Geochemistry and geochemical differentiation on major elements in selected peat bog profiles (south-east of Poland)

Abstract

The geochemical differentiation of major elements in various peat bog profiles from Bieszczady Mountains Region (south-east of Poland) was compared to its botanical origin. Peat cores were taken from ombrotrophic, mesotrophic, and oligotrophic peatlands, which were developed in the stream valley of the River San. Twenty-four various peat samples were analysed for peat genus, degree of peat decomposition, ash content, total nitrogen, and total carbon content of hydrolytic matter as well as content of major elements: Na, K, Mg, Ca. The results show that the botanical composition of peat deposits is no reliable indication of their trophic status. The common feature of investigated Holocene peatlands is their valley localisation on the flood terrace. The specific character of local geommorpho8ogicml and hydrological condition caused that the bottom layer of all investigated bog profiles was made of wood peats (Piceaeti, Pineti, Alneti, and Saliceti peat). The geochemical investigations of stratigraphical profiles confirm that the presented peat bogs showed specific morphological separateness comparing to other raised bogs situated in mountains or lowlands     

Polycyclic aromatic hydrocarbons (PAHs) in peat and plants from selected peat‐bogs in the north‐east of Poland

The concentrations of polycyclic aromatic hydrocarbons (PAHs) were analyzed in samples of peat and of two plant species (Pinus sylvestris and Ledum palustre) overgrowing peat‐bogs in the north‐east of Poland. Peat samples were collected from different depths according to the stratigraphic profile of the peat bogs. The total concentrations of the 16 anthropogenic PAHs (15 from the US EPA list and benzo[e]pyrene) in all peat samples were between 70 and 439 ng g^—1. The concentration for the same compounds in pine needles (Pinus sylvestris) and Dutch Myrthe leaves (Ledum palustre) varied between 194 and 1039 ng g^—1. A noticeably high fluorene concentration in Dutch Myrthe leaves was found at some sites. In all peat samples 3‐ring compounds were predominant (55 to 319 ng g^—1). There were less 4‐ring PAHs (15 to 110 ng g^—1) and the least common PAHs were 5‐ring and 6‐ring compounds (0 to 81 ng g^—1 for both groups). In some peat samples, the perylene concentration largely exceeds of the total concentration of all the other PAHs investigated. The high content of perylene in bottom layers could result from the processes of perylene sorption from water during peat‐bog formation or from biogenic formation of perylene.     

Carbon decomposition processes in a peat from the Australian Alps

Carbon dioxide emissions and the mass loss of peat incubated in situ were measured in peat soils in the Australian Alps. The carbon chemistry of incubated peats was characterized using ¹³C nuclear magnetic resonance (NMR). In situ decomposition decreased as a function of increasing alkyl carbon content of the initial organic matter, providing direct evidence of the oft‐cited link between substrate quality and decomposition rates. More mass loss occurred in the bog peat samples than in the dried peat samples. However, at the peat surface, the amount of CO₂ emitted was not significantly different between bog peat and dried peat. Carbon inputs, and therefore the sink or source status, of these peats are yet to be quantified.     

Soil organic matter characterization of temperate peatland soil with FTIR‐spectroscopy: effects of mire type and drainage intensity

