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1

THE EROSION OF PEAT IN THE UPLANDS OF NORTHERN IRELAND  

Microsoft Academic Search

Whereas in Britain the erosion of peat in upland areas has been mapped and discussed widely, in Ireland there has been only brief mention of peat erosion and few attempts to map its distribution. In this paper the erosion of the peat in the uplands of Northern Ireland is mapped and classified; water erosion is of two types, anastomosing channels

R. W. Tomlinson

1981-01-01

2

Guidance on peat soils 1 | Peat | Helen Cariss  

E-print Network

Guidance on peat soils 1 | Peat | Helen Cariss Forestry and deep peat Purpose This policy guidance on forestry and deep peat acts as the country level guidance for FCW. It applies to regulatory functions: conserving and enhancing biodiversity climate change mitigation maintaining the peat and soil resource

3

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

4

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

5

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

6

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

Microsoft Academic Search

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)

Simon Dixon; James Rowson; Fred Worrall

2010-01-01

7

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

8

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

NASA Astrophysics Data System (ADS)

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

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

2014-05-01

9

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

10

Adoption of soil conservation: the case of the Philippine uplands  

Microsoft Academic Search

Soil degradation in the sloping uplands of Asia is a serious problem that threatens the sustainability of agriculture. Although several soil conservation technologies have been developed and promoted, their adoption has not been widespread. A micro-economic analysis of adoption of contour hedgerows by upland farmers in the Philippines is conducted to identify the factors that determine adoption. The empirical results

Ma. Lucila A. Lapar; Sushil Pandey

1999-01-01

11

Controlled drainage on a cultivated peat soil  

NASA Astrophysics Data System (ADS)

Controlled drainage can delay the decomposition of organic material in peat soils, as high water table means a thin oxidized layer in the soil surface. Therefore, greenhouse gas emissions, and mineralization of nutrients will be decreased. There will also be less outflow from the field. These mean less nutrient leaching. However, controlled drainage systems may not always manage to keep the water table on the desired level in practical field conditions. In this study, the water tables in two controlled drainage systems were monitored on a cultivated peat soil in southern Finland around a year. Results show how the water table reacts to the changes of the water height in the control wells, and to the surrounding weather conditions. The data collection is still going on.

Myllys, Merja; Regina, Kristiina

2014-05-01

12

Is the blocking of drainage channels in upland peats an effective means of reducing water colour at catchment scales?  

NASA Astrophysics Data System (ADS)

Catchments with extensive peat coverage commonly have high fluvial dissolved organic carbon (DOC) concentrations. Long term water colour (a proxy for DOC) records from the River Tees, UK, indicate an increasing water colour trend, a trend that has been recognised in series of UK streams. It is considered that the release of carbon from these areas can be related to changes in water table depth in the soil profile with DOC being produced within the aerobic layer of the peat. The drainage of upland peatlands, by the cutting of open drainage channels was common practice in Northern England. The practice succeeded in lowering the water table but led to an increase in recorded DOC concentration leaving the catchment. The blocking of these channels has thus been proposed as a means of peat restoration. The reduction in drainage capacity will cause increases in the water table, rewetting the peat and reducing losses in carbon. This study aims to assess the effectiveness of drain blocking as a method of reducing DOC levels at the catchment scale. Also the effects of blocking on the water balance and any changes in the flow pathways of water through the catchments post blocking will be determined via fingerprinting studies. A series of nested blocked and unblocked catchments were studied in Upper Teesdale, Northern England. Drain water samples at nine localities were taken at least daily. These sites were located such that individual drains could be monitored in the context of a larger catchment. Water table depth, flow and weather parameters were recorded along with the collection of run off and soil water samples. A detailed sampling programme was undertaken in which a series of drains were studied in the 12 months prior to blocking and the 12 months after. Results indicate that the blocking of zero order drainage channels leads to a decrease in DOC export on an individual drain scale. However, this is due to a reduction in water yield rather than concentration. Concentrations are seen to rise by a small yet statistically significant amount in blocked zero order streams. The effect at a larger scale is more complex. Annual export values in the unblocked control catchment show a rise from zero to first order streams indicating that water is being added to the system at this scale from external spatially variable sources. This pattern is also recognised in the blocked catchment. The DOC concentration record in blocked drains at this larger scale however indicated a reduction relative to the unblocked catchment. This reduction points to a change in flow pathways post blocking as highly coloured water re-navigates its way downstream.

Turner, Kate; Worrall, Fred

2010-05-01

13

Phosphorus management for perennial crops in central Amazonian upland soils  

Microsoft Academic Search

The present contribution discusses the soil P status of central Amazonian upland soils, the effects of tree crops on soil P availability and the factors controlling soil P cycling in land use systems with tree crops. Soil fertility management has to target the prevalent P deficiency by adequate P fertilization, especially in southern and northern municipalities of central Amazônia where

Johannes Lehmann; Manoel da Silva Cravo; Jeferson Luiz Vasconselos de Macêdo; Adônis Moreira; Götz Schroth

2001-01-01

14

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

15

Metatranscriptomic analysis of arctic peat soil microbiota.  

PubMed

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; Urich, Tim; Svenning, Mette M

2014-09-01

16

Aerobic and microaerophilic actinomycetes of typical agropeat and peat soils  

NASA Astrophysics Data System (ADS)

A high number (from tens of thousands to millions of CFU/g of soil) of actinomycetes and a high diversity of genera were found in typical peat and agropeat soils. Agricultural use increases the number and diversity of the actinomycete complexes of the peat soils. In the peat soils, the actinomycete complex is represented by eight genera: Streptomyces, Micromonospora, Streptosporangium, Actinomadura, Microbispora, Saccharopolyspora, Saccharomonospora, and Microtetraspora. A considerable share of sporangial forms in the actinomycete complex of the peat soils not characteristic of the zonal soils was revealed. The number of actinomycetes that develop under aerobic conditions is smaller by 10-100 times than that of aerobic forms in the peat soils. Among the soil actinomycetes of the genera Streptomyces, Micromonospora, Streptosporangium, Actinomadura, Microbispora, and Microtetraspora, the microaerophilic forms were found; among the Saccharopolyspora and Saccharomonospora, no microaerophilic representatives were revealed.

Zenova, G. M.; Gryadunova, A. A.; Pozdnyakov, A. I.; Zvyagintsev, D. G.

2008-02-01

17

Climate mitigation scenarios of drained peat soils  

NASA Astrophysics Data System (ADS)

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

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

2014-05-01

18

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

19

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...

20

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

NASA Astrophysics Data System (ADS)

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

Mezhibor, Antonina; Podkozlin, Ivan

2013-04-01

21

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

22

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

23

PRESERVATION OF PEAT SOIL BY CULTIVATION OF PERENNIAL HERBAGE CROPS  

Microsoft Academic Search

On a peat-soil of the reclaimed Hula Valley swamp containing 30-40% organic matter,, 1.5% of N, C\\/N ratio of 10 and pH = 6-6.5 three varieties of Guinea grass, alfalfa and Rhodes grass were grown. The aim of the research was to preserve the peat-soil from the prevailing aerobic oxidation, wind and water erosion and minimize the typical nitrate accumulation,

Dan Levanon; Israel Levin

24

DIVISION S-10--WETLAND SOILS Carbon Accumulation and Storage in Mineral Subsoil beneath Peat  

E-print Network

DIVISION S-10--WETLAND SOILS Carbon Accumulation and Storage in Mineral Subsoil beneath Peat Tim R subsoil (Turunen and Moore, 2003). TheyWe showed that sandy subsoils beneath peat near Ramsey Lake conditions beneath the peat. soils beneath the forest, those beneath the peat contained similar In this paper

Moore, Tim

25

The effect of soil moisture on thermal properties in some typical Japanese upland soils  

Microsoft Academic Search

The effects of soil moisture on thermal properties of some typical Japanese upland soils were studied. Thermal properties which were studied here were volumetric heat capacity, thermal conductivity, and thermal diffusivity. Sample taken at various horizons of volcanic ash (Yachimata) soil, alluvial (Kiyosu) soil, and diluvial (Toyoilashi) soil were used. The results are summarized as follows. 1) Volumetric heat capacity

Tatsuaki Kasubuchi

1975-01-01

26

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

27

Design and performance of EPS footing for lightweight farm structure on peat soil  

Microsoft Academic Search

The objective of this research project was to find a potential replacement for the conventional pile foundation principally for peat soil. It is fundamentally meant for lightweight and impermanent agricultural farm structures. Preceding the design and development of the foundation the physical characteristics of the in-situ peat such as; peat depth, soil consolidation, soil compressibility, water table, liquid limit, soil

Mohammad Abdullah; B B K Huat; Rezuwan Kamaruddin; Abu Kasim Ali; Y Duraisamy

2007-01-01

28

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

NASA Astrophysics Data System (ADS)

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

Gao, Jihui; Holden, Joseph; Kirkby, Mike

2014-05-01

29

Peat  

USGS Publications Warehouse

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

Jasinski, S.M.

2006-01-01

30

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

31

[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

32

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

33

Peat  

USGS Publications Warehouse

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

Jasinski, S.M.

2000-01-01

34

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

35

Influence of water table level and soil properties on emissions of greenhouse gases from cultivated peat soil  

Microsoft Academic Search

A lysimeter method using undisturbed soil columns was used to investigate the effect of water table depth and soil properties on soil organic matter decomposition and greenhouse gas (GHG) emissions from cultivated peat soils. The study was carried out using cultivated organic soils from two locations in Sweden: Örke, a typical cultivated fen peat with low pH and high organic

Ö. Berglund; K. Berglund

2011-01-01

36

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

37

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

NASA Astrophysics Data System (ADS)

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

Tuukkanen, Tapio; Marttila, Hannu; Kløve, Bjørn

2014-04-01

38

Soil oxygen availability and biogeochemistry along rainfall and topographic gradients in upland wet tropical forest soils  

Microsoft Academic Search

We measured soil oxygen concentrations at 10 and 35 cm depths and indices of biogeochemical cycling in upland forest soils along a rainfall and elevation gradient (3500–5000 mm y-1; 350–1050 masl) and along topographic gradients (ridge to valley, ~150 m) in the Luquillo Experimental Forest, Puerto Rico. Along the rainfall gradient, soil O2 availability decreased significantly with increasing annual rainfall,

WHENDEE L. SILVER; A. E. Lugo; M. Keller

1999-01-01

39

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

E-print Network

Transport of lead and diesel fuel through a peat soil near Juneau, AK: a pilot study Julian Deissa; accepted 6 February 2004 Abstract A set of peat column experiments was used to determine the transport-bearing stream 250 m from the site. Three pairs of peat columns were extracted from the rifle range for analysis

Walter, M.Todd

40

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

41

Peat  

USGS Publications Warehouse

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

Jasinski, S.M.

2003-01-01

42

Peat  

USGS Publications Warehouse

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

Jasinski, S.M.

1998-01-01

43

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

44

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

NASA Astrophysics Data System (ADS)

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

Turner, Kate; Worrall, Fred

2010-05-01

45

Peat  

USGS Publications Warehouse

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

Apodaca, L.E.

2011-01-01

46

Peat  

USGS Publications Warehouse

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

Apodaca, L.E.

2013-01-01

47

Peat  

USGS Publications Warehouse

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

Apodaca, L.E.

2012-01-01

48

Peat  

USGS Publications Warehouse

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

Apodaca, L.E.

2010-01-01

49

Measurement and Modelling of Real Evapotranspiration In Peat Soils  

NASA Astrophysics Data System (ADS)

A new methodology was created to determine water balance parameters of peat soils using easy installable groundwater lysimeters. With the experimental setup real evap- otranspiration and capillary rise was measured at different groundwater levels in a cultivated fen. The data was used for developement, calibration and validation of a numeric water balance model. The simulation program solves the one dimensional Darcy equation for variably saturated water flow. The model considers the hydraulic properties of soils. The Penman-Monteith equation was used to calculate the real evapotranspiration. The necessary canopy resistance of phalaris arundinacea for the Penman-Monteith equation was estimated from field measurements. The field mea- surements show that the canopy resistance of phalaris arundinacea is dependent of soil-water potential in the root zone. The model considers this fact.

Schwaerzel, K.; Wessolek, G.

50

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

51

Actinomycetal complexes in drained peat soils of the taiga zone upon pyrogenic succession  

NASA Astrophysics Data System (ADS)

The number and diversity of actinomycetes in peat soils vary in dependence on the stage of pyrogenic succession. In the cultivated peat soil, the number of actinomycetes after fires decreases by three-four times, mainly at the expense of acidophilic and neutrophilic groups. An increase in the number of mycelial prokaryotes (at the expense of alkaliphilic forms) is seen on the fifth year of functioning of the pyrogenic peat soil. The species diversity of streptomycetes in peat soils also decreases after fires. An increase in the range of streptomycetal species at the expense of neutrophilic and alkaliphilic forms takes place on the fifth year of the pyrogenic succession. Parameters of the actinomycetal complex—the population density, species composition, and ecological features—are the criteria whose changes allow us to judge the state of peat soils in the course of their pyrogenic succession.

Zenova, G. M.; Glushkova, N. A.; Bannikov, M. V.; Shvarov, A. P.; Pozdnyakov, A. I.; Zvyagintsev, D. G.

2008-04-01

52

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

53

Application of ground-penetrating radar to the identification of subsurface piping in blanket peat  

Microsoft Academic Search

Natural soil pipes are common and significant in upland blanket peat catchments yet there are major problems in finding and defining the subsurface pipe networks. This is particularly important because pipeflow can contribute a large proportion of runoff to the river systems in these upland environments and may significantly influence catchment sediment and solute yields. Traditional methods such as digging

J. Holden; T. P. Burt; M. Vilas

2002-01-01

54

Can carbon offsetting pay for upland ecological restoration?  

NASA Astrophysics Data System (ADS)

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.

Worrall, F.

2012-04-01

55

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

56

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

E-print Network

perturbation (Tennessee Valley (TV)) versus clay-rich soil creep (Black Diamond (BD)). The average SOC erosionErosion of upland hillslope soil organic carbon: Coupling field measurements with a sediment July 2005. [1] Little is known about the role of vegetated hillslope sediment transport in the soil C

Heimsath, Arjun M.

57

Dissolved organic carbon in soil solution of peat-moorsh soils on Kuwasy Mire  

NASA Astrophysics Data System (ADS)

Key words: peat-moorsh soils, soil solution, dissolved organic carbon (DOC), temperature of soil, redox potential. The objective this study was the dissolved organic carbon concentration (DOC) in soil solution on the background of soil temperature, moisture and redox potential. The investigations were localized on the area of drained and agricultural used Kuwasy Mire, which are situated in the middle basin of Biebrza River, in North-East Poland. Research point was placed on a low peat soil of 110 cm depth managed as extensive grassland. The soil was recognized as peat-moorsh with the second degree of the moorshing process (with 20 cm of moorsh layer). The ceramic suction cups were installed in three replications at 30 cm depth of soil profile. The soil solution was continuously sampled by pomp of the automatic field station. The successive samples comprised of solution collected at the intervals of 21 days. Simultaneously, at the 20, 30 and 40 cm soil depths the measurements of temperature and determination of soil moisture and redox potential were made automatically. The mean twenty-four hours data were collected. The concentrations of DOC were determined by means of the flow colorimeter using the Skalar standard methods. Presented observations were made in 2001-2006. Mean DOC concentration in soil solution was 66 mg.dm-3 within all research period. A significant positive correlation between studied compound concentration and temperature of soil at 30 cm depth was observed; (correlation coefficient - r=0.55, number of samples - n=87). The highest DOC concentrations were observed during the season from July to October, when also a lower ground water level occurred. The DOC concentration in soil solution showed as well a significant correlation with the soil redox potential at 20 cm level. On this depth of describing soil profile a frontier layer between moorshing layer and peat has been existed. This layer is the potentially most active in the respect to biochemical transformation. On the other hand it wasn't possible to shown dependences on the DOC concentration from soil moisture. That probably results from a huge water-holding capacity of these type of peat soils, which are keeping a high moisture content even at a long time after decreasing of the groundwater table.

Jaszczy?ski, J.; Sapek, A.

2009-04-01

58

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

NASA Astrophysics Data System (ADS)

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 quantitatively link the degree of chemical weathering in bedrock-derived soils and underlying saprolite to the rate of soil production from the same saprolite. We dug twenty-three soil pits of varying depths into a convex hillslope near Mount Vision, Point Reyes National Seashore, California. Pits were dug manually to refusal or to the saprolite-soil interfaces. We sampled soil at regular intervals for short-lived isotope analyses and saprolite from just below the soil-saprolite interface. The saprolite samples underwent analyses for trace metals and labile oxides by inductively coupled plasma-optical emissions spectrometry and x-ray diffraction. A high-resolution topographic survey and previous work quantifying soil production rates with cosmogenic nuclides allows us to connect transport processes with chemical weathering rates. Saprolite bulk density and other field parameters were measured for volumetric strain analysis. We used the Chemical Index of Alteration (CIA) (Kirkwood and Nesbitt, 1992) to quantify the degree of chemical weathering in both unweathering bedrock and weathered saprolite. Initial results indicate relative enrichment of resistant trace metals such as zircon at shallow sample depths. We find that zirconium at the soil-saprolite boundary is on average 35% less weathered than the saprolite in the 150 cm. beneath the boundary. Weathering at the soil-saprolite boundary as defined by the CIA is 50% more weathered than the parent material. CIA values for unweathered and weathered material agree well with previous published material and indicate a tentative method of quantifying the coupling between chemical and mechanical weathering.

Burke, B. C.

2002-12-01

59

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

E-print Network

front. The results show that moisture content controls peat ignition and that moisture contents below 125% (in dry base) are required. The severity of the smouldering peat on the soil has been quantified in terms of temperature vs. residence-time curves...

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

60

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

61

Implications of changing from grazed or semi-natural vegetation to forestry for carbon stores and fluxes in upland organo-mineral soils in the UK  

NASA Astrophysics Data System (ADS)

In the UK, as organo-mineral soils are a significant store of soil organic carbon (SOC), they may become increasingly favoured for the expansion of upland forestry. It is important, therefore, to assess the likely impacts on SOC of this potentially major land use change. Currently, these assessments rely on modelling approaches which assume that afforestation of organo-mineral soils is "carbon neutral". This review evaluates this assumption in two ways. Firstly, UK information from the direct measurement of SOC change following afforestation is examined in the context of international studies. Secondly, UK data on the magnitude and direction of the major fluxes in the carbon cycle of semi-natural upland ecosystems are assessed to identify the likely responses of the fluxes to afforestation of organo-mineral soils. There are few directly relevant measurements of SOC change following afforestation of organo-mineral soils in the UK uplands but there are related studies on peat lands and agricultural soils. Overall, information on the magnitude and direction of change in SOC with afforestation is inconclusive. Data on the accumulation of litter beneath conifer stands have been identified but the extent to which the carbon held in this pool is incorporated into the stable soil carbon reservoir is uncertain. The effect of afforestation on most carbon fluxes is small because the fluxes are either relatively minor or of the same magnitude and direction irrespective of land use. Compared with undisturbed moorland, particulate organic carbon losses increase throughout the forest cycle but the data are exclusively from plantation conifer forests and in many cases pre-date current industry best practice guidelines which aim to reduce such losses. The biggest uncertainty in flux estimates is the relative magnitude of the sink for atmospheric carbon as trees grow and mature compared with that lost during site preparation and harvesting. Given the size of this flux relative to many of the others, this should be a focus for future carbon research on these systems.

Reynolds, B.

2007-01-01

62

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

PubMed

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

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

2011-05-01

63

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...

64

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...

65

Linking yields of upland rice in shifting cultivation to fallow length and soil properties  

Microsoft Academic Search

In many tropical cultivation systems, fallowing is a prerequisite for maintaining long-term plant-available nutrient pools and crop yields. This study examines the relationships between length of fallows, soil nutrient levels and yields of upland rice in a shifting cultivation system in Sarawak, Malaysia. A farmer managed field trial included 12 fields cultivated by means of slash and burn. Sites had

Thilde Bech Bruun; Ole Mertz; Bo Elberling

2006-01-01

66

Buffer capacities of podzolic and peat gleyic podzolic soils to sulfuric and nitric acids  

Microsoft Academic Search

Soil samples from the main genetic horizons of pale podzolic and peat gleyic podzolic soils from the Central Forest Reserve\\u000a were subjected to a continuous potentiometric titration by sulfuric and nitric acids. The sulfate sorption capacity was determined\\u000a in soil mineral horizons. The buffer capacity of mineral horizons of both soils to sulfuric acid was found to be higher than

N. B. Kuznetsov; S. A. Alekseeva; G. V. Shashkova; T. Ya. Dronova; T. A. Sokolova

2007-01-01

67

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

68

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

69

Peat soil flows in Bahía del Buen Suceso, Tierra del Fuego (Argentina)  

NASA Astrophysics Data System (ADS)

On the southeastern edge of Tierra del Fuego, a mountainous area with a cold humid oceanic climate, peat soils cover not only flat areas but also steep hillslopes under an evergreen Nothofagus betuloides forest. Peat flows in the form of chutes are very frequent on these hillslopes. Some data were gathered on the field for 11 of these movements and from aerial photographs for 21 of them. The results suggest that peat soils become unstable when thickness exceeds a critical value which depends on the slope. This critical slope depends on the altitude and aspect regardless of soil thickness. A temporal analysis carried out by tree-ring counting demonstrated that the occurrence of these movements is not random though there are some periods of higher hazard, the probable triggering mechanisms being heavy snowfalls or earthquakes.

Gallart, Francesc; Clotet-Perarnau, Núria; Bianciotto, Oscar; Puigdefàbregas, Joan

1994-05-01

70

Rhizogenic Fe–C redox cycling: a hypothetical biogeochemical mechanism that drives crustal weathering in upland soils  

Microsoft Academic Search

Field-scale observations of two upland soils derived from contrasting granite and basalt bedrocks are presented to hypothesize\\u000a that redox activity of rhizospheres exerts substantial effects on mineral dissolution and colloidal translocation in many\\u000a upland soils. Rhizospheres are redox-active microsites and in the absence of O2, oxidation of rhizodeposits can be coupled by reduction of redox-active species such as Fe, a

Ryan L. Fimmen; Daniel de B. Richter; Dharni Vasudevan; Mark A. Williams; Larry T. West

2008-01-01

71

Buffer capacities of podzolic and peat gleyic podzolic soils to sulfuric and nitric acids  

NASA Astrophysics Data System (ADS)

Soil samples from the main genetic horizons of pale podzolic and peat gleyic podzolic soils from the Central Forest Reserve were subjected to a continuous potentiometric titration by sulfuric and nitric acids. The sulfate sorption capacity was determined in soil mineral horizons. The buffer capacity of mineral horizons of both soils to sulfuric acid was found to be higher than that to the nitric acid. This is explained by the sorption of sulfates via the mechanism of ligand exchange with the release of hydroxyl groups from the surfaces of Fe and Al hydroxide particles and edge faces of clay crystallites. The buffer capacity of organic horizons of the pale podzolic soil to sulfuric acid proved to be higher than that to nitric acid; in organic horizons of the peat gleyic podzolic soil, the buffer capacity to sulfuric acid was lower than that to nitric acid. The reasons for this phenomenon have yet to be investigated.

Kuznetsov, N. B.; Alekseeva, S. A.; Shashkova, G. V.; Dronova, T. Ya.; Sokolova, T. A.

2007-04-01

72

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

73

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

74

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

NASA Astrophysics Data System (ADS)

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

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

2012-04-01

75

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

76

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

PubMed

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

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

2015-01-01

77

Soil erosion on upland areas by rainfall and overland flow  

Technology Transfer Automated Retrieval System (TEKTRAN)

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

78

Carbon flow in an upland grassland: effect of liming on the flux of recently photosynthesized carbon to rhizosphere soil  

Microsoft Academic Search

The effect of liming on the flow of recently photosynthesized carbon to rhizosphere soil was studied using 13 CO2 pulse labelling, in an upland grassland ecosystem in Scotland. The use of 13 C enabled detection, in the field, of the effect of a 4-year liming period of selected soil plots on C allocation from plant biomass to soil, in comparison

J. I GNACIO; R ANGEL-CASTRO; I. P ROSSER; C HARLIE; N ICK O STLE; P HIL; K E N K I L L H A Mw

2004-01-01

79

Contrasting denitrifier communities relate to contrasting N2O emission patterns from acidic peat soils in arctic tundra  

PubMed Central

Cryoturbated peat circles (that is, bare surface soil mixed by frost action; pH 3–4) in the Russian discontinuous permafrost tundra are nitrate-rich ‘hotspots' of nitrous oxide (N2O) emissions in arctic ecosystems, whereas adjacent unturbated peat areas are not. N2O was produced and subsequently consumed at pH 4 in unsupplemented anoxic microcosms with cryoturbated but not in those with unturbated peat soil. Nitrate, nitrite and acetylene stimulated net N2O production of both soils in anoxic microcosms, indicating denitrification as the source of N2O. Up to 500 and 10?? nitrate stimulated denitrification in cryoturbated and unturbated peat soils, respectively. Apparent maximal reaction velocities of nitrite-dependent denitrification were 28 and 18?nmol N2O?gDW?1?h?1, for cryoturbated and unturbated peat soils, respectively. Barcoded amplicon pyrosequencing of narG, nirK/nirS and nosZ (encoding nitrate, nitrite and N2O reductases, respectively) yielded ?49?000 quality-filtered sequences with an average sequence length of 444?bp. Up to 19 species-level operational taxonomic units were detected per soil and gene, many of which were distantly related to cultured denitrifiers or environmental sequences. Denitrification-associated gene diversity in cryoturbated and in unturbated peat soils differed. Quantitative PCR (inhibition-corrected per DNA extract) revealed higher copy numbers of narG in cryoturbated than in unturbated peat soil. Copy numbers of nirS were up to 1000 × higher than those of nirK in both soils, and nirS nirK?1 copy number ratios in cryoturbated and unturbated peat soils differed. The collective data indicate that the contrasting N2O emission patterns of cryoturbated and unturbated peat soils are associated with contrasting denitrifier communities. PMID:22134649

Palmer, Katharina; Biasi, Christina; Horn, Marcus A

2012-01-01

80

The effect of drain blocking on the dissolved organic carbon (DOC) budget of an upland peat catchment in the UK  

NASA Astrophysics Data System (ADS)

SummaryExtensive drainage of UK peatlands has been associated with dehydration of the peat, an increase in water colour and a loss of carbon storage. It has been considered that the blocking of these drainage channels represents a means of peat restoration and a way of reducing dissolved organic carbon (DOC) losses to surface waters. This study aimed to assess the effectiveness of drain blocking at both an individual drain scale and at a larger catchment scale (up to 1 km2). A series of blocked and unblocked catchments were studied in Upper Teesdale, Northern England. A detailed sampling programme was undertaken in which a series of drains were studied in the 12 months prior to and post blocking in comparison to a set of drains that were left unblocked and a catchment of similar scale where there had never been drainage. These stream networks were monitored for both their DOC concentration and export (flux per unit area). The results show that: For DOC concentrations, a significant decline due to drain-blocking was only found at the first order scale when considered relative to control and relative to a pre-blocking period; drain blocking significantly reduces DOC export by reducing water yield in the drain and that the size of this DOC export reduction declines with increasing scale from 9.2% on zero order drains to 2.2% on first order drains; a linear relationship exists between DOC export and water yield at the zero order scale but this relationship becomes more complex at the first order scale as the relationship takes on the characteristics of a mixing model reflecting the effect of changing water sources with scale and providing evidence of the existence of flow bypassing drain blocks. The results suggest that effects of drain blocking decrease with increasing scale and that the presence of bypass flow around zero order blockages may limit the success of drain blocking as a method of reducing DOC loss as scale increases.

Turner, E. K.; Worrall, F.; Burt, T. P.

2013-02-01

81

Nutritional characteristics of sago palm and oil palm in tropical peat soil  

Microsoft Academic Search

To make clear the nutritional characteristics of sago palm (Metroxylon sagu Rottb.) and oil palm (Elaeis guineensin Jacq.) grown in tropical peat soil, minerals concentration, organic compounds concentration, and photo?synthetic rate were estimated, and the obtained results were as follows. Since, the nitrogen (N), phosphorus (P), calcium (Ca), magnesium (Mg), and sodium (Na) concentration in mature leaves and trunk were

Mina Matsumoto; Mitsuru Osaki; Tanit Nuyim; Apichart Jongskul; Yoshiaki Kitaya; Masaru Urayama; Toshihiro Watanabe; Takeshi Kawamukai; Takuji Nakamura; Chairatna Nilnond; Takuro Shinano; Toshiaki Tadano

1998-01-01

82

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

PubMed

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

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

2013-01-01

83

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

84

RESPONSE OF UPLAND RICE GENOTYPES TO SOIL ACIDITY  

Technology Transfer Automated Retrieval System (TEKTRAN)

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

85

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

86

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

NASA Astrophysics Data System (ADS)

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

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

2013-01-01

87

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

88

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

89

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...

90

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...

91

Effect of pesticides on cellulose degradation in soil under upland and flooded conditions  

Microsoft Academic Search

The effect of pesticides on cellulose degradation in a soil was estimated by incubation experiments under upland conditions, transitional flooded conditions from aerobic to anaerobic, and fully anaerobic flooded conditions. Pesticides examined were trichlamide [(RS)-N-(1-butoxy-2,2,2-trichIoroethyl)salicyl-amide], chlorothalonil (TPN, 2,4,5,6-tetrachloro-1,3-isophthalonitrile), quin-tozene (PCNB, pentachloronitrobenzene), and hymexazol (3-hydroxy-5-meth-ylisoxazol) as fungicides, paraquat (1,1?-dimethyl-4,4?-bipyridium dichloride), thiobencarb (benthiocarb, S-p-chlorobenzyldiethyl thiocarbamate), propanil (DCPA, 3?,4?-dichloropropionanilide), and butachlor [2-chloro-2?,6?-diethyI-N-(butoxymethyl)acetoanilide] as

Arata Katayama; Shozo Kuwatsuka

1991-01-01

92

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

2015-03-01

93

Bare soil and reed canary grass ecosystem respiration in peat extraction sites in Eastern Finland  

NASA Astrophysics Data System (ADS)

This paper reports chamber measurements of ecosystem respiration (ER) from reed canary grass (Phalaris arundinacea L.) (RCG) cultivation made during 2004 and 2005 and respiration rates from an adjacent, bare peat extraction site. Annually, the RCG site released 1465 g in 2004 and 1968 g CO2 m-2 in 2005. The peat extraction site, however, emitted 498 g in 2004 and 264 g CO2 m-2 in 2005. Heterotrophic respiration accounted for about 45% of the RCG ER. Temperature explained 75-88% of the variation in 2005 RCG heterotrophic respiration. Autotrophic respiration was the dominant component of ER and it followed a similar seasonal pattern as the living (green) biomass. RCG heterotrophic respiration was related to soil temperature in interaction with soil volumetric water content and seasonal rainfall distribution. It explained 79 and 47% of the variation in the bare soil respiration from the peat extraction site during 2004 and 2005 snow free periods, respectively. Compared to other ecosystems, emissions from RCG were lower indicating that the RCG is a promising after use option in organic soils.

Shurpali, N. J.; Hyvönen, N. P.; Huttunen, J. T.; Biasi, C.; Nykänen, H.; Pekkarinen, N.; Martikainen, P. J.

2008-04-01

94

Autonomous ground penetrating radar (GPR) measurements for exploring biogenic gas dynamics of peat soils in a northern peatland  

NASA Astrophysics Data System (ADS)

It is widely accepted that northern peat soils are responsible for up to 10% of methane flux to the atmosphere yet act as a net sink for as much as 75% of the global mass of atmospheric carbon. A better understanding of the processes by which peat soils store and release carbon products must be gained in order to more accurately model the contributions that peatlands make to global atmospheric carbon budgets. Rapid ebullition events of biogenic methane and carbon dioxide gases from peat soils are currently not well understood, particularly since the timing of the releases are poorly constrained. Ground penetrating radar (GPR) is a geophysical tool that has successfully been used in the past to non-invasively investigate the release of biogenic gasses from peat soils. In the work presented here, measurement frequency is expanded by including daily arrays of common offset and common midpoint GPR measurements combined with hourly autonomous GPR measurements to investigate biogenic gas dynamics during times of variable atmospheric pressure in a northern peatland in Maine. Geophysical data were supported by peat matrix deformation measurements using terrestrial LiDAR (TLS) and direct gas flux measurements using gas traps combined with time-lapse cameras at the sub-daily scale. A vertical array of moisture probes was also used to further constrain GPR measurements. Results from this study show the viability of autonomous GPR methods for improving temporal resolution of geophysical data in order to better understand the dynamics of biogenic gas releases from peat soils.

Wright, W. J.; Comas, X.; Heij, G.; Slater, L. D.; Schafer, K. V.; Reeve, A. S.

2012-12-01

95

Dissolved organic carbon and disinfection by-product precursor release from managed peat soils.  

PubMed

A wetland restoration demonstration project examined the effects of a permanently flooded wetland on subsidence of peat soils. The project, started in 1997, was done on Twitchell Island, in the Sacramento-San Joaquin Delta of California. Conversion of agricultural land to a wetland has changed many of the biogeochemical processes controlling dissolved organic carbon (DOC) release from the peat soils, relative to the previous land use. Dissolved organic C in delta waters is a concern because it reacts with chlorine, added as a disinfectant in municipal drinking waters, to form carcinogenic disinfection byproducts (DBPs), including trihalomethanes (THMs) and haloacetic acids (HAAs). This study explores the effects of peat soil biogeochemistry on DOC and DBP release under agricultural and wetland management. Results indicate that organic matter source, extent of soil organic matter decomposition, and decomposition pathways all are factors in THM formation. The results show that historical management practices dominate the release of DOC and THM precursors. However, within-site differences indicate that recent management decisions can contribute to changes in DOC quality and THM precursor formation. Not all aromatic forms of carbon are highly reactive and certain environmental conditions produce the specific carbon structures that form THMs. Both HAA and THM precursors are elevated in the DOC released under wetland conditions. The findings of this study emphasize the need to further investigate the roles of organic matter sources, microbial decomposition pathways, and decomposition status of soil organic matter in the release of DOC and DBP precursors from delta soils under varying land-use practices. PMID:15074797

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

2004-01-01

96

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

USGS Publications Warehouse

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

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

2004-01-01

97

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

98

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

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

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

1999-01-01

99

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

100

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

101

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

USGS Publications Warehouse

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

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

2008-01-01

102

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

103

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

PubMed

The diversity of grassland in upland areas of Czech Republic was studied on selected soil characteristics of these biotopes. In the first phase, 44 soil characteristics were studied and mutual correlations were found between many of them. In the following phase characteristics were chosen which correlated most with other soil characteristics and, at the same time, were easy to evaluate in practise. A great number of correlations were also evidenced between many soil characteristics and the content of humus and nitrogen, which are closely linked to organic matter in soil. In studying these characteristics on selected areas with different types of grassland and consequential cluster analysis and further evaluation, the grassland plots were divided into three groups, from newly established vegetation to species-rich communities. Non-parametric analysis was carried out on the results and a statistically significant difference was proved between the species rich and poorvegetation and carbon and nitrogen content of the soil. Slightly different humus quality (higher amount of HA) was also found under richer vegetation. These results show that at 0-20 cm layer, 58.9 tonnes of carbon ha?¹ was measured under species-poor pastureland and 106.1 tonnes of carbon ha under species-rich vegetation. The results showed that besides supporting species diversity, the described quality change can also be important for carbon sequestration. The difference of about 40-50 tonnes of carbon ha and converting 10% of grassland in the Czech Republic to species-rich vegetation would mean sequestration of about 3.9 Mt carbon. If only agroenvironmentally subsidized areas are converted, carbon sequestration in such vegetation could amountto 1.7 Mt. PMID:24812999

Sarapatka, B; Cizkova, S

2014-05-01

104

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

NASA Astrophysics Data System (ADS)

Little is known about the role of vegetated hillslope sediment transport in the soil C cycle and soil-atmosphere C exchange. We combined a hillslope sediment transport model with empirical soil C measurements to quantify the erosion and temporal storage of soil organic carbon (SOC) within two grasslands in central California. The sites have contrasting erosional mechanisms: biological perturbation (Tennessee Valley (TV)) versus clay-rich soil creep (Black Diamond (BD)). The average SOC erosion rates from convex slopes were 1.4-2.7 g C m-2 yr-1 at TV and 5-8 g C m-2 yr-1 at BD, values that are <10% of above ground net primary productivity (ANPP) at both sites. The eroded soil accumulates on depositional slopes. The long term SOC accumulation (or C sink) rates are ˜1.9 g C m-2 yr-1 in the TV hollow and 1.7-2.8 g C m-2 yr-1 in the BD footslope. We found that the hillslope C sink is driven primarily by the burial of in situ plant production rather than preservation of eroded SOC, a finding that differs from existing hypotheses. At TV, the net sequestration of atmospheric C by long-term hollow evacuation and refilling depends on the fate of the C exported from the zero order watershed. This study suggests that erosion and deposition are coupled processes that create a previously unrecognized C sink in undisturbed upland watersheds, with a potential to substantially affect the global C balance presently, and over geological timescales.

Yoo, Kyungsoo; Amundson, Ronald; Heimsath, Arjun M.; Dietrich, William E.

2005-09-01

105

Exploring the Links Between Topography, Riparian Peat Soils and Stream Water Quality in the Boreal Krycklan Catchment, Northern Sweden  

NASA Astrophysics Data System (ADS)

The riparian zone has been hypothesized to be a major control on stream water quality in boreal catchments with relatively shallow flowpaths. If this is true, then the soils in the riparian zone and their interaction with lateral flows should hold the key to understanding landscape scale patterns in stream water quality. However, little is known about the structure of riparian soils as standard soil maps are too coarse to represent the heterogeneity of riparian soils. In this study we present results from a soil and vegetation survey of 180 transects through the riparian zone of a 68 km2 forested catchment in Northern Sweden. Peat, a variable that is commonly found to correlate with stream water quality, was found in the majority of transects, even in locations where soil maps did not indicate any peat. Despite significant small scale variability, general patterns of peat thickness emerged when aggregating the transect data. Combining the survey data with flow pathways derived from a high-resolution DEM showed that a considerable part of the catchment drains through this riparian peat. Topographic controls on stream chemistry might be explained by the link between topography and peat; however, the relationship between peat thickness and terrain indices including slope, topographic wetness index and elevation-above-stream was not always clear due to the large small scale variability found in the riparian zone. However, promising results were obtained when combining topographically derived flow pathways and representative samples of soil water chemistry from the riparian zone and comparing this information with stream water chemistry.

Grabs, T.; Bishop, K.; Seibert, J.; Laudon, H.

2008-12-01

106

Effect of Sheep Urine Deposition on the Bacterial Community Structure in an Acidic Upland Grassland Soil  

PubMed Central

The effect of the addition of synthetic sheep urine (SSU) and plant species on the bacterial community composition of upland acidic grasslands was studied using a microcosm approach. Low, medium, and high concentrations of SSU were applied to pots containing plant species typical of both unimproved (Agrostis capillaris) and agriculturally improved (Lolium perenne) grasslands, and harvests were carried out 10 days and 50 days after the addition of SSU. SSU application significantly increased both soil pH (P < 0.005), with pH values ranging from pH 5.4 (zero SSU) to pH 6.4 (high SSU), and microbial activity (P < 0.005), with treatment with medium and high levels of SSU displaying significantly higher microbial activity (triphenylformazan dehydrogenase activity) than treatment of soil with zero or low concentrations of SSU. Microbial biomass, however, was not significantly altered by any of the SSU applications. Plant species alone had no effect on microbial biomass or activity. Bacterial community structure was profiled using bacterial automated ribosomal intergenic spacer analysis. Multidimensional scaling plots indicated that applications of high concentrations of SSU significantly altered the bacterial community composition in the presence of plant species but at different times: 10 days after application of high concentrations of SSU, the bacterial community composition of L. perenne-planted soils differed significantly from those of any other soils, whereas in the case of A. capillaris-planted soils, the bacterial community composition was different 50 days after treatment with high concentrations of SSU. Canonical correspondence analysis also highlighted the importance of interactions between SSU addition, plant species, and time in the bacterial community structure. This study has shown that the response of plants and bacterial communities to sheep urine deposition in grasslands is dependent on both the grass species present and the concentration of SSU applied, which may have important ecological consequences for agricultural grasslands. PMID:17088382

Rooney, Deirdre; Kennedy, Nabla; Deering, Louise; Gleeson, Deirdre; Clipson, Nicholas

2006-01-01

107

[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

108

Change in population of 2,4-D degraders in the process of 2,4-D degradation in soils under upland and flooded conditions  

Microsoft Academic Search

The relation between the degradation rate of 2,4-D and the changes in the population of 2,4-D degraders and other microflora in soil was studied under upland and flooded conditions using two types of soils, a mineral soil in Anjo (Anjo soil, Anthrotroaquic Dystrochrept) and a humic volcanic ash soil in Mito (Ibaraki soil, Ando soil, Anthrotroaquic Dystrandept). In all cases

Shozo Kuwatsuka; Noriko Miwa

1989-01-01

109

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

NASA Astrophysics Data System (ADS)

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

Comas, Xavier; Wright, William

2014-08-01

110

Homegardens on Amazonian Dark Earths, Non-anthropogenic Upland, and Floodplain Soils along the Brazilian Middle Madeira River Exhibit Diverging Agrobiodiversity 1  

Microsoft Academic Search

Homegardens on Amazonian Dark Earths, Non-anthropogenic Upland, and Floodplain Soils along the Brazilian Middle Madeira River\\u000a Exhibit Diverging Agrobiodiversity. We test the hypothesis that the agrobiodiversity associated with homegardens on three different soils—upland Amazonian Dark\\u000a Earths (ADE) and Oxisols (OX), and Fluvent Entisols (FL)—commonly found along the middle Madeira River in the municipality\\u000a of Manicoré, Amazonas State, Brazil, is different

James A. Fraser; André B. Junqueira; Charles R. Clement

2011-01-01

111

Use of computed tomography imaging for quantifying coarse roots, rhizomes, peat, and particle densities in marsh soils.  

