to develop measures to decrease the total-N concentration in ditch water.

  9. History and Vulnerability of Permafrost in Upland and Lowland Boreal Landscapes (Invited)

    NASA Astrophysics Data System (ADS)

    Jorgenson, M. T.; Kanevskiy, M. Z.; Shur, Y.; Harden, J. W.; O'Donnell, J.; Wickland, K. P.; Ewing, S. A.; Striegl, R. G.; Zhuang, Q.

    2010-12-01

    The history of permafrost aggradation and degradation in boreal landscapes can be interpreted through surface geomorphology, ground-ice characteristics, geochemistry, and ecological indicators. This history, which varies greatly in relation to topography, surficial materials, and ecological succession, can be simplified into four basic patterns involving rocky uplands, loamy uplands, gravelly-sandy lowlands, and peaty-loamy lowlands. In rocky uplands, permafrost conditions reflect fluctuations only over decades to century-long periods due to low latent heat of ice-poor soils and frequent fires, and history is poorly preserved. In loamy uplands with loess, water-shedding slopes, surface thermal properties, ecological recovery, and high latent heat in underlying massive ice make permafrost highly resilient. Consequently, permafrost history is well preserved as cryostructures, isotopic signatures, and buried soils. Permafrost can persist over tens to perhaps hundreds of thousands of years. In gravelly-sandy lowlands with fluvial gravels and eolian sand sheets, permafrost presence fluctuates over century periods, but because permafrost can affect surface and groundwater, changing water levels leave a legacy of plant macrofossils from aquatic and terrestrial ecosystems that can be used interpreting permafrost history. In peaty-loamy lowlands with lowland loess and abandoned floodplain deposits, water-impounding topography and permafrost-inducing soil thermal properties are conducive to permafrost fluctuations over decadal, century, and millennial periods that leave a rich legacy of plant materials indicative of specific conditions of permafrost formation and degradation. These varying responses of permafrost to environmental changes complicate the assessment of the role of permafrost in the sequestration and release of soil carbon into the atmosphere and surface waters.

  10. Geochemistry of amino acids in some Florida peat accumulations—II. Amino acid distributions

    NASA Astrophysics Data System (ADS)

    Casagrande, Daniel J.; Given, P. H.

    1980-10-01

    Distributions of amino acids in some Florida peats have been compared with distributions in plants living now at the surface of the peats and in surface litter. Quantitative determinations were made by gas chromatography of volatile derivatives of both protein and non-protein amino acids. The latter. found also in mineral soils, are believed to represent bacterial cell constituents and/or anabolites. α,ɛ-diaminopimelic acid, a constituent of the mureide complex of bacterial cell walls, was found in peats and surface litter, as were other acids believed in soil ecosystems to result from the living processes of microorganisms. The protein amino acids in peats do not show a distinctive signature of any particular kind of organism, but the nature and concentrations of the non-protein acids support the inference that the higher plant constituents are extensively re-worked and that essentially all of the amino acid material in peats is microbial in proximate origin. Thus microbial amino acids appear to be quite significant participants in the input to coalification.

  11. Genetic variation for yield and fiber quality response to supplemental irrigation within the Pee Dee Upland cotton germplasm collection

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Water availability is a major factor influencing the development of upland cotton (Gossypium hirsutum L.) cultivars and sustainable cotton production in the southeast USA because of endemic, intermittent drought events occurring in the region resulting from shallow, coarse textured soils and irregul...

  12. Impacts of peatland restoration on dissolved carbon loss from eroded upland peatlands in the UK

    NASA Astrophysics Data System (ADS)

    Evans, M.; Stimson, A.; Allott, T. E. H. A.; Holland, N.

    2012-04-01

    Upland blanket peatlands in the UK are severely degraded by extensive gully erosion. Large areas have experienced complete vegetation loss. In the last decade landscape scale approaches to the restoration of eroded and bare peat have been developed in the Peak District National Park in northern England. Bare peat is re-vegetated with a nurse crop of grasses established by the aerial application of lime, seed, and fertiliser. The approach has successfully re-vegetated large areas of eroded bog a nd has been shown to dramatically reduce particulate carbon losses in runoff. The impacts of the treatment on water quality and dissolved carbon loss have not previously been fully assessed. This paper reports results from a small catchment study assessing the impacts of restoration practice in the Peak District. Data from five small catchments are presented one re-vegetated, one intact and three eroded/bare catchments. Bi-weekly water samples have been taken from the catchments between January 2011 and February 2012 and during July 2012 two of the bare sites were treated with lime, seed, and fertiliser. The data show that there are significant spikes in nutrient flux post treatment and marked effects on dissolved carbon which include initial spikes in in DOC concentration but longer term reductions in DOC concentration. Monitoring is ongoing at these sites but the evidence to date points to at least a short term benefit in DOC flux reduction from this form of peatland restoration.

  13. Catchment-scale deposition and redistribution of Chernobyl radiocaesium in upland Britain

    SciTech Connect

    Higgitt, D.L.; Rowan, J.S. ); Walling, D.E. )

    1993-01-01

    Fallout from the Chernobyl nuclear accident in April 1986 resulted in a significant increase in the inventory of radiocaesium in many areas of upland Britain. Caesium-137 derived from nuclear weapons testing in the 1950s and 1960s has been widely used as a sediment tracer to monitor soil erosion. The presence of Chernobyl fallout provides an opportunity to examine the short-term, post-input behavior of radiocaesium in upland soils and assess its potential for investigating sediment transfer in upland systems. Sampling undertaken in the catchment of Lake Vyrnwy, North Wales considered the vertical distribution of radiocaesium in different soil types, the catchment-wide variation in Chernobyl fallout deposition, and the radiocaesium content of sediment from a variety of slope and fluvial environments. Whilst uncertainty surrounding the estimation of baseline inventories limits the detailed interpretation of short-term sediment dynamics, it is apparent that the sediment-associated redistribution of Chernobyl radioactivity may result in its accumulation in certain parts of the catchment over longer timescales. 18 refs., 6 figs., 2 tabs.

  14. Evaluating approaches for estimating peat depth

    NASA Astrophysics Data System (ADS)

    Parry, L. E.; West, L. J.; Holden, J.; Chapman, P. J.

    2014-04-01

    Estimates of peat depth are required to inform understanding of peatland development, functioning, and ecosystem services such as carbon storage. However, there is a considerable lack of peat depth data at local, national, and global scales. Recent studies have attempted to address this knowledge deficit by using manual probing and ground-penetrating radar (GPR) to estimate depth. Despite increasing application, little consideration has been given to the accuracy of either of these techniques. This study examines the accuracy of probing and GPR for measuring peat depth. Corresponding GPR and probing surveys were carried out at a catchment scale in a blanket peatland. GPR depth estimations, calibrated using common midpoint (CMP) surveys, were found to be on average 35% greater than probe measurements. The source of disagreement was found to be predominantly caused by depth probes becoming obstructed by artifacts within the peat body, although occasionally probing rods also penetrated sediments underlying the peat. Using the Complex Refractive Index Model, it was found that applying a single velocity of 0.036 m ns-1 across a single site may also result in -8 to +17% error in estimation of peat depth due to spatial variability in water content and porosity. It is suggested that GPR calibrated at each site using CMP surveys may provide a more accurate method for measuring peat depth.

  15. Characterization of peat-electrical properties by means of geoelectrical measurements

    NASA Astrophysics Data System (ADS)

    Walter, Judith; Lck, Erika; Zeitz, Jutta

    2013-04-01

    Peatlands have an important function for the storage of global carbon. These functions are reduced significantly due to intensive agricultural drainage which leads to decomposition of the organic material and hence to the loss of carbon. In order to reduce these losses, assessments of the peatlands in their current function as a carbon sink, and adequate management are required. In this context, information about both the peat thickness and their condition (degree of decomposition) are crucial. Methods which can estimate the latter in the field other than time-consuming conventional coring techniques are still missing in practice. Our approach is to gather this information in fen soils by means of non-intrusive geoelectrical techniques through the measurement of electrical conductivity of bulk soil (ECb), which is correlated with parameters such as cation exchange capacity (CEC), organic carbon (OC) and the electrical conductivity of the soil solution (ECe), which, furthermore, are functions of the peat condition. In order to assess the field-applicability of this technique, we examined as a first step the electrical properties of peat in different stages of decomposition by measuring ECb of undisturbed samples derived from various study sites in the laboratory. All parameters (ECe, CEC, OC, bulk density, pH-value and volumetric water content), which may potentially influence the ECb of peat were analyzed simultaneously. Multiple regression analysis revealed a strong response of ECb on ECe followed by CEC and water content if all samples from different locations were incorporated. ECe explained about 60%, CEC 30% and volumetric water content 10% of variability in ECb. Whereas CEC was primarily a function of the degree of decomposition of the peat, ECe levels varied from site to site and no correlation with the latter could be identified. Therefore, we assume that the estimation of peat properties, describing its condition, through electrical measurements is appropriate when considering a site specific calibration function.

  16. Evaluation of peat as a utility boiler fuel. Final report

    SciTech Connect

    Bongiorno, S.J.; Strianse, R.V.

    1983-03-01

    The objective of this study was to assess the technical and economic feasibility of the direct combustion of peat for electric power generation in the United States. The study includes a review of peat literature, selection of a region in the US to locate a hypothetical peat-harvesting operation, and an assessment of current practices for peat utilization in Europe, including peat harvesting, environmental control, and combustion technology. The conceptual design of a peat-harvesting facility supplying 1.4 million tons/yr of peat to a 2 x 150 MW power plant located in eastern North Carolina is developed for the purpose of estimating peat fuel costs. Environmental-control measures and peat transportation systems are identified. Budget capital and operating costs for a peat-fired power plant are estimated and the busbar cost of electricity compared to that for a 1 x 300 MW coal-fired power plant. Technical feasibility is demonstrated, although environmental acceptability of a large-scale peat harvesting operation must be confirmed on a site-specific basis. Peat fuel costs are found to be less than coal costs for a power plant located adjacent to the peat bogs in eastern North Carolina. The higher capital cost of a peat-fired power plant offsets to some extent the fuel cost advantage. Peat is found to have an electricity cost advantage of about 5 to 25% when compared to coal on a 30 year levelized basis depending on the peat escalation rate assumed.

  17. HYDRAULIC CONDUCTIVITY OF ESSENTIALLY SATURATED PEAT

    SciTech Connect

    Nichols, R

    2008-02-27

    The Savannah River National Laboratory measured the hydraulic conductivity of peat samples using method ASTM D4511-00. Four samples of peat were packed into 73mm diameter plastic tubes and saturated from the bottom up with water. The columns were packed with Premier ProMoss III TBK peat to a dry density of approximately 0.16 gm/cc (10 lb/ft3). One column was packed using oven dried peat and the other 3 were packed using as delivered peat. The oven dried sample was the most difficult to saturate. All of the peat samples expanded during saturation resulting in a sample length (L) that was longer than when the sample was initially packed. Table 1 contains information related to the column packing. After saturation the hydraulic conductivity test was conducted using the apparatus shown in Figure 1. Three of the samples were tested at 2 different flow conductions, 1 high and 1 low. Table 2 and Figure 2 contain the results of the hydraulic conductivity testing. Each test was run for a minimum of 40 minutes to allow the test conditions to stabilize. The hydraulic conductivity at the end of each test is reported as the hydraulic conductivity for that test. The hydraulic conductivity of the 4 peat samples is 0.0052 {+-} 0.0009 cm/sec. This result compares well with the hydraulic conductivity measured in the pilot scale peat bed after approximately 2 months of operation. The similarity in results between the dry pack sample and moist pack samples shows the moisture content at the time of packing had a minimal effect on the hydraulic conductivity. Additionally, similarity between the results shows the test is reproducible. The hydraulic conductivity results are similar to those reported by other tests of peat samples reported in the literature.

  18. How old is upland catchment water?

    NASA Astrophysics Data System (ADS)

    Hofmann, Harald; Cartwright, Ian; Morgenstern, Uwe; Gilfedder, Benjamin

    2014-05-01

    Understanding the dynamics of water supply catchments is an essential part of water management. Upland catchments provide a continuous, reliable source of high quality water not only for some of the world's biggest cities, but also for agriculture and industry. Headwater streams control river flow in lowland agricultural basins as the majority of river discharge emerges from upland catchments. Many rivers are perennial and flow throughout the year, even during droughts. However, it is still unclear how reliable and continuous upland catchment water resources really are. Despite many efforts in upland catchment research, there is still little known about where the water is stored and how long it takes to travel through upper catchments. Resolving these questions is crucial to ensure that this resource is protected from changing land use and to estimate potential impacts from a changing climate. Previous research in this important area has been limited by existing measurement techniques. Knowledge to date has relied heavily on the use of variation in stable isotope signals to estimate the age and origin of water from upland catchments. The problem with relying on these measures is that as the water residence time increases, the variation in the stable isotope signal decreases. After a maximum period of four years, no variation can be detected This means that to date, the residence time in upland catchments is likely to have been vastly underestimated. Consequently, the proportion of water flow out of upland river catchments to the total river flow is also underestimated. Tritium (3H) combines directly with water molecules and enters the flow paths with the infiltrating water. Its half-life (12.32 years) makes it ideal to describe residence times in upper catchment reservoirs as it can theoretically measure water up to about 150 years old. The bomb pulse peak in the southern hemisphere was several orders of magnitude lower than in the northern hemisphere. Hence the Tritium activities in the southern hemisphere have long decayed down the natural background levels, which allows unique ages to be determined by single measurements. In this study major ion chemistry, stable isotopes and Tritium were determined at 2 locations and various stages of discharge (18 Tritium samples in between April 2013 and January 2014) in a first-order perennial stream draining a 7.3 km2 catchment in the Dandenong National Park, Melbourne, Australia. Even during major discharge event major ions and stable isotope data have little variation and Tritium activities remain low (1.4 to 1.8 TU) in comparison to local rainfall of ~ 3TU. Age estimations based on an exponential flow model are 15 to 25 years indicating that water draining from upland catchments is much older than we have previously estimated using stable isotopes.

  19. Minerals yearbook, 1993: Peat. Annual report

    SciTech Connect

    Bolen, W.P.

    1994-11-01

    The U.S. Bureau of Mines (USBM) annual survey of domestic peat producers in the 48 contiguous United States reflected a 3% increase in production accompanied by the closure of two U.S. peat operations in the States of Maine and Michigan and the first full year of operations at a new Minnesota peat mine. Sales volume fell 6% to just more than 0.6 million tons, although the total value of producer sales increased slightly to $16.8 million, f.o.b. plant. Idled and discontinued operations continued to liquidate stocks.

  20. Trace element content of northern Ontario peat

    SciTech Connect

    Glooschenko, W.A.; Capoblanco, J.A.

    1982-03-01

    Peat samples were collected at 0-20- and 20-40-cm depths from several peatland ecosystems located in northern Ontario, Canada. Analysis was made for the trace metals Zn, Pb, Cu, Cr, Cd, and Hg. Concentration values in general were in the low ppm range and did not significantly differ in terms of peatland type or depth except for Pb. This element was signficantly higher in surface peats in bogs and fens. Concentration of metals in peats found in the study were equivalent to those in US coals, suggesting caution during combustion in terms of potential atmospheric input of metals.

  1. Peat humic acids and their complex forming properties as influenced by peat humification

    NASA Astrophysics Data System (ADS)

    Dudare, D.; Klavins, M.

    2012-04-01

    To study paleoenvironmental changes of importance is understanding of processes of organic matter diagenesis, especially changes of refractory part of natural organic substances - humic substances. Studies of the living organic matter humification process are also essential for understanding of the carbon biogeochemical cycle. The aim of this study was to analyze peat organic matter diagenesis: changes of properties of humic acids, relations between the humification process, properties of peat, peat humic acids, their ability to interact with metal ions, as well ability to accumulate metals. The analysis were carried out on samples of humic substances preparatively extracted from three ombrotrophic bog peat profiles to identify the links between peat age, decomposition and humification degree, botanical composition and properties of peat humic acids elemental (C, H, N, O), functional (-COOH, -OH) composition, structural characteristics - UV, fluorescence, FTIR. The found variability of peat properties is less significant than differences in the properties of peat-forming living matter, thus revealing the dominant impact of humification process on the properties of peat. Correspondingly, composition of peat humic acids is little affected by differences in the properties of precursor living organic material, and such indicators as decomposition degree, humification degree, humic acid elemental ratio and concentrations of acidic functional groups are the best descriptors of changes in organic matter during the process of organic matter diagenesis and humification. Peat ability to accumulate major and trace elements depends on the character of element supply, potency of metal ions to bind functionalities in the peat, with an emphasis on the structure of peat humic acid, pH reaction, oxygen presence, presence of complexing compounds, inorganic ions and many other factors. Major and trace element presence in peat is of importance as an indicator of peat genesis and organic matter humification processes. We studied accumulation of trace element in peat profile to reconstruct the changes of human pollution and track down sources and characterize intensity of anthropogenic pollution. In view of this, the major and trace element distribution between peat and peat humic acids from three well characterized raised bog profiles was assigned and factors affecting element concentrations in peat humic acids were analysed. Complex forming properties of isolated humic acids were studied as well and compared with structural features of peat humic acids, also were compared with reference and synthetic humic substances. The Cu(II) complexing capacity and stability constants of Cu(II) complexes of peat humic acids were determined in respect to the basic properties and humification characteristics of the studied peats and their humic acids. Stability constants significantly changed within studied bog profiles, also well correlated with age and decomposition degree of peat layer from which humic acids were isolated. Keywords: humic substances, peat, complexing capacity, stability constant, humic acids, humification

  2. Interdependence of peat and vegetation in a tropical peat swamp forest.

    PubMed

    Page, S E; Rieley, J O; Shotyk, W; Weiss, D

    1999-11-29

    The visual uniformity of tropical peat swamp forest masks the considerable variation in forest structure that has evolved in response to differences and changes in peat characteristics over many millennia. Details are presented of forest structure and tree composition of the principal peat swamp forest types in the upper catchment of Sungai Sebangau, Central Kalimantan, Indonesia, in relation to thickness and hydrology of the peat. Consideration is given to data on peat geochemistry and age of peat that provide evidence of the ombrotrophic nature of this vast peatland and its mode of formation. The future sustainability of this ecosystem is predicted from information available on climate change and human impact in this region. PMID:11605630

  3. Upland disturbance affects headwater stream nutrients and suspended sediments during baseflow and stormflow

    SciTech Connect

    Houser, Jeffrey N

    2006-01-01

    Because catchment characteristics determine sediment and nutrient inputs to streams, upland disturbance can affect stream chemistry. Catchments at the Fort Benning Military Installation (near Columbus, Georgia) experience a range of upland disturbance intensities due to spatial variability in the intensity of military training. We used this disturbance gradient to investigate the effects of upland soil and vegetation disturbance on stream chemistry. During baseflow, mean total suspended sediment (TSS) concentration and mean inorganic suspended sediment (ISS) concentration increased with catchment disturbance intensity (TSS: R 2 = 0.7, p = 0.005, range = 4.0-10.1 mg L-1; ISS: R 2 = 0.71, p = 0.004, range = 2.04-7.3 mg L-1); dissolved organic carbon (DOC) concentration (R 2 = 0.79, p = 0.001, range = 1.5-4.1 mg L-1) and soluble reactive phosphorus (SRP) concentration (R 2 = 0.75, p = 0.008, range = 1.9-6.2 {micro}g L-1) decreased with increasing disturbance intensity; and ammonia (NH4 +), nitrate (NO3 -), and dissolved inorganic nitrogen (DIN) concentrations were unrelated to disturbance intensity. The increase in TSS and ISS during storms was positively correlated with disturbance (R 2 = 0.78 and 0.78, p = 0.01 and 0.01, respectively); mean maximum change in SRP during storms increased with disturbance (r = 0.7, p = 0.04); and mean maximum change in NO3 - during storms was marginally correlated with disturbance (r = 0.58, p = 0.06). Soil characteristics were significant predictors of baseflow DOC, SRP, and Ca2+, but were not correlated with suspended sediment fractions, any nitrogen species, or pH. Despite the largely intact riparian zones of these headwater streams, upland soil and vegetation disturbances had clear effects on stream chemistry during baseflow and stormflow conditions.

  4. Effects of upland disturbance and instream restoration on hydrodynamics and ammonium uptake in headwater streams

    USGS Publications Warehouse

    Roberts, B.J.; Mulholland, P.J.; Houser, J.N.

    2007-01-01

    Delivery of water, sediments, nutrients, and organic matter to stream ecosystems is strongly influenced by the catchment of the stream and can be altered greatly by upland soil and vegetation disturbance. At the Fort Benning Military Installation (near Columbus, Georgia), spatial variability in intensity of military training results in a wide range of intensities of upland disturbance in stream catchments. A set of 8 streams in catchments spanning this upland disturbance gradient was selected for investigation of the impact of disturbance intensity on hydrodynamics and nutrient uptake. The size of transient storage zones and rates of NH4+ uptake in all study streams were among the lowest reported in the literature. Upland disturbance did not appear to influence stream hydrodynamics strongly, but it caused significant decreases in instream nutrient uptake. In October 2003, coarse woody debris (CWD) was added to 1/2 of the study streams (spanning the disturbance gradient) in an attempt to increase hydrodynamic and structural complexity, with the goals of enhancing biotic habitat and increasing nutrient uptake rates. CWD additions had positive short-term (within 1 mo) effects on hydrodynamic complexity (water velocity decreased and transient storage zone cross-sectional area, relative size of the transient storage zone, fraction of the median travel time attributable to transient storage over a standardized length of 200 m, and the hydraulic retention factor increased) and nutrient uptake (NH4+ uptake rates increased). Our results suggest that water quality in streams with intense upland disturbances can be improved by enhancing instream biotic nutrient uptake capacity through measures such as restoring stream CWD. ?? 2007 by The North American Benthological Society.

  5. Influence of peat formation conditions on the transformation of peat deposit organic matter

    NASA Astrophysics Data System (ADS)

    Serebrennikova, O. V.; Strelnikova, E. B.; Preis, Yu I.; Duchko, M. A.

    2015-11-01

    The paper studies the individual composition of n-alkanes, polycycloaromatic hydrocarbons, steroids, bi-, tri-, and pentacyclic terpenoids of two peat deposits of rich fen Kirek located in Western Siberia. Considering the individual n-alkanes concentrations, some indexes were calculated to estimate the humidity during peat formation. It was shown that the pH of peat medium primarily affects steroids, tri- and pentacyclic terpenoids transformations.

  6. Impact of biochar on nitrous oxide emissions from upland rice.

    PubMed

    Petter, Fabiano André; Borges de Lima, Larissa; Marimon Júnior, Ben Hur; Alves de Morais, Leidimar; Marimon, Beatriz Schwantes

    2016-03-15

    The objective of this research was to assess the emission of nitrous oxide (N2O) from soil amended with biochar in the culture of upland rice. The experiment was conducted in the field in a Cerrado Haplic Plinthosol under randomized block experimental design. The treatments consisted of fertilization with 100 kg N ha(-1) split into two applications, 60% at sowing and 40% at 45 days after crop emergence, combined with four doses of biochar (0, 8, 16 and 32 Mg ha(-1)), with four replications. The application of N and the emission of N2O, moisture retention and soil temperature, respiration (C-CO2), microbial biomass carbon in the soil (C-SMB), total nitrogen (TN), pH and agronomic efficiency in N use (AENu) were evaluated five years after the application of biochar. There was a significant correlation of the application of biochar with moisture retention (r = 0.94**), N2O emission (r = 0.86**) and soil pH (r = 0.65*), and N2O emissions showed a positive correlation (p < 0.05) with soil moisture (r = 0.77**) and pH (r = 0.66*). Thus the highest N2O emissions were observed shortly after N fertilization and in the treatments with 32 Mg ha(-1) of biochar. Despite the higher N2O emissions from the application of 32 Mg ha(-1) of biochar, the emission factor was lower (0.81%) than the maximum recommended by the IPCC. The higher N2O emissions with application of biochar are offset by more efficient use of N and consequently the possibility of reduction of applied doses. PMID:26716573

  7. 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. PMID:23526779

  8. Hydraulic Conductivity of Riparian Mangrove Forest Peat Adjacent to the Harney River, Everglades National Park: A Comparative Field Study of Field Saturated and Saturated Hydraulic Conductivity Methods.

    NASA Astrophysics Data System (ADS)

    Anderson, G. H.; Smith, T. J.

    2002-05-01

    The Shark-Harney river estuary is located in the southwest region of Everglades National Park and is the principle outflow for the freshwater everglades slough. Periodic tidal inundation, rainfall and overland freshwater flow are the forcing functions on surface soil infiltration and drainage in the adjacent estuary mangrove forest peat. Empirical soil hydraulic conductivity (K) for the mangrove peat soil is needed for hydrologic modeling efforts such as "The Tides and Inflows in the Mangroves of the Everglades" (TIME). South Florida has a bi-seasonal weather pattern of a dry and mild winters and a wet tropical summers. During the drier winter months (November-May), the mangrove peat has a 30-60 cm, unsaturated vadose zone and in the wet summer months (June-October), the peat is totally saturated. This study's purpose is to determine reliable values of soil hydraulic conductivity for mangrove peat under both the unsaturated Kfs and saturated Ksat soil conditions. Rycroft (1975) reported that field measurements are the preferred method of testing hydraulic conductivity of peat. The principle field method used to determining soil hydraulic conductivity Kfs under unsaturated conditions utilized a cylindrical permeameter (Guelph Permeameter) and the auger-hole method was used to determine soil hydraulic conductivity Ksat under saturated soil conditions. The hydraulic conductivity K samples were taken along a 300-meter transect, perpendicular to the south Harney riverbank through a mixed mangrove riparian forest and ending in a freshwater sawgrass prairie. Initial measurements were recorded in May-June 2001. A second year measurement set will be collected in March-April 2002. Hydraulic conductivity K measurements were observed in shallow peat holes (15 cm) at five equally spaced sample sites (60 m) from the river edge. Soil cores were taken at each sampling site to determine soil profile and bulk density.

  9. Upland forests of the American/Pacific islands: Research opportunities in Micronesia and American Samoa. Forest Service general technical report (Final)

    SciTech Connect

    DeBell, D.S.; Whitesell, C.D.

    1993-07-01

    The Upland forests of Micronesia and American Samoa can provide many social, ecological, and esthetic benefits for island inhabitants. Substantial upland areas (the majority of acreage on some islands) are now occupied by secondary and grassland/savanna vegetation: such areas represent opportunities for restoration, with both native forest cover and plantations of introduced species. The review briefly describes characteristics of the islands and the nature of existing and potential upland forests, including the most common upland tree species. Principal information needs and research opportunities are discussed for 10 subjects: watershed rehabilitation, forest restoration in secondary vegetation areas, basic ecology, soils and nutrient relationships, damaging agents, forest inventory and productivity assessment, silvicultural systems, valuation of forest products and services, threatened and endangered species, and description and protection of native forest habitats.

  10. Radioactivity of peat mud used in therapy.

    PubMed

    Karpi?ska, Maria; Mnich, Krystian; Kapa?a, Jacek; Bielawska, Agnieszka; Kulesza, Grzegorz; Mnich, Stanis?aw

    2016-02-01

    The aim of the study was to determine the contents of natural and artificial isotopes in peat mud and to estimate the radiation dose absorbed via skin in patients during standard peat mud treatment. The analysis included 37 samples collected from 8 spas in Poland. The measurements of isotope concentration activity were conducted with the use of gamma spectrometry methods. The skin dose in a standard peat mud bath therapy is approximately 300nSv. The effective dose of such therapy is considered to be 22nSv. The doses absorbed during peat mud therapy are 5 orders of magnitude lower than effective annual dose absorbed from the natural radiation background by a statistical Pole (3.5mSv). Neither therapeutic nor harmful effect is probable in case of such a small dose of ionising radiation. PMID:26675542

  11. Investigation of gas exchange processes in peat bog ecosystems by means of innovative Raman gas spectroscopy.

    PubMed

    Frosch, Torsten; Keiner, Robert; Michalzik, Beate; Fischer, Bernhard; Popp, Jürgen

    2013-02-01

    Highly sensitive Raman gas spectroscopy is introduced for simultaneous real time analysis of O(2), CO(2), CH(4), and N(2) in order to elucidate the dynamics of greenhouse gases evolving from climate-sensitive ecosystems. The concentrations and fluxes of this suite of biogenic gases were quantified in the head space of a water-saturated, raised peat bog ecotron. The intact peat bog, exhibiting various degradation stages of peat and sphagnum moss, was exposed to various light regimes in order to determine important ecosystem parameters such as the maximum photosynthesis rate of the sphagnum as well as the extent of soil and plant respiration. Miniaturized Raman gas spectroscopy was proven to be an extremely versatile analytical technique that allows for onsite multigas analysis in high temporal resolution. Therefore it is an urgently needed tool for elucidation of complex biochemical processes especially in climate-sensitive ecosystems and consequently for the estimation of climate-relevant gas budgets. PMID:23320649

  12. Measurement and modeling of soil-water dynamics and evapotranspiration of drained peatland soils

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Natural peat soils serve as important sinks for nutrients, organic components, and water. Peat soils can pose major environmental problems when they are drained for agricultural production, which may change their role in the landscape from a sink to a source. To successfully restore and conserve pea...

