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Introduction: The increased adoption of proximal sensors has helped to generate peat mapping products: they gather data quickly and can detect the peat-mineral later boundary. A third layer, made of sedimentary peat (limnic layers, gyttja), can sometimes be found in between them. This material is highly variable spatially and is associated with degraded soil properties when located near the surface. Methods: This study aimed to assess the potential of direct current resistivity measurements to predict the maximum peat thickness (MPT), defined as the nonlimnic peat thickness, to facilitate soil conservation andmanagement practices at the field-scale. The results were also compared to a regional map of the MPT from a previous study used and also tested as a covariate. This study was conducted in a shallow (MPT = 8-138 cm) cultivated organic soil from Québec, Canada. The MPT was mapped using the apparent electrical conductivity (ECa) from a Veris Q2800, and a digital elevation model, with and without a regional MPT map (RM) as a covariate to downscale it. Three machine-learning algorithms (Cubist, Random Forest, and Support Vector Regression) were compared to ordinary kriging (OK), multiple linear regression, and multiple linear regression kriging (MLRK) models. Results and discussion: The best predictive performance was achieved with OK (Lin's CCC = 0.89, RMSE = 13.75 cm), followed by MLRK-RM (CCC = 0.85, RMSE = 15.7 cm). All models were more accurate than the RM (CCC = 0.65, RMSE = 29.85 cm), although they underpredicted MPT > 100 cm. Moreover, the addition of the RM as a covariate led to a lower prediction error and higher accuracy for all models. Overall, a field-scale approach could better support precision soil conservation interventions by generatingmore accuratemanagement zones. Future studies should test multi-sensor fusion and other geophysical sensors to further improve the model performance and detect deeper boundaries. [ABSTRACT FROM AUTHOR]

This paper presents the authors' research results from an analysis of intermediate foundations as well as slab and pile foundations in the context of soil consolidation. Looking at soil as a building material that changes its properties over time is very important from the point of view of the safety of construction, implementation, and operation of building structures. In addition, soil can be parameterized in such a way as to accurately describe its possible behavior under service loading. Of great interest is the phenomenon of consolidation, which is based on the reduction of soil volume over time under constant loading. This study explores existing piles and replicates soil conditions to understand individual and grouped pile behavior in combined pile–raft foundations (CPRF). To assess pile settlement from primary and secondary consolidation phases, 13 field measurements on concrete columns in gyttja clay were conducted. Analyzing data from these tests allowed engineers to accurately calibrate a numerical model. This calibrated model was instrumental in designing high-rise buildings, ensuring stability and safety. This study emphasizes the importance of understanding soil behavior, particularly consolidation phenomena, in optimizing foundation design and construction practices. [ABSTRACT FROM AUