Bog Sediments Research Articles

The Differences in the Li Enrichment Mechanism between the No. 6 Li-Rich Coals and Parting in Haerwusu Mine, Ordos Basin: Evidenced Using In Situ Li Microscale Characteristics and Li Isotopes

As a potential strategic mineral resource, lithium (Li) in coal measures (including coal and parting) has attracted increasing attention from scholars globally. For a long time, Li in coal measures has been studied mainly on the macro-scale (whole rock); however, the microscopic characteristics of Li and Li isotope variations in coal measures are less well known. In this study, the No. 6 coal measures in the Haerwusu Mine were studied using ICP-MS, XRD, SEM-EDS, MC-ICP-MS, and LA-ICP-MS. The geochemical and mineralogical characteristics, the microscale distribution of Li in minerals, and the Li isotopes of Li-rich coal and parting in the No. 6 coal measure were investigated. The results show that the Li content in the No. 6 coal seam ranges from 3.8 to 190 μg/g (average 83 μg/g), which is lower than the parting (290 μg/g) and higher than the comprehensive evaluation index of Li in Chinese coal (80 μg/g). LA-ICP-MS imaging showed that Li in the coal is mainly contained within cryptocrystalline or amorphous lamellae aluminosilicate materials, and the Li content in lenticular aggregate kaolinite is low. The Li in parting is mainly found in illite/chlorite. The δ7Li of the coals was 3.86‰, which may be influenced by the input of the source rock. The δ7Li of the parting (7.86‰), which was higher than that of the coal, in addition to being inherited from the source rock, was also attributed to the preferential adsorption of 7Li by the secondary clay minerals entrapped in the parting from water during diagenetic compaction. Finally, by integrating the peat bog sediment source composition, sedimentary environment evolution, and Li isotope fractionation mechanism of No. 6 coal, a Li metallogenic model in the Li-rich coal measure was initially established. In theory, the research results should enrich the overall understanding of the Li mineralization mechanism in coal measures from the micro-scale in situ and provide a scientific basis for the comprehensive utilization of coal measure resources.

The maximum extent of the Odranian Glaciation (Saalian, MIS 6) in the South Podlasie Lowland (SE Poland) in the light of sites with lacustrine deposits of the Mazovian Interglacial

Based on the analysis of the geological context and palynological studies performed on lake and bog sediments in the Southern Podlasie Lowland, a new concept of the maximum extent of the Odranian Glaciation (Saalian, MIS 6) is presented for the study area. It is depicted by the Siedlce−Łosice−Kornica zone of end moraines, which so far was considered as stadial-rank or as the Wartanian ice sheet limit. To the south of this zone, near Biała Podlaska and in the Łuków Plain, there occur numerous sites with fossil deposits of the Mazovian Interglacial (MIS 11c). Sites with new documentation, i.e., Wólka Domaszewska, Kolonia Bystrzycka, Przytulin, Hermanów, and Skrzynka are located about 30 km to the south and 60 km to the west of the Biała Podlaska area. Palynological analysis unequivocally indicates the presence of a vegetation succession characteristic of the Mazovian Interglacial. In all sites, deposits of the Mazovian Interglacial are covered by lacustrine sediments of the Liviecian Glaciation (Fuhne, MIS 11b-MIS 10) or mineral sediments of the Vistulian Glaciation (Weichselian, MIS 2) and the Holocene. The sediments infill paleolakes carved in glacial tills of the Sanian 2 Glaciation (MIS 12). The lake sediments of the Mazovian Interglacial and the overlying biogenic and mineral deposits occur in the analysed sites directly below the surface. They are never covered by glacial deposits, which suggests that the Odranian ice sheet did not cover the study area. The location of the lake and bog sites with their geological analysis allow for the precise depiction of the eastern limit of the Odranian ice sheet lobe, which in the study area correlates with the limit suggested in the late 19th century. The Odranian ice sheet did not cover Southern Podlasie.