  13. A Few Issues on the Peat Research in the Altai Mountains

    NASA Astrophysics Data System (ADS)

    Inisheva, Lydia I.; Larina, Galina; Shurova, Maya

    2010-05-01

    At the present time we carry out complex research of marsh ecosystems in various areas of Gorny Altai to reveal the perspective deposits of peat in the Altai Mountains with the purpose of its use in the medical and recreational spheres. The peat deposits of the Northeastern Altai, Central Altai, and Southeastern Altai are surveyed; the selective chemical analysis of peat and marsh waters is carried out. The group structure of organic substance of various samples of peat is investigated by the method of Institutes of Peat. The toxic metals of Cd, Pb, Hg, Cu, Zn, and As were defined by the method of stripping voltammetry. The region of the Altai Mountains is characterized by the contrastive distribution of some heavy metals and arsenic in a soil cover. This is caused by a variety of petrography and granulometry of soil forming material, and also by a landscape and geochemical situation in the system of vertical zoning. The sources of natural accumulation of heavy metals in the ground might be the deposits of polymetals. In this connection the content of the specified toxic elements in the peat under research has been identified. The peat of the Turochak deposit is characterized by a significant ash content - up to 41,9%; the increased ash content is typical of the Kutyush deposit: from 6,1% up to 19, %. The peat of the Northeastern Altai is referred to non-bitumunous: the content of bitumen makes up less than 5%. In comparison with the European peat the peat under study of the transitive and lowland type is characterized by the significant content of easy hydrolysable substances in the amount of 24,8-41,1%. The amount of the non-hydrolysable rest makes up around 4,3 - 7,4 %. The total content of fulvic acids is less than the content of humic acids by 2,9 - 5,8 times. The high content of humic acids which can reach up to 58 % is characteristic of certain deposits. Humic acids extracted from the peat are characterized, as a rule, by similar IR-spectra. The distinctions are shown in an unequal intensity of characteristic absorption bands, in their spreading and some shifts. It is revealed that humic acids of peat with the increase in a degree of decomposition are exposed to transformation; therefore the increase in their structure of functional groups is observed. As a result of the research which was carried out the following elements among heavy metals in the lowland peat of the Altai Mountains are revealed: Cd (2,7 - 30)> Hg (0,67)> Zn (0,22) ~Pb (0,21)> Cu (0,13)> As (0,03). The degree of mobility of chemical elements in the peat varies within the limits of 1,3 - 36%. According to the degree of their mobility these elements form the following line: Zn (36 %)> Pb (18,1 %)> Cd (9,6 %)> Cu (1,3 %). The content and the character of distribution of the heavy metals under study and arsenic in the peat of the Altai Mountains have their unique features in comparison with the same valley analogues. The mountain peat of the Central Altai contains much less Hg than the West Siberian one: 0,078 mg/g and 0,69 mg/g accordingly. Cd represents itself as the concentrator in the lowland peat of the Northeastern and Central Altai, its content is actually the same and makes up approximately 0,3 mg/kg. The lowland Altai and West Siberian peat has the same amount of Pb: 4-5 mg/kg; they have smaller amounts of Zn and Cu in comparison with the European and West Siberian peat. The revealed features of distribution of some toxic metals are the display of specificity of peat genesis in the conditions of a mountain relief. The complex of the data received by us allows to consider the peat of the Altai Mountains as a non-polluting raw source concerning the amount of some natural toxic substances. The possible perspective directions of practical application of the mountain peat can be medicine, veterinary science, and agriculture.

  14. Peat accumulation in drained thermokarst lake basins in continuous, ice-rich permafrost, northern Seward Peninsula, Alaska

    NASA Astrophysics Data System (ADS)

    Jones, Miriam C.; Grosse, Guido; Jones, Benjamin M.; Walter Anthony, Katey

    2012-06-01

    Thermokarst lakes and peat-accumulating drained lake basins cover a substantial portion of Arctic lowland landscapes, yet the role of thermokarst lake drainage and ensuing peat formation in landscape-scale carbon (C) budgets remains understudied. Here we use measurements of terrestrial peat thickness, bulk density, organic matter content, and basal radiocarbon age from permafrost cores, soil pits, and exposures in vegetated, drained lake basins to characterize regional lake drainage chronology, C accumulation rates, and the role of thermokarst-lake cycling in carbon dynamics throughout the Holocene on the northern Seward Peninsula, Alaska. Most detectable lake drainage events occurred within the last 4,000 years with the highest drainage frequency during the medieval climate anomaly. Peat accumulation rates were highest in young (50-500 years) drained lake basins (35.2 g C m-2 yr-1) and decreased exponentially with time since drainage to 9 g C m-2 yr-1 in the oldest basins. Spatial analyses of terrestrial peat depth, basal peat radiocarbon ages, basin geomorphology, and satellite-derived land surface properties (Normalized Difference Vegetation Index (NDVI); Minimum Noise Fraction (MNF)) from Landsat satellite data revealed significant relationships between peat thickness and mean basin NDVI or MNF. By upscaling observed relationships, we infer that drained thermokarst lake basins, covering 391 km2 (76%) of the 515 km2 study region, store 6.4-6.6 Tg organic C in drained lake basin terrestrial peat. Peat accumulation in drained lake basins likely serves to offset greenhouse gas release from thermokarst-impacted landscapes and should be incorporated in landscape-scale C budgets.

  15. Peat accumulation in drained thermokarst lake basins in continuous, ice-rich permafrost, northern Seward Peninsula, Alaska

    USGS Publications Warehouse

    Jones, Miriam C.; Grosse, Guido; Jones, Benjamin M.; Anthony, Katey Walter

    2012-01-01

    Thermokarst lakes and peat-accumulating drained lake basins cover a substantial portion of Arctic lowland landscapes, yet the role of thermokarst lake drainage and ensuing peat formation in landscape-scale carbon (C) budgets remains understudied. Here we use measurements of terrestrial peat thickness, bulk density, organic matter content, and basal radiocarbon age from permafrost cores, soil pits, and exposures in vegetated, drained lake basins to characterize regional lake drainage chronology, C accumulation rates, and the role of thermokarst-lake cycling in carbon dynamics throughout the Holocene on the northern Seward Peninsula, Alaska. Most detectable lake drainage events occurred within the last 4,000 years with the highest drainage frequency during the medieval climate anomaly. Peat accumulation rates were highest in young (50–500 years) drained lake basins (35.2 g C m−2 yr−1) and decreased exponentially with time since drainage to 9 g C m−2 yr−1 in the oldest basins. Spatial analyses of terrestrial peat depth, basal peat radiocarbon ages, basin geomorphology, and satellite-derived land surface properties (Normalized Difference Vegetation Index (NDVI); Minimum Noise Fraction (MNF)) from Landsat satellite data revealed significant relationships between peat thickness and mean basin NDVI or MNF. By upscaling observed relationships, we infer that drained thermokarst lake basins, covering 391 km2 (76%) of the 515 km2 study region, store 6.4–6.6 Tg organic C in drained lake basin terrestrial peat. Peat accumulation in drained lake basins likely serves to offset greenhouse gas release from thermokarst-impacted landscapes and should be incorporated in landscape-scale C budgets.

  16. Peat archives from Siberia: Synchrotron beam scanning with X-ray fluorescence measurements

    NASA Astrophysics Data System (ADS)

    Phedorin, M. A.; Bobrov, V. A.; Zolotarev, K. V.

    2007-05-01

    We used a new approach to measure the downcore distribution of some major and trace elements that record the Holocene history of peat-forming processes in peat from the Elovka mesotrophic swamp (West Siberia). The approach implies continuous non-destructive scanning of natural wet-core fragments under a sharp synchrotron beam combined with measurements of the excited X-ray fluorescence, in attempt to avoid errors due to the loss of volatiles abundant in peat. The obtained data are in good agreement with the results of the certified methods of neutron activation gamma-spectrometry (INAA) and classical SR XRF, though, as we expected, there is some discrepancy in the contents of volatiles (Br, Zn) which are most probably lost in INAA and/or in ignition. The precision of the suggested SR XRF scanning resolved the variability of 18 elements in the peat-core deposited during 0-8 kyr bp at no worse than 30 years in most cases. The distribution of the measured elements provided a clue to the evolution of peat deposition environments that controlled biogenic production, aerosol input, post-depositional processes, and Ca mineralization associated with pore water circulation in soil during the non-mesotrophic stages of the swamp history.

  17. Development of new peat based growing media by addition of pruning waste and biochars

    NASA Astrophysics Data System (ADS)

    Nieto, Aurora; Gascó, Gabriel; Paz-Ferreiro, Jorge; Plaza, César; Fernández, José Manuel; Méndez, Ana

    2015-04-01

    In the last years, several researches have been performed to find high quality and low cost substrates from different organic wastes in order to decrease peat consumption since the indiscriminate exploitation of peat lands is exhausting this non-renewable useful resource and destroying endangered wetland ecosystems worldwide. The use of organic wastes as soil amendments or possible peat substitute could be improved by pyrolysis treatment, leading to biochar, a carbon-rich material that has attached important attention. Our research group has been worked in the formulation of new based-growing media by peat substitution in 50 and 75 vol% of pruning waste (PW), commercial charcoal (CC), biochar from PW at 300°C (B300) and 500°C (B500). Growing media show adequate physicochemical and hydrophysical properties. Experiments performed with lettuce germination show that PW addition in a 75vol% reduces germination index probably due to their high content on phenolic compounds. Lettuce growing experiments were performed during 5 weeks and show that addition of PW and CC to peat decreases biomass production whereas; B300 and specially, B500 addition significantly increases the lettuce biomass.

  18. Hyperspectral data application for peat forest monitoring in Central Kalimantan, Indonesia

    NASA Astrophysics Data System (ADS)

    Ohki, Takashi; Yoshida, Keigo; Sekine, Hozuma; Takayama, Taichi; Takeda, Tomomi; Hirose, Kazuyo; Evri, Muhammad; Osaki, Mitsuru

    2012-11-01

    Peatland is a large CO2 reservoir which accumulates 2000Gt of CO2, which is equal to 30% of global soil carbon. However, it has been becoming a large CO2 emission source because of peat decomposition and fire due to drainage water. This is caused by social activities such as canalizing. Especially, in Indonesia, peat swamp forests cover considerable portions of Kalimantan and 37.5% of CO2 emission source is peatland (DNPI, 2010). To take measures, it is necessary to conduct appropriate assessment of CO2 emission in broad peat swamp forest. Because hyperspectral data possess higher spectral resolutions, it is expected to evaluate the detailed forest conditions. We develop a method to assess carbon emission from peat swamp forest by using hyperspectral data in Central Kalimantan, Indonesia. Specifically, we estimate 1) forestry biomass and 2) underground water level expected as an indicator of CO2 emission from peat. In this research, we use the image taken by HyMAP which is one of the airborne hyperspectral sensors. Since the research area differs in forest types and conditions due to the past forest fire and disturbance, forest types are classified with the sparse linear discriminant analysis. Then, we conduct a biomass estimation using Normalized Difference Spectral Index (NDSI). We also analyze the relationship between underground water level and Normalized Difference Water Index (NDWI), and find the possibility of underground water level estimation with hyperspectral data. We plan to establish a highly developed method to apply hyperspectral sensor to peatland monitoring system.

  19. Effect of biogenic gas bubbles on water flow through poorly decomposed blanket peat

    NASA Astrophysics Data System (ADS)

    Beckwith, Clive W.; Baird, Andrew J.

