Peat Formation Research Articles

Impacts of the Wetland Environment on Demographic Development During the Neolithic in the Lower Yangtze Region—Based on Peat and Archaeological Dates

Wetlands were important resources for the hunting–gathering and early farming communities in coastal areas in the Neolithic. However, the relationship between the development of the wetland environment and the human population remains unclear due to the lack of successive wetland environmental changes throughout the Holocene in coastal areas. Here, the summed probability distributions (SPD) of radiocarbon dates of peat were used as an indicator and combined with archaeological radiocarbon dates to reconstruct the wetland environmental and demographic changes during the Neolithic in the lower Yangtze region. The results showed that the shifts in demographic centers and population development were related to wetland environment with peat formation. The first shift of the demographic center was from the hilly regions to the coastal plain and occurred during ca. 8,300–8,000 cal yr BP, which might be caused by the attractiveness of survival resources offered by the coastal wetland environment and the 8.2 ka event. The second shift occurred from the Ningshao Plain to the Taihu region and might be attributed to the widespread waterlogged environment in the Ningshao Plain. The peak of demographic development coincided with the peak of peat formation during the middle Holocene in the lower Yangtze region, indicating that the wetland environment facilitated changes in human societies. The formation of peat might be related to the sea-level and El Niño-Southern Oscillation events; however, further studies are required for deep comprehension. The present study is an attempt at identifying the past impacts of the wetland environment on demographic development and can form the basis for a more comprehensive understanding of the interactions between the humans and their living environment.

Peat formation and accumulation mechanism in northern marginal basin of South China Sea

In the present study, the coal-rock organic facies of Oligocene Yacheng Formation of the marginal basin in the South China Sea were classified and divided. In addition, through the correlations of the large-scale coal-bearing basins between the epicontinental sea and the South China Sea, it was concluded that the coal forming activities in the South China Sea presented particularity and complexity. Furthermore, the coal forming mechanisms also presented distinctiveness. The marginal basins in the South China Sea consist of several large and complex rift or depression basins, which are distributed at different tectonic positions in the South China Sea. Therefore, the marginal basins in the South China Sea are not simple traditional units with onshore continental slopes extending toward the deep sea. The marginal basins are known to consist of multi-level structures and distinctive types of basins which differ from the continental regions to the sea. During the Oligocene, the existing luxuriant plants and beneficial conditions assisted in the development of peat. Therefore, the Oligocene was the significant period for the formation and aggregation of the peat. However, the peat did not form in unified sedimentary dynamic fields, but instead displayed multi-level geographical units, multiple provenance areas, instability, and nonevent characteristics. As a result, the marginal basins in the South China Sea are characterized by non-uniform peat aggregation stages. In another words, the majority of the peat had entered the marine system in a dispersive manner and acted as part of the marine deposits, rather than during one or several suitable coal-forming stages. These peat deposits then became the main material source for hydrocarbon generation in all of the marginal basins of the South China Sea. The study will be of much significance for the hydrocarbon exploration in the marginal basins of the South China Sea.

ЭКОЛОГИЧЕСКИЙ ФОН ИННОВАЦИЙ РАННЕГО НЕОЛИТА СЕВЕРА ЗАПАДНОЙ СИБИРИ

In the mid-7th — early 6th millennium BC at the Mesolithic–Neolithic transition, a number of innovations appeared in the lifeways of people in the West Siberian taiga, including the first appearance of pottery (the defining criterion for the onset of the Neolithic), the intensification of the subsistence economy with an increasing role of aquatic resources, and the transition to a less mobile lifestyle. These innovations were reflected in the construction of long-term open and few fortified settlements, including circular layouts and the construction of ritual mounds (kholmy). These improvements attest to significant changes in subsistence economy as well as worldviews of the hunter-fisher-gatherers of the taiga zone of West Siberia. The emergence of these innovations chronologically coincides with the most prominent global climatic cooling event of the Holocene, which took place around 6.2 thousand years cal BC (the so-called 8.2 ka BP event) and had a substantial impact on the ancient societies of Europe and Southwest Asia. To reconstruct the paleoclimate of northern West Siberia, the most informative source to date are peatbogs, which contain, as a rule, complete sedimentation sequences of all Holocene periods, allowing a greater degree of reliability in using scientific methods in paleogeographical reconstructions. This article reviews current evidence on features and age of the peat formation process and additional information on the Early Holocene paleoclimatic developments in northern West Siberia. The preliminary data indicate that favourable climatic conditions led to balanced and probably abundant environmental resources in the early Atlantic period. At the same time, the sparsely populated territory might have seen the arrival of new population groups into the region, which might have introduced or triggered a number of socio-economic innovations such as the construction of fortified settlements with complex layouts and the tradition of clay pottery manufacture.