Hillslope and vegetation response to postglacial warming at Bear Meadows Bog, Pennsylvania, USA

AbstractConnecting changes in erosion and vegetation is necessary for predicting topographic and ecologic change in thawing permafrost landscapes. Formerly periglacial landscapes serve as potential analogs for understanding modern permafrost landscape change, yet compared to paleoenvironmental records at these sites, less is known about concurrent geomorphic processes, particularly their rates and relationships to climate change. Here, we target sediments preserved in a central Appalachian peat bog to reconstruct sedimentation across the last deglacial warming. We use ground-penetrating radar and geochemistry of cored bog sediments to quantify sedimentation timing, style, and provenance. Using 14C dating of sedimentary and geochemical shifts, we connect depositional changes to global climate and local vegetation change. We show that deglacial warming promoted deep soil disturbances via solifluction at ca. 14 ka. In contrast, relatively wetter conditions from ca. 10–9 ka promoted shallow disturbance of hillslopes via slopewash, which corresponds to a time of vegetation change. Our results highlight climate-modulated erosion depth and processes in periglacial and post-periglacial landscapes. The existence of similar erosion and vegetation records preserved regionally implies these dynamics were pervasive across unglaciated Appalachian highlands, aiding in reconstructing erosion responses to warming at a resolution with implications for predicting high-latitude landscape responses to disturbance.

Prehistoric farming in the south-eastern Baltic (Kaliningrad Region, Russia)

The article presents an overview of the currently available palaeoecological data on the prehistoric anthropogenic impact on the environment and emergence of farming in the south-eastern Baltic, an area poorly studied in palaeoenvironmental and archaeological terms. The recently obtained palynological data from the lake and bog sediments along with the existing archaeological finds allow us to consider several stages of prehistoric farming in the south-eastern Baltic. The first indications of forest management – the creation of open deforested areas, wood burning and probably cultivation (propagation) of hazel appear during the Mesolithic, 10 300–6500 cal BP. At about 6500–5200 cal BP, evidence of the first agricultural activity and local animal husbandry emerges. From 5200 cal BP onwards, farming probably occupies a permanent place in the subsistence strategy of the ancient population of the south-eastern Baltic.

Ecological and Wildfire Responses to Rapid Landscape Changes within the Last ~900 Years on the South Haven Peninsula, Dorset (Southern England)

A multi-proxy palaeoenvironmental dataset (LOI, pollen, charcoal, grain sizes and the humification index) was extracted and radiocarbon dated from a sedimentary sequence from Spur Bog, central South Haven Peninsula (Dorset, southern England) to reconstruct ecological and environmental changes within the last ~900 years. These analyses reveal highly unstable environmental conditions at the site, evidencing the occurrence of multiple, often rapid changes during this period. The results significantly expand upon the existing palaeoenvironmental and geomorphological frameworks of the South Haven Peninsula which previously relied upon sparse, vague historical records prior to ~1750 AD. The multi-proxy dataset of Spur Bog sediments recorded a primary “development” phase (~1150–1470 AD) during which marine processes were the dominant control upon environmental conditions at the site, resulting in marked geomorphological changes that lead to the progressive eastward expansion of the South Haven Peninsula. This is followed by a secondary “maturation” phase (~1470–1880 AD) during which the Spur Bog sequence exhibits significant ecological changes in response to fluctuations in sea level, coastal erosion and human activity, demonstrating the vulnerability of the site to future climatic and anthropogenic pressures.