Peatlands are an important component of the global carbon cycle because they comprise huge amounts of terrestrial carbon (C). Different conditions during peat formation and secondary peat decomposition affect the quantity and composition of soil organic matter (SOM) in peats. There are few comparative studies on the chemical composition of SOM in temperate peatland soil. This study investigates compositional changes of SOM functional groups in peats and corresponding peat‐forming plants by Fourier transform infrared (FTIR) spectroscopy. Three plant samples and 29 peat samples were taken from seven temperate peatland sites with different genesis and land‐use intensity. Site‐specific differences, such as genesis of the peat, were found to be reflected in the FTIR spectra. In general, there was more variation in FTIR spectra in samples from fens than in those from bogs and peat‐forming plants. The samples from fens have a smaller C–H absorption band than those from bogs and plants, which reflects greater biochemical activity in the minerotrophic than ombrotrophic environments. In addition to peat genesis, drainage and secondary peat decomposition also affect SOM composition substantially. The larger amounts of aliphatic compounds in undrained peats could be explained by selective preservation caused by anaerobic conditions. With increasing drainage of the sites, there was a decrease in the C–H absorption that was accompanied by a relative increase in C=O absorption. These changes in absorption intensities reflect the enhanced aerobic decomposition and mineralization that accompanies drainage and land‐use intensity. However, the ‘degree of peat decomposition’, a diagnostic tool used in the field, is not reflected by OM composition determined by FTIR spectroscopy. Our results contribute to further understanding of changes in SOM composition during peat formation and processes of secondary decomposition caused by drainage.     

Biodegradation of humic substances by microscopic filamentous fungi: chromatographic and spectroscopic proxies

Purpose

The study of interactions between humic substances (HSs) and soil filamentous fungi is the key to understanding the sustainable soil functioning. The present work aims to examine the decomposition of HSs by filamentous dark-pigmented fungus Alternaria alternatа under the laboratory conditions and to determine the effect of easily assimilable organic carbon on this process. Analyzing such polydisperse substances like HSs by a complex integrated methodology makes it possible to explore the data on their decomposition by microorganisms.

Materials and methods

To achieve the aforementioned goals, we used chromatographic and spectroscopic approaches: low-pressure size-exclusion and hydrophobic interaction chromatography accompanied by absorption and fluorescence spectroscopy. To determine the effect cometabolism conditions produced on HS decomposition, two types of carbon substrates were added to the nutrient media: easily assimilable organic carbon (standard 0.3% or reduced 0.03% sucrose content) and hardly assimilable organic carbon (HSs), as well as their combinations. Five HS samples of different organic matter origin have been inspected: potassium humates (HPs) and humic acids (HAs) from coal, peat, and lignosulfonate. Correlation matrix and principal component analysis (PCA) were calculated for comprehensive data analysis.

Results and discussion

Transformations of the investigated HSs under fungal cultivation lead to the increase in the low molecular weight fraction, rise of hydrophilic fraction, enlargement of absorbance ratio A₂₅₀/A₃₆₅, shortening of the emission wavelength of the humic-type fluorescence, and growth in the fluorescence quantum yield measured with excitation at 355 nm. A positive correlation was observed between the accumulation of fungal biomass and the degree of HS decomposition. PCA analysis confirms that the difference in the results of HS decomposition largely depends on the sucrose content and the nature of HSs. We divided all the HS samples into four groups according to the degree of HS decomposition: original HS solutions, HPs altered using fungal cultivation at 0.03% sucrose, HAs after fungal cultivation at 0.03% sucrose, and finally, HSs (both HPs and HAs) after fungal cultivation at 0.3% sucrose.

Conclusions

In the laboratory experiments, we showed that (1) the isolated HAs were more effectively degraded than the parent HPs, and this process was more pronounced at a reduced sucrose content, and (2) the decomposition of stable organic compounds (HSs) was activated by the easily assimilable carbon sources (especially 0.3% sucrose) being present. We assume that it is the easily assimilable organic carbon that most likely triggers the HS degradation working as the priming effect in natural environments.

     

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

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

A survey of several soil physical characteristics of cultivated cranberry bog soils in North America

Abstract

Cranberries (Vaccinium macrocarpon Ait.) historically have been established on peat based soils and, in most cases, are treated every three to five years with a 1–4 cm layer of sand. A total of 46 soil samples from cranberry bogs in five states [Massachusetts (MA), New Jersey (NJ), Oregon (OR), Washington (WA), and Wisconsin (WI)] and one Canadian province [British Columbia (BC)] were collected and analyzed for bulk density, particle density, and percent organic carbon to assess the range of these characteristics which have resulted from management practices. Soil bulk densities ranged from 0.16 to 1.40 Mg/m³, particle densities from 0.71 to 2.45 Mg/m³, and organic carbon from 1.3 to 95. 2%. The wide ranges reflect the differences between non‐sanded and regularly sanded bogs. The low end of density and high end of organic C were found in the non‐sanded bogs, which were located in WA and BC. The bogs from the other areas had higher average bulk and particle density levels, approximately 1 and 1.7 Mg/m³, respectively.     

