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1

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

NASA Astrophysics Data System (ADS)

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.

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

2007-06-01

2

Soil zonality of the Chukotka Upland  

NASA Astrophysics Data System (ADS)

The vertical soil-geographic zonality of the Chukotka Upland in the area of the Amguema River valley can be considered a model vertical zonality in the Low Arctic regions at the interface between the continental and oceanic climates. The plain bottom of the valley has a continental climate. The surrounding mountains are under the influence of an oceanic climate, which is more pronounced in the low mountains and less pronounced in the medium-high mountains. Three altitudinal soil zones are distinguished: (1) the plain Subarctic zone with the absolute heights below 200-400 m a.s.l., where cryoturbated humus-impregnated peat-mucky gleyzems are developed from loamy substrates, and gleyed soddy podburs are developed from loamy sandy substrates; (2) the low-mountain zone of a creeping alder forest (the forest-tundra zone?) of the Low Arctic at the heights of 400-700 m a.s.l., where mucky-gray-humus humus-impregnated podzolized gleyzems are developed under tundra patches, cryoturbated peat-mucky high-humus-impregnated podzolized gleyzems are developed under creeping alder thickets, and pedoliths are exposed in the zones of landslides; and (3) the mountain Middle Arctic zone at elevations above 700 m a.s.l., where very thin soil films predominate; gray-humus cryometamorphic lithozems are developed from the eluvium of magmatic rocks, and humus-impregnated cryometamorphic soils with quicksand suprapermafrost horizons are developed from the eluvium of hard sedimentary rocks.

Karavaeva, N. A.

2013-05-01

3

The role of common upland vegetation on gaseous carbon cycling on UK blanket peat bogs  

NASA Astrophysics Data System (ADS)

The most important control upon the carbon dynamics of any peatland is vegetation. However there is a gap in the literature with respect to comparative, in-situ studies of common upland vegetation types on peat bogs from a carbon cycling perspective. Where studies exist they tend to be narrowly focused (i.e. on one or two species or a small geographical area) or are laboratory manipulation studies. This study set out to compare gaseous CO2 exchange, in situ, across a broad (geographic) range of sites dominated by differing, common, upland vegetation types. The vegetation types studied were; Calluna vulgaris, Sphagnum spp., Eriophorum (E. angustifolium + E. vaginatum), Molinia caerulea and areas revegetated with a lawn grass mixture that was used for restoration (Festuca spp, Deschampsia spp. and Agrostis spp.).The primary aim of the study was to assess the carbon cycling potential of the common upland vegetation types, in order to produce clearer evidence as to which upland species produce the most efficient carbon sinks. The study was carried out in the South Pennines and Peak District of England. All readings were taken from upland-blanket peat bogs, as this type of bog accounts for 87% of the UK's peatlands, and therefore the results of this study can have the widest possible applicability to the rest of the UK's peat reserves. NEE and NER measurements were taken with a PP Systems EMG-4 infra-red gas analyzer. PAR and air temperature readings were taken along side water table and soil pore water samples from every site. Each site was visited monthly for at least 12 months and between 3-9 replicates were recorded per site. The results of this study will deal with the effects vegetation has on NER, GPP and NEE, focusing on which vegetation types make the most efficient gaseous carbon sinks. Moreover the effect of vegetation on water table levels and water quality will be discussed. Finally a consideration of how the age of Calluna vulgaris affects the parameters above will be given.

Dixon, Simon; Rowson, James; Worrall, Fred

2010-05-01

4

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

NASA Astrophysics Data System (ADS)

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

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

2013-12-01

5

Peat  

USGS Publications Warehouse

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.

Apodaca, Lori E.

2013-01-01

6

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

PubMed

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

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

2007-02-01

7

Soil conservation and poverty: Lessons from upland Indonesia  

Microsoft Academic Search

Soil conservation efforts in Indonesia since the Dutch colonial era have focused on introducing bench terraces—a costly soil conservation method for poor, upland farmers. Data from two villages in the Kerinci uplands of Sumatra illustrate that even with state underwriting of bench terrace construction, farmers across all economic strata still resist using this method. Why the state has not pursued

Jill M. Belsky

1994-01-01

8

Metatranscriptomic Analysis of Arctic Peat Soil Microbiota  

PubMed Central

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

Tveit, Alexander T.

2014-01-01

9

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

NASA Astrophysics Data System (ADS)

One of the key parameters controlling greenhouse gas (GHG) emissions from organic soils is water table depth. Thus, a detailed analysis of the hydrology is essential for an accurate spatial upscaling of the information of local GHG emission measurements to the regional and national scale. For the interpretation and numerical modeling of water table fluctuations, knowledge about soil hydraulic parameters is crucial. 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, it is difficult to describe peat soil moisture dynamics with standard hydraulic functions developed for mineral soils. The objective of this study was to determine soil hydraulic properties for various undisturbed peat columns (diameter: 30 cm, height: 20 cm). Laboratory evaporation experiments were conducted for peat soils from five different test sites of the German joint research project "Organic Soils". Due to different land use histories, the peat samples covered a broad range of degradation states, which is known to strongly influence peat soil hydraulic properties. Pressure head, moisture content, weight loss and water level were monitored during the evaporation experiment. In numerical simulations using HYDRUS-1D the experimental data were used for an inverse-estimation of the soil hydraulic parameters using "shuffled complex evolution" and "covariance matrix adaption" optimization schemes. Besides the commonly applied van Genuchten-Mualem parameterization, several alternative soil parameterizations are evaluated.

Dettmann, Ullrich; Frahm, Enrico; Bechtold, Michel

2013-04-01

10

Greenhouse gas emissions from cultivated peat soils in Sweden.  

E-print Network

??Greenhouse gas emissions and peat subsidence are major concerns both from an environmental perspective and for farmers with declining soil production capacity. Agricultural databases, digitised… (more)

Berglund, Örjan

2011-01-01

11

Peat soil properties and erodibility: what factors affect erosion and suspended sediment yields in peat extraction areas?  

NASA Astrophysics Data System (ADS)

Peatland drainage and peat extraction operations change soil properties and expose bare peat to erosion forces, resulting in increased suspended sediment (SS) loads to downstream water bodies. SS yields from peat extraction areas are known to vary significantly between sites, but the contribution of peat properties and catchment characteristics to this variation is not well understood. In this study, we investigated peat erosion at 20 Finnish peat extraction sites by conducting in situ and laboratory measurements on peat erodibility and associated peat properties (degree of humification, peat type, bulk density, loss on ignition, porosity, moisture content, and shear strength), and by comparing the results with monitored long-term SS concentrations and loads at each catchment outlet. Here, we used a cohesive strength meter (CSM) to measure direct erosion thresholds for undisturbed soil cores collected from each study site. The results suggested that the degree of peat decomposition clearly affects peat erodibility and explains much of the variation in SS concentration between the study sites. According to CSM tests, critical shear stresses for particle entrainment were lowest (on average) in well-decomposed peat samples, while undecomposed, dry and fiber rich peat generally resisted erosion very well. Furthermore, the results indicated that two separate critical shear stresses often exist in moderately decomposed peat. In these cases, the well-decomposed parts of peat samples eroded first at relatively low shear stresses and remaining peat fibers prevented further erosion until a much higher shear stress was reached. In addition to peat soil properties, the study showed that the erosion of mineral subsoil may play a key role in runoff water SS concentration at peat extraction areas with drainage ditches extending into the mineral soil. The interactions between peat properties and peat erodibility found in this study as well as critical shear stress values obtained can be used for several purposes in e.g. water conservation and sediment management planning for peat extraction areas and other bare peat-covered catchments.

Tuukkanen, Tapio; Marttila, Hannu; Kløve, Bjørn

2014-05-01

12

Correlations Between Chemical Weathering and Soil Production in Soil-Mantled, Upland Landscapes, Central California  

Microsoft Academic Search

Quantifying and understanding the coupling between chemical and mechanical weathering in soil-mantled, upland hillslope development is an area of active research. Recent work on hillslope development from soil-mantled, upland landscapes has observed that maximal soil production from bedrock occurs within a narrow range of soil depths. Here we present initial results from an extensive field and laboratory investigation seeking to

B. C. Burke

2002-01-01

13

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...

14

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

NASA Astrophysics Data System (ADS)

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 primry 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, 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.

Worrall, F.; Burt, T. P.; Clay, G. D.; Moody, C. S.

2015-01-01

15

The Influence of Dam Removal on Upland Soils  

NASA Astrophysics Data System (ADS)

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.

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

2011-12-01

16

Are calcareous soils in uplands less prone to damage from road salting than acidic soils?  

Microsoft Academic Search

Previous studies of upland roadside soils in Cumbria, that would normally be naturally acidic, have highlighted that (a) runoff from roads subjected to long-term road salting can dramatically raise soil pH down slope in upland areas; (b) the soil pH increase dramatically changes N cycling in soils down slope, increasing mineralisation of organic matter, ammonification, ammonium leaching down slope and

Sophie M. Green; Malcolm S. Cresser

2008-01-01

17

Global Change Simulations Affect Potential Methane Oxidation in Upland Soils  

Microsoft Academic Search

Atmospheric concentrations of methane (CH4) are higher now than they have ever been during the past 420,000 years. However, concentrations have remained stable since 1999. Emissions associated with livestock husbandry are unlikely to have changed, so some combination of reduced production in wetlands, more efficient capture by landfills, or increased consumption by biological CH4 oxidation in upland soils may be

J. C. Blankinship; B. A. Hungate

2004-01-01

18

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

NASA Astrophysics Data System (ADS)

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.

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

2013-12-01

19

Soil Data from Fire and Permafrost-Thaw Chronosequences in Upland Black Spruce (Picea mariana)  

E-print Network

Soil Data from Fire and Permafrost-Thaw Chronosequences in Upland Black Spruce (Picea mariana and Permafrost-Thaw Chronosequences in Upland Black Spruce (Picea mariana) Stands near Hess Creek and Tok in Upland Black Spruce (Picea mariana) Stands near Hess Cree

Ickert-Bond, Steffi

20

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

SciTech Connect

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).

Nikonov, V.V.

1981-01-01

21

Phenol oxidase activity in secondary transformed peat-moorsh soils  

NASA Astrophysics Data System (ADS)

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.

Sty?a, K.; Szajdak, L.

2009-04-01

22

[Response of mineralization of dissolved organic carbon to soil moisture in paddy and upland soils in hilly red soil region].  

PubMed

Typical paddy and upland soils were collected from a hilly subtropical red-soil region. 14C-labeled dissolved organic carbon (14C-DOC) was extracted from the paddy and upland soils incorporated with 14C-labeled straw after a 30-day (d) incubation period under simulated field conditions. A 100-d incubation experiment (25 degrees C) with the addition of 14C-DOC to paddy and upland soils was conducted to monitor the dynamics of 14C-DOC mineralization under different soil moisture conditions [45%, 60%, 75%, 90%, and 105% of the field water holding capacity (WHC)]. The results showed that after 100 days, 28.7%-61.4% of the labeled DOC in the two types of soils was mineralized to CO2. The mineralization rates of DOC in the paddy soils were significantly higher than in the upland soils under all soil moisture conditions, owing to the less complex composition of DOC in the paddy soils. The aerobic condition was beneficial for DOC mineralization in both soils, and the anaerobic condition was beneficial for DOC accumulation. The biodegradability and the proportion of the labile fraction of the added DOC increased with the increase of soil moisture (45% -90% WHC). Within 100 days, the labile DOC fraction accounted for 80.5%-91.1% (paddy soil) and 66.3%-72.4% (upland soil) of the cumulative mineralization of DOC, implying that the biodegradation rate of DOC was controlled by the percentage of labile DOC fraction. PMID:24984493

Chen, Xiang-Bi; Wang, Ai-Hua; Hu, Le-Ning; Huang, Yuan; Li, Yang; He, Xun-Yang; Su, Yi-Rong

2014-03-01

23

Humic acids and transformation processes of structure, peat water properties, peat soils under their dehydration-rewetting  

NASA Astrophysics Data System (ADS)

At the basis of the processes of structure transformation , water properties of peat systems (PS) during their dehydration (drying) or, on the contrary, humidifying there are mainly surface-like phenomena , namely: capillary forces; processes of interphase interaction (wetting), moisture, ions transfer in thin films, etc. Peat, peat soils are composite systems , containing basically humified vegetative residues in which, as a rule, humic matters ( substances) prevail (HS) representing unstructured organic formations of natural origin with a wide spectrum of ion-exchange centers, functional groups. Humic acids (HA) is a HS base component . It means, that having found specificity of the mechanism of HA action on PS physical and chemical properties it is obviously possible to operate properties of the last. In the course of agricultural use associates of peat in tillage horizon of peat soils are periodically exposed to drying-humidifying, i.e. periodically form compact structures at drying (being on a soil surface), and then periodically are exposed to the destruction at humidifying (being in sub-tillage horizon). Similar transformation of TS structure results in peat degradation and, as consequence, soil peat degradation, so, it activates their wind erosion, worsens agrophysical characteristics and, first of all, water properties. Rational use of peat soils obliges a science to working out actions to minimize organic substances of peat mineralization, i.e. minimizing CO2 sink and other derivatives of carbon into the atmosphere, subsoil waters. HA, TS transformation regularities at their dehydration -humidifying have been investigated by applying various methods of physical and chemical analysis.

Lishtvan, I. I.; Abramets, A. M.; Yanuta, J. G.; Monich, G. S.; Glukhova, N. S.; Emelyanenko, V. N.

2010-05-01

24

Peat fires as source of polycyclic aromatic hydrocarbons in soils  

NASA Astrophysics Data System (ADS)

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.

Tsibart, Anna

2013-04-01

25

Accounting for variability in soil microbial communities of temperate upland grassland ecosystems  

Microsoft Academic Search

This study aimed to determine the factors which regulate soil microbial community organisation and function in temperate upland grassland ecosystems. Soil microbial biomass (Cmic), activity (respiration and potential carbon utilisation) and community structure (phospholipid fatty acid (PLFA) analysis, culturing and community level physiological profiles (CLPP) (Biolog®)) were measured across a gradient of three upland grassland types; Festuca–Agrostis–Galium grassland (unimproved grassland,

S. J. Grayston; G. S. Griffith; J. L. Mawdsley; C. D. Campbell; R. D. Bardgett

2001-01-01

26

Soil CO2 production in upland tundra where permafrost is thawing Hanna Lee,1,2  

E-print Network

Soil CO2 production in upland tundra where permafrost is thawing Hanna Lee,1,2 Edward A. G. Schuur to understand the response of belowground C emissions for different soil depths from upland tundra as a result moist acidic tundra and highest where thawing of permafrost and thermokarst was most pronounced. We were

Wagner, Diane

27

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

NASA Astrophysics Data System (ADS)

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.

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

2012-04-01

28

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

NASA Astrophysics Data System (ADS)

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.

Tuukkanen, Tapio; Marttila, Hannu; Kløve, Bjørn

2014-04-01

29

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

NASA Astrophysics Data System (ADS)

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.

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

2013-04-01

30

[Extraction of Cd by ramie from soils as affected by applications of chelators and peat].  

PubMed

Pot experiments were performed to study the effectiveness of chelators (EDTA, citric acid) and peat in enhancing phyremediation of heavy metal Cd by ramie. The results showed that peat increased the ramie's biomass by improving soil's physical and chemical properties, and the relative yields of peat alone, chelators(EDTA, citric acid) combined with peat were 1.23, 1.13 and 1.41 respectively. So the combination of citric acid and peat was more useful for growth of the ramie. As far as improving Cd uptake was concerned, it seemed that the combination of chelators with peat significantly promoted Cd uptake by the plant, and the percent of changeable Cd in soil were 61.6% and 58.3% . In addition, it had better bioaccumulation effects to combine with chelators and peat, of which Cd bioaccumulation coefficients were 1.33 and 1.32, compared to 1.11, 1.11 and 1.05 in application of peat, EDTA and citric acid respectively. What's more, cadmium removal rates in soil were up to 1.13% and 1.22% respectively in applications of two kinds of chleators (EDTA, citric acid) combined with peat. Therefore, it had better effects of phytoremediation to accumulate more cadmium amounts by combining with citric acid and peat because of more biomass. In conclusion, the phytoremediation by ramie can be more effective when chelators and peat were combined and added to soils. PMID:19927838

Shen, Li-Ping; Zong, Liang-Gang; Jiang, Pei; Liu, Wei-Xing; Jiang, Bo; Chen, Ya-Hua

2009-09-15

31

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

NASA Astrophysics Data System (ADS)

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.

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

32

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

PubMed

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

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

33

Erosion of upland hillslope soil organic carbon: Coupling field measurements with a sediment transport model  

E-print Network

Erosion of upland hillslope soil organic carbon: Coupling field measurements with a sediment soil C measurements to quantify the erosion and temporal storage of soil organic carbon (SOC) within perturbation (Tennessee Valley (TV)) versus clay-rich soil creep (Black Diamond (BD)). The average SOC erosion

Heimsath, Arjun M.

34

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

PubMed Central

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

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

2014-01-01

35

Can carbon offsetting pay for upland ecological restoration?  

PubMed

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. PMID:19818993

Worrall, Fred; Evans, Martin G; Bonn, Aletta; Reed, Mark S; Chapman, Daniel; Holden, Joseph

2009-12-15

36

Global Change Simulations Affect Potential Methane Oxidation in Upland Soils  

NASA Astrophysics Data System (ADS)

Atmospheric concentrations of methane (CH4) are higher now than they have ever been during the past 420,000 years. However, concentrations have remained stable since 1999. Emissions associated with livestock husbandry are unlikely to have changed, so some combination of reduced production in wetlands, more efficient capture by landfills, or increased consumption by biological CH4 oxidation in upland soils may be responsible. Methane oxidizing bacteria are ubiquitous in upland soils and little is known about how these bacteria respond to anthropogenic global change, and how they will influence - or already are influencing - the radiative balance of the atmosphere. Might ongoing and future global changes increase biological CH4 oxidation? Soils were sampled from two field experiments to assess changes in rates of CH4 oxidation in response to global change simulations. Potential activities of CH4 oxidizing bacterial communities were measured through laboratory incubations under optimal temperature, soil moisture, and atmospheric CH4 concentrations (~18 ppm, or 10x ambient). The ongoing 6-year multifactorial Jasper Ridge Global Change Experiment (JRGCE) simulates warming, elevated precipitation, elevated atmospheric CO2, elevated atmospheric N deposition, and increased wildfire frequency in an annual grassland in a Mediterranean-type climate in central California. The ongoing 1-year multifactorial Merriam Climate Change Experiment (MCCE) simulates warming, elevated precipitation, and reduced precipitation in four different types of ecosystems along an elevational gradient in a semi-arid climate in northern Arizona. The high desert grassland, pinyon-juniper woodland, ponderosa pine forest, and mixed conifer forest ecosystems range in annual precipitation from 100 to 1000 mm yr-1, and from productivity being strongly water limited to strongly temperature limited. Among JRGCE soils, elevated atmospheric CO2 increased potential CH4 oxidation rates (p=0.052) and wildfire decreased rates (p=0.014). These responses may be explained by improved soil aggregate stability in the first case, and reduced aggregate stability in the latter case. No effects of warming, elevated precipitation, elevated N deposition, or multifactor interactions were found. Among MCCE soils, similarly, no effects of elevated or reduced precipitation were found. While warming did not affect low elevation ecosystems, it did significantly decrease rates in the highest elevation mixed conifer forest (p=0.004). This suggests a vulnerability of cold-adapted CH4 oxidizing bacteria to elevated temperature. However, bacterial communities in all sampled ecosystems appear to be resistant to drier conditions and unaffected by wetter conditions. If biological oxidation is responsible for the current stability in atmospheric CH4 concentrations, then the improved function of this global CH4 sink is likely driven by indirect plant effects under elevated atmospheric CO2. Improved function, however, may be absent or reversed in future ecosystems that experience increased wildfire frequency and in high altitude and latitude ecosystems that experience rapid warming.

Blankinship, J. C.; Hungate, B. A.

2004-12-01

37

Peat soil composition as indicator of plants growth environment  

Microsoft Academic Search

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

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

2009-01-01

38

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

Microsoft Academic Search

Everglades. Perhaps one of the more difficult obstacles of this proposal is the approach to ameliorate peat island A wetland restoration demonstration project examined the effects subsidence without adversely affecting drinking water of a permanently flooded wetland on subsidence of peat soils. The project, started in 1997, was done on Twitchell Island, in the Sacra- quality. mento-San Joaquin Delta of

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

39

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

NASA Astrophysics Data System (ADS)

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). Cause

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

2010-05-01

40

Analysing flow patterns in degraded peat soils using TiO2 dye  

NASA Astrophysics Data System (ADS)

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.

Liu, Haojie; Lennartz, Bernd

2014-05-01

41

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...

42

New Anaerobic, Ammonium-Oxidizing Community Enriched from Peat Soil? †  

PubMed Central

Anaerobic ammonium-oxidizing (anammox) bacteria have been recognized as an important sink for fixed nitrogen and are detected in many natural environments. However, their presence in terrestrial ecosystems has long been overlooked, and their contribution to the nitrogen cycling in natural and agricultural soils is currently unknown. Here we describe the enrichment and characterization of anammox bacteria from a nitrogen-loaded peat soil. After 8 months of incubation with the natural surface water of the sampling site and increasing ammonium and nitrite concentrations, anammox cells constituted 40 to 50% of the enrichment culture. The two dominant anammox phylotypes were affiliated with “Candidatus Jettenia asiatica” and “Candidatus Brocadia fulgida.” The enrichment culture converted NH4+ and NO2? to N2 with the previously reported stoichiometry (1:1.27) and had a maximum specific anaerobic ammonium oxidation rate of 0.94 mmol NH4+·g (dry weight)?1·h?1 at pH 7.1 and 32°C. The diagnostic anammox-specific lipids were detected at a concentration of 650 ng·g (dry weight)?1, and pentyl-[3]-ladderane was the most abundant ladderane lipid. PMID:21148690

Hu, Bao-lan; Rush, Darci; van der Biezen, Erwin; Zheng, Ping; van Mullekom, Mark; Schouten, Stefan; Sinninghe Damsté, Jaap S.; Smolders, Alfons J. P.; Jetten, Mike S. M.; Kartal, Boran

2011-01-01

43

Burkholderia eburnea sp. nov., isolated from peat soil.  

PubMed

A novel aerobic bacterium, designated strain RR11(T), was isolated from peat soil and was characterized by using a polyphasic taxonomic approach and identified in order to determine its taxonomic position. Strain RR11(T) is a Gram-negative, non-sporulating, motile, short-rod-shaped bacterium. 16S rRNA gene sequence analysis identified this strain as a member of the genus Burkholderia of the class Betaproteobacteria. The highest degrees of gene sequence similarity were found with Burkholderia tropica Ppe8(T) (98.0?%), B. bannensis E25(T) (97.3?%), B. ferrariae FeGI01(T) (97.1?%), B. unamae MTI-641(T) (97.1?%) and B. heleia SA41(T) (97.1?%). Strain RR11(T) had the following chemotaxonomic characteristics: the major ubiquinone was Q-8, the DNA G+C content was 60.8 mol%, the major fatty acids were C16?:?0, C19?:?0 cyclo ?8c and C17?:?0 cyclo and the polar lipid profile contained phosphatidylethanolamine, diphosphatidylglycerol, phosphatidylglycerol and an unknown aminophospholipid. Based on its morphological, physiological and chemotaxonomic characteristics, together with 16S rRNA gene sequence comparison results, strain RR11(T) represents a novel species, for which the name Burkholderia eburnea sp. nov. is proposed. The type strain is strain RR11(T) (?=?KEMC 7302-065(T)?=?JCM 18070(T)). PMID:24363296

Kang, Sang Rim; Srinivasan, Sathiyaraj; Lee, Sang Seob

2014-04-01

44

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...

45

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...

46

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

PubMed

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

Ojekanmi, A A; Chang, S X

2014-09-01

47

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

SciTech Connect

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.

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

2006-07-01

48

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

PubMed

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

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

2012-08-01

49

Gamma ray attenuation in the soils of Northern Ireland, with special reference to peat.  

PubMed

This study considers gamma ray attenuation in relation to the soils and bedrock of Northern Ireland using simple theory and data from a high resolution airborne survey. The bedrock is considered as a source of radiogenic material acting as parent to the soil. Attenuation in the near-surface is then controlled by water content in conjunction with the porosity and density of the soil cover. The Total Count radiometric data together with 1:250 k mapping of the soils and bedrock of Northern Ireland are used to perform statistical analyses emphasising the nature of the low count behaviour. Estimations of the bedrock response characteristics are improved by excluding areas covered by low count soils (organic/humic). Equally, estimations of soil response characteristics are improved by excluding areas underlain by low count bedrock (basalt). When the spatial characteristics of the soil-classified data are examined in detail, the low values form spatially-coherent zones (natural clusters) that can potentially be interpreted as areas of increased water content for each soil type. As predicted by theory, the highest attenuation factors are associated with the three organic soil types studied here. Peat, in particular, is remarkably skewed to low count behaviour in its radiometric response. Two detailed studies of blanket bogs reveal the extent to which peat may be mapped by its radiometric response while the intra-peat variations in the observed response may indicate areas of thin cover together with areas of increased water content. PMID:22858640

Beamish, David

2013-01-01

50

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

PubMed Central

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

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

2013-01-01

51

Impact of drainage on wettability of fen peat-moorsh soils  

NASA Astrophysics Data System (ADS)

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.

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

2009-04-01

52

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

PubMed Central

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 ?g 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

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

2013-01-01

53

Polycyclic aromatic hydrocarbons in background podzolic and gleyic peat-podzolic soils  

NASA Astrophysics Data System (ADS)

The qualitative and quantitative composition of polycyclic aromatic hydrocarbons (PAHs) has been determined in the background podzolic and gleyic peat-podzolic soils of the middle and northern taiga zones of northeastern Europe using the methods of highly efficient liquid chromatography and chromato-mass spectrometry. The distribution of polyarenes in the soil profiles follows the eluvial-illuvial pattern. Organic and illuvial horizons are the biogeochemical barriers for PAHs migrating in the soils. The revealed regularities of the accumulation and redistribution of PAHs in the soil profiles are in agreement with the character of the soil-forming processes in the northern and middle taiga zones.

Gabov, D. N.; Beznosikov, V. A.; Kondratenok, B. M.

2007-03-01

54

Continuous measurements of CO2 emission from cultivated peat soil - effect of tillage intensity  

NASA Astrophysics Data System (ADS)

Peatlands process and transfer significant quantities of greenhouse gases (GHG) such as CO2, CH4 and N2O. Most natural water-saturated peatlands sequester large amounts of CO2 from the atmosphere and emit CH4. Drainage and cultivation of peat soils increase soil aeration and reverse the carbon flux into net CO2 emissions, while CH4 emissions decrease and cultivated peat soils may even act as sinks for CH4. Fertile peat soils are potential sources of N2O when drained. In this investigation we used automatic dark chambers (ADC BioScientific Ltd) to measure CO2 emissions from plots with different soil tillage intensities. The field trial is located on the island Gotland east of the Swedish main land (57.584825N 18.47691E) and the soil is a peat soil with high pH (7.5) and organic content of 46.4 % (loss on ignition). The set-up was 4 treatments repeated in 4 blocks. Each plot was 18 by 25 meters and the following treatments were tested: A. Ploughing every year B. Ploughing 1 out of 4 years C. Only stubble cultivation D. Permanent ley One chamber was put in each plot and connected to a master control unit to create a network with 16 chambers. Measurements were made every hour during most of 2012 (17/4- 6/11 with some gaps) and every second hour during 2013 (22/4-27/6). Higher emissions could be observed just after cultivation and that effect lasted for about one day. The average emission was highest from treatment D during 2012 (4.53 ?mol m-2 s-1) and treatment C and D during 2013 (3.85 ?mol m-2 s-1).

Berglund, Örjan; Berglund, Kerstin

2014-05-01

55

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

NASA Astrophysics Data System (ADS)

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.

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

2010-05-01

56

Effects of soil improvement treatments on bacterial community structure and soil processes in an upland grassland soil.  

PubMed

Abstract Temporal temperature gradient electrophoresis (TTGE) analysis of 16S rRNA gene fragments amplified with primers selective for eubacteria and beta-proteobacterial ammonia-oxidising bacteria (AOB) was used to analyse changes in bacterial and AOB community profiles of an upland pasture following soil improvement treatments (addition of sewage sludge and/or lime). Community structure was compared with changes in activity assessed by laboratory measurements of basal respiration and ammonia oxidation potentials, and with measurements of treatment- and time-related changes in soil characteristics. The predominant bacterial populations had a high degree of similarity under all treatment regimens, which was most pronounced early in the growing season. Most of the differences that occurred between soil samples with time could be accounted for by spatial and temporal variation; however, analysis of variance and cluster analysis of similarities between 16S rDNA TTGE profiles indicated that soil improvement treatments exerted some effect on community structure. Lime application had the greatest influence. The impact of soil improvement treatments on autotrophic ammonia oxidation was significant and sustained, especially in soils which had received sewage sludge and lime treatments in combination. However, despite obvious changes in soil characteristics, e.g. pH and soil nitrogen, increasing heterogeneity in the AOB community structure over time obscured the treatment effects observed at the beginning of the experiment. Nevertheless, time series analysis of AOB TTGE profiles indicated that the AOB community in improved soils was more dynamic than in control soils where populations were found to be relatively stable. These observations suggest that the AOB populations exhibited a degree of functional redundancy. PMID:19719578

Gray, Neil D; Hastings, Richard C; Sheppard, Samuel K; Loughnane, Paul; Lloyd, David; McCarthy, Alan J; Head, Ian M

2003-10-01

57

Interannual, seasonal, and diel variation in soil respiration relative to ecosystem respiration at a wetland to upland slope at Harvard Forest  

Microsoft Academic Search

Soil carbon dioxide efflux (soil respiration, SR) was measured with eight autochambers at two locations along a wetland to upland slope at Harvard Forest over a 4 year period, 2003–2007. SR was consistently higher in the upland plots than at the wetland margin during the late summer\\/early fall. Seasonal and diel hystereses with respect to soil temperatures were of sufficient

Stephen C. Phillips; Ruth K. Varner; Steve Frolking; J. William Munger; Jill L. Bubier; Steven C. Wofsy; Patrick M. Crill

2010-01-01

58

Estimating soil moisture in gullies from adjacent upland measurements through different observation operators  

NASA Astrophysics Data System (ADS)

SummarySoil moisture datasets in large gullies are rare due to the difficulty of direct sampling in such landform. This study attempted to estimate spatial soil moisture averages in gullies from measurements of adjacent uplands by using observation operators, based on three-year soil moisture datasets in a gully catchment of the Loess Plateau. Soil moisture datasets in 2010 and 2011 were used for developing observation operators and those in 2012 were used for validation. Several nonlinear and linear methods including cumulative distribution function (CDF) matching method, linear regression (LRG) method, mean relative difference (MRD) method and linear rescaling (LRS) method were used to define observation operators. The results showed observation operators significantly improved the predictions compared to when using spatial averages of uplands as the direct surrogates for gullies. Among different methods, the CDF matching method performed best in estimating soil moisture in gullies followed by the LRG, LRS and MRD methods. Validation analysis showed that the linear observation operators such as LRS, MRD and LRG had better temporal transferability than the nonlinear operators. The MRD observation operators for various layers could successfully transfer in time whereas temporal transferability only succeeds to a limited extent for other observation operators. Furthermore, the MRD, LRG and LRS methods exhibited better vertical transferability than the CDF matching method. However, the transferability of observation operators across the whole root zone layers was not successful.

Gao, X.; Wu, P.; Zhao, X.; Zhou, X.; Zhang, B.; Shi, Y.; Wang, J.

2013-04-01

59

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

PubMed Central

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

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

2014-01-01

60

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

PubMed

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

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

2014-10-22

61

Shergottite Impact Melt Glasses Contain Soil from Martian Uplands  

NASA Technical Reports Server (NTRS)

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.

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

2002-01-01

62

Shergottite Impact Melt Glasses Contain Soil from Martian Uplands  

NASA Technical Reports Server (NTRS)

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. 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 meteoroid 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.

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

2002-01-01

63

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...

64

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...

65

Plant species from mesotrophic wetlands cause relatively high methane emissions from peat soil  

Microsoft Academic Search

Plants can influence methane emissions from wetland ecosystems by altering its production, consumption and transport in the\\u000a soil. The aim of this study was to investigate how eight vascular plant species from mesotrophic to eutrophic wetlands vary\\u000a in their influence on CH4 emissions from peat cores, under low and high N supply. Additionally, we measured the production of low-molecular-weight\\u000a organic

Albert Koelbener; Lena Ström; Peter J. Edwards; Harry Olde Venterink

2010-01-01

66

Complexes of the antimicrobial ciprofloxacin with soil, peat, and aquatic humic substances.  

PubMed

Natural organic matter (NOM) is implicated in the binding of antibiotics by particles in soils and waters. The authors' previous computational study revealed structural rearrangement of both hydrophilic and hydrophobic moieties of NOM to favor H-bonding and other intermolecular interactions, as well as both competition with ion-exchange reactions and bridging interactions by NOM-bound divalent cations. The importance of these interactions was investigated using fluorescence-quenching spectroscopy to study the adsorption of ciprofloxacin (Cipro), a fluoroquinolone antibiotic, on 4 reference humic substances (HSs): Elliott soil humic acid (HA), Pahokee peat HA, and Suwannee river HA and fulvic acid. A simple affinity spectrum HS model was developed to characterize the cation-exchange capacity and the amount of H-bond donor moieties as a function of pH. The adsorption results stress the influence of both pH conditions and the type of HS: both soil HA and peat HA exhibited up to 3 times higher sorption capacity than the aquatic HS at pH???6, normalizing to the aromatic C content accounted for the differences among the terrestrial HS, and increasing the concentration of divalent cations led to a decrease in adsorption on aquatic HA but not on soil HA. In addition, the pH-dependent speciation models of the Cipro-HS complexes illustrate an increase in complexation due to an increase in deprotonation of HS ligands with increasing pH and, at circumneutral and alkaline pH, enhanced complexation of zwitterionic Cipro only in the presence of soil HA and peat HA. The findings of the present study imply that, in addition to electrostatic interactions, van der Waals interactions as facilitated by aromatic structures and H-bond donating moieties in terrestrial HS may facilitate a favorable binding environment. Environ Toxicol Chem 2013;32:1467-1478. © 2013 SETAC. PMID:23456646

Aristilde, Ludmilla; Sposito, Garrison

2013-07-01

67

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

USGS Publications Warehouse

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.