PubMed

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 quantify wet mass of coarse roots, rhizomes, and peat in cores collected from organic-rich (Jamaica Bay, New York) and mineral (North Inlet, South Carolina) Spartina alterniflora soils. Image analysis software was coupled with the CT images to measure abundance and diameter of the coarse roots and rhizomes in marsh soils. Previously, examination of marsh roots and rhizomes was limited to various hand-sieving methods that were often time-consuming, tedious, and error prone. CT imaging can discern the coarse roots, rhizomes, and peat based on their varying particle densities. Calibration rods composed of materials with standard densities (i.e., air, water, colloidal silica, and glass) were used to operationally define the specific x-ray attenuations of the coarse roots, rhizomes, and peat in the marsh cores. Significant regression relationships were found between the CT-determined wet mass of the coarse roots and rhizomes and the hand-sieved dry mass of the coarse roots and rhizomes in both the organic-rich and mineral marsh soils. There was also a significant relationship between the soil percentage organic matter and the CT-determined peat particle density among organic-rich and mineral soils. In only the mineral soils, there was a significant relationship between the soil percentage organic matter and the CT-determined peat wet mass. Using CT imaging, significant positive nitrogen fertilization effects on the wet masses of the coarse roots, rhizomes, and peat, and the abundance and diameter of rhizomes were measured in the mineral soils. In contrast, a deteriorating salt marsh island in Jamaica Bay had significantly less mass of coarse roots and rhizomes at depth (10-20 cm), and a significantly lower abundance of roots and rhizomes compared with a stable marsh. However, the diameters of the rhizomes in the deteriorating marsh were significantly greater than in the stable marsh. CT imaging is a rapid approach to quantify coarse roots, rhizomes, peat, and soil particle densities in coastal wetlands, but the method is unable at this time to quantify fine roots. PMID:21939051

Davey, Earl; Wigand, Cathleen; Johnson, Roxanne; Sundberg, Karen; Morris, James; Roman, Charles T

2011-09-01

112

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

113

Fate and transport of ambient mercury and applied mercury isotope in terrestrial upland soils: insights from the METAALICUS watershed.  

PubMed

The fate of mercury (Hg) deposited on forested upland soils depends on a wide array of biogeochemical and hydrological processes occurring in the soil landscape. In this study, Hg in soil, soilwater, and streamwater were measured across a forested upland subcatchment of the METAALICUS watershed in northwestern Ontario, Canada, where a stable Hg isotope (spike Hg) was applied to distinguish newly deposited Hg from Hg already resident in the watershed (ambient Hg). In total, we were able to account for 45% of the total mass of spike Hg applied to the subcatchment during the entire loading phase of the experiment, with approximately 22% of the total mass applied now residing in the top 15 cm of the mineral soil layer. Decreasing spike Hg/ambient Hg ratios with depth in the soil and soilwater suggest that spike Hg is less mobile than ambient Hg over shorter time scales. However, the transport of spike Hg into the mineral soil layer is enhanced in depressional areas where water table fluctuation is more extreme. While we expect that this pool of Hg is now effectively sequestered in the mineral horizon, future disturbance of the soil profile could remobilize this stored Hg in runoff. PMID:24383823

Oswald, Claire J; Heyes, Andrew; Branfireun, Brian A

2014-01-21

114

Nitrogen Turnover Processes in Low Temperatures in an Agricultural Peat Soil  

NASA Astrophysics Data System (ADS)

Nitrogen (N) cycling in agricultural soils has a key impact on the environment. Agricultural ecosystems are the most important sources of nitrous oxide (N2O), an important greenhouse gas, to the atmosphere. Additionally N fertilizers used to improve plant growth lead to enhanced N leaching and thereby to eutrophication of surrounding aquatic ecosystems. Microbial processes are normally enhanced by increase in temperature. Several recent studies have shown that although N2O emissions from agricultural soils are of microbiological origin, produced mainly in microbial reduction of nitrate (NO3-) via nitric oxide (NO) and N2O to molecular nitrogen (N2) (denitrification), the temperature response of N2O emissions is greatly variable and there is a lot of evidence of high emissions during cold periods (Koponen et al. 2006). Denitrification is, however, regulated by availability of inorganic N and therefore dependant not only on N fertilization but also on N turnover processes in soil. These processes include mineralization of organic N to ammonium (NH4+), oxidation of NH4+ to nitrite and NO3- (nitrification). These processes and their regulation especially in low temperatures are yet poorly understood. In this experiment, gross rates of N mineralization and nitrification and carbon dioxide production were studied in various temperatures ranging from -1.5 to 15 °C. Soil samples were taken from grassland on peat soil in Southern Finland (60o49’N, 23o30’E) on September 8th 2008 from depths of 0-10 cm. Temperature responses of N gross mineralization and nitrification and of microbial respiration were measured in a laboratory experiment. The incubation temperatures used for experiments were 15, 5, 2.5, 1.5, 0.5, 0, -0.5 and -1.5 °C. After 7 d temperature-specific incubation, gross rates of N mineralization and nitrification were determined with pool dilution technique in a 24 h incubation experiment. This study showed that N turnover processes in agricultural peat soil exhibit temperature anomalies. Carbon dioxide production decreased linearly with decrease in temperature, while gross nitrification and mineralization rates showed high variability in low temperatures and showed no significant differences between studied temperatures. References: Koponen HT , Duran CE, Maljanen M, Hytönen J, Martikainen PJ. 2006. Temperature responses of NO and N2O emissions from boreal organic soil. Soil Biology & Biogeochemistry 38, 1779-1787.

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

2009-12-01

115

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

EPA Science Inventory

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

116

Manipulation of soil microbial community structure in bog and forest soils using chloroform fumigation  

Microsoft Academic Search

Chloroform fumigation was used to manipulate the composition of microbial communities as a means of investigating relationships between community structure and the functioning of soil processes. Soils from two upland sites, a coniferous forest and a peat bog were fumigated with chloroform for 2, 12, 24 or 72 h. Samples were then incubated at 20°C for 4 weeks to investigate

H. E. Dickens; J. M. Anderson

1999-01-01

117

Effects of different chemical modifications on peat humic acid and their bearing on some agrobiological characteristics of soils  

Microsoft Academic Search

Twelve preparations from peat humic acid were obtained through laboratory treatments modifying its structural parameters, oxygen (O)?containing functional groups and nitrogen (N) content. The treatments included acetylation, amidation, ammonia fixation, methylation, nitration, oximation, sulphonation, and selective degradations. The transformed humic products were characterized by routine laboratory analyses. Then, plant yield and different properties of two soils treated with the corresponding

Gonzalo Almendros

1994-01-01

118

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

Technology Transfer Automated Retrieval System (TEKTRAN)

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

119

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...

120

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

Microsoft Academic Search

Arctic peat soils contain vast reserves of organic C and are largely anaerobic. However, anaerobic respiration, particularly the role of Fe(III) and humic substances as electron acceptors, is not well understood in such ecosystems. We investigated these processes in a drained thaw lake basin on the Arctic coastal plain near Barrow, Alaska. We measured concentrations of soluble Fe and other

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

2010-01-01

121

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

122

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

123

Increase of N 2 O Fluxes in Agricultural Peat and Sandy Soil under Elevated CO 2 Concentration: Concomitant Changes in Soil Moisture, Groundwater Table and Biomass Production of Phleum pratense  

Microsoft Academic Search

The effects of elevated atmospheric CO2 concentration on soil moisture, N2O fluxes, and biomass production of Phleum pratense were studied in the laboratory. Farmed peat and sandy soil mesocosms sown with P. pratense were fertilized with a commercial fertilizer. In peat soil 10 g N m?2 of commercial fertilizer were added and in sandy soil 15 g N m?2. In both experiments, soil moisture was regulated with

Riitta Kettunen; Sanna Saarnio; Pertti J. Martikainen; Jouko Silvola

2006-01-01

124

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

NASA Astrophysics Data System (ADS)

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

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

2015-03-01

125

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

126

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

127

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

128

In situ quantification of CH4 bubbling events from a peat soil using a new infrared laser spectrometer Sbastien Gogo Christophe Guimbaud Fatima Laggoun-Dfarge Valry Catoire Claude Robert  

E-print Network

1 In situ quantification of CH4 bubbling events from a peat soil using a new infrared laser in May 2009, in Sphagnum and Betula plots, and in a wet artificially bared peat area with Eriophorum of increased CH4 production and accumulation in peat. In May, bubbling was higher at nighttime (65.5%) than

Paris-Sud XI, Université de

129

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

SciTech Connect

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

Parsekian, Andrew D. [Rutgers University; Slater, Lee [Rutgers University; Ntarlagiannis, Dimitrios [Rutgers University; Nolan, James [Rutgers University; Sebestyen, Stephen D [USDA Forest Service, Grand Rapids, MN; Kolka, Randall K [USDA Forest Service, Grand Rapids, MN; Hanson, Paul J [ORNL

2012-01-01

130

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

PubMed

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

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

2012-07-01

131

Suspending multi-walled carbon nanotubes by humic acids from a peat soil.  

PubMed

Suspension of the pristine and COOH-substituted multi-walled carbon nanotubes (P- and C-MWCNTs) with different outer diameters (ODs) by humic acids (HAs) from a peat soil was examined. Under shaking condition, MWCNTs were not suspended within 5 d. Without HAs, C-MWCNTs were slightly suspended by sonication within 16 h, but no suspension was observed for the pristine ones (P-MWCNTs). HAs greatly enhanced suspension of both P- and C-MWCNTs. The suspension enhancement was attributed to HA sorption, which increased electrostatic repulsion and steric hindrance between individual MWCNTs. Introduction of O-containing hydrophilic moieties to MWCNTs via HA sorption enhanced the interactions of their surfaces with water through H-bonding. Suspending capability of various MWCNTs on suspended mass concentration basis by four HAs showed inconsistent orders with the increasing or decreasing trend of their ODs. However, the suspended surface area concentrations of both P- and C-MWCNTs by individual HAs consistently followed an order of P8 > P30 > P50, and C8 > C30 > C50 (P and C, respectively, refer to P- and C-MWCNTs, and the numbers represent their ODs). These data implied that MWCNTs with smaller OD could be more strongly suspended by a given HA relative to those with larger OD under sonication condition. PMID:22376064

Zhou, Xinzhe; Shu, Liang; Zhao, Huibin; Guo, Xiaoying; Wang, Xilong; Tao, Shu; Xing, Baoshan

2012-04-01

132

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

133

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

134

Ecological Framework For Assessing Changes In Soil Water And Carbon In Response To Degrading Permafrost  

NASA Astrophysics Data System (ADS)

The response of soil water and carbon to permafrost degradation differs greatly across the varied terrain of boreal Alaska. Responses can be broadly partitioned among rocky uplands on ice poor bedrock and colluvial deposits, loamy uplands on extremely ice rich Pleistocene loess, sandy lowlands on sand sheets, and peaty lowlands on abandoned floodplains, retransported deposits on lower slopes, and lowland loess. On rocky uplands, soil carbon and water stocks are low and most carbon and water is lost after fire and subsequent thawing of permafrost. On loamy uplands, much of the soil carbon is lost after fire, but soils remain saturated after thawing of the ice rich intermediate layer. Deeper permafrost is resilient. On sandy lowlands, forest soils have low carbon stocks and water contents, in contrast to the high carbon stocks in perched lakes maintained by permafrost. Thawing of permafrost leads to drying of forest soils and draining of lakes, exposing soil carbon to aerobic conditions for decomposition. Peaty lowlands have thick peat deposits associated with black spruce permafrost plateaus and unfrozen collapse-scar bogs and fens. Thawing leads to 2 to 4 m of collapse and large loss of ice.Formation of bogs impounds water in depressions and leads to rapid accumulation of bog peat. Thawing of forest peat also leads to substantial decomposition of old forest peat.

Jorgenson, T.

2011-12-01

135

Farmers' knowledge of soils in relation to cropping practices: A case study of farmers in upland rice based slash-and-burn  

E-print Network

Farmers' knowledge of soils in relation to cropping practices: A case study of farmers in upland realities of farmer and may be critical for the success or failure of agricultural development. However Keobualapha c , Tatsuhiko Shiraiwa a , Takeshi Horie a a Graduate school of Agriculture, Kyoto University

van Kessel, Chris

136

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...

137

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

138

Glomus mosseae enhances root growth and Cu and Pb acquisition of upland rice (Oryza sativa L.) in contaminated soils.  

PubMed

A pot culture experiment was carried out to investigate the roles of Glomus mosseae in Cu and Pb acquisition by upland rice (Oryza sativa L.) and the interactions between Cu and Pb. The soil was treated with three Cu levels (0, 100 and 200 mg kg(-1)) and three Pb levels (0, 300, and 600 mg kg(-1)). All treatments were designed with (+M) or without (-M) G. mosseae inoculation in a randomized block design. The addition of Cu and Pb significantly decreased root mycorrhizal colonization. Compared with -M, +M significantly increased root biomass in almost all treatments, and also significantly increased shoot biomass in the Pb(0)Cu(200), Pb(300)Cu(0), and all Pb(600) treatments. AM fungi enhanced plant Cu acquisition, but decreased plant Cu concentrations with all Cu plus Pb treatments, except for shoot in the Cu(200)Pb(600) treatment. Irrespective of Cu and Pb levels, +M plants had higher Pb uptakes than -M plants, but had lower root Pb and higher shoot Pb concentrations than those of -M plants. Another interpretation for the higher shoot Pb concentration in +M plants relied on Cu-Pb interactions. The study provided further evidences for the protective effects of AM fungi on upland rice against Cu and Pb contamination, and uncovered the phenomenon that Cu addition could promote Pb uptake and Pb partitioning to shoot. The possible mechanisms by which AM fungi can alleviate the toxicity induced by Cu and Pb are also discussed. PMID:25326862

Lin, Aijun; Zhang, Xuhong; Yang, Xiaojin

2014-12-01

139

Application of a mechanistic desorption-biodegradation model to describe the behavior of polycyclic aromatic hydrocarbons in peat soil aggregates.  

PubMed

A procedure was developed to obtain three size fractions (2360 < d(p) < 1000, 1000 < d(p) < 710, and 710 < d(p) < 425 microm) of stable aggregates from Koopveen peat soil by application of an intense mixing regime prior to sieving of the soil material. The organic matter content, aggregation structure and the microstructure of these aggregates were determined and the particles were artificially contaminated with naphthalene and phenanthrene via a solvent phase. A nonlinear Freundlich sorption isotherm was determined for the naphthalene contaminated soil aggregates (n = 0.39; K(F) = 1.13 x 10(-2) m(1.17) kg(-0.39)). The applicability of a mathematical model, that describes sorption equilibrium, intraparticle mass-transfer, and nonlinear bacterial degradation kinetics, was tested by fitting results of dynamic desorption and biodegradation experiments, generated in this study and earlier work on the peat soil aggregates. The experimental data were described adequately although strong variations in the values of the fit parameter, the intra-particle porosity (0.30 < epsilon < 0.88), were found. This indicates the necessity of further investigations. PMID:11100929

Mulder, H; Breure, A M; Rulkens, W H

2001-01-01

140

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

141

The solid-solution partitioning of heavy metals (Cu, Zn, Cd, Pb) in upland soils of England and Wales.  

PubMed

Ninety-eight surface soils were sampled from the uplands of England and Wales, and analysed for loss-on-ignition (LOI), and total and dissolved base cations, Al, Fe, and trace heavy metals (Cu, Zn, Cd, Pb). The samples covered wide ranges of pH (3.4-8.3) and LOI (9-98%). Soil metal contents measured by extraction with 0.43 mol l-1 HNO3 and 0.1 mol l-1 EDTA were very similar, and generally lower than values obtained by extraction with a mixture of concentrated nitric and perchloric acids. Total heavy metal concentrations in soil solution depend positively upon soil metal content and [DOC], and negatively upon pH and LOI, values of r2 ranging from 0.39 (Cu) to 0.81 (Pb). Stronger correlations (r2=0.76-0.95) were obtained by multiple regression analysis involving free metal ion (Cu2+, Zn2+, Cd2+, Pb2+) concentrations calculated with the equilibrium speciation model WHAM/Model VI. The free metal ion concentrations depend positively upon MHNO3 and negatively upon pH and LOI. The data were also analysed by using WHAM/Model VI to describe solid-solution interactions as well as solution speciation; this involved calibrating each soil sample by adjusting the content of "active" humic matter to match the observed soil pH. The calibrated model provided fair predictions of total heavy metal concentrations in soil solution, and predicted free metal ion concentrations were in reasonable agreement with the values obtained from solution-only speciation calculations. PMID:12810315

Tipping, E; Rieuwerts, J; Pan, G; Ashmore, M R; Lofts, S; Hill, M T R; Farago, M E; Thornton, I

2003-01-01

142

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

Microsoft Academic Search

Little is known about the role of vegetated hillslope sediment transport in the soil C cycle and soil-atmosphere C exchange. We combined a hillslope sediment transport model with empirical soil C measurements to quantify the erosion and temporal storage of soil organic carbon (SOC) within two grasslands in central California. The sites have contrasting erosional mechanisms: biological perturbation (Tennessee Valley

Kyungsoo Yoo; Ronald Amundson; Arjun M. Heimsath; William E. Dietrich

2005-01-01

143

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

144

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

145

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

SciTech Connect

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.

Houser, Jeffrey N [ORNL

2005-01-01

146

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

147

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

NASA Astrophysics Data System (ADS)

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

Shotyk, William

2013-04-01

148

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...

149

The migration of uranium into peat-rich soils at Broubster, Caithness, Scotland, U.K.  

NASA Astrophysics Data System (ADS)

Uranium is being actively transported from uraniferous sedimentary rocks into a peat bog at the Broubster natural analogue site in Caithness, Scotland. Massive calcareous sandstone within the Caithness Flags sequence is the main source of uranium which resides primarily within diagenetic apatite and dispersed U?Si?Ti phases. Supergene weathering processes have decalcified the sandstone and are effective in mobilising uranium by groundwater leaching, primarily along a fault zone. Uranium transport in solution by means of groundwater and surface flows is effectively terminated by retardation within 4-kyr-old peat deposits laid down on boulder clay. This process of secondary fixation has resulted in a young uranium anomaly in the peat which comprises in excess of 0.1 wt% U. The site has been investigated comprehensively to define the geometry of the anomaly together with the hydrogeology, hydrochemistry, petrology, mineralogy and the nature of the peat sink-term. The main physical and geochemical properties of the system, including the uranium decay series radionuclide distributions in water and solid samples, are documented in this paper. From these data, the processes governing the distribution of uranium have been quantified using a three-dimensional groundwater flow package and an equilibrium speciation model incorporating a recently developed electrostatic surface complexation model to account for cation-organic interactions. The results described form part of a coordinated project on natural radionuclide migration undertaken to improve confidence in predictive methods used for radiological assessment.

Read, D.; Bennett, D. G.; Hooker, P. J.; Ivanovich, M.; Longworth, G.; Milodowski, A. E.; Noy, D. J.

1993-06-01

150

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

151

Postglacial variations in distributions, 13C and 14C contents of aliphatic hydrocarbons and bulk organic matter in three types of British acid upland soils  

Microsoft Academic Search

The post-glacial variations in distributions and 13C contents for individual aliphatic hydrocarbons and bulk organic matter down the profiles of three stratified organic upland soils (peaty gley, podzol and acid brown earth) in the U.K. were studied by a combination of conventional radiocarbon dating and accelerator mass spectrometry (AMS) and gas chromatography (GC), gas chromatography-mass spectrometry (GC-MS) and gas chromatography-isotope

Yongsong Huang; Roland Bol; Douglas D. Harkness; Philip Ineson; Geoffrey Eglinton

1996-01-01

152

Acidification of soil-water in low base-saturated sand soils of the superior uplands under acid and normal precipitation.  