Hydrocarbon Generation Potential and Depositional Setting of Eocene Oil-Prone Coaly Source Rocks in the Xihu Sag, East China Sea Shelf Basin.

The Xihu Sag in the East China Sea Shelf Basin is a focus for hydrocarbon exploration and development. Hydrocarbons in the Xihu Sag are believed to have mainly originated from coals in the Paleogene Pinghu Formation (shortened as Pinghu coal). In this study, the hydrocarbon generation potential, origin of organic matter, and depositional setting of the Pinghu coal were analyzed by means of optical microscopic analysis, bulk organic geochemistry, and molecular geochemistry analysis. The results reveal that the maceral compositions of the Pinghu coal are characterized by a predominance of vitrinite (73.91–96.13%) with relatively high contents of liptinite (1.47–23.02%) and only minor amounts of inertinite (0–5.18%). Type II–III kerogen and high values of TOC (total organic carbon) (8.24–56.77%), EOM (extractable organic matter) (14 601–112 259 ppm), and HI (hydrogen index) (178.76–291.18 mg·HC/g·TOC) indicate that the Pinghu coal is both gas- and oil-prone and could not only generate but also expel hydrocarbons. The results of vitrinite reflectance (0.54–0.90%), Tmax (421–453 °C), and biomarker-related parameters, including CPI (carbon preference index) (1.10–1.61), OEP (odd-to-even predominance) (1.09–1.49), 22S/(22S + 22R) for C31 homohopane (0.59–0.62), and 22S/(22S + 22R) for C32 homohopane (0.57–0.60), suggest that these coaly source rocks have entered the hydrocarbon generation threshold, most of which have entered the expulsion threshold. Biomarker-related parameters of ∑n-C21-/∑n-C22+ (0.38–3.62), Pr/Ph (3.33–9.23), Pr/n-C17 (1.91–14.88), Ph/n-C18 (0.35–1.83), 22S/(22S+22R) of C31 homohopane (0.59–0.62), 22S/(22S + 22R) of C32 homohopane (0.57–0.60), 1,2,7-TMN/1,3,7-TMN (0.74–14.39), and 1,2,5-TMN/1,3,6-TMN (2.22–21.07) suggest that organic matter in the Pinghu coal was deposited under relatively oxic peatland conditions characterized by a predominance of terrestrial higher plant input, especially the resin-rich Pinaceae and Taxodiaceae. The absence of combustion-derived PAHs indicates that neither vegetation fire nor peat fire occurred very frequently during the formation of peat. Areas in the Xihu sag with considerable thicknesses of coal should be paid particular attention for future hydrocarbon exploration. From a global perspective, Cenozoic coaly source rocks, which are characterized by a relatively high content of aliphatic components, should be paid special attention for their oil-prone properties related to the advent of conifer plants.

Evaluation of hydrocarbon potential with insight into climate and environment present during deposition of the Sonari lignite, Barmer Basin Rajasthan