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

2001-01-01

68

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

NASA Astrophysics Data System (ADS)

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.

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

2013-08-01

69

Mercury in vegetation and organic soil at an upland boreal forest site in Prince Albert National Park, Saskatchewan, Canada  

Microsoft Academic Search

We studied an upland boreal forest plot located in the Prince Albert National Park, Saskatchewan, Canada, to measure the total mercury content in vegetation and organic soil with a view to assessing the potential for mercury release during forest fires. The study area consists of two stands of vegetation regrown after fires 39 and 130 years ago, with different carbon

H. R. Friedli; L. F. Radke; N. J. Payne; D. J. McRae; T. J. Lynham; T. W. Blake

2007-01-01

70

Effect of soil stratification on the development and migration of headcuts in upland concentrated flows  

NASA Astrophysics Data System (ADS)

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 preformed step were subjected to identical simulated rainstorms and clear-water overland flow rates, which resulted in predictable, actively migrating headcut scour holes with nearly identical characteristics. When an erosion-resistant layer was incorporated into the packed soil bed at a depth that exceeded this expected plunge pool scour depth, the erosion and hydraulic processes of the migrating headcuts remained unchanged. When the erosion-resistant layer was placed so as to intersect this potential headcut scour depth, the erosivity of the reattached wall jet was unable to erode this layer, and the depth of scour, the nappe entry angle, and sediment efflux all were reduced inversely proportional to the relative depth of the resistant layer. These data were successfully predicted using modified jet impingement theory for headcut scour holes and demonstrate further the effects of soil management and tillage practices on total soil losses from agricultural fields.

Gordon, Lee M.; Bennett, Sean J.; Wells, Robert R.; Alonso, Carlos V.

2007-07-01

71

Changes in soil fungal:bacterial biomass ratios following reductions in the intensity of management of an upland grassland  

Microsoft Academic Search

In this study we examined the effect on soil fungal:bacterial biomass ratios of withholding fertiliser, lime, and sheep-grazing from reseeded upland grassland. The cessation of fertiliser applications on limed and grazed grassland resulted in a reduction in soil pH from 5.4 to 5.1. The cessation of fertiliser applications and liming on grazed grassland resulted in a fall in pH from

Richard D. Bardgett; Philip J. Hobbs; Åsa Frostegård

1996-01-01

72

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

SciTech Connect

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.

Riha, B

2005-10-31

73

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

NASA Astrophysics Data System (ADS)

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.

Comas, Xavier; Wright, William

2014-08-01

74

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

NASA Astrophysics Data System (ADS)

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.

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

2011-05-01

75

Assessing the probability of carbon and greenhouse gas benefit from the management of peat soils.  

PubMed

This study proposes a method for assessing the probability that land management interventions will lead to an improvement in the carbon sink represented by peat soils. The method is able to: combine studies of different carbon uptake and release pathways in order to assess changes on the overall carbon or greenhouse gas budget; calculate the probability of the management or restoration leading to an improvement in the budget; calculate the uncertainty in that probability estimate; estimate the equivalent number of complete budgets available from the combination of the literature; test the difference in the outcome of different land management interventions; and provide a method for updating the predicted probabilities as new studies become available. Using this methodology, this study considered the impact of: afforestation, managed burning, drainage, drain-blocking, grazing removal; and revegetation, on the carbon budget of peat soils in the UK. The study showed that afforestation, drain-blocking, revegetation, grazing removal and cessation of managed burning would bring a carbon benefit, whereas deforestation, managed burning and drainage would bring a disbenefit. The predicted probabilities of a benefit are often equivocal as each management type or restoration often leads to increase in uptake in one pathway while increasing losses in another. PMID:20427076

Worrall, F; Bell, M J; Bhogal, A

2010-06-01

76

Mercury in mushrooms and soil from the Wielu?ska Upland in south-central Poland.  

PubMed

Concentrations of mercury were determined in the fruiting bodies of 15 species of higher mushrooms and underlying soil substrate collected from Wielu?ska 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

Falandysz, Jerzy; Bielawski, Leszek; Kawano, Masabide; Brzostowski, Andrzej; Chudzy?ski, Krzysztof

2002-09-01

77

Thaumarchaeal ammonia oxidation in an acidic forest peat soil is not influenced by ammonium amendment.  

PubMed

Both bacteria and thaumarchaea contribute to ammonia oxidation, the first step in nitrification. The abundance of putative ammonia oxidizers is estimated by quantification of the functional gene amoA, which encodes ammonia monooxygenase subunit A. In soil, thaumarchaeal amoA genes often outnumber the equivalent bacterial genes. Ecophysiological studies indicate that thaumarchaeal ammonia oxidizers may have a selective advantage at low ammonia concentrations, with potential adaptation to soils in which mineralization is the major source of ammonia. To test this hypothesis, thaumarchaeal and bacterial ammonia oxidizers were investigated during nitrification in microcosms containing an organic, acidic forest peat soil (pH 4.1) with a low ammonium concentration but high potential for ammonia release during mineralization. Net nitrification rates were high but were not influenced by addition of ammonium. Bacterial amoA genes could not be detected, presumably because of low abundance of bacterial ammonia oxidizers. Phylogenetic analysis of thaumarchaeal 16S rRNA gene sequences indicated that dominant populations belonged to group 1.1c, 1.3, and "deep peat" lineages, while known amo-containing lineages (groups 1.1a and 1.1b) comprised only a small proportion of the total community. Growth of thaumarchaeal ammonia oxidizers was indicated by increased abundance of amoA genes during nitrification but was unaffected by addition of ammonium. Similarly, denaturing gradient gel electrophoresis analysis of amoA gene transcripts demonstrated small temporal changes in thaumarchaeal ammonia oxidizer communities but no effect of ammonium amendment. Thaumarchaea therefore appeared to dominate ammonia oxidation in this soil and oxidized ammonia arising from mineralization of organic matter rather than added inorganic nitrogen. PMID:20889787

Stopnisek, Nejc; Gubry-Rangin, Cécile; Höfferle, Spela; Nicol, Graeme W; Mandic-Mulec, Ines; Prosser, James I

2010-11-01

78

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

PubMed

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

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

2014-08-01

79

The influence of aeration and temperature on the structure of bacterial complexes in high-moor peat soil  

NASA Astrophysics Data System (ADS)

The number and taxonomic structure of the heterotrophic block of aerobic and facultative anaerobic bacteria were studied in monoliths from a high-moor peat (stored at room temperature and in a refrigerator) and in the peat horizons mixed in laboratory vessels. The monitoring lasted for a year. In the T0 horizon, spirilla predominated at room and low temperatures; in the T1 and T2 horizons, bacilli were the dominants. The continuous mixing of the peat layers increased the oxygen concentration and the peat decomposition; hence, the shares of actinomycetes and bacilli (bacteria of the hydrolytic complex) increased. In the peat studied, the bacilli were in the active state; i.e., vegetative cells predominated, whose amount ranged from 65 to 90%. The representatives of the main species of bacilli (the facultative anaerobic forms prevailed) hydrolyzed starch, pectin, and carboxymethylcellulose. Thus, precisely sporiferous bacteria can actively participate in the decomposition of plant polysaccharides in high-moor peat soils that are characterized by low temperatures and an oxygen deficit. The development of actinomycetes is inhibited by low temperatures; they can develop only under elevated temperature and better aeration.

Kukharenko, O. S.; Pavlova, N. S.; Dobrovol'Skaya, T. G.; Golovchenko, A. V.; Pochatkova, T. N.; Zenova, G. M.; Zvyagintsev, D. G.

2010-05-01

80

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...

81

Soil-to-soybean transfer of (99)Tc and its underground distribution in differently contaminated upland soils.  

PubMed

Pot experiments were performed in a greenhouse to investigate the soil-to-soybean transfer of (99)Tc in two different upland soils labeled with (99)TcO4(-) in two contrasting ways. One was to mix the soil with a (99)TcO4(-) solution 26 d before sowing (pre-sowing deposition: PSD), and the other was to apply the solution onto the soil surface 44 d after sowing (growing-period deposition: GPD). The soil-to-plant transfer was quantified with the transfer factor (TF, ratio of the plant concentration to the average of at-planting and at-harvest soil concentrations) or the aggregated transfer factor (TFag, ratio of the plant concentration to the deposition density). For both the depositions, the transfer of (99)Tc to aerial parts decreased in the order of leaf > stem > pod > seed. TF values (dimensionless) from the PSD were 0.22 and 0.27 (no statistically significant difference) for mature dry seeds in the respective soils, whereas a 600-fold higher value occurred for dry leaves. The post-harvest concentrations of the PSD (99)Tc in the top 20 cm soils as a whole were about half the initial concentrations. Around 25% of the total applied activity remained in the GPD soils after the harvest. The post-harvest depth profiles of the GPD (99)Tc in the two soils showed similar patterns of logarithmic activity decrease with increasing soil depths. Only 1.5-4.3% of the total applied activity was removed through the harvested biomass (seeds, pods and stems), and it was estimated that a great part of the total pant uptake returned to the soil through the fallen leaves. TFag values (m(2) kg(-1)) were about 2-4 times higher for the GPD than for the PSD. This finding and generally high root uptake of Tc may indicate that the use of empirical deposition time-dependent TFag data is particularly important for predicting the plant concentrations of Tc after its growing-period deposition. PMID:24556176

Choi, Yong-Ho; Lim, Kwang-Muk; Jun, In; Kim, Byung-Ho; Keum, Dong-Kwon; Kim, In-Gyu

2014-06-01

82

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

NASA Astrophysics Data System (ADS)

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 20°C. 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.

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

2013-12-01

83

Respiration of soil and ground vegetation of a peat bog in southern taiga under drought stress  

NASA Astrophysics Data System (ADS)

Respiration of peat and ground vegetation (mostly sphagnum mosses) was measured by CO2 analyser LI-6400 in late August 2002 in the peat bog (Central Forest Nature Reserve, 560N, 330E, Tver region, Russia). The whole summer 2002 in the region was characterized by hot and dry weather, thus obtained data correspond to the extreme drought stress. Measurements were carried out on the 16 stationary points along the transect crossing the mire along the altitude gradient and presenting the whole range of vegetation complexes diversity: margin lag with the spruce stand and eutrophic and mesotrophic conditions; typical oligotrophic lag with pine stand and dwarf shrubs, tall sedges mesotrophic lawn, not forested hummock-hollow complex, forested hummock-hollow complex, the dwarf pine communities of different structure and at last the type of minerotrophic margin with meadow vegetation. As a “zero-point” the spruce forest on the land was appointed as the measurement point. The transect under study is the object of the long-term observations on the ground vegetation and groundwater parameters, which were related to obtained respiration values. The measured mean values of ground respiration were 4.9, 6.8, 7.5, 4.8, 3.9 and 3.7 mkmol m-2s-1 for spruce stand (bare soil), paludified spruce stand, pine mire margin, dwarf pine communities oligotrophic and minerotrophic part of the mire, respectively. Within the open peat bog hummock-hollow complex significantly higher respiration was observed for hummocks comparatively to the hollows: 6.6 and 4.2 mkmol m-2s-1, correspondingly. Significant correlation of ground respiration to the groundwater level and temperature difference between peat and air was observed. The study was carried out within the framework of international project TCOS. The data on the spatial variation of dark respiration depending on the vegetation structure and groundwater regime is considered as a background for the further functional patterns for the virgin mire ecosystems of the Russian Plain.

Tatarinov, F.; Minaeva, T.; Kurbatova, Yu.; Rusanovitch, N.

2003-04-01

84

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)

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.

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

2015-01-01

85

[Effects of precipitation and soil moisture on N2O emissions from upland soils in Guizhou].  

PubMed

Soils of corn-rape seed rotation, soybean-winter wheat rotation and fallow land in Guizhou were representatively selected to study effects of precipitation and soil moisture on N2O emissions. Furthermore, DNDC model was used to assess the potential effects of variations in precipitation in future on N2O emissions from above lands. The results indicated that N2O emission pulses were obviously driven by rainfall and N2O fluxes were correlated positively with precipitation and soil moisture. The results from DNDC modeling showed that N2O fluxes from soils in summer and autumn would be correlated positively with precipitation, but N2O fluxes in winter and spring would slightly decrease with great change of precipitation. PMID:11962324

Xu, Wenbin; Liu, Guangshen; Liu, Weibing

2002-01-01

86

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

NASA Astrophysics Data System (ADS)

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.

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

2006-10-01

87

Isolation and characterization of nitrogen-fixing bacteria of the genus Azospirillum from the soil of a Sphagnum peat bog  

Microsoft Academic Search

he presence of nitrogen-fixing bacteria of the genus Azospirillum in the soils of acidic raised Sphagnum bogs is revealed for the first time. Three Azospirillum strains, B2, B21, and B22, were isolated as a component of methane-oxidizing enrichment cultures, whereas attempts to isolate\\u000a them directly from peat samples have failed. The results of comparative analysis of the nucleotide sequences of

E. V. Doroshenko; E. S. Boulygina; E. M. Spiridonova; T. P. Tourova; I. K. Kravchenko

2007-01-01

88

Decomposition activity of peat soils in geogenous mires in Sasakami, central Japan  

Microsoft Academic Search

Decomposition rates of peat and cellulose, and oxygen consumption rates were studied in three minerotrophic peat mires in Sasakami, central Japan. These mires had differences in topography, pedology and hydrology. Two dominant vegetation types in each mire, a Sphagnum palustre–S. cuspidatum community and a Rhynchospora fauriei community, were selected as the decomposition study sites. The objective of this study was

Akira Haraguchi; Chiaki Hasegawa; Akiko Hirayama; Hisaya Kojima

2003-01-01

89

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)

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.

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

2012-04-01

90

The effect of anaerobicity and temperature on N2 and N2O dynamics in forestry drained boreal peat soils  

NASA Astrophysics Data System (ADS)

Molecular nitrogen (N2) is the dominant end-product of microbial denitrification in soils; however, due to difficulties in measuring N2 exchange, the emissions of N2 from terrestrial ecosystems are largely unknown. In boreal peatland soils, the combination of high soil carbon and nitrogen contents, fluctuating water-table and high decomposition activity of the peat make these soils potentially large emitters of N gases via microbial denitrification processes. This motivated us to quantify the N2 and nitrous oxide (N2O) losses from boreal drained peat soils varying in fertility status. Soil samples were collected from two drained peatland forests: a nutrient-rich (Lettosuo) and a nutrient-poor (Kalevansuo) site, both located in the boreal zone of Southern Finland. N2 and N2O emissions from intact soil cores were measured using the helium gas flow soil core method. Two incubation experiments were conducted focusing on the effects of anaerobicity and temperature on N2 and N2O dynamics of the top-soil (experiment 1), and the effect of anaerobicity on N2 and N2O dynamics in the peat profile (experiment 2). Soil samples in experiment 1 were incubated under 1) cold (2° C) aerobic (20% O2, 80% He), 2) cold (2° C) anaerobic (0% O2, 100% He), and 3) warm (15° C) anaerobic conditions, while those in experiment 2 were incubated under 1) warm aerobic and 2) warm anaerobic conditions. Dynamics of N2 and N2O fluxes for each incubation condition were followed until fluxes stabilized. In general, the N2 and N2O fluxes in the nutrient-rich Lettosuo peat were higher and more variable than those at the nutrient-poor Kalevansuo peat. In the nutrient-rich Lettosuo, both the N2 and N2O emissions increased dramatically after the change from aerobic to anaerobic conditions, and again after the temperature rise from 2 to 15° C. This latter peak in emissions was followed by a switch from N2O production to N2O consumption and a simultaneous sharp decrease in N2 emissions. Although, the N2 and N2O fluxes in the nutrient-poor Kalevansuo peat were small and close to the detection limit, the change from the aerobic to anaerobic conditions induced significant N2O uptake, which was even more pronounced under warm anaerobic conditions. At the nutrient-rich Lettosuo, all the three soil layers (10-15 cm, 15-20 cm, 40-45 cm) were equally active in N2 and N2O production or consumption. Overall, N2 emissions from both sites always exceeded N2O emissions, and when the fluxes were positive and above their detection limits, the ratio of N2:N2O ranged between 1 and 180.

Pihlatie, Mari; Hongisto, Isto; Dannenmann, Michael; Georg, Willibald; Rainer, Gasche; Klaus, Butterbach-Bahl

2013-04-01

91

Influence of moisture on the vital activity of actinomycetes in a cultivated low-moor peat soil  

NASA Astrophysics Data System (ADS)

It was found that the actinomycetal complex of a cultivated low-moor peat soil is characterized by a high population density and diversity of actinomycetes; representatives of eleven genera were isolated from this soil: Streptomyces, Micromonospora, Actinomadura, Saccharopolyspora, Microbispora, Microtetraspora, Streptosporangium, Nocardioides, Saccharomonospora, Kibdelosporangium, and Thermomonospora. Some genera were isolated from the soil under all the studied levels of soil moisture. The so-called rare (rarely occurring) genera (Saccharomonospora, Kibdelosporangium, and Thermomonospora) were isolated upon the low level of soil moisture, which ensured an absence of competition from the more abundant actinomycetes. Spores of all the studied actinomycetes could germinate under the low moisture level (a w = 0.67). The level of moisture a w = 0.98 was found to be optimal for the development of the actinomycetes. The complete cycle of the development of all the actinomycetes up to spore formation occurring was only observed under the high moisture level (a w = 0.98).

Zenova, G. M.; Gryadunova, A. A.; Doroshenko, E. A.; Likhacheva, A. A.; Sudnitsyn, I. I.; Pochatkova, T. N.; Zvyagintsev, D. G.

2007-05-01

92

Stable Isotope Probing of Peat and Forest Floor Amendments  

NASA Astrophysics Data System (ADS)

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 ?13C 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.

Quideau, Sylvie; Béasse, Mark

2013-04-01

93

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

NASA Astrophysics Data System (ADS)

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.

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

2013-12-01

94

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

PubMed Central

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

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

2012-01-01

95

Method for determining the acid ameliorating capacity of plant residue compost, urban waste compost, farmyard manure, and peat applied to tropical soils  

Microsoft Academic Search

Plant residue compost, urban waste compost, farmyard manure, and peat can be used to ameliorate soil acidity. The diversity of these materials and their highly variable composition mean that their reliability in increasing the soil pH is uncertain because of lack of a method to test their acid ameliorating capacities. Incubation of a Spodosol from Sumatra, an Oxisol from Burundi

M. T. F. Wong; S. Nortcliff; R. S. Swift

1998-01-01

96

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...

97

Changes of soil and plant tissue selenium status in an upland grassland contaminated by selenium-rich agricultural drainage sediment after ten years transformed from a wetland habitat.  

PubMed

A field survey was conducted in 1989, 1994, and 1999 in order to monitor the soil and vegetation Se concentrations at the Kesterson upland grassland contaminated by Se-rich drainage sediment. The rate of Se dissipation estimated by the change of soil Se concentration, via volatilization, found to be about 1.1% per year. Soil water-extractable Se increased in 1994, but greatly reduced in 1999. The increase of soil Se concentration in the top 15 cm of soil at the fresh-soil fill sites indicates that the plants were able to effectively take up the soluble soil Se from the lower soil profile and to deposit it on the top of the field. This process may reduce the rate of leaching of soil Se. Overall, the concentration of soil water-soluble Se was relatively low and it is unlikely that problems of transport of Se from the Kesterson soil to the adjacent uncontaminated environment by leaching can occur. Plant tissue Se concentration was found to coincide with the soil water-extractable Se concentration. The average plant tissue Se concentration and soil water-extractable Se detected in 1999 was about 10 microg Se g(-1) and 110 microg Se kg(-1) dry weight, respectively, and the estimated bioaccumulation value of this upland grassland is less than 10% of the previous wetland habitat. Therefore, the existing Kesterson grassland should not be at high risk to the environment. PMID:11023699

Wu, L; Banuelos, G; Guo, X

2000-10-01

98

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)

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.

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

2014-05-01

99

[Dynamics of upland field P pool under a long-term application of fertilizer P in yellow soil area and their effects on P concentration in runoff].  

PubMed

Studies on the dynamics of upland field P pool under a long-term application of fertilizer P in yellow soil area and their effects on P concentration in runoff showed that the contents of A1-P, Fe-P and Ca-P in soil cultivated layer increased greatly, and Olsen-P and algae-available P also accumulated obviously. The correlation coefficients of algae-available P content in the high-P soils (Olsen-P > 25 mg.kg-1) with the quantities of A1-P, Fe-P and Ca-P were 0.859**, 0.903** and 0.650*, respectively, of which, Fe-P was the most important. By a 30-min rainfall simulation experiment with a constant rainfall rate of 63.2 mm.h-1, the concentrations of dissolved reactive P and bio-available P in runoff from low-P upland fields (Olsen-P 4.62-15.9 mg.kg-1) were 2.81-4.17 micrograms.L-1 and 0.723-0.876 mg.L-1, respectively, whereas their concentrations in runoff from high-P upland fields (Olsen-P 29.4-59.2 mg.kg-1) were 0.026-0.714 mg.L-1 and 0.996-1.281 mg.L-1, respectively. Therefore, runoff from high-P upland fields could accelerate water eutrophication. PMID:12827870

Liu, Fang; Huang, Changyong; He, Tengbin; Qian, Xiaogang; Liu, Yuansheng; Luo, Haibo

2003-02-01

100

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...

101

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

NASA Astrophysics Data System (ADS)

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.

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

2012-12-01

102

Peat Processing  

NASA Technical Reports Server (NTRS)

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.

1986-01-01

103

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

USGS Publications Warehouse

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.

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

1982-01-01

104

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

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.

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

2005-01-01

105

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

NASA Astrophysics Data System (ADS)

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.

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

2010-05-01

106

An easily installable groundwater lysimeter to determine water balance components and hydraulic properties of peat soils Hydrology and Earth System Sciences, 7(1), 2332 (2003) EGU  

E-print Network

installable groundwater lysimeter to determine water balance components and hydraulic properties of peat soils. Moreover, they should allow the in situ determination of the hydraulic properties (water retentionAn easily installable groundwater lysimeter to determine water balance components and hydraulic

Boyer, Edmond

107

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

PubMed Central

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

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

2014-01-01

108

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

NASA Astrophysics Data System (ADS)

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.

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

2009-04-01

109

Degrading uplands in the rainforest region of Madagascar: Fallow biomass, nutrient stocks, and soil nutrient availability  

Microsoft Academic Search

Soil fertility restoration depends on natural fallows in the slash-and-burn system of eastern Madagascar. In the Beforona-Vohidrazana\\u000a study zone, none of the fallow species are able to withstand the slashing, burning and cropping frequencies of 3–5 years.\\u000a Eventually soils are abandoned for agriculture. Along the degradation sequence, this study quantifies fallow biomass, nutrient\\u000a stocks and soil nutrient availability of four dominant

Erika Styger; Erick C. M. Fernandes; Harivelo M. Rakotondramasy; Eric Rajaobelinirina

2009-01-01

110

On the applicability of unimodal and bimodal van Genuchten-Mualem based models to peat and other organic soils under evaporation conditions  

NASA Astrophysics Data System (ADS)

Soil moisture is one of the key parameters controlling biogeochemical processes in peat and other organic soils. To understand and accurately model soil moisture dynamics and peatland hydrological functioning in general, knowledge about soil hydraulic properties is crucial. As peat differs in several aspects from mineral soils, the applicability of standard hydraulic functions (e.g. van Genuchten-Mualem model) developed for mineral soils to peat soil moisture dynamics might be questionable. In this study, the hydraulic properties of five types of peat and other organic soils from different German peatlands have been investigated by laboratory evaporation experiments. Soil hydraulic parameters of the commonly-applied van Genuchten-Mualem model and the bimodal model by Durner (1994) were inversely estimated using HYDRUS-1D and global optimization. The objective function included measured pressure heads and cumulative evaporation. The performance of eight model set-ups differing in the degree of complexity and the choice of fitting parameters were evaluated. Depending on the model set-up, botanical origin and degree of peat decomposition, the quality of the model results differed strongly. We show that fitted ‘tortuosity’ parameters ? of the van Genuchten-Mualem model can deviate very much from the default value of 0.5 that is frequently applied to mineral soils. Results indicate a rather small decrease of the hydraulic conductivity with increasing suction compared to mineral soils. Optimizing ? did therefore strongly reduce the model error at dry conditions when high pressure head gradients occurred. As strongly negative pressure heads in the investigated peatlands rarely occur, we also reduced the range of pressure heads in the inversion to a ‘wet range’ from 0 to -200 cm. For the ‘wet range’ model performance was highly dependent on the inclusion of macropores. Here, fitting only the macropore fraction of the bimodal model as immediately drainable additional pore space seems to be a practical approach to account for the macropore effect, as the fitting of the full bimodal model led to only marginal further improvement of model performance. This keeps the number of parameters low and thus provides a model that is more easily managed in pedotransfer function development and practical applications like large scale simulations. Our findings point out first options to improve the performance of the frequently-used simple single-domain models when they are applied to organic soils. We suggest further performance evaluation of these models during wetting periods when they are known to fail to describe preferential and non-equilibrium flow phenomena.

Dettmann, Ullrich; Bechtold, Michel; Frahm, Enrico; Tiemeyer, Bärbel

2014-07-01

111

Pedo-hydrological and sediment responses to simulated rainfall on soils of the Konya uplands (Turkey)  

Microsoft Academic Search

Microplot experiments using a portable rainfall simulator were carried out in April 1992 on 15 Turkish soils with textures ranging from clay loam to loamy clay and slopes from 3° to 12°. In order to determine the effects of a change in land use on infiltration and erosion, pairs of sites with soils developed on identical parent material were chosen.

P. Böhm; G. Gerold

1995-01-01

112

Geobotanical indication of the trophic status and moistening of reclaimed oil-polluted oligotrophic peat soils in the middle reaches of the Ob River  

NASA Astrophysics Data System (ADS)

Changes in the trophic status and moistening of oligotrophic peat soils subjected to oil pollution and subsequent reclamation in the middle reaches of the Ob River are discussed. The main plants-indicators are listed. Numerical estimates of the trophic level and the degree of moistening of natural and transformed soils of the widespread bog biogeocenoses—pine-dwarf-shrub-sphagnum, complex ridged-hollow, and cotton grass-sphagnum bogs—are suggested on the basis of the ecological scales developed by L.G. Ramenskii. These estimates have been grouped into several classes used to describe the ecological conditions in natural biogeocenoses of the middle taiga subzone. The main tendencies in the transformation of ecological conditions are revealed. Indicative characteristics of the anthropogenic salinization of peat soils are established.

Avetov, N. A.

2009-01-01

113

Soils of cryogenic subarid steppe landscapes in the Terekhol intermontane Depression of the Sangilen Upland  

NASA Astrophysics Data System (ADS)

The soil cover of the Terekhol intermontane Depression in the Tyva Region is poorly studied. The data obtained in the 1950s do not reflect the real genetic diversity of soils and their specific character. According to these data, the soil cover was dominated by meadow-chernozemic soils under virgin steppe-like meadows. The investigations of 2007-2009 show that the disperse-carbonate chernozems, which are often solonetzic and weakly saline; the specific polygenetic dark soda solonchaks-solonetzes; and the postagrogenic chernozems, solonetzes, and agrozems are the main components of the soil cover of the depression at the present time. The described chernozems correspond mainly to the central image of southern Siberia chernozems. The investigated solonetzes are characterized by a number of evolution-genetic features that distinguish them from previously described solonetzes of Tyva and from all the solonetzic soils in the current interpretation. The chernozems and solonetzes have cryogenic features due to the cold extremely continental climate and relatively shallow continuous permafrost.

Bronnikova, M. A.; Turova, I. V.; Kuznetsova, E. P.; Kozlov, D. N.; Khokhlova, O. S.

2011-06-01

114

Is soil degradation unrelated to deforestation? Examining soil parameters of land use systems in upland Central Sulawesi, Indonesia  

Microsoft Academic Search

It is generally assumed that declining soil fertility during cultivation forces farmers to clear forest. We wanted to test this for a rainforest margin area in Central Sulawesi, Indonesia. We compared soil characteristics in different land-use systems and after different length of cultivation. 66 sites with four major land-use systems (maize, agroforestry, forest fallow and natural forest) were sampled. Soils

Georg Dechert; Edzo Veldkamp; Iswandi Anas

2004-01-01

115

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

PubMed

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?gkg(-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

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

2015-04-01

116

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

NASA Astrophysics Data System (ADS)

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.

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

2013-11-01

117

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

USGS Publications Warehouse

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.

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

118

The impact of sludge amendment on methanogen community structure in an upland soil  

Microsoft Academic Search

In the EU, municipal sewage sludge application to agricultural land has increased dramatically since the ban on dumping at sea came into effect in 1998. There are many concerns related to potential contamination and reduction in plant productivity. In this study, the aim was to assess the impact of repeated long-term soil amendment with anaerobically digested sewage sludge on methanogen

S. K. Sheppard; A. J. McCarthy; J. P. Loughnane; N. D. Gray; I. M. Head; D. Lloyd

2005-01-01

119

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

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.

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

1998-01-01

120

The peats of Costa Rica  

SciTech Connect

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.

Obando A, L.; Malavassi R, L.; Ramirez E, O. (RECOPE, San Jose (Costa Rica)); Cohen, A. (South Carolina Univ., Columbia, SC (USA). Dept. of Geological Sciences); Raymond, R. Jr.; Thayer, G.R. (Los Alamos National Lab., NM (USA))

1991-04-01

121

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

SciTech Connect

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.

Galbraith, H.; LeJeune, K.; Lipton, J. [Hagler Bailly Consulting, Inc., Boulder, CO (United States)

1995-11-01

122

The effects of ecological restoration, on soil-pore water quality and DOC concentrations, on a British upland blanket bog.  

NASA Astrophysics Data System (ADS)

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.

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

2013-04-01

123

The Severity of Smouldering Peat Fires and Damage to the Forest Soil   

E-print Network

Smouldering wildfires propagate slowly through surface and subsurface organic layers of the forest ground and severely affect the soil, producing physical, chemical and biological changes. These effects are caused by the prolonged heating...

Rein, Guillermo; Cleaver, Natalie; Ashton, Clare; Pironi, Paolo; Torero, Jose L

124

Mycobiota of peat-gleyic soils during the process of recultivation  

NASA Astrophysics Data System (ADS)

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.

Ibatullina, I.; Khabibullina, F.

2009-04-01

125

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

NASA Astrophysics Data System (ADS)

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.

Bernardi, Tony

2014-05-01

126

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 Sacramento–San 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...

127

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

NASA Astrophysics Data System (ADS)

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.

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

128

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

NASA Astrophysics Data System (ADS)

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.

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

2014-05-01

129

What are the mechanisms controlling carbon flux from peat soils across slopes?  

NASA Astrophysics Data System (ADS)

Peatlands are a globally important terrestrial carbon stock but carbon budget models need further improvement. The use of empirical observations to increase the accuracy of process based models has helped to constrain the error involved in accounting for peatland carbon balances, yet our understanding of peatland function needs to improve still further. Hydrology and topography are important controls on the carbon balance of peatlands. The hydrology of hillslopes has been studied, with runoff mechanisms and flow pathways dependent upon the topographic position. Topslope plateau areas have been observed to promote a large degree of surface runoff, acting as a shedding area delivering water downslope. Midslopes may experience fewer saturation runoff events due to the greater hydraulic gradient, with lower water tables likely to cause subsurface throughflow that is delivered downslope at the accumulation area at the bottom of the slope. This can help to maintain higher water tables at the foot of the slope and attenuate saturation runoff events (Holden and Burt 2003). The different hydrological mechanisms studied across the hillslope have not until recently been studied in the context of carbon cycling as well. The author has presented results elsewhere on the role that hillslope position has on carbon flux, finding that with water table drawdown observed on the midslopes, there is a concurrent increase in the rates of ecosystem respiration dependent upon the changing depth of the water table. There is also a decrease in the concentration of dissolved organic carbon concentration downslope. This poster presents preliminary results looking to constrain the explanations for the changing levels of respiration and dissolved organic carbon content across the slope. One metre deep soil cores were taken from an intact and an eroded hillslope in the Peak District, UK, across four hillslope positions: topslope, upper midslope, lower midslope and bottomslope. The cores were analysed for bulk density, energy content using bomb calorimetry and CHNO to assess if the composition and structure of the soil substrate could explain observed changes across the slope in dissolved organic carbon content.

Boothroyd, I.; Worrall, F.; Allott, T.

2012-04-01

130

Low-cost removal of trace metals from copper-nickel mine stockpile drainage. Volume II - Trace metal sequestration by peat, other organics, tailings, and soils  

SciTech Connect

This report describes a two-phase experimental program to examine the feasibility of removing trace metals (Cu, Mi, Co, Zn) from stockpile effluent using readily available materials in low-cost, low-maintenance systems. Volume II is a literature review of several low-cost materials that might be used for removing trace metals from stockpile drainage. The materials included peat, humic acid, fulvic acid, other organics, soils, and tailings. The methods employed in the investigations review ranged from laboratory experiments to field-scale studies. Trace metal removal mechanisms and capacities were addressed.

Lapakko, K.A.; Strudell, J.D.; Eger, A.P.

1986-01-01

131

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)

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.

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

2012-12-01

132

Altitude or slope position - gaseous carbon cycling on UK blanket peat bogs  

Microsoft Academic Search

Blanket peat accounts for 87% of Britain's total peatlands and represents one of the UK's largest terrestrial carbon stores. For peatlands to accumulate carbon the net ecosystem exchange of CO2 (NEE) must be negative with respect to the atmosphere. Unlike many other peatlands, upland blanket peat bogs in the UK are draped across hillsides and so it could be that

Simon Dixon; James Rowson; Fred Worrall

2010-01-01

133

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

NASA Astrophysics Data System (ADS)

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.

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

134

Long-term stability of permafrost in subarctic peat plateaus, west-central Canada  

Microsoft Academic Search

Long-term vegetation succession and permafrost dynamics in subarctic peat plateaus of west-central Canada have been studied through detailed plant macrofossil analysis and extensive AMS radiocarbon dating of two peat profiles. Peatland inception at these sites occurred around 5800–5100 yr BP (6600–5900 cal. BP) as a result of paludification of upland forests. At the northern peat plateau site, located in the

A. Britta K. Sannel; Peter Kuhry

2008-01-01

135

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...