A comparison of peat properties in intact,afforested and restored raised and blanket bogs

Recognition of peatlands as a key natural store of terrestrial carbon has led to new initiatives to protect and restore them. Some afforested bogs are being clear-felled and restored (forest-to-bog restoration) to recover pre-afforestation ecosystem function. However, little is known about differences in the peat properties between intact, afforested and restored bogs. A stratified random sampling procedure was used to take 122 peat cores from three separate microforms associated with intact (hollows; hummocks; lawns), afforested and restored bogs (furrows; original surface; ridges) at two raised and two blanket bog locations in Scotland. Common physical and chemical peat properties at eight depths were measured in the laboratory. Differences in bulk density, moisture and carbon content between the afforested (mean = 0.103 g cm⁻³, 87.8% and 50.9%, respectively), intact (mean = 0.091 g cm⁻³, 90.3% and 51.3%, respectively) and restored bogs (mean = 0.095 g cm⁻³, 89.7% and 51.1%, respectively) were small despite their statistical significance. The pH was significantly lower in the afforested (mean = 4.26) and restored bogs (mean = 4.29) than the intact bogs (mean = 4.39), whereas electrical conductivity was significantly higher (mean: afforested = 34.2, restored = 38.0, intact = 25.3 μS cm⁻¹). While significant differences were found between treatments, effect sizes were mainly small, and greater differences in pH, electrical conductivity, specific yield and hydraulic conductivity existed between the different intact bogs. Therefore, interactions between geographic location and land management need to be considered when interpreting the impacts of land-use change on peatland properties and functioning.     

Presence and dispersal of infective Frankia in peat and meadow soils in Sweden

Summary Use of the N₂-fixing grey alder, Alnus incana (L.) Moench, as a short-rotation crop for energy production is currently being explored. To evaluate the need for inoculation of alders, the distribution of infective propagules of Frankia in the soil at potential sites for alder plantations was examined. Uninoculated grey alder seedlings were grown in three types of soil. Frequent nodulation was found in a meadow soil which had been free from actinorhizal plants for nearly 60 years, but the alder seedlings failed to nodulate in peat soil from two different bog sites. One of these bogs had been exploited for peat and the surface layer of the peat had been removed, so that the soil samples were taken from deep layers of the peat. At the other site, an area of cultivated peat, there were no infective propagules of Frankia in plots without alders; the infective Frankia was present in plots only where it had been introduced by inoculated alders. There was no detectable air-borne dispersal of Frankia. Instead, water movement might account for the dispersal of Frankia in peat. Although the apparent absence of Frankia in these peat soils necessitates inoculation of alder seedlings before planting out, this makes it possible to introduce and maintain Frankia strains with selected beneficial characteristics, since there is no competition from an indigenous Frankia flora.     

Bacterial diversity in peat bogs of karst depressions

Bacterial diversity in peat bogs of the karst origin was studied with the use of traditional inoculation methods and modern molecular techniques. Representatives of phylogenetic groups of Proteobacteria and Acidibacteria predominated among the domain of Bacteria. Aquaspirillum and Bacillus predominated in the saprotrophic bacterial complex. The amount of actinobacteria in the studied peat samples was higher than that in typical oligotrophic peat bogs.     