Lignite samples from the Sonari mines of Barmer Basin, Rajasthan, India have been studied for the first time by applying advanced petrochemical techniques. The objective of the study was to reconstruct Paleomire conditions and to examine the source rock potential of the lignite-bearing sequence. Based on the mean huminite/vitrinite reflectance values (0.24–0.31%Ro), all of the samples studied are lignite B in rank. Geochemical analysis results show, the atomic ration H/C and O/C ranges from 0.03–0.15 and 0.27–0.61 respectively, hydrogen index (HI) and oxygen index (OI) ranges from 173 to 256 mg HC/g TOC and 29–55 mg CO2/g TOC respectively, with Tmax value (415–416 °C), entails these lignites are thermally immature and contain type III kerogen. The studied lignites have total organic carbon (TOC), and S2 values vary from 41.24–49.19wt% and 78.53–119.81 mg HC/g rock, respectively, which indicate that these lignites may be served as good hydrocarbon source rock.The lignites are principally composed of huminite (mean 47.5 vol%) and inertinite (mean 31.4 vol%) group of macerals with a low concentration (mean 8.5 vol%) of liptinite macerals. The predominance of attrinite in the Sonari lignite samples suggests that woody vegetation has undergone significant degradation. Petrographic indices such as TPI (Tissue preservation index; 0.92–2.13), GI (Gelification index; 0.97–8.25), GWI (Groundwater influence index; 0.34–1.50), and VI (Vegetation index; 0.16–1.84) indicate deposition in a wet forest paleomire and peat formation under ombrotrophic to mesotrophic hydrogeological conditions. Ternary plots based on maceral and microlithotype entails fluctuating water table condition during peat deposition.The GC-MS (Gas chromatography–mass spectrometry) data shows that the ratios, Pr/Ph pristine/phytane (˂1), Pr/C17 (0.57), Ph/C18 (0.25) and carbon preference index (CPI) value 3.73 along with δ13C (−25.04%) values indicate that the Sonari lignites are composed primarily of gymnosperms taxa which formed under relatively dry and cold paleoclimatic conditions. Besides, FT-IR (Fourier-transform infrared spectroscopy) spectra give the signature of a C–H aliphatic stretching region and predominate methylene group in the aliphatic carbon region, which is also observed in the NMR (Nuclear magnetic resonance).

Seasonal rainfall patterns in stable carbon isotopes in the Mu Us Desert, northern China during the early and middle Holocene

Intense Asian summer monsoon rainfall responds to high boreal summer insolation and environmental feedbacks in the early and middle Holocene. However, it is unclear what role of the Asian summer monsoon strength might have played for the heterogeneous wetness pattern in northern China. Here, we report two wet periods in the early and middle Holocene by paleosol, lacustrine, and peat stratigraphies in the southeast Mu Us Desert, and that early-Holocene wetness records are common and seen in valleys and missing from valley walls while mid-Holocene wetness records are found everywhere in the region. The preliminary analysis of the stable carbon isotopic composition (δ13C) of soil carbonate and organic carbon from a riverine dune–paleosol sequence in a river valley reveals that wet springs/falls with dry summers frequently prevailed in the early Holocene, while wet summers with dry springs/falls became predominant in the middle Holocene. Strong-wind and low-temperature springs and falls on valley walls and uplands cause eolian sedimentation faster than soil formation but weak-wind and warmer-soil temperature in valleys facilitate vegetation metabolism and thus soil formation. Warm summer rainfall with no strong northwesterly wind causes paleosol, lacustrine and peat formation either in valleys or on uplands. The early-Holocene heterogeneous and middle-Holocene uniform wetness records are indeed controlled by seasonal hydroclimate conditions but not a single factor of summer monsoon rainfall strength in the southeast Mu Us Desert.

The oldest extant tropical peatland in the world: a major carbon reservoir for at least 47 000 years

Tropical peatlands in Southeast Asia cover ∼25 million hectares and exert a strong influence on the global carbon cycle. Recent widespread peatland subsidence and carbon dioxide emissions in response to human activity and climate change have been well documented, but peatland genesis remains poorly understood. Unlike coastal peatlands that established following sea-level stabilization during the mid-Holocene, inland peatlands of Borneo are little studied and have no apparent environmental constraint on their formation. Here, we report radiocarbon dates from the Upper Kapuas Basin which show inland peat formation since at least 47.8 thousand calibrated radiocarbon years before present, ka. We provide a synthesis of new and existing peat basal dates across Borneo, which shows a hiatus in peat genesis during a cool and dry period from 30 to 20 ka. Despite likely peat degradation during that period, the Upper Kapuas is still exceptionally deep, reaching a maximum depth (determined from coring) of 18 m. Our best estimate of mean peat depth over 3833 km2 of the Upper Kapuas is 5.16 ± 2.66 m, corresponding to a carbon density of 2790 ± 1440 Mg C ha−1. This is one of the most carbon-dense ecosystems in the world. It withstood the glacial-interglacial climate transition and remains mostly intact, but is increasingly threatened by land-use change.