136

Biomass on Peat Soils?  

Microsoft Academic Search

\\u000a Energy security has become a priority as the world’s population increases and its standard of living improves, thus increasing\\u000a energy consumption. As the demand for energy increases, there is growing concern about the possible exhaustion of finite supplies\\u000a of fossil fuels in the not-too-distant future. In addition to the problem of availability, combustion of fossil fuels also\\u000a has negative environmental

Tom Kuhlman; René Verburg; Janneke van Dijk; Nga Phan-Drost

137

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)

Due to the UNFCCC report requirements of each country on the emissions of greenhouse gases from key sources the joint research project "Organic Soils" was established in Germany. The project's objective is to improve the data set on greenhousegas emissions from organic soils in Germany. Within 12 German Project Catchments emissions from different types of organic soils, e.g. under different land uses and hydrological conditions, are measured. At the location "Großes Moor" near Gifhorn (Lower Saxony) the effects of small-scale soil organic carbon and groundwater level gradients on the GHG fluxes (CO2, CH4 and N2O) are quantified. The study area is located within a former peat bog altered by drainage and peat cutting, which is currently grassland under extensive agricultural use. The focus of the study is on the acquisition of CO2, CH4 and N2O fluxes on six sites via manual closed chambers. In order to calculate the annual CO2 exchange rate, 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 10°C 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.

Leiber-Sauheitl, K.; Fuß, R.; Freibauer, A.

2012-04-01

138

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

PubMed

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

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

2008-08-01

139

Volcanic soil formation in Calabria (southern Italy): The Cecita Lake geosol in the late Quaternary geomorphological evolution of the Sila uplands  

NASA Astrophysics Data System (ADS)

This paper focuses on the main morphological, physical, chemical and mineralogical features of an andic-like soil, widely outcropping in the Sila upland plateau of Calabria (southern Italy), and its potential role in tephrostratigraphy. A multidisciplinary and multiscale approach allowed identification of this soil as a "masked" distal archive of volcanic products, developed on granite rocks and sediments with a coeval pyroclastic input during pedogenesis. The study demonstrates that the contribution of volcanic parent materials can be successfully hypothesized and assessed even in the absence, limited extent or poor preservation of primary eruptive products. The soil has an Andisol-like appearance, despite laboratory data that do not match the entire suite of diagnostic criteria for the Andisol taxonomic order. Geomorphological, stratigraphic and pedologic results, coupled with tephrostratigraphic and radiometric data, concur to suggest a Late Pleistocene(?) to Holocene age of the Andisol-like soil. In particular, the rhyolitic chemical composition of small-sized glass fragments (identified by SEM-EDS analyses) indicates soil genesis contributed by volcanic ash, probably sourced from Aeolian Arc explosive activity spanning the last 30 ka. Accordingly, the evidence of limited relict clay illuviation and the specific type of pedogenesis allowing the development of andic properties (in turn related to the neoformation of clay minerals from the weathering of volcanic glass) are consistent with a climatic shift from a seasonally-contrasted to a constantly humid pedoenvironment. This change can be ascribed to the Lateglacial(?) or Early-Middle Holocene to Late Holocene transition. Calibrated AMS 14C dates performed on charcoal fragments sampled from three representative soil profiles, provide Late Holocene ages (3136 ± 19, 343 ± 16 and 92 ± 24 yr BP), in accord with archaeological finds. On the basis of the consistent stratigraphic position, lateral continuity and wide extent, the soil can be considered a good pedostratigraphic marker in the Sila highlands and is informally defined as the "Cecita Lake geosol". It supplies valuable time constraints for the underlying (occasionally overlying) deposits and/or soils. Moreover, it allows regional-scale morphostratigraphic correlations and detailed reconstruction of Late Pleistocene-Holocene geomorphic events in Calabria, a very suitable region for distal tephra deposition in the central Mediterranean peri-volcanic area. The effects of high-energy volcanic eruptions are interfingered with or superimposed by other geomorphic processes and climatic or anthropogenic signals.

Scarciglia, Fabio; De Rosa, Rosanna; Vecchio, Giuseppe; Apollaro, Carmine; Robustelli, Gaetano; Terrasi, Filippo

2008-10-01

140

Properties and structure of raised bog peat humic acids  

NASA Astrophysics Data System (ADS)

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.

Klavins, Maris; Purmalis, Oskars

2013-10-01

141

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

NASA Astrophysics Data System (ADS)

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.

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

2010-01-01

142

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  

Microsoft Academic Search

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

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

2005-01-01

143

Will blocking historical drainage ditches increase carbon sequestration in upland blanket mires of Southwest England?  

NASA Astrophysics Data System (ADS)

Peat soils in the United Kingdom are estimated to store a minimum of 3,121Mt C (Lindsay, 2010). Despite being such a large carbon store the annual imbalance between uptake and release is small and susceptible to change in response to land management, atmospheric deposition and climate change. The upland blanket mires of Southwest England have been subject to extensive drainage and are particularly vulnerable to climate change as they lie at the lower edge of the peatland climatic envelope. The Mires-on-the-Moors project, funded by South West Water will restore over 2000 hectares of drained mire by April 2015. Herein, we question whether this restoration, which will block historical drainage ditches will allow the blanket bogs of Exmoor and Dartmoor National Parks to recover their ecohydrological functionality. We hypothesise that such mire restoration will increase the resilience of these ecosystems to climate change and will return these upland mires to peat forming/carbon sequestering systems. A method is proposed which aims to understand the processes driving gaseous carbon exchange and peat formation in an upland blanket bog and quantifies the effect restoration has on these processes. We propose to measure the spatial variation in gas fluxes with respect to structural features of the mire; drainage ditches and nanotopes. The role of vegetation; the community composition, phenology and health will be explored as well as environmental variables such as water table depths, temperature and photosynthetically active radiation. Importantly, the experiment will partition below ground respiration to assess the environmental controls and effect of restoration on autotrophic and heterotrophic respiration separately. Unusually, it will be possible to collect both pre- and post-restoration data for two experimental sites with existing intensive hydrological monitoring (baseline monitoring of water table depths at 15 minute timesteps has been in place for > 1 year at ca. 160 locations across two experimental catchments on Exmoor). Remote sensing of vegetation structure (using both airborne LiDAR and ground-based laser scanning tools) alongside geospatial modelling will enable the effects of restoration on carbon storage to be modelled from headwater catchment to moorland scales. Lindsay, R. (2010) Peatbogs and Carbon: A Critical Synthesis. University of East London, London.

Le Feuvre, N.; Hartley, I.; Anderson, K.; Luscombe, D.; Grand-Clement, E.; Smith, D.; Brazier, R.

2012-04-01

144

Effects of thermo-erosional disturbance on surface soil carbon and nitrogen dynamics in upland arctic tundra  

NASA Astrophysics Data System (ADS)

Thaw of ice-rich permafrost soils on sloping terrain can trigger erosional disturbance events that displace large volumes of soil and sediment, kill and damage plants, and initiate secondary succession. We examined how retrogressive thaw slumps (RTS), a common form of thermo-erosional disturbance in arctic tundra, affected the local loss and re-accumulation of carbon (C) and nitrogen (N) pools in organic and surface mineral soil horizons of 18 slumps within six spatially independent sites in arctic Alaska. RTS displaced 3 kg C and 0.2 kg N per m2 from the soil organic horizon but did not alter pools of C and N in the top 15 cm of the mineral horizon. Surface soil C pools re-accumulated rapidly (32 ± 10 g C m-2 yr-1) through the first 60 years of succession, reaching levels similar to undisturbed tundra 40-64 years after disturbance. Average N re-accumulation rates (2.2 ± 1.1 g N m-2 yr-1) were much higher than expected from atmospheric deposition and biological N fixation. Finally, plant community dominance shifted from graminoids to tall deciduous shrubs, which are likely to promote higher primary productivity, biomass accumulation, and rates of nutrient cycling.

Pizano, Camila; Barón, Andrés F.; Schuur, Edward A. G.; Crummer, Kathryn G.; Mack, Michelle C.

2014-07-01

145

Flux and turnover of fixed carbon in soil microbial biomass of limed and unlimed plots of an upland grassland ecosystem.  

PubMed

The influence of liming on rhizosphere microbial biomass C and incorporation of root exudates was studied in the field by in situ pulse labelling of temperate grassland vegetation with (13)CO(2) for a 3-day period. In plots that had been limed (CaCO(3) amended) annually for 3 years, incorporation into shoots and roots was, respectively, greater and lower than in unlimed plots. Analysis of chloroform-labile C demonstrated lower levels of (13)C incorporation into microbial biomass in limed soils compared to unlimed soils. The turnover of the recently assimilated (13)C compounds was faster in microbial biomass from limed than that from unlimed soils, suggesting that liming increases incorporation by microbial communities of root exudates. An exponential decay model of (13)C in total microbial biomass in limed soils indicated that the half-life of the tracer within this carbon pool was 4.7 days. Results are presented and discussed in relation to the absolute values of (13)C fixed and allocated within the plant-soil system. PMID:15816931

Rangel-Castro, J Ignacio; Prosser, Jim I; Ostle, Nick; Scrimgeour, Charlie M; Killham, Ken; Meharg, Andy A

2005-04-01

146

Chemical properties of peat used in balneology  

NASA Astrophysics Data System (ADS)

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

Szajdak, L.; H?ado?, T.

2009-04-01

147

Inorganic contents of peats  

SciTech Connect

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.

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

1988-02-01

148

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

NASA Astrophysics Data System (ADS)

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.

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

2013-04-01

149

Geomorphic, sedimentary, and potential palaeoenvironmental significance of peat blocks in alluvial river systems  

NASA Astrophysics Data System (ADS)

Fluvial erosion of peat deposits occurs in many environmental settings; however, the erosion and transport of large peat blocks by river channels has received relatively little attention. This paper describes the sedimentary significance and potential palaeoenvironmental interpretation of peat blocks in alluvial river systems. Evidence is presented from a number of field studies of upland river systems in northern England that illustrate a range of peat block forms and sedimentary features that are briefly compared with examples of peat blocks preserved in gravel stratigraphy. We show that peat blocks are an important geomorphological and sedimentological component of upland rivers draining eroding peatland catchments. They are of widespread occurrence and contribute significantly to river channel roughness and channel sedimentation. A variety of common sedimentary features can be observed including, shadow, crescent, perched, armoured, drape, embedded (part buried), cluster, and step forms. Peat blocks tend to be deposited on channel margins and bar tops and can be used as “maximum” stage indicator for major floods. The role of peat blocks in controlling sedimentation varies with channel width. In narrow channels where the size of the peat block approximates the channel width, blocks become jammed in the channel and exert a primary control on channel sedimentation. In wider channels, blocks tend to occur in isolation or in small clusters and are of only secondary importance in controlling sedimentation. Residence times of peat blocks varies from short periods of temporary deposition (days to months) to much longer timescales (months to years) with some blocks becoming permanently incorporated into the sedimentary record. The sedimentary characteristics of contemporary buried peat blocks have much in common with blocks preserved in alluvial gravel stratigraphy. This offers the potential for using these features for palaeoenvironmental reconstruction. Peat blocks in many ways are analogous to other low density geological materials (ice blocks, woody debris, and some volcanic sediments), and recognising the special sedimentological characteristics of this suite of materials is important as they are not always adequately characterised using conventional hydraulic relationships.

Warburton, Jeff; Evans, Martin

2011-07-01

150

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

NASA Astrophysics Data System (ADS)

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.

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

2014-05-01

151

[Variation characteristics of maize yield and fertilizer utilization rate on an upland yellow soil under long term fertilization].  

PubMed

An analysis was made on the 16-year experimental data from the long term fertilization, experiment of maize on a yellow soil in Guizhou of Southwest China. Four treatments, i. e. , no fertilization (CK), chemical fertilization (165 kg N x hm(-2), 82.5 kg P2O5 x hm(-2), and 82.5 kg K2O x hm(-2), NPK), organic manure (30555 kg x hm(-2), M), and combined applicatioin of chemical fertilizers and organic manure (NPKM), were selected to analyze the variation trends of maize yield and fertilizer use efficiency on yellow soil under effects of different long term fertilization modes, aimed to provide references for evaluating and establishing long term fertilization mode and promote the sustainable development of crop production. Overall, the maize yield under long term fertilization had an increasing trend, with a large annual variation. Treatment NPKM had the best yield-increasing effect, with the maize yield increased by 4075.71 kg x hm(-2) and the increment being up to 139.2%. Long term fertilization increased the fertilizer utilization efficiency of maize. In treatment M, the nitrogen and phosphorus utilization rates were increased significantly by 35.4% and 18.8%, respectively. Treatment NPK had obvious effect in improving potassium utilization rate, with an increment of 20% and being far higher than that in treatments M (8.7%) and NPKM (9.2%). The results showed that long term fertilization, especially the combined application of chemical fertilizers and organic manure, was of great importance in increasing crop yield and fertilizer use efficiency. PMID:24483072

Luo, Long-Zao; Li, Yu; Zhang, Wen-An; Xiao, Hou-Jun; Jiang, Tai-Ming

2013-10-01

152

CO2 Efflux from Cleared Mangrove Peat  

PubMed Central

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

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

2011-01-01

153

Cylindrical Piezometer Responses in a Humified Fen Peat  

Microsoft Academic Search

Most studies of peat hydrology have concentrated on processes below the watertable where pore water pressures and hydraulic conductivity are mea- sured using piezometers. While piezometer head recovery tests in poorly humified bog peats give responses similar to those expected from rigid soils, a number of studies have suggested that matrix compressibility might be impor- tant in affecting head recovery

Andrew J. Baird; Simon W. Gaffney

1994-01-01

154

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)

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.

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

2013-11-01

155

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.  

PubMed

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 NO(3)(-)-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 rho=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 (r(2)=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. PMID:19349066

Gabriel, Mark C; Kolka, Randy; Wickman, Trent; Nater, Ed; Woodruff, Laurel

2009-06-15

156

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

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.

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

2009-01-01

157

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

E-print Network

of eastern Upper Michigan, USA Randall J. Schaetzl a,, Walter L. Loope b,1 a Department of Geography, 128 Geography Building, Michigan State University, East Lansing, MI 48824-1117, USA b U.S. Geological Survey, P uplands in the eastern Upper Peninsula of Michigan. Previous research on this deposit, which we

Schaetzl, Randall

158

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

SciTech Connect

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.

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

1982-01-01

159

Peat, horticulture and environment  

Microsoft Academic Search

Peat-based growing media underpin the horticultural industry in the UK, although production sites cover less than 0.5% of the total peatland area. In recent years Peat Producer's Association members have released over 20% of their holdings to English Nature, representing virtually all the areas of current conservation value. The Association is now engaged in the assessment and development of restoration

R. A. Robertson

1993-01-01

160

Peat biogasification development program  

NASA Astrophysics Data System (ADS)

The design and operation of a peat anaerobic digestion process development unit is considered. Five areas are addressed: pretreatment information; anaerobic digestion; evaluation of waste streams; process model development and economic analysis; and planning for the process development unit. Data were taken for the development of the predictive process model. A number of batch and continuous pretreatment experiments were completed and analyzed. The four samples analyzed through solvent extration were completed, and the results are presented. Work on high pressure liquid chromatography continued, and the development of the gradient elution solvent system was completed with encouraging results. Pretreated peat was batch fermented; the continuously oxidized peat show conversions of close to 30 percent. This is significantly higher than the conversion for the batch oxidized peat. A predictive process model for the three phases of peat biogasification, solubilization, oxidation, and fermentation was developed.

Wise, D. L.

1981-01-01

161

Oxidative ratio (OR) of UK peats  

NASA Astrophysics Data System (ADS)

The oxidative ratio (OR) is the amount of CO2 sequestered in the terrestrial biosphere for each mol of O2 produced. The OR governs the effectiveness of a terrestrial biome to mitigate the impact of anthropogenic CO2 emissions and it has been used to calculate the balance of terrestrial and oceanic carbon sinks across the globe. However, few studies have investigated the controls of the variability in OR. What factors affect OR - climate? Soil type? Vegetation type? N deposition? Land use? Land use change? Small shifts in OR could have important implications in the global partitioning of CO2 between the atmosphere, biosphere, and oceans. This study looks at peat soils (Histosols) from a series of sites representing a climatic transect across the UK. Duplicate peat cores were taken, along with samples of above-ground vegetation and litter, from sites in northern Scotland (Forsinard), southern Scotland (Auchencorth), northern England (Moor House; Thorne Moor) through the Welsh borders (Whixhall Moss) and Somerset levels (Westhay Moor) to Dartmoor and Bodmin Moor in the south west of England. Sub-samples of the cores were analysed for their CHNO concentrations using a Costech ECS 4010 Elemental combustion system. Using the method of Masiello et al. (2008), OR values could be calculated from these elemental concentrations. Initial results show that OR values of UK peats varied between 0.94 and 1.1 with a median value of 1.05 which similar to the median value of World soils but the range is at the more reduced end. There was significant variation between peat cores, even between peat cores on the same site and the peat showed significant reduction in OR with depth in the core.

Clay, G. D.; Worrall, F.; Masiello, C. A.

2012-04-01

162

Sulfur mobility in peat  

Microsoft Academic Search

Lead-210 chronologies, vertical S concentration gradients and ?34S values are presented for 5 Sphagnum-dominated peat bogs located in Central Europe (Rybarenska slat and Ocean Bog; Czech Republic) and the British Isles (Thorne Moors, England; Connemara, Ireland; and Mull, Scotland). Sulfur concentrations were measured in three 40-cm deep peat cores per site, sectioned into 2-cm segments. The coefficient of variation in

Martin Novák; Marie Adamová; R. Kelman Wieder; Simon H. Bottrell

2005-01-01

163

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

PubMed

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

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

2014-10-01

164

Assessment of the effects of land drainage upon upland flood generation using a quasi-distributed hydrological model  

Microsoft Academic Search

The U.K. experienced widespread drainage of upland moorland during the 1940s and 1950s. This was commonly associated with shallow drains, known as grips, which were used either to convert blanket peat bog to rough pasture or heather moorland or to prepare land for afforestation. Simultaneously, flow records suggest a major increase in the magnitude and frequency of downstream flooding coincident

C. Brookes; J. Holden; M. Kirkby

2003-01-01

165

Environmental Controls over Peat Accumulation in Arctic Alaska  

NASA Astrophysics Data System (ADS)

Wide spread accumulation of peat (paludification) began on Alaska's North Slope during the Pleistocene/Holocene transition starting ca. 12,000 14C years ago and established this region as a carbon sink. Its status as a C sink is in question today because of rapid climate change. Our project's focus is on the relationship between peat, microclimate, and topography in a portion of the Arctic Foothills 300-350 km south of Point Barrow on the northern flank of the Brooks Range. Our objectives are 1) Quantify how varying microclimate factors found along a climosequence determine the thickness of the thin surface peats (<50 cm) that have developed during the Holocene; 2) Estimate peat accumulation rates on level, initially well-drained geomorphic surfaces using a 3,000 year old chronosequence on river point bars; 3) Quantify how peat accumulation affects soil temperature regimes; 4) Develop a GIS-based peat-prediction model for a 50 km2 study area and estimate this area's pool of standing carbon. We used a combination of remotely sensed data, field measurements, and a GIS to gather data regarding slope, aspect, elevation, near-ground temperature, soil moisture, temperature at the organic/mineral horizon interface, solar radiation, upslope drainage area, and lastly, peat thickness. Peat is defined here as any near-surface soil horizon containing >25% organic carbon by volume. We employ statistical analyses to examine how each factor independently influences peat thickness and what suite of factors best explains peat distribution and thickness across the landscape. Results show a significant inverse relationship (R2 = 0.27, p-value <<.001) between slope and peat thickness, with an increase in steepness accompanying a decrease in peat thickness. There is a less significant relationship (R2 = 0.03, p-value = .02) between aspect and peat thickness. There is a significant positive relationship (R2 = 0.81, P-value <<.001) between peat thickness and July active layer thickness, indicating that peat thickness and below ground temperature regimes are highly correlated. We estimated time to paludification to be 300-600 years. Initial peat accumulation rates are 0.015 - 0.031 cm/yr (R2 = 0.56, P-value <<.001). There appears to be a temporal threshold along the chronosequence at approximately 400 years. After this point the peat accumulation rate is near zero and statistically insignificant (R2 = 0.02, P-value = 0.49). This could indicate that landscapes in the Arctic Foothills approach a stable state with regards to peat development rather quickly on the geologic time scale and challenges the idea of continuous peat accumulation. Results from this project will inform a geospatial model linking peat dynamics to climate change in arctic Alaska.

Baughman, C. A.; Mann, D. H.; Heiser, P. A.; Kunz, M. L.

2012-12-01

166

CHUM: a hydrochemical model for upland catchments  

NASA Astrophysics Data System (ADS)

CHUM (CHemistry of the Uplands Model) simulates soil-water chemical interactions and water flows in upland catchments with acid soils. The chemical interactions are described with the equilibrium speciation code WHAM, which emphasises the interactions of inorganic chemical species with solid-phase and dissolved organic matter, and also considers inorganic solution speciation and sorption reactions of fulvic acid. Of special significance is the treatment of aluminium chemistry; control of dissolved aluminium concentrations is assumed to be due primarily to complexation reactions with solid phase organic matter, whereas previous models have postulated equilibrium with mineral phases or simple ion-exchange. In addition, CHUM takes nitrogen transformations and weathering (dissolution) reactions into account. The catchment is conceptualised as a series of columns consisting of two soil horizons and an underlying permeable or fractured bedrock zone. Water flows are described with a hydrological submodel that distinguishes immobile water present in soil micropores (which is in chemical equilibrium with the soil solids) from mobile drainage water. The mobile water can move vertically from one horizon to another, from one column to the column immediately downslope, or as outflow from a column adjacent to a stream or lake. Solutes exchange between the mobile and immobile compartments. The model runs on a daily time-step. The fundamentals of the model are given, together with a description of its application to a site in the English Lake District.

Tipping, Edward

1996-01-01

167

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

PubMed

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

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

2015-02-01

168

Late Holocene land-use and vegetation dynamics in an upland karst region based on pollen and coprophilous fungal spore analyses: an example from the Burren, western Ireland  

Microsoft Academic Search

The late Holocene environmental history of two karstic uplands in the Burren, western Ireland is reconstructed. The palaeoecological\\u000a investigations focus on species-rich, upland plant communities of high biogeographic interest that include Sesleria-dominated grasslands and heath communities with Dryas octopetala, Arctostaphylos uva-ursi and Empetrum nigrum. Short monoliths taken from shallow peats were pollen analytically investigated. Particular attention was paid to non-pollen

Ingo Feeser; Michael O’Connell

2010-01-01

169

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

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.

Oberbauer, S.F. [Florida International Univ., Miami, FL (United States); Gillespie, C.T. [Vandenburg Air Force Base, CA (United States); Cheng, Weixin [Desert Research Inst., Reno, NV (United States)] [and others

1996-08-01

170

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

PubMed

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 ?g 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

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

2014-08-01

171

USE OF WETLANDS BY UPLAND WILDUFE  

Microsoft Academic Search

Seasonal use of wetlands by upland wildlife is common; when uplands are dis­ turbed. wildlife may use we I lands year·round. The structure and form of vegetation in wetlands is more important than species composition 10 upland wildlife. Wetlands may provide upland wildlife with food. escape cover. protection from inclement weather. and reproductive habitat. There has been little documentation of

Frank Schiloskey. Jr

172

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

PubMed Central

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

Medina-Roldán, Eduardo; Bardgett, Richard D.

2012-01-01

173

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

NASA Astrophysics Data System (ADS)

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.

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

2009-02-01

174

The peats of Costa Rica  

SciTech Connect

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.

Thayer, G.R.

1991-01-01

175

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

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.

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

2011-01-01

176

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

NASA Astrophysics Data System (ADS)

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.

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

2015-01-01

177

Differences between valley and upland vegetation development in eastern Noord-Brabant, The Netherlands, during the Late Glacial and early Holocene  

Microsoft Academic Search

Analysis of pollen, including the determination of pollen concentrations and of relative pollen values, macrofossil analysis of peat cores from oxbows in river valleys and of pingo melt holes on the upland, and the application of recent surface samples from northern Finland have enabled the establishment of two different lines of vegetational succession, one for the valley and another for

W. van Leeuwaarden; C. R. Janssen

1987-01-01

178

46 CFR 148.290 - Peat moss.  

Code of Federal Regulations, 2012 CFR

... 2012-10-01 2012-10-01 false Peat moss. 148.290 Section 148.290 Shipping ...Requirements for Certain Materials § 148.290 Peat moss. (a) Before shipment, peat moss must be stockpiled under cover to allow...

2012-10-01

179

46 CFR 148.290 - Peat moss.  

Code of Federal Regulations, 2014 CFR

... 2014-10-01 2014-10-01 false Peat moss. 148.290 Section 148.290 Shipping ...Requirements for Certain Materials § 148.290 Peat moss. (a) Before shipment, peat moss must be stockpiled under cover to allow...

2014-10-01

180

46 CFR 148.290 - Peat moss.  

Code of Federal Regulations, 2011 CFR

... 2011-10-01 2011-10-01 false Peat moss. 148.290 Section 148.290 Shipping ...Requirements for Certain Materials § 148.290 Peat moss. (a) Before shipment, peat moss must be stockpiled under cover to allow...

2011-10-01

181

46 CFR 148.290 - Peat moss.  

Code of Federal Regulations, 2013 CFR

... 2013-10-01 2013-10-01 false Peat moss. 148.290 Section 148.290 Shipping ...Requirements for Certain Materials § 148.290 Peat moss. (a) Before shipment, peat moss must be stockpiled under cover to allow...

2013-10-01

182

Impacts of Reservoir Creation on the Biogeochemical Cycling of Methyl Mercury and Total Mercury in Boreal Upland Forests  

Microsoft Academic Search

The FLooded Upland Dynamics Experiment (FLUDEX) at the Experimental Lakes Area (ELA) in northwest Ontario was designed to test the hypothesis that methylmercury (MeHg) production in reservoirs is related to the amount, and subsequent decomposition, of flooded organic matter. Three upland forest sites that varied in the amounts of organic carbon stored in vegetation and soils (Low C, 30,870 kg

B. D. Hall; V. L. St. Louis; K. R. Rolfhus; R. A. Bodaly; K. G. Beaty; M. J. Paterson; K. A. Peech Cherewyk

2005-01-01

183

Cadmium in upland forests after vitality fertilization with wood ash—a summary of soil microbiological studies into the potential risk of cadmium release  

Microsoft Academic Search

The use of wood ash in forestry has been questioned because of the potential risk associated with its cadmium (Cd) content (1–30 mg kg ?1). In agriculture, wood ash is only allowed for use as a fertilizer when its Cd content is below 3 mg kg ?1. This restriction has not been applied to forest soils and there is a lack of

Jonna Perkiömäki; Hannu Fritze

2005-01-01

184

Biochemical processes of oligotrophic peat deposits of Vasyugan Mire  

NASA Astrophysics Data System (ADS)

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 (56Ë? 03´ and 56Ë? 57´ NL, 82Ë? 22´ and 82Ë? 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

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

2009-04-01

185

Calibration of Time Domain Reflectometry Using Undisturbed Peat Samples  

NASA Astrophysics Data System (ADS)

At present, freeze-thaw experiments on 60 cm diameter by 90 cm deep peat/permafrost cores from our central Mackenzie River basin long-term field site are being conducted to better elucidate coupled heat and moisture transport processes occurring in the active layer. Time domain reflectometry (TDR) along with 15 cm and 30 cm probes is being used to monitor the depth-specific volumetric soil moisture (VSM) in these cores. Organic soils are characterized by high porosities and soil density increases many folds at successive depths. Therefore, we calibrated the TDR for different depths and for peat with two different origins (sphagnum moss and lichen). A simple apparatus was developed to ensure a more homogenous soil moisture distribution in the undisturbed samples used for calibration. Methodology and results for the calibration as well as comparisons with mixing models at different densities are presented and the effects of different soil phases on calibration are discussed.

Nagare, R. M.; Schincariol, R. A.; Quinton, W. L.; Hayashi, M.

2009-05-01

186

Long term effects of manure, charcoal and mineral fertilization on crop production and fertility on a highly weathered Central Amazonian upland soil  

Microsoft Academic Search

Application of organic fertilizers and charcoal increase nutrient stocks in the rooting zone of crops, reduce nutrient leaching\\u000a and thus improve crop production on acid and highly weathered tropical soils. In a field trial near Manaus (Brazil) 15 different\\u000a amendment combinations based on equal amounts of carbon (C) applied through chicken manure (CM), compost, charcoal, and forest\\u000a litter were tested

Christoph Steiner; Wenceslau G. Teixeira; Johannes Lehmann; Thomas Nehls; Jeferson Luis Vasconcelos de Macêdo; Winfried E. H. Blum; Wolfgang Zech

2007-01-01

187

Explosive silicic eruptions in Iceland: from vent to peat bog  

E-print Network

Explosive silicic eruptions in Iceland: from vent to peat bog OUTLINE Microtephra horizons, found in soils across Scotland, contain fine ash produced by explosive eruptions in Iceland. They represent presented by the eruptions that produce them. ASHFALL IN SCOTLAND Ash from numerous volcanoes in Iceland can

188

The effects of drying and re-wetting and increased temperature on sulphate release from upland and wetland material  

Microsoft Academic Search

In central Ontario, elevated SO4 concentrations and export have been measured in both upland and wetland-draining catchments following summer droughts, although the source of excess SO4 is unclear. The objective of this study was to determine the effects of drying and re-wetting and temperature, respectively, on the release of SO4 from the primary S pools in wetlands (Sphagnum and peat)

M. Catherine Eimers; Peter J. Dillon; Sherry L. Schiff; Dean S. Jeffries

2003-01-01

189

Second technical contractors' conference on peat  

SciTech Connect

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)

Not Available

1980-01-01

190

The peats of Costa Rica  

SciTech Connect

The authors compare the competitive position of peat for energy with coal, oil, and cogenerative systems in gasifiers and solid-fuel boilers. They also explore the possibility for peat use in industry. To identify the major factors, they analyze costs using a Los Alamos levelized cost code, and they study parametric costs, comparing peat production in constant dollars with interest rates and return on investment. They consider costs of processing plant construction, sizes and kinds of boilers, retrofitting, peat drying, and mining methods. They examine mining requirements for Moin, Changuinola, and El Cairo and review wet mining and dewatering methods. Peat can, indeed, be competitive with other energy sources, but this depends on the ratio of fuel costs to boiler costs. This ratio is nearly constant in comparison with cogeneration in a steam-only production system. For grate boilers using Costa Rican high-ash peat, and for small nonautomatic boilers now used in Costa Rica, the authors recommend combustion tests. An appendix contains a preliminary mining plan and cost estimate for the El Cairo peat deposit. 8 refs., 43 figs., 19 tabs.

Thayer, G.R.; Williamson, K.D. Jr. (Los Alamos National Lab., NM (USA)); Ramirez, O. (RECOPE, San Jose (Costa Rica))

1991-04-01

191

An overview of peat gasification  

NASA Astrophysics Data System (ADS)

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.

Punwani, D. V.

192

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

PubMed

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 Niño 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 0.7 m 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 382 ± 82 (the mean ± 1 SD of six chambers) and 362 ± 74 gC m(-2)  yr(-1) during 2004-2005 and during 2005-2006 years, respectively. Simulated RP showed a significant negative relationship with GWL on an annual basis, which suggests that every GWL lowering by 0.1 m causes additional RP of 89 gC m(-2)  yr(-1) . The RP accounted for 21-24% of ecosystem respiration on an annual basis. PMID:23775585

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

2014-02-01

193

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

USGS Publications Warehouse

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.

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

2007-01-01

194

Water source utilization and foliar nutrient status differs between upland and flooded plant communities in wetland tree islands  

Microsoft Academic Search

Tree islands in the Everglades wetlands are centers of biodiversity and targets of restoration, yet little is known about\\u000a the pattern of water source utilization by the constituent woody plant communities: upland hammocks and flooded swamp forests.\\u000a Two potential water sources exist: (1) entrapped rainwater in the vadose zone of the organic soil (referred to as upland soil\\u000a water), that

Amartya K. SahaLeonel da Silveira; Leonel da Silveira O’Reilly Sternberg; Michael S. Ross; Fernando Miralles-Wilhelm

2010-01-01

195

What controls the oxidative ratio of UK peats? A multi-site study of elemental CHNO concentrations in peat cores  

NASA Astrophysics Data System (ADS)

The oxidative ratio (OR) is the amount of CO2 sequestered in the terrestrial biosphere for each mol of O2 produced. The OR governs the effectiveness of a terrestrial biome to mitigate the impact of anthropogenic CO2 emissions and it has been used to calculate the balance of terrestrial and oceanic carbon sinks across the globe. However, few studies have investigated the controls of the variability in OR. What factors affect OR - climate? Soil type? Vegetation type? N deposition? Land use? Land use change? Small shifts in OR could have important implications in the global partitioning of CO2 between the atmosphere, biosphere, and oceans. This study looks at peat soils from a series of sites representing a climatic transect across the UK. Duplicate peat cores were taken, along with samples of above-ground vegetation and litter, from sites in northern Scotland (Forsinard), southern Scotland (Auchencorth), northern England (Moor House; Thorne Moor) through the Welsh borders (Whixhall Moss) and Somerset levels (Westhay Moor) to Dartmoor and Bodmin Moor in the south west of England. Sub-samples of the cores were analysed for their CHNO concentrations using a Costech ECS 4010 Elemental combustion system. Using the method of Masiello et al. (2008), OR values could be calculated from these elemental concentrations. Results show that OR values of UK peats varied between 0.82 and 1.27 with a median value of 1.08 which is within the range of world soils. There were significant differences in OR of the peat between sites with the data falling into two broad groupings - Group 1: Forsinard, Auchencorth, Dartmoor and Bodmin Moor; Group 2: Moor House, Thorne Moor, Westhay Moor, Whixhall Moss. Whilst there were significant changes (p < 0.05) in elemental ratios with increasing peat depth (increasing C:N ratio and decreasing O:C ratio) there was no significant difference overall in OR with depth. This paper will explore some of the possible controlling factors on these ratios. Local vegetation was also sampled along with agricultural soils from the local area of the peat cores to compare the relative differences in different mediums. Significant differences (p < 0.01) between vegetation, agricultural soils and surface peat layers were found where vegetation had OR values of 1.03 ± 0.04 and agricultural soils had OR values of 1.15 ± 0.04. Further discussion of these results from these comparisons is also presented in this study.