Analysis of surface wetness changes in the Maly Labysh mire in south of Western Siberia during the last two millennia

In this study we investigate peat deposits of a transitional sedge-Sphagnum mire by using a testate amoeba analysis to reconstruct the paleohydrology of the mire for the last two millennia. The Maly Labysh mire is located in a river floodplain in low mountains in the south of Western Siberia. The goal of our research is to evaluate the water table depth changes in the mire due to regional and continental climate changes in the late Holocene. Two short-term dryings of the mire surface in 2100-1900 and 1600-1400 yr BP have been revealed. Afterwards, an unusual shift in the oligotrophic conditions on the mire surface is documented between 1400-1100 yr BP. This indicates some weakening of the influence of the nearby river likely due to a decrease in the precipitation. Then, starting at ca. 900 yr BP the mire gradually came back to transitional conditions again, and its surface moisture remained moderately high without notable fluctuations. The close consistency of the thus revealed periods of short drying with similar events in the development of other lake and bog sediments in the south of Western Siberia indicates the fact of predominant influence of westerlies on the formation of the regional climate.

A 7-ka climatic variability record inferred from peat bog sediments in the north of Bayan Har Mountains, northeastern Tibetan Plateau

Reconstructions of the Holocene (especially the mid-Holocene) climatic and environmental changes may serve as an analogue for future scenarios. About 7 ka of Holocene climatic variability in the north of Bayan Har Mountains on the northeastern Tibetan Plateau is reconstructed, using grain size, magnetic susceptibility, geochemical parameters, and accelerator mass spectrometry 14C chronology from peat bog sediments. The peat’s source is found to be aeolian sediments. Climatic variability from the peat bog sediments during the last 7.3 ka can be divided into four stages: warm and wet from 7.3 to 5.7 cal ka BP; cool and dry (semi-wet) from 5.7 to 2.5 cal ka BP; relatively cool and wet from 2.5 to 1.1 cal ka BP; and cold and dry from 1.1 cal ka BP to present. Mid-late Holocene climate in the north of Bayan Har Mountains was significantly unstable during the last 7.3 ka and characterized by five centennial-scale oscillations: 6.2‒6.0, 4.3‒3.9, 2.5‒2.1, 1.7‒1.4, and 0.7‒0.2 cal ka BP. This mid-late Holocene climate recorded by peat bog deposits is consistent with most lacustrine sediment records in the north of Bayan Har Mountains and its adjacent areas. These lacustrine sediments indicated that the climate on the northeastern Tibetan Plateau was warm and humid in the early Holocene, cold and dry after the mid-Holocene (ca. 7.5‒6.0 cal ka BP), and relatively cool and wet in the late Holocene.

Tracing ancient animal husbandry in tropical Africa using the fossil spore assemblages of coprophilous fungi: a validation study in western Uganda

Fossil spores of coprophilous fungi preserved in lake and bog sediments are well-established palaeoecological tracers for the local history of pastoralism and other animal husbandry. However, applications in Africa are limited by the lack of information on the exact relationship between human activity and fungi growing on large-herbivore dung. Here we use 25 small crater-lake basins in western Uganda, which cover the complete regional gradient of natural vegetation and human impact intensity, as a natural laboratory to assess the relationship between coprophilous fungal spores recovered from recently deposited bottom sediments and the presence and abundance of large domestic herbivores in the surrounding crater basins. We find that the summed abundances of Sporormiella, Sordaria, Podospora and Delitschia, or of these four types plus Cercophora, are the most useful and robust fungal-spore indicators for the presence of domestic large herbivores in an East African context. Chaetomium could also be added to this list, particularly as it may help reduce stochasticity in the often low fossil counts of obligate coprophilous types. Our results suggest that domestic large herbivores, at least when associated with some degree of crop agriculture, leave a clearer signature on fungal-spore assemblages in the lakes’ sediments than large wildlife. Furthermore, they indicate that the typically small number of livestock kept by mixed-subsistence farmers leave a stronger imprint on fungal-spore assemblages than the much larger herds of specialist pastoralists occasionally visiting the lake to drink or bathe.