Source-to-sink system for peat accumulation in marginal basins of the South China Sea with the Qiongdongnan Basin as an example

In the coal-bearing deposits of the Qiongdongnan Basin in the South China Sea, coal seams are for the most part extremely thin, typically less than 0.5 m. Coal streaks are commonly observed but are not concentrated. In addition, the ash content of the coal components is very high, indicating that the geological conditions of peat accumulation and coal formation were very unstable. For these reasons, it can be speculated that at the time of development, peat mires were relatively poor, in terms of inheritance and continuity, and were commonly not preserved. Coal measures, coal seams (in situ peat accumulation over long distances) and dispersed terrigenous sedimentary organic matter, which together constitute a type of complex coal source-to-sink system found in basin-marginal basins, include three aspects. (1) The material is homologous: whether autochthonous accumulation, allochthonous accumulation or dispersed organic matter is present, the total organic matter source is homologous, i.e. suitable for development and plant growth. (2) The process of organic matter transport (channel) is divided into three forms: vertical accumulation in situ, transport to relatively fixed areas by flowing water, and transport by other mechanisms with long-distance dispersion and drift. (3) There are three types of aggregation forms: vertical accumulation in situ, transport from flowing water to relatively fixed areas away from where plants grow and aggregate, and deposition in deep-water basins fixed with other substances; the latter type requires a period of time for long-distance dispersion and drift, including channel flow and surface flow. KEY POINTS From plant growth to peat formation, the ‘source–channel–sink system’ of coal formation is ‘sensitivity to sedimentary environments and complexity of distribution’. Convergence of coal-series, coal seam (in situ peat aggregation and allochthonous aggregation), and terrestrial dispersed organic matter deposition, constitute a complex coal-measure source–sink system. Source includes substance homology, channels include in situ vertical accumulation and dispersion drift in short and long distances, with convergence forms including in situ vertical accretion, remote sink and dispersion in deep-water basin.

Stable isotopes of organic carbon, palynology, and petrography of a thick low-rank Miocene coal within the Mile Basin, Yunnan Province, China: implications for palaeoclimate and sedimentary conditions

Coal contains detailed long-term records of contemporaneous environment, climate, and subsequent diagenetic processes. Stable isotopes of carbon, petrological, palynological, and mineralogical analyses were carried out on a 28 m thick low-rank Miocene coal seam from the Mile Basin, Yunnan Province, China for the purpose of deciphering the palaeoclimate and sedimentary conditions during peat deposition. The coal is characterized by both pale and dark lithotypes. Palynological analyses show that both lithotypes are dominated by angiosperms, which is interpreted to indicate a moderately warm climate. The absence of Fagus and Taxodiaceae pollen suggests that there may have been dry periods during peat accumulation; in general, both Fagus and Taxodiaceae require a constant wet environment in order to proliferate. Organic petrography, δ13C, and gypsum concentrations corroborate that there were alternating drier and wetter periods within the palaeomire during peat accumulation. The fine-scale variability in the δ13C signature appears to be controlled by plant type. Angiosperm/gymnosperm ratios and Vegetation Index are directly correlated with δ13C isotopic values. Plant type, however, seems to be proximally controlled by water level. Angiosperms were more dominant during times of lower water table or less moist conditions, interpreted to correspond to less negative values of δ13C. The correlation of greater concentrations of gypsum with less negative δ13C values also supports drier conditions. However, in addition to the fine-scale variability, four larger scale cycles are defined based on less negative δ13C values. A less negative δ13C isotopic signature demarcates the top of each of these cycles, which represent spikes of lower water table and/or drier conditions. In addition, a general correlation of the δ13C variations in the studied coal seam with atmospheric CO2 suggests that the atmosphere also had a significant influence on peat formation in the Mile Basin. Although the Mile Basin palaeomire accumulated over a long time, an integrated approach to its analysis has demonstrated considerable variation in palaeoclimate. Changes in wetness/dryness had a direct effect on the ecological composition of the palaeomire. These floral changes would not have only been restricted to the palaeomire but most likely had a regional influence. Thus, detailed analysis of coals can yield useful, insightful and practical knowledge on past regional palaeoenvironmental conditions, which can then be placed within a global context.

