Peat Types Research Articles

Generating multi-proxy Holocene palaeoenvironmental records from blanket peatlands

Ombrotrophic peatlands have provided important archives for understanding Holocene palaeoenvironmental change. However, records are predominantly from raised bogs due to potential issues regarding preservation of proxy indicators, record length and low temporal resolution in other peat types including blanket bogs. By carrying out peat depth and stratigraphy surveys we demonstrate how blanket peatlands can provide archives capable of providing records that are not reliant on single proxies, as has been often the case in the past, and can provide good resolution records. A record containing humification, testate amoebae and plant macrofossils was derived for the last 3000 years with accumulation rates as high as 8yrscm−1 providing favourable temporal resolution, particularly over the last 1500 years. Major changes in proxy indicators reflecting potential changes in water-table depth were often coherent with changes in climate. Human activity also had a major impact on the peatland throughout the record especially in the last 100 years where the influence of wildfire and managed burning, together with an effect of atmospheric pollution, fundamentally changed the state of the peatland.

Compressibility behaviour of peat reinforced with precast stabilized peat columns and FEM analysis

Researches have been done to discover ways to strengthen peat soil deposits. In this model study, fibrous peat that is the most compressible types of peat has been reinforced with precast peat columns stabilized with ordinary Portland cement and polypropylene fibres. Rowe cell consolidation tests as well as plate load tests (PLTs) were conducted on various types of test samples to evaluate the strength and deformation of untreated peat and peat reinforced by various types of columns. PLTs were conducted in a specially designed and fabricated circular steel test tank. The compression index (Cc) and recompression index (Cr) of fibrous peat samples reduced considerably upon use of precast columns. Also, PLT results confirmed the results obtained from Rowe cell tests. Use of polypropylene fibres added to cement further decreased (Cc) and (Cr) and increased load bearing capacity of untreated peat. Finite element method (FEM) using Plaxis 3D was carried out to evaluate the stress distributions along various types of tested samples and also, to compare the deformations obtained from FEM analysis with the actual maximum deformations found from PLTs. FEM results indicate that most of the induced stresses are taken on the upper portion of tested samples and reach their maximum values below the loading plate. Also, a close agreement was found between actual deformation values obtained from PLTs and values resulted from FEM analysis for various types of tested samples.

Carbon Mineralization in Peatlands: Does the Soil Microbial Community Composition Matter?

Peat from four geographically separated peatlands (up to 1,500 km apart) with distinct vegetation across North America was sterilized and inoculated with microbial consortia from either the home site or from the other sites. This reciprocal inoculation microcosm experiment examined how different microbial communities adapted to various peat substrates and how this in turn influenced C-mineralization patterns. The experimental approach allows distinctions to be made as to whether microbial community structure, peat properties, or imposed environmental conditions are primary drivers of peat C mineralization. Two additional inocula collected from other freshwater environments (industrially polluted harbor and lake sediments) were also added to each peat type to investigate the response of clearly disparate microbial communities. We hypothesized that the peat properties, such as substrate quality and physical structure, would dictate microbial community composition and activity, thus inoculations from different sites into the same peat soil would lead to the establishment of very similar microbial communities both phylogenetically and functionally. Post-incubation, the bacterial communities in each site converged towards a similar community regardless of the inoculum source, with the exception of peat inoculated with polluted harbor sediment. Inoculum type had no effect on C mineralization rates compared with controls, except for the two disparate inocula, which had lower rates in all peat types. Variation in microbial community structure measured as nonmetric multidimensional scaling axes scores or richness did not correlate significantly with microbial activity. Overall, these findings suggest that abiotic variables (e.g., pH, aeration, moisture content, and temperature) are the dominant control on peatland microbial activity and community composition, and in natural peatlands the microbial community can quickly adapt to future environmental change.

Preliminary investigation of mineralogy and chemistry of peats from the Kietrz site, southern Poland

Abstract Peat bog deposits provide a very important record of past environmental conditions, preserving biotic and abiotic processes that occurred in the vicinity of the bog. In this study, we examined three peat bog profiles from Kietrz, located in the micro-region of the Głubczycki Plateau, southern Poland. The objective of this study was to determine the type of peat occurring in this area, through examination of its mineral composition, and evaluation of the total carbon and total sulphur content. In addition, we measured peat reaction (pH) and identified floral and faunal components occurring within the peat deposits. The peat comprises primarily of fragments of fossilized plant and mollusk remains, as well as minerals (calcium sulphates, calcium carbonates, and pyrites). Additionally, an assemblage of iron oxides/hydroxides, Kfeldspar, apatite, zircon, and quartz grains was identified. A neutral and/or light alkalinity was recorded for the peat deposits, but an increase in acidity (pH) with increasing depth through each peat profile was also recorded. We observed a positive correlation between the pH and chemical composition of deposits, where a significant presence of calcite is associated with higher reaction (higher pH), whilst a lower pH is characteristic for sediments where carbonates are rare. The recognized species of mollusks are typical of shallow, fresh-water stagnant reservoirs with a high fluctuation of water level.

Natural peat bog remnants promote distinct spider assemblages and habitat specific traits

Peat bogs are very sensitive and highly endangered ecosystems. They were once typical landscape elements in northern Germany, but today only a few remnants exist. On-going habitat degradation has alarming adverse effects on biodiversity, and, from a conservation viewpoint, it is imperative to evaluate the current ecological quality of the remaining peat bog remnants to assess the intensity of degradation and to suggest reasonable management strategies. In 2007, spiders were sampled in 23 study sites representing typical peat bog habitat types in the northern parts of Westphalia (NW Germany). In all, 214 species from 18,413 adult individuals have been collected. Multivariate analyses showed that different peat bog successional stages harbour distinct spider assemblages with succession being the main driver for species separation. Pardosa sphagnicola, Pirata piscatorius and P. uliginosus can be considered as flagship species for near-natural or natural peat bogs. Trait analyses showed that habitat specialisation for high moisture is negatively affected by succession. Peat bogs are now only small remnants, but, nevertheless, they have a high conservation value as they still harbour a distinct species assemblage and specialised species.

Effects of substrate and ectomycorrhizal inoculation on the development of two-years-old container-grown Norway spruce (Picea abies Karst.) seedlings

Abstract: The objective of this study was to test the effects of selected peat growth substrates (Agro CS, Gramoflor and Durpeta) and inoculation with commercial ectomycorrhizal inocula (Ectovit and Mycorrhizaroots) on growth, ectomycorrhiza formation, needle nutrients concentration and several physiological parameters of two-years-old containerized Norway spruce seedlings cultivated under standard nursery conditions. The selected substrates differed in origin, composition and nutrient content: Agro CS and Gramoflor were mixtures of various peat types and components with added nutrients, while Durpeta was non-enriched pure peat. Growth parameters of seedlings cultivated in enriched substrates were significantly higher than those grown on the non-enriched substrate. Significant interactions were found between substrate and inoculation treatments. Inoculation with Ectovit stimulated seedling growth in non-enriched substrate but had no effect on seedling parameters in the enriched substrates, and a negative effect on aboveground biomass in Gramoflor. Mycorrhizaroots inoculum significantly decreased shoot to root dry weight ratio, but had no other effect on seedling development. ECM colonization rate of seedlings ranged from 73 to 80%, with no significant effects of the ECM inoculum or growth substrate. DNA analysis revealed a low species diversity of ECM fungi on seedling roots, with a pronounced dominance of the soil-borne ECM species Thelephora terrestris Fr. Chemical analysis of needles and measurement of chlorophyll a fluorescence showed similar trends as seedling growth. Values of chlorophyll a fluorescence parameters and needle N, P, K, Ca and Mg concentrations were higher in both enriched substrates. Ectovit increased (though not significantly) chlorophyll a fluorescence in needles as compared to Mycorrhizaroots- and non-inoculated seedlings, as well as nutrient-uptake (mainly K) in the non-enriched substrate. Our results suggest the importance of the origin and composition of peat-based substrates on the development of container-grown Norway spruce seedlings, while the observed positive effect of the commercial ECM inoculum Ectovit was more probably caused by its physical and chemical properties rather than by its efficiency in promoting ECM fungi symbiosis. The enriched substrates tested appear to be suitable for production of spruce seedlings of acceptable size for outplanting within two growing seasons.

Multi‐species competition experiments with peatland bryophytes

AbstractQuestionSpecies interactions are one of the processes determining composition of plant communities. We used the community density series method to study competition in a multi‐species community of bryophytes common in calcareous fens. The succession of mires is driven by Sphagnum species, which are supposedly superior to brown mosses in competition for resources and space, but little is known about the environmental conditions in which brown mosses can prevail when subject to neighbour interactions. How are interactions among peatland bryophytes affected by the environment?LocationField and garden experiments near Uppsala in mid‐eastern Sweden.MethodsTo examine the effects of environment on competition and competitive hierarchies we assembled multi‐species communities of ten bryophyte species from shoot fragments (brown mosses and Sphagnum species) at two densities and grew them on three types of peat (representing poor, intermediate and rich fens) under dry or wet conditions in a garden experiment and along pH and wetness gradients in the field.ResultsA multivariate analysis of the garden experiment showed that community composition was affected by peat type and wetness and their interactions. The brown mosses performed better in wet and rich fens, the Sphagnum species in drier and poorer fens. The Sphagnum species were overall the best competitors.ConclusionsThe experiments demonstrated contrasting responses of brown mosses and Sphagnum to properties of the microhabitat. Sphagnum species were generally less affected by competition than the brown mosses. Sphagnum species were competitive in habitats typically dominated by brown mosses and even responded positively to crowding. This can explain why Sphagnum can invade calcareous fens. In contrast, brown mosses performed poorly in habitats more typical of Sphagnum species.

Impact of Heat Treatment on Humic Acid Elemental Content and Thermal Stability

The article examines the impact of thermal peat modification on the elemental content and properties of humic acids. It has been revealed that preliminary heat treatment of different peat types characterized by various decomposition degrees causes the changes in elemental content; precisely it leads to the increase in macromolecule benzoid degree and subsequent enhancement of its thermal stability.

Peat Characteristics and its Impact on Oil Palm Yield

The yield potential of oil palm planted on peat land has always been a controversial subject. Most past soil research on oil palm yield on peat land was mainly based on the depth and drainability. Little attention was given to the impact of peat characteristics on oil palm from a yield perspective. This study tests the hypothesis that physical soil properties such as peat maturity, presence of wood, depth and nature of underlying substratum affects oil palm yield. The initial study involved the evaluation of soil mapping units on estates in Sibu, Sarawak, East Malaysia and from this exercise of four organic soil mapping units which reflected the different characteristics of soils were selected. Data on peat depth, presence and absence of decomposed and undecomposed wood, nature of underlying substratum and peat maturity (fibric, sapric and hemic) were collected, analyzed and interpreted. Comparisons were also made on mineral soil found at the same location. Yield data were analyzed from primary sources from oil palm estates. Results show that different types of peat have significant effect on oil palm yield ranging between 9.47 - 22.92mt/ha. Peat maturity has the most significant effect on yield. Sapric peat showed a yield range of 19.48-22.92mt/ha as compared to hemic peat ranging between 9.47- 13.37mt/ha. Palms planted on soils with sandy substratum showed significant 18 -142% higher yields compared to those over marine clay as underlying material. No significant differences were observed in the yields due to the different depths and presence/absence of wood as a single factor. However, a combined factor of peat maturity and presence with nature of wood do have significant impact on yield.The study further confirms that sandy spodosol like Bako series perform 30 - 40.44% lower yields compared to peat soils such as Telong and Naman series.The results are important as peat areas with specific physical soil properties and showing poor yields can been left for conservation prior to development. Thus selective development based on semi detailed soil surveys producing maps giving peat characteristics and its impact to oil palm yield is possible. However, a more balanced view and future research should be emphasised to other issues such as cost of development of peatland compared to the price of crude palm oil in the world market, biodiversity, social issues, Green House Gas (GHG) emissions and potentials of improving productivity on existing organic and mineral soils need to be further explored. The study therefore challenges the existing believe that peat depth is very significant in determining oil palm yield. The study also enhances the need for soil surveys for land use decisions and wise use of peatlands. Further research is recommended to narrow the knowledge gaps and uncertainties on peatland.

Spatial variability of selected physicochemical parameters within peat deposits in small valley mire: a geostatistical approach

Abstract Geostatistical methods for 2D and 3D modelling spatial variability of selected physicochemical properties of biogenic sediments were applied to a small valley mire in order to identify the processes that lead to the formation of various types of peat. A sequential Gaussian simulation was performed to reproduce the statistical distribution of the input data (pH and organic matter) and their semivariances, as well as to honouring of data values, yielding more ‘realistic’ models that show microscale spatial variability, despite the fact that the input sample cores were sparsely distributed in the X-Y space of the study area. The stratigraphy of peat deposits in the Ldzań mire shows a record of long-term evolution of water conditions, which is associated with the variability in water supply over time. Ldzań is a fen (a rheotrophic mire) with a through-flow of groundwater. Additionally, the vicinity of the Grabia River is marked by seasonal inundations of the southwest part of the mire and increased participation of mineral matter in the peat. In turn, the upper peat layers of some of the central part of Ldzań mire are rather spongy, and these peat-forming phytocoenoses probably formed during permanent waterlogging.