Ecology, Ecosystem & Conservation Biology

Ecology is the study of the interaction between organisms and their environment. To fulfill the food requirements of increasing population, human activities are affecting the ecosystem. It has never been extra important to comprehend what regulates the dispersal and richness of species, how they intract with each other and their environment, and how biodiversity rejoins to threats by change in climate, invasive species, over-exploitation and destruction of habitat. Issues arising due to climate change, understanding the ecosystem, and the measures required to sustain Earth's life-support systems has become progressively important. In this evolutionary process, human activities have played a prominent role, and those who study vegetation cannot afford to neglect this aspect. Conversion of natural habitats into industrial and agricultural landscapes, and finally into tainted land, is the major influence of humans on the natural environment, posing a great threat to biodiversity. Restoration of ecosystem is an emerging discipline which provides a more suite of tools for the recovery of degraded lands. Restoration of ecology offers a crucial accompaniment to nature reserves as a way for the preservation of biodiversity. An unified understanding of human population growth and changes in agricultural practices with natural recovery processes and restoration ecology offers hope for the future of the environment. Even though ecologists have documented the role of history and historical legacy concept in determining present-day ecological systems, few international conservation assessments consider time scales more than 50 years. Conservation biology is prearranged management of natural resources and natural balance retention, diversity and evolutionary processes in the environment. Conservation strategies in a rapidly changing world need to consider the dynamic biological processes of species and their interactions with their environment: it is here that insights from long-term ecology can guide conservation. Palaeoecological techniques like macrofossils, pollen analysis and sediment chemistry in long-term ecology uses to resolve critical questions to resolve long-term ecological changes and the processes behind such changes. Palaeoecological record uses that preserved in lake and bog sediments as a long-term ecological laboratory. The record delivers exclusive information about ecological impact of environmental change on population, organisms, communities, landscapes and ecosystems over time scales from 50 to 12000 years. New developments mean that palaeoecological studies have high taxonomic precision, fine temporal resolution (typically of ~5 years, and sometimes 1 or 2 years), appropriate numerical methods of analysis, and can benefit from synergies of multi-proxy studies. Palaeoecological studies can help to answer questions such as ¬ In the change of ecosystem what are the major drivers at different time scales? ¬ In a specific ecosystem how much natural variability is there? ¬ How have landscapes changed over time? ¬ What is the native status of particular species? ¬ Which ecological processes are important for maintaining target ecosystems? ¬ How do human activities affect the resilience of ecosystems to climate change? ¬ What time-lags can be expected between climate change and ecosystem response? ¬ How will climate change affect the distribution and impacts of climate-dependent disturbance regimes such as fire? Within the application of long-term ecological data to conservation and management there are many controversies, challenges, and compromises. Recently, a study has emphasized a serious question in practical conservation: Do we know what we want to conserve and how to conserve it? Two opposite ideas are preservation of cultural landscapes and creation of partially 'wild' areas with re-wilding. Long-term ecology has much to pay to conservation as the complexity of processes and patterns in the past, when prudently decrypted, can help to make new ideas about management in the future. Biodiversity loss is a local phenomenon and an in-depth understanding of individual locations is needed to devise solutions. This special issue provides focused study on ecological forecasting and customized decision support tools for a variety of topics. In this Special issue, researchers spatially explicit modeling approaches to address complex interactions, and relationships to solve the following issues: Wildfire, Climate Change Impacts, Species Population Modeling, Wildlife Connectivity, Green Energy Development and Environmental Risk Avoidance conservation problems.