Clay, Gareth; Worrall, Fred; Masiello, Carrie

2013-04-01

196

ASSESSMENT OF UPLAND EROSION PROCESSES AND FARMER'S PERCEPTION OF LAND CONSERVATION IN DEBRE-MEWI WATERSHED,  

E-print Network

ASSESSMENT OF UPLAND EROSION PROCESSES AND FARMER'S PERCEPTION OF LAND CONSERVATION IN DEBRE By Assefa Derebe Zegeye May 2009 #12;© 2009 Assefa Derebe Zegeye #12;ABSTRACT Soil erosion is affecting the last century mainly by human activity. In developing countries in order to combat erosion, many soil

Walter, M.Todd

197

The Sonoran Desert, Arizona Upland  

NSDL National Science Digital Library

This tutorial explains the ecosystem of the Arizona Upland region of the Sonoran Desert and describes the plants and animals that live there. Students will discover the interactions of the living and non-living parts of the ecosystem. There is an interactive glossary within the text.

198

Promotion of host plant growth and infection of roots with arbuscular mycorrhizal fungus Gigaspora margarita by the application of peat  

Microsoft Academic Search

The influence of the addition of peat on arbuscular mycorrhizal formation and host plant growth was investigated using a pot experiment. Peat was mixed with Masa soil at different levels (0, 25, 50, 100, 150, 200 g kg) into which an arbuscular mycorrhizal fungus (AMF) Gigaspora margarita Becker & Hall was inoculated, and seedlings of Miscanthus sinensis Anderess were planted. There was

Nan Ma; Kazuhira Yokoyama; Takuya Marumoto

2006-01-01

199

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

NASA Astrophysics Data System (ADS)

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.

Orru, M.; Orru, H.

2009-04-01

200

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

NASA Astrophysics Data System (ADS)

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.

Klavins, Maris; Purmalis, Oskars

2013-04-01

201

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

PubMed

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

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

2013-10-01

202

Evapotranspiration of tropical peat swamp forests.  

PubMed

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 Niño and La Niña 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 Niño and La Niña 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

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

2014-06-01

203

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

NASA Astrophysics Data System (ADS)

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.

Gao, Jihui; Kirkby, Mike; Holden, Joseph

2014-05-01

204

Mineralization of 13C glucose in three fine textured soils from the western boreal forest  

NASA Astrophysics Data System (ADS)

Microbial composition is known, on similar soil types, to vary based on differing organic matter inputs, or stand composition. Dominating western upland boreal forests are fine textured soils with a canopy cover of aspen (Populus tremuloides Michx.), white spruce (Picea glauca (Moench) Voss or a mixture of the two. These soils then reflect different belowground biogeochemical processing of organic matter. Anthropogenic soils, formed from a combination of peat litter and fine textured mineral soil, are now also a part of the landscape in the western boreal. This study set out to determine if a simple labelled compound (13C glucose) was processed differently between soils from the two dominant stand types (aspen and spruce) and a soil from an anthropogenic (constructed) site. Results indicate that while all three soils rapidly incorporated, and respired, the labelled carbon each maintained a distinct microbial community structure (as evidenced by phospholipid fatty acid analysis) throughout the 300 hour experiment. Therefore soils with different microbial communities from varied organic matter inputs decompose organic carbon by different processes, even in the case of simple labile compounds.

Norris, C. E.; Quideau, S. A.; Macey, D. E.

2012-04-01

205

A conceptual model of volume-change controls on the hydrology of cutover peats  

Microsoft Academic Search

Modeling hydrological processes in certain peats requires a detailed understanding of short-term changes in soil volume and it's influence on the system's hydraulic properties. A study of cutover sites abandoned for 7-years (H92) and 2-years (H97), and an undisturbed section of the Lac Saint-Jean (LSJ) cutover bog was conducted to characterize peat volume changes and its associated hydrological behaviour. Shrinkage

G. W. Kennedya

206

Estimation of global warming potential from upland cropping systems in central Hokkaido, Japan  

Microsoft Academic Search

Seven upland cropping systems in Central Hokkaido, Japan, were investigated during the growing season in 2003 to evaluate the magnitude of N2O emission, CH4 uptake and soil carbon sequestration, and their net effect on the global warming potential (GWP). N2O and CH4 fluxes were measured from field soils planted with crops and CO2 fluxes were measured from bare soils in

Zhijian Mu; Sonoko D. Kimura; Ryusuke Hatano

2006-01-01

207

The microbilogy of cut-away peat  

Microsoft Academic Search

Summary  A description is given of several surveys of fungal habitats in bare cut-away peat. These surveys are related to one another and to the general surveys of the peat microflora reported in an earlier paper of this series. The response of the peat myco-flora to cultivation of cut-away peat is reported and the colonisation of fresh organic material added to

M. Dooley; C. H. Dickinson

1970-01-01

208

CANADIAN PEAT HARVESTING AND THE ENVIRONMENT  

E-print Network

..................................................................................7 4.0 The Value of Wetlands in Our Environment................................................................6 3.0 The Canadian Peat Industry

Laval, Université

209

Peat Depth Assessment Using Airborne Geophysical Data for Carbon Stock Modelling  

NASA Astrophysics Data System (ADS)

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.

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

2013-04-01

210

Classifying and mapping wetlands and peat resources using digital cartography  

USGS Publications Warehouse

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.

Cameron, Cornelia C.; Emery, David A.

1992-01-01

211

Ecological study of peat landforms in Canada and Alaska  

NASA Technical Reports Server (NTRS)

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.

Glaser, Paul H.

1989-01-01

212

CAP and the Uplands Robert Brotherton  

E-print Network

priorities in the Uplands · high quality water suitable for drinking · reduced risk of flooding · ameliorating the impact of droughts · carbon sequestration within upland peatlands · high quality wildlife lobby #12;Why Reform CAP in 2003 WTO EU enlargement Cost (wine lakes and butter mountains) Environmental

Quinton, John

213

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...

214

Ecological assessment for the wetlands at Milltown Reservoir, Missoula, Montana: Characterization of emergent and upland habitats  

Microsoft Academic Search

Wetlands in mining districts in the western US are frequently impacted by heavy metal-contaminated sediments. The present study summarizes a soil contamination evaluation and an ecological assessment completed for a Superfund site located at Milltown Reservoir wetlands (MRW) in western Montana. For wetlands, as well as upland habitats adjacent to wetlands, biological evaluations in the field and laboratory should be

Greg Linder; Robert Hazelwood; Don Palawski; Michael Bollman; David Wilborn; John Malloy; Kristi DuBois; Suean Ott; Gary Pascoe; Julie DalSoglio

1994-01-01

215

The role of legume fallows in intensified upland rice-based systems of West Africa  

Microsoft Academic Search

Traditional upland rice-based cropping systems in West Africa rely on periods of fallow to restore soil fertility and prevent the build-up of insect pests and weeds. Demographic growth and increased demand for land is forcing many farmers to intensify their rice production systems. Declining fallow length and increasing number of crops before leaving the land to extended fallow result in

M. Becker; D. E. Johnson

1998-01-01

216

Elevated Methane Concentrations in Trees of an Upland Forest  

NASA Astrophysics Data System (ADS)

There is intense debate about whether terrestrial vegetation contributes substantially to global methane emissions. Although trees may act as a conduit for methane release from soils to atmosphere, the debate centers on whether vegetation directly produces methane by an uncharacterized, abiotic mechanism. A second mechanism of direct methane production in plants occurs when methanogens - microorganisms in the domain Archaea - colonize the wood of living trees. In the debate this biotic mechanism has largely been ignored, yet conditions that promote anaerobic activity in living wood, and hence potentially methane production, are prevalent across forests. We find average, growing season, trunk-gas methane concentrations >15,000 mL×L¬-1 in common, temperate-forest species. In upland habitat (where soils are not a significant methane source), concentrations are 2.3-times greater than in lowland areas, and wood cores produce methane in anaerobic, lab-assays. Emission rate estimates from our upland site are 52×9.5 ng CH4 m-2 s-1; rates that are of a similar magnitude to the soil methane sink in temperate forest, and equivalent in global warming potential to ~18% of the carbon likely sequestered by this forest. Additional preliminary results from a multi-authored collaborative study of the role of age-class, forest type, and latitude in driving the magnitude of emissions in the eastern forest will also be discussed. Microbial infection of one of the largest, biogenic sinks for carbon dioxide, living trees, might result in substantial, biogenic production of methane.

Covey, K. R.; Wood, S. A.; Warren, R. J.; Lee, X.; Bradford, M. A.

2013-12-01

217

Peat and its modification products as sorbents for remeval of metals, metalloids and nonmetallic elements  

NASA Astrophysics Data System (ADS)

For remediation of soils and purification of waters biosorbents 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. We have demonstrated the possibilities to use peat and its thermal treatment products for oil sorption. Peat as an oil sorbent has poor buoyancy characteristics, relatively low oil sorption capacity and low hydrophobicity. However, thermal treatment (low-temperature pyrolysis and synthesis of peat-based active coal) helps to significantly improve its sorptive characteristics. The processes and structural changes taking place during low-temperature pyrolysis have been studied by means of IR spectroscopy, thermogravimetry and scanning electron microscopy. Peat can be used also as an efficient sorbent for sorption of metallic elements as it has been demonstrated on example of Tl+, Cu2+, Cr3+, however sorption capacity in respect to nonmetallic (anionic species) elements is low. To develop such application possibilities peat, peat modified with iron compounds, iron humates were prepared and tested for sorption of arsenic 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.

Klavins, Maris; Ansone, Linda; Robalds, Artis; Dudare, Diana

2013-04-01

218

Effect of plastic-film mulching on leaching of nitrate nitrogen in an upland field converted from paddy  

Microsoft Academic Search

A lysimeter experiment was conducted to examine the effects of plastic film mulching on the leaching rate of nitrate nitrogen (NO 3-N) from chemical fertilizer that was applied to an upland field that had been converted from paddy rice production. Leaching was monitored in two lysimeters filled with sandy loam soil, which contained low soil organic matter content, under different

Tomokazu Haraguchi; Atsushi Marui; Kozue Yuge; Yoshisuke Nakano; Ken Mori

2004-01-01

219

Predicting the release of metals from ombrotrophic peat due to drought-induced acidification.  

PubMed

Ombrotrophic peats in northern England and Scotland, close to industrial areas, have substantial contents of potentially toxic metals (Al, Ni, Cu, Zn, Cd and Pb) and of pollutant sulphur, all derived from atmospheric deposition. The peat sulphur, ordinarily in reduced form, may be converted to sulphuric acid under drought conditions, due to the entry of oxygen into the peats. The consequent lowering of soil solution pH is predicted to cause the release of metals held on ligand sites of the peat organic matter. The purpose of the present study was to explore, by simulation modelling, the extent of the metal response. Chemical variables (elemental composition, pH, metal contents) were measured for samples of ombrotrophic peats from three locations. Water extracts of the peats, and samples of local surface water, were also analysed, for pH, dissolved organic carbon (DOC) and metals. Metal release from peats due to acidification was demonstrated experimentally, and could be accounted for reasonably well using a speciation code (WHAM/Model VI). These data, together with information on metal and S deposition, and meteorology, were used to construct a simple description of peat hydrochemistry, based on WHAM/Model VI, that takes into account ion-binding by humic substances (assumed to be the "active" constituents of the peat with respect to ion-binding). The model was used to simulate steady state situations that approximated the observed soil pH, metal pools and dissolved metal concentrations. Then, drought conditions were imposed, to generate increased concentrations of H2SO4, in line with those observed during the drought of 1995. The model calculations suggest that the pH will decrease from the initial steady state value of 4.3 to 3.3-3.6 during rewetting periods following droughts, depending upon assumptions about the amount of potentially mobile soil S. The pH decreases will be accompanied by increases in concentrations of dissolved metals (Mg, Al, Ca, Ni, Cu, Zn, Cd, Pb) of an order of magnitude or more, depending upon assumptions about the replenishment of soil metal pools by deposition. In the most realistic scenario for present conditions, the severity of pH depressions will gradually decline due to the relatively slow depletion of the soil S pool by droughts. However, the magnitudes of heavy metal pulses will decline quite rapidly (over two or three droughts) because current and future metal deposition is unable to compensate for leaching losses from the soil pools. PMID:12628203

Tipping, E; Smith, E J; Lawlor, A J; Hughes, S; Stevens, P A

2003-01-01

220

PwC's 3-Peat  

ERIC Educational Resources Information Center

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…

Freifeld, Lorri

2010-01-01

221

Arsenic Background Concentrations in Florida, U.S.A. Surface Soils: Determination and Interpretation  

E-print Network

arsenic distribution would underestimate potential arsenic contamination in upland soils. # 2001 AEHSArsenic Background Concentrations in Florida, U.S.A. Surface Soils: Determination 2001) Background concentrations of soil arsenic have been used as an alternative soil cleanup criterion

Ma, Lena

222

Smouldering fires and environmental reconstructions using ombrotrophic peat cores  

NASA Astrophysics Data System (ADS)

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 ?13C seems to be slightly affected by smouldering, although the information about vegetational changes are preserved, whereas the ?15N 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.

Zaccone, Claudio; Rein, Guillermo; Ciavatta, Claudio; Knicker, Heike; Shotyk, William; Miano, Teodoro M.

2014-05-01

223

Genetic differentiation revealed by selective loci of drought-responding EST-SSRs between upland and lowland rice in China.  

PubMed

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

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

2014-01-01

224

Carbon stocks and carbon fluxes from a 10 year prescribed burning chronosequence on a UK blanket peat.  

NASA Astrophysics Data System (ADS)

Prescribed burning is a common land management technique in many areas of the UK uplands. However, concern has been expressed at the impact of this management practice on carbon stocks and fluxes found in the carbon rich peat soils that underlie many of these areas. Existing data shows a range of results at differing spatial and temporal scales for a range of carbon pathways e.g. dissolved organic carbon (DOC), yet there are limited studies that monitor a suite of parameters under burning management. This study measured both carbon stocks and carbon fluxes from a chronosequence of prescribed burn sites in northern England. A range of carbon parameters were measured including: above-ground biomass and carbon stocks; net ecosystem exchange (NEE); ecosystem respiration (Reco); photosynthesis (Pg); and particulate organic carbon (POC). CO2 data was analysed using ANOVA to investigate any significant differences between burn years. Carbon budgets were also calculated using measured and modelled data. Analysis of the CO2 data showed that burning was a significant factor in measured CO2 readings but that other factors such as month of sampling explained a greater proportion of the variation in the data. Carbon budget results show that whilst all the sites were net sources of carbon, the most recent burns were smaller sources of carbon compared to the older burns (Burn year 2009: 85 ± 29 gC/m2/yr; Burn year 1999: 152 ± 12 gC/m2/yr). Additionally, the most recent burns were net sinks of gaseous CO2.

Clay, G. D.; Worrall, F.

2012-04-01

225

Altitude or slope position - gaseous carbon cycling on UK blanket peat bogs  

NASA Astrophysics Data System (ADS)

Blanket peat accounts for 87% of Britain's total peatlands and represents one of the UK's largest terrestrial carbon stores. For peatlands to accumulate carbon the net ecosystem exchange of CO2 (NEE) must be negative with respect to the atmosphere. Unlike many other peatlands, upland blanket peat bogs in the UK are draped across hillsides and so it could be that both altitude and slope position are significant controls upon the magnitude and direction of NEE. The role that altitude and slope position play on NEE in upland blanket peat is poorly constrained on a local scale. Thus a hillslope transect was set up to measure how the gaseous exchange of CO2 varies across altitude and with slope position. The slope-transect consisted of 4 sites, in the English Peak District, with three replicates per site. The transect spanned the entire margin of peat occurrence on the hillside, from the summit (447m ASL) to the lowest occurrence of peat at (378m ASL). The sites were positioned to sample each of the distinct points of the variation in slope from the flat top, to the point of slope steepening, to the point of slope leveling to the final flattening out of the slope. Each site was located in Calluna vulgaris of similar age and in the same growth phase (degenerate). Data were gathered for a year in order to sample a complete seasonal cycle. The results of analysis by ANOVA showed that altitudinal effects were either not present or so small as to be masked by other effects. However both NER and GPP seemed to be linked to slope position. ANOVA and post hoc Tukey testing showed that only the site on the point of slope steepening was significantly different to the other sites with NER being 47% higher and GPP being 63% greater than the average of the other sites. But the elevated rates of GPP and NER cancelled each other out resulting in a non-significant 3% greater rate of overall NEE from the point of slope steepening. Another slope position effect observed was that of hill foot shading. This created markedly less variable readings than on the hill top sites, with the coefficients of variation being 70%, 40% and 36% greater on the hill top sites than hill foot sites for NEE, NER and GPP respectively. This suggests shading provides a more stable environment leading to more a spatially uniform gaseous carbon cycle within a single vegetation type.

Dixon, Simon; Rowson, James; Worrall, Fred

2010-05-01

226

Nitrate and sulphate dynamics in peat subjected to different hydrological conditions: Batch experiments and field comparison  

NASA Astrophysics Data System (ADS)

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.

Bougon, N.; Auterives, C.; Aquilina, L.; Marmonier, P.; Derrider, Jo; Vandenkoornhuyse, P.

2011-12-01

227

High Precision Dating of Holocene Peat Deposits  

Microsoft Academic Search

Environmental change during the Holocene has often occurred on decadal to centennial time scales. Therefore, there is a need for high precision dating of the peat and sediment deposits which archive environmental change. This presentation is an overview of the state of the art in dating Holocene ombrotrophic peat deposits, and compares the age estimates produced by different methods in

D. Yeloff; K. Bennett; M. Blaauw; F. Chambers; B. van Geel; M. van der Linden; D. Mauquoy; J. van der Plicht; Ü. Sillasoo; P. Toms; J. Newberry; S. Brain

2006-01-01

228

Feedback control of the rate of peat formation Lisa R. Belyea1*  

E-print Network

or net sinks at present. Second, long-term rates of peat accumulation (and hence carbon sequestration and carbon sequestration. Keywords: peatlands; soil organic matter; ecosystem dynamics; carbon cycle 1). As a result of these discrepancies, estimates of the rates of carbon sequestration and emission derived from

229

Annual CO2 exchange of a peat field growing spring barley or perennial forage grass  

Microsoft Academic Search

We report on net ecosystem CO2 exchange (NEE) measurements conducted with the eddy covariance method over agricultural peat soil in the 2-year period between October 2000 and October 2002. In 2001, spring barley and undersown grass were sown on the site. After the barley harvest, the perennial forage grass was left to grow, so that in 2002 the field was

Annalea Lohila; Mika Aurela; Juha-Pekka Tuovinen; Tuomas Laurila

2004-01-01

230

Microbial Respiration and Its Consequences on Oxygen Availability in Peat Substrate  

E-print Network

91 Microbial Respiration and Its Consequences on Oxygen Availability in Peat Substrate R. Naasz, J and microorganisms respiration. For some organic soils or substrates, microbial respiration may be very high in the substrate by microorganisms. Simulation results underlined that microbial respiration could cause important

Boyer, Edmond

231

Plant Species Anaerobiosis and DOC Dynamics in a Peat-Forming Wetland, New York State  

Microsoft Academic Search

We quantified spatial and temporal patterns of dissolved organic carbon (DOC) concentrations in the shallow peat soil of a freshwater wetland (located in central New York State) and correlated the patterns with anaerobiosis in roots of the dominant plant species. Sampling was stratified in zones dominated by: lakebank sedge (Carex lacustris), common cattail (Typha latifolia), purple loosestrife (Lythrum salicaria) or

J. B. Yavitt; C. J. Williams

2004-01-01

232

Impact of managed moorland burning on DOC concentrations in soil solutions and stream waters  

NASA Astrophysics Data System (ADS)

In the UK uplands, prescribed burning of moorland vegetation is a common practice to maintain suitable habitats for game birds. Many of these landscapes are in catchments covered by significant deposits of blanket peat (typically one metre or more in depth). There is growing interest in the effect of land management on the stability of these peatland carbon stores, and their contribution to dissolved and particulate organic carbon in surface waters (DOC and POC, respectively) and subsequent effects on stream biogeochemistry and ecology. Yet there are surprisingly few published catchment-scale studies on the effect of moorland burning on DOC and POC. As part of the EMBER project, stream chemistry data were collected approximately monthly in ten upland blanket peat catchments in the UK, five of which acted as controls and were not subject to burning. The other five catchments were subject to a history of prescribed burning, typically in small patches (300-900 m2) in rotations of 8-25 years. Soil solution DOC was also monitored at four depths at two intensively studied sites (one regularly burned and one control). At the two intensive sites, soil solution DOC was considerably higher at the burned site, particularly in surface solutions where concentrations in excess of 100 mg/L were recorded on several occasions (median 37 mg/L over 18 months). The high soil solution DOC concentrations at the burned site occurred in the most recently burned plots (less than 2 years prior to start of sampling) and the lowest DOC concentrations were observed in plots burned 15-25 years previously. On average, median stream DOC and POC concentrations were approximately 43% and 35% higher respectively in burned catchments relative to control catchments. All streams exhibited peak DOC in late summer/early autumn with higher peak DOC concentrations in burned catchments (20-66 mg/L) compared to control catchments (18-54 mg/L). During winter months, DOC concentrations were low in control catchments (typically less than 15 mg/L) but were highly variable in burned catchments (9-40 mg/L), implying some instability of peat carbon stores and/or fluctuation in source. The results offer strong evidence for an impact of burning on the delivery of DOC to streams, possibly through increased surface run-off from bare or partially vegetated patches.

Palmer, Sheila; Wearing, Catherine; Johnson, Kerrylyn; Holden, Joseph; Brown, Lee

2013-04-01

233

Nutritional characteristics of the leaves of native plants growing in adverse soils of humid tropical lowlands  

Microsoft Academic Search

Acid sulfate, peat, sandy podzolic, and saline soils are widely distributed inthe lowlands of Thailand and Malaysia. The nutrient concentrations in theleaves of plants grown in these type of soils were studied with the aim ofdeveloping a nutritional strategy for adapting to such problem soils. In sagoand oil palms that were well-adapted to peat soil, the N, P, and Kconcentrations

Mitsuru Osaki; Toshihiro Watanabe; Tetsuya Ishizawa; Chairatna Nilnond; Tanit Nuyim; Takuro Shinano; Masaru Urayama; Sehat Jaya Tuah

2003-01-01

234

Interdependence of peat and vegetation in a tropical peat swamp forest.  

PubMed Central

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

Page, S E; Rieley, J O; Shotyk, W; Weiss, D

1999-01-01

235

Peat humic acids and their complex forming properties as influenced by peat humification  

NASA Astrophysics Data System (ADS)

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

Dudare, D.; Klavins, M.

2012-04-01

236

The wettability of selected organic soils in Poland  

NASA Astrophysics Data System (ADS)

The wettability was measured in the laboratory by means of two methods: Water Drop Penetration Time (WDPT) test and Thin Column Wicking (TCW) method. WDPT is fast and simple method and was used to investigate potential water repellency of analyzed samples. TCW is an indirect method and was used to determine contact angles and surface free energy components. The measurement was performed in horizontal teflon chambers for thin-layer chromatography, adapted for tubes 10 cm long. The experiment was carried out on muck soils (samples were taken from two levels of soil profile: 0-20 cm and 20-40 cm) and peat soils. There were two types of peats: low-moor peats and high moor peats. Samples of low-moor peats were taken from level 25-75 cm (alder peat) and 75-125cm (sedge peat) and 25-75 cm (peloid peat). Samples of high moor peats from level 25-175 cm (sphagnum peat) and 175-225 cm (sphagnum peat with Eriophorum). There was found no variability in persistence of potential water repellency but there were differences in values of contact angles of individual soil samples. Both muck and peat samples are extremely water repellent soils. Water droplets persisted on the surface of soils for more than 24 hours. Contact angles and surface free energy components for all samples were differentiated. Ranges of water contact angles for organic soils are from 27,54o to 96,50o. The highest values of contact angles were for sphagnum peats, and the lowest for muck soil from 20-40 cm level. It means, that there are differences in wettability between these samples. Muck soil is the best wettable and sphagnum peats is the worst wettable soil. If the content of organic compounds in the soil exceeds 40% (like in peats), the tested material displays only dispersion-type interactions. Therefore for peat soils, the technique of thin column wicking could only be used to determine the dispersive component γiLW. For muck soils it was also determined electron-acceptor (Lewis acid) γ+ and electron-donor (Lewis base) γ- surface free energy components. The authors gratefully acknowledge the Ministry of Science and Higher Education for financial support of this work (grant No. N N310 149335).

Ca?ka, A.; Hajnos, M.

2009-04-01

237

Growth of Viburnum tinus in peat-based and peat-substitute growing media  

Microsoft Academic Search

To assess the growth of ornamental shrubs in peat alternative substrates, one ornamental species, Viburnum tinus L., was cultivated in a number of different substrates in two climates: a French oceanic (Oce) and a Spanish Mediterranean (Med). In Oce, three mixtures (1\\/1, v\\/v) of Finnish peat\\/yard compost, yard compost\\/raw coir and Finnish peat\\/raw coir were used while the expanded perlite\\/composted

Vincent Guérin; Francis Lemaire; Oriol Marfà; Rafaela Caceres; Francesco Giuffrida

2001-01-01

238

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

USGS Publications Warehouse

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.

Jones, Miriam C.; Grosse, Guido; Jones, Benjamin M.; Anthony, Katey Walter

2012-01-01

239

A Few Issues on the Peat Research in the Altai Mountains  

NASA Astrophysics Data System (ADS)

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.

Inisheva, Lydia I.; Larina, Galina; Shurova, Maya

2010-05-01

240

Inorganic Horizon Development and Metal Concentrations in a Peat Deposit in Congaree National Park, SC  

NASA Astrophysics Data System (ADS)

Congaree National Park, near Columbia, South Carolina, is a closed canopy floodplain forest that contains one of the United States' largest contiguous track of old-growth bottomland forest. A portion of the park contains a groundwater fed muckswamp and is in the footprint of several ancient meanders of the Congaree River. Within one ancient meander lies an extensive peat deposit that is in itself 3.5 meters thick. Within the top 20 cm of this peat, however, an inorganic horizon has developed and varies in thickness laterally throughout the deposit. Through the use of particle size analysis, ?13C and ?15N data and heavy metal concentrations as determined by ICP-CID, we propose that this inorganic horizon has developed from association with vertical translocation of soil material from the upper portions of the peat to the layers below. This can be seen through the accumulation of clays in the lower portions of the inorganic layer and the accumulation of heavy metals in the peat just below the inorganic layer. We believe that this is occurring as an artifact of large seasonal changes in the water table in this portion of the park as plant productivity and drawdown is high in the spring and summer followed by a rise in the water table in the winter, as seen through local piezometer data. This removal of organic material from the upper peat deposits will have implications of water quality and the local carbon cycle associated with the park and the Congaree River.

Werts, S. P.; Wesselschmidt, N.

2012-12-01

241

Mass tree mortality leads to mangrove peat collapse at Bay Islands, Honduras after Hurricane Mitch  

USGS Publications Warehouse

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.

Cahoon, D.R.; Hensel, P.; Rybczyk, J.; McKee, K.L.; Proffitt, C.E.; Perez, B.C.

2003-01-01

242

Catchment-scale deposition and redistribution of Chernobyl radiocaesium in upland Britain  

SciTech Connect

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.

Higgitt, D.L.; Rowan, J.S. (Lancaster Univ. (United Kingdom)); Walling, D.E. (Univ. of Exeter (United Kingdom))

1993-01-01

243

Impacts of peatland restoration on dissolved carbon loss from eroded upland peatlands in the UK  

NASA Astrophysics Data System (ADS)

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.

Evans, M.; Stimson, A.; Allott, T. E. H. A.; Holland, N.

2012-04-01

244

HIGH SPEED ROLLER GINNING OF UPLAND COTTON  

Technology Transfer Automated Retrieval System (TEKTRAN)

An experiment was conducted to determine if upland cotton could be roller ginned at considerably higher rate than standard without compromising fiber properties, and at a rate comparable to saw ginning. A standard roller gin stand was modified to run at high speed by increasing the frequency of the ...

245

Drainage and land use impacts on changes in selected peat properties and peat degradation in West Kalimantan Province, Indonesia  

NASA Astrophysics Data System (ADS)

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.

Anshari, G. Z.; Afifudin, M.; Nuriman, M.; Gusmayanti, E.; Arianie, L.; Susana, R.; Nusantara, R. W.; Sugardjito, J.; Rafiastanto, A.

2010-11-01

246

Mobile geophysical study of peat deposits in Fuhrberger Field, Germany  

NASA Astrophysics Data System (ADS)

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.

Wunderlich, T.; Petersen, H.; Hagrey, S. A. al; Rabbel, W.

2012-04-01

247

The S-transform: a Tool for Assessing Local Changes in Biogenic Gas Content in Peat from GPR Data?  

NASA Astrophysics Data System (ADS)

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.

Terry, N.; Zhongjie, Y.; Slater, L. D.

2013-12-01

248

Greenhouse gas efflux from an impacted Malaysian tropical peat swamp (Invited)  

NASA Astrophysics Data System (ADS)

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.

Waldron, S.; Vihermaa, L. E.; Evers, S.; Garnett, M.; Newton, J.; Padfield, R.

2013-12-01

249

Effects of upland disturbance and instream restoration on hydrodynamics and ammonium uptake in headwater streams  

USGS Publications Warehouse

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.

Roberts, B.J.; Mulholland, P.J.; Houser, J.N.

2007-01-01

250

Geophysical evidence for peat basin morphology and stratigraphic controls on vegetation observed in a Northern Peatland  

NASA Astrophysics Data System (ADS)

Vegetation patterns in peatlands suggest autogenic peatland development and hydrological processes are controlling factors in peatland evolution. These processes regulate vegetation ordination by influencing pH and nutrient availability at the peat surface. Geophysical studies in Caribou Bog, a 2200-hectare peatland in central Maine, indicate a close correlation between underlying geologic deposits and dominant vegetation type. The location of pools within the bog also appears to be related to subsurface geologic materials. Electrical resistivity imaging along a 1 km transect across the central unit of Caribou Bog resolved underlying lake sediment and glacio-marine clay thickness, as well as variability in depth to glacial till. Ground penetrating radar precisely defined the organic-rich lake sediment, the glacio-marine interface, and elevated till surfaces where peat thickness is less than 10 m. Direct verification of peat and lake sediment thickness, in addition to samples of the glacio-marine and till deposits, constrained the geophysical interpretation. Wooded heath (WH) interspersed with occasional Sphagnum lawn occurs where lake sediment and glacio-marine clay accumulation is thickest. Abrupt thinning of both layers (such that peat rests directly on till in places) correlates with a sharp transition to shrub heath dominated vegetation. A major open pool area located within the WH coincides with a localized sandy mineral soil-lake sediment contact at the base of the bog. The geophysical data suggest the underlying double basin system influences peatland development and dictates vegetation patterning. Limited groundwater elevation data suggest that sub-organic sediment stratigraphy mapped with geophysics regulates water levels at the peat surface, exerting a control on vegetation patterning. The major pool area, located between the basins, appears to reflect isolation of stagnant water at a point where peat development is incomplete and thus suggests that pools exist concurrent with peatland formation.

Comas, Xavier; Slater, Lee; Reeve, Andrew

2004-08-01

251

Understanding the spatial structure of peat permeability around natural pipes in blanket peatlands  

NASA Astrophysics Data System (ADS)

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.

Cunliffe, Andrew; Baird, Andy; Holden, Joseph

2014-05-01

252

How old is upland catchment water?  

NASA Astrophysics Data System (ADS)

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.

Hofmann, Harald; Cartwright, Ian; Morgenstern, Uwe; Gilfedder, Benjamin

2014-05-01

253

Fixed-bed gasification research using US coals. Volume 11. Gasification of Minnesota peat. [Peat pellets and peat sods  

SciTech Connect

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.

Thimsen, D.; Maurer, R.E.; Pooler, A.R.; Pui, D.; Liu, B.; Kittelson, D.

1985-05-01

254

Immunomodulative properties of humic peat preparations  

NASA Astrophysics Data System (ADS)

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.

Stepchenko, L. M.; Syedykh, N. J.