    2001-03-01

    A laboratory investigation was used to determine whether biogenic gas bubbles accumulate and block water-conducting pores below the water table in poorly decomposed Sphagnum peat. We found that biogenic gas bubbles did accumulate under realistic incubation temperatures. At the end of incubations at 10.5C, volumetric water contents in two peat samples decreased to between 0.8 and 0.85 (porosity of the samples ranged from 0.96 to 0.97), indicating that the peat was considerably undersaturated with respect to water. Methane was found to be an important constituent of the gas bubbles. The presence of gas bubbles appeared to have a major effect on hydraulic conductivity (K). In control incubations, prior to which the peat had been irradiated and dosed with a biocide, biogenic gas bubbles did not accumulate, and K was 5-8 times higher than at the end of the microbially active incubations. Our results suggest that biogenic gas bubbles have a potentially significant effect on seepage in peat soils.

  20. The role of fungi in the Sphagnum peat wastewater treatment system

    SciTech Connect

    Brooks, J.L.

    1988-01-01

    The lack of suitable soils and the increased building in rural areas has led to the need for alternative onsite wastewater treatment systems. One alternative system utilizes Sphagnum peat to provide a high quality effluent (<10 mg/l BOD5, <6 mg/l nitrate N, and <1 fecal coliform bacteria/100 ml). Treatment efficiencies were greatest when the temperature of the peat was 0-10{degree}C. During this period the organic N and ammonia-N concentrations in the septic tank effluent were reduced by 90-95% and 95-99% respectively; the effluent contained 0.4-1.4 mg/liter organic N and 0.2-1.9 mg/liter ammonia-N. Treatment of the septic tank effluent is attributed to physical filtration, adsorption, and microbiological activity. Microbiological treatment of wastewater has traditionally been attributed to bacteria; however, the cool, acidic, aerobic environment in the peat system favored the growth and activity of fungi over that of bacteria. The fungal population recovered from the system by plating techniques ranged from 1.9 {times} 10{sup 6} to 1.2 {times} 10{sup 9} colony forming units/gram of dry peat. Additional yeast species and zoosporic fungi were recovered from the peat samples by shake-culturing and baiting techniques. The ratio of fungal to bacterial activity, as measured by relative respiration rates, was 8:1 in the winter months and 6:2.5 in the summer. Excessive growth of fungi was controlled by the enchytraeid-worm population which was, in turn, fed upon by skunks, racoons, and birds. Additional nutrients were removed from the system when surface vegetation was harvested. Peat wastewater treatment systems, when properly designed and constructed, may be used effectively on adverse sites; their documented lifespan is ten years and their projected lifespan equals that of conventional soil adsorption systems.

  1. Mass tree mortality leads to mangrove peat collapse at Bay Islands, Honduras after Hurricane Mitch

    USGS Publications Warehouse

    Cahoon, D.R.; Hensel, P.; Rybczyk, J.; McKee, K.L.; Proffitt, C.E.; Perez, B.C.

    2003-01-01

    We measured sediment elevation and accretion dynamics in mangrove forests on the islands of Guanaja and Roatan, Honduras, impacted by Hurricane Mitch in 1998 to determine if collapse of underlying peat was occurring as a result of mass tree mortality. Little is known about the balance between production and decomposition of soil organic matter in the maintenance of sediment elevation of mangrove forests with biogenic soils. Sediment elevation change measured with the rod surface elevation table from 18 months to 33 months after the storm differed significantly among low, medium and high wind impact sites. Mangrove forests suffering minimal to partial mortality gained elevation at a rate (5 mm yeara??1) greater than vertical accretion (2 mm yeara??1) measured from artificial soil marker horizons, suggesting that root production contributed to sediment elevation. Basin forests that suffered mass tree mortality experienced peat collapse of about 11 mm yeara??1 as a result of decomposition of dead root material and sediment compaction. Low soil shear strength and lack of root growth accompanied elevation decreases. Model simulations using the Relative Elevation Model indicate that peat collapse in the high impact basin mangrove forest would be 37 mm yeara??1 for the 2 years immediately after the storm, as root material decomposed. In the absence of renewed root growth, the model predicts that peat collapse will continue for at least 8 more years at a rate (7 mm yeara??1) similar to that measured (11 mm yeara??1). Mass tree mortality caused rapid elevation loss. Few trees survived and recovery of the high impact forest will thus depend primarily on seedling recruitment. Because seedling establishment is controlled in large part by sediment elevation in relation to tide height, continued peat collapse could further impair recovery rates.

  2. Drainage and land use impacts on changes in selected peat properties and peat degradation in West Kalimantan Province, Indonesia

    NASA Astrophysics Data System (ADS)

    Anshari, G. Z.; Afifudin, M.; Nuriman, M.; Gusmayanti, E.; Arianie, L.; Susana, R.; Nusantara, R. W.; Sugardjito, J.; Rafiastanto, A.

    2010-11-01

    Degradation of tropical peats is a global concern due to large Carbon emission and loss of biodiversity. The degradation of tropical peats usually starts when the government drains and clears peat forests into open peats used for food crops, oil palm and industrial timber plantations. Major properties of tropical peat forests are high in Water Contents (WC), Loss on Ignition (LOI) and Total Organic Carbon (TOC), and low in peat pH, Dry Bulk Density (DBD), and Total Nitrogen (TN). In this study, we investigated impacts of drainage and land use change on these properties. We collected peat samples from peat forests, logged over peat forest, industrial timber plantation, community agriculture, and oil palms. We used independent t-tests and oneway ANOVA to analyze mean differences of the research variables. We found that peat pH, DBD, and TN tend to increase. A significant decrease of C/N ratio in oil palm and agriculture sites importantly denotes a high rate of peat decompositions. Water contents, LOI, and TOC are relatively constants. We suggest that changes in pH, DBD, TN and atomic C/N ratio are important indicators for assessing tropical peat degradation. We infer that land use change from tropical peat forests into cleared and drained peats used for intensive timber harvesting, oil palms and industrial timber plantations in Indonesia has greatly degraded major ecological function of tropical peats as Carbon storage.

  3. A comparison between conventional and AMS [sup 14]C dates on basal salt marsh peats from coastal Maine. [Accelerator Mass Spectroscopy

    SciTech Connect

    Gehrels, R.W.; Belknap, D.F. . Dept. of Geological Sciences)

    1992-01-01

    This study reports AMS dates from four Maine salt marshes: Webbannet Marsh (Wells), Morse and Sprague River marshes (Phippsburg), and Sanborn Cove marsh (Machiasport). The AMS dates are compared with conventional dates on bulk samples obtained from either the same cores or from other cores at comparable depths. Four AMS dates from the Webhannet and Sanborn Cove marshes were considerably older than their conventional counterparts, by as much as 1,000 years. Three causes for this age discrepancy are suggested. First, under slow rates of marsh accretion, peats remain within the root zone of modern plants for a relatively long period, causing a continued input of younger carbon. Intruded roots are undetectable in the highly macerated, 4,000--5,000 C-14 year old peats. Another source of contamination is the percolation of mobile humic acids along the impermeable Pleistocene substrate. Finally, a date on a bulk peat of 10 cm vertical extent represents an average age for a portion of peat that spans a time interval possibly of several centuries. The age difference between the bulk date and the AMS date from the base of the peat increases with decreasing rates of marsh accretion. The forested steep slopes of the upland surrounding the marsh seem a likely source of old carbon that can easily be washed onto the marsh surface. The slow rate of late-Holocene sea-level rise in Maine, as well as the geologic and hydrologic setting of the salt marshes, make conventional C-14 dating of salt marsh peats in Maine a problematic affair. This study implies that AMS dates may be needed to verify Holocene sea-level curves from other coastal areas that have hitherto been based solely on conventional C-14 peat dates.

  4. Mobile geophysical study of peat deposits in Fuhrberger Field, Germany

    NASA Astrophysics Data System (ADS)

    Wunderlich, T.; Petersen, H.; Hagrey, S. A. al; Rabbel, W.

    2012-04-01

    In the water protection area of Fuhrberger Field, north of Hanover, geophysical techniques were applied to study the stakeholder problem of the source detection for nitrate accumulations in the ground water. We used our mobile multisensor platform to conduct measurements using Ground Penetrating Radar (GPR, 200 MHz antenna) and Electromagnetic Induction (EMI, EM31). This aims to study the subsurface occurrences of peat deposits (surplus of organic carbon) supposed to be a source of nitrate emissions due to the aeration and the drawdown of groundwater levels (e.g. by pumping, drainage etc.). Resulting EMI and GPR signals show high data quality. Measured apparent electrical conductivity shows very low values (<10 mS/m) due to the mainly sandy subsurface. For this medium, both methods are expected to penetrate down to 3-5 m depth. GPR radargrams, time slices of GPR reflection energy and EMI apparent electrical conductivities are plotted on aerial photographs and compared to each other's and with vegetation intensity. We could separate areas characterized by low reflection energy and high conductivity, and vice versa. Briefly, organic rich sediments such as peats are assumed to have a relative high conductivity and thus low GPR reflectivity. Some areas of local conductivity increase correspond to a deep reflection interface (as seen in the radargrams), which even vanishes due to the high attenuation caused by the high conductivity. This implies that the upper layer is more conductive than the lower layer. Several local areas with these characteristics are found at the study sites. We recommend shallow drillings at representative points to deliver the necessary confirmation with ground truth information. Acknowledgments: iSOIL (Interactions between soil related sciences - Linking geophysics, soil science and digital soil mapping) is a Collaborative Project (Grant Agreement number 211386) co-funded by the Research DG of the European Commission within the RTD activities of the FP7 Thematic Priority Environment.