Downwash of atmospherically deposited trace metals in peat and the influence of rainfall intensity: An experimental test

Accumulation records of pollutant metals in peat have been frequently used to reconstruct past atmospheric deposition rates. While there is good support for peat as a record of relative changes in metal deposition over time, questions remain whether peat archives represent a quantitative or a qualitative record. Several processes can potentially influence the quantitative record of which downwashing is particularly pertinent as it would have a direct influence on how and where atmospherically deposited metals are accumulated in peat. The aim of our study was two-fold: first, to compare and contrast the retention of dissolved Pb, Cu, Zn and Ni in peat cores; and second, to test the influence of different precipitation intensities on the potential downwashing of metals. We applied four ‘rainfall’ treatments to 13 peat cores over a 3-week period, including both daily (2 or 5.3mmday−1) and event-based additions (37mmday−1, added over 1h or over a 10h rain event). Two main trends were apparent: 1) there was a difference in retention of the added dissolved metals in the surface layer (0–2cm): 21–85% for Pb, 18–63% for Cu, 10–25% for Zn and 10–20% for Ni. 2) For all metals and both peat types (sphagnum lawn and fen), the addition treatments resulted in different downwashing depths, i.e., as the precipitation-addition increased so did the depth at which added metals could be detected. Although the largest fraction of Pb and Cu was retained in the surface layer and the remainder effectively immobilized in the upper peat (≤10cm), there was a smearing effect on the overall retention, where precipitation intensity exerts an influence on the vertical distribution of added trace metals. These results indicate that the relative position of a deposition signal in peat records would be preserved, but it would be quantitatively attenuated.

The Use of Principle Component Analysis in Type Classification of Air-dry Peat

The use of principle component analysis (PCA) in the variant of projection on latent values with discriminant analysis (PLS-DA) in type classification of Siberian region air-dry peat by a set of properties is presented. A statistical analysis in principle component space by PCA of different physico-chemical properties of peat such as component composition, concentration of paramagnetic centers and IR-spectra is presented and shows a developed PLS- DA classification model allows estimating peat type by a set of physico-chemical properties with minimum prediction errors.

Impacts of climate and vegetation change on carbon accumulation in a south-central Alaskan peatland assessed with novel organic geochemical techniques

To constrain the effect of climate and peatland type on carbon accumulation, we reconstructed these parameters from a Holocene-length core of a Sphagnum-dominated peatland near Cordova, AK, USA. We determined peat type using a combination of peat texture and density, macrofossils, distributions of leaf-wax biomarkers, and soil pH reconstructions based on distributions of branched glycerol dialkyl glycerol tetraether lipids (brGDGTs). We produced an independent record of hydroclimate and temperature change using hydrogen isotope ratios of leaf-wax biomarkers and distributions of brGDGTs. Carbon accumulation rates were constrained with 14 AMS 14C dates from identified macrofossils and ash-free bulk density. In the early Holocene, the site was a shallow pond with evidence for emergent macrophytes, Sphagnum, and algae growing in a warm, moist climate. At 9.2 kyr (1 kyr = 1000 cal. yr BP), the site became a Sphagnum-dominated bog. Under mid-Holocene warm, evaporative climate conditions, the site became sedge-dominated. As climate cooled and effective precipitation increased, Sphagnum was able to gain dominance abruptly at ~3.5 kyr. Large changes in the vegetation assemblage and hydrology and climate are contemporaneous with significant changes in the rate of carbon accumulation. Carbon accumulated most rapidly when Sphagnum dominated and effective moisture was high and most slowly when sedges were dominant and conditions were warmer and drier. Estimates of future climate change indicate warmer, more evaporative conditions that, in the past, favored a sedge-dominated environment, suggesting that this peatland and those similar can contribute to a positive feedback to warming by transitioning to less efficient carbon sinks.