Sedimentary n-alkanes and n-alkanoic acids in a temperate bog are biased toward woody plants

Sedimentary plant waxes and their hydrogen and carbon (δ2H and δ13C) isotopes are important proxies for past hydrologic and vegetation change. However sedimentary waxes accumulate from diverse sources, integrating uncertainties from: (i) variable isotope fractionation among plant species, and (ii) unresolved processes controlling the transport of waxes from plants to sediments. We address these uncertainties by comparing the molecular and isotopic composition of n-alkanes and n-alkanoic acids in recent bog sediments with all major plant species growing in the catchment of Browns Lake Bog (BLB) in Ohio, USA. There are two distinct plant assemblages at BLB, including a forest dominated by trees and a bog shoreline composed of shrubs, woody groundcover, herbs and graminoids. n-Alkane concentrations in trees were 10–300 times higher than in shoreline plants, while n-alkanoic acid concentrations were generally lower and comparable across all species. The overall range of wax δ2H values among individual plants (77‰ for n-C29 alkane and 84‰ for n-C28 alkanoic acid) was likely driven by interspecies differences in biosynthetic δ2H fractionation as well as source water differences between forest and shoreline plants. A considerably smaller range of δ2Hwax values in the bog sediments (9‰ for n-C29 alkane and 11‰ for n-C28 alkanoic acid) suggests that sediments are either biased toward specific plants, or that signal averaging processes during or after deposition are constant. The combined δ2H and δ13C signatures of plant sources and sediments indicate a sediment bias mainly toward trees, with contributions from woody shrubs and groundcover growing in the bog shoreline. Within trees and woody shrubs, we observed δ2Hwax–δ13Cwax relationships of opposite sign for n-C29 alkane and n-C28 alkanoic acid, which we speculate may reflect contrasting seasonal timing of synthesis and plant metabolic status between compound classes. The net apparent δ2H fractionation between precipitation and wax (εapp) was approximately 30‰ larger for n-alkanes (−133‰) than for n-alkanoic acids (−103‰), both at the plant level and in sediments. These results demonstrate the sensitivity of sediments in a hydrologically closed basin to woody plants growing in the associated catchment and can guide εapp estimates for sedimentary records from similar depositional settings.

Authigenic and Detrital Minerals in Peat Environment of Vasyugan Swamp, Western Siberia

Studies of mineral-forming processes in modern peat bogs can shed light on metal concentrations and their cycling in similar environments, especially in geological paleoanalogs. In terms of the mineralogical and geochemical evolution of peat bog environments, the Vasyugan Swamp in Western Siberia is a unique scientific object. Twelve peat samples were collected from the Vasyugan Swamp up to the depth of 275 cm at 25 cm intervals. The studied peat deposit section is represented by oligotrophic (0–100 cm), mesotrophic (100–175 cm), and eutrophic (175–275 cm) peat, and this is underlain by basal sediments (from 275 cm). About 30 minerals were detected using scanning electron microscopy (SEM), X-ray diffraction (XRD), and Raman spectroscopy. The observed minerals are divided into detrital, clay, and authigenic phases. The detrital minerals found included quartz, feldspar, ilmenite, rutile, magnetite, zircon, and monazite. When passing from basal to oligotrophic bog sediments, the clay minerals changed from illite-smectite to kaolinite. Authigenic minerals are represented by carbonates (calcite and dolomite), iron (hydro-)oxides, galena, sphalerite, pyrite, chalcopyrite, Zn-Pb-S mineral, barite, baritocelestine, celestine, tetrahedrite, cassiterite, REE phosphate, etc. The regular distribution of mineral inclusions in peat is associated with the (bio)geochemical evolution of the environment. The formation of authigenic Zn, Pb and Sb sulfides is mainly confined to anaerobic conditions that exist in the eutrophic peat and basal sediments. The maximum amount of pyrite is associated with the interval of 225–250 cm, which is the zone of transition from basal sediments to eutrophic peat. The formation of carbonate minerals and the decreasing concentration of clay in the association with local sulfide formation (galena, sphalerite, chalcopyrite, stibnite) begins above this interval. The peak of specific carbonation appears in the 125–150 cm interval of the mesotrophic peat, which is characterized by pH 4.9–4.5 of pore water. Kaolinite is the dominant clay mineral in the oligotrophic peat. Gypsum, galena, chalcopyrite, sphalerite, and relicts of carbonate are noted in association with kaolinite. Changes in oxygen concentrations are reflected in newly formed mineral associations in corresponding intervals of the peat. This can be explained by the activity of microbiological processes such as the anaerobic oxidation of methane (AOM) and bacterial sulfate reduction (BSR), expressed in specific carbonatization (100–225 cm) and sulfidization (175–250 cm), respectively.