  5. Actinobacterial Nitrate Reducers and Proteobacterial Denitrifiers Are Abundant in N2O-Metabolizing Palsa Peat

    PubMed Central

    Palmer, Katharina

    2012-01-01

    Palsa peats are characterized by elevated, circular frost heaves (peat soil on top of a permanently frozen ice lens) and are strong to moderate sources or even temporary sinks for the greenhouse gas nitrous oxide (N2O). Palsa peats are predicted to react sensitively to global warming. The acidic palsa peat Skalluvaara (approximate pH 4.4) is located in the discontinuous permafrost zone in northwestern Finnish Lapland. In situ N2O fluxes were spatially variable, ranging from 0.01 to −0.02 μmol of N2O m−2 h−1. Fertilization with nitrate stimulated in situ N2O emissions and N2O production in anoxic microcosms without apparent delay. N2O was subsequently consumed in microcosms. Maximal reaction velocities (vmax) of nitrate-dependent denitrification approximated 3 and 1 nmol of N2O per h per gram (dry weight [gDW]) in soil from 0 to 20 cm and below 20 cm of depth, respectively. vmax values of nitrite-dependent denitrification were 2- to 5-fold higher than the vmax nitrate-dependent denitrification, and vmax of N2O consumption was 1- to 6-fold higher than that of nitrite-dependent denitrification, highlighting a high N2O consumption potential. Up to 12 species-level operational taxonomic units (OTUs) of narG, nirK and nirS, and nosZ were retrieved. Detected OTUs suggested the presence of diverse uncultured soil denitrifiers and dissimilatory nitrate reducers, hitherto undetected species, as well as Actino-, Alpha-, and Betaproteobacteria. Copy numbers of nirS always outnumbered those of nirK by 2 orders of magnitude. Copy numbers of nirS tended to be higher, while copy numbers of narG and nosZ tended to be lower in 0- to 20-cm soil than in soil below 20 cm. The collective data suggest that (i) the source and sink functions of palsa peat soils for N2O are associated with denitrification, (ii) actinobacterial nitrate reducers and nirS-type and nosZ-harboring proteobacterial denitrifiers are important players, and (iii) acidic soils like palsa peats represent reservoirs of diverse acid-tolerant denitrifiers associated with N2O fluxes. PMID:22660709

  6. Testing the potential of bacterial branched tetraether membrane lipids as temperature proxy in peat and immature coal deposits

    NASA Astrophysics Data System (ADS)

    Weijers, J. W. H.; Steinmann, P.; Hopmans, E. C.; Basiliko, N.; Finkelstein, S. A.; Johnson, K. R.; Schouten, S.; Sinninghe Damsté, J. S.

    2012-04-01

    Branched glycerol dialkyl glycerol tetraether (brGDGT) membrane lipids occur ubiquitously in peat and soil. In soil, the degree of methylation and cyclisation of branched tetraethers (MBT index and CBT ratio, respectively) has shown to relate to both soil pH and annual mean air temperature (MAT). Using this relation, past annual MATs can be reconstructed by analysing brGDGTs in marine sediment records near large river outflows. More recently, the potential of this MBT/CBT proxy is also being explored in lakes. Despite being more abundant in peat than soils, however, the utility of the proxy has not yet been fully explored in peat records. Present day peat records generally extent back to the early Holocene, but if the MBT/CBT proxy were shown to be applicable in peat deposits, there is also potential to apply it to immature coal deposits like lignites, which could provide valuable snapshots of continental climate back to the early Cenozoic. Here results are presented of analyses of different peats in south eastern Canada, showing that the pH of peat along a nutrient gradient is rather well reflected by the CBT. Annual MAT reconstructions based on the MBT/CBT soil calibration, however, tend to overestimate measured MAT. This is also the case for peat analysed from the surface of Etang de la Gruère peat bog in the Swiss Jura Mountains. Along the 6m depth profile of this bog (~13ka), CBT-reconstructed pH is compared with in-situ measured pore water pH showing that the brGDGT composition does not reflect present-day in-situ conditions. Instead, it reflects a stratigraphic boundary between Carex and Sphagnum dominated peat at 4 m depth that is not present in the pore water profile, testifying to a 'fossil' nature of the brGDGTs down the peat bog. Analyses of three immature coals of the Argonne Premium Coal Series reveal that branched GDGTs are present in the most immature coal, the Beulah Zap lignite (Ro = 0.25%), and only just above detection limit in the Wyodak Anderson coal (Ro = 0.32%), both of about the same age (Late Palaeocene). In the more mature Illinois #6 coal (Ro = 0.46%), brGDGTs are completely absent. In the Denver Basin, a comparison is made between outcrop and drilled core samples of Palaeocene lignites. BrGDGTs are preserved in the core samples, although in low quantities compared to peat. Outcrop samples are clearly overprinted by modern soil derived brGDGTs, despite digging a meters deep trench, which shows the need to obtain fresh non-weathered samples by coring. Reconstructed annual MAT for both the Beulah Zap and the Denver Basin lignites are several degrees higher than estimates based on leaf margin and oxygen isotope analyses from the same sites. Both reconstructions do testify, nevertheless, to the warm continental conditions during the early Cenozoic of the central U.S.A.. Although further validation is required, potentially in the form of a specific peat calibration, these results do show potential for application of the MBT/CBT temperature proxy in peat and lignite deposits.

  7. Evaluating the impacts of re-vegetation of bare peat on blanket peat water tables

    NASA Astrophysics Data System (ADS)

    Shuttleworth, Emma; Richards, Rebecca; Evans, Martin; Agnew, Clive; Pilkington, Mike; Maskill, Rachael; Allott, Tim

    2015-04-01

    Studies of the hydrological impacts of peat restoration in blanket peat systems have focused on the impacts of drain and gully blocking on water tables. However, in the South Pennines of the UK large areas of previously bare blanket peat have been restored by re-vegetation. The effects of this restoration treatment on water table behaviour have not been fully evaluated. Preliminary data from space-for-time studies indicate that re-vegetation leads to significant rises in water tables and decreases in water table variability. Here we present additional data from a before-after-control-intervention (BACI) study to validate these preliminary observations. We also present meteorological, net radiation and evapotranspiration data to test the hypothesis that water table changes associated with re-vegetation are driven by changing evapotranspiration rates as bare peat surfaces re-vegetate. The wider ecosystem service benefits of water table increases associated with re-vegetation of bare peat are discussed.

  8. Greenhouse gas efflux from an impacted Malaysian tropical peat swamp (Invited)

    NASA Astrophysics Data System (ADS)

    Waldron, S.; Vihermaa, L. E.; Evers, S.; Garnett, M.; Newton, J.; Padfield, R.

    2013-12-01

    Tropical peatlands constitute ~11% of global peatland area and ~12% of the global peat C pool. Malaysia alone contains 10% of tropical peats. Due to rising global demands for food and biofuels, SE-Asia peat swamp forest ecosystems are threatened by increasing amounts of drainage, fire and conversion to plantation. These processes can change the GHG emissions and thus net ecosystem C balance. However, in comparison to temperate and boreal peatlands, there is a lack of data on terrestrial-aquatic-atmospheric carbon transfer from tropical peatlands, both those that are little disturbed and those facing anthropogenic pressures. Lateral transport of soil-respired carbon, and fluvial respiration or UV-oxidation of terrestrial DOC primes atmospheric carbon dioxide efflux. We now know that DOC lost from disturbed tropical peat swamp forests can be centuries to millennia old and originates deep within the peat column - this carbon may fuel efflux of old carbon dioxide and so anthropogenic land-use change renders the older, slower carbon cycles shorter and faster. Currently we have no knowledge of how significant ';older-slower' terrestrial-aquatic-atmospheric cycles are in disturbed tropical peatlands. Further, in some areas for commercial reasons, or by conservation bodies trying to minimise peat habitat loss, logged peats have been left to regenerate. Consequently, unpicking the legacy of multiple land uses on magnitude, age and source of GHG emissions is challenging but required to support land management decisions and projections of response to a changing climate. Here, we present the results of our first field campaign in July 2013 to the Raja Musa and Sungai Karang Peat Swamp Forest Reserves in North Selangor, Malaysia. This is one of Malaysia's largest oceanic peat swamps, and has been selectively logged and drained for 80 years, but is now subject to a 30 year logging ban to aid forest regeneration and build up wood stocks. From sites subject to different land use, we will present measurements of i) spatial variation in fluvial carbon dioxide and methane concentrations and associated efflux rates, and ii) the stable carbon isotopic composition of DIC and novel determination of the age of the effluxed carbon dioxide. From this we can consider if younger-faster or older-slower carbon cycling dominates the terrestrial-aquatic-atmospheric C transfer during this dry period sampling.

  9. The S-transform: a Tool for Assessing Local Changes in Biogenic Gas Content in Peat from GPR Data?

    NASA Astrophysics Data System (ADS)

    Terry, N.; Zhongjie, Y.; Slater, L. D.

    2013-12-01

    Time-domain analysis of ground penetrating radar (GPR) data has been used to infer variation in biogenic gas content in peat soils. We examine the potential of frequency-domain methods for further assessing biogenic gas variation from GPR data. In particular, the S-transform is an algorithm to assess time-dependent frequency content. Each returned GPR trace is a time-series, therefore it is straightforward to compute frequency content of a returned radar trace to see how frequency content varies along that trace. The physical properties of soils will affect the frequency content of returned ground penetrating radar signals. Specifically, we postulate that development of gas bubbles in peat will cause preferential attenuation of the high frequency portion of the returned signal as a result of signal scattering. Laboratory results from a time-lapse GPR transmission study are presented. In this study, 1200 MHz antennas were used to sample a ~0.25 m by 0.25 m peat block taken from Caribou Bog, Maine for eight weeks on a twice daily basis. Data were collected across an upper, middle and lower section of the peat at three horizontal positions. Meanwhile, a dynamic chamber system was used to monitor methane flux from the peat surface. The frequency content of GPR data shows a clear correspondence with the dynamic chamber gas flux measurements. In particular, total methane flux shows an increasing trend for the duration of the experiment; these changes coincide with increases in low-frequency (500-1000 MHz) S-transform amplitudes primarily focused within a particular region of the peat block. These results suggest that the S-transform is a useful tool for monitoring changes in biogenic gas content in peat soils where time-lapse GPR data are available.