PubMed

Lakes and streams are acidified by direct precipitation and water channeled through nearby soils, but water in low base-saturation soils can produce highly acidic percolate after prolonged contact and subsequent degassing in surface waters. Theories advanced by Reuss (1983), Reuss and Johnson (1985), and Seip and Rustad (1984) suggest that soils with less than 15% base saturation are susceptible to soil-water pH depression of up to 0.4 unit, which is sufficient to cause negative alkalinity in soil solutions. High concentrations of mobile anions (notably sulfate) are responsible for the negative alkalinity and these solutions on CO2 degassing in surface waters can retain acidities equivalent to a pH value of 5.0 or less. This mechanism purports to explain why some lakes acidify when they are surrounded by acid soils and cation leaching is not required.Ambient precipitation set to pH 5.4 and pH 4.2 was applied to columns of low base-saturated, sand, soils, starting in 1985. The columns (15 cm diameter and 150 cm long) were collected from soils with base saturations falling into one of three groups (0-10, 10-20, and 20-40%) from national forests in the Superior Uplands area (includes Boundary Waters Canoe Area, Rainbow Lakes, Sylvania, Moquah Barrens, and other Wilderness and Natural areas). The soils were Haplorthods and Udipsamments mainly from outwash plains.The soil columns were instrumented and reburied around a subterranean structure used to collect leachate water and to maintain natural temperature, air, and light conditions. Three humus treatments were applied to soil column (none, northern hardwood, and jack pine) to measure the effect of natural acidification compared to acidification by acid precipitation. The cores were treated with precipitation buffered to pH 5.4 to simulate natural rain and pH 4.2 to simulate acid rain.Columns were treated in 1985 and 1986 with approximately 200 cm of buffered precipitation each year over the frost-free season. Data is now being analyzed for the 1986 treatment year. In leachate collected from the upper horizons of the soil colums, there was a significant difference in pH, alkalinity, nitrate, and sulfate concentrations between the pH 5.4 and pH 4.2 precipitation treatments. This difference, however, disappears at the bottom of the columns. This could be partly due to exchange reactions in the B horizon. The pH and alkalinities are higher in bottom leachate. Chloride and nitrate also increased significantly due mainly to concentrating effects. Even with a pickup of sulfate in the B horizon, sulfate adsorption decreased bottom leachate concentrations well below surface values.Alkalinity, pH, and sulfate concentration in the leachate decreased over the treatment season. Nitrate concentration increased by 4- to 5-fold over the season. Leachate from the bottom of the soil columns is becoming more acidic with time with negative alkalinities appearing more frequently in columns with soils of lower base saturation. There were some significant alkalinity differences due to humus treatments; however, these were not consistent between pH treatments, and need further study. This research will eventually answer whether soil processes can be important to the acidification of lakes in poor, sandy, outwash plains of the Superior Uplands, and whether a reduction in acid sulfate deposition will reverse the percolate alkalinity from negative to positive. PMID:24249061

Harris, A R

1989-04-01

153

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

2003-01-01

154

Peat Characterization and Uptake of Nickel (II) and Cobalt (II) in a Saprist Peat E. S. Asapo1, 2*  

E-print Network

1 Peat Characterization and Uptake of Nickel (II) and Cobalt (II) in a Saprist Peat Column By E. S should be addressed. Email: esasapo@mun.ca Abstract Fibrist and saprist sphagnum peat soils taken from a bog in Torbay, Newfoundland, Canada were characterized. The saprist and fibrist peat soils had wet

Coles, Cynthia

155

Leaching of Solutes from an Intensively Managed Peat Soil to Surface Water  

Microsoft Academic Search

In many peat land areas in The Netherlands target concentrations for nitrogen (N) and phosphorus (P) in surface water are\\u000a exceeded. A considerable, but poorly quantified, fraction, of the N and P loading of surface water in these areas originate\\u000a from the subsoil. Waterboards, responsible for the water management, are currently exploring options to improve surface water\\u000a quality, whilst sustaining

C. L. van Beek; P. Droogers; H. A. van Hardeveld; G. A. P. H. van den Eertwegh; G. L. Velthof; O. Oenema

2007-01-01

156

Methane and carbon dioxide exchange potentials of peat soils in aerobic and anaerobic laboratory incubations  

Microsoft Academic Search

Samples (140) of peat collected from bogs, fens and swamps in boreal, subarctic and temperate regions of Canada were incubated at 15 or 20°C for 5 d in the laboratory to determine potential rates of CO2 and CH4 exchange under aerobic and anaerobic conditions. Rates of CO2 production ranged between 0.07 and 5.0 mg g?1 d?1, with means of 1.0

T. R. Moore; M. Dalva

1997-01-01

157

Bole respiration in a closed-canopy upland oak forest before and after soil moisture manipulations  

SciTech Connect

A throughfall displacement system was established in an upland oak forest stand on Walker Branch Watershed in the fall of 1993. Three 80[times]80 m plots were established adjacent to each other. The system is designed to displace 33% of the throughfall from one plot to another with one ambient plot. Pretreatment and first year post-treatment bole respiration rates were determined at intervals throughout the 1993 and 1994 growing seasons on mature Acer rubrum L., Quercus alba L, and Quercus prinus L. Maintenance and growth respiration data will be presented. Preliminary analysis of the pretreatment data, expressed as CO[sub 2] evolved per unit of cambial surface area, showed positive correlations between tree diameter, sapwood volume, and respiration rates during the [open quotes]dormant[close quotes] season. However, these correlations did not appear during diameter growth, indicating that cambial activity may be the major source of CO[sub 2] efflux from the bole surface during the growing season.

Edwards, N.T.; Hanson, P.J. (Oak Ridge National Laboratory, TN (United States))

1994-06-01

158

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

159

Twenty-Three-Year Changes in Upland and Bottomland Forest Soils of Central Illinois  

E-print Network

protocols. During an 8-year pe- riod in the 1990s, sediment deposition to the floodplain was measured. Soils in the northeastern United States to acidic deposition. Researchers in these studies were able to reach sediment inputs (bottomland soils). These sites were sampled by depth in 1986 and 2009 using the same

David, Mark B.

160

Glasshouse evaluation of the growth of Alnus rubra and Alnus glutinosa on peat and acid brown earth soils when inoculated with four sources of Frankia  

Microsoft Academic Search

The effects of soil type (an acid peat and 2 acid brown earths) andFrankia source (3 spore-positive crushed nodule inocula and spore-negative crushed nodules containing the singleFrankia ArI5) on nodulation, N content and growth ofAlnus glutinosa andA. rubra were determined in a glasshouse pot experiment of two years duration. Plants on all soils required additional P for growth. Growth of

L. J. Sheppard; J. E. Hooker; C. T. Wheeler; R. I. Smith

1988-01-01

161

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

Microsoft Academic Search

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

N. A. Avetov

2009-01-01

162

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

163

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

164

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

165

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

166

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

NASA Astrophysics Data System (ADS)

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

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

2010-05-01

167

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 ?g kg(-1) (dry weight) and the results obtained with the two different methods did not differ significantly (p=0.05). The distillation method with an isotope dilution GC-ICP-MS was shown to be a reliable method for the determination of low MeHg concentrations in unpolluted soil samples. Furthermore, the distillation method is solvent-free and less time-consuming and labor-intensive when compared to the solvent extraction method. PMID:25434268

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

2015-04-01

168

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

NASA Astrophysics Data System (ADS)

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

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

2010-12-01

169

Slope position effects on soil fertility and crop productivity and implications for soil conservation in upland northwest Vietnam  

Microsoft Academic Search

Agriculture is increasingly practised on the very steep slopes of mountainous Vietnam with serious problems of soil erosion and degradation. In five Black Thai villages of Yen Chau and Mai Son district, northwest Vietnam, soil parameters and crop yields of 19 maize (Zea mays L.) and 25 cassava (Manihot esculenta Crantz) fields with 33–91% inclination at upper and lower mid

A. Wezel; N. Steinmüller; J. R. Friederichsen

2002-01-01

170

Scale effect of climate on soil organic carbon in the Uplands of Northeast China  

Microsoft Academic Search

Purpose  Climate factors, considered significant factors in regulating soil organic carbon (SOC), are not equally important at all\\u000a spatial scales. However, the scale which provides the optimal relationship between climate and SOC and how that relationship\\u000a varies at multiple scales are still unclear. Thus, it is crucial to study the relationship between climate factors and SOC\\u000a at multiple scales when attempting

Dan-Dan Wang; Xue-Zheng Shi; Hong-Jie Wang; David C. Weindorf; Dong-Sheng Yu; Wei-Xia Sun; Hong-Yan Ren; Yong-Cun Zhao

2010-01-01

171

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

172

Effects of land-use change and fungicide application on soil respiration in playa wetlands and adjacent uplands of the U.S. High Plains.  

PubMed

With the increased use of fungicides in cultivated regions such as the southern High Plains (SHP), U.S., unintentional runoff and drift as well as direct overspray during aerial application lead to environmental exposures that may influence soil microbial communities and related biogeochemical functioning. Our goal was to examine the effects of two popular fungicides Headline® (pyraclostrobin) and Quilt® (azoxystrobin/propiconazole) on respiration from soil microbial communities in playa wetlands embedded in cropland and native grassland and their adjacent watersheds. We monitored fungicide effects (at levels of 0, .1×, 1× and 10× the label rate) by measuring respiration from plant matter amended soils collected from 6 cropland and 6 grassland playas and uplands. In addition, differences in microbial community structure among land use types were determined by measuring ergosterol levels in cropland and native grassland playas and uplands. Native grassland playas and their associated watersheds had up to 43% higher soil respiration rates than cropland playas and watersheds, indicating higher soil microbial activity. Application of either fungicide had no effect on soil respiration at any concentration in either land use type or habitat type (playa/watershed). Native grassland playas and watersheds had 3 and 1.6 times higher ergosterol content than cropland playas and watersheds. The lack of soil respiration response to fungicide application does not necessarily suggest that fungicides used in this study do not affect non-target soil microbial communities due to potential compensation by other biota. Future studies should further elucidate existing microorganism communities in playas and their watersheds. PMID:25668281

Daniel, Dale W; Smith, Loren M; Belden, Jason B; McMurry, Scott T; Swain, Shella

2015-05-01

173

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

PubMed

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

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

2013-10-01

174

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

PubMed

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

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

2008-12-01

175

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

176

Peat hydraulic conductivity in different landuses  

NASA Astrophysics Data System (ADS)

Information on hydraulic conductivity and water retention properties of peatlands is needed, e.g., for modelling hydrology and soil carbon balance of peat soils. Ability to model the behaviour of peat soils, especially those drained for agricultural use, is important as cultivated peatlands act as a major source of CO2 and N2O emissions in Nordic countries. Peat soil hydraulic conductivity and water retention properties vary greatly, and their relationship to soil depth and degree of decomposition is not straightforward. The aim of this study was to produce new information about peat physical properties in different land uses and the relationship between peat soil hydraulic conductivity and variables such as soil porosity and degree of humification. Peat hydraulic conductivity was measured in situ with infiltrometer (direct push piezometer) in six study sites (two pristine bogs, two sites drained for forestry, a cultivated peat land site and a peat extraction site). Measurements were made in several depths according to soil profile. To examine relationship of soil properties and the hydraulic conductivity, undisturbed peat cores of known volume and also disturbed peat samples were collected from the study sites for determination of von Post humification factor, ash content, porosity and bulk density. Surface layer of the agricultural site had high ash content and bulk density and low porosity compared to the soil beneath it and the soil in other study sites. This was due to added sand and compaction by agricultural practice. Bog, in contrast, had very low bulk density and high porosity. Results show a great variation in hydraulic conductivity within the study sites even when the observations were in the same soil layer. Hydraulic conductivity was lowest in the peat extraction site and the agricultural site, and had higher correlation with study site (= landuse) and the measured layer than with soil porosity.

Mustamo, Pirkko; Hyvärinen, Maarit; Ronkanen, Anna-Kaisa; Kløve, Bjørn

2013-04-01

177

Biodiversity Toolkit Why we DON'T DIG PEAT  

E-print Network

Biodiversity Toolkit Peat free Why we DON'T DIG PEAT The collegiate University is working to help the environment and wildlife by phasing out its use of products containing peat, such as compost and soil improver.admin.ox.ac.uk/estates/environment/biodiversity Cut your carbon emissions Wildlife living in peat bogs includes foxes, Irish hares, pygmy shrews, red

Melham, Tom

178

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

179

Impact of electromagnetic microwaves on the germination of spores of Streptomyces xanthochromogenes in a peat soil and in a liquid nutrient medium  

NASA Astrophysics Data System (ADS)

The impact of microwaves on the germination of spores of Streptomyces xanthochromogenes in a liquid nutrient medium and in a peat soil was studied. The treatment of inoculums with microwave radiation affected the development of the microorganisms from the stage of spore germination to the stage of the formation of microcolonies of actinomycetes upon the spore cultivation in the liquid medium. Typical hypnum-herbaceous peat was used to study the rate of germination of the actinomycetal spores in soil. The study of the dynamics of the Streptomyces xanthochromogenes population in the control soil (without treatment with microwaves) showed that the most active development of the culture took place in the soil moistened to 60% of the maximum water capacity. When the soil was moistened to the minimum adsorption capacity, the streptomyces did not complete their full cycle of development. The stimulation of the spore germination and mycelium growth with microwaves in the soil medium required a longer period in comparison with that for the liquid medium. The stimulation of the spore germination was observed in the liquid nutrient medium in the case of 30-s treatment and in the soil in the case of 60-s treatment.

Komarova, A. S.; Likhacheva, A. A.; Lapygina, E. V.; Maksimova, I. A.; Pozdnyakov, A. I.

2010-01-01

180

Effect of ph on precipitation of humic acid from peat and mineral soils on the distribution of phosphorus forms in humic and fulvic acid fractions  

Microsoft Academic Search

Humic and fulvic acid fractions were isolated from a mineral soil and a peat by adjusting the pH of the alkali extracts to a range of values from 0.2 to 2.5. Total inorganic and organic forms of phosphorus (P) in the acids were measured by chemical analysis and by P NMR spectroscopy. As the pH of precipitation of the mineral

C. N. Bedrock; M. V. Cheshire; J. A. Chudek; A. R. Fraser; B. A. Goodman; C. A. Shand

1995-01-01

181

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

182

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

NASA Astrophysics Data System (ADS)

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

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

183

Thermal properties of peat, marshy and mineral soils in relation to soil moisture status in Polesie and Biebrza wetlands  

NASA Astrophysics Data System (ADS)

Knowledge of thermal properties of soil helps in estimating heat fluxes as an important component of the heat balance. The research was conducted to evaluate spatial distribution of the soil thermal properties (thermal conductivity, heat capacity and thermal diffusivity) in relation to soil wetness and bulk density in wetland soils of Polesie and Biebrza regions (Poland). Soil moisture content and bulk density together with soil temperature and texture data, were used for determination of thermal properties. The thermal conductivity was measured, by KD2 Pro Decagon, and calculated by the physical-statistical model of Usowicz, and the heat capacity - was calculated with empirical formulae, and the thermal diffusivity was determined by the ratio of thermal conductivity to the heat capacity. The thermal conductivity of wetland and marsh soils increases with increasing moisture content and density of the soil to higher extent in soils richer in minerals - mostly quartz. Maximum thermal conductivity of the wetland soils at different density did not exceed the value of the thermal conductivity of water. However, for mineral soil at the natural density (1.31 Mg m-3) and with the quartz content of 96%, the thermal conductivity is about four times greater than the thermal conductivity of water. This is due to that the thermal conductivity of quartz is sixteen times greater than that of water. Dependence of the soil thermal conductivity on moisture content is non-linear and the shape of the non-linearity largely depends on the density of the soil. Particular components of soil bring their contribution to the conductivity respectively to their fractions and compounds being dominant in the ground contribute mostly to the effective slope of the thermal conductivity versus the water content at a given soil density. The heat capacity of the soil substrate is linearly dependent on the water content. Soils containing more organic matter within low specific densities, usually are characterized by less or minimal available heat capacity values in dry conditions, while they can also be characterized by highest or maximal heat capacity values, in highly wet conditions approaching the saturation with water. The increase in soil density caused a parallel shift of the characteristics of the heat capacity in the direction of higher values. This was associated with an increase in solids content per unit volume of the substrate and the reduction of the water content and the specific heat capacity of the individual components of the soil. Thermal diffusivity of soils exhibits characteristic extremes. In organic soils characteristic minimal or maximal extremes may occur, while mineral soils achieve only maximal diffusivity values on regular basis. Extremes of the thermal diffusivity are mainly due to the changes in the intensity of the thermal conductivity of the substrate due to change in soil moisture content and density. The heat capacity of the soil increases with increasing moisture content at the constant rate. The value of soil thermal diffusivity depends highly on quartz content. Thermal diffusivity of the soil with the same moisture content was greater for the higher densities, and minimum or maximum thermal diffusivity tends to move toward the lower moisture content for higher densities. The observed extremes are so distinctive that they determine the value of soil moisture and density, at which the temperature wave travels the slowest and the fastest in the soil. The question of determining and sensing the water capacity is also affected by the texture and porosity. Simple volumetric measures of porosity are used, but with distinguishing the volume of pores filled by air and other part filled with water. Practically, porosity is treated simply and is included to assessments by effects on the thermal properties. We prove that thermal properties are very good variables for a sensitive indicator of the water content, and accounting the impact from porosity. Thermal properties gather effects from the texture and porosity cumulatively. Therefo

Usowicz, Boguslaw; ?ukowski, Mateusz; Marczewski, Wojciech; Usowicz, Jerzy B.; Lipiec, Jerzy; Stankiewicz, Krystyna

2013-04-01

184

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

USGS Publications Warehouse

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

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

2013-01-01

185

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

186

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

USGS Publications Warehouse

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

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

2008-01-01

187

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

NASA Astrophysics Data System (ADS)

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

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

2013-05-01

188

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

SciTech Connect

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

Kapustka, L.A. [Ecological Planning and Toxicology, Inc., Corvallis, OR (United States); Lipton, J.; Galbraith, H.; Cacela, D.; LeJeune, K. [Hagler Bailly Consulting, Inc., Boulder, CO (United States)

1995-11-01

189

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

190

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

Microsoft Academic Search

Changes in the trophic status and moistening of oligotrophic peat soils subjected to oil pollution and subsequent reclamation\\u000a in the middle reaches of the Ob River are discussed. The main plants-indicators are listed. Numerical estimates of the trophic\\u000a level and the degree of moistening of natural and transformed soils of the widespread bog biogeocenoses—pine-dwarf-shrub-sphagnum,\\u000a complex ridged-hollow, and cotton grass-sphagnum bogs—are

N. A. Avetov

2009-01-01

191

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

PubMed

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

Sawada, Kozue; Toyota, Koki

2015-03-24

192

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

PubMed Central

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

Sawada, Kozue; Toyota, Koki

2015-01-01

193

Methane Emissions from Upland Trees  

NASA Astrophysics Data System (ADS)

Most work on methane (CH4) emissions from natural ecosystems has focused on wetlands and wetland soils because they are predictable emitters and relatively simple to quantify. Less attention has been directed toward upland ecosystems that cover far larger areas, but are assumed to be too dry to emit CH4. There is abundant evidence that upland ecosystems emit small amounts of CH4 during hot moments that collectively constitute a significant source in the global budget of this potent greenhouse gas. We have established two transects across natural moisture gradients in two forests near Annapolis, Maryland. Both tree and soil methane fluxes were measured using chamber methods. Each tree chamber was custom fit to the stem near the base. In addition, porewater methane concentrations were collected at multiple depths near trees. Abiotic parameters such as soil temperature, soil moisture, water potential, and depth to groundwater were monitored using a wireless sensor network. Upland emissions from tree stems were as high as 14.6 umoles CH4 m-2 hr-1 while the soil uptake was -1.5 umoles CH4 m-2 hr-1. These results demonstrate that tree methane emissions and soil methane uptake can occur simultaneously in a mesic forest. Factors controlling methane emissions were soil temperature, soil moisture, and depth to groundwater. Based on our preliminary data, tree mediated methane emissions may be offsetting the soil methane sink of upland forests by 20 to 30%. Future methane budgets and climate models will need to include tree fluxes and the parameters that control methane emissions for accurate accounting and predictions.

Pitz, S.; Megonigal, P.; Schile, L. M.; Szlavecz, K. A.; King, K.

2013-12-01

194

Internal eutrophication in peat soils through competition between chloride and sulphate with phosphate for binding sites  

Microsoft Academic Search

Inputs of surface waters high in chloride and sulphateincreased the availability of nutrients in fenpeatlands. This `internal eutrophication' wasdemonstrated with test plants (`phytometers') andthrough water and soil analysis. Three experiments arepresented in which the level of chloride and\\/orsulphate was increased to 3 mmolc l-1. Inexperiment 1 chloride levels were increased from 0.5to 3 mmolc l-1 as CaCl2 or NaCl. Inexperiment

B. Beltman; T. G. Rouwenhorst; M. B. Van Kerkhoven; T. Van Der Krift; J. T. A. Verhoeven

2000-01-01

195

Metagenomic Insights into Anaerobic Metabolism along an Arctic Peat Soil Profile  

PubMed Central

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

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

2013-01-01

196

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

NASA Astrophysics Data System (ADS)

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

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

2013-12-01

197

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

NASA Astrophysics Data System (ADS)

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

Karki, S.; Elsgaard, L.; Lærke, P. E.

2015-01-01

198

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

NASA Astrophysics Data System (ADS)

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

Karki, S.; Elsgaard, L.; Lærke, P. E.