Soils and Sediments of the Lacustrine-Alas Depressions in Tundra Zone of the Kolyma Lowland

Pedogenesis on the terraces of lacustrine–alas depressions in the tundra zone of the Kolyma Lowland takes place on sediments that are different in genesis but have significantly similar composition and properties. Soil morphology and soil cover patterns on terraces and slopes of depressions reflect the main trends of the Holocene pedogenesis and the rearrangement of the environment. On the terraces of the upper and middle levels, as well as on the interfluves, the major pedogenic trend is cryozem formation. On the lower terraces and in the bottoms of lacustrine–alas depressions, gleyzation and peat formation are considered to be stable and progressing processes. Soil formation is affected by close permafrost table (<1 m); therefore, all soils are qualified for Cryosols.

Environmental evolution of peat in the Sacramento – San Joaquin Delta (California) during the Middle and Late Holocene as deduced from pollen, diatoms and magnetism

We studied the sequence of climatic and hydrological events associated with the formation of peat during the Holocene, using pollen, diatoms and environmental magnetism from peat cores at three locations in the Sacramento-San Joaquin Delta of California: Browns Island, Franks Wetland and Webb Track Levee. Our data show that peat first formed under relatively dry conditions in a freshwater environment before 6.5 ka BP. Subsequently, pollen accumulation rates were highest prior to intervals with high peat accretion rates but are inversely correlated with organic accumulation rate. Intervals of high peat accretion were preceded by pulses of terrigenous material. During intensive drainage episodes, high flows delivered abundant, coarser-grained sediment to the marshes, which inundated the existing vegetation and decreased the rate of biochemical decay. The build-up of undecomposed organic material led to the acceleration of peat accretion. Our data support the rarely discussed hypothesis that most of the peat in the Sacramento-San Joaquin Delta formed in freshwater marshes that were fed by rivers draining from the Sierra Nevada, rather than in saltwater wetlands resulting from sea level rise and estuarine submergence. This result has important implications for current attempts to remediate and restore the Delta ecosystem.

Nature conservation and resource characteristic of peat reserves in Ukraine

Peat reserves in the world are estimated. The results of the peat resource base estimation are given; the uneven distribution of peat resources in the regions of Ukraine is justified. Classification of peat deposits is carried out. Peat resources are calculated by industrial significance, the degree of exploration, development groups. All categories of peat reserves are classified as balance sheet, approved in accordance with the established procedure as off-balance sheet, but at present the use of which is not economically feasible due to small quantity, low power, poor quality, special complexity of operating conditions, or within the limits of polder systems or plots drained from application of drainage, located on the territory of nature reserves or sanctuaries. Today the total area of drained deposits and plots in Ukraine is within the zero depth of 162.0 thousand hectares, within the industrial depth — 1058 Mm2 , geological reserves — 419.6 Mt, the amount of deposits is 395. The degree of land peat formation. The areas of drained peatlands in oblasts are surveyed and analyzed. The country’s peat resources are used very intensively and in connection with the privatization of land, it is necessary to predict the further intensification of the usage of peat deposits for the development of collective farming, the priority ransom for individuals and farms, the peat production increase for fertilizers, for the production of insulating plates, litters, etc.

Analysis of prehistoric brown earth paleosols under the podzol soils of Exmoor, UK

AbstractThe deforestation of the upland landscapes in southwest Britain during prehistory is an established archaeological narrative, documenting human impacts on the environment and questioning the relationship of prehistoric societies to the upland landscapes they inhabited. Allied to the paleoenvironmental analyses of pollen sequences, which have provided the evidence of this change, there has been some investigation of prehistoric paleosols fossilized under principally Bronze Age archaeological monuments. These analyses identified brown earth soils that were originally associated with temperate deciduous woodland, on occasion showing evidence of human impacts such as tilling. However, the number of analyses of these paleosols has been limited. This study presents the first analysis of a series of pre‐podzol brown earth paleosols on Exmoor, UK, two of which are associated with colluvial soil erosion sediments before the formation of peat. This study indicates these paleosols are spatially extensive and have considerable potential to inform a more nuanced understanding of prehistoric human impacts on the upland environments of the early‐mid Holocene and assess human agency in driving ecosystem change.