  10. Sensitivity of blanket peat vegetation and hydrochemistry to local disturbances.

    PubMed

    Robroek, Bjorn J M; Smart, Richard P; Holden, Joseph

    2010-10-01

    At the ecosystem scale, peatlands can be extremely resilient to perturbations. Yet, they are very sensitive to local disturbances, especially mechanical perturbations (e.g. trampling). The effects of these disturbances on vegetation, and potential effects on hydrochemical conditions along the peat surface, however, are largely unknown. We used three research tracks (paths researchers use to access their study sites) differing in time of abandonment to investigate the impact of local disturbance (trampling) on the vegetation and its short-term (< or = 2 year) recovery in a flagship research blanket peatland. Additionally, we examined the effects of local disturbance on fluvial runoff events and the concentrations of dissolved organic carbon (DOC) and particulate organic carbon (POC) in runoff water. Local disturbance heavily impacted peat vegetation, resulting in large areas of scarred and churned peat. Recovery of vascular plants along abandoned tracks was slow, but a functional Sphagnum layer re-established after just one year. The absence of vegetation elicited an increase in the number of runoff events along the tracks, by which POC runoff from the tracks increased. POC concentrations were highest in the surface water from the recently abandoned track, while they were low in the runoff water from the track abandoned longest and the undisturbed control track. We attribute this to the relatively fast recovery of the Sphagnum vegetation. DOC concentrations did not differ significantly either spatially or temporally in surface runoff or soil solution waters. While at an ecosystem scale local disturbances may be negligible in terms of carbon loss, our data points to the need for further research on the potential long-term effects of local disturbance on the vegetation, and significant effects on local scale carbon fluxes. Moreover, the effects of disturbances could be long-lasting and their role on ecosystem processes should not be underestimated. PMID:20692016

  11. Impact of prescribed burning on blanket peat hydrology

    NASA Astrophysics Data System (ADS)

    Holden, Joseph; Palmer, Sheila M.; Johnston, Kerrylyn; Wearing, Catherine; Irvine, Brian; Brown, Lee E.

    2015-08-01

    Fire is known to impact soil properties and hydrological flow paths. However, the impact of prescribed vegetation burning on blanket peatland hydrology is poorly understood. We studied 10 blanket peat headwater catchments. Five were subject to prescribed burning, while five were unburnt controls. Within the burnt catchments, we studied plots where the last burn occurred ˜2 (B2), 4 (B4), 7 (B7), or greater than 10 years (B10+) prior to the start of measurements. These were compared with plots at similar topographic wetness index locations in the control catchments. Plots subject to prescribed vegetation burning had significantly deeper water tables (difference in means = 5.3 cm) and greater water table variability than unburnt plots. Water table depths were significantly different between burn age classes (B2 > B4 > B7 > B10+) while B10+ water tables were not significantly different to the unburnt controls. Overland flow was less common on burnt peat than on unburnt peat, recorded in 9% and 17% of all runoff trap visits, respectively. Storm lag times and hydrograph recession limb periods were significantly greater (by ˜1 and 13 h on average, respectively) in the burnt catchments overall, but for the largest 20% of storms sampled, there was no significant difference in storm lag times between burnt and unburnt catchments. For the largest 20% of storms, the hydrograph intensity of burnt catchments was significantly greater than those of unburnt catchments (means of 4.2 × 10-5 and 3.4 × 10-5 s-1, respectively), thereby indicating a nonlinear streamflow response to prescribed burning. Together, these results from plots to whole river catchments indicate that prescribed vegetation burning has important effects on blanket peatland hydrology at a range of spatial scales.

  12. Functioning of microbial complexes in aerated layers of a highmoor peat bog

    NASA Astrophysics Data System (ADS)

    Golovchenko, A. V.; Bogdanova, O. Yu.; Stepanov, A. L.; Polyanskaya, L. M.; Zvyagintsev, D. G.

    2010-09-01

    Monitoring was carried out using the luminescent-microscopic method of the abundance parameters of different groups of microorganisms in a monolith and in the mixed layers of a highmoor peat bog (oligotrophic residual-eutrophic peat soil) in a year-long model experiment. The increase of the aeration as a result of mixing of the layers enhanced the activity of the soil fungi. This was attested to by the following changes: the increase of the fungal mycelium length by 6 times and of the fungal biomass by 4 times and the double decrease of the fraction of spores in the fungal complex. The response of the fungal complex to mixing was different in the different layers of the peat bog. The maximal effect was observed in the T1 layer and the minimal one in the T2 layer. The emission of CO2 in the mixed samples was 1.5-2 times higher than that from the undisturbed peat samples. In contrast with the fungi, the bacteria and actinomycetes were not affected by the aeration of the highmoor layers.

  13. Heterotrophic respiration in drained tropical peat temperatures influenced by shading gradient

    NASA Astrophysics Data System (ADS)

    Jauhiainen, Jyrki; Kerojoki, Otto; Silvennoinen, Hanna; Limin, Suwido; Vasander, Harri

    2015-04-01

    Lowland peatlands in Southeast Asia constitute a highly concentrated carbon (C) pool of global significance. These peatlands have formed over periods of several millennia by forest vegetation tolerant to flooding and poor substrates. Uncontrollable drainage and reoccurring wild fires in lack of management after removal of forest cover has impaired the C-storing functions in large reclaimed areas. Intergovernmental Panel on Climate Change (IPCC) reporting sees drained tropical organic soils as one of the largest greenhouse gas emissions releasing terrestrial systems. Vast areas of deforested tropical peatlands do not receive noteworthy shading by vegetation, which increases the amount of solar radiation reaching the peat surface. We studied heterotrophic carbon dioxide (CO2), nitrous oxide (N2O) and methane (CH4) fluxes in tropical peat in conditions, where; (i) peat temperatures were modified by artificial shading (no shade, 28%, 51% and 90% from the full sun exposure), (ii) root respiration was minimized, (iii) nutrient availability for peat decomposer community was changed (NPK fertilization of 0 and 313 kg ha-1). The experiment was repeated at two over 20 years ago drained fallow agricultural- and degraded sites in Central Kalimantan, Indonesia. Enhanced shading created a lasting decrease in peat temperatures, and decreased diurnal temperature fluctuations, in comparison to less shaded plots. The largest peat temperature difference was between the unshaded and 90% shaded peat surface, where the average temperatures within the topmost 50-cm peat profile differed 3 °C, and diurnal temperatures at 5 cm depth varied up to 4.2 °C in the unshaded and 0.4 °C in the 90% shaded conditions. Highest impacts on the heterotrophic CO2 fluxes caused by the treatments were on agricultural land, where 90% shading from the full exposure resulted in a 33% lower CO2 emission average on the unfertilised plots and a 66% lower emission average on the fertilised plots. Correlation between peat temperature and CO2 flux suggested an approximately 8% (unfertilised) and 25% (fertilised) emissions change for each 1 °C temperature change at 5 cm depth on the agricultural land. CO2 flux responses to the treatments remained low or were inconsistent over the peat temperature range.. Fertilised conditions negatively correlated with N2O efflux with increases in temperature, suggesting a 12-36% lower efflux for each 1 °C increase in peat temperature (at 5 cm depth) at the sites. Despite the apparently similar landscapes of fallow agricultural land and degraded peatland sites, the differences in greenhouse gas dynamics are expected to be an outcome of the long-term management differences. Based on the results it is possible to seek management practices that prolong timespan for using drained tropical peat for cultivation, simultaneously reduce negative climate impacts created from peat substrate carbon loss, and also improve greenhouse gas monitoring techniques at field.

  14. Fixed-bed gasification research using US coals. Volume 11. Gasification of Minnesota peat. [Peat pellets and peat sods

    SciTech Connect

    Thimsen, D.; Maurer, R.E.; Pooler, A.R.; Pui, D.; Liu, B.; Kittelson, D.

    1985-05-01

    A single-staged, fixed-bed Wellman-Galusha gasifier coupled with a hot, raw gas combustion system and scrubber has been used to gasify numerous coals from throughout the United States. The gasification test program is organized as a coooperative effort by private industrial participants and governmental agencies. The consortium of participants is organized under the Mining and Industrial Fuel Gas (MIFGa) Group. This report is the eleventh volume in a series of reports describing the atmospheric pressure, fixed-bed gasification of US coals. This specific report describes the gasification of peat pellets and peat sods during 3 different test periods. 2 refs., 20 figs., 13 tabs.

  15. Hydrology of peat-forming wetlands in Scotland.

    PubMed

    Bragg, O M

    2002-07-22

    Peatlands cover approximately 14% of Scotland, although only part of this area is active (peat-forming) mire. Mires are important for the biodiversity of the specialist plant and animal communities they support. Study of mire ecosystems has revealed intimate relationships between their organic components and water, which mean that it is impossible to understand their ecology without considering hydrology. Whilst ecohydrological studies have concentrated on the internal functioning of mires, the insights gained are relevant to runoff generation in peat-covered river catchments. This paper reviews our knowledge of processes occurring in mires and relates these to wider catchment hydrology, on the basis of published information and recent research in Scotland. The influence of different types of land management is considered, and it emerges that mire is most effective in delaying storm run-off, in preventing soil erosion and in retaining inorganic nutrients when it is undrained; although there can be adverse effects on water quality under certain conditions. In the context of global warming, mire ecosystems are sensitive but at the same time robust to climate change, and thus contain archives of climatic data for the Holocene. Moreover, peatlands store significant quantities of carbon, and influence directly the concentrations of greenhouse gases in the atmosphere. Various issues related to conservation and restoration of peatland biodiversity have been addressed constructively in recent decades, although approaches and objectives are not always consistent between sites. These are reviewed, and some outstanding issues and research needs are identified. PMID:12169001

  16. Effect of peat quality on microbial greenhouse gas formation in an acidic fen

    NASA Astrophysics Data System (ADS)

    Reiche, M.; Gleixner, G.; Ksel, K.

    2009-09-01

    Peatlands play an important role in the global carbon cycle and represent both an important stock of soil carbon and a substantial natural source of relevant greenhouse gases like CO2 and CH4. While it is known that the microbial availability of organic matter affects degradation and mineralization processes in peatlands, the manner in which peat organic matter affects the formation of CO2 and CH4 remains unclear. In this study we developed a fast and simple peat quality index in order to estimate its greenhouse gas potential by linking the thermo-degradability of peat with anaerobic CO2 and CH4 formation rates. Peat samples were obtained at several depths (0-40 cm) at four sampling locations from an acidic fen (pH∼4.7). CO2 and CH4 formation rates were highly spatially variable and depended on depth, sampling location, and the composition of pyrolysable organic matter. Peat samples active in CO2 and CH4 formation had a quality index above 1.35, and the fraction of thermally labile pyrolyzable organic matter (comparable to easily available carbon substrates for microbial activity) obtained by thermogravimetry was above 35%. Curie-point pyrolysis-gas chromatography/mass spectrometry mainly identified carbohydrates and lignin as pyrolysis products in these samples, indicating that undecomposed organic matter was found in this fraction. In contrast, lipids and unspecific pyrolysis products, which indicate recalcitrant and highly decomposed organic matter, correlated significantly with lower CO2 formation and reduced methanogenesis. Our results suggest that undecomposed organic matter is a prerequisite for CH4 and CO2 development in acidic fens. Furthermore, the new peat quality index should aide the estimation of greenhouse gas formation potential resulting from peatland restoration and permafrost thawing and help yield more robust models of trace gas fluxes from peatlands for climate change research.