2014-09-01

199

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

200

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

201

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

202

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...

203

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

204

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

205

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

206

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

NASA Astrophysics Data System (ADS)

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

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

2014-11-01

207

Climatic influences on the leaching of dissolved organic matter from upland UK moorland soils, investigated by a field manipulation experiment  

Microsoft Academic Search

The leaching of dissolved organic matter (DOM) from three acidic soils (brown earth, micropodzol, and peaty gley), under different climatic conditions, was investigated. Cores of undisturbed soil, taken from near the summit of Great Dun Fell (Cumbria, U.K.), were maintained at the summit (site A), and at three lower-altitude sites (B, C, and D) with higher mean temperatures and lower

D. D. Harkness; C WOOF; E RIGG; A HARRISON; P INESON; K TAYLOR; D BENHAM; J POSKITT; A ROWLAND; R BOL

1999-01-01

208

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

209

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

210

The Future of Carbon Storage in Upland Blanket - the Case of the English Peak District  

NASA Astrophysics Data System (ADS)

This study applies a model of carbon uptake and release pathways across managed and damaged upland peats at a regional scale (725 km2). The aim is to understand the present and future carbon and equivalent CO2 storage of the peat soils under different management and warming scenarios, relative to the current budget. The model applies a series of possible management changes - cease prescribed burning, cease grazing, restore peat surface, block soil drains and an optimal combination of management. The management scenarios are judged under a climate warming scenario by extrapolation of current patterns and trends to 2030. 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. In response to current climate trends in northern England, this paper shows that the current rate of decline in equivalent CO2 storage is 3.7 tonnes CO2 eq. km-2 yr-2 or 146 tonnes CO2 eq. km-2 yr-2 per oC. The region would become a net source of equivalent CO2 by 2033, but if optimal land management for CO2 protection was undertaken now the transition to a net source would be delayed until 2086. The study suggests that without any change in land management, the region is only capable of absorbing a temperature change of less than 1oC, but with optimal land management carbon stores in blanket peatlands at the study site could be retained at temperature increases of up to 2oC.

Dixon, S.; Worrall, F.

2010-12-01

211

Heavy metals deposited from the atmosphere on upland Scottish soils: Chemical and lead isotope studies of the association of metals with soil components  

NASA Astrophysics Data System (ADS)

Three soil profiles taken from the Hartwood Research Station in Central Scotland have been analyzed using chemical digestion and extraction techniques to investigate the chemical association of heavy metals deposited from the atmosphere. Total digestion, EDTA extraction and the BCR (Bureau Communitaire de Reference) sequential extraction procedure were used. In addition, lead isotope ratios in the whole soils and in the fractions from the sequential extraction procedure were measured using thermal ionisation mass spectrometry. All the digestion and extraction procedures gave clear indication of enhanced concentrations of heavy metals in surface soils, in particular for lead and zinc. Whereas total digestion gave a good indication of the heavy metal status of the soils, the extraction procedures were necessary to provide information on chemical association of the metals with soil components, information needed to understand the soil processes involved in mobilization of metals. Lead isotope analysis of the whole soils revealed a consistent picture of lower 206Pb/ 207Pb ratios in surface soils (1.140-1.147) than in soils at 20-30 cm depth (1.182-1.190). The steady progression from the lower to higher ratios down the profile was clear indication that anthropogenic lead had penetrated to some degree into the deeper soils. The combination of sequential extraction and lead isotope analysis proved to be a powerful approach to studying this effect in more detail and showed that the fractions extractable from 20 to 30 cm soils contained lead with much lower 206Pb/ 207Pb ratios (1.174-1.178) than the residual fraction (1.196-1.200). As the extractable fractions contained ?85% of the lead in the soil, a substantial portion of lead at 20-30 cm depth was of anthropogenic origin. The 206Pb/ 207Pb ratios of 1.174-1.178 found in the extractable fractions suggested that the mobile component of the anthropogenic lead was that deposited before the introduction of leaded petrol.

Bacon, Jeffrey R.; Hewitt, Irene J.

2005-01-01

212

2008 Macmillan Publishers Limited. All rights reserved. 2008 Macmillan Publishers Limited. All rights reserved. High sensitivity of peat decomposition  

E-print Network

rights reserved. LETTERS High sensitivity of peat decomposition to climate change through water of the high water-holding capacity of peat and its low hydraulic conductivity, accumulation of soil organic­biogeochemical soil model with peat depths that are continuously updated from the dynamic balance of soil organic

Moorcroft, Paul R.

213

[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

214

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

215

Heavy metals deposited from the atmosphere on upland Scottish soils: Chemical and lead isotope studies of the association of metals with soil components  

Microsoft Academic Search

Three soil profiles taken from the Hartwood Research Station in Central Scotland have been analyzed using chemical digestion and extraction techniques to investigate the chemical association of heavy metals deposited from the atmosphere. Total digestion, EDTA extraction and the BCR (Bureau Communitaire de Reference) sequential extraction procedure were used. In addition, lead isotope ratios in the whole soils and in

Jeffrey R. Bacon; Irene J. Hewitt

2005-01-01

216

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

217

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

218

Dynamic response of Mercer Slough peat  

SciTech Connect

The behavior of a peat from Mercer Slough in Bellevue, Wash., was investigated by a program of field and laboratory testing. The peat was very soft, very weak, and highly compressible. Water contents averaged approximately 600% and in situ shear wave velocities were measured at 12--30 m/s. Cyclic triaxial and resonant column testing indicated that the modulus reduction and damping behavior of Mercer Slouth peat was significantly influenced by strain amplitude and effective confining pressure and was weakly influenced by loading frequency and overconsolidation ratio. Comparison of the behavior of Mercer Slough peat with other highly organic soils suggests a trend of increasing linearity and decreasing damping with increasing effective confining pressure. Site response analyses indicated strong response at low frequencies with spectral shapes that differ significantly from the standard shapes implied by current codes.

Kramer, S.L.

2000-06-01

219

A cellular model of Holocene upland river basin and alluvial fan evolution  

Microsoft Academic Search

The CAESAR (Cellular Automaton Evolutionary Slope And River) model is used to simulate the Holocene development of a small upland catchment (4Ð 2k m 2? and the alluvial fan at its base. The model operates at a 3 m grid scale and simulates every flood over the last 9200 years, using a rainfall record reconstructed from peat bog wetness indices

T. J. Coulthard; M. G. Macklin; M. J. Kirkby

2002-01-01

220

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

221

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

222

Carbon budget of drained peat bogs in Ukrainian Polesie  

NASA Astrophysics Data System (ADS)

Methodological aspects of studying the organic carbon budget of drained peat bogs used in agriculture are discussed. Difficulties in the assessment of carbon budget on the basis of measured carbon inflows and outflows are shown. The "soil pool" model of the carbon budget is suggested. It is based on the results of long-term experimental studies of a drained peatland in Ukrainian Polesie. An algorithm for calculating the carbon budget in the aerated part of the peatland—the peat soil proper—is developed with due account for a gradual involvement of the deep peat layers into the zone of soil processes. Data on the loss of dry peat mass and organic carbon per in the course of peat mineralization and surface subsidence are given with due account for the nature of the peatland and the duration of its agricultural use.

Truskavetskii, R. S.

2014-07-01

223

Genetic variation in root morphology and microsatellite DNA loci in upland rice (Oryza sativa L.) from Vietnam  

Microsoft Academic Search

Drought is a major constraint to the productivity of rice in upland ecosystems. The rice root system plays an important role in the regulation of water uptake and extraction from deep soil layers. The aim of this research was to study the variation in root morphology and the genetic diversity in upland rice accessions. Thirty-three upland rice accessions originated from

N. D. Thanh; H. G. Zheng; N. V. Dong; L. N. Trinh; M. L. Ali; H. T. Nguyen

1999-01-01

224

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

225

Changes in the relationship between soil erosion and N loss pathways after establishing soil conservation systems in uplands of Northeast Thailand  

Microsoft Academic Search

Slow establishment of green barriers together with competition for nutrients and water between crops and contour hedges hamper their acceptance by rural communities in tropical mountainous regions. Alternatively, a combination of hedges\\/barriers and minimum tillage may shift the pathway of N losses from water erosion towards leaching. In Northeast Thailand, run-off, soil loss, N leaching (by resin cores) and crop

W. Pansak; T. H. Hilger; G. Dercon; T. Kongkaew; G. Cadisch

2008-01-01

226

Review of pre-treated peat applied in treating domestic wastewaters and oily waters  

Microsoft Academic Search

Peat is commonly used as a combustible fuel for energy and as an addictive to soil in horticulture. For hundreds of years, peat was widely used as a green energy source for heating in the northern parts of Europe and North America. Nowadays, people tend to lay decomposed peat on lawns or gardens as a top layer because of its

Xiao Jiang; Cynthia A. Coles; Emmanuel S. Asapo

2008-01-01

227

Batch and Kinetic Studies of ni adsorption on Highly Humified newfoundland Peat  

E-print Network

Batch and Kinetic Studies of ni adsorption on Highly Humified newfoundland Peat emmanuel s. As's, NL, A1B 3X5, Canada abstract This study employed batch tests with a saprist peat soil from was used to determine the kinetic parameters at solution pH of 5.5 for peat doses of 4, 10, 21 and 40 g

Coles, Cynthia

228

Palynological Analysis of a Peat Core from Imnavait Creek, the North Slope, Alaska  

Microsoft Academic Search

The pollen record of a 160 cm peat core from Imnavait Creek, a small upland basin in the northern foothills of the Brooks Range, Alaska, reveals a history of vegetation change from the early Holocene to the present. The Alnus rise within the region occurred after 8500 yr B.P. Betula and Cypemeae a~ the major floristic elements throughout the diagram,

WENDY R. EISNER

229

Chlorinated hydrocarbons in peat  

SciTech Connect

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

Rapaport, R.A.

1985-01-01

230

Effects of moisture limitation on tree growth in upland and floodplain forest ecosystems in interior Alaska  

Microsoft Academic Search

The objective of this study was to examine the impact of summer throughfall on the growth of trees, at upland and floodplain locations, in the vicinity of Fairbanks, Alaska. Corrugated clear plastic covers were installed under the canopy of floodplain balsam poplar\\/white spruce stands and upland hardwood\\/white spruce stands to control soil moisture recharge as a result of summer precipitation.

John Yarie

2008-01-01

231

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

232

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

233

Short period of oxygenation releases latch on peat decomposition.  

PubMed

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

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

2014-05-15

234

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

235

Dynamic properties of Sherman Island peat  

SciTech Connect

The dynamic properties of peat have been identified as a major source of uncertainty in the evaluation of seismic hazards throughout the Sacramento-San Joaquin Delta in northern California. This paper summarizes the results of a laboratory study of the dynamic properties of a layer of peaty organic soil underlying the south levee on Sherman Island near the western side of the delta. Conventional Shelby tube sampling procedures were able to obtain high-quality samples because of the compactness of this peat layer, located between depths of 9 and 16 m. The samples tested were very fibrous and had ash contents of 35--56%. Staged cyclic triaxial loading was used to measure the stress-strain behavior of several specimens under cyclic shear strains ranging from about 0.0005% to 10%. Other tests included piezo-ceramic bender element tests to measure the shear wave velocity of specimens within the triaxial device, and undrained monotonic triaxial compression and extension tests. The effects of loading frequency, cyclic degradation, consolidation stress history, and structural anisotropy are evaluated. The resulting modulus reduction and damping relationships for the Sherman Island peat are compared with published results for other peats, solid waste materials, and mineral soils.

Boulanger, R.W.; Arulnathan, R. [Univ. of California, Davis, CA (United States). Dept. of Civil and Environmental Engineering; Harder, L.F. Jr.; Torres, R.A.; Driller, M.W. [California Dept. of Water Resources, Sacramento, CA (United States)

1998-01-01

236

Predicting soil respiration from peatlands.  

PubMed

This study considers the relative performance of six different models to predict soil respiration from upland peat. Predicting soil respiration is important for global carbon budgets and gap filling measured data from eddy covariance and closed chamber measurements. Further to models previously published new models are presented using two sub-soil zones and season. Models are tested using data from the Bleaklow plateau, southern Pennines, UK. Presented literature models include ANOVA using logged environmental data, the Arrhenius equation, modified versions of the Arrhenius equation to include soil respiration activation energy and water table depth. New models are proposed including the introduction of two soil zones in the peat profile, and season. The first new model proposes a zone of high CO(2) productivity related to increased soil microbial CO(2) production due to the supply of labile carbon from plant root exudates and root respiration. The second zone is a deeper zone where CO(2) production is lower with less labile carbon. A final model allows the zone of high CO(2) production to become dormant during winter months when plants will senesce and will vary depending upon vegetation type within a fixed location. The final model accounted for, on average, 31.9% of variance in net ecosystem respiration within 11 different restoration sites whilst, using the same data set, the best fitting literature equation only accounted for 18.7% of the total variance. Our results demonstrate that soil respiration models can be improved by explicitly accounting for seasonality and the vertically stratified nature of soil processes. These improved models provide an enhanced basis for calculating the peatland carbon budgets which are essential in understanding the role of peatlands in the global C cycle. PMID:23178842

Rowson, J G; Worrall, F; Evans, M G; Dixon, S D

2013-01-01

237

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

238

Third technical contractors' conference on peat  

SciTech Connect

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

Not Available

1981-01-01

239

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

240

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

NASA Astrophysics Data System (ADS)

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.

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

2015-02-01

241

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

242

Fourth technical contractors' conference on peat  

SciTech Connect

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

Not Available

1981-01-01

243

Fluvial entrainment of low density peat blocks (block carbon)  

NASA Astrophysics Data System (ADS)

In many fluvial environments low density materials are transported in significant quantities and these form an important part of the stream load and /or have a distinct impact on sedimentation in these environments. However, there are significant gaps in understanding of how these materials are entrained and transported by streams and rivers. Eroding upland peatland environments in particular, frequently have fluvial systems in which large eroded peat blocks, often exceeding 1 m in length; form an important component of the stream material flux. Transport of this material is significant in determining rates of erosion but also has important impacts in terms of damage to infrastructure and carbon loss. This paper describes a field experiment designed to establish for the first time the conditions under which large peat blocks (c. > 0.1 m b axis) are initially entrained from a rough gravel bed. The field site is Trout Beck, in the North Pennines, Northern England which is an upland wandering river channel with occasional lateral and mid channel bars. Mean low flow stage is typically 0.2 m but during flood can rapidly rise, in one to two hours, to over 1.5 m. To study peat block entrainment a bespoke data acquisition system consisting of two pressure transducers, four release triggers and time lapse camera was set up. The pressure transducers provided a record of local depth and the release triggers were embedded in peat blocks to record initial motion and arranged on the rough stream bed. The time lapse camera provided verification of timing of block entrainment (during daylight hours) and also provided information on the mechanism of initial movement. Peat blocks were cut from a local source and were equidimensional, ranging in size from 0.1 to 0.7 m. The derived entrainment function is related to a critical depth of entrainment. Results demonstrate that peat blocks are entrained when the local depth approximates the height of the peat block. Blocks frequently shift position prior to entrainment but once entrained are rapidly transported downstream. Because of the rough stream bed local depth, measured on the four sides of the block varies markedly and needs to be considered in developing an appropriate entrainment function and; is useful in explaining initial movement prior to entrainment. In some experiments a small accelerometer (HOBO Pendant G data logger) was used to investigate transport dynamics following entrainment. Further work will seek to improve the entrainment function by extending the size range of tests, developing a shear stress related function and investigating the importance of block shape (rounding) on entrainment.

Warburton, Jeff

2014-05-01

244

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

NASA Astrophysics Data System (ADS)

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

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

2013-04-01

245

Reproducibility of the BCR sequential extraction procedure in a long-term study of the association of heavy metals with soil components in an upland catchment in Scotland  

Microsoft Academic Search

Humic iron podzol soils from three different plots at the Glensaugh Research Station, Aberdeenshire have been sampled on an annual basis since 1990 and analysed using both total digestion and the original BCR sequential extraction procedure. Particular care was required during the oxidation of these organic soils to prevent loss of material. The residue from the sequential extraction was analysed

Jeffrey R. Bacon; Irene J. Hewitt; Patricia Cooper

2005-01-01

246

Cation exchange capacity of pine bark and peat substrates  

Technology Transfer Automated Retrieval System (TEKTRAN)

Cation exchange capacity (CEC) describes the maximum quantity of cations a soil or substrate can hold while being exchangeable with the soil solution. While CEC has been studied for peat-based substrates, relatively little work has documented factors that affect CEC of pine bark substrates. The ob...

247

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

248

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

249

Soil dissolved organic matter export to coastal temperate rainforest streams  

NASA Astrophysics Data System (ADS)

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

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

2006-12-01

250

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

251

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

252

Effects of 4-amino 1,2,4-triazole, dicyandiamide and encapsulated calcium carbide on nitrification inhibition in a subtropical soil under upland and flooded conditions  

Microsoft Academic Search

Nitrification inhibition of soil and applied fertilizer N is desirable as the accumulation of nitrates in soils in excess\\u000a of plant needs leads to enhanced N losses and reduced fertilizer N-use efficiency. In a growth chamber experiment, we studied\\u000a the effects of two commercial nitrification inhibitors (NIs), 4-amino 1,2,4-triazole (ATC) and dicyandiamide (DCD), and a\\u000a commonly available and economical material,

M. S. Aulakh; Kuldip-Singh; J. Doran

2001-01-01

253

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

254

Alfred P. Dachnowski and the scientific study of peats  

USGS Publications Warehouse

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

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

2011-01-01

255

Micro-Scale Distribution and Speciation of Arsenic in Peat  

NASA Astrophysics Data System (ADS)

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

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

2013-04-01

256

Strength Matters: Resisting Erosion Across Upland Landscapes  

NASA Astrophysics Data System (ADS)

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

Heimsath, A. M.

2012-12-01

257

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

Technology Transfer Automated Retrieval System (TEKTRAN)

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

258

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

259

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

EPA Science Inventory

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

260

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

261

The Limits to Peat Bog Growth  

Microsoft Academic Search

Not less than 2% of the Earth's land surface is peat-covered, so it is important to try to understand the dynamics of peat accumulation. Peat-forming systems (mires) accumulate peat because conditions within them impede the decay of the plant material produced by their surface vegetation. This paper concerns the rate of peat production and some unexpected consequences of the processes

R. S. Clymo

1984-01-01

262

Utilization of peat as a fuel  

Microsoft Academic Search

This work has dealt primarily with the development and evaluation of peat\\/No. 2 fuel oil mixtures (POM) and peat\\/methanol mixtures (PAM). POM and PAM slurries with varied peat loadings, peat moisture contents, and peat particle sizes have been studied by measuring slurry sedimentation ratios in jacketed glass tubes and slurry drain times from the tubes along with the slurry viscosities.

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

1981-01-01

263

Processes and mechanisms controlling consumption of CFC11 and CFC12 by peat from a conifer-swamp and black spruce-tamarack bog in New York State  

Microsoft Academic Search

We evaluated the potential consumption of chlorofluorocarbons CFC-11 and CFC-12 by peat soil from a conifer swamp and a temperate bog in New York State in order to assess whether extensive northern peatlands might serve as a sink for atmospheric CFCs. Intact peat cores maintained with an anoxic headspace over the peat surface consumed CFC-11 and minor amounts of CFC-12.

M. R. Bauer; J. B. Yavitt

1996-01-01

264

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

265

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

266

Nutrient availability and response of sago palm (Metroxylon sago Rottb.) to controlled release N fertilizer on coastal lowland peat in the tropics  

Microsoft Academic Search

Sago palms (Metroxylon sagu Rottb.) growing on peat soils were found to grow more slowly and to show a lower production than palms growing on mineral soils. This difference was related to the physical and chemical constraints of peat soils, which include low bulk density, high acidity, and low N, P, K, Ca, Zn, and Cu levels. In coastal lowland

Benito Heru Purwanto; Ken-ichi Kakuda; Ho Ando; Jong Foh Shoon; Yoshinori Yamamoto; Akira Watanabe; Tetsushi Yoshida

2002-01-01

267

7 CFR 1205.13 - Upland cotton.  

Code of Federal Regulations, 2010 CFR

...2010-01-01 2010-01-01 false Upland cotton. 1205.13 Section 1205.13 Agriculture...COMMODITIES), DEPARTMENT OF AGRICULTURE COTTON RESEARCH AND PROMOTION Procedures for...Period Definitions § 1205.13 Upland cotton. The term Upland cotton means...

2010-01-01

268

7 CFR 1205.13 - Upland cotton.  

Code of Federal Regulations, 2012 CFR

...2012-01-01 2012-01-01 false Upland cotton. 1205.13 Section 1205.13 Agriculture...COMMODITIES), DEPARTMENT OF AGRICULTURE COTTON RESEARCH AND PROMOTION Procedures for...Period Definitions § 1205.13 Upland cotton. The term Upland cotton means...