The structure of the microbial communities in low-moor and high-moor peat bogs of Tomsk oblast

The number, structure, and physical state of the microbial communities in high-moor and low-moor peat bogs were compared. Distinct differences in these characteristics were revealed. The microbial biomass in the high-moor peat exceeded that in the low-moor peat by 2–9 times. Fungi predominated in the high-moor peat, whereas bacteria were the dominant microorganisms in the low-moor peat. The micromycetal complexes of the high-moor peat were characterized by a high portion of dark-colored representatives; the complexes of the low-moor peat were dominated by fast-growing fungi. The species of the Penicillum genus were dominant in the high-moor peat; the species of Trichoderma were abundant in the low-moor peat. In the former, the bacteria were distinguished as minor components; in the latter, they predominated in the saprotrophic bacterial complex. In the high-moor peat, the microorganisms were represented by bacilli, while, in the low-moor peat, by cytophages, myxobacteria, and actinobacteria. The different physiological states of the bacteria in the studied objects reflecting the duration of the lag phase and the readiness of the metabolic system to consume different substrates were demonstrated for the first time. The relationships between the trophic characteristics of bacterial habitats and the capacity of the bacteria to consume substrates were established.     

Detrimental effects of peat mining on amphibian abundance and species richness in bogs

Peat bogs of eastern North America are increasingly being mined for peat, which results in the extensive draining of these systems. First, I quantified the effects of peat mining on amphibian species richness and abundance in bog remnants adjacent to mining activity and unmined bogs. I then investigated amphibian occurrence patterns in bog remnants relative to the distance to the mined edge, after accounting for microhabitat and distance to landscape elements. The response of amphibians to peat mining varied across taxa. For instance, amphibian species richness, total amphibian captures (all spp. combined), as well as those of green frogs (Rana clamitans) were greater in unmined bogs than in bog remnants. Wood frogs (Rana sylvatica) were most abundant in unmined bogs in areas far from bog ponds, as well as in unmined bogs in areas near shrub patches. After accounting for microhabitat and landscape variables, American toads (Bufo americanus) in bog remnants were most abundant close to mined edges, whereas the other species did not respond to the proximity of mined edges. Peat mining negatively impacts amphibians occurring in bog remnants. The response of amphibians to peat mining is similar to the one of birds and plants, but differs with small mammals. Maintaining a complex mosaic of bog ponds, shrub and forest patches might help mitigate peat mining effects on amphibian patterns of abundance.     

Torfeigenschaften und ungesättigte hydraulische Leitfähigkeit von Moorböden

Peat properties and unsaturated hydraulic conductivity of peat soils . Drainage of organic soils is closely connected with water supply of plants by the capillary fringe of the groundwater. Unsaturated flow of water was measured by the double-membrane apparatus described by Vetterlein, which was modified for experiments with undisturbed peat samples. The influence of decomposition, nature of peat, ash content, bulk density (consolidation) and flux direction on unsaturated flow of water in peat soils was determined. The correlation to unsaturated water conductivity decreased in the sequence: decomposition, flux direction, ash content, bulk density. A dependence on bulk density exists only below pF 2.     

The influence of the bog water level on the transformation of sphagnum mosses in peat soils of oligotrophic bogs

Quantitative estimates of the rate of transformation of moss residues of two species (Sphagnum angustifolium and Sphagnum fuscum) in the peat soils (Histosols) were obtained for two oligotrophic bogs with different hydrological conditions in the southern taiga of Western Siberia. The coefficients of decomposition rate (k) significantly differed for the studied species; the decomposition of Sphagnum fuscum proceeded much slower. The most intense decomposition was observed in the first year of transformation (k = 0.06 and 0.16–0.66 for Sph. fuscum and Sph. angustifolium, respectively); then, the rate of moss decomposition decreased. Despite the great amount of fungal mass in the moss residues (exceeding the bacterial biomass by 3–10 times), the rate of the initial decomposition was very low. The hydrological conditions affected the intensity of this process—in the peat of the Kirsanovskoe bog with the low level of bog water, losses of the mass of sphagnum moss were 1.1–1.6 times greater as compared to those in the Bakcharskoe bog. For Sph. angustifolium, the level of bog water was more important than for Sphagnum fuscum, whereas for Sphagnum fuscum, the composition of organic matter played a decisive role in the rate of decomposition of moss residues. The activity of the microflora also depended on the level of bog water, which was manifested in a greater abundance of bacteria in the peat of the Kirsanovskoe bog.     