Vegetation history and the impact of tephra deposition during 7000 years based on pollen and tephra analysis of a Barasantou Bog sediment core, eastern Hokkaido, northern Japan

To estimate the impact of a volcanic eruption on vegetation, we conducted a field survey and collected peaty sediments and made pollen and tephra analysis from Barasantou Bog, in eastern Hokkaido, northern Japan. Using an electron probe micro-analyzer, we identified five tephra layers in the core: Ma-g (7.6 cal ka BP), Ma-e (5.5 cal ka BP), Ma-d (4.0 cal ka BP), Ta-c (2.5 cal ka BP), and Ko-c2 (AD 1694). When the peat began to accumulate again after deposition of the Ma-g tephra, the groundwater level of this area was very low, and Alnus, Poaceae, Thalictrum, Artemisia, and ferns dominated. Gradually, the groundwater level increased, and the condition of this wetland approached the present conditions, about 5.0 to 4.5 cal ka BP. Pinaceae conifers increased 2.5 cal ka BP. It is presumed that Picea glehnii and Abiesspecies formed wetland forests. Myrica gale and Alnus increased again, and grew to the edge of the wetland. At the same time, Quercus subgen. Lepidobalanus decreased and Betula increased. This trend might be due to the influence of human activity. The wetland vegetation changed from Thalictrum and Artemisia to Sanguisorba, and then from Sanguisorba to Menyanthes after the deposition of Ma-g tephra or after 2.5 ka BP. It was thought that the wetland changed from low moor to middle or high moor. A tephra layer tens of cm thick is not expected to affect pollen composition, and may have no clear impact on the surrounding vegetation. Sediment with a thickness of a few cm requires a deposition time of approximately 10 years; pollen analysis results are on the scale of the average vegetation change during that period. We conclude that short-term vegetation changes were not detected.

Postglacial relative sea‐level rise in the Limfjord region, northern Jutland, Denmark

A new core drilled at Nørrekær Enge, Løgstør, Denmark, shows terrestrial lake and bog sediments lying beneath 10 m of marine sediments. Pollen analysis, 14C dating and sedimentary observations show that these sediments relate to an ancient lake basin that was flooded when the rising sea levels reached 8.0 m b.s.l. This new study has allowed a review of previous data relating to shoreline displacement from the Limfjord region of northern Jutland, Denmark. Here we present a new shoreline displacement curve spanning the period between c. 11 700 and 7700 cal. a BP and built upon the Nørrekær Enge data and data from seven other boreholes and excavations from the Limfjord region. A previous shoreline displacement curve for this region suggested a very rapid relative sea‐level rise of 3 to 5 m 100 a−1 whereas this new curve suggests a much slower rise of around 1 m 100 a−1, similar to global rates.

Cirque Glacier on South Georgia Shows Centennial Variability over the Last 7000 Years

A 7000 year-long cirque glacier reconstruction from South Georgia, based on detailed analysis of fine-grained sediments deposited downstream in a bog and a lake, suggests continued presence during most of the Holocene. Glacier activity is inferred from various sedimentary properties including magnetic susceptibility (MS), dry bulk density (DBD), loss-on-ignition (LOI) and geochemical elements (XRF), and tallied to a set of terminal moraines. The two independently dated sediment records document concurring events of enhanced glacigenic sediment influx to the bog and lake, whereas the upstream moraines afford the opportunity to calculate past Equilibrium Line Altitudes (ELA) which has varied in the order of 70 m altitude. Combined, the records provide new evidence of cirque glacier fluctuations on South Georgia. Based on the onset of peat formation, the study site was deglaciated prior to 9900±250 years ago when Neumayer tidewater glacier retreated up-fjord. Changes in the lake and bog sediment properties indicate that the cirque glacier was close to its maximum Holocene extent between 7200±400 and 4800±200 cal BP, 2700±150 and 2000±200 cal BP, 500±150-300±100 cal BP, and in the 20th century (likely 1930s). The glacier fluctuations are largely in-phase with reconstructed Patagonian glaciers, implying that they respond to centennial climate variability possibly connected to corresponding modulations of the Southern Westerly Winds.