Implications for peat formation in Maritsa-West Basin, SE Bulgaria: Insights from organic petrology, palynology and biomarker assemblage

The paper reports the results of the organic petrological, palynological and geochemical characterization of lignite samples from the Kipra lignite seam (Late Miocene, Maritsa-West Basin, Bulgaria). The bulk of the organic matter (OM) is represented by highly gelified detrohuminite with locally abundant leaf-derived ulminite. Liptinite group is characterized by predominance of microsporinite and liptodetrinite, locally with cutinite and fluorinite. Terpene resinite and suberinite are rare. Low TPI and high GI indices indicate peat formation from vegetation with low preservation potential, deposited under water-logged environment of marsh- or fen-type. The palynological results reveal a vegetational community representing different habitats (i.e. mesophytic, marginal and aquatic). The relatively poor preservation of the palynomorphs, however, suggests vegetation that was more diverse during peat formation. Although gymnosperm palynomorphs predominate, the gymnosperm organic matter contribution was probably minor as indicated by the low contents of sesqui- and diterpenoid biomarkers. Because of the absence of triterpenoid biomarkers of neither oleanane, nor lupane or ursane-type, it is considered that angiosperms that do not synthesize their precursors predominated, or the depositional environment had unfavorable characteristics, which prevented the transformation of the triterpenoid precursors.The extractable organic matter yield from the Kipra lignite is low, and dominated by saturated compounds, while polar compounds and asphaltenes occur in low amounts. Aromatic compounds are completely absent. The saturated hydrocarbons are mainly composed of n-alkanes, accompanied by minor amounts of branched- (including isoprenoids) and cycloalkanes, sesqui- and diterpenoids, steroids and hopanoids. Straight chain alkanes are prevailed by long-chain homologues, but show rather mature distribution with CPI ~ 1. Biological (e.g. bacterial) activities and/or environmental control are considered as the main factor/s controlling the observed uncommon n-alkane distributions. A rather uncommon pentacyclic terpenoid, i.e. onocerane I, was tentatively identified in one sample, based on its characteristic fragmentation pattern. Based on its presence, a very specific plant community is considered, and/or specific palaeoenvironmental conditions occurred at least temporarily during the peat formation. However, the responsible plants could not be identified. The low amounts of hopanoid biomarkers, together with the low amounts of n-alkanones, are consistent with limited aerobic biodegradation of the plant remains. The mature 22S/(22S + 22R) C30 hopane ratio (~ 0.55), as well as the random huminite reflectance values (~0.3–0.4%), which are more than twice higher than previously reported, argue for a local increase of coalification degree, presumably due to increased thermal influx around major faults.

From Understanding to Sustainable Use of Peatlands: The WETSCAPES Approach

Of all terrestrial ecosystems, peatlands store carbon most effectively in long-term scales of millennia. However, many peatlands have been drained for peat extraction or agricultural use. This converts peatlands from sinks to sources of carbon, causing approx. 5% of the anthropogenic greenhouse effect and additional negative effects on other ecosystem services. Rewetting peatlands can mitigate climate change and may be combined with management in the form of paludiculture. Rewetted peatlands, however, do not equal their pristine ancestors and their ecological functioning is not understood. This holds true especially for groundwater-fed fens. Their functioning results from manifold interactions and can only be understood following an integrative approach of many relevant fields of science, which we merge in the interdisciplinary project WETSCAPES. Here, we address interactions among water transport and chemistry, primary production, peat formation, matter transformation and transport, microbial community, and greenhouse gas exchange using state of the art methods. We record data on six study sites spread across three common fen types (Alder forest, percolation fen, and coastal fen), each in drained and rewetted states. First results revealed that indicators reflecting more long-term effects like vegetation and soil chemistry showed a stronger differentiation between drained and rewetted states than variables with a more immediate reaction to environmental change, like greenhouse gas (GHG) emissions. Variations in microbial community composition explained differences in soil chemical data as well as vegetation composition and GHG exchange. We show the importance of developing an integrative understanding of managed fen peatlands and their ecosystem functioning.

Rapid peat development beneath created, maturing mangrove forests: ecosystem changes across a 25-yr chronosequence.