2010-05-01

255

Hydrological Simulation of Runoff from Peat Harvesting Areas Using DRAINMOD  

NASA Astrophysics Data System (ADS)

Peatland drainage and harvesting cause considerable impacts on runoff water quantity and quality. A crucial water quality problem is leaching of nutrients and sediment that occur after summer rainfall and leaching of acid water after groundwater level drawdown on peatlands overlaying acid sulphate soils. Groundwater fluctuations and drain runoff are important parameters that should be better predicted and monitored for load prediction. Also performance and efficiency of drainage network and different water treatment methods depend on good prediction of these parameters during design phase. In order to prevent and control pollution from drained peatlands, The DRAINMOD model has been developed for soils with shallow water table (Skaggs, 1980). The model simulates hourly hydrological response to rainfall using soil characteristics, drainage specifications and climatological data as input. The main objective of this research is to test the model for hydrological simulation of groundwater level fluctuations and estimation the amount of drained water in two peat harvesting areas in north of Finland. In order to collecting data different loggers are installed in each area to observe groundwater level, drainage water and rain continuously since summer of 2012. Several soil profiles were taken from mentioned sites and tested in the laboratory and some measuring were done in the field to determine soil characteristics as well. Water table depth (WTD) data that were collected during observation period are used for model calibration and validation. Some outliers occurred for certain events, but most simulated values of WTD are matched with observed data, both in terms of timing and quantity, thus, it can be concluded that the model performed satisfactorily for peat harvesting sites. The model allow to simulate daily amount of infiltration, evapotranspiration, runoff, drainage water and water table depth that are useful in the design of control structures, storage and sediment ponds, pump stations and treatment facilities. References Skaggs, R. W. 1980. DRAINMOD reference report. Fort Worth, Tex.: USDA-SCS South National Technical Center. Available at: www.bae.ncsu.edu/soil_water/documents/drainmod/chapter1.pdf

Mohammadighavam, Shahram; Kløve, Bjørn

2014-05-01

256

Effects of Nutrient Enrichment on Microbial Communities and Carbon Cycling in Wetland Soils  

NASA Astrophysics Data System (ADS)

Soil microbial communities are responsible for catalyzing biogeochemical transformations underlying critical wetland functions, including cycling of carbon (C) and nutrients, and emissions of greenhouse gasses (GHG). Alteration of nutrient availability in wetland soils may commonly occur as the result of anthropogenic impacts including runoff from human land uses in uplands, alteration of hydrology, and atmospheric deposition. However, the impacts of altered nutrient availability on microbial communities and carbon cycling in wetland soils are poorly understood. To assess these impacts, soil microbial communities and carbon cycling were determined in replicate experimental nutrient addition plots (control, +N, +P, +NP) across several wetland types, including pocosin peat bogs (NC), freshwater tidal marshes (GA), and tidal salt marshes (SC). Microbial communities were determined by pyrosequencing (Roche 454) extracted soil DNA, targeting both bacteria (16S rDNA) and fungi (LSU) at a depth of ca. 1000 sequences per plot. Wetland carbon cycling was evaluated using static chambers to determine soil GHG fluxes, and plant inclusion chambers were used to determine ecosystem C cycling. Soil bacterial communities responded to nutrient addition treatments in freshwater and tidal marshes, while fungal communities did not respond to treatments in any of our sites. We also compared microbial communities to continuous biogeochemical variables in soil, and found that bacterial community composition was correlated only with the content and availability of soil phosphorus, while fungi responded to phosphorus stoichiometry and soil pH. Surprisingly, we did not find a significant effect of our nutrient addition treatments on most metrics of carbon cycling. However, we did find that several metrics of soil carbon cycling appeared much more related to soil phosphorus than to nitrogen or soil carbon pools. Finally, while overall microbial community composition was weakly correlated with soil carbon cycling, our work did identify a small number of individual taxonomic groups that were more strongly correlated with soil CO2 flux. These results suggest that a small number of microbial groups may potentially serve as keystone taxa (and functional indicators), which simple community fingerprinting approaches may overlook. Our results also demonstrate strong effects of soil phosphorus availability on both microbial communities and soil carbon cycling, even in wetland types traditionally considered to be nitrogen limited.

Hartman, W.; Neubauer, S. C.; Richardson, C. J.

2013-12-01

257

The Role of Alternative Respiration Pathways and the Effect of Nutrient Loading on Peat Decomposition in Plum  

E-print Network

1 The Role of Alternative Respiration Pathways and the Effect of Nutrient Loading on Peat, weakening soil structure and contributing to marsh subsidence. In this study, rates of aerobic respiration of respiration in sediment slurries over a fourteen day period, however, results showed evidence of increased

Vallino, Joseph J.

258

Relationships between labile organic matter and nitrogen mineralization in Japanese agricultural soils with reference to land use and soil type  

Microsoft Academic Search

The relationship between the amount of organic matter determined using various extraction methods and the nitrogen mineralization potential (N0) in soil was examined with reference to land use (upland and paddy soils) and soil type (non-volcanic and volcanic soils). Surface soils were collected from agricultural lands all over Japan (n = 72). Seven methods of extracting labile organic matter were used: water

Shuji Sano; Junta Yanai; Takashi Kosaki

2006-01-01

259

Thermal energy storage composition comprising peat moss  

SciTech Connect

Peat moss is used in a thermal energy storage composition to provide a network in which to trap an incongruently melting salt hydrate capable of storing thermal energy as latent heat of phase change. The peat moss network is effective in preventing the segregation of a dehydrated form of the salt between heating and cooling cycles. In a preferred embodiment that salt hydrate is the decahydrate of sodium sulphate. A nucleating agent such as sodium tetraborate decahydrate is included to prevent supercooling in the composition, and promote crystallization of the decahydrate of sodium sulphate.

Rueffel, P.G.

1980-11-04

260

Sulfur diagenesis in everglades peat and origin of pyrite in coal  

USGS Publications Warehouse

The pattern of sulfur transformation in peat across the Everglades basin indicates that pyrite formation in organic-rich swamps depends on the use of organic oxysulfur compounds in dissimilatory respiration by sulfur-reducing bacteria. This paragenesis explains the primary distribution of sulfur compounds in low-sulfur coals and possibly in most coals and many organic-rich soils and sediments. It also accounts for the occurrence of framboidal pyrite bound in fossil tissue in coal and sediments.

Altschuler, Z.S.; Schnepfe, M.M.; Silber, C.C.; Simon, F.O.

1983-01-01

261

Sulfur diagenesis in Everglades peat and origin of pyrite in coal  

Microsoft Academic Search

The pattern of sulfur transformation in peat across the Everglades basin indicates that pyrite formation in organic-rich swamps depends on the use of organic oxysulfur compounds in dissimilatory respiration by sulfur-reducing bacteria. This paragenesis explains the primary distribution of sulfur compounds in low-sulfur coals and possibly in most coals and many organic-rich soils and sediments. It also accounts for the

Z. S. Altschuler; M. M. Schnepfe; C. C. Silber; F. O. Simon

1983-01-01

262

Evaluation of Greek low-rank coals as potential raw material for the production of soil amendments and organic fertilizers  

Microsoft Academic Search

This study evaluates Greek peat and coal samples for applications in the agricultural\\/horticultural sector and assesses the suitability of a certain peat\\/coal either as soil conditioner or as raw material for manufacturing organic fertilizers.Twenty-six samples of different rank ranging from peat to subbituminous coal obtained from several Greek peat\\/coal deposits, were studied. The laboratory tests included: a) pH and electrical

Andriana Giannouli; Stavros Kalaitzidis; George Siavalas; Adamantia Chatziapostolou; Kimon Christanis; Stefanos Papazisimou; Cassiani Papanicolaou; Antonis Foscolos

2009-01-01

263

Toxic gas emissions from the Kayseri peat deposit, central Anatolia, Turkey  

NASA Astrophysics Data System (ADS)

Toxic gases evolving from the soil in urbanized peatland regions constitute a serious hazard since buildings may be subject to the direct ingress of volatiles into the structures. Peat formed in swamp and rarely exposed to subaerial conditions has been associated with the development of the folded foreland of the Quaternary Kayseri pull-apart basin. The peat deposit is extensively urbanized but so far no studies have evaluated the extent of the ground gas hazard. In this paper, the geology, petrography and chemical variation of the Kayseri peat deposit have been studied in order to predict the public health risk from the land gases' behaviour, especially in soil gases. The main volatile species detected are methane (CH4), hydrogen sulphide (H2S) and carbon dioxide (CO2), all of which are highly toxic. The primary means of gas entry is directly from the ground through the floors, walls, and especially subsurface telephone cable pipes. Indoor vents emit 1000-70,000 ppm CH4, 330-49,000 ppm CO2 and 3.8-6.5 ppm H2S in soil and subsurface pipes; concentrations high enough to present an acute respiratory hazard to persons close to the vents.

?ener, Mehmet; Korkanç, Mustafa; Furkan ?ener, M.; Ya?ar Korkanç, Selma; Zafer Özgür, F.

2012-10-01

264

Responsible management of peatlands in Canada, from peat industry to oil sands  

NASA Astrophysics Data System (ADS)

Canada harbors one third of the peat resources of the world. Peat is an accumulated organic matter composed of dead and partly decomposed plant material, forming huge deposit through time in wetlands like peatlands and boreal coniferous swamps. Peat is a valuable resource as a growing media and soil amendments, an eco-friendly absorbent, also used as biofilters, for body care and for wastewater treatment. Peatlands also offer valuable ecological services : for example, they are the most efficient terrestrial ecosystem to store carbon on a long-term basis. Their ability to "cool off" the planet warrants a good look at their management. The horticultural peat industry of Canada has invested 22 years in R&D in habitat restoration and is now a strong leader in managing industrial peatlands in a sustainable way. The oil sand industry, which is strongly impacting the wetland landscapes of northern Canada, does realize that it has to reduce its ecological footprint, which is heavily criticized around the world. Decommissioned open mines near Fort McMurray have already begun recreating peatland ecosystems, and some restoration attempts of former oil pads are underway in the Peace River region. But the restoration of the largely disturbed wetland landscape of the oil sands is commanding innovative solutions.

Rochefort, Line

2013-04-01

265

Mangrove peat analysis and reconstruction of vegetation history at the Pelican Cays, Belize  

USGS Publications Warehouse

The substrate beneath mangrove forests in the Pelican Cays complex is predominately peat composed mainly of mangrove roots. Leaves and wood account for less than 20% of the peat mass. At Cat Cay, the depth of the peat ranges from 0.2 m along the shoreline to 1.65 m in the island center, indicating that the island has expanded horizontally as well as vertically through below-ground, biogenic processes. Mangrove roots thus play a critical role in the soil formation, vertical accretion, and stability of these mangrove cays. The species composition of fossil roots changes markedly with depth: Rhizophora mangle (red mangrove) was the initial colonizer on a coral base, followed by Avicennia germinans (black mangrove), which increased in abundance and expanded radially from the center of the island. The center of the Avicennia stand ultimately died, leaving an unvegetated, shallow pond. The peat thus retains a record of mangrove development, succession, and deterioration in response to sea-level change and concomitant hydroedaphic conditions controlling dispersal, establishment, growth, and mortality of mangroves on oceanic islands in Belize.

McKee, K.L.; Faulkner, P.L.

2000-01-01

266

Analysis of ecological factors limiting the destruction of high-moor peat  

NASA Astrophysics Data System (ADS)

This review presents an analysis of literature data and original studies by the authors aimed at revealing the factors inhibiting the destruction of high-moor (oligotrophic) peat. Each of the ecological factors that prevent the decomposition of the high-moor peat by different groups of microorganisms is considered. The acid reaction, low temperatures, and lack of nutrients were found not to be the primary factors inhibiting the destruction of the peat. The limited content of oxygen in the peatbogs leads to a drastic decrease in the number of mycelial microorganisms and a reduction of the activity of hydrolytic and oxidizing enzymes. The main factor inhibiting the decomposition of sphagnum is its mechanical and chemical stability, since animals crushing sphagnum are absent in the soil, and this moss has polysaccharides of special composition. The toxicity of phenol compounds, which is manifested under the aerobic conditions, prevents the activity of all the hydrolytic enzymes. This is the main reason for the slow decomposition of sphagnum peat and the long-term preservation of the residues of bodies and food in high-moor peatlands.

Dobrovol'skaya, T. G.; Golovchenko, A. V.; Zvyagintsev, D. G.

2014-03-01

267

Estimating sphagnum peat hydraulic properties from laboratory evaporation experiments  

NASA Astrophysics Data System (ADS)

In ombrotrophic peatlands, the equilibrium between the production and decay of organic matter is principally controlled by the moisture state and its oxic/anoxic conditions in the vadose zone. In order to predict a peatland's fate, it is necessary to describe the hydraulic processes with models correctly. However, no suitable systematic and mechanistic model exists to date. This knowledge gap is attributed to the complexity of peatland ecosystem processes. The reasons for this probably include spatial and temporal heterogeneities, swelling and shrinkage phenomena, hydrophobicity and difficulties in representative sampling. For a valid description of the non-linear processes involved, peat soil hydraulic properties play an intricate part. Their determination requires taking the characteristics mentioned into considered. Our research aims to quantify these characteristics and, eventually, to establish a model in order to numerically simulate the water fluxes in the unsaturated zone. We started with laboratory measurements with which we determined peat soil hydraulic properties. Our study is based on an ombrotrophic peatland site in the Harz Mountains (Germany). Samples were taken over the entire unsaturated part of a Histosol profile. Before the laboratory experiments, samples were frozen, cut to shape and subsequently fully saturated in a vacuum. We used the same sample specimen for the saturated hydraulic conductivity and the simplified evaporation method. Results show that the hydraulic properties rapidly change in the upper-most layers with a step-like change over a small distance, close to the permanently saturated zone. We also show that the swelling and shrinkage is considerable, which means that traditional concepts based on the rigidity of the porous media are not applicable. Furthermore, the results indicate that the frequently used van Genuchten model cannot describe our data very well.

Weber, Tobias K. D.; Durner, Wolfgang

2013-04-01

268

GAM & RF for 3D mapping of multinomial peat properties.  

NASA Astrophysics Data System (ADS)

Different statistical methods have been proposed for fitting the empirical quantitative function linking the soil information to the scorpan factors, while taking into account the spatial structure of the data . Regression kriging extends the methods of kriging and co-kriging and it has been further extended by the use of GAMs (Generalized Additive Models) with the estimation of uncertainty. When multinomial data are modelled, advanced non-parametric methods, such as CART (Classification and Regression Tree), can be used. CARTs have been used widely to estimate soil properties. Bagging trees and Random Forest (RF) approaches have among the best performances among CART methods. CARTs have been used in DSM applications, While RF have often been used in ecological modelling, fewer examples exist in DSM, such as soil erosion occurrence, soil types prediction and soil organic carbon content. In this paper we propose a methodology to map multinomial peat properties in 3D space with a combination of GAMs and RF. The methodology was applied to the humification (according to the VonPost classification) classes in a bog (18 km2) in the north-east of Scotland. A large survey campaign was carried out in 1955 and humification information were collected at 125 points. In order to integrate the information from the GAM in the RT, a series of binary GAMs were fitted using DEM-derived information as covariates. The binary GAMs were fitted assigning 1 if the class considered was present at the location, 0 if the class considered was absent. The probability predictions resulting from the binary GAMs, were included in the pool of covariates used for the RT together with other ancillary covariates. The model diagnostics had a fair to good agreement between measured and modelled values (K statistics). The probability predictions resulting from the binary GAMs proved to be important variables, increasing the agreement of the model. The obtained spatial distribution of values on the surface of the bog presented higher humification degree in the northern part and where the peat is shallower. The lowest values are in the steeper regions and on the borders of the bog, while intermediate classes can be found in the area of the raised basin. The study was implemented using open source software, in particular GRASS and R.

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

2013-04-01

269

A S-isotope approach to determine the relative contribution of redox processes to net SO 4 export from upland, and wetland-dominated catchments  

NASA Astrophysics Data System (ADS)

Reoxidation of S stored in lowlands after summer droughts has been reported to be responsible for the excess SO 4 export observed in many catchments in south central Ontario. Stable S isotopes can be used to identify the source of SO 4 export in stream water, and are particularly well suited to evaluating zones of dissimilatory SO 4 reduction (DSR) and the contribution of oxidation of reduced S species to stream SO 4. The Plastic Lake-1 (PC1) stream drains an upland coniferous forest and then passes through a Sphagnum-dominated swamp before discharging to Plastic Lake. Measurements of SO 4 fluxes and isotope ratios were used to determine the source of net SO 4 export and the contribution of redox processes to S retention and export in the upland and wetland, respectively. Mass balance budgets for the years 1999/00 and 2000/01, which had comparatively wet summers, indicated that the upland part of the catchment consistently exported SO 4 in excess of bulk deposition inputs. In contrast, mass budget calculations for the swamp indicated a net retention of 3 and 2 g S-SO 4/m 2 of wetland area, in 1999/00 and 2000/01 respectively. Higher ? 34SO 4 ratios and lower SO 4 concentrations in the swamp outflow (average +8.6 ± 2.6‰; 1.5 ± 0.6 mg S-SO 4/L) compared to the inflow draining the upland (+5.4 ± 0.7‰; 2.4 ± 0.3 mg S-SO 4/L) indicated that DSR was at least partly responsible for net SO 4 retention in the swamp. Isotope values in upland stream water (+5.7 ± 0.7‰) were only slightly higher than values in bulk deposition (average +5.1 ± 0.6‰) and soil leachate (+4.4 ± 0.4‰) over the 2-year period of study. Similar ? 34SO 4 values in upland stream water compared to deposition and soil leachate, despite substantial variations in water table height in the streambed (92 cm), suggest that reoxidation of reduced sulphides is not an important contributor to SO 4 export from the upland. Rather, net SO 4 export from the upland subcatchment is likely due to net release from upland soil, and slight differences in ? 34SO 4 between bulk deposition and soil leachate are consistent with SO 4 release from organic S forms.

Eimers, M. C.; Dillon, P. J.; Schiff, S. L.

2004-09-01

270

INFLUENCE OF PEAT ON FENTON OXIDATION  

EPA Science Inventory

A diagnostic probe was used to estimate the activity of Fenton-derived hydroxyl radicals (@OH), reaction kinetics, and oxidation efficiency in batch suspensions comprised of silica sand, crushed goethite ("-FeOOH) ore, peat, and H2O2 (0.13 mM). A simple method of kinetic analysi...

271

SOME CONSIDERATIONS OF TROPICAL PEAT FOR ENERGY  

Microsoft Academic Search

SUMMARY Indonesia as one of the oil exporting countries, at the present time has to find other energy sources to substitute for petroleum oil, because the fossil fuel reserve in Indonesia is becoming less and less. The success of peat utilization for energy especially by some temperate zone countries such as Finland and some member states of the former USSR,

Basuki Sumawinata; Budi Mulyanto; Gunawan Djajakirana; Heru B. Pulunggono

272

Equivalent weight of humic acid from peat  

USGS Publications Warehouse

By means of discontinuous titration, the equivalent weight of humic acid isolated from a peat was found to increase from 144 to 183 between the third and fifty-second day after the humic acid was dissolved. Infra-red studies showed that the material had probably condensed with loss of carbonyl groups. ?? 1960.

Pommer, A.M.; Breger, I.A.

1960-01-01

273

Equivalent weight of humic acid from peat  

Microsoft Academic Search

By means of discontinuous titration, the equivalent weight of humic acid isolated from a peat was found to increase from 144 to 183 between the third and fifty-second day after the humic acid was dissolved. Infra-red studies showed that the material had probably condensed with loss of carbonyl groups.

A. M. Pommer; I. A. Breger

1960-01-01

274

Experiments and Observation of Peat Smouldering Fires   

E-print Network

of ~20 cm) made of insulating side-walls and open on the top. The sample is ignited using an electrically heated coil running along one side of the peat. A successful ignition is followed by sustained smouldering combustion that consumes the sample...

Ashton, Clare; Rein, Guillermo; Dios, JD; Torero, Jose L; Legg, C; Davies, M; Gray, A

2007-01-30

275

Some geochemical features of peat lands of the western peat-marsh range  

NASA Astrophysics Data System (ADS)

The terrain of the western peat-marsh range within Russia coincides with administrative borders of Bryansk range, and as a whole differs uniformity of natural settings. It has affected relative uniformity of type of the peat deposits propagated here, as a rule, low moor phylum, is frequent with the raised ash content and a degree of decomposition. For an assessment of concentration of trace substances in peat comparison of their content with clarke is used. In peat of studied area bunches of trace substances vigorous (transitive - Co, Mo, Zn, Pb, Cs, Cd are secured; lowmoor - Co, Mo, Ni, Cu, Cd, Cs), an average (transitive - Ni, Cu; lowmoor - Zn, Sr, Pb) and weak (transitive - Cr, Mn, Sr, Li; low moor - Cr, Mn, Li) accumulations. High motility of trace substances (Co, Mo, Zn, Cu, Mn) in peat is shown. The greatest motility manganese - to 90 %, the least cobalt - 20-30 % possesses. Correlation coefficients and the regression equations, between the total content and exchange forms of trace substances are calculated. The received results will be co-ordinated with literary data. The increased content of trace substances in peat high layers is noted. It is bound as about dust receipt on a moor surface, and to bioaccumulation of trace substances by plants.

Chekin, G. V.; Kreshtapova, V. N.

2010-05-01

276

Modulation of headcut soil erosion in rills due to upstream sediment loads  

Technology Transfer Automated Retrieval System (TEKTRAN)

Headcut erosion can severely accelerate soil loss in upland concentrated flows and lead to significant soil degradation in agricultural areas. Previous experimental work has demonstrated that actively migrating headcuts display systematic morphodynamic behavior, and impinging jet theory can provide...

277

Adsorption and transport of pyrithiobac in soils  

E-print Network

adsorbents (Gonzales bentonite, Georgia kaolinite, goethite, and Michigan peat) and four soils (Houston Black c, Hidalgo sl, Orelia scl, and Ships sic) having a wide range of physical and chemical properties. Adsorption isotherms were developed...

Matocha, Christopher John

1996-01-01

278

Seasonality in water, carbon, and nitrogen fluxes from an upland boreal catchment underlain by continuous permafrost  

NASA Astrophysics Data System (ADS)

The balance between runoff and catchment residence time is critical to the biogeochemical processing of carbon (C) and nitrogen (N) in boreal ecosystems. Whether C is mineralized in soils or flushed from catchments depends on hydrologic fluxes and has implications for ecosystem productivity and climate change feedbacks. By measuring water fluxes and organic matter concentrations, we hope to elucidate the hydrologic and biogeochemical processes controlling C fate and transport in an upland boreal catchment underlain by permafrost. To understand the seasonal dynamics of water, C, and N fluxes, we monitored soil moisture, water chemistry, stream and subsurface flow, and conducted five conservative tracer additions in an upland catchment in the Yukon River Basin, Alaska. Tracer was added to a 2nd - order stream draining the north-facing hillslope during varying flow regimes in the summers of 2008 and 2009. Synoptic sampling and transient storage modeling results were used to explore the dynamics between hydrologic flux, and organic matter biogeochemistry in the soils and streams of this watershed. Silty hillslope soils were typically unsaturated, indicating that flow occurs predominantly through shallow, organic soils. Seasonal increases in runoff coefficients and major ion concentrations indicate greater contact with mineral soils later in the season, providing evidence that there is some flow through thawing preferential flowpaths (ie. soil pipes and/or thermokarst features) in the silt. Stream dissolved organic carbon (DOC) and nitrate concentrations were proportional to discharge at all but the lowest flows, indicating that precipitation leaches material from organic soils and transports it from the catchment. Stream DOC and nitrate concentrations were lower than expected given in-stream transport and inflows, suggesting that biogeochemical reactions were occurring. These reactions were modeled as first order decay of DOC and nitrate concentrations, and decreased seasonally, despite the fact that DOC became more labile. We believe that this indicates decreased reaction potential in the deeper subsurface flowpaths that develop later in the season, precluding water/organic soil contact. Our results highlight the importance of small surface streams and preferential flowpaths to water, C, and N export in the frozen silt uplands of interior Alaska, and identify a seasonal trend that controls stream C and N loads. Such hydrologic data is critical to our understanding of C fate and transport and provides important insight relevant to predicting boreal ecosystem changes that will likely occur as the arctic becomes warmer and wetter.

Koch, J. C.; Striegl, R. G.; Runkel, R. L.; Ewing, S. A.; McKnight, D. M.

2010-12-01

279

The variability in fallout content of soils and plants and the design of optimum field samplings strategies  

SciTech Connect

Sampling was carried out at an upland peat site in Ireland to assess the variability in {sup 137}Cs deposition to soils and activity concentration in individual vegetation species. A 3,600 m{sup 2} quadrat was laid out, and a soil core was extracted within each of sixteen 20 x 20 cm soil monoliths. The coefficient of variation values for {sup 137}Cs deposition and activity in individual soil horizons were in all cases greater than 30%, and the relative variability between corresponding horizons tended to increase with depth. Samples of Calluna vulgaris and Juncus squarrosus were taken at each soil sampling location and coefficients of variation for {sup 137}Cs activity in these species were 12 and 20%, respectively. The data was used to examine the relationship between the number of samples analyzed in a survey, the variability within those samples, and the way those two factors affect our ability to detect between-site differences in {sup 137}Cs contamination levels. A methodology is developed for detection of between-site differences in {sup 137}Cs contamination under different experimental criteria. The data show that, of the sample types examined, between-site differences could he detected most efficiently with C vulgarism Because of the variability associated with the {sup 137}Cs content of each sample type, between-site differences could be detected with fewer plant samples than soil samples. Plant-soil concentration ratios, transfer factors, and plant-plant ratios were calculated from the data, and the variability associated with each parameter was assessed. The variation among values for plant-plant ratios was less than among concentration ratios, and the greatest spread of values was associated with plant-soil transfer factors. 32 refs., 3 figs., 3 tabs.

McGee, E.J.; Synnott, H.J.; Colgan, P.A. [Radiological Institute of Ireland, Dublin (Ireland)] [and others

1995-03-01

280

Beneath the Arctic Green: Have recent increases in plant production been offset by increases in soil decomposition?  

NASA Astrophysics Data System (ADS)

Observational and modeling studies suggest that boreal vegetation has undergone an increase in plant production and C uptake in recent decades, coincident with increases in regional air temperatures, atmospheric CO2 concentration, and fire/successional dynamics. In the North American boreal forest, wildfires have increased in extent, season length, and depth of burn, driving higher C emission from black spruce ecosystems. Meanwhile, responses in soil systems that dictate the net ecosystem carbon (C) balance are less well known, in part owing to problems with elucidating the relatively small signals of organic matter decomposition from the large C fluxes of gross primary production and ecosystem respiration. Here, we measured net C accumulation in soils from Interior Alaska using radiocarbon (14C), lead isotopes (210Pb), cesium isotopes (137Cs), and time sequences of forest regeneration (fire and thaw chronosequences). We use soil 14C and non-steady-state models to estimate turnover times for soil organic C. Over the past century, rates of soil C uptake based on upland chronosequences ranged from -20 to -30 g C/m2/yr, but regionally likely shifted toward a reduced sink or source of - 20 to + 10 g C/m2/yr in recent decades due to increased combustion losses and deep C mobilization associated with permafrost thaw. C accumulation rates in lowland thermokarst chronosequences suggest a mixed sink/source effect, with post-thaw increases in surface accumulation potentially offset by decomposition at depth, or enhanced initial decomposition of C from previously frozen soils, followed by long-term net uptake of post-thaw peat. Large uncertainties remain regarding the turnover of soil organic C in boreal soil, yet enhanced decomposition has likely offset the increase in NPP, resulting in a reduced sink activity relative to pre1960s.

Harden, J. W.; O'Donnell, J.; Fuller, C.; Sierra, C. A.; Johnson, K. D.; Manies, K.; Jorgenson, T.; Jones, M.; Ewing, S. A.; Yue, C.; Turetsky, M.

2013-12-01

281

VEGETATION ANALYSIS OF UPLAND BURREN GRASSLANDS OF CONSERVATION INTEREST  

Microsoft Academic Search

This study addresses the classification of grassland and heath communities found within the Burren uplands of Co. Clare and identifies threats to their integrity. Quadrats were taken on a range of sites, focusing on semi-natural, upland grassland and heath of conservation interest. Before analysis, the data set was divided into a heath group and a grassland group based on cover

Sharon Parr; Grace O'Donovan; Stephen Ward; John A. Finn

2009-01-01

282

Dynamic Conservation Management of Nontillable East Mediterranean Upland  

E-print Network

Dynamic Conservation Management of Nontillable East Mediterranean Upland Ecosystems1 Z. Naveh2 1 Prepared for the Symposium on Dynamics and Management of Mediterranean-type Ecosystems, June 22-26, 1981, Haifa, Israel 32 000. Abstract: East Mediterranean upland ecosystems are severely threatened

Standiford, Richard B.

283

SPILOGALE GRACILIS IN UPLAND FORESTS OF WESTERN WASHINGTON AND OREGON  

Microsoft Academic Search

During surveys of upland forests in the Tsuga heterophylla Zone in Washington and Oregon, 1986 to 1996, we caught 192 S. gracilis. In the Oregon Coast Range, more (85%) S. gracilis were caught in oldeilar to Coast Range old growth (P = 0.60) with no differences between seral stages (P = 0.74). No S. gracilis were caught in upland forests

ANDREW B. CAREY; JANET E. KERSHNER

1996-01-01

284

Evidence for the silicate source of relict soils on the Edwards Plateau, central Texas  

Microsoft Academic Search

Relict soils provide insights into Quaternary soil formation and erosion on the Edwards Plateau of central Texas and into soil-forming processes in karst terranes. Late Quaternary climate-driven soil erosion produced a mosaic of thick and thin soils on the Edwards Plateau landscape. Thick soils on uplands of the Edwards Plateau are interpreted to be relicts of a formerly more extensive

M. Jennifer Cooke; Libby A. Stern; Jay L. Banner; Lawrence E. Mack

2007-01-01

285

Northern Hemisphere control of deglacial vegetation changes in the Rufiji uplands (Tanzania)  

NASA Astrophysics Data System (ADS)

In tropical Eastern Africa, vegetation distribution is largely controlled by regional hydrology which has varied over the past 20 000 years. Therefore, accurate reconstructions of past vegetation and hydrological changes are crucial to better understand climate variability in the tropical Eastern African region. Through high-resolution pollen records from a marine sediment core recovered offshore the Rufiji River, our data show significant shifts in pollen assemblages during the last deglaciation identifying, through respective changes in both upland and lowland vegetation, specific responses of plant communities to atmospheric (precipitation) and coastal (coastal dynamics/sea level changes) alterations. Specifically, an interval of maximum pollen representation of dry and open vegetation occurred during the Northern Hemisphere cold Heinrich event 1 (H1) suggesting the expansion of drier upland vegetation under arid conditions. This dry spell is followed by an interval in which forest and humid woodland expanded, indicating a hydrologic shift towards more humid conditions. Droughts during H1 and the return to humid conditions around ~14.8 kyr BP in the uplands are primarily attributed to latitudinal shifts of the Intertropical Convergence Zone (ITCZ) driven by high-latitude Northern Hemisphere climatic fluctuations. Additionally, our results show that the lowland vegetation, consisting of a well developed salt marshes and mangroves in a successional pattern typical for vegetation occurring in intertidal habitats, has responded mainly to local coastal dynamics related to marine inundation frequencies and soil salinity in the Rufiji Delta as well as the local moisture availability. Lowland vegetation shows a substantial expansion of mangrove trees after ~14.8 kyr BP suggesting also an increased moisture availability and river runoff in the coastal area. The results of this study highlight the de-coupled climatic and environmental processes to which the vegetation in the uplands and the Rufiji Delta has responded during the last deglaciation.

Bouimetarhan, I.; Dupont, L.; Kuhlmann, H.; Pätzold, J.; Prange, M.; Schefuß, E.; Zonneveld, K.

2014-09-01

286

Soils  

NSDL National Science Digital Library

The purpose of the handout is to identify the three major types of soils: pedalfer, pedocal, and laterite, and to understand the soil profile. This is accomplished with brief descriptions of the soil horizons and the designation of common elements to pedalfers, pedocals, and laterite soils. The handout is concluded with a discussion of soil erosion. Links are provided to the online Physical Geology resources at Georgia Perimeter College.

Gore, Pamela

1995-08-29

287

The efficiency of a peat biofilter treatment system and the impacts on groundwater quality  

SciTech Connect

This paper describes the performance of the peat biofilter system in Virginia from July of 1997 to January of 1998. The performance of the systems has been monitored by the Civil and Environmental Engineering Department of Old Dominion University in accordance with the guidelines recommended by the Virginia Department of Health. The monitoring results from 123 systems installed in four different soil types operating under various climatic conditions are discussed. The effects of the systems on the groundwater in the various soil types are documented.

Reasor, J.A.; Erten-Unal, M.; Drewry, W.A.; Groover, R.T.

1999-07-01

288

Relating changes of organic matter composition of two German peats to climatic conditions during peat formation  

NASA Astrophysics Data System (ADS)

Peatlands have been recognized as an important factor within the global C-cycle, since they store about one-third of the global terrestrial C-pool. Furthermore, peat deposits have the potential to record detailed paleoclimatic and - vegetational changes. They are formed in peculiar paleoecosystems where the slow biodegradation of plant residues depends on a series of pedo-climatic and hydromorphic factors leading to a progressive accumulation of organic matter stabilized in different evolutionary stages. Thus, its chemical composition should be applicable as a fingerprint of former prevailing environmental conditions and vegetation configurations. The aim of the present work was to identify this fingerprint in the cores of two German fens, one derived from the Havelland close to Berlin (Großer Bolchow) and the other derived from the alpine region of Bavaria (Kendlmühlfilzen) by investigating the organic matter transformation as a function of peat depths. The C/N ratios and ?13C values revealed several distinctive trends in the two profiles related to prevailing peat forming conditions. Compared to the other layers, at depths of 14-85 cm and 132-324 cm in the Kendlmühlfilzen fen, high C/N ratios and less depleted ?13C values, indicated that the accumulation of these two layers occurred during a humid and cold period. In the case of the "Großer Bolchow", algal contributions were clearly detected using ?13C values. Solid-state 13C NMR spectroscopy demonstrated loss of celluloses and accumulation of lipids and lignin derivatives during peatification, confirming that under the mostly O2-depleted conditions in peats, decomposition was selective. The results obtained by pyrolysis-GC/MS were in good agreement with the NMR data showing that processes ascribed to gradual biotransformation of the lignin occurred in both peats. However, the "Großer Bolchow" peat revealed a more advanced decomposition stage then the "Kendlmühlfilzen" peat, which is in agreement with less favorable climatic conditions during the formation of the alpine fen. The distribution of n-alkanes, n-fatty acids and n-alkan-2-ones demonstrated changes related to vegetational shifts throughout the peat profiles. The source materials included remains from mosses, higher terrestrial plants as well as microbial sources. In the peat of the "Großer Bolchow", contributions from phytoplankton were also identified. Among the alkyl series, the n-alkanes evidenced the highest reliability as biomarkers in the peat deposits. Although combination of the results of the three alkyl series were complementary, in some cases, this approach lead to ambiguities, possibly because of selective preservation of certain lipids during peatification. Thus, to verify the analytical results, they were supplemented with field assessment data. Subjecting the two peats to CuO-oxidation revealed mainly contributions of mosses and grasses. The analysis of the degradation stage of the lignin derivatives supported the decomposition pattern already revealed by the ?13C data and the NMR analysis. In summary, our study confirmed that in peat, changes in biomarker abundance and distribution are in accordance with chemical alterations of the organic matter composition. However, both biomarker abundance and the degradation state of the organic material did not indicate a constant increase of the humification with peat depths but showed clear fluctuations along the core. This is in line with the constantly changing climatic conditions during peat formation that are either favoring or hindering organic matter accumulation.