2012-01-01

269

7 CFR 1205.13 - Upland cotton.  

Code of Federal Regulations, 2013 CFR

...2013-01-01 2013-01-01 false Upland cotton. 1205.13 Section 1205.13 Agriculture...COMMODITIES), DEPARTMENT OF AGRICULTURE COTTON RESEARCH AND PROMOTION Procedures for...Period Definitions § 1205.13 Upland cotton. The term Upland cotton means...

2013-01-01

270

7 CFR 1205.13 - Upland cotton.  

Code of Federal Regulations, 2011 CFR

...2011-01-01 2011-01-01 false Upland cotton. 1205.13 Section 1205.13 Agriculture...COMMODITIES), DEPARTMENT OF AGRICULTURE COTTON RESEARCH AND PROMOTION Procedures for...Period Definitions § 1205.13 Upland cotton. The term Upland cotton means...

2011-01-01

271

7 CFR 1205.13 - Upland cotton.  

Code of Federal Regulations, 2014 CFR

...2014-01-01 2014-01-01 false Upland cotton. 1205.13 Section 1205.13 Agriculture...COMMODITIES), DEPARTMENT OF AGRICULTURE COTTON RESEARCH AND PROMOTION Procedures for...Period Definitions § 1205.13 Upland cotton. The term Upland cotton means...

2014-01-01

272

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

273

Climate sensitivity and macronutrient regulation of peat decomposition  

NASA Astrophysics Data System (ADS)

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

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

2013-04-01

274

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

275

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

276

Modeling Northern Peatland Decomposition and Peat  

E-print Network

Modeling Northern Peatland Decomposition and Peat Accumulation Steve Frolking,1 * Nigel T. Roulet,2´al, Quebec, H3C 3J7, Canada ABSTRACT To test the hypothesis that long-term peat accumula- tion is related to contemporary carbon flux dynamics, we present the Peat Decomposition Model (PDM), a new model of long-term peat

Moore, Tim

277

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

278

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

NASA Astrophysics Data System (ADS)

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

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

2010-12-01

279

Runoff generation and water table fluctuations in blanket peat: evidence from UK data spanning the dry summer of 1995  

Microsoft Academic Search

Understanding of the hydrology of upland blanket peatlands has been limited both by the logistical difficulties of obtaining data from such environments and by technical difficulties with plot scale investigations of peat hydrology. The relative importance of infiltration-excess and percolation-excess as runoff generating mechanisms as opposed to the saturation-excess mechanism remains unclear. This study uses catchment-scale runoff data, in combination

M. G. Evans; T. P. Burt; J. Holden; J. K. Adamson

1999-01-01

280

7 CFR 319.69-5 - Types of soil authorized for packing.  

Code of Federal Regulations, 2013 CFR

...Materials Rules and Regulations § 319.69-5 Types of soil authorized for packing. The following types of soil or earth are authorized as safe for packing: (a) Peat, (b) peat moss, and (c) Osmunda...

2013-01-01

281

7 CFR 319.69-5 - Types of soil authorized for packing.  

Code of Federal Regulations, 2011 CFR

...Materials Rules and Regulations § 319.69-5 Types of soil authorized for packing. The following types of soil or earth are authorized as safe for packing: (a) Peat, (b) peat moss, and (c) Osmunda...

2011-01-01

282

7 CFR 319.69-5 - Types of soil authorized for packing.  

Code of Federal Regulations, 2012 CFR

...Materials Rules and Regulations § 319.69-5 Types of soil authorized for packing. The following types of soil or earth are authorized as safe for packing: (a) Peat, (b) peat moss, and (c) Osmunda...

2012-01-01

283

7 CFR 319.69-5 - Types of soil authorized for packing.  

Code of Federal Regulations, 2014 CFR

...Materials Rules and Regulations § 319.69-5 Types of soil authorized for packing. The following types of soil or earth are authorized as safe for packing: (a) Peat, (b) peat moss, and (c) Osmunda...

2014-01-01

284

Understanding fine sediment and phosphorous delivery in upland catchments  

NASA Astrophysics Data System (ADS)

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

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

2013-12-01

285

Peat as an energy alternative  

SciTech Connect

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

Punwani, D.V.

1980-07-01

286

Dewatering Peat With Activated Carbon  

NASA Technical Reports Server (NTRS)

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

Rohatgi, N. K.

1984-01-01

287

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

288

Gas bubble transport and emissions for shallow peat from a northern peatland: The role of pressure changes and peat structure  

NASA Astrophysics Data System (ADS)

Gas bubbles are an important pathway for methane release from peatlands. The mechanisms controlling gas bubble transport and emissions in peat remain uncertain. The effects of hydrostatic pressure and peat structure on the dynamics of gas bubbles in shallow peat were therefore tested in laboratory experiments. A peat monolith was retrieved from a raised bog and maintained in a saturated state. Three distinct layers were identified from noninvasive permittivity measurements supported by soil physical properties (porosity, bulk density). Phase I of the experiment involved monitoring for the accumulation of gas bubbles under steady pressure and temperature conditions. The data showed evidence for gas bubbles being impeded by a shallow semiconfining layer at depths between 10 and 15 cm. Visible gas bubbles observed on the side of the sample box were recorded over time to estimate changes in the vertical distribution of volumetric gas content. Porosity estimates derived using the Complex Refraction Index Model (CRIM) suggest that gas bubbles enlarge the pore space when the exerted pressure is high enough. Phase II involved triggering release of trapped bubbles by repeatedly increasing and decreasing hydrostatic pressure in an oversaturated condition. Comparison of changes in pressure head and methane density in the head space confirmed that the increasing buoyancy force during drops in pressure is more important for triggering ebullition than increasing mobility during increases in pressure. Our findings demonstrate the importance of changes in hydrostatic pressure on bubble size and variations in resistance of the peat fabric in regulating methane releases from peatlands.

Chen, Xi; Slater, Lee

2015-01-01

289

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

290

A Comparison of Carbon Dioxide Net Production in Three Flooded Uplands (FLUDEX, 1999–2002) and a Flooded Wetland (ELARP, 1991–2002) Using a Dynamic Model  

Microsoft Academic Search

We used a dynamic model to estimate the net carbon dioxide production (NCP) of three experimentally flooded upland areas (FLUDEX) over a period of 4 years and NCP from a flooded wetland (ELARP) over 12 years (2 year pre-flooding, 10 years post-flooding). The 3 flooded upland areas had been chosen to have differing amounts of carbon stored in soils and

Raymond Hesslein; Rachel Dwilow; Kenneth Beaty; Mark Lyng

291

Prescribed burning as a natural, long-term experiment in biochar addition - Can prescribed burns contribute to carbon storage in peat soils?  

NASA Astrophysics Data System (ADS)

Prescribed burning is a common land management of UK peatlands where Calluna-vulgaris dominated vegetation is burnt on a cycle of 8 - 25 years. The burning of Calluna by prescribed burning does produce char and thus presents a long-term experiment in biochar addition to a soil. This study will discuss the impacts of biochar additions on soil structure, hydrology, water quality and carbon fluxes from a number of experiments including a study of a chronosequence of nine years. This study proposes that although prescribed burning of moorland dominated by Calluna represents a direct loss of carbon to the atmosphere during the burn itself and destruction of litter production after the burn this loss of carbon is outweighed by the production of both dead biomass and refractory black carbon (char) during the burn itself. The study has produced a model of carbon stock in a peatland under a range of burn frequencies (5- 25 years) and compared this to the carbon stocks of a Calluna-dominated peatland at steady-state biomass. The model was run stochastically with all input parameters being allowed to vary by 50% and run over a period of 51 years. The study shows that: i) In the few years immediately following a burn, there is elevated water colour in soil pore water, but that this is not matched by a rise in dissolved organic carbon (DOC) concentration i.e. the composition varies rather than the absolute concentration. ii) Whilst all the sites examined were net sources of carbon but burnt sites were smaller sources than unburnt sites, i.e. a relative sink was achieved by burning. iii) The conditions under which burning results in a greater annual average sink of carbon than an unburnt site was controlled by the maturity of the Calluna and the extent of severe burning, i.e. the destruction of long term carbon reserves in litter and soil layers. iv) The annual average C flux on an unburnt sink was -8.7 ± 2.6 gC/m2/yr compared to -13.3 ± 2.7 gC/m2/yr for a site burnt every 25 years (equivalent to 100% of the Calluna steady state biomass). The study shows that significant carbon savings could be achieved not by bringing areas of Calluna dominated peatland under burn management but by changing the burn frequency on areas already under burn management and extending it to be as close as possible to the maximum steady-state biomass for the site.

Worrall, F.; Clay, G. D.

2012-04-01

292

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

293

7 CFR 1427.101 - Eligible upland cotton.  

Code of Federal Regulations, 2013 CFR

...2013-01-01 false Eligible upland cotton. 1427.101 Section 1427.101 Agriculture...LOANS, PURCHASES, AND OTHER OPERATIONS COTTON Economic Adjustment Assistance to Users of Upland Cotton § 1427.101 Eligible upland...

2013-01-01

294

7 CFR 1427.103 - Upland cotton Domestic User Agreement.  

Code of Federal Regulations, 2014 CFR

...2014-01-01 2014-01-01 false Upland cotton Domestic User Agreement. 1427.103...LOANS, PURCHASES, AND OTHER OPERATIONS COTTON Economic Adjustment Assistance to Users of Upland Cotton § 1427.103 Upland cotton...

2014-01-01

295

7 CFR 1427.103 - Upland cotton Domestic User Agreement.  

Code of Federal Regulations, 2011 CFR

...2011-01-01 2011-01-01 false Upland cotton Domestic User Agreement. 1427.103...LOANS, PURCHASES, AND OTHER OPERATIONS COTTON Economic Adjustment Assistance to Users of Upland Cotton § 1427.103 Upland cotton...

2011-01-01

296

7 CFR 1427.101 - Eligible upland cotton.  

Code of Federal Regulations, 2011 CFR

...2011-01-01 false Eligible upland cotton. 1427.101 Section 1427.101 Agriculture...LOANS, PURCHASES, AND OTHER OPERATIONS COTTON Economic Adjustment Assistance to Users of Upland Cotton § 1427.101 Eligible upland...

2011-01-01

297

7 CFR 1427.103 - Upland cotton Domestic User Agreement.  

Code of Federal Regulations, 2013 CFR

...2013-01-01 2013-01-01 false Upland cotton Domestic User Agreement. 1427.103...LOANS, PURCHASES, AND OTHER OPERATIONS COTTON Economic Adjustment Assistance to Users of Upland Cotton § 1427.103 Upland cotton...

2013-01-01

298

7 CFR 1427.101 - Eligible upland cotton.  

Code of Federal Regulations, 2010 CFR

...2010-01-01 false Eligible upland cotton. 1427.101 Section 1427.101 Agriculture...LOANS, PURCHASES, AND OTHER OPERATIONS COTTON Economic Adjustment Assistance to Users of Upland Cotton § 1427.101 Eligible upland...

2010-01-01

299

7 CFR 1427.103 - Upland cotton Domestic User Agreement.  

Code of Federal Regulations, 2012 CFR

...2012-01-01 2012-01-01 false Upland cotton Domestic User Agreement. 1427.103...LOANS, PURCHASES, AND OTHER OPERATIONS COTTON Economic Adjustment Assistance to Users of Upland Cotton § 1427.103 Upland cotton...

2012-01-01

300

7 CFR 1427.101 - Eligible upland cotton.  

Code of Federal Regulations, 2014 CFR

...2014-01-01 false Eligible upland cotton. 1427.101 Section 1427.101 Agriculture...LOANS, PURCHASES, AND OTHER OPERATIONS COTTON Economic Adjustment Assistance to Users of Upland Cotton § 1427.101 Eligible upland...

2014-01-01

301

7 CFR 1427.101 - Eligible upland cotton.  

Code of Federal Regulations, 2012 CFR

...2012-01-01 false Eligible upland cotton. 1427.101 Section 1427.101 Agriculture...LOANS, PURCHASES, AND OTHER OPERATIONS COTTON Economic Adjustment Assistance to Users of Upland Cotton § 1427.101 Eligible upland...

2012-01-01

302

7 CFR 1427.103 - Upland cotton Domestic User Agreement.  

Code of Federal Regulations, 2010 CFR

...2010-01-01 2010-01-01 false Upland cotton Domestic User Agreement. 1427.103...LOANS, PURCHASES, AND OTHER OPERATIONS COTTON Economic Adjustment Assistance to Users of Upland Cotton § 1427.103 Upland cotton...

2010-01-01

303

Measurements of CO2 exchange with an automated chamber system throughout the year: challenges in measuring night-time respiration on porous peat soil  

NASA Astrophysics Data System (ADS)

We built an automatic chamber system to measure greenhouse gas (GHG) exchange in forested peatland ecosystems. We aimed to build a system robust enough which would work throughout the year and could measure through a changing snowpack in addition to producing annual GHG fluxes by integrating the measurements without the need of using models. The system worked rather well throughout the year, but it was not service free. Gap filling of data was still necessary. We observed problems in carbon dioxide (CO2) respiration flux estimation during calm summer nights, when a CO2 concentration gradient from soil/moss system to atmosphere builds up. Chambers greatly overestimated the night-time respiration. This was due to the disturbance caused by the chamber to the soil-moss CO2 gradient and consequent initial pulse of CO2 to the chamber headspace. We tested different flux calculation and measurement methods to solve this problem. The estimated flux was strongly dependent on (1) the starting point of the fit after closing the chamber, (2) the length of the fit, (3) the type of the fit (linear and polynomial), (4) the speed of the fan mixing the air inside the chamber, and (5) atmospheric turbulence (friction velocity, u*). The best fitting method (the most robust, least random variation) for respiration measurements on our sites was linear fitting with the period of 120-240 s after chamber closure. Furthermore, the fan should be adjusted to spin at minimum speed to avoid the pulse-effect, but it should be kept on to ensure mixing. If night-time problems cannot be solved, emissions can be estimated using daytime data from opaque chambers.

Koskinen, M.; Minkkinen, K.; Ojanen, P.; Kämäräinen, M.; Laurila, T.; Lohila, A.

2014-01-01

304

Measurements of CO2 exchange with an automated chamber system throughout the year: challenges in measuring nighttime respiration on porous peat soil  

NASA Astrophysics Data System (ADS)

We built an automatic chamber system to measure greehouse gas (GHG) exchange in forested peatland ecosystems. We aimed to build a system robust enough which would work throughout the year and could measure through a changing snowpackin addition to producing annual GHG fluxes by integrating the measurements without the need of using models. The system worked rather well throughout the year, but it was not service free. Gap filling of data was still necessary. We observed problems in carbon dioxide (CO2) flux estimation during calm summer nights, when a CO2 concentration gradient from soil/moss system to atmosphere builds up. Chambers greatly overestimated the nighttime respiration. This was due to the disturbance caused by the chamber to the soil-moss CO2 gradient and consequent initial pulse of CO2 to the chamber headspace. We tested different flux calculation and measurement methods to solve this problem. The estimated flux was strongly dependent on (1) the type of the fit (linear and polynomial), (2) the starting point of the fit after closing the chamber, (3) the length of the fit, (4) the speed of the fan mixing the air inside the chamber, and (5) atmospheric turbulence (friction velocity, u*). The best fitting method (the most robust, least random variation) was linear fitting with the period of 120-240 s after chamber closure. Furthermore, the fan should be adjusted to spin at minimum speed to avoid the pulse-effect, but it should be kept on to ensure mixing. If nighttime problems cannot be solved, emissions can be estimated using daytime data from opaque chambers.

Koskinen, M.; Minkkinen, K.; Ojanen, P.; Kämäräinen, M.; Laurila, T.; Lohila, A.

2013-08-01

305

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

2015-05-01

306

A delta13C record of late Quaternary climate change from tropical peats in southern India  

Microsoft Academic Search

STABLE-ISOTOPE ratios of carbon in soils or lake sediments1-3 and of oxygen and hydrogen in peats4,5 have been found to reflect past moisture variations and hence to provide valuable palaeoclimate records. Previous applications of the technique to peat have been restricted to temperate regions, largely because tropical climate variations are less pronounced, making them harder to resolve. Here we present

R. Sukumar; R. Ramesh; R. K. Pant; G. Rajagopalan

1993-01-01

307

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

NASA Astrophysics Data System (ADS)

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

Macintosh, Katrina Ann; Griffiths, David

2013-04-01

308

Early diagenetic transformations of peat Original research  

E-print Network

;KEY WORDS: bioindicators - carbohydrates - labile organic matter - peat botanical composition bioindicators of OM sources and decay of peat profiles (up to 50 cm in depth) from two moisture conditions parts of the peat. Most bioindicators showed that OM decay increased with depth and was higher

Paris-Sud XI, Université de

309

46 CFR 148.290 - Peat moss.  

Code of Federal Regulations, 2011 CFR

... 5 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

310

Metal removal from wastewater using peat  

Microsoft Academic Search

Peat has been investigated by several researchers as a sorbent for the capture of dissolved metals from wastestreams. Besides being plentiful and inexpensive, peat possesses several characteristics that make it an effective media for the removal of dissolved metal pollutants. The mechanism of metal ion binding to peat remains a controversial area with ion-exchange, complexation, and surface adsorption being the

P. A Brown; S. A Gill; S. J Allen

2000-01-01

311

46 CFR 148.290 - Peat moss.  

Code of Federal Regulations, 2013 CFR

... 5 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

312

Piston corers for peat and lake sediments  

Microsoft Academic Search

Two pistons corers are described which are successful in cuting the wood or undecomposed fibrous peat that characterizes many peat deposits. These modified corers are equipped with a serrated cutting edge, along with modifications to permit the core tube to be rotated back and forth, so that undecomposed fibers and roots can be cut. Complete sections of peat and even

H. E. Jr. Wright; D. H. Mann; P. H. Glaser

1984-01-01

313

46 CFR 148.290 - Peat moss.  

Code of Federal Regulations, 2014 CFR

... 5 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

314

46 CFR 148.290 - Peat moss.  

Code of Federal Regulations, 2012 CFR

... 5 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

315

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...

316

crop science, vol. 51, septemberoctober 2011 Along-term challenge faced by upland cotton (Gossypium  

E-print Network

crop science, vol. 51, september­october 2011 ReseaRch Along-term challenge faced by upland cotton by a fundamental shift in the cotton fiber market from a primarily domestically con- sumed product to one in which.W. Smith, Dep. Soil and Crop Sciences, Texas A&M Univ., College Station, TX 77843; A.H. Paterson, Plant

Chee, Peng W.

317

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

Technology Transfer Automated Retrieval System (TEKTRAN)

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

318

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

319

Experimental evidence for mobility/immobility of metals in peat.  

PubMed

The biogeochemical cycles of most toxic metals have been significantly altered by anthropogenic activities. Anaerobic, rain-fed organic soils are believed to record historical changes in atmospheric pollution. Suspected postdepositional mobility of trace elements, however, hinders the usefulness of peat bogs as pollution archives. To lower this uncertainty, we quantified the mobility of six trace metals in peat during an 18-month field manipulation. A replicated, reciprocal peat transplant experiment was conducted between a heavily polluted and a relatively unpolluted peatland, located 200 km apart in the Czech Republic (Central Europe). Both peatlands were Sphagnum-derived, lawn-dominated, and had water table close to the surface. A strikingly different behavior was observed for two groups of elements. Elements of group I, Fe and Mn, adjusted their abundances and vertical patterns to the host site, showing an extremely high degree of mobility. In contrast, elements of group II, Pb, Cu, Zn, and Ti, preserved their original vertical patterns at the host site, showing a high degree of immobility. Our experimental results suggest that not just lead, but also copper and zinc concentration profiles in peat are a reliable archive of temporal pollution changes within a wide pH range (2.5-5.8). PMID:21761934

Novak, Martin; Zemanova, Leona; Voldrichova, Petra; Stepanova, Marketa; Adamova, Marie; Pacherova, Petra; Komarek, Arnost; Krachler, Michael; Prechova, Eva

2011-09-01

320

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

321

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

322

The role of condensed organic matter in the nonlinear sorption of hydrophobic organic contaminants by a peat and sediments.  