A chronology of post‐glacial landslides suggests that slight increases in precipitation could trigger a disproportionate geomorphic response

AbstractLarge, deep‐seated landslides are common throughout the south‐eastern San Juan Mountains of Colorado and New Mexico, but their timing and initiation are not well understood. Determining when the landslides occurred would aid in clarifying the mechanisms for initiating landslides in the region and would help us to understand post‐glacial landscape evolution. We studied seven pre‐historic landslides located within the Tertiary volcanic rocks of the San Juan Volcanic Field. The landslides range in area from ~0.8 km2 to ~11.3 km2 and most are located in areas that were previously mapped as having been ice‐covered during the last glaciation. Landslide deposits were dated using a variety of methods including surface exposure dating (chlorine‐36, 36Cl), radiocarbon dating of basal bog sediments and organic material buried in soils, and relative soil development. The resulting limiting ages range from approximately 14 ka to 2 ka and show that deep‐seated landsliding has occurred throughout the post‐glacial period. This broad range in ages is inconsistent with our initial hypothesis, which proposed that landslides were likely the result of debuttressing of glacial walls during glacial retreat. Furthermore, the timing of landslides does not seem to correlate with documented post‐glacial climatic shifts. Therefore, we conclude that landsliding in the region was the result of wetter than normal periods lasting months to years acting on weak bedrock preconditioned to failure and prepared by glacial debuttressing. Our findings suggest that the study area is likely still susceptible to deep‐seated landsliding and may become even more prone to large‐scale slope failure if future climate change increases precipitation in the San Juan Mountains. Copyright © 2017 John Wiley & Sons, Ltd.

How warm? How wet? Hydroclimate reconstruction of the past 7500 years in northern Carpathians, Romania

As natural and anthropogenic ecosystems are dependent on the local water availability, understanding past changes in hydroclimate represents a priority in research concerning past climate variability. Here, we used testate amoebae (TA) and chironomid analysis on a radiocarbon dated complex of small pond and peat bog sediment profiles from an ombrotrophic bog (Tăul Muced, northern Carpathians, Romania) to quantitatively determine major hydrological changes and July air temperature over the last 7500years.Wet mire surface conditions with a pH between 2.3 and 4.5 were inferred for the periods 4500–2700 and 1300–400calyrBP by the occurrence of Archerella flavum, Amphitrema wrightianum and Hyalosphenia papilio. Dry phases in mire surface conditions and a pH between 2.5 and 5 were inferred for 7550–4500, 2750–1300 and 0calyrBP–present by the dominance of Nebela militaris, Difflugia pulex and Phryganella acropodia. The quantitative reconstruction of mean July temperature based on the chironomid communities suggests low summer temperatures for the periods 6550–5600, 4500–3150 and 1550–600calyrBP, while periods of slightly higher summer temperatures were observed for 5600–4500, 3150–1550 and 100calyrBP–present. There is a generally good agreement between drier phases of the peat surface conditions with higher July temperature, suggesting that temperature may have been a controlling factor for water table fluctuation.Our quantitative reconstructions, among the first for central eastern Europe, show a relatively good agreement with other palaeohydrological studies from central eastern Europe, but contrast with others estimates from north-west Europe. Another important aspect of our study is that it provides valuable information on changes in local hydrology and the potential effect of the mean summer temperature over these changes.