Knicker, Heike; Nikolova, Radoslava; Rumpel, Cornelia; González-Vila, Francisco, J.; Drösler, Matthias

2010-05-01

289

Organic Matter Transformation in the Peat Column at Marcell Experimental Forest: Humification and Vertical Stratification  

SciTech Connect

A large-scale ecosystem manipulation (Spruce and Peatland Responses under Climatic and Environmental Change, SPRUCE) is being constructed in the Marcell Experimental Forest, Minnesota, USA, to determine the effects of climatic forcing on ecosystem processes in northern peatlands. Prior to the initiation of the manipulation, we characterized the solid-phase peat to a depth of 2 meters using a variety of techniques, including peat C:N ratios, 13C and 15N isotopic composition, Fourier Transform Infrared (FT IR), and 13C Nuclear Magnetic Resonance spectroscopy (13C NMR). FT IR determined peat humification-levels increased rapidly between and 75 cm, indicating a highly reactive zone. We observed a rapid drop in the abundance of O-alkyl-C, carboxyl-C, and other oxygenated functionalities within this zone and a concomitant increase in the abundance of alkyl- and nitrogen-containing compounds. Below 75-cm, minimal change was observed except that aromatic functionalities accumulated with depth. Incubation studies revealed the highest methane production rates and greatest CH4:CO2 ratios within this and 75 cm zone. Hydrology and surface vegetation played a role in belowground carbon cycling. Radiocarbon signatures of microbial respiration products in deeper porewaters resembled the signatures of dissolved organic carbon rather than solid phase peat, indicating that more recently photosynthesized organic matter fueled the bulk of subsurface microbial respiration. Oxygen-containing functionalities, especially O-alkyl-C, appear to serve as an excellent proxy for soil decomposition rate, and in addition should be a sensitive indicator of the response of the solid phase peat to the climatic manipulation.

Tfaily, Malak [Florida State University, Tallahassee; Cooper, Bill [Florida State University, Tallahassee; Kostka, [Georgia Institute of Technology, Atlanta; Chanton, Patrick R [ORNL; Schadt, Christopher Warren [ORNL; Hanson, Paul J [ORNL; Iversen, Colleen M [ORNL; Chanton, Jeff P [ORNL

2014-01-01

290

Organic matter transformation in the peat column at Marcell Experimental Forest: Humification and vertical stratification  

NASA Astrophysics Data System (ADS)

characterized peat decomposition at the Marcell Experimental Forest (MEF), Minnesota, USA, to a depth of 2 m to ascertain the underlying chemical changes using Fourier transform infrared (FT IR) and 13C nuclear magnetic resonance (NMR) spectroscopy) and related these changes to decomposition proxies C:N ratio, ?13C and ?15N, bulk density, and water content. FT IR determined that peat humification increased rapidly between 30 and 75 cm, indicating a highly reactive intermediate-depth zone consistent with changes in C:N ratio, ?13C and ?15N, bulk density, and water content. Peat decomposition at the MEF, especially in the intermediate-depth zone, is mainly characterized by preferential utilization of O-alkyl-C, carboxyl-C, and other oxygenated functionalities with a concomitant increase in the abundance of alkyl- and nitrogen-containing compounds. Below 75 cm, less change was observed but aromatic functionalities and lignin accumulated with depth. Significant correlations with humification indices, identified by FT IR spectroscopy, were found for C:N ratios. Incubation studies at 22°C revealed the highest methane production rates, greatest CH4:CO2 production ratios, and significant O-alkyl-C utilization within this 30 and 75 cm zone. Oxygen-containing functionalities, especially O-alkyl-C, appear to serve as excellent proxies for soil decomposition rate and should be a sensitive indicator of the response of the solid phase peat to increased temperatures caused by climate change and the field study manipulations that are planned to occur at this site. Radiocarbon signatures of microbial respiration products in deeper pore waters at the MEF resembled the signatures of more modern dissolved organic carbon rather than solid phase peat, indicating that recently photosynthesized organic matter fueled the bulk of subsurface microbial respiration. These results indicate that carbon cycling at depth at the MEF is not isolated from surface processes.

Tfaily, Malak M.; Cooper, William T.; Kostka, Joel E.; Chanton, Patrick R.; Schadt, Christopher W.; Hanson, Paul J.; Iversen, Colleen M.; Chanton, Jeffrey P.

2014-04-01

291

Density and orientation of upland open drains: critical determinants of downstream flood risk?  

NASA Astrophysics Data System (ADS)

Artificial, open drains, known as grips, drain over half of the UK's upland blanket peat area. Despite their hydrological importance, the influence of grips on downstream flood risk is uncertain. Grips lower the water table, thereby increasing the peat's storage capacity; but they also accelerate the delivery of rainfall to the drainage network. It has been hypothesised that the interaction of these competing processes is controlled by grip network density and grip orientation relative to the slope, and that these characteristics are critical determinants of the impact of grips on downstream flood risk. However, the variability of hydrological systems means that conclusions on the particular interactions between discharge, grip density and grip orientation cannot be drawn based purely upon observed correlations. Therefore, this research adopts an experimental numerical modelling approach using a modified version of TOPMODEL that was developed to assess the impacts of grips upon flow hydrographs. Only grip density and orientation were varied in the model, and therefore their relative effects on flow peaks could be assessed. Even with parameter uncertainty, the results indicate that all grip networks, regardless of density or orientation, significantly reduce flow peaks compared to the ungripped case. In general, they also delay the flow peaks. The greatest reductions in flow peaks are seen with increasing grip density and with increasing orientation to the slope. Grip density appears to have a greater influence on discharge than orientation. Increases in both grip density and orientation cause catchment storage capacity to increase, which outweighs the reduced flow travel times. The results have important implications for the current land management practice of grip blocking, which is carried out for ecological benefits.

Coles, A. E.; Milledge, D.; Lane, S. N.

2011-12-01

292

Facilitated legume nodulation, phosphate uptake and nitrogen transfer by arbuscular inoculation in an upland rice and mung bean intercropping system  

Microsoft Academic Search

Intercropping of upland rice with short-duration grain legumes has major advantages in increasing crop yields and soil productivity.\\u000a However, the contribution of arbuscular mycorrhizas, the common mutualistic symbiosis between most crops and mycorrhizal fungi,\\u000a is not fully understood in intercropping systems. We assayed the contribution of inoculation of the arbuscular mycorrhizal\\u000a fungus (AMF) Glomus caledonium on nutrient acquisition and biomass

Yuefeng Li; Wei Ran; Ruiping Zhang; Shubin Sun; Guohua Xu

2009-01-01

293

Saline soils under dryland agriculture in southeastern Saskatchewan (Canada) and possibilities for their improvement  

Microsoft Academic Search

Summary Two experiments to study the effects of organic matter applications on saline soils and crop yields were carried out in a growth room and in the field, respectively. In the growth room experiment peat incorporations improved the yields of barley (fresh weight) over the full range from non-saline to highly saline soils, providing the peat-induced moisture stresses in the

H. Lüken

1962-01-01

294

Soil–Methanogen Interactions in Two Peatlands (Bog, Fen) in Central New York State  

Microsoft Academic Search

Rates of methanogenesis vary widely in peat soils, yet the reasons are poorly known. We examined rates of methanogenesis and methanogen diversity in relation to soil chemical and biological characteristics in 2 peatlands in New York State. One was an acidic (pH < 4.5) bog dominated by Sphagnummosses and ericaceous shrubs, although deeper peat was derived from sedges. The other

Mark D. Dettling; Joseph B. Yavitt; Hinsby Cadillo-Quiroz; Christine Sun; Stephen H. Zinder

2007-01-01

295

ELF communications system ecological monitoring program: Upland flora studies  

NASA Astrophysics Data System (ADS)

The U.S. Navy has completed a program monitoring flora, fauna, and ecological relationships for possible effects from electromagnetic (EM) fields produced by its Extremely Low Frequency (ELF) Communications System. This report documents studies of upland flora conducted near the Navy's transmitting antenna in Michigan. From 1982 through 1993 researchers from the Michigan Technological University (MTU) monitored tree, herb, and fungal species dominant in areas near (treatment) and far (control) from the ELF antenna. Above-ground parameters included the productivity, physiology, and phenology of trees, as well as the morphology and phenology of an herb. Below-ground, the important association between tree roots and fungi were monitored. Investigators also measured ambient weather conditions, soil nutrients, and EM field intensities. The MTU research team used analysis of variance and covariance to examine the data. When site-by-year interactions were significant, correlations and regressions were used to determine whether residuals were related to EM exposure. Results suggest a possible subtle EM effect to the cambial and stemwood growth of some tree species but not to any other parameter. MTU investigators conclude no short-term, adverse effects on forest health from exposure to EM fields produced by the Naval Radio Transmitting Facility-Republic, Michigan.

Mroz, Glenn D.; Cattelino, Peter J.; Gale, Margaret R.; Jones, Elizabeth A.; Jurgensen, Martin F.

1994-10-01

296

Effects of ozone on species composition in an upland grassland.  

PubMed

Northern hemispheric background concentrations of ozone are increasing, but few studies have assessed the ecological significance of these changes for grasslands of high conservation value under field conditions. We carried out a 3-year field experiment in which ozone was released at a controlled rate over three experimental transects to produce concentration gradients over the field site, an upland mesotrophic grassland located in the UK. We measured individual species biomass in an annual hay cut in plots receiving ambient ozone, and ambient ozone elevated by mean concentrations of approximately 4 ppb and 10 ppb in the growing seasons of 2008 and 2009. There was a significant negative effect of ozone exposure on herb biomass, but not total grass or legume biomass, in 2008 and 2009. Within the herb fraction, ozone exposure significantly decreased the biomass of Ranunculus species and that of the hemi-parasitic species Rhinanthus minor. Multivariate analysis of species composition, taking into account spatial variation in soil conditions and ozone exposure, showed no significant ozone effect on the grass component. In contrast, by 2009, ozone had become the dominant factor influencing species composition within the combined herb and legume component. Our results suggest that elevated ozone concentrations may be a significant barrier to achieving increased species diversity in managed grasslands. PMID:22048840

Wedlich, Kerstin V; Rintoul, Naomi; Peacock, Simon; Cape, J Neil; Coyle, Mhairi; Toet, Sylvia; Barnes, Jeremy; Ashmore, Mike

2012-04-01

297

Comparison of different methods to determine the degree of peat decomposition in peat bogs  

NASA Astrophysics Data System (ADS)

Peat humification or decomposition is a frequently used proxy to extract past time changes in hydrology and climate from peat bogs. During the past century several methods to determine changes in peat decomposition have been introduced. Most of these methods are operationally defined only and the chemical changes underlying the decomposition process are often poorly understood and lack validation. Due to the chemically undefined nature of many humification analyses the comparison of results obtained by different methods is difficult if not misleading. In this study we compared changes in peat decomposition in cores of two peat bogs (Königsmoor (KK), Kleines Rotes Bruch, KRB) from the Harz Mountains (Germany) using C / N ratios, Fourier Transform Infrared spectra absorption (FTIR) intensities, Rock Eval® oxygen- and hydrogen indices, ?13C and ?15N isotopic signatures and UV-absorption of NaOH peat extracts. In addition, one of the cores was analysed for changes in the peat's molecular composition using pyrolysis gas chromatography mass spectrometry (pyrolysis-GC-MS). Records of decomposition proxies show similar historical development at both sites, indicating external forcing such as climate as controlling process. Moreover, all decomposition proxies except UV-ABS and ?15N isotopes show similar patterns in their records and thus reflect in different extents signals of decomposition. Pyrolysis-GC-MS analyses of the KK core reveal that changes in peat molecular chemistry are mainly attributed to decomposition processes and to a lesser extend to changes in vegetation. Changes in the abundance of molecular compounds indicate that peat decomposition in the KK bog is mainly characterized by preferential decomposition of phenols and polysaccharides and relative enrichment of aliphatics during drier periods. Enrichment of lignin and other aromatics during decomposition was also observed but showed less variation, and presumably reflects changes in vegetation associated to changes in hydrology of the bogs. Significant correlations with polysaccharide and aliphatic pyrolysis products were found for C / N ratios, FTIR-band intensities and for hydrogen index values, supporting that these decomposition indices provide reasonable information despite their bulk nature. Correlation with oxygen index values and ?13C was weaker assumingly indicating carboxylation of the peat during drier periods and enrichment of isotopically lighter peat components during decomposition, respectively. FTIR, C / N ratio, Pyrolysis-GC-MS analyses and Rock Eval hydrogen indices appear to reflect mass loss and related changes in the molecular peat composition during mineralization best. Different to the other investigated proxies, Pyrolysis-GC-MS and FTIR analyses allow disentangling decomposition processes and vegetation changes. UV-ABS measurements of alkaline peat extracts show only weak correlation with other decomposition proxiesas they mainly reflect the formation of humic acids through humifcation and to a~lesser extend mass loss during mineralization.

Biester, H.; Knorr, K.-H.; Schellekens, J.; Basler, A.; Hermanns, Y.-M.

2013-11-01

298

Upland habitat conservation in Scotland: a review of progress and some proposals for action  

Microsoft Academic Search

The uplands cover around 70% of Scotland's land surface. Many of the extensive and well-developed habitats are internationally distinctive in their floristics. Almost 250 Sites of Special Scientific Interest are designated primarily for upland habitat interests, and there are 23 upland National Nature Reserves. The EC Habitats Directive lists 23 ‘natural habitat’ types found in the Scottish uplands. More than

D. B. A. Thompson; D. Horsfield

1997-01-01

299

Effects of water management on arsenic and cadmium speciation and accumulation in an upland rice cultivar.  

PubMed

Pot and field experiments were conducted to investigate the effects of water regimes on the speciation and accumulation of arsenic (As) and cadmium (Cd) in Brazilian upland rice growing in soils polluted with both As and Cd. In the pot experiment constant and intermittent flooding treatments gave 3-16 times higher As concentrations in soil solution than did aerobic conditions but Cd showed the opposite trend. Compared to arsenate, there were more marked changes in the arsenite concentrations in the soil solution as water management shifted, and therefore arsenite concentrations dominated the As speciation and bioavailability in the soil. In the field experiment As concentrations in the rice grains increased from 0.14 to 0.21mg/kg while Cd concentrations decreased from 0.21 to 0.02mg/kg with increasing irrigation ranging from aerobic to constantly flooding conditions. Among the various water regimes the conventional irrigation treatment produced the highest rice grain yield of 6.29tons/ha. The As speciation analysis reveals that the accumulation of dimethylarsinic acid (from 11.3% to 61.7%) made a greater contribution to the increase in total As in brown rice in the intermittent and constant flooding treatments compared to the intermittent-aerobic treatment. Thus, water management exerted opposite effects on Cd and As speciation and bioavailability in the soil and consequently on their accumulation in the upland rice. Special care is required when irrigation regime methods are employed to mitigate the accumulation of metal(loid)s in the grain of rice grown in soils polluted with both As and Cd. PMID:25597681

Hu, Pengjie; Ouyang, Younan; Wu, Longhua; Shen, Libo; Luo, Yongming; Christie, Peter

2015-01-01

300

Structurally bound lipids in peat humic acids  

Microsoft Academic Search

Humic acids from highly decomposed peat were subjected to oxidation with alkaline cupric oxide (CuO) at 170°C (single oxidation). Oxidation products were isolated as three fractions, oxidized humic acids, fulvic acids and lipophilic compounds. Isolated oxidized humic acids were subsequently re-oxidized (sequential oxidation) under the same conditions, and released lipophilic compounds were isolated. Lipids released during single and sequential oxidations

Keijo Lehtonen; Kari Hänninen; Martti Ketola

2001-01-01

301

Spatial Distribution of Soil Nutrients in a Northern Everglades Marsh: Water Conservation Area 2A  

E-print Network

Spatial Distribution of Soil Nutrients in a Northern Everglades Marsh: Water Conservation Area 2A W of P, N, C, and related physico-chemical parameters in the peat soils (Histosols) of Water Conservation

Florida, University of

302

Peat decomposition in a transitional mire in central Poland  

Microsoft Academic Search

The goal of our work was to estimate the rate of the peat formation and mineralization at two depths: 30 cm (the aerobic zone)\\u000a and 60 cm (the anaerobic zone). An experiment on peat incubation was performed for two years. In the first year, at the depth\\u000a of 30 cm, the peat lost about 14% of its mass in the

A. A. Titlyanova; S. V. Shibareva; P. Bienkowski

2011-01-01

303

Soil Core Sample #1  

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.  The buried layer of peat beneath goose grazing lawn demonstrates that vegetation change has occurred in this area....

304

Modelling UK upland peatland carbon dynamics - past, present and future  

NASA Astrophysics Data System (ADS)

Current global soil organic carbon (SOC) models are insufficient in modelling C dynamics in peatlands. Over the last 10k years (i.e. Holocene) large amounts of SOC built up in northern hemisphere peatlands during a variable climate with major vegetation changes. However, peatland SOC stocks foster a great potential for both either sequestering or releasing large amounts of C to the atmosphere. As such, understanding their carbon dynamics is fundamental for underpinning better model predictions on their potential role in atmospheric C-cycling and climate feedbacks, specifically considering their role in global methane fluxes. A fundamental shortfall in current models is the lack of accurate water table representation, affecting decomposition and methane fluxes to the atmosphere. Moreover, existing major SOC models do not adequately: (i) allow a long-term ‘spin-up' accumulation of SOC based on a variable ‘real' past climate and vegetation during the Holocene, (ii) reflect dynamic changes in SOC affecting hydrology and bulk density, nor (iii) consider hydrological impacts (i.e. water table changes) and its influence on plant communities, litter quality and biological activity and effects on C input and decomposition. In the MILLENNIA peatland model, carbon turnover is linked to dynamic changes in hydrology and litter quality, particularly considering water table dynamics and its effects on decomposition. We present preliminary MILLENNIA peatland model runs for the UK modelling SOC stocks, accumulation rates and turnover rates in blanket peatlands commonly found in UK uplands and compare them to field measurements: (1) We propose an improved litter cohort-based model approach for peatland carbon dynamics, taking account of long-term (Holocene) dynamics in soil physical (e.g. water table), chemical (e.g. litter quality) and biological (plant functional types) factors and their effects on carbon turnover. (2) We use a simple, but well established, regression based approach for estimating net primary productivity (NPP) and decomposition based on actual evapotranspiration (AET) and consider water table effects on plant functional type composition. (3) We consider the conceptual issues that soil C is commonly ‘spun up' to a preset C content equilibrium, using a static climate and vegetation, before running real C simulations including a reconstructed Holocene climate in our model to accumulate soil C over ~10k since the last glaciation. We also discuss implementations of other factors affecting carbon build-up in peatlands, such as runoff and effects of aspect and slope. Moreover, results include linking carbon flux predictions (including methane) to the model's intrinsic hydrology and water table dynamics.

Heinemeyer, Andreas; Croft, Simon; Lomas, Mark R.; Garnett, Mark H.; Ineson, Phil

2010-05-01

305

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

USGS Publications Warehouse

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

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

1987-01-01

306

Carbon release from Sphagnum peat during thawing in a montane area in China  

NASA Astrophysics Data System (ADS)

Soil thawing may affect the turnover of soil organic carbon (C) and the release of C to the atmosphere. Little is known about C release during thawing in the Great Hing'an Mountains, China. Through the incubations, we studied the emissions of CO2 and CH4 during thawing from the Sphagnum moss layer to the permafrost layer under aerobic and anaerobic conditions. Carbon was released quickly during thawing under different conditions. The Sphagnum moss layer produced more CO2 than the other layers. However, there was little CH4 release during thawing in the Sphagnum moss layer and burst of CH4 emissions in the peat and permafrost soils. These bursts include stored CH4 in the frozen samples and productions from microbial activity. The temperature sensitivity during thawing decreased across the freezing point in the Sphagnum moss layer, did not change greatly in the root layer, and increased greatly in the peat and permafrost layers. Changes in soil substrates and enzyme activities may affect C release during thawing.

Wang, Xianwei; Song, Changchun; Wang, Jiaoyue; Miao, Yuqing; Mao, Rong; Song, Yanyu

2013-08-01

307

Impacts of livestock in regenerating upland birch woodlands in Scotland   

E-print Network

Including large herbivores in wooded areas is often seen as a useful conservation tool. Browsing intensities on saplings in seven upland birch woodlands grazed by sheep, cattle and wild herbivores were studied. The aims ...

Pollock, Meg L; Milner, J M; Waterhouse, A; Holland, J P; Legg, Colin

2005-01-01

308

Arizona Upland Plant Community in the Sonoran Desert  

USGS Multimedia Gallery

In the drier Arizona upland plant communities, pictured here, some species will likely decline with forecasted climate change (such as foothill paloverde, ocotillo and creosote bush) while cacti may well increase in abundance and range....

309

Continuous cover forestry: possible implications for surface water acidification in the UK uplands  

NASA Astrophysics Data System (ADS)

The effects of widespread conifer afforestation on the acidity of lakes and streams in the acid sensitive uplands of the UK has been researched extensively and has contributed to the development and implementation of national forest management guidelines (e.g. Forest and Water Guidelines; Forestry Commission, 1993). However, a recent policy document (Woodlands for Wales; National Assembly for Wales, 2000) has proposed a major shift in the management of 50% of the Forestry Commission estate in Wales from the current system of patch clearfelling to Continuous Cover Forestry (CCF). This scale of change is without precedent in the UK; no studies in the UK forest environment have examined the likely environmental impacts of CCF. However, the wealth of environmental data from studies of UK forests managed by patch clearfelling enables an assessment of the impact of a change to CCF on three issues of particular relevance to surface water acidification in the uplands; forest harvesting, soil base cation depletion and atmospheric pollutant deposition. Whilst there is uncertainty as to how even-aged stands will be transformed to CCF in the UK, guiding principles for CCF on acidic and acid sensitive sites should focus on those aspects of management which minimise nitrate leaching, encourage base cation retention within the soil-plant system and enhance base cation inputs from external (atmospheric) and internal sources (weathering). CCF may provide opportunities to achieve this by reducing the scale of clearfelling, increasing species diversity, changing the structure of plantation forests and maintaining uninterrupted woodland cover.

Reynolds, B.

310

[Nutrient management strategy of paddy rice-upland crop rotation system].  

PubMed

Paddy rice-upland crop rotation system is a major cropping system in China, and practiced widely along the Yangtze River basin. A unique feature of this system is the annual conversion of soil from aerobic to anaerobic and then back to aerobic condition, which can result in the changes of soil physical, chemical, and biological prosperities among seasons, making a special agroecosystem. The major challenges faced by this system include declining or stagnating productivity, increasing shortage of irrigation water, improper management of nutrients, low efficiency of resource utilization, and environmental pollution. Based on an overview of the characteristics and problems of paddy rice-upland crop rotation system, this paper put forward a strategy of practicing integrated nutrient management to solve the contradictions between nutrient input, crop production and environmental risk. The key points of this strategy included nutrient management from the whole rotation system perspective, integrated use of nutrients from various sources (chemical fertilizers, organic fertilizers, and nutrients from the environment), synchronization of nutrient supply and crop nutrient demand, application of different management technologies based on the characteristics of different nutrient resources, and integration of nutrient management with other cropping system technologies like water saving and high-yielding cultivation, etc. PMID:18472447

Fan, Ming-Sheng; Jiang, Rong-Feng; Zhang, Fu-Suo; Lü, Shi-Hua; Liu, Xue-Jun

2008-02-01

311

Responses of Isolated Wetland Herpetofauna to Upland Forest Management  

SciTech Connect

Measurement of responses of herpetofauna at isolated wetlands in the Coastal Plain of South Carolina to disturbance of adjacent loblolly pine forest. Many species of isolated wetland herpetofauna in the Southeastern Coastal Plain may tolerate some disturbance in adjacent upland stands. Responses of isolated wetland herpetofauna to upland silviculture and the need for adjacent forested buffers likely depend on the specific landscape context in which the wetlands occur and composition of the resident herpetofaunal community.

Russell, K.R.; Hanlin, H.G.; Wigley, T.B.; Guynn, D.C., Jr.

2002-01-02

312

Slurry-comp, a new method for fuel peat production  

SciTech Connect

Peat is mainly used in Finland for energy production. About 5 % of Finland`s present energy consumption is fulfilled by peal Peat is normally produced with methods based on solar energy, i.e. peat is dried on open fields. These methods are not feasible in Northern Finland where solar radiation is not intensive enough. Alternative production methods based on so-called artificial (mechanical) dewatering have been studied in many countries, including Finland, over the recent years. In Finland a research program called {open_quotes}The Artificial Dewatering of Peat{close_quotes} (ADEWA) has been in progress during 1988-92, the total funding being approved USD 2 million. In the ADEWA research programme a new peat production method, called SLURRY-COMP, has been developed. In this production process, peat, after having been slurried to a dry solids content of about 7%, is pumped from the slurrying basin into a large storage pond located near the power plant, and after that passed through a mechanical dewatering process. The dewatered peat, with a moisture content of about 60 - 65%, can be burned in pressurized combustion or, after some thermal drying, in traditional combustion chambers. In the process concept, the total peat production is 400,000 metric tons of dry solids per year, which equals the fuel demand for a power plant of about 150 - 200 MW electric power. One of the aims of the studies carried out at the Technical Research Centre of Finland has been to obtain enough reliable information for the optimization of long distance pumping of peat slurry. In addition to peat type, the mining and slurrying technique (determining the particle size), pipe diameter, and flow velocity also have a great influence on the flowing properties and pressure losses of peat slurry.

Luukkainen, V.M. [Combustion and Thermal Engineering Lab., Jyvaskyla (Finland)

1993-12-31

313

Tracing origin and fate of dissolved greenhouse gases in Malaysian peat-draining rivers  

NASA Astrophysics Data System (ADS)

Tropical peatlands are known to store large amounts of organic carbon. Peat-draining rivers in these regions receive considerable amounts of carbon from these soils, yet, its fate remains poorly studied. Although a number of recent studies investigated greenhouse gas production and emission from inland waters, only a small number focused on tropical freshwaters, and data from tropical peat-draining rivers are particularly lacking. We investigated rivers in a peat-dominated catchment in Sarawak, Malaysia. Dissolved greenhouse gases (GHG) were measured with Fourier Transform InfraRed (FTIR) spectroscopy. It allows for the simultaneous and continuous measurement of major GHG (CO2 and ?13C in CO2, CH4, N2O, and CO) with high accuracy and precision. We found that concentrations of dissolved CO, CO2 and CH4 were higher than the respective atmospheric equilibrium concentration, suggesting that those rivers are a source of these GHG to the atmosphere. Enhanced N2O concentrations were only found around some cultivated areas. In order to trace the origin of the GHG, we quantified dissolved organic carbon (DOC), particulate organic carbon (POC), inorganic nutrients and different parameters that describe water chemistry. Stable carbon isotope analysis of dissolved inorganic carbon (DIC) yielded indications of a terrestrial source of inorganic carbon in the river, suggesting that in-situ respiration of organic matter might play an important role.

Müller, Denise; Warneke, Thorsten; Rixen, Tim; Denis, Nastassia; Müller, Moritz; Notholt, Justus

2014-05-01

314

Sulfur contents of peats at the confluence of carbonate and peat-forming depositional systems, southeastern Florida  

SciTech Connect

Complex stratigraphic and compositional relationships have been reported by others at sites where coal beds are laterally in contact with marine carbonates (such as in the southern portion of the Illinois basin). These basin edges are important in that they may (1) represent sites of active coal mining, (2) contain important clues as to the development of the basin, and (3) be sources of the dispersed terrestrial organics encountered in nearby marine rocks. This study was undertaken to investigate peat/carbonate relationships in a modern setting, with initial research on sulfur contents relative to stratigraphic/petrographic conditions. Thirty-eight cores were taken along northwest-southeast transects from the mainland to Florida Bay. The most inland cores consist entirely of peat, representing transgression of marine types (mangrove) over freshwater types. Toward the carbonate-rich bay, a more complex stratigraphy exists. Marine carbonates and peats interfinger, with erosional contacts indicating that parts of the peat sequence are missing. At the coastline, most of the peat is replaced by marine carbonate except for thin (1-10 cm) basal (usually overlain by marine carbonates), with the best preserved ranges from 0.6 to 5.0% (dry) at the most inland sites, 2.4 to 7.8% near the coastline, and 1.5 to 5.9% in bay sediments. Total sulfur is higher in marine than freshwater peats, but freshwater peats overlain by marine peats are enriched in sulfur. Freshwater peats beneath marine carbonates are relatively low in sulfur, but are higher if the peat is overlain by a marine peat before being overlain by the carbonate.

Cohen, A.D. (Univ. of South Carolina, Columbia, SC (United States)); Davies, T.D. (Exxon Exploration Co., Houston, TX (United States)); Spackman, W. (Pennsylvania State Univ., University Park, PA (United States))

1993-08-01

315

Peat: A Natural Source for Dermatocosmetics and Dermatotherapeutics  

PubMed Central

In recent years the interest for natural substances in dermatotherapy and cosmetics has increased. Peat is a complex natural source of humic substances that are of potential interest in both dermatology and cosmetology. Humic substances in peat have been partially characterized and pharmacologic and biologic activities have been documented. Possible clinical applications are outlined. PMID:20300366

Wollina, Uwe

2009-01-01

316

Restoring peat-accumulating function on cutaway peatlands  

Microsoft Academic Search

Summary In order to focus restoration efforts towards specific vegetation groups in fen restoration, knowledge of the peat-accumulating potential of dominant fen species is critical. Historical information (macrofossil analyses) was examined and summarised to characterise fen peat of North American boreal peatlands. Cyperaceae and Sphagnum species were found to be important vegetation groups for accumulating organic matter. Addition - ally,

Martha Graf; Line Rochefort

317

State of Michigan peat resource estimation. Volume 1. Final report  

SciTech Connect

This report contains the results of an inventory of the peat resources of Michigan conducted as part of the DOE Peat Program. Approximately 200 deposits were sampled from the Upper Peninsula and from two counties in the Lower Peninsula; 1248 samples were collected and analyzed for selected energy-related properties. A reconnaissance survey was done in the Lower Peninsula to provide the most accurate estimate possible within project constraints. These results provide a solid foundation for subsequent inventories. The fuel-grade peat resource in Michigan is estimated to be approximately 1.64 billion tons, and to contain 26.2 quads (10/sup 15/ Btu) of energy. Approximately 46% of Michigan's fuel-grade resource occurs in the Upper Peninsula. The Lower Peninsula estimate was based on a smaller sampling of deposits and further study may reduce this resource estimate. The peat deposits in Michigan are generally small compared to those in Minnesota and Maine, but have proven to be suitable for utilization by the horticultural peat industry. A similar pattern of use of this material for energy production may occur in the future. According to DOE criteria for ash and calorific value, the peat materials in the Upper Peninsula are generally suited for energy use. There are differences in peat quality between geographic regions. The peat materials sampled from five counties in the more populated areas of the Lower Peninsula are more decomposed, contain more ash, and less energy. 33 refs.

LeMasters, G.S.; Jones, E.A.

1984-01-30

318

Biochar as a growing media additive and peat substitute  

NASA Astrophysics Data System (ADS)

Environmental concerns raised the demand for alternative growing media substituting Sphagnum peat. However growing media formulations still depend on peat and alternatives are limited. Biochar is carbonized plant material and could be an appropriate additive or even substitute for Sphagnum peat. Freshly produced, it is free from pathogens, has a low nutrient content (if produced from nutrient-poor feedstock), a very high structural stability and likely other favourable properties such as air capacity and water-holding capacity. Preliminary tests were conducted to compare biochar with other growing media and growing media additives. The growth of a miniature sunflower, pH and electrical conductivity (EC) was measured in different growing media such as biochar, perlite, clay granules, Sphagnum peat and peat mixed with biochar in the ratios 1 : 4, 1 : 1 and 4 : 1 (25, 50 and 75%, by volume). Fresh biochar has a similar EC to peat which is even lower after rinsing with water. Due to the relatively high pH of biochar, it could be added to peat instead of lime in a concentration of up to 75%. The growth of the sunflower was similar in all growing media. Only the plant weight was slightly higher of plants that grew in perlite or peat. There is a large potential for optimization such as selection of particle size and feedstock for biochar production and growing media formulations for specific plant requirements.

Steiner, C.; Harttung, T.

2014-09-01

319

The preparation of testate amoebae (Protozoa: Rhizopoda) samples from peat  

Microsoft Academic Search

The analysis of testate amoebae (Protozoa: Rhizopoda) in peat is proving to be a useful new quantitat ive technique for assessing hydrological change on peatlands. Preparation experiments were carried out on peat extracted from Coom Rigg Moss, Northumberland, England, in order to assess the impact of different procedures on the concentration and species composition of the faunas. Five replicates of

Dawn Hendon; Daniel J. Charman

1997-01-01

320

PEAT ACCRETION HISTORIES DURING THE PAST 6000 YEARS IN MARSHES OF THE SACRAMENTO - SAN JOAQUIN DELTA, CALIFORNIA, USA  

SciTech Connect

Peat cores were collected in 4 remnant marsh islands and 4 drained, farmed islands throughout the Sacramento - San Joaquin Delta of California in order to characterize the peat accretion history of this region. Radiocarbon age determination of marsh macrofossils at both marsh and farmed islands showed that marshes in the central and western Delta started forming between 6030 and 6790 cal yr BP. Age-depth models for three marshes were constructed using cubic smooth spline regression models. The resulting spline fit models were used to estimate peat accretion histories for the marshes. Estimated accretion rates range from 0.03 to 0.49 cm yr{sup -1} for the marsh sites. The highest accretion rates are at Browns Island, a marsh at the confluence of the Sacramento and San Joaquin rivers. Porosity was examined in the peat core from Franks Wetland, one of the remnant marsh sites. Porosity was greater than 90% and changed little with depth indicating that autocompaction was not an important process in the peat column. The mean contribution of organic matter to soil volume at the marsh sites ranges from 6.15 to 9.25% with little variability. In contrast, the mean contribution of inorganic matter to soil volume ranges from 1.40 to 8.45% with much greater variability, especially in sites situated in main channels. These results suggest that marshes in the Delta can be viewed as largely autochthonous vs. allochthonous in character. Autochthonous sites are largely removed from watershed processes, such as sediment deposition and scour, and are dominated by organic production. Allochthonous sites have greater fluctuations in accretion rates due to the variability of inorganic inputs from the watershed. A comparison of estimated vertical accretion rates with 20th century rates of global sea-level rise shows that currently marshes are maintaining their positions in the tidal frame, yet this offers little assurance of sustainability under scenarios of increased sea-level rise in the future.