PubMed

This study examines the effect of soil organic matter heterogeneity on equilibrium sorption and desorption of phenanthrene, naphthalene, 1,3,5-trichlorobenzene (1,3,5-TCB), and 1,2-dichlorobenzene (1,2-DCB) by soils and sediments. Two estuary sediments, a Pahokee peat (PP; Euic, hyperthermic Lithic Haplosaprist), and two subsamples (base- and acid-treated peat [TP] and acid-treated peat [FP]) of the peat were used as the sorbents. The contents of black carbon particles were quantified with a chemical extraction method. Petrographical examinations revealed the presence of the condensed soil and sediment organic matter (SOM) in Pahokee peat. The Freundlich isotherm model in two different forms was used to fit both sorption and desorption data. The results show that the sorption and desorption isotherms are generally nonlinear and that the apparent sorption-desorption hysteresis is present for phenanthrene and TCB. Detailed analysis of sorption data for the tested sorbent-sorbate systems indicates that black carbon is probably responsible for sorption isotherm nonlinearity for the two sediments, whereas the humic substances and kerogen may play the dominant role in nonlinear sorption by the peat. This investigation suggests that the microporosity of SOM is important for the hydrophobic organic contaminant (HOC) sorption capacity on the peat. PMID:12469845

Ran, Yong; Huang, Weilin; Rao, P S C; Liu, Dehan; Sheng, Guoying; Fu, Jiamo

2002-01-01

323

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

324

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

PubMed Central

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

325

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

NASA Astrophysics Data System (ADS)

Tropical peat swamp forests in their natural state are important reservoir of biodiversity, carbon and water. However, they are rapidly vanishing due to agricultural conversion (mainly to oil palms), logging, drainage and fire. Peat swamp forests constitute an important contribution to global and regional biodiversity, providing an habitat to rare and threatened species. They encompass a sequence of forest types from the perimeter to the center of mildely elevated domes, and at our site in Brunei, are host to Shorea Albida trees (Anderson, 1983). They constitute a large terrestrial carbon reservoir (tropical peat soils contain up to 70 Pg C, which accounts for 20% of global peat soil carbon and 2% of the global soil carbon (Hirano et al., 2007)). In tropical peat swamp forests, the most important factors controling organic matter accumulation, as well as the biodiversity and structure of the forest, are hydrology and nutrients availability (Page et al., 1999). Study of pore water in peat swamp forest can provide key information on carbon cycle, including biomass production, organic matter decomposition and leaching of carbon in draining water. However, data on pore water chemistry and nutrient concentrations in pristine tropical peatlands, as well as the effect of forest exploitation are scarce. The study area is located in the Belait district in Brunei Darussalam in Borneo Island. Brunei is perhaps the best of the regional guardians of peat forest systems; potentially irreversible damage to peat forest ecosystems has been widespread elsewhere. Two sites, one pristine dome and a logging concession, are being investigated. In order to assess the chemical status of the peat soil, pore water is sampled at different depth along the dome radius. The chemistry of pore water, including pH, conductivity, dissolved oxygen, concentration of major elements, as well as organic carbon content and properties are analyzed. References: Anderson, 1983. The tropical peat swamp of western malesia. Ecosystems of the world 4b, 181-189. Hirano et al., 2007. Carbon dioxide balance of a tropical peat swamp forest in Kalimantan, Indonesia. Global Change Biology 13, 412-425. Page et al., 1999. Interdependance of peat and vegetation in a tropical peat swamp forest. Phil. Trans. R. Soc. Lond. 354, 1885-1897.

Gandois, L.; Cobb, A.; Abu Salim, K.; Chieng Hei, I.; Lim Biaw Leng, L.; Corlett, R.; Harvey, C.

2010-12-01

326

7 CFR 1205.305 - Upland cotton.  

Code of Federal Regulations, 2014 CFR

...2014-01-01 2014-01-01 false Upland cotton. 1205.305 Section 1205.305 Agriculture...MISCELLANEOUS COMMODITIES), DEPARTMENT OF AGRICULTURE COTTON RESEARCH AND PROMOTION Cotton Research and Promotion Order Definitions...

2014-01-01

327

7 CFR 1205.305 - Upland cotton.  

Code of Federal Regulations, 2011 CFR

...2011-01-01 2011-01-01 false Upland cotton. 1205.305 Section 1205.305 Agriculture...MISCELLANEOUS COMMODITIES), DEPARTMENT OF AGRICULTURE COTTON RESEARCH AND PROMOTION Cotton Research and Promotion Order Definitions...

2011-01-01

328

7 CFR 1205.305 - Upland cotton.  

Code of Federal Regulations, 2013 CFR

...2013-01-01 2013-01-01 false Upland cotton. 1205.305 Section 1205.305 Agriculture...MISCELLANEOUS COMMODITIES), DEPARTMENT OF AGRICULTURE COTTON RESEARCH AND PROMOTION Cotton Research and Promotion Order Definitions...

2013-01-01

329

7 CFR 1205.305 - Upland cotton.  

Code of Federal Regulations, 2012 CFR

...2012-01-01 2012-01-01 false Upland cotton. 1205.305 Section 1205.305 Agriculture...MISCELLANEOUS COMMODITIES), DEPARTMENT OF AGRICULTURE COTTON RESEARCH AND PROMOTION Cotton Research and Promotion Order Definitions...

2012-01-01

330

7 CFR 1205.305 - Upland cotton.  

Code of Federal Regulations, 2010 CFR

...2010-01-01 2010-01-01 false Upland cotton. 1205.305 Section 1205.305 Agriculture...MISCELLANEOUS COMMODITIES), DEPARTMENT OF AGRICULTURE COTTON RESEARCH AND PROMOTION Cotton Research and Promotion Order Definitions...

2010-01-01

331

77 FR 19925 - Upland Cotton Base Quality  

Federal Register 2010, 2011, 2012, 2013, 2014

...CFR Part 1427 RIN 0560-AI16 Upland Cotton Base Quality AGENCY: Commodity Credit Corporation...specific quality characteristics of certain base quality grades to simply a reference to the ``base quality'' of the grade without further...

2012-04-03

332

Geoelectrical properties of peat in a northern peatland: Implications for peat basin formation, vegetation patterning, pool formation, and carbon gas evaluation  

Microsoft Academic Search

Peatlands are unique ecosystems that represent major terrestrial stores of soil carbon. Peatlands are important sources of atmospheric methane but their response to global warming still presents major uncertainties. A better understanding of the geoelectrical properties of peat and the in-situ formation of surficial features in peatlands can improve the current knowledge of the hydrology, nutrient dynamics, stratigraphy, and biogenic

Xavier Comas

2005-01-01

333

Utilization of peat as a fuel  

SciTech Connect

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

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

1981-10-01

334

Influence of forest management on the changes of organic soil properties in border part of Kragle Mokradlo Peatland (Stolowe Mountains National Park, Poland)  

Microsoft Academic Search

SUMMARY The aim of this work was to determine the properties of organic soils modified by man, muddy and fluvial process. Peat horizons were analyzed and classified by types - and species of peat. Three profiles of shallow peat and peaty gley soils identified. Investigation showed that organic soil developed on a sandy weathered sandstone base according to oligotrophic type

A. Bogacz; M. Roszkowicz

2009-01-01

335

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

PubMed

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

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

2012-08-01

336

Impact of subjacent rocks at the water and air regime of the depleted peat deposits  

NASA Astrophysics Data System (ADS)

At the depleted peat deposits (after peat extraction), where the residual layer of peat with the thickness of about 0,5 meters is laid at the well water permeable rocks, vegetation typical for dry conditions is developed in case of good drainage conditions; birch trees, willow, alder-trees and buckthorn prevail in this vegetation. Water and air regime is characterized here by good aeration with prevailing of oxidative processes. If water regime is regulated, these depleted peat areas are suitable for agricultural and forest lands; however, necessity of transformation of these depleted lands into forest and agricultural lands must be ecologically and economically justified. If the residual layer of peat with the thickness of 0,05-0,3 m is based at the sapropel or peat sapropel, contrast amphibiotic water and air regime with strong fluctuation of oxidative and restoration process depending on the weather conditions is formed; this regime is formed without artificial increase of the ground waters level. This does not allow bog vegetation or vegetation typical for dry conditions to develop. Thus, within 20 and more years after completion of peat extraction, such areas are not covered by vegetation in spite of favorable agro-chemical qualities of peat layer and favorable for vegetation chemical composition of soil and ground waters. Depleted peat deposits, that are based at the sapropel, are not suitable for agricultural use, because agricultural vegetation requires stable water and air regime with good aeration and oxidative and restoration potential within 400-750 mV. Contrast amphibiotic water and air regime of the depleted peat deposits that are based at sapropel excludes possibility to use them as agricultural lands. Because of this reason, areas with residual peat layer that are based at sapropel are not suitable for forest planting. Due to periodic increase of ground waters level, rot systems of the plants can not penetrate into the required depth, and mechanical solidity of the residual low-powered peat layer does not facilitate formation of wind stable plats. Besides, due to the fact that this territory was formed at the place of former ancient lake, there is a possibility that this territory will be flooded during water full periods for long periods because columbine from the nearby territories and this will lead to the death of forest plants. It is more profitable to use these areas for re-wetting or for creation of water basins.

Rakovich, V. A.

2009-04-01

337

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

338

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

339

Freshwater peat on the continental shelf  

USGS Publications Warehouse

Freshwater peats from the continental shelf off northeastern United States contain the same general pollen sequence as peats from ponds that are above sea level and that are of comparable radiocarbon ages. These peats indicate that during glacial times of low sea level terrestrial vegetation covered the region that is now the continental shelf in an unbroken extension from the adjacent land areas to the north and west.

Emery, K.O.; Wigley, R.L.; Bartlett, A.S.; Rubin, M.; Barghoorn, E.S.

1967-01-01

340

Peat mining and natural resources: peat mining task force report. Final report  

Microsoft Academic Search

In this report the peat mining task force reviews the potential impacts of peat mining in North Carolina and the adequacy of state laws for assuring that mining is carried out in a way that protects natural resources. Problems arising from the proximity of peat to estuarine waters are given special attention. A general management framework based on the existing

J. F. Smith; D. W. Owens

1983-01-01

341

Peat bog restoration by floating raft formation: the effects of groundwater and peat quality  

Microsoft Academic Search

Summary 1. A prerequisite for the restoration of desiccated bog remnants is rewetting the peat surface. Frequently in Europe, extensive areas are flooded in order to maximize water retention, and growth of peat mosses is often observed in the shallow zones. In deeper waters, regeneration appears to depend on whether residual peat will become buoyant and form floating rafts. 2.

Alfons J. P. Smolders; Hilde B. M. Tomassen; Leon P. M. Lamers; Bart P. Lomans; Jan G. M. Roelofs

2002-01-01

342

metry and conventional radiocarbon dating of bulk peat samples from the lowest visually apparent peat  

E-print Network

#12;metry and conventional radiocarbon dating of bulk peat samples from the lowest visually apparent peat horizon in each core. Substantially older radiocarbon ages from organic-rich gytjja (mineral peat- lands throughout the WSL, for a total of 29,350 measurements digitized. (ii) Our own field data

Gillespie, Rosemary

343

Biosorption of Metallic Elements onto Fen Peat  

NASA Astrophysics Data System (ADS)

Industrial development and anthropogenic activity have a huge impact on the environment, forcing society to find new and cost-effective environment treatment technologies. One of the most effective and environmentally friendly methods is the use of biosorbents, for which peat is one of the most cost-effective materials. The adsorption capabilities of peat sediments are well known; however, mainly raised bog peat is used for environmental treatment, and thus the abilities of fen peat are underestimated. The aim of this research was to assess the fen peat suitability as an adsorbent for metallic elements. In this study we have determined the sorption characteristics of Ca, Mg, K, Na, Cu and Pb and results show that fen peat deposits have a huge variability as a biosorbent due to their variable botanical composition and complex properties, for instance, under equal conditions, wood-sedge peat can have higher lead adsorption capacity than wood peat. However, due to its natural content of metallic elements, the sorption capacity overall is lower than it is for raised bog peat, although the high pH reaction encourage a high mobility metals.

Krumins, Janis; Robalds, Artis

2014-12-01

344

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

345

Assessment of the peat resources of Florida, with a detailed survey of the northern everglades  

SciTech Connect

Available data, including previous publications, modern soil surveys, and detailed coring in the Northern Everglades for this project have been used to update information on Florida's peat resources. It is now estimated that Florida could, if no other constraints existed, produce 606 million tons of moisture-free fuel-grade peat, which may yield approximately 10.0 x 10/sup 15/ Btu of energy. These estimates are much lower than previously published projections for the state. The principal effort of this survey was in the largest peat region of the state, the Northern Everglades of Palm Beach and adjacent counties, where more than 800 core holes were drilled. Based on analyses of these cores, the Northern Everglades is now estimated to contain 191 million tons of moisture-free peat, with a potential energy yield of 2.98 x 10/sup 15/ Btu. These values are considerably less than previously published estimates, probably due to bacterial oxidation and other forms of drainage-induced subsidence in the Everglades agricultural areas. The present fuel-peat resources of the Northern Everglades occur in 19 separate deposits. Of these, the deposits in the Port Mayaca, Bryant, Six Mile Bend, and Loxahatchee Quadrangles comprise the highest concentration of the resource. These lands are generally privately owned and used for sugar cane and other crops, and the conversion of these lands to peat removal seems unlikely. It seems even less likely that the extensive peat deposits within the Loxahatchee National Wildlife Refuge will be available for fuel use, barring a dire national emergency. The utilization of peat as a fuel must be approached with caution and careful study; large scale use may require state or federal action. 34 references.

Griffin, G.M.; Wieland, C.C.; Hood, L.Q.; Goode, R.W. III; Sawyer, R.K.; McNeill, D.F.

1982-01-01

346

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

347

Dynamic tests of pipe pile in saturated peat  

SciTech Connect

Dynamic quick-release and forced-harmonic vibration tests were performed on a steel pipe embedded in soft saturated peat. The translational and rotational pile-head impedances (stiffness and damping values) estimated from the forced-harmonic vibration tests were independent of frequency between 1.8 Hz and 3 Hz, the frequency range of the tests. These impedances were generally similar to those estimated from quick-release tests at initial pile-head offsets similar to the harmonic displacements generated during the forced-vibration tests. However, dynamic translational stiffness was less than the tangent stiffness obtained from earlier static load tests on the pile, a result attributed to cyclic degradation of the peat and possible experimental error. The calibration of simple theoretical models to the dynamic test data also indicated that large reductions in the apparent soil modulus occurred, and that this reduction was greatest near the ground surface where the pile deflections were largest. This observation and the low hysteretic damping indicated by the models suggest that a water-filled gap may have formed between the pile and the peat during the dynamic tests.

Crouse, C.B.; Mitchell, R. (Dames and Moore, Seattle, WA (United States)); Kramer, S.L. (Univ. of Washington, Seattle, WA (United States). Dept. of Civil Engineering); Hushmand, B. (California Inst. of Tech., Pasadena, CA (United States))

1993-10-01

348

Monitoring the effects of manure policy in the Peat region, Netherlands  

NASA Astrophysics Data System (ADS)

Total N concentrations in farm ditches in the Peat region of the Netherlands are on the average twice as high as the Good Ecological Potential value of the Water Framework Directive. Since ditches are connected to regional surface water, they may contribute to eutrophication. The minerals policy aims to improve the water quality. In the Netherlands, the effectiveness of the minerals policy on water quality is evaluated with data from the National Minerals Policy Monitoring Programme (LMM). This regards farm data on the quality of water leaching from the root zone and on farm practices. The soil balance nitrogen surpluses decreased between 1996 and 2003 on dairy farms in the Peat region. However, no effect on root zone leaching was found. This study aims to show how monitoring in the Peat region can be improved in order to link water quality to agricultural practice. Contrary to the other Dutch regions, nitrate concentrations in root zone leaching on farms in the Peat region are often very low (90% of the farms below 25 mg/l) due to the reduction of nitrate (denitrification). The main nitrogen (N) components in the peat region waters are ammonium and organic N. Total N is therefore a better measure for N concentrations in the Peat region. The ammonium concentration in groundwater in Dutch peat soils increases with depth. It is assumed that the deeper ammonia-rich water is older and relates to anaerobic peat decomposition instead of agricultural practice. Recent infiltrated low-ammonium water, lies like a thin freshwater lens on the older water. In the Peat region, root zone leaching is monitored by taking samples from the upper meter of groundwater. Unintended, often both lens water and older water are sampled and this distorts the relation between agricultural practice and water quality. In the Peat region, the N surplus is transported with the precipitation surplus to ditches. The relation between the N surplus and the total N in ditch water is therefore better than between N surplus and total N in root zone leaching. The precipitation surplus flows to ditches directly or via open field drains. However, the ditches may be fed partly with older water (seepage of groundwater). In the open field drain only recent water will occur. We expect that monitoring the water quality of the open field drains may even better reflect changes in agricultural practices. These data may also improve the understanding of contribution of agricultural nitrogen and natural nitrogen, necessary to develop measures to decrease the total-N concentration in ditch water.

Hooijboer, Arno; Buis, Eke; Fraters, Dico; Boumans, Leo; Lukacs, Saskia; Vrijhoef, Astrid

2014-05-01

349

A Comparison of Carbon Dioxide Net Production in Three Flooded Uplands (FLUDEX, 1999–2002) and a Flooded Wetland (ELARP, 1991–2002) Using a Dynamic Model  

Microsoft Academic Search

\\u000a We used a dynamic model to estimate the net carbon dioxide production (NCP) of three experimentally flooded upland areas (FLUDEX)\\u000a over a period of 4 years and NCP from a flooded wetland (ELARP) over 12 years (2 year pre-flooding, 10 years post-flooding).\\u000a The 3 flooded upland areas had been chosen to have differing amounts of carbon stored in soils and

Raymond H. Hesslein; Rachel A. Dwilow; Kenneth G. Beaty; Mark E. Lyng

350

Implications of changing from grazed or semi-natural vegetation to forestr y for carbon stores and fluxes in upland soils Hydrol. Earth Syst. Sci., 11(1), 6176, 2007  

E-print Network

on modelling approaches which assume that afforestation of organo-mineral soils is carbon neutral. This review following afforestation is examined in the context of international studies. Secondly, UK data are assessed to identify the likely responses of the fluxes to afforestation of organo-mineral soils

Paris-Sud XI, Université de

351

CO2 Efflux from Cleared Mangrove Peat Catherine E. Lovelock1  

E-print Network

of Arctic Biology, University of Alaska Fairbanks, Fairbanks, Alaska, United States of America, 3 Smithsonian Environmental Research Center, Edgewater, Maryland, United States of America Abstract Background to baseline levels within 2 days. Conclusions/Significance: Deforesting mangroves that grow on peat soils

Ruess, Roger W.

352

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

353

Hydrological studies on blanket peat: the significance of the acrotelm-catotelm model  

Microsoft Academic Search

Summary 1 Runoff production in blanket peat catchments of the northern Pennine hills, UK was measured through monitoring and experimentation at the plot, hillslope and catchment scale. Water flow from soil pipes was measured in one of the study catchments and overland flow, throughflow and water table were measured in runoff plots; rainfall simu- lation and tension-infiltrometry provided information on

J. Holden; T. P. Burt

2003-01-01

354

Sago (Metroxylon sagu Rottb.) growth is affected by weeds in a tropical peat swamp in Thailand  

Microsoft Academic Search

The effect of weeds on sago palms (Metroxylon sagu Rottb.) growing in tropical peat soils was examined in the field and in pots. In the field, 31 species of weeds were found, however, Fimbristylis umbellaris (Cyperraceae) and Leersia hexandra (Gramineae) were the most abundant species. Sago heights and weed populations seemed to be correlated. The field experiment showed that high

Monrawee Yanbuaban; Mitsuru Osaki; Tanit Nuyim; Jumpen Onthong; Toshihiro Watanabe

2007-01-01

355

CHARACTERIZATION OF A HORTICULTURAL PEAT FOR TREATING MINING ASAPO, Emmanuel S and COLES, Cynthia A  

E-print Network

Contamination of soil, surface waters and groundwater by heavy metals is gradually on the increase especially the properties of peat in order to capture dissolved heavy metals. This paper investigates the surface process and retentive capability for removing metallic ions in wastewater treatment. Keywords Adsorbent

Coles, Cynthia

356

Bioaerosols in Peat Moss Processing Plants  

Microsoft Academic Search

Peat moss is organic matter colonized by large numbers of microorganisms. Storage prior to its processing may result in massive microbial growth. These biological contaminants can become airborne during processing. Our goals were (a) to evaluate concentrations of bioaerosols (inhalable dust, molds, bacteria) in peat moss processing plants that used dust removing systems, and (b) to evaluate the presence of

Anne Mériaux; Pascal Pageau; Yvon Cormier; Nicole Goyer; Caroline Duchaine

2006-01-01

357

Acidophilic Methanotrophic Communities from Sphagnum Peat Bogs  

Microsoft Academic Search

Highly enriched methanotrophic communities (>25 serial transfers) were obtained from acidic ombrotro- phic peat bogs from four boreal forest sites. The enrichment strategy involved using media conditions that were associated with the highest rates of methane uptake by the original peat samples, namely, the use of diluted mineral medium of low buffering capacity, moderate incubation temperature (20°C), and pH values

SVETLANA N. DEDYSH; NICOLAI S. PANIKOV; JAMES M. TIEDJE

1998-01-01

358

Mineral resource of the month: peat  

USGS Publications Warehouse

Peat is a natural organic material of botanical origin, harvested from deposits in bogs and fens. Commercial deposits form from the incomplete decomposition of plant matter under anaerobic conditions and gradually accumulate to form peat over about a 5,000-year period.

Jasinski, Stephen M.