Water Repellence of Cultivated Organic Soils

Abstract

A range of cultivated organic soils was studied with respect to water repellence. All soils were wettable above a water content of approximately 30-50 % (v/v). Below this critical content, most soils showed a varying degree of water repellence. Well decomposed peat had lower infiltration rates than moderately decomposed peat. Lightly crushing the peat soil before measurement increased the infiltration rate compared with an undisturbed soil sample. In tests with aqueous ethanol of different molarity, peat soils showed greater repellence than gyttja soils. All moss peat layers were extremely water repellent and fen peats slightly less repellent. Water repellence did not occur on gyttja clay and marl gyttja.     

The importance of episodic ebullition methane losses from three peatland microhabitats: a controlled‐environment study

Ebullition and episodic ebullition in particular, may be an important pathway for methane (CH₄) losses from northern peatlands. We quantified the importance of episodic ebullition using controlled environment laboratory incubations of samples of near‐surface bog peat, focusing on how ebullition can be measured effectively and assessing the variation in CH₄ losses between microhabitats and seasons. The peat samples were collected from hollow and lawn microhabitats at two raised bogs: Longbridgemuir, southwest Scotland, and Cors Fochno, west Wales. We found that CH₄ fluxes excluding episodic ebullition differed between peatland microhabitats but not between summer and early autumn conditions. Conversely, episodic ebullition did not differ between microhabitat types but virtually stopped after the onset of early autumn conditions. Most strikingly, episodic ebullition was less than 3.3% of total CH₄ fluxes, and was therefore an insignificant mechanism of CH₄ loss from our peat samples.     

The microbial diversity and structure in peatland forest in Indonesia

The microbial community structure and function under forest in tropical peatlands are poorly understood. In this study, we investigated the microbial community structure and diversity in natural peat swamp forest soil, disturbed peat soil and mineral soil in Central Kalimantan, Indonesia, using 454 pyrosequencing. The results showed that the natural peat soil had the greatest fungal species richness (Chao1), which was significantly (p < .05) larger than that in the other two soils. Community structure of both fungi and bacteria in natural peat soil differed significantly from that in the disturbed peat soil (p = .039 and p = .045, respectively). Ascomycota (40.5%) was the most abundant phylum across the three soils followed by Basidiomycota (18.8%), Zygomycota (<0.1%) and Glomeromycota (<0.1%). The linear discriminant analysis with effect size (LEfSe) showed that Ascomycota (p < .05) and genus Gliocephalotrichum (p < .05) dominated in natural peat soil. Functionally, pathotrophs were more abundant in disturbed peat soil (p < .05). Proteobacteria (43.8%) were the most abundant phylum followed by Acidobacteria (32.6%), Actinobacteria (9.8%), Planctomycetes (1.7%). Methylocystis, Telmatospirillum, Syntrophobacter, Sorangium and Opitutus were the more abundant genera in disturbed peat soil, whereas Nevskia and Schlesneria were more abundant in mineral soil and natural peat soil, respectively. The natural peat forest soil supported a more diverse microbiology; however, the land use of such a soil can change its microbial community structure. The results provide evidence that the disturbance of tropical peat land could lead to the introduction and spread of a large number of fungal diseases     

Changes in the chemical composition of the organic carbon in Spartina alterniflora litter during decomposition in saltmarsh sediments

Purpose

In this study, 1-year decomposition experiments were conducted to measure the litter carbon decomposition dynamics in saltmarsh and to determine the changes in the chemical structure of litter carbon during the litter decomposition process.