Drexler, J Z; de Fontaine, C S; Brown, T A

2009-07-20

321

Ecological assessment for the wetlands at Milltown Reservoir, Missoula, Montana: Characterization of emergent and upland habitats  

SciTech Connect

Wetlands in mining districts in the western US are frequently impacted by heavy metal-contaminated sediments. The present study summarizes a soil contamination evaluation and an ecological assessment completed for a Superfund site located at Milltown Reservoir wetlands (MRW) in western Montana. For wetlands, as well as upland habitats adjacent to wetlands, biological evaluations in the field and laboratory should be considered critical components in the ecological risk assessment process. Depending upon habitat type, field and laboratory methods have been developed for hazard and risk assessment that lend themselves directly to the Superfund ecological risk assessment process, and that consider contaminant bioavailability and subtle expressions of adverse biological effects associated with chronic exposures. As part of an ecological risk assessment for MRW, field surveys and a variety of biological test methods (e.g., terrestrial and aquatic tests) were critical to the wetland evaluation. For evaluating heavy metal effects at MRW, field and laboratory methods within the ecological assessment included wetlands delineation and preliminary plant and wildlife survey; vegetation tests in emergent and upland habitats; soil macroinvertebrate (earthworm) tests; preliminary studies using amphibian and bacterial test systems; soil characterizations; and chemical analysis of soils, sediments, and biological materials. Inn conjunction with chemical analyses, these biological and ecological evaluations yielded an integrated evaluation of ecological effects and exposure at MRW. The data gathered from laboratory and field work at MRW suggested that biological and ecological effects were subtle in their expression in the wetland. In conjunction with sediment contamination evaluations, these studies should reduce the uncertainty associated with the baseline ecological risk assessment for MRW.

Linder, G. (HeronWorks Farm, Salem, OR (United States)); Hazelwood, R.; Palawski, D. (Fish and Wildlife Service, Helena, MT (United States). Ecological Services) (and others)

1994-12-01

322

The efficiency of turn-over processes in degraded peat as investigated under continuous flow conditions  

NASA Astrophysics Data System (ADS)

Nitrate removal from run-off from agricultural land is in general required to reach a "good chemical status" of surface and groundwater bodies according to the European Water Framework Directive. Removing nitrates via heterotrophic denitrification is highly effective but requires stable anoxic environmental conditions as well as available organic carbon as an electron donator. Constructed wetlands, established on peat soils, through which the nitrate-loaded water is routed, may provide denitrification favorable conditions. A long-term flow experiment (mesocosm) was conducted employing a laboratory container set-up filled with decomposed peat aiming at quantifying the nitrate removal efficiency at various nitrate influx rates. The redox potential was measured at different depths to determine the spatial distribution of denitrificating zones. This new methodological approach allows the observation of biological nitrate turn over without interrupting the adjusted flow rate. We investigated the hydraulic properties and derived transport parameters for the mesocosm by analyzing experimental data from tracer tests. The obtained bromide breakthrough curves (BTC) were subjected to model analysis using the CXTFIT routine of the STANMOD software package. It could be demonstrated that the degraded peat has a dual porosity structure with roughly 40% of the pore water not participating in convective flow and transport processes. Further, the first flushing of mineralized nitrate upon rewetting and onset of flux may compromise any positive clean-up and nitrate removal effects occurring during long-term operation of peat wetlands. The development of the spatial sequence of bacterial cultures is characterized by the redox potential. It is dominated by the available substrates that serve as electron acceptors in bacterial respiration and occurs in a thermodynamically determined top-down order. The zonal development of the nitrate-consuming bacteria was observed and used to describe the removal efficiency of the mesocosm.

Kleimeier, Christian; Karsten, Ulf; Janssen, Manon; Lennartz, Bernd

2013-04-01

323

Burned and unburned peat water repellency: Implications for peatland evaporation following wildfire  

NASA Astrophysics Data System (ADS)

Water repellency alters soil hydrology after periods of wildfire, potentially modifying the ecosystem recovery to such disturbance. Despite this potential importance, the extent and severity of water repellency within burned peatlands and its importance in regulating peatland recovery to wildfire disturbance remains poorly understood. We characterised the water repellency of peat in a burned (one year post-fire) and unburned peatland in the Western Boreal Plain utilising the water drop penetration time and ethanol droplet molarity tests. Burned Sphagnum moss and feather moss sites had a more severe degree of water repellency than unburned sites, with differences being more pronounced between burned and unburned feather moss sites. Burned feather moss exhibited the most extreme water repellency, followed by unburned feather moss, and burned Sphagnum. The severity of water repellency varied with depth through the near surface of the moss/peat profile. This was most evident within the burned feathermoss where more extreme water repellency was observed at the near-surface compared to the surface, with the most extreme water repellency found at 1 and 5 cm depths. Unburned Sphagnum was completely hydrophilic at all depths. We suggest that the extreme water repellency in near-surface feather moss peat acts as a barrier that impedes the supply of water to the surface that replaces that lost via evaporation. This leads to drying of the near-surface vadose zone within feather moss areas and a concomitantly large decrease in peatland evaporation within feather moss dominated peatlands. This negative feedback mechanism likely enhances the resilience of such peatland to wildfire disturbance, maintaining a high water table position, thereby limiting peat decomposition. In comparison, such a feedback is not observed strongly within Sphagnum, leaving Sphagnum dominated peatlands potentially vulnerable to low water table positions post disturbance.

Kettridge, N.; Humphrey, R. E.; Smith, J. E.; Lukenbach, M. C.; Devito, K. J.; Petrone, R. M.; Waddington, J. M.

2014-05-01

324

Isotopic evidence for nitrogen mobility in peat bogs  

NASA Astrophysics Data System (ADS)

Elevated nitrogen (N) input may reduce carbon (C) storage in peat. Under low atmospheric deposition, most N is bound in the moss layer. Under high N inputs, Sphagnum is not able to prevent penetration of dissolved N to deeper peat. Nitrogen may become available to the roots of invading vascular plants. The concurrent oxygenation of deeper peat layers, along with higher supply of labile organic C, may enhance microbial decomposition and lead to peat thinning. The resulting higher emissions of greenhouse gases may accelerate global warming. Seepage of N to deeper peat has never been quantified. Here we present evidence for post-depositional mobility of atmogenic N in peat, based on natural-abundance N isotope ratios. We conducted a reciprocal peat transplant experiment between two Sphagnum-dominated peat bogs in the Czech Republic (Central Europe), differing in anthropogenic N inputs. The northern site VJ received as much as 33 kg N ha-1 yr-1 via spruce canopy throughfall. The southern site was less polluted (17.6 kg N ha-1 yr-1). Isotope signatures of living moss differed between the two sites (?15N of -3‰ and -7‰ at VJ and CB, respectively). After 18 months, an isotope mass balance was constructed. In the CB-to-VJ transplant, a significant portion of original CB nitrogen (98-31%) was removed and replaced by nitrogen of the host site throughout the top 10 cm of the profile. Nitrogen, deposited at VJ, was immobilized in imported CB peat that was up to 20 years old. Additionally, we compared N concentration and N accumulation rates in 210Pb-dated peat profiles with well-constrained data on historical atmospheric N pollution. Nationwide N emissions peaked in 1990, while VJ exhibited the highest N content in peat that formed in 1930. This de-coupling of N inputs and N retention in peat might be interpreted as a result of translocation of dissolved pollutant N downcore, corroborating our ?15N results at VJ and CB. Data from a variety of peat bogs along pollution and climatic gradients would be needed to test to what extent the record of atmospheric N inputs in peat is overprinted by variable, locally-controlled decomposition rates.

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

2014-05-01

325

Possibilities for detailed dating of peat bog deposits  

SciTech Connect

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

Punning, J.; Ilomets, M.; Koff, T. (Inst. of Ecology and Marine Research, Tallinn (Estonia))

1993-01-01

326

Relationships between soil microbial communities and soil carbon turnover along a vegetation and moisture gradient in interior Alaska  

NASA Astrophysics Data System (ADS)

Boreal landscapes are characterized by a mosaic of uplands and lowlands, which differ in plant species composition, litter biochemistry, and biogeochemical cycling rates. Boreal ecosystems, from upland black spruce stands to lowland fens, are structured largely by water table position and contain quantitatively and qualitatively different forms of soil organic matter. Differences in carbon (C) availability among ecosystems likely translate to differences in the structure of soil microbial communities, which in turn could affect rates of organic matter decomposition and turnover. We examined relationships between microbial communities and soil C turnover in near-surface soils along a topographic soil moisture and vegetation gradient in interior Alaska. We tested the hypothesis that upland black spruce sites would be dominated by soil fungi and have slow rates of C turnover, whereas lowland ecosystems would be dominated by bacteria and mesofauna (enchytraeids) and have more rapid rates of C turnover. We utilized several isotopic measures of soil C turnover including bomb radiocarbon techniques, the ?15N of SOM, and the difference between ?13C of SOM, DOC, and respired CO2. All three measures indicated greater C turnover rates in the surface soils of the lowland fen sites compared to the more upland locations. Quantitative PCR analyses of soil bacteria and archaea, combined with enchytraed counts, confirmed that surface soils from the lowland fen ecosystems had the highest abundances of these functional groups. Fungal biomass was highly variable and tended to be more abundant in the upland forest sites. Soil enzymatic results were mixed: potential cellulase activities were higher in the more upland soils even though rates of microbial activity were generally lower. Oxidative enzyme activities were higher in fens, even though these ecosystems are saturated and partly anaerobic. Overall our data support soil food web theory which argues that rapidly cycling systems are bacterial dominated with mesofaunal grazing, whereas slowly cycling systems have characteristic higher fungal:bacterial ratios.

Waldrop, M. P.; Harden, J. W.; Turetsky, M. R.; Petersen, D. G.; McGuire, A. D.; Briones, M. J.; Churchill, A. C.; Doctor, D. H.; Pruett, L. E.

2010-12-01

327

Respiration fluxes in a paludified shallow-peat spruce forest in the southern taiga of European Russia  

NASA Astrophysics Data System (ADS)

Soil, tree stems and ecosystem carbon dioxide fluxes were measured by chambers and eddy covariance methods in paludified shallow-peat spruce forest in southern taiga of European Russia (Tver region, 56N 33E) during growing seasons of 2002 - 2012. The site was established in 1998 as part of the EUROSIBERIAN CARBONFLUX project, an international field experiment examining atmosphere-biosphere interaction in Siberia and European Russia. In all of the years the observed annual cumulative net ecosystem flux was positive (the forest was a source of carbon to the atmosphere). Soil and tree stem respiration was a significant part of total ecosystem respiration (ER) in this paludified shallow-peat spruce forest. On average, 49% of ER came from soil respiration. We found that the soil fluxes exhibited high seasonal variability ranging from 0.7 to 10 mkmol m-2s-1. Generally soil respiration depended on soil temperature and ground water level. In drought conditions soil respiration was low and did not depend on temperature. Stem respiration of spruces grew intensively in May, had permanently high values from June to the end of September and in October it dramatically decreased. Tree stem respiration in midsummer was about 3-5 mkmol•m-2s-1 for dominant trees and about 1-2 mkmol•m-2s-1 for subdominant trees. Respiration of living tree stems was about 10-20% of ER.

Kurbatova, Juliya

2014-05-01

328

Partitioning of ecosystem respiration in a paludified shallow-peat spruce forest in the southern taiga of European Russia  

NASA Astrophysics Data System (ADS)

Soil, tree stems, and ecosystem carbon dioxide fluxes were measured by chambers and eddy covariance methods in a paludified shallow-peat spruce forest in the southern taiga of European Russia (Tver region, 56° N 33° E) during the growing seasons of 2002-2012. The site was established in 1998 as part of the EUROSIBERIAN CARBONFLUX project, an international field experiment examining atmosphere-biosphere interaction in Siberia and European Russia. In all years the observed annual cumulative net ecosystem flux was positive (the forest was a source of carbon to the atmosphere). Soil and tree stem respiration was a significant part of the total ecosystem respiration (ER) in this paludified shallow-peat spruce forest. On average, 49% of the ER came from soil respiration. We found that the soil fluxes exhibited high seasonal variability, ranging from 0.7 to 10 ?mol m-2 s-1. Generally, the soil respiration depended on the soil temperature and ground water level. In drought conditions, the soil respiration was low and did not depend on temperature. The stem respiration of spruces grew intensively in May, had permanently high values from June to the end of September, and in October it dramatically decreased. The tree stem respiration in midsummer was about 3-5 ?mol m-2 s-1 for dominant trees and about 1-2 ?mol m-2 s-1 for subdominant trees. The respiration of living tree stems was about 10-20% of the ER.

Kurbatova, J.; Tatarinov, F.; Molchanov, A.; Varlagin, A.; Avilov, V.; Kozlov, D.; Ivanov, D.; Valentini, R.

2013-12-01

329

Organic matter dynamics control plant species coexistence in a tropical peat swamp forest  

PubMed Central

We studied the relationship between the coexistence of tree species and the dynamics of organic matter in forests. A tropical peat swamp forest was selected as a model ecosystem, where abiotic factors, such as geological topography or parent rock types, are homogeneous and only biological processes create habitat heterogeneity. The temporal or spatial variation of the ground elevation of peat soils is mainly caused by changes in the balance between organic matter inputs to soils and decomposition, which is affected by the growth and death of influential trees. To clarify the processes of elevation dynamics, we measured the microtopography around some tree groups, estimated organic matter (in the form of litter and roots) in soils under three kinds of microtopographic conditions, measured decomposition rates and detected dominant species' shifting distribution patterns in different stages of growth in relation to the locations of tree groups creating specific microtopographic conditions. We found that growth or death of buttressed trees has the greatest effects on the rising or sinking of ground surfaces through changes in litter supply and root production. We discuss here the possibility of extending our model to other forest types. PMID:16011926

Shimamura, Tetsuya; Momose, Kuniyasu

2005-01-01

330

Peat resources of southern and western Maine. [USA  

SciTech Connect

Peat has been used for many years in agriculture and horticulture primarily because of its ability to retain many times its own weight in water. It has also been used as a domestic fuel for hundreds of years. More recently, peat has been used by nations such as Ireland and the Soviet Union to generate electricity. At the present time, virtually all of the peat harvested in the United States is used in agriculture and horticulture. However, in light of the increasing costs of traditional energy sources, peat is being more closely scrutinized as an alternate fuel source. The State of Maine has significant peat resources, and current estimates suggest that there are as many as 6000 to 8000 individual peat deposits comprising a total land area of 500,000 to 750,000 acres. The current resource evaluation was developed to provide a more comprehensive analysis of available peat resources. This report summarizes the work conducted in southern and western Maine under the Maine Peat Resource Evaluation Program. It includes sketch maps, sections and laboratory analyses on which estimates of the resources are based. These data may be utilized to more accurately assesss the energy and agricultural potential of Maine's peatlands. Virtually all peat sold in the United States in 1979 was used for agricultural and horticultural purposes. It was marketed through nurseries, garden centers, and chain stores chiefly in suburban areas of the north-central, northeastern, and middle Atlantic states and Florida. Production during 1980 in the United States was estimated (Searles, 1981) at 790,000 short tons for agricultural use. Value of the 1980 production was about $17,000,000, and the average value per ton was about $21.80. Apparent consumption of peat in the United States during 1980, however, was 1,115,000 short tons, of which imports composed 355,000 short tons.

Cameron, C.C.; Mullen, M.K.; Lepage, C.A.

1983-01-01

331

Short-Term Reducing Conditions Decreases Soil Aggregation  

Technology Transfer Automated Retrieval System (TEKTRAN)

Upland soils in Midwestern US are often ponded during the spring for days or weeks and may undergo reducing state. Short-term reducing conditions change the chemistry of the soil and that may affect soil aggregation. The objective of this paper was to determine how changes in the redox status of the...

332

Quantitative determination of minerals and anthropogenic particles in some Polish peat occurrences using a novel SEM point-counting method.  

PubMed

A method is proposed for determining the mineral composition of peat using scanning electron microscope. In an illustrative example, five groups of particles occurring in amounts of >0.05% are distinguished in peat from Pu?cizna Ma?a bog in the Carpathian foreland, Poland. These are spheroidal aluminosilicate particles (SAP), feldspars, nondescript aluminosilicates (mainly clays), silica (quartz and opaline silica), and Fe(hydro)oxides. Two more site-specific groups (barite and ZnS) are distinguished in highly polluted fens (Bagno Bruch and Bagno Miko?eska) near a zinc smelter in Upper Silesia. At Bagno Bruch, peat contents of predominantly authigenic ZnS microspheroids range up to 1.1%. SAP originating from coal-burning power stations account for maximum concentrations of <21-39% of the inorganic fraction in the studied mires. SAP concentrations vary with depth, and mean spheroid diameters with distance from emission sources. A distinct feature of SAP is their common enrichment in Ti what questions the use of Ti as a proxy for soil dust in fly ash polluted bogs. As amounts of anthropogenic magnetic spherules, less abundant than SAP in all mires, relate to water table level position, they are unsuitable as tracers of air pollution. The proposed method is recommended for application with peats having ash contents?>?~4%. PMID:24442577

Smieja-Król, Beata; Fia?kiewicz-Kozie?, Barbara

2014-04-01

333

Phenological assessment in the Owhyee Uplands: integrating climate drivers and ecological response at local to regional scales  

NASA Astrophysics Data System (ADS)

The seasonal cycle of vegetation change in biomass, structure, and composition is a dominant landscape feature influencing many ecosystem components of the Owyhee Uplands particularly resident and migratory vertebrates and invertebrates. Encompassing portions of Idaho, Nevada, and Oregon, the Owyhee Uplands have remained relatively intact with climate, exotic plant invasions, and anthropogenic agents, such as grazing, acting as the principle causes of ecosystem stress. The sagebrush habitats of the Owyhee Uplands are a stronghold for several federal and state species of special concern, including the Greater sage-grouse (Centrocercus urophasianus). We examined phenological variation in response to climate conditions such as temperature, relative humidity, precipitation, soil moisture, solar irradiance, and snowfall at a range of spatial and temporal scales across a gradient of soil and landforms. We integrated/analyzed measures of greenness derived from ground-based cameras and several satellite sensors (AVHRR, MODIS, and Landsat), early and late season field-collected measures of plant species cover and passerine bird diversity and abundance, daily measurement of soil moisture conditions from in-situ sensors, site-level snow depth conditions from thermochron fitted snow poles, and climate conditions derived from a combination of site-based meteorological stations and interpolated PRISM data. Our objectives include 1) quantifying covariation between greenness-climate-soil-snow conditions and vertebrate and plant species phenology, 2) spatial interscale comparisons of the covariation, and 3) recommendations for on-going data collection and analysis methods to explore phenological response within the context of the natural range of variability and under climate change scenarios.

Torregrosa, A.; Hanser, S.; Tumbusch, M. L.; Bedford, D.

2009-12-01

334

Integrating parsimonious models of hydrological connectivity and soil biogeochemistry to simulate stream DOC dynamics  

NASA Astrophysics Data System (ADS)

improve understanding and prediction of dissolved organic carbon (DOC) sources and fluxes in northern peat-dominated catchments, we present the development and application of a parsimonious tracer-aided rainfall-runoff model coupled with a biogeochemistry subroutine able to concurrently simulate streamflow and DOC dynamics. The modeling approach which included quantitative assessment of associated uncertainties was conditioned by geochemical tracers which discriminate dominant water sources. Integration of DOC was predicated on statistical time series models which identified air temperature and streamflow as the key proxies that capture DOC supply and transport processes in two upland catchments in Scotland, UK. Conceptualizing the nonlinear partitioning of quick near-surface and slower groundwater runoff sources in combination with a DOC mass balance resulted in a coupled, low-parameter mechanistic model. Model tests showed mostly sensitive parameters and reasonable simulation results with seasonally controlled DOC supply and event-based DOC transport. Transport is facilitated even for smaller events by overland flow from saturated histosols connected to the stream network. However, during prolonged dry periods, near-surface runoff "switches off" and stream DOC is dominated by low concentration groundwaters. Furthermore, the model was able to explain subtle differences in DOC dynamics between the two catchments mainly reflecting the distribution of saturated soils and available storage. We conclude that tracers and statistical time series models can successfully guide the development of parsimonious yet structurally consistent water quality models. Parsimonious models provide tools for estimating DOC dynamics and loads with reduced uncertainty and potentially greater transferability.

Birkel, Christian; Soulsby, Chris; Tetzlaff, Doerthe

2014-05-01

335

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

NASA Astrophysics Data System (ADS)

Nitrogen belongs to chemical elements whose biogeochemical cycles are most heavily disturbed by human activities, and large regions worlwide experience elevated depositions of reactive N (NO3-, NH4+). Peatlands contain as much as 15 % of the world's soil N. It it is unclear whether fertilizing by anthopogenic N will lead to higher storage of C in wetlands. Elevated N input may lead to both higher net primary productivity, but will also augment microbial decomposition. Here we discuss two aspects of N cycling in Sphagnum-dominated bogs in the Czech Republic, an area characterized by a steep north-south pollution gradient and high annual N deposition (60 kg ha-1). These two aspects are N inventory in 210Pb-dated peat cores, and post-depositional mobility of N in peat. We compared the N inventory in two Czech bogs, differing in pollution, with cumulative atmospheric N input. We hypothesized that the total amount of N in the peat cores would be smaller than the cumulative N input (leaching of excess N from the bog, denitrification). The two bogs were VJ (industrial north) and CB (rural south). The investigated period was 1885-2002. The total amount of N was 4020 kg ha-1 at VJ and 1530 kg ha-1 at CB. Peat in the north contained 2.6 times more N than in the south. Historical rates of N deposition in the Czech Republic are well known (numerous papers by Kopacek). To estimate cumulative N inputs into the bogs, we also used the monthly N depositions between 1994 and 2002, measured in two nearby catchments. The estimated cumulative atmospheric N input was 1350 kg ha-1 at VJ, and 530 kg ha-1 at CB. In both cases, the amount of N found in peat was 3 times higher than the estimated atmospheric N input. Such high storage of N in peat is surprising. Post-depositional mobility of N may help to explain the discrepancies between atmospheric N inputs and N storage in peat. We found two-fold evidence for post-depositional mobility of N. Maximum N concentrations at VJ were observed in layers dated at 1950, whereas pollution level increased up to 1980, and dropped thereafter. At the end of an 18-month reciprocal peat transplant experiment between VJ and CB, we found that N isotope ratios N converged to the host site. The magnitude of the isotope change was 3 per mil, the affected depth was 10 cm. Our results are consistent with the concept of Lamers et al. (2000) in that both ^15N and the found shift in N peaks downcore confirmed removal of N from surface moss under high N depositions. On the other hand, the excess of stored N relative to the cumulative N input remains unexplained, and merits further study.

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

2013-04-01

336

The Saprotrophic Bacterial Complex in the Raised Peat Bogs of Western Siberia  

Microsoft Academic Search

The population density of bacteria in peat deposits along the landscape profile of the Vasyugan Marsh has been found to be as high as tens of millions of CFU\\/g peat. The abundance and diversity of bacteria increased with depth within the peat deposit, correlating with an increasing level of peat degradation. Variations in these parameters with depth and season were

A. V. Golovchenko; Yu. V. Sannikova; T. G. Dobrovol’skaya; D. G. Zvyagintsev

2005-01-01

337

Geologic evolution of Trail Ridge eolian heavy-mineral sand and underlying peat, northern Florida  

SciTech Connect

Trail Ridge ilmenite-ore sand is eolian in origin. Underlying freshwater-swamp peats are the same age, and sand impurities in peat record the approach of the dune. The original alteration state of detrital heavy minerals is preserved in the peat also. This book discusses the geologic evolution of Trail Ridge eolian heavy-mineral sand and underlying peat.

Force, E.R.; Rich, F.J.

1989-01-01

338

SYNTHESIS OF WESTERN WILLET (Catoptrophorus semipalmatus inornatus) MARBLED GODWIT (Limosa fedoa), AND UPLAND SANDPIPER (Bartramia  

E-print Network

SYNTHESIS OF WESTERN WILLET (Catoptrophorus semipalmatus inornatus) MARBLED GODWIT (Limosa fedoa semipalmatus inornatus) MARBLED GODWIT (Limosa fedoa), AND UPLAND SANDPIPER (Bartramia longicauda) RESEARCH semipalmatus inornatus) MARBLED GODWIT (Limosa fedoa), AND UPLAND SANDPIPER (Bartramia longicauda) RESEARCH

339

Atmospheric Deposition of Trace Elements in Ombrotrophic Peat as a Result of Anthropic Activities  

NASA Astrophysics Data System (ADS)

Ombrotrophic peat can be defined as a soil rich in organic matter, formed from the partial decomposition of vegetable organic material in a humid and anoxic environment, where the accumulation of material is necessarily faster than the decomposition. From the physical-chemical point of view, it is a porous and highly polar material with high adsorption capacity and cation exchange. The high ability of trace elements to undergo complexation by humic substances happens due to the presence of large amounts of oxygenated functional groups in these substances. Since the beginning of industrialization human activities have scattered a large amount of trace elements in the environment. Soil contamination by atmospheric deposition can be expressed as a sum of site contamination by past/present human activities and atmospheric long-range transport of trace elements. Ombrotrophic peat records can provide valuable information about the entries of trace metals into the atmosphere and that are subsequently deposited on the soil. These trace elements are toxic, non-biodegradable and accumulate in the food chain, even in relatively low quantities. Thus studies on the increase of trace elements in the environment due to human activities are necessary, particularly in the southern hemisphere, where these data are scarce. The aims of this study is to evaluate the concentrations of mercury in ombrotrophic peat altomontanas coming from atmospheric deposition. The study is conducted in the Itatiaia National Park, Brazilian conservation unit, situated between the southeastern state of Rio de Janeiro, São Paulo and Minas Gerais. An ombrotrophic peat core is being sampled in altitude (1980m), to measure the trace elements concentrations of this material. As it is conservation area, the trace elements found in the samples is mainly from atmospheric deposition, since in Brazil don't exist significant lithology of trace elements. The samples are characterized by organic matter content which is determined by calcination and pH. For the determination of mercury, an aliquot of 10 mL of sample with 5 mL of the reducing agent 2 % SnCl2, purged with air by atomic absorption spectrophotometry by cold vapor, EAAVF is being used. The determination of other trace elements (Zn, Cd and Pb) is analyzed by flame atomic absorption spectroscopy (FAAS).

Fabio Lourençato, Lucio; Cabral Teixeira, Daniel; Vieira Silva-Filho, Emmanoel

2014-05-01

340

Microbial community response to permafrost thaw after wildfire in an Alaskan upland boreal forest  

NASA Astrophysics Data System (ADS)

Fire is a major factor controlling the long-term dynamics of soil carbon in Alaskan boreal forests. Wildfire not only contributes to a significant global emission of greenhouse gasses but also can indirectly result in the deepening of the active layer and thawing of near-surface permafrost due to reductions in organic layer depth and increases in heat flux through soil. Although boreal ecosystems are fire-adapted, increased fire frequency and rising global temperatures may result in warmer soils and therefore increase the metabolic rates of decomposer microbes and result in accelerated permafrost decomposition and greenhouse gas fluxes. In addition to fire-mediated changes in soil and vegetation structure, changes in the soil microbial community structure are likely to have consequences for rates of soil carbon cycling. In this study we aimed to define the impact of fire on soil microbial communities in an upland black spruce forest and to assess microbial metabolic potential for soil respiration, methanogenesis, and nitrous oxide (N2O) flux. Soil samples from two fire impacted and three control (unburned) locations were collected near Nome Creek, AK, an upland moderately drained black spruce forest. This location was within the Boundary fire that burned between mid-June and the end of August 2004. Soil temperature measurements from before and after the fire showed that soils were warmer after the fire event and the permafrost thawed below 1m. At each sampling location, soil and permafrost samples were collected every 10 cm to a depth of 1 m. Besides biochemical characterization, CO2, CH4, N2O fluxes and potential activities of enzymes involved in extracellular decomposition of complex organic molecules (hemicellulose, chitin and lignin) were measured. The microbial community composition in the samples was determined by sequencing of 16S rRNA genes and microbial metabolic potential was assessed via sequencing of total genomic DNA (metagenomics) in selected active, transition and permafrost layers. Fire impacted locations were characterized with higher pH, soil moisture, and dissolved organic carbon concentrations compared to control locations. CO2 and CH4 fluxes were lower in burned sites compared to control sites, particularly at the depth of permafrost. In contrast, N2O production was higher in burned soils. All of the enzymes had significantly lower activity in fire affected locations than in controls. There were no major differences in the microbial diversity of active layers between fire impacted and control locations. However, microbial diversity was lower in thawed permafrost layers of the burned samples compared to the controls. At all depths the microbial community composition was significantly different between burned and unburned sites. Metagenome sequencing revealed reduced metabolic capacity in genes for sugar and carbohydrate processing in burned active layer soils, whereas some genes for other processes such as stress response were enriched in thawed permafrost layers. In this ongoing project, microbial communities and processes will be further investigated to determine linkages between genomics, enzyme activities, and greenhouse gas fluxes.

Tas, N.; Jorgenson, M. T.; Wang, S.; Berhe, A. A.; Wickland, K. P.; Waldrop, M. P.; Jansson, J. K.

2012-12-01

341

RIPARIAN AND UPLAND BREEDING-BIRD ASSEMBLAGES ALONG HEADWATER STREAMS IN MICHIGAN'S UPPER PENINSULA  

E-print Network

RIPARIAN AND UPLAND BREEDING-BIRD ASSEMBLAGES ALONG HEADWATER STREAMS IN MICHIGAN'S UPPER PENINSULA Drive, Houghton, MI 49931, USA Abstract: Comparative studies of riparian and upland bird communities counts to survey bird assemblages and measure forest habitat character- istics along riparian and upland

Flaspohler, David

342

Analysis of sea-island cotton and upland cotton in response to Verticillium dahliae infection by RNA sequencing  

PubMed Central

Background Cotton Verticillium wilt is a serious soil-borne vascular disease that causes great economic loss each year. However, due to the lack of resistant varieties of upland cotton, the molecular mechanisms of resistance to this disease, especially to the pathogen Verticillium dahliae, remain unclear. Results We used the RNA-seq method to research the molecular mechanisms of cotton defence responses to different races of Verticillium dahliae by comparing infected sea-island cotton and upland cotton. A total of 77,212 unigenes were obtained, and the unigenes were subjected to BLAST searching and annotated using the GO and KO databases. Six sets of digital gene expression data were mapped to the reference transcriptome. The gene expression profiles of cotton infected with Verticillium dahliae were compared to those of uninfected cotton; 44 differentially expressed genes were identified. Regarding genes involved in the phenylalanine metabolism pathway, the hydroxycinnamoyl transferase gene (HCT) was upregulated in upland cotton whereas PAL, 4CL, CAD, CCoAOMT, and COMT were upregulated in sea-island cotton. Almost no differentially expressed genes in this pathway were identified in sea-island cotton and upland cotton when they were infected with V. dahliae V991 and V. dahliae D07038, respectively. Conclusions Our comprehensive gene expression data at the transcription level will help elucidate the molecular mechanisms of the cotton defence response to V. dahliae. By identifying the genes involved in the defence response of each type of cotton to V. dahliae, our data not only provide novel molecular information for researchers, but also help accelerate research on genes involved in defences in cotton. PMID:24314117

2013-01-01

343

Warming-induced reduced peat accrual rates and potential C losses in Northern U.S  

NASA Astrophysics Data System (ADS)

Peatlands located at northern latitudes represent a sink of carbon (C) that is at risk of being lost to the atmosphere if current and expected changes in climate accelerate existing C stock decomposition rates. The extent of such potential loss is still unknown, but recent studies suggest that accrual rate of this critical C stock may be in decline due to more rapid decomposition of plant material reaching the soil. The consequences for our climate system can be significant. If large amounts of C currently ';locked' belowground in peatland ecosystems were to be decomposed and hence lost to the atmosphere, atmospheric concentration of CO2 would increase, causing further warming and hence even more rapid decomposition of peatland C. Our objective in this study is to investigate and compare past and more recent rates of C accrual in peatlands to determine if the rates of C accrual are declining. We collected intact frozen blocks of peat from three sites in Northern Minnesota and sectioned them into horizontal slices, which are being dated by 137Cs and 14C. Atmospheric concentrations of both 137Cs and 14C spiked in the 1960's due to nuclear bomb testing, leaving a ';signature' in organic matter (14C) and sediments (137Cs). The signal has steadily declined since that time. Detection of the signal in current soil samples will allow us to date the sample and consequently to measure the quantity of C accrued in the peat over various measured time intervals.

Fissore, C.; Nater, E. A.; Moskun, A.; Klein, A.; Le, T.

2013-12-01

344

Effects of Tropical Forest Conversion on Hydrologic Response: Process Implications for Potable Water and Sediment Budgets in Karstic Uplands  

NASA Astrophysics Data System (ADS)

Conversion forest to agricultural land has been attended by marked hydrological and ecological responses and has arguably made a considerable contribution to global change. These changes have been less well studied in the tropics than in temperate climates, yet the impact of such changes is more immediate for rural landholders in the tropic than for western, industrialized societies, who rely on infrastructure to buffer the effects of global change. The most immediate concern of upland farmers in Leyte, Philippines was the decreasing availability of water, both for household and agricultural use. They attributed the changes in hydrology to deforestation, but were unclear about the hydrologic processes involved. The primary goal of development organizations conducting projects in the region was soil conservation, through implementation of erosion control practices. This study was conducted to identify the mechanisms governing hydrologic change and soil loss in a succession of land uses. Forest removal was found to have less dramatic impacts on surface runoff than did subsequent changes in the soil associated with agricultural use. Soil erosion was more strongly associated with soil disturbance than with extent of surface runoff. The interplay between the shift in hydrologic processes and disturbance frequency for the agricultural land uses resulted in the proposed conservation practice exacerbating the erosion rates within the catchments. Although on site erosion for the pasture catchment was minimal, this treatment was found to have the lowest infiltration capacity and likely contributed greatly to the loss of perennial springs in the uplands and erosion of lowland rice paddies. These results suggest that land uses and agricultural practices that maintain soil infiltration capacity will have the greatest success in maintaining local potable water sources and reducing soil erosion.