Mangrove forests are among the world's most productive and carbon-rich ecosystems. Despite growing understanding of factors controlling mangrove forest soil carbon stocks, there is a need to advance understanding of the speed of peat development beneath maturing mangrove forests, especially in created and restored mangrove forests that are intended to compensate for ecosystem functions lost during mangrove forest conversion to other land uses. To better quantify the rate of soil organic matter development beneath created, maturing mangrove forests, we measured ecosystem changes across a 25-yr chronosequence. We compared ecosystem properties in created, maturing mangrove forests to adjacent natural mangrove forests. We also quantified site-specific changes that occurred between 2010 and 2016. Soil organic matter accumulated rapidly beneath maturing mangrove forests as sandy soils transitioned to organic-rich soils (peat). Within 25yr, a 20-cm deep peat layer developed. The time required for created mangrove forests to reach equivalency with natural mangrove forests was estimated as (1) <15yr for herbaceous and juvenile vegetation, (2) ~55yr for adult trees, (3) ~25yr for the upper soil layer (0-10cm), and (4) ~45-80yr for the lower soil layer (10-30cm). For soil elevation change, the created mangrove forests were equivalent to or surpassed natural mangrove forests within the first 5 yr. A comparison to chronosequence studies from other ecosystems indicates that the rate of soil organic matter accumulation beneath maturing mangrove forests may be among the fastest globally. In most peatland ecosystems, soil organic matter formation occurs slowly (over centuries, millennia); however, these results show that mangrove peat formation can occur within decades. Peat development, primarily due to subsurface root accumulation, enables mangrove forests to sequester carbon, adjust their elevation relative to sea level, and adapt to changing conditions at the dynamic land-ocean interface. In the face of climate change and rising sea levels, coastal managers are increasingly concerned with the longevity and functionality of coastal restoration efforts. Our results advance understanding of the pace of ecosystem development in created, maturing mangrove forests, which can improve predictions of mangrove forest responses to global change and ecosystem restoration.

Participation of Plants in the Formation of Polycyclic Aromatic Hydrocarbons in Peatlands

The composition of polycyclic aromatic hydrocarbons (PAHs) in vegetation of natural hummocky peatlands in the forest-tundra subzone of the Komi Republic and its possible impact on the composition of polyarenes in peat were assessed. The content of polyarenes was estimated by the method of highly efficient liquid chromatography. The accumulation of polycyclic aromatic hydrocarbons was the highest in Polytrichum strictum, Betula pubescens, and shoots of Picea abies and smaller in Betula nana L., Salix lapponum L., and Carex limosa L. with the domination of low-molecular-weight PAHs. We did not reveal dibenz[a,h]anthracene and benzo[ghi]perylene in plants: they could be the products of soil-forming processes. It is shown that distribution patterns of PAHs in the permafrost-affected soils of peat mounds (Hemic Folic Cryic Histosols) and in the soils of open-water mire pools (Fibric Floatic Histosols) are similar. Small quantities of low-molecular-weight polyarenes were normally accumulated in the seasonally thawed layer. The content of heavy structures (mainly, benzo[ghi]perylene) strongly increased at the contact with permafrost and then slightly decreased in the underlying permafrost. The composition of PAHs in the active layer mainly depended on composition of polyarenes in plants. At the contact with permafrost, the active synthesis or release of high-molecular-weight compounds took place. The influence of the composition of PAHs in plants on their composition in peat greatly depended on the degree of peat decomposition. Reasoning from the natural model of peat formation in open-water mire pools, the composition of polyarenes in the upper peat horizons of such sites was affected by recombination of low-molecular-weight hydrocarbons in Sphagnum riparium and Eriophorum sp. In the course of long-term soil development, the decomposition of complex organic compounds in plant tissues (particularly, in Eriophorum sp.) results in the formation of heavy PAHs with a simultaneous increase in the content of low-molecular-weight polyarenes.