Methods

Litterbags containing a mixture of Spartina alterniflora litter and burned sediment were buried at four S. alterniflora saltmarshes and one S. alterniflora–Suaeda salsa co-existing saltmarsh. The contents of total organic carbon (TOC) and recalcitrant carbon (RC) were determined by a Sercon Integra CN isotope ratio mass spectrometer, while the content of labile carbon (LC) was estimated by calculation. ¹³C nuclear magnetic resonance (NMR) spectroscopy was conducted to characterise the chemical structures of the organic carbon compounds in the S. alterniflora litter during decomposition. Solid-state ¹³C–CPMAS-NMR spectra were obtained using an AVANCE III 400 MHz (Bruker) spectrometer.

Results

The results indicated that more RC than LC remained in the litterbag during decomposition. The organic carbon content of the S. alterniflora litter was largely composed of alcoxyl-C compounds (78.9%), the decomposition products of which dominated the litter organic carbon fractions, including the TOC, RC, and LC. In contrast, alkyl-C, aromatic-C, and carboxyl-C products contributed mostly to RC. Differences in the negative correlations between the litter carbon fractions and alkyl-C, aromatic-C, and carboxyl-C were found among the developing saltmarshes. Humus generated by the S. alterniflora litter was mainly composed of macromolecular organic compounds containing functional groups such as methyl, methylene, methine, methoxyl, aromatic rings, phenolic hydroxyl, and carboxyl.

Conclusions

During decomposition, the organic carbon in the S. alterniflora litter was found to be dominated by O-alkyl-C, followed by aromatic-C, alkyl-C, and carboxyl-C. O-alkyl-C plays a major role in the LC proportion of organic carbon, while aromatic-C, alkyl-C, and carboxyl-C contribute more to the RC proportion. Alkyl-C was found to be more easily decomposed than aromatic-C in the S. alterniflora litter. During litter decomposition, the molecular structure complexity, humification degree, and decomposition degree of organic carbon exhibited seasonal variations. In the 3-year saltmarsh, more decomposition of the organic carbon in the S. alterniflora litter was observed as compared to other sites.

     

Site of nitrogen accumulation in tulip (Tulipa gesneriana L.) roots during winter

Abstract

Plants (60 species in 37 genera, 27 families) grown on granite weathered soils of temperate natural forest in central Japan were sampled and analyzed for Fe, Mn and Cu. Soil samples coIlceted from the site of plant stands were also analyzed. Results showed that considerable difference existed amons plant species with less variations amons plant samples of the same plant species. Similar responses were frequently found among plant species in the same genus and sometimes in the same family. Variations due to soU also occurred but to a lesser degree. Pe, Mn and Cu were generaIly low in coniferous trees. On the other hand Acantiropanax sciadophylloides accumulated higher amount of Mn in the leaves (4.6 × 10³ ppm, dry matter basis) which is about 180 times more than that of low content species. Other Mn accumulating species were found in Anacardiaceae and Aceraceae. Cryptomeria japonica was the lowest in Mn content (26 ppm). Mean concentration ratio for Mn was 113. Cu was found to be slightly rich in scattering species including Lastrea japonica, Magnolia salleifolia, Acer mono var. connivens and Callicarpa japonica. Mean concentration ratio for Cu was 17.     

Utilization Potential of Peats – a Study on Peat Biodegradability Determined by Respirometric Method

The biodegradation of different peat types was studied with a manometric respirometric test. Compaction peat and sphagnum peat samples were analysed, and the effect of peat pH on biodegradation behaviour was evaluated. Only minor (BOD/ThOD?<?0.4%) biodegradation was observed with compaction peat samples, and the stable state, in which biodegradation stopped, was achieved during a two month period. As expected, sphagnum peat samples with a lower decomposition rate degraded more than compaction peat samples. Alkalinity (pH between ca. 4–9) of the peat was noticed to reduce the degree of biodegradation and accelerate the achievement of the stable state.