  17. Effect of peat quality on microbial greenhouse gas formation in an acidic fen

    NASA Astrophysics Data System (ADS)

    Reiche, M.; Gleixner, G.; Ksel, K.

    2010-01-01

    Peatlands play an important role in the global carbon cycle and represent both an important stock of soil carbon and a substantial natural source of relevant greenhouse gases like CO2 and CH4. While it is known that the quality of organic matter affects microbial degradation and mineralization processes in peatlands, the manner in which the quality of peat organic matter affects the formation of CO2 and CH4 remains unclear. In this study we developed a fast and simple peat quality index in order to estimate its potential greenhouse gas formation by linking the thermo-degradability of peat with potential anaerobic CO2 and CH4 formation rates. Peat samples were obtained at several depths (0-40 cm) at four sampling locations from an acidic fen (pH 4.7). CO2 and CH4 formation rates were highly spatially variable and depended on depth, sampling location, and the composition of pyrolysable organic matter. Peat samples active in CO2 and CH4 formation had a quality index above 1.35, and the fraction of thermally labile pyrolyzable organic matter (comparable to easily available carbon substrates for microbial activity) obtained by thermogravimetry was above 35%. Curie-point pyrolysis-gas chromatography/mass spectrometry mainly identified carbohydrates and lignin as pyrolysis products in these samples, indicating that undecomposed organic matter was found in this fraction. In contrast, lipids and unspecific pyrolysis products, which indicate recalcitrant and highly decomposed organic matter, correlated significantly with lower CO2 formation and reduced methanogenesis. Our results suggest that undecomposed organic matter is a prerequisite for CH4 and CO2 development in acidic fens. Furthermore, the new peat quality index should aide the estimation of potential greenhouse gas formation resulting from peatland restoration and permafrost thawing and help yield more robust models of trace gas fluxes from peatlands for climate change research.

  18. Understanding the spatial structure of peat permeability around natural pipes in blanket peatlands

    NASA Astrophysics Data System (ADS)

    Cunliffe, Andrew; Baird, Andy; Holden, Joseph

    2014-05-01

    Understanding the spatial structure of peat permeability around natural pipes in blanket peatlands We present the results of a detailed investigation of fine-scale variations in the permeability or hydraulic conductivity (K) of the peat around a natural pipe in a blanket peatland. Both vertical K and horizontal K ranged over seven orders of magnitude over scales of decimetres. K was found to be more variable than indicated by previous research. This finding has important implications for the approaches currently employed to investigate peatland hydrological processes, and the parameterisation of models used to simulate these complex ecohydrological systems. We also observed considerable spatial structuring in K. Lateral K parallel to the pipe was significantly greater than lateral K perpendicular to the pipe. Critically, a wedge of poorly-humified, high-permeability peat was present directly above the pipe, forming a hydrological connection between the peatland surface and the perennially-flowing pipe. These observations advance our mechanistic understanding of pipeflow generation in peatlands. We also attempted to investigate K across the pipe-peat interface to test for a hypothesised low-K skin; however, this was precluded by sample length dependency, which suggests that it is inappropriate to compare K measurements between peat samples of different lengths. Overall, we argue that high resolution work such as this is required for the development of more accurate perceptual models of peatland hydrological systems. Cunliffe, A. M., A. J. Baird, and J. Holden (2013), Hydrological hotspots in blanket peatlands: Spatial variation in peat permeability around a natural soil pipe, Water Resources Research, Vol.49, doi:10.1002/wrcr.20435.

  19. Carbon dioxide and methane fluxes in drained tropical peat before and after hydrological restoration.

    PubMed

    Jauhiainen, Jyrki; Limin, Suwido; Silvennoinen, Hanna; Vasander, Harri

    2008-12-01

    Present tropical peat deposits are the outcome of net carbon removal from the atmosphere and form one of the largest terrestrial organic carbon stores on the Earth. Reclamation of pristine tropical peatland areas in Southeast Asia increased strikingly during the last half of the 20th century. Drainage due to land-use change is one of the main driving factors accelerating carbon loss from the ecosystem. Dams were built in drainage-affected peatland area canals in Central Kalimantan, Indonesia, in order to evaluate major patterns in gaseous carbon dioxide and methane fluxes and in peat hydrology immediately before and after hydrologic restoration. The sites included peat swamp forest and deforested burned area, both affected by drainage for nearly 10 years. Higher annual minimum soil water table levels prevailed on both sites after restoration; the deforested site water table level prevailed considerably longer near the peat surface, and the forest water table level remained for a longer period in the topmost 30 cm peat profile after restoration. Forest soil gas fluxes were clearly higher in comparison to the deforested area. Cumulative forest floor CO2 emissions (7305-7444 g x m(-2) x yr(-1); 166.0-169.2 mol CO2 x m(-2) x yr(-1)) and the deforested site CO2 emissions (2781-2608 g x m(-2) x yr(-1); 63.2-59.3 mol CO2 x m(-2) x yr(-1)) did not markedly reflect the notably differing hydrological conditions the year before and after restoration. The forest floor was a weak CH4 sink (-0.208 to -0.368 g x m(-2) x yr(-1); -13.0 to -22.9 mmol CH4 x m(-2) x yr(-1)) and the deforested site a comparable CH4 source (0.197-0.275 g x m(-2) x yr(-1); 12.3-17.1 mmol CH4 x m(-2) x yr(-1)) in the study period. In general, higher soil water table levels had a relatively small effect on the annual CH4 emission budgets. In the two site types the gas flux response into hydrological conditions in degraded tropical peat can be attributed to differing CO2 and CH4 dynamics, peat physical characteristics, and vegetation. PMID:19137955

  20. Immunomodulative properties of humic peat preparations

    NASA Astrophysics Data System (ADS)

    Stepchenko, L. M.; Syedykh, N. J.

    2010-05-01

    It is proved, that the humic peat preparations promote the resistance of plants, animals and poultry to the influence of both abyotyc and byotyc extreme factors of external environment, to action. It was shown by us before, that biologically active compounds from peat promote stability against different diseases of agricultural animals and poultry. We conducted researches of humic preparations influence (hydrohumate and oxyhumate) on several indexes of immunoreactivity of the organisms of chickens broilers, ostriches, cows and laboratory rats. It is found out, that adding of humic preparations to forage or drinking water results in the normalization of immunity indexes; in particular, leucocytes level, in the increase of the level of some classes of immunoglobuline in blood, of haemoglobin level, T- and B-lymphocytes level, as well as common unspecific resistance - lyzocymic, phagocytic and bactericidic activity. These results allow to suggest that the peat humic preparations show immunomodulative activity, influencing both on humoral and cel immunity links.

  1. Comparison on the performance of five different electromagnetic sensors in sphagnum peat

    NASA Astrophysics Data System (ADS)

    Daniela, Reineke; Weber, Tobias K. D.; Durner, Wolfgang

    2014-05-01

    Electromagnetic (EM) soil moisture sensors are widely used to measure water contents in porous media, particularly in field studies. The accurate determination of saturation states in soils is vital for many environmentally related research questions. Electromagnetic water content measurements are based on the determination of the dielectric permittivity of a medium. As the dielectric permittivity is high in water compared to other soil constituents it can be related to soil water content. However, this method is affected by the properties of the medium investigated and until now there is little knowledge about its applicability to peat soils. The aim of our study was to investigate the performance of electromagnetic sensors to measure water content in sphagnum peat and to identify problems of the EM method associated with this special substrate. For this purpose, a comparison under laboratory conditions was conducted. Five different commercially available types of soil moisture sensor were selected with a range of geometries and various measurement principles. These included a time domain reflectometry probe, IMKO Trime Pico 64, and four frequency domain technique devices, namely the Stevens Hydra Probe, Delta-T Wet-2, Decagon 5TM and Decagon GS3. For this a sphagnum sample (40 cm by 60 cm by 30 cm), taken from a soli-ombrotrophic peat bog, was instrumented with the five sensor types at two different depths. Water content was altered by continuous evaporation at the top. To check the water content readings for plausibility, matrix potentials in four depths and the weight of the sample were monitored during the evaporation experiment. The dielectric permittivity readings from the soil moisture sensors were converted to volumetric water content either by calibration equations for organic substrates supplied by the manufacturer or from calibration equations for sphagnum found in scientific publications. In both parameters, dielectric permittivity and volumetric water content, large systematic differences between the sensor types were observed, especially in the wet range. With four sensor types giving plausible results in both measurement depths, one sensor type gave unplausible readings during most of the experiment. While the earlier suggests that a sphagnum- and possibly peat type specific calibration equation for each sensor might be necessary, the latter indicates that some sensor geometries could be inappropriate for peat soils.

  2. Critical comparison of peat decomposition proxies and their relationship to peat geochemistry

    NASA Astrophysics Data System (ADS)

    Bindler, Richard; Hansson, Sohia

    2013-04-01

    Mires are known to play a major role in global carbon cycling, and there is an important link between the carbon mass balance of mires and climate. Aspects of this coupling are preserved in the peat that accumulates in mires, and in particular the record of decomposition of organic matter is used as an important proxy for reconstructing this climate-carbon coupling. The geochemical record of major and trace elements in peat is also used as a proxy for other environmental forcings, especially natural and anthropogenic atmospheric inputs on mires, such as soil dust and lead pollution, respectively. However, the geochemical composition of the peat can be influenced by changes in the decomposition of organic matter, which can potentially alter the retention and mobility of trace elements of interest, such as mercury. To understand past climate-carbon interactions and decomposition effects on geochemistry requires quantitative assessments of decomposition. There is, however, no single measurement for decomposition, but rather a range of qualitative proxies is used to estimate mass loss and decomposition. The most common techniques include CN ratios, bulk density and light transmission following an alkaline extract. In this presentation we compare these three proxies in cores from two sites: an oligotrophic mire where we to