Roots, Tissues, Cells and Fragments—How to Characterize Peat from Drained and Rewetted Fens

We present analyses of macroscopic and microscopic remains as a tool to characterise sedge fen peats. We use it to describe peat composition and stages of peat decomposition, to assess the success of rewetting of a formerly drained fen, and to understand the workings of these novel ecosystems. We studied two percolation fen sites, one drained and one drained and rewetted 20 years ago. Years of deep drainage have resulted in a layer of strongly decomposed peat which lacks recognizable macro-remains. We could associate micro-remains with macro-remains, and thus still characterise the peat and the plants that once formed it. We show that the strongly decomposed peat is of the same origin as the slightly decomposed peat below, and that is was ploughed. We present descriptions of eight types of the main constituent of sedge peat: plant roots, including Carex rostrata type, C. lasiocarpa/rostrata type, C. limosa type, C. acutiformis type, C. echinata type, Phragmites australis type, Cladium type, Equisetum type. We describe three new non-pollen palynomorph types (microscopic remains) and five new subtypes. The rewetted fen provides insights into plant succession after rewetting and the formation of peat that predominantly consists of roots. Results indicate that leaf sheaths may be a consistent component of the peat.

Landsat based distribution mapping of high-altitude peatlands in Hindu Kush Himalayas — a case study of Broghil Valley, Pakistan

In the alpine regions of Hindu Kush, Himalayas and Karakorum, climatic and topographic conditions can support the formation of peat, important for the livelihood of the local communities, and ecological services alike. These peatlands are a source of fuel for the local community, habitat for nesting birds, and water regulation at source for rivers. Ground-based surveys of high-altitude peatlands are not only difficult, but also expensive and time consuming. Therefore, a method using cost-effective remote sensing technology is required. In this article we assessed the distribution and extent of high-altitude peatlands in a 2000 ha area of Broghil Valley using Landsat 8 data. The composite image was trained using a priori knowledge of the area, and classified into peatland and non-peatland land covers using a supervised decision tree algorithm. The Landsat-based classification map was compared with field data collected with a differential GPS. This comparison suggests 82% overall accuracy, which is fairly high for high altitude areas. The method was successfully applied and has the potential to be replicated for other areas in Pakistan and the high-altitude regions of the neighbouring Asian countries.

THE GROSS CHEMICAL COMPOSITION OF INITIAL SOILS OF VERKHOVYNA’S WATERSHED RIDGE OF THE UKRAINIAN CARPATHIANS

Problem Statement and Purpose. The intrasonal initial organogenic soils are formed with in the Verkhovyna’s watershed ridge of the Ukrainian Carpathians. They are dated to the access to the daily surface of dense sandstones of the Krosno zone. The aim of research is to establish the features of the gross chemical composition of the initial soils of the Verkhovyna’s watershed ridge of the Ukrainian Carpathians at differents tages of evolutionary development have been defined in this work. The investigate the impact of the major cenosis-forming species on the change of their gross chemical composition and morphological features has been investigated. Data & Methods. The analysis of references, source materials, the results of personal field studies based on morphological characteristics and consideration of succession of vegetation changes allowed to form an evolutionary series of initial soils within the area of research:embryonic soils-soil-like bodies-initial (primary) soils - primitive (young) soils. Within the study area, The morphological features of the initial soils were studied and samples were taken for laboratory-analytical studies. Results. The characteristic feature of gross chemical composition of initial soils at different stages of development is the accumulation of one and a half oxids of silica, Aluminum and Iron compounds, which is caused by the introduction of these elements from plant precipitation and atmospheric sediments. This is confirmed by them formation of the elemental composition of leaf lichens and mosses, where tlie accumulation of compounds of Aluminum and Fenun, as well as Calcium and Magnesium due to biological cycling is noted .The calculated eluvial-accumulative coefficients attested the total removal of oxides at all stages of evolution of the initial soils. Them formation of the gross chemical composition of the initial soils made it possible to diagnose file main EGP, which form the morphological features of the initial soils at different stages of development. Decarbonisation of soil-forming rocks is a prerequisite for the beginning of embryonic soil formation and formation of embryonic soil; fersialization - the process of accumulation of movable forms of iron is based on decarbonisation, which is inherent in the soil-like body; humus - socialization - transformation of mineral mass under the action of neutral and slightly acidic humus substances, which contributes to the partial removal of bases and the formation of sod-humus ( peaty ) horizon; peat formation, which is characteristic of all stages (except the embryonic one) and is determined mainly by the climatic conditions of thestudying area.