EFFECT OF DIFFERENT SUBSTRATES ON ROOTING AND FLOWER DEVELOPMENT OF PRIMARY AND TERTIARY RUNNERS OF STRAWBERRY TRAY PLANTS CULTOVAR 'ELSANTA'

An experiment was set up to investigate the effects of different substrates on the growth and yield of plants derived from primary and tertiary runners. ‘Super elite’ strawberry mother plants cultivar ‘Elsanta’ were planted in February 2010 into peat modules. Primary and tertiary runners from the mother plants were harvested after five months. They were subsequently planted into strawberry propagation trays with five different substrates blends. These consisted of two peat types (clonbrin & Bord na MA³na), coir, composted green waste (CGW) and a peat and CGW mix. There was a highly significant difference in dry root biomass and number of flowers per plant between treatments. The highest dry root biomass was obtained from primary runners rooted in clonbrin peat (3.41 g) and the coir-clonbrin peat mix (3.31 g). The lowest were obtained from tertiary runners rooted in CGW-clonbrin peat mix (1.83 g) and the CGW (1.91 g). The highest numbers of flowers per plant were from primary runners grown in the Bord na MA³na peat (54.1), CGW-clonbrin peat mix (50.2) and the coir-clonbrin peat mix (50). The lowest flower counts were obtained from tertiary runners grown in the coir-clonbrin peat mix (34.6) and primary runners grown in the CGW (34.7).

A database and synthesis of northern peatland soil properties and Holocene carbon and nitrogen accumulation

Here, we present results from the most comprehensive compilation of Holocene peat soil properties with associated carbon and nitrogen accumulation rates for northern peatlands. Our database consists of 268 peat cores from 215 sites located north of 45°N. It encompasses regions within which peat carbon data have only recently become available, such as the West Siberia Lowlands, the Hudson Bay Lowlands, Kamchatka in Far East Russia, and the Tibetan Plateau. For all northern peatlands, carbon content in organic matter was estimated at 42 ± 3% (standard deviation) for Sphagnum peat, 51 ± 2% for non- Sphagnum peat, and at 49 ± 2% overall. Dry bulk density averaged 0.12 ± 0.07 g/cm3, organic matter bulk density averaged 0.11 ± 0.05 g/cm3, and total carbon content in peat averaged 47 ± 6%. In general, large differences were found between Sphagnum and non- Sphagnum peat types in terms of peat properties. Time-weighted peat carbon accumulation rates averaged 23 ± 2 (standard error of mean) g C/m2/yr during the Holocene on the basis of 151 peat cores from 127 sites, with the highest rates of carbon accumulation (25–28 g C/m2/yr) recorded during the early Holocene when the climate was warmer than the present. Furthermore, we estimate the northern peatland carbon and nitrogen pools at 436 and 10 gigatons, respectively. The database is publicly available at https://peatlands.lehigh.edu .

Accumulation of chemical elements in the raised peatbogs of the subtaiga Trans-Urals in the Holocene

The results of studying the variability of the geochemical parameters of the layers of the Sartamskii upland peatbog in the south of Tyumen oblast based on the radiocarbon time scale are given. Four basic types of peat and stages of peat deposits formation in the Holocene are distinguished: the organomineral layer of the sediments in a paleolake (up to 5065 ± 60 years ago), the low moor layer (4300–4900 years ago), the transitional layer (3100–4300 years ago), and the high moor peat (250–3100 years ago). The upper peat layer (last 200–300 years) significantly differs from its main portion; in particular, it is characterized by an increased ash content and the accumulation of a number of elements. The relationship between the various characteristics of the deposit is analyzed using principal component analysis, and the conditions of the formation of the peat deposit in different time periods are estimated, including the climatic conditions (in relative units). The anthropogenic signal of the accumulation of some elements in wetland systems is identified.

Computational smoldering combustion: Predicting the roles of moisture and inert contents in peat wildfires

Smoldering combustion is the slow, low-temperature, flameless burning of porous fuels and the most persistent type of combustion. It is the driving phenomenon of wildfires in peatlands, like those causing haze episodes in Southeast Asia and Northeast Europe, but is poorly understood. In this work, we develop a comprehensive 1-D model of a reactive porous media, using the open-source code Gpyro, to investigate smoldering combustion of natural fuels with an emphasis on the roles of the moisture and inert contents. The model solves the species, momentum, and energy conservation equations and includes heterogeneous chemical reactions. A previously developed 5-step reaction scheme for peat, including evaporation of water, is adopted to describe the drying, thermal and oxidative degradation during the smoldering combustion. The model predicts the transient temperature, species, and reaction profiles during ignition, spread, and extinction. The predicted smoldering thresholds related to the critical moisture and inorganic contents for ignition show a good agreement with the experimental results in the literature for a wide range of peat types and organic soils. The influences of the kinetic parameters, physical properties, and ignition protocol are investigated. This is the first time that a physics-based model of smoldering peat fires is developed, thus helping to understand this important natural and widespread phenomenon.