Chandler, D. G.

2003-12-01

345

Solute movement through unsaturated fen peat: Lab and greenhouse experiments for transport study of contaminants from Athabasca oil sands tailing pond water  

NASA Astrophysics Data System (ADS)

In the Athabasca oil sands region, wetlands specially peatland dominate the landscape. Processing oil sands produces large volumes of wet material called oil sands tailing water. Discharge of organic liquid contaminants such as Naphthenic Acids (NA) and Sodium (Na) from tailing waters have a toxic effect on plants in this region. One of the greatest barriers to peatland creation will be the elevated amount of toxins (naphthenic acid, metals and salinity) present in the post-mined landscapes. Variability in solute transport properties in the unsaturated zone is of growing concern due to environmental hazards and there are no many scientific challenges in the field of organic liquid contaminants transport through the unsaturated peat soils. The attenuation, degradation and transport of NA and Na in peat are essentially unknown. The ionizable nature of NA and Na along with the complex structure of peat soils poses challenges to characterizing the transport properties of NA and Na in the filed and laboratory. In this experimental research project, we examine the plant responses in 64 greenhouse tubs filled with peat and process-water; and study the transport and attenuation processes of NA and Na through peat in a series of laboratory column experiments. We developed an analytical method for evaluating the transport and adsorption characteristics of NA and Na to derive a clear understanding of the transport, sorption mechanisms and desorption behaviour of NA and Na with temporal evolution of the solute concentration distribution from groundwater to fen plants. The goal of this research project is to investigate how oil sands process-affected waters will affect peatland vegetation, specifically fen vegetation. In particular, we would like to know how contaminants present in oil sand process affected water will be transported through peat and how typical fen vegetation will react to a realistic contamination scenario in a controlled macrocosm environment? Research that responds to the above-mentioned questions will be taking a clear step towards addressing the future outcomes of oil sand affected landscapes.

Price, J. S.; Rezanezhad, F.; Graf, M.; Rochefort, L.

2009-12-01

346

Estimating Effects of Atmospheric Deposition and Peat Decomposition Processes on Mercury and Sulfur Accumulation and Retention in Northern Peatlands, Minnesota  

NASA Astrophysics Data System (ADS)

Northern peatland ecosystems play an important role in mercury (Hg) and sulfur (S) co-cycling. Peatlands are sinks for total Hg and sources for methyl Hg through the activity of sulfate-reducing bacteria. These ecosystems are vulnerable to environmental change, and projected changes in climate for the north-central U.S. have the potential to affect Hg and S stores and cycling in the subsurface, which may stimulate the release of bioaccumulative methyl Hg to receiving water bodies. SPRUCE (Spruce and Peatland Responses under Climate and Environmental change experiment) is an interdisciplinary study of the effects of temperature and enriched carbon dioxide on the responses of northern peatland ecosystems at the Marcell Experimental Forest, Minnesota. In the first year of SPRUCE, we are investigating Hg and S accumulation rates in 12-m diameter experimental plots on a black spruce bog before peatland heating experiments start in 2014. Understanding Hg and S accumulation rates and their retention mechanisms in the subsurface are needed in order to reconstruct historical trends in Hg and S deposition, and predict peatland responses to climate change. In this study, we will attempt to separate the effects of atmospheric deposition vs peat humification on Hg and S retention. As such, peat cores were sampled from sixteen experimental SPRUCE plots in August 2012. These 'Time 0' peat subsamples have been analyzed for total Hg, methyl Hg and total S, and bulk density as a function of depth (<2 m). In addition, peat subsamples have been analyzed for 14C and 13C to determine the age of peat and derive peat, Hg and S accumulation rates. Our preliminary results indicate that both total and methyl Hg, and total S concentrations reached the peak value in the 20-40 cm peat section, which is the transition zone between transiently oxidized acrotelm and permanently saturated anaerobic catotelm. Total and methyl Hg concentrations were several times lower in deeper profiles (>50 cm), and showed lower variability. Changes in Hg and S over depth seem to be associated with the variation in humification of soil organic matter. These findings are critical to better conceptualization as well as parameterization of models that project how climate change will affect the accumulation, cycling, and export of toxic methylmercury from peatlands.

Furman, O.; Nater, E.; Toner, B. M.; Sebestyen, S. D.; Tfaily, M. M.; Chanton, J.; Kolka, R. K.

2013-12-01

347

Stable carbon and oxygen isotopes as an indicator for soil degradation  

NASA Astrophysics Data System (ADS)

Analyses of soil organic carbon content (SOC) and stable carbon and oxygen isotope signatures (^13C) of soils were assessed for their suitability to detect early stage soil erosion. Results were validated with Cs-137 measurements. We investigated the soils in the alpine Urseren Valley (Southern Central Switzerland) which are highly impacted by soil erosion. Hill slope transects from uplands (cambisols) to adjacent wetlands (histosols and histic to mollic gleysols) differing in their intensity of visual soil erosion and reference wetlands without erosion influence were sampled. Carbon isotopic signature and SOC content of soil depth profiles were determined. A close correlation of ^13C and carbon content (r > 0.80) is found for upland soils not affected by soil erosion, indicating that depth profiles of ^13C of these upland soils mainly reflect decomposition of SOC. Long term disturbance of an upland soil is indicated by decreasing correlation of ^13C and SOC (r ? 0.80) which goes parallel to increasing (visual) damage at the site. Early stage soil erosion in hill slope transects from uplands to adjacent wetlands is documented as an intermediate ^13C value (27.5 ) for affected wetland soil horizons (0 - 12 cm) between upland (aerobic metabolism, relatively heavier ^13C of 26.6 ) and wetland isotopic signatures (anaerobic metabolism, relatively lighter ^13C of 28.6 ). Cs-137 measurements confirmed stable isotope analysis. Stable oxygen isotope signature (^18O) of soil is the result of a mixture of the components within the soil with varying ^18O signatures. Thus, ^18O of soils should provide information about the soil's substrate, especially about the relative contribution of organic matter versus minerals. As there is no standard method available for measuring soil ^18O, the method for measurement of single components using High Temperature Conversion Elemental Analyzer (TC/EA) was adapted. We measured ^18O in standard materials (IAEA 601, IAEA 602, Merck Cellulose) and soils (organic and mineral soils) in order to determine a suitable pyrolysis temperature for soil analysis. We considered a pyrolysis temperature suitable when the yield of signal intensity (mass 28 per 100 g) is at a maximum and acquired raw ^18O signature is constant for used standard materials and when the quartz signal from the soil is still negligible. After testing several substances within the temperature range of 1075 to 1375 Ë? C we decided to use a pyrolysis temperature of 1325 Ë? C for further measurements. For the Urseren Valley we have found a sequence of increasing ^18O signatures from phyllosilicates to upland soils, wetland soils and vegetation. Our measurements show that ^18O of upland soil samples differ significantly from wetland soil samples. The latter can be related to changing mixing ratio of mineral and organic constituents of the soil. For wetlands affected by soil erosion, we have found intermediate ^18O signatures which lie between typical signatures for upland and wetland sites and give evidence for input of upland soil material through erosion. To conclude, carbon isotopic signature and SOC content are found to be a sensitive indicator of short and long term soil erosion processes. Regarding stable oxygen isotopes, we consider ^18O to have potential as a suitable tracer for soil erosion in transects from upland to wetland soils. However, soil erosion detection with ^18O needs to be verified at other sites with differing geology, climate, altitude and vegetation to acquire an even broader understanding of ^18O of soils.

Alewell, C.; Schaub, M.; Seth, B.

2009-04-01

348

Foam concrete of increased strength with the thermomodified peat additives  

NASA Astrophysics Data System (ADS)

The paper presents the results of research of foam concrete with thermomodified peat additives. The aim of the research was to study the effect of modifying additives on cement stone and foam concrete properties. Peat additives are prepared by heat treatment of peat at 600 °C. Two approaches of obtaining additives are examined: in condition of open air access (TMT-600) and in condition of limited air access (TMT-600-k). Compressive strength of a cement stone with modifiers found to be increased by 28.9 – 65.2%. Introducing peat modifiers into foam concrete mix leads to increase of compressive strength by 44-57% at 28- day age and heat conductivity of foam concrete decreases by 0.089 W/(m·°C).

Kudyakov, A. I.; Kopanitsa, N. O.; Sarkisov, Ju S.; Kasatkina, A. V.; Prischepa, I. A.

2015-01-01

349

Water and nutrient input:output budgets: effects of plant cover at seven sites in upland snow tussock grasslands of Eastern and Central Otago, New Zealand  

Microsoft Academic Search

Input:output budgets of water and macronutrients over two years are reported for three cover types (unmodified snow tussock grassland; induced short (c. 10 cm) blue tussock grassland; bare soil) in replicated non-weighing lysimeters from seven upland sites, four on the Lammerlaw Range (487 m–976 m), Waipori Ecological District, Eastern Otago and three on the Rock and Pillar Range (1000 m

D. K. Holdsworth; A. F. Mark

1990-01-01

350

Influence of water table changes on peat features and humification processes  

NASA Astrophysics Data System (ADS)

Peatland ecosystems play an important role in the carbon cycle. In their natural state, they have been shown to be net sinks for atmospheric carbon dioxide (CO2) and net sources of greenhouse gases on a long term basis. Peatlands could provide a significant positive feedback for climate change. Unfortunately, drainage of peatlands for forestry, agriculture and/or peat extraction for energy is a common practice in several countries (e.g., the Fenno-Scandinavian region, Canada and Russia). When they are drained, peatland areas become a threat to the environment as the thickness of the aerobic layer increases. This leads to an increase in the rate of organic matter (OM) decomposition and, as a result, peatlands might change from a net carbon sink to a large carbon source, thus resulting in an increase of CO2 and methane (CH4) emissions from these organic soils. In order to better understand hydrological, physical and chemical changes occurring as result of water table level changes, we studied the OM evolution of bulk peat and its humified fraction in undisturbed condition. A 81 cm peat core was collected from Etang de la Gruère, a Swiss ombrotrophic bog in the Jura Mountains, and humic acids (HA) isolated. Both bulk peat and HA samples were characterized using several molecular spectroscopic methods (Ft-IR, UV-Vis, DSC, Fluorescence) and elemental analysis (CHNS-O). In general, Ft-IR, UV-Vis and fluorescence results suggest significant variations of the molecular composition and chemical structures of the peat samples along the profile. In detail, the superficial zone (from the living layer to approximately 24 cm) is characterized by oxidative processes and decomposition phenomena of plant tissues and residues continuously occurring in the top horizons of the peat, leading to the release of variable amounts of organic acids and small molecular mass compounds. This section is poorly decomposed. The HA fraction accounts for 6.6 to 15.4% of the bulk peat, thus meaning that only ca. 7.8-17.3% (13.9%, average value) of total C present in peat is stored in the recalcitrant and stable HA fraction, and thus most of the C stock can be easily mineralized. On the opposite, the bottom zone (under 39 cm depth), in which molecules with high molar mass and high degree of condensation are observed, seems more homogeneous and reflects a peat zone apparently characterized by uniform and permanent anoxic conditions. Here, an obligate anaerobic microbial community can carry out only a partial and slow decomposition of the OM. In this section of the profile, the HA fraction accounts for ca. 20.0-32.7% of the bulk peat, representing ca. 25.1-37.1% (28.6%, average value) of total C present in peat is stored in the HA fraction. But the variability in the depth of the water table level, providing temporary oxygen diffusion even at greater depth, originated also a "transitional" zone, from about 24-39 cm. Here, changes between aerobic and anaerobic conditions activated microbially induced humification and transformation processes of polysaccharidic and lignin-derived residues, as well as very complex interactions between organic and inorganic compounds. This section, in fact, was characterized by the highest ash content (4.9%, average value) and, if compared with the deeper layer and part of the upper one, by the occurrence of less humified molecules. In this part of the profile, the HA fraction represents ca. 24.3% (average value) of total C present in bulk peat. In conclusion, and always considering that this study is just a photo of a particular moment, our data suggested that, although a relevant portion of C is stored into the HA fraction, the fluctuations of the water table could favour the temporal exposition of these macromolecules to the microbial activity, thus transforming a stable C pool into a labile one.

Zaccone, Claudio; Miano, Teodoro M.

2010-05-01

351

Environmental effects of dredging: Upland animal bioassays of dredged materials. Technical note  

SciTech Connect

The Clean Water Act in the United States requires that the environmental evaluation of dredged material prior to discharge or impacting the waters of the United States include the effects of disposal on concentrations of contaminants through biological processes. This results in a need for Corps of Engineers districts to be able to predict the contamination of animals that may be associated with potential disposal alternatives: open-water disposal, upland disposal, and wetland creation. The following is a summary of the results of bioassay procedures using the earthworm Eisenia foetida to evaluate the potential contaminant mobility into soil-dwelling animals. These tests were derived from proposed Organization for European Common Development (OECD) and European Economics Commission (EEC) test procedures (evaluating the effects of new chemicals) and modified to consider accumulation and sublethal effects rather than toxicity.

Simmers, J.W.; Rhett, R.G.; Lee, C.R.

1986-01-01

352

The Role of Social Constructions and Biophysical Attributes of the Environment in Decision-Making in the Context of Biofuels and Rubber Production Partnership Regimes in Upland Philippines  

NASA Astrophysics Data System (ADS)

Burgeoning attention in biofuels and natural rubber has spurred interest among governments and private companies in integrating marginalized communities into global commodity markets. Upland farmers from diverse cultural backgrounds and biophysical settings today are deciding whether to agree with partnership proposals from governments and private firms to grow biofuels and natural rubber. In this paper, I examine whether upland farmers' socio-environmental constructions (evaluative beliefs, place satisfaction, and ecological worldviews) and the actual biophysical attributes (land cover and soil types) of upland environments, respectively, function as significant predictors of the intent and decisions of indigenous and non-indigenous farmers to cooperate with government and private actors to establish certain biofuel crops and natural rubber production systems in Palawan, Philippines. Drawing from ethnography and statistical analysis of household surveys, I propose that social constructions and the biophysical attributes of the environment are closely related with each other and in turn both influence individual decision-making behavior in resource-based production partnership regimes. This has significant implications on the resilience of socio-ecological systems, particularly agro-ecosystems, as certain upland farmers prefer to engage in intensive, monocrop production of biofuels and natural rubber on relatively more biodiverse areas, such as secondary forests and traditional shifting cultivation lands. The study aims to advance new institutional theories of resource management, particularly Ostrom's Institutional Analysis and Development and Socio-Ecological Systems frameworks, and scholarship on environmental decision-making in the context of collective action.

Montefrio, M. F.

2012-12-01

353

Geomorphic Analysis of Soils  

NSDL National Science Digital Library

Students are taken to a former plantation along a tidal river near Charleston, SC. The students are then shown how to sample and describe soils using an push-auger sampler, similar to those used in industry. After the demonstration, the students are taken to various locations on the plantation, including upland areas, wetlands, former agricultural areas, lowlands, and tidal marshes, to sample and make field descriptions of the various soils encountered. Students describe depths to horizons, soil color using Munsell Color Charts, soil texture, and any other pertinent properties. Students then prepare a formal technical write-up on the soils, their distribution, and how their sampling results compare to published soil data for the area. Designed for a geomorphology course Uses online and/or real-time data

Briget Doyle

354

Evaluation of the VIIRS Land Algorithms at Land PEATE  

NASA Technical Reports Server (NTRS)

The Land Product Evaluation and Algorithm Testing Element (Land PEATE), a component of the Science Data Segment of the National Polar-orbiting Operational Environmental Satellite System (NPOESS) Preparatory Project (NPP), is being developed at the NASA Goddard Space Flight Center (GSFC). The primary task of the Land PEATE is to assess the quality of the Visible Infrared Imaging Radiometer Suite (VIIRS) Land data products made by the Interface Data Processing System (IDPS) using the Operational (OPS) Code during the NPP era and to recommend improvements to the algorithms in the IDPS OPS code. The Land PEATE uses a version of the MODIS Adaptive Processing System (MODAPS), NPPDAPS, that has been modified to produce products from the IDPS OPS code and software provided by the VIIRS Science Team, and uses the MODIS Land Data Operational Product Evaluation (LDOPE) team for evaluation of the data records generated by the NPPDAPS. Land PEATE evaluates the algorithms by comparing data products generated using different versions of the algorithm and also by comparing to heritage products generated from different instrument such as MODIS using various quality assessment tools developed at LDOPE. This paper describes the Land PEATE system and some of the approaches used by the Land PEATE for evaluating the VIIRS Land algorithms during the pre-launch period of the NPP mission and the proposed plan for long term monitoring of the quality of the VIIRS Land products post-launch.

Wolfe, Robert E.; Devadiga, Sadashiva; Ye, Gang; Masuoka, Edward J.; Schweiss, Robert J.

2010-01-01

355

Effect of peat on physicomechanical properties of cemented brick.  

PubMed

The popularity of low cost, lightweight, and environmentally affable masonry unit in building industry carries the need to investigate more flexible and adaptable brick component as well as to retain the requirements confirmed in building standards. In this study, potential use of local materials used as lightweight building materials in solving the economic problems of housing has been investigated. Experimental studies on peat added bricks have been carried out. It demonstrates the physicomechanical properties of bricks and investigates the influence of peat, sand, and cement solid bricks to the role of various types of constructional applications. The achieved compressive strength, spitting strength, flexural strength, unit weight, and ultrasonic pulse velocity are significantly reduced and the water absorption is increased with percentage wise replacement of peat as aggregate in the samples. The maximum 20% of (% mass) peat content meets the requirements of relevant well-known international standards. The experimental values illustrate that, the 44% volumetric replacement with peat did not exhibit any sudden brittle fracture even beyond the ultimate loads and a comparatively smooth surface is found. The application of peat as efficient brick substance shows a potential to be used for wall and a viable solution in the economic buildings design. PMID:24982941

Islam, Syed Mofachirul; Hashim, Roslan; Islam, A B M Saiful; Kurnia, Ryan

2014-01-01

356

Effect of Peat on Physicomechanical Properties of Cemented Brick  

PubMed Central

The popularity of low cost, lightweight, and environmentally affable masonry unit in building industry carries the need to investigate more flexible and adaptable brick component as well as to retain the requirements confirmed in building standards. In this study, potential use of local materials used as lightweight building materials in solving the economic problems of housing has been investigated. Experimental studies on peat added bricks have been carried out. It demonstrates the physicomechanical properties of bricks and investigates the influence of peat, sand, and cement solid bricks to the role of various types of constructional applications. The achieved compressive strength, spitting strength, flexural strength, unit weight, and ultrasonic pulse velocity are significantly reduced and the water absorption is increased with percentage wise replacement of peat as aggregate in the samples. The maximum 20% of (% mass) peat content meets the requirements of relevant well-known international standards. The experimental values illustrate that, the 44% volumetric replacement with peat did not exhibit any sudden brittle fracture even beyond the ultimate loads and a comparatively smooth surface is found. The application of peat as efficient brick substance shows a potential to be used for wall and a viable solution in the economic buildings design. PMID:24982941

Hashim, Roslan; Kurnia, Ryan

2014-01-01

357

Impact of Water Level on Carbon Sequestration at a Sub-tropical Peat Marsh  

NASA Astrophysics Data System (ADS)

The impact of water level on sub-tropical peat marsh atmospheric/landscape carbon exchange was explored through eddy-covariance measurement of carbon dioxide and methane fluxes over a site at Blue Cypress Conservation Area in Florida. This site is vegetated with tall, dense sawgrass (Cladium jamaicense) and a thick accumulation of peat (over 3 m) suggesting a historically high primary productivity and carbon sequestration. Water managers are particularly interested in understanding how water-level controls can be directed to maintain topography through avoidance of excessive drought-induced oxidative losses of peat soil, as well as to minimize releases of greenhouse gases to the atmosphere. Comparison of net ecosystem productivity (NEP) during a wet year of continuous inundation and a drier year with a 9-month hydroperiod (NEP of 710 and 180 g C/m2/yr, respectively) suggests the positive impact of inundation on sequestration of carbon dioxide. These results are counter to previous research in short stature (1 m or less) sawgrass marshes in the Florida Everglades which indicate suppression of productivity during inundation. This seeming contradiction is probably best explained by the tall stature (over 2 m) of sawgrass at the study site in which inundation still does not cover a substantial fraction of the green leaves and the lower canopy is largely composed of brown and decaying leaves. Gross ecosystem productivity (GEP) was suppressed during the dry year (GEP = 1380 and 1030 g C/m2/yr for wet and dry years, respectively), probably as a consequence of canopy moisture stress. Respiration (R) was enhanced the year when water levels were farthest below land surface (R = 670 and 850 g C/m2/yr for wet and dry years, respectively) as a result of soil oxidation. GEP remained suppressed during the dry year even after re-flooding, probably because of relatively low photosynthetic leaf area that was the legacy of reduced canopy growth rates during the drought. Over a seven-month measurement period spanning a dry-to-inundated transition in the marsh, methane flux was negligible during non-inundated periods, but was substantial (averaging 80 g C/m2/yr) during wet periods. The results of this study suggest that water level is a critical control on atmospheric carbon exchanges at this peat marsh with implications for water management and strategic planning under potentially drier conditions that might occur in response to climate change.

Sumner, D.; Hinkle, C.; Li, J.

2012-12-01

358

Impact of Water Level on Carbon Sequestration at a Sub-tropical Peat Marsh  

NASA Astrophysics Data System (ADS)

The impact of water level on sub-tropical peat marsh atmospheric/landscape carbon exchange was explored through eddy-covariance measurement of carbon dioxide and methane fluxes over a site at Blue Cypress Conservation Area in Florida. This site is vegetated with tall, dense sawgrass (Cladium jamaicense) and a thick accumulation of peat (over 3 m) suggesting a historically high primary productivity and carbon sequestration. Water managers are particularly interested in understanding how water-level controls can be directed to maintain topography through avoidance of excessive drought-induced oxidative losses of peat soil, as well as to minimize releases of greenhouse gases to the atmosphere. Comparison of net ecosystem productivity (NEP) during a wet year of continuous inundation and a drier year with a 9-month hydroperiod (NEP of 710 and 180 g C/m2/yr, respectively) suggests the positive impact of inundation on sequestration of carbon dioxide. These results are counter to previous research in short stature (1 m or less) sawgrass marshes in the Florida Everglades which indicate suppression of productivity during inundation. This seeming contradiction is probably best explained by the tall stature (over 2 m) of sawgrass at the study site in which inundation still does not cover a substantial fraction of the green leaves and the lower canopy is largely composed of brown and decaying leaves. Gross ecosystem productivity (GEP) was suppressed during the dry year (GEP = 1380 and 1030 g C/m2/yr for wet and dry years, respectively), probably as a consequence of canopy moisture stress. Respiration (R) was enhanced the year when water levels were farthest below land surface (R = 670 and 850 g C/m2/yr for wet and dry years, respectively) as a result of soil oxidation. GEP remained suppressed during the dry year even after re-flooding, probably because of relatively low photosynthetic leaf area that was the legacy of reduced canopy growth rates during the drought. Over a seven-month measurement period spanning a dry-to-inundated transition in the marsh, methane flux was negligible during non-inundated periods, but was substantial (averaging 80 g C/m2/yr) during wet periods. The results of this study suggest that water level is a critical control on atmospheric carbon exchanges at this peat marsh with implications for water management and strategic planning under potentially drier conditions that might occur in response to climate change.

Sumner, D.; Hinkle, C.; Graham, S.; Li, J.

2013-12-01

359

Effects of fire on the thermal stability of permafrost in lowland and upland black spruce forests of interior Alaska in a changing climate  

USGS Publications Warehouse

Fire is an important factor controlling the composition and thickness of the organic layer in the black spruce forest ecosystems of interior Alaska. Fire that burns the organic layer can trigger dramatic changes in the underlying permafrost, leading to accelerated ground thawing within a relatively short time. In this study, we addressed the following questions. (1) Which factors determine post-fire ground temperature dynamics in lowland and upland black spruce forests? (2) What levels of burn severity will cause irreversible permafrost degradation in these ecosystems? We evaluated these questions in a transient modeling–sensitivity analysis framework to assess the sensitivity of permafrost to climate, burn severity, soil organic layer thickness, and soil moisture content in lowland (with thick organic layers, ~80 cm) and upland (with thin organic layers, ~30 cm) black spruce ecosystems. The results indicate that climate warming accompanied by fire disturbance could significantly accelerate permafrost degradation. In upland black spruce forest, permafrost could completely degrade in an 18 m soil column within 120 years of a severe fire in an unchanging climate. In contrast, in a lowland black spruce forest, permafrost is more resilient to disturbance and can persist under a combination of moderate burn severity and climate warming.

Jafarov, Elchin E.; Romanovsky, Vladimir E.; Genet, Helene; McGuire, Anthony D.; Marchenko, Sergey S.

2013-01-01

360

A comparison of F2 distributions of certain economic characters in crosses of six "foreign" upland cotton stocks with an American upland tester stock  

E-print Network

supplanted to a notable extent by G. hirsutum types. For the purpose of discussion in this paper "Upland" will denote those varieties or types of G. hirsutum (race latifolium) which were introduced into the United States from the center of origin and were... stocks included representatives of the African Upland, Indian Upland-Cambodia and Cambodia types of G. hirsutum race latifolium and one representative of the race punetaturn. Detailed information on the history of the six stocks is not available...

Niles, George Alva

2013-10-04

361

A multi-scale modelling procedure to quantify hydrological impacts of upland land management  

NASA Astrophysics Data System (ADS)

Recent UK floods have focused attention on the effects of agricultural intensification on flood risk. However, quantification of these effects raises important methodological issues. Catchment-scale data have proved inadequate to support analysis of impacts of land management change, due to climate variability, uncertainty in input and output data, spatial heterogeneity in land use and lack of data to quantify historical changes in management practices. Manipulation experiments to quantify the impacts of land management change have necessarily been limited and small scale, and in the UK mainly focused on the lowlands and arable agriculture. There is a need to develop methods to extrapolate from small scale observations to predict catchment-scale response, and to quantify impacts for upland areas. With assistance from a cooperative of Welsh farmers, a multi-scale experimental programme has been established at Pontbren, in mid-Wales, an area of intensive sheep production. The data have been used to support development of a multi-scale modelling methodology to assess impacts of agricultural intensification and the potential for mitigation of flood risk through land use management. Data are available from replicated experimental plots under different land management treatments, from instrumented field and hillslope sites, including tree shelter belts, and from first and second order catchments. Measurements include climate variables, soil water states and hydraulic properties at multiple depths and locations, tree interception, overland flow and drainflow, groundwater levels, and streamflow from multiple locations. Fine resolution physics-based models have been developed to represent soil and runoff processes, conditioned using experimental data. The detailed models are used to calibrate simpler 'meta- models' to represent individual hydrological elements, which are then combined in a semi-distributed catchment-scale model. The methodology is illustrated using field and catchment-scale simulations to demonstrate the the response of improved and unimproved grassland, and the potential effects of land management interventions, including farm ponds, tree shelter belts and buffer strips. It is concluded that the methodology developed has the potential to represent and quantify catchment-scale effects of upland management; continuing research is extending the work to a wider range of upland environments and land use types, with the aim of providing generic simulation tools that can be used to provide strategic policy guidance.

Wheater, H. S.; Jackson, B.; Bulygina, N.; Ballard, C.; McIntyre, N.; Marshall, M.; Frogbrook, Z.; Solloway, I.; Reynolds, B.

2008-12-01

362

Chloroplast Genome Variation in Upland and Lowland Switchgrass  

PubMed Central

Switchgrass (Panicum virgatum L.) exists at multiple ploidies and two phenotypically distinct ecotypes. To facilitate interploidal comparisons and to understand the extent of sequence variation within existing breeding pools, two complete switchgrass chloroplast genomes were sequenced from individuals representative of the upland and lowland ecotypes. The results demonstrated a very high degree of conservation in gene content and order with other sequenced plastid genomes. The lowland ecotype reference sequence (Kanlow Lin1) was 139,677 base pairs while the upland sequence (Summer Lin2) was 139,619 base pairs. Alignments between the lowland reference sequence and short-read sequence data from existing sequence datasets identified as either upland or lowland confirmed known polymorphisms and indicated the presence of other differences. Insertions and deletions principally occurred near stretches of homopolymer simple sequence repeats in intergenic regions while most Single Nucleotide Polymorphisms (SNPs) occurred in intergenic regions and introns within the single copy portions of the genome. The polymorphism rate between upland and lowland switchgrass ecotypes was found to be similar to rates reported between chloroplast genomes of indica and japonica subspecies of rice which were believed to have diverged 0.2–0.4 million years ago. PMID:21887356

Young, Hugh A.; Lanzatella, Christina L.; Sarath, Gautam; Tobias, Christian M.

2011-01-01

363

Forest regeneration of upland areas following logging in interior Alaska  

SciTech Connect

A reconnaissance study of post harvest natural regeneration of upland areas near the Parks Highway made to determine stocking densities of desirable species. Data are tabulated showing frequency and density of tree and non-tree species. While revegetation has occurred, the regeneration of commercial tree species is variable (mainly white spruce, birch, and aspen (Populus tremuloides)). Implications for ecology and management are discussed.

Fox, J.D.

1980-01-01

364

Bird populations in upland spruce plantations in northern Britain  

Microsoft Academic Search

The aim of this study was to measure bird numbers and species richness in upland spruce forests in relation to forest habitat variables, as a basis for a computer model to predict how bird populations were likely to change under different forest management regimes.In each of the two study areas, at Cowal, Argyll and Kielder, Northumberland, 88 study plots were

I. J. Patterson; J. G. Ollason; P. Doyle

1995-01-01

365

Organic carbon export from upland and forested wetland watersheds  

Microsoft Academic Search

Export of organic carbon per unit runoff from five small, eastern North Carolina watersheds with considerable swamp drainage was severalfold higher than the export rates from upland watersheds reported in the literature. This reflects the higher concentrations of organic carbon, especially dissolved forms, in swamp waters and is probably attributable to increased contact time between water and organic debris as

PATRICK J. MULHOLLAND; EDWARD J. KUENZLER

1979-01-01

366

DEVELOPING SEED SOURCES OF FLORIDA NATIVE UPLAND GRASS SPECIES 1  

Microsoft Academic Search

There is a growing movement in Florida to revegetate upland sites with Florida native species. Lack of commercial seed sources hinders this work. Several obstacles must be overcome to develop reliable plant materials. Florida natives often have poor seed production or require specific management techniques such as burning, to produce viable seed. Lack of seedling vigor often causes natives to

S. L. Pfaff; C. Maura

367

SUSCEPTIBILITY OF UPLAND COTTON CULTIVARS TO INFESTATION BY SILVERLEAF WHITEFLY  

Technology Transfer Automated Retrieval System (TEKTRAN)

Sixteen upland cotton, Gossypium hirsutum L., cultivars and experimental breeding-lines were evaluated in the field for susceptibility to silverleaf whitefly, Bemisia argentifolii Bellows and Perring, sown at the UC Desert Research & Extension Center, Imperial Valley, CA, into plots of a randomized ...

368

OPEN GROUND IN UPLAND FORESTS: A REVIEW OF ITS  

E-print Network

OPEN GROUND IN UPLAND FORESTS: A REVIEW OF ITS POTENTIAL AS WILDLIFE HABITAT AND APPROPRIATE MANAGEMENT METHODS RUSSELL ANDERSON FOREST RESEARCH November 2003 #12;SUMMARY This review deals. The requirements of various species and groups of plants and animals known to use forest open ground are reviewed

369

Upland fiber changes due to ginning and lint cleaning  

Technology Transfer Automated Retrieval System (TEKTRAN)

A study was done to determine how upland cotton fiber length distribution was affected during ginning and how possible length changes might affect subsequent textile processing. The full range of ginning treatments currently commercially available in the U. S. cotton industry were utilized. These ...

370

Partitioning peat respiration with stable carbon isotopes  

NASA Astrophysics Data System (ADS)

Equimolar production of CO2 and CH4 is assumed with methanogenesis. However, in both field and incubation studies of peat respiration, CO2 is continually reported to be in higher concentrations than CH4. It was assumed that this is due to loss of methane with ebullition and additional CO2 production by HMW organic matter fermentation. To determine the proportions of CO2 formed from both organic matter fermentation and methanogenesis and to determine the percent loss of CH4 from ebullition, isotope mass balance equations were developed. The 13C-CO2 measured in pore water represents a mixture between the 13C-CO2 from organic matter decomposition and methanogenesis. By collecting and analyzing pore water samples for ?13C and concentrations of both CO2 and CH4, the proportion of CO2 formed from organic matter fermentation and methanogenesis was calculated. It was found that, at 0, 154, and 261 cm depths, the percent CO2 from methanogenesis was 56%, 88%, and 91%, and the percent CH4 loss due to ebullition was 69%, 79%, and 85%, respectively. These findings indicate that with increasing depth both the percent CO2 formed from methanogenesis and the percent CH4 lost increased. Incubation experiments consisting of peat from five depth intervals (30-40, 70-80, 130-140, 170-180, and 270-280cm) were used to determine the accuracy of the isotope mass balance equations based on in situ concentrations and isotopic values. Measurements were made biweekly for concentrations and ?13C of CO2 and CH4. The percents of CO2 formed from methanogenesis based on the isotope mass balance equations were found to be to be 53%, 44%, 12%, 51%, and 54% corresponding to the respective depth ranges. The ratios of CH4/CO2 measured were 51%, 39%, 4%, 41%, and 54%, respectively. The average standard deviation between these sample sets was found to be ± 3.5%. This indicates that the isotope mass balance equations are an appropriate model for determining in situ CO2 partitioning in these systems.

Chanton, J.; Corbett, J.; Burdige, D. J.; Glaser, P. H.; Cooper, W. T.; Tfaily, M. M.

2010-12-01

371

Classification of the field drainage and wetness by using aerial photographs in irrigated paddy rice and upland crop rotation field  

NASA Astrophysics Data System (ADS)

Information about field drainage/wetness is useful for farmers to plan field management in irrigated paddy rice and upland crop rotation field. Wet injury is a loss to farmers in upland crop farming, experience is the most common way of approaching this risk. In this study, we propose to provide efficient and objective classify and mapping method of such field drainage information using aerial photography. Study area (500 ha) is located in Ibaraki Prefecture,