The first 100 years of pollen analysis

In 1916, Swedish geologist Ernst Jakob Lennart von Post delivered a provocative lecture in Oslo, Norway, advocating the use of pollen grains in bog sediments as indicators of past vegetation and climate. The lecture spawned many applications and represents a landmark in multidisciplinary science.

Diversity of Fish and Mapping Distribution of Invasive, Banned and Protected Fish at Rawadanau Concervation Area Banten

Rawadanau Conservation Area has main function to take care of biodiversity. The research of fish diversity and Invasive Alien Species has been conducted. The research was conducted in August-September 2015. The aim is to show the value of community structures such as index of fish diversities, the similarities, dominances and alien species. We found nine species contain 198 fish, the details are 63 fish at Muara station, 73 fish at Jamungkal and 62 at Cibungur. The category of Biodiversity index showed low category, as follows 1.7306, 1.1146 and 1.2153. The category of similarity index showed low-middle category between 0.259786 – 0.417703. The details are 0.417703 at Muara Station (middle category and labil community); 0.259786 at Jamungkal Station and 0.294471 at Cibungur Station (Low Category and depressed community), dominancy index is in low category between 0.268-0.353, it is 0.268 at Muara Station, 0.353 at Jamungkal Station and 0.320 at Cibungur Station. The endemic fish are spotted gouramy, common snakehead, climbing gouramy, gondang snail and silver barb fish. Alien species are plecos, pomfret, carp and catfish. The water temperature 26-27 oC, pH between 5.76-6.16,water depth 150 s/d >200 m, brightness 53.3- 66.6 m, current speed 0.12-0.15 (m/s), DO 6-6.3 mg/l and bog sediment.

The presence of hydrogenotrophic methanogens in the inoculum improves methane gas production in microbial electrolysis cells

High current densities in microbial electrolysis cells (MECs) result from the predominance of various Geobacter species on the anode, but it is not known if archaeal communities similarly converge to one specific genus. MECs were examined here on the basis of maximum methane production and current density relative to the inoculum community structure. We used anaerobic digester (AD) sludge dominated by acetoclastic Methanosaeta, and an anaerobic bog sediment where hydrogenotrophic methanogens were detected. Inoculation using solids to medium ratio of 25% (w/v) resulted in the highest methane production rates (0.27 mL mL−1 cm−2, gas volume normalized by liquid volume and cathode projected area) and highest peak current densities (0.5 mA cm−2) for the bog sample. Methane production was independent of solid to medium ratio when AD sludge was used as the inoculum. 16S rRNA gene community analysis using pyrosequencing and quantitative PCR confirmed the convergence of Archaea to Methanobacterium and Methanobrevibacter, and of Bacteria to Geobacter, despite their absence in AD sludge. Combined with other studies, these findings suggest that Archaea of the hydrogenotrophic genera Methanobacterium and Methanobrevibacter are the most important microorganisms for methane production in MECs and that their presence in the inoculum improves the performance.

Identification of Anthropological Landscapes and Human Activity in Georgia in Correlation with Holocene Black Sea Level Fluctuations

The database of palynological studies of marine, lagoon, alluvial and bog sediments of the Black Sea coastline on the territory of Georgia includes 26 profiles of Holocene sediments. Analysis and synthesis of pollen diagrams allowed us to make a stratigraphic subdivision of Holocene sediments and reveal climatic fluctuations for the last 10 000 years. The most informative pollen spectra were those of marine formations with no gaps in sediment accumulation. Three main stages of climate warming have been revealed, reaching a maximum in the periods 6000-5500 BP, 3800-2400 BP and 1350-600 BP. Rather significant warming is indicated for the Middle Ages (7^th -11^th cent. B. C.). In all these periods the Black Sea level on the Georgian coast was some metres higher than previously. During climatic optima new cultures appeared in the Georgian archaeological record. Early agriculture penetrates not only into the middle mountain belt, but also into higher areas.