2008-01-01

359

Genetic variation for yield and fiber quality response to supplemental irrigation within the Pee Dee Upland cotton germplasm collection  

Technology Transfer Automated Retrieval System (TEKTRAN)

Water availability is a major factor influencing the development of upland cotton (Gossypium hirsutum L.) cultivars and sustainable cotton production in the southeast USA because of endemic, intermittent drought events occurring in the region resulting from shallow, coarse textured soils and irregul...

360

Woody debris along an upland chronosequence in boreal Manitoba and its impact on long-term carbon storage  

Microsoft Academic Search

This study investigated the role of fire-killed woody debris as a source of soil carbon in black spruce (Picea mariana (Mill.) BSP) stands in Manitoba, Canada. We measured the amount of standing dead and downed woody de- bris along an upland chronosequence, including wood partially and completely covered by moss growth. Such woody debris is rarely included in measurement protocols

K. L. Manies; J. W. Harden; B. P. Bond-Lamberty; K. P. O'Neill

2005-01-01

361

History and Vulnerability of Permafrost in Upland and Lowland Boreal Landscapes (Invited)  

NASA Astrophysics Data System (ADS)

The history of permafrost aggradation and degradation in boreal landscapes can be interpreted through surface geomorphology, ground-ice characteristics, geochemistry, and ecological indicators. This history, which varies greatly in relation to topography, surficial materials, and ecological succession, can be simplified into four basic patterns involving rocky uplands, loamy uplands, gravelly-sandy lowlands, and peaty-loamy lowlands. In rocky uplands, permafrost conditions reflect fluctuations only over decades to century-long periods due to low latent heat of ice-poor soils and frequent fires, and history is poorly preserved. In loamy uplands with loess, water-shedding slopes, surface thermal properties, ecological recovery, and high latent heat in underlying massive ice make permafrost highly resilient. Consequently, permafrost history is well preserved as cryostructures, isotopic signatures, and buried soils. Permafrost can persist over tens to perhaps hundreds of thousands of years. In gravelly-sandy lowlands with fluvial gravels and eolian sand sheets, permafrost presence fluctuates over century periods, but because permafrost can affect surface and groundwater, changing water levels leave a legacy of plant macrofossils from aquatic and terrestrial ecosystems that can be used interpreting permafrost history. In peaty-loamy lowlands with lowland loess and abandoned floodplain deposits, water-impounding topography and permafrost-inducing soil thermal properties are conducive to permafrost fluctuations over decadal, century, and millennial periods that leave a rich legacy of plant materials indicative of specific conditions of permafrost formation and degradation. These varying responses of permafrost to environmental changes complicate the assessment of the role of permafrost in the sequestration and release of soil carbon into the atmosphere and surface waters.

Jorgenson, M. T.; Kanevskiy, M. Z.; Shur, Y.; Harden, J. W.; O'Donnell, J.; Wickland, K. P.; Ewing, S. A.; Striegl, R. G.; Zhuang, Q.

2010-12-01

362

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

363

Hydraulic Conductivity of Riparian Mangrove Forest Peat Adjacent to the Harney River, Everglades National Park: A Comparative Field Study of Field Saturated and Saturated Hydraulic Conductivity Methods.  

NASA Astrophysics Data System (ADS)

The Shark-Harney river estuary is located in the southwest region of Everglades National Park and is the principle outflow for the freshwater everglades slough. Periodic tidal inundation, rainfall and overland freshwater flow are the forcing functions on surface soil infiltration and drainage in the adjacent estuary mangrove forest peat. Empirical soil hydraulic conductivity (K) for the mangrove peat soil is needed for hydrologic modeling efforts such as "The Tides and Inflows in the Mangroves of the Everglades" (TIME). South Florida has a bi-seasonal weather pattern of a dry and mild winters and a wet tropical summers. During the drier winter months (November-May), the mangrove peat has a 30-60 cm, unsaturated vadose zone and in the wet summer months (June-October), the peat is totally saturated. This study's purpose is to determine reliable values of soil hydraulic conductivity for mangrove peat under both the unsaturated Kfs and saturated Ksat soil conditions. Rycroft (1975) reported that field measurements are the preferred method of testing hydraulic conductivity of peat. The principle field method used to determining soil hydraulic conductivity Kfs under unsaturated conditions utilized a cylindrical permeameter (Guelph Permeameter) and the auger-hole method was used to determine soil hydraulic conductivity Ksat under saturated soil conditions. The hydraulic conductivity K samples were taken along a 300-meter transect, perpendicular to the south Harney riverbank through a mixed mangrove riparian forest and ending in a freshwater sawgrass prairie. Initial measurements were recorded in May-June 2001. A second year measurement set will be collected in March-April 2002. Hydraulic conductivity K measurements were observed in shallow peat holes (15 cm) at five equally spaced sample sites (60 m) from the river edge. Soil cores were taken at each sampling site to determine soil profile and bulk density.

Anderson, G. H.; Smith, T. J.

2002-05-01

364

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

365

Restoring afforested peat bogs: results of current research  

E-print Network

Restoring afforested peat bogs: results of current research The value of peat bogs as open habitats may suffice on lowland raised bogs. Damming furrows is ineffective if the peat is severely cracked sundew, Drosera anglica #12;Introduction In their natural state, peat bogs provide unique habitats

366

Evaluating approaches for estimating peat depth  

NASA Astrophysics Data System (ADS)

Estimates of peat depth are required to inform understanding of peatland development, functioning, and ecosystem services such as carbon storage. However, there is a considerable lack of peat depth data at local, national, and global scales. Recent studies have attempted to address this knowledge deficit by using manual probing and ground-penetrating radar (GPR) to estimate depth. Despite increasing application, little consideration has been given to the accuracy of either of these techniques. This study examines the accuracy of probing and GPR for measuring peat depth. Corresponding GPR and probing surveys were carried out at a catchment scale in a blanket peatland. GPR depth estimations, calibrated using common midpoint (CMP) surveys, were found to be on average 35% greater than probe measurements. The source of disagreement was found to be predominantly caused by depth probes becoming obstructed by artifacts within the peat body, although occasionally probing rods also penetrated sediments underlying the peat. Using the Complex Refractive Index Model, it was found that applying a single velocity of 0.036 m ns-1 across a single site may also result in -8 to +17% error in estimation of peat depth due to spatial variability in water content and porosity. It is suggested that GPR calibrated at each site using CMP surveys may provide a more accurate method for measuring peat depth.

Parry, L. E.; West, L. J.; Holden, J.; Chapman, P. J.

2014-04-01

367

CAP and the Uplands Robert Brotherton  

E-print Network

CAP and the Uplands Robert Brotherton Principal Officer Agriculture and Land Management #12;#12;Why impacts #12;2003 Reforms Decoupling Diversification Safe food Animal Welfare Environmental improvements #12;Pillar I and Pillar II of CAP Pillar 1 production based (blue box) ­SFP Pillar II rural

Quinton, John

368

Mars Meteorite Statistics and the Martian Uplands  

NASA Astrophysics Data System (ADS)

A significant fraction of Mars, perhaps 30-50%, is covered by heavily cratered uplands. The high crater densities constrain their ages to be greater than 2 Gy or even 3 Gy. A somewhat smaller fraction is covered by young lava plains with crater retention ages less than 1.5 Gy, and even less than 0.5 Gy over wide areas of Tharsis, Amazonis, and Elysium. These young ages for basaltic lava plains agree with ages of Martian basaltic meteorites. The problem is that all but one of the 4 to 8 sample sites of SNCs lie in the age range of 0.2 to 1.3 Gy, and the other one is a sample of primordial crust of 4.5 Gy age. These data suggest that the Martian uplands do not efficiently launch meteorites. MGS and Odyssey data imply that the upper latitude Hesperian/Noachian Martian uplands, older than 2 to 3 Gy, are impregnated with near-surface ice. Furthermore, direct geometric considerations of crater areal coverage show that they have been pulverized into megaregolith, although that material itself may be recemented by salts, carbonates, and ice. Thus, the Martian uplands probably do not launch meteorites as effectively as the young basaltic plains, and those that are launched may be rich in rock types that are unfamiliar as meteorites. These considerations should affect future meteorite collection strategies.

Hartmann, W. K.

2002-01-01

369

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 ...

370

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

371

HYDRAULIC CONDUCTIVITY OF ESSENTIALLY SATURATED PEAT  

SciTech Connect

The Savannah River National Laboratory measured the hydraulic conductivity of peat samples using method ASTM D4511-00. Four samples of peat were packed into 73mm diameter plastic tubes and saturated from the bottom up with water. The columns were packed with Premier ProMoss III TBK peat to a dry density of approximately 0.16 gm/cc (10 lb/ft3). One column was packed using oven dried peat and the other 3 were packed using as delivered peat. The oven dried sample was the most difficult to saturate. All of the peat samples expanded during saturation resulting in a sample length (L) that was longer than when the sample was initially packed. Table 1 contains information related to the column packing. After saturation the hydraulic conductivity test was conducted using the apparatus shown in Figure 1. Three of the samples were tested at 2 different flow conductions, 1 high and 1 low. Table 2 and Figure 2 contain the results of the hydraulic conductivity testing. Each test was run for a minimum of 40 minutes to allow the test conditions to stabilize. The hydraulic conductivity at the end of each test is reported as the hydraulic conductivity for that test. The hydraulic conductivity of the 4 peat samples is 0.0052 {+-} 0.0009 cm/sec. This result compares well with the hydraulic conductivity measured in the pilot scale peat bed after approximately 2 months of operation. The similarity in results between the dry pack sample and moist pack samples shows the moisture content at the time of packing had a minimal effect on the hydraulic conductivity. Additionally, similarity between the results shows the test is reproducible. The hydraulic conductivity results are similar to those reported by other tests of peat samples reported in the literature.

Nichols, R

2008-02-27

372

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

PubMed

Peatlands store approximately 30% of global soil carbon, most in moss-dominated bogs. Future climatic changes, such as changes in precipitation patterns and warming, are expected to affect peat bog vegetation composition and thereby its long-term carbon sequestration capacity. Theoretical work suggests that an episode of rapid environmental change is more likely to trigger transitions to alternative ecosystem states than a gradual, but equally large, change in conditions. We used a dynamic vegetation model to explore the impacts of drought events and increased temperature on vegetation composition of temperate peat bogs. We analyzed the consequences of six patterns of summer drought events combined with five temperature scenarios to test whether an open peat bog dominated by moss (Sphagnum) could shift to a tree-dominated state. Unexpectedly, neither a gradual decrease in the amount of summer precipitation nor the occurrence of a number of extremely dry summers in a row could shift the moss-dominated peat bog permanently into a tree-dominated peat bog. The increase in tree biomass during drought events was unable to trigger positive feedbacks that keep the ecosystem in a tree-dominated state after a return to previous 'normal' rainfall conditions. In contrast, temperature increases from 1 °C onward already shifted peat bogs into tree-dominated ecosystems. In our simulations, drought events facilitated tree establishment, but temperature determined how much tree biomass could develop. Our results suggest that under current climatic conditions, peat bog vegetation is rather resilient to drought events, but very sensitive to temperature increases, indicating that future warming is likely to trigger persistent vegetation shifts. PMID:23526779

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

2013-07-01

373

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

374

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

375

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

376

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

377

Upland forests of the American/Pacific islands: Research opportunities in Micronesia and American Samoa. Forest Service general technical report (Final)  

SciTech Connect

The Upland forests of Micronesia and American Samoa can provide many social, ecological, and esthetic benefits for island inhabitants. Substantial upland areas (the majority of acreage on some islands) are now occupied by secondary and grassland/savanna vegetation: such areas represent opportunities for restoration, with both native forest cover and plantations of introduced species. The review briefly describes characteristics of the islands and the nature of existing and potential upland forests, including the most common upland tree species. Principal information needs and research opportunities are discussed for 10 subjects: watershed rehabilitation, forest restoration in secondary vegetation areas, basic ecology, soils and nutrient relationships, damaging agents, forest inventory and productivity assessment, silvicultural systems, valuation of forest products and services, threatened and endangered species, and description and protection of native forest habitats.

DeBell, D.S.; Whitesell, C.D.

1993-07-01

378

Redox Fluctuations Frame Microbial Community Impacts on N-cycling Rates in a Humid Tropical Forest Soil  

Microsoft Academic Search

Fluctuating soil redox regimes may facilitate the co-occurrence of microbial nitrogen transformations with significantly different sensitivities to soil oxygen availability. In an upland humid tropical forest, we explored the impact of fluctuating redox regimes on gross nitrogen cycling rates and microbial community composition. Our results suggest that the rapidly fluctuating redox conditions that characterize these upland soils allow anoxic and

Jennifer Pett-Ridge; Whendee L. Silver; Mary K. Firestone

2006-01-01

379

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

380

Experiments and Observation of Peat Smouldering Fires   

E-print Network

If a subsurface layer of peat is ignited, it smoulders (flameless combustion) slowly but steadily. These fires propagate for long periods of time (days, weeks, even years), are particularly difficult to extinguish and can spread over very extensive...

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

2007-01-30

381

Actinobacterial Nitrate Reducers and Proteobacterial Denitrifiers Are Abundant in N2O-Metabolizing Palsa Peat  

PubMed Central

Palsa peats are characterized by elevated, circular frost heaves (peat soil on top of a permanently frozen ice lens) and are strong to moderate sources or even temporary sinks for the greenhouse gas nitrous oxide (N2O). Palsa peats are predicted to react sensitively to global warming. The acidic palsa peat Skalluvaara (approximate pH 4.4) is located in the discontinuous permafrost zone in northwestern Finnish Lapland. In situ N2O fluxes were spatially variable, ranging from 0.01 to ?0.02 ?mol of N2O m?2 h?1. Fertilization with nitrate stimulated in situ N2O emissions and N2O production in anoxic microcosms without apparent delay. N2O was subsequently consumed in microcosms. Maximal reaction velocities (vmax) of nitrate-dependent denitrification approximated 3 and 1 nmol of N2O per h per gram (dry weight [gDW]) in soil from 0 to 20 cm and below 20 cm of depth, respectively. vmax values of nitrite-dependent denitrification were 2- to 5-fold higher than the vmax nitrate-dependent denitrification, and vmax of N2O consumption was 1- to 6-fold higher than that of nitrite-dependent denitrification, highlighting a high N2O consumption potential. Up to 12 species-level operational taxonomic units (OTUs) of narG, nirK and nirS, and nosZ were retrieved. Detected OTUs suggested the presence of diverse uncultured soil denitrifiers and dissimilatory nitrate reducers, hitherto undetected species, as well as Actino-, Alpha-, and Betaproteobacteria. Copy numbers of nirS always outnumbered those of nirK by 2 orders of magnitude. Copy numbers of nirS tended to be higher, while copy numbers of narG and nosZ tended to be lower in 0- to 20-cm soil than in soil below 20 cm. The collective data suggest that (i) the source and sink functions of palsa peat soils for N2O are associated with denitrification, (ii) actinobacterial nitrate reducers and nirS-type and nosZ-harboring proteobacterial denitrifiers are important players, and (iii) acidic soils like palsa peats represent reservoirs of diverse acid-tolerant denitrifiers associated with N2O fluxes. PMID:22660709

Palmer, Katharina

2012-01-01

382

Testing the potential of bacterial branched tetraether membrane lipids as temperature proxy in peat and immature coal deposits  

NASA Astrophysics Data System (ADS)

Branched glycerol dialkyl glycerol tetraether (brGDGT) membrane lipids occur ubiquitously in peat and soil. In soil, the degree of methylation and cyclisation of branched tetraethers (MBT index and CBT ratio, respectively) has shown to relate to both soil pH and annual mean air temperature (MAT). Using this relation, past annual MATs can be reconstructed by analysing brGDGTs in marine sediment records near large river outflows. More recently, the potential of this MBT/CBT proxy is also being explored in lakes. Despite being more abundant in peat than soils, however, the utility of the proxy has not yet been fully explored in peat records. Present day peat records generally extent back to the early Holocene, but if the MBT/CBT proxy were shown to be applicable in peat deposits, there is also potential to apply it to immature coal deposits like lignites, which could provide valuable snapshots of continental climate back to the early Cenozoic. Here results are presented of analyses of different peats in south eastern Canada, showing that the pH of peat along a nutrient gradient is rather well reflected by the CBT. Annual MAT reconstructions based on the MBT/CBT soil calibration, however, tend to overestimate measured MAT. This is also the case for peat analysed from the surface of Etang de la Gruère peat bog in the Swiss Jura Mountains. Along the 6m depth profile of this bog (~13ka), CBT-reconstructed pH is compared with in-situ measured pore water pH showing that the brGDGT composition does not reflect present-day in-situ conditions. Instead, it reflects a stratigraphic boundary between Carex and Sphagnum dominated peat at 4 m depth that is not present in the pore water profile, testifying to a 'fossil' nature of the brGDGTs down the peat bog. Analyses of three immature coals of the Argonne Premium Coal Series reveal that branched GDGTs are present in the most immature coal, the Beulah Zap lignite (Ro = 0.25%), and only just above detection limit in the Wyodak Anderson coal (Ro = 0.32%), both of about the same age (Late Palaeocene). In the more mature Illinois #6 coal (Ro = 0.46%), brGDGTs are completely absent. In the Denver Basin, a comparison is made between outcrop and drilled core samples of Palaeocene lignites. BrGDGTs are preserved in the core samples, although in low quantities compared to peat. Outcrop samples are clearly overprinted by modern soil derived brGDGTs, despite digging a meters deep trench, which shows the need to obtain fresh non-weathered samples by coring. Reconstructed annual MAT for both the Beulah Zap and the Denver Basin lignites are several degrees higher than estimates based on leaf margin and oxygen isotope analyses from the same sites. Both reconstructions do testify, nevertheless, to the warm continental conditions during the early Cenozoic of the central U.S.A.. Although further validation is required, potentially in the form of a specific peat calibration, these results do show potential for application of the MBT/CBT temperature proxy in peat and lignite deposits.

Weijers, J. W. H.; Steinmann, P.; Hopmans, E. C.; Basiliko, N.; Finkelstein, S. A.; Johnson, K. R.; Schouten, S.; Sinninghe Damsté, J. S.

2012-04-01

383

QTLs associated with root traits increase yield in upland rice when transferred through marker-assisted selection.  

PubMed

Altering root morphology of rice (Oryza sativa L.) cultivars could improve yields in drought-prone upland ecosystems. Marker-assisted backcross breeding was used to introgress four QTLs for root traits into an upland rice cultivar. The QTLs had previously been identified under experimental conditions in a different genetic background. The introgressed lines and the recurrent parent were grown for 6 years by resource-poor farmers in upland sites in Eastern India and yields recorded. In combination the QTLs significantly increased yield by 1 t ha(-1) under relatively favourable field conditions. In less favourable trials, the QTL effects were not detected due to greater heterogeneity in soil-water availability in very low yielding environments and consequent yield variability. Root studies under controlled conditions showed that lines with the introgressions had longer roots throughout tillering than the recurrent parent (14 cm longer 2 weeks after sowing). Therefore, both improved roots and increased yield can be attributed to the introgression of QTLs. This is the first demonstration that marker-assisted backcross breeding (MABC) to introgress multiple root QTLs identified under controlled conditions is an effective strategy to improve farmers' yields of upland rice. The strategy was used to breed a novel upland rice cultivar that has been released in India as Birsa Vikas Dhan 111. PMID:22968512

Steele, K A; Price, A H; Witcombe, J R; Shrestha, Roshi; Singh, B N; Gibbons, J M; Virk, D S

2013-01-01

384

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

385

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

386

Soil Property Effects on Wind Erosion of Organic Soils  

Technology Transfer Automated Retrieval System (TEKTRAN)

Histosols (also known as organic soils, mucks, or peats) are soils that are dominated by organic matter (>20%) in half or more of the upper 80 cm. Forty four states have a total of 21 million ha of histosols in the United States. These soils, when intensively cropped, are subject to wind erosion r...

387

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

388

Functioning of microbial complexes in aerated layers of a highmoor peat bog  

NASA Astrophysics Data System (ADS)

Monitoring was carried out using the luminescent-microscopic method of the abundance parameters of different groups of microorganisms in a monolith and in the mixed layers of a highmoor peat bog (oligotrophic residual-eutrophic peat soil) in a year-long model experiment. The increase of the aeration as a result of mixing of the layers enhanced the activity of the soil fungi. This was attested to by the following changes: the increase of the fungal mycelium length by 6 times and of the fungal biomass by 4 times and the double decrease of the fraction of spores in the fungal complex. The response of the fungal complex to mixing was different in the different layers of the peat bog. The maximal effect was observed in the T1 layer and the minimal one in the T2 layer. The emission of CO2 in the mixed samples was 1.5-2 times higher than that from the undisturbed peat samples. In contrast with the fungi, the bacteria and actinomycetes were not affected by the aeration of the highmoor layers.

Golovchenko, A. V.; Bogdanova, O. Yu.; Stepanov, A. L.; Polyanskaya, L. M.; Zvyagintsev, D. G.

2010-09-01

389

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

390

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