Saturated hydraulic conductivity in Sphagnum‐dominated peatlands: do microforms matter?

AbstractWithin peatland ecosystems, small deviations in surface elevation result in microforms that differ in depth to water table, plant type and rate of biogeochemical cycling, possibly leading to differences in peat physical and hydrological properties that could feed back to the whole ecosystem hydrological and biogeochemical function. However, hydrological parameters for peatland microforms have not been quantified. This study determined bulk density, pore size distribution and saturated hydraulic conductivity (Ksat) at hummocks and hollows of four, Sphagnum‐dominated Canadian peatlands. Study sites included both a bog and poor fen in each of Alberta and Quebec allowing for investigation of differences in peat hydrophysical properties between microforms across a range of Sphagnum‐dominated peatlands. Hydraulic conductivity was determined in the laboratory on peat from the surface (0.03–0.08 m) and the saturated zone (0.20 m below the local water table position). Peatland type, climate region, microform and depth of peat were all significant descriptors of variation in Ksat. Deeper peat was less conductive than surface peat. Hummocks generally had higher Ksat than hollows at both surface and saturated zones, although differences between microforms varied between sites. Differences in Ksat between samples were correlated with bulk density, von Post humification and macroporosity. These results indicate that there are microtopographical differences in peat hydrophysical properties; however, the strong decline in Ksat with depth indicates that differences in the local water table, resulting in a change in depth of water flow, is likely a stronger control on local Ksat than microform type. Copyright © 2014 John Wiley & Sons, Ltd.

Evaluation of the Adsorption of Mono- and Polytungstates onto Different Types of Clay Minerals and Pahokee Peat

Detailed knowledge about the fate and transport of tungsten in soils is critical to understanding and effectively addressing tungsten behavior in the environment. Recent studies have shown that tungsten anions may polymerize (depending upon concentration, pH, and aquatic geochemistry) in aquatic and soil systems. However, to date, of all soluble tungstate species only monotungstates have been scrutinized to a fair extent in adsorption studies. There is a lack of information evaluating adsorption mechanisms of mono- and polytungstates onto clay minerals. The objective of this work is to investigate the adsorption behavior of monotungstates (sodium tungstate, Na2WO4) and polytungstates (sodium metatungstate, 3Na2WO4·9WO3) onto different types of clay minerals (montmorillonite, kaolinite, illite) and an organic adsorbent (Pahokee peat). Batch equilibrium experiments as a function of concentration (adsorption isotherms) and pH (adsorption envelopes) were performed to provide information about mono- and polytungstate adsorption onto clays and Pahokee peat. Adsorption equilibrium data for mono- and polytungstates onto different types of clay minerals and Pahokee peat were modeled with Freundlich and Langmuir isotherms. The adsorption affinity of clays and Pahokee peat for monotungstates follows the order: Pahokee peat>kaolinite>montmorillonite>illite; for polytungstates, the order is as follows: kaolinite>Pahokee peat>montmorillonite>illite. Results of this study suggest that the charges of the clay mineral surface, tungsten species, and solution pH are the main factors controlling tungsten adsorption. Moreover, polymeric tungsten species (i.e., metatungstate) appear to be more mobile in the environment than monomeric tungstate.

A Markov chain method for simulating bulk density profiles in boreal peatlands

Bulk density is a key determinant of numerous physical characteristics in peat including hydraulic conductivity, smouldering combustion vulnerability, and water retention in the unsaturated zone. A Markov chain model based on peat type (primarily Sphagnum, sedge, and sylvic peats) was applied to the depth-wise structure of boreal peatlands using 143 cores from western Canada as source data. Bulk density and peat type were modelled in 2160 simulated peat profiles by driving Markov chains associated with bulk density distributions by peat type and depth. The model closely reproduced the expected change in bulk density between vertically adjacent peat horizons. Markov-derived peat profiles showed somewhat greater variance in organic matter load in the upper 135cm compared to observed cores due to the lack of whole-profile bias or trends in density. The method and derived Markov chains shown here have utility in hydrological modelling, regional carbon estimates, and in the modelling of disturbances such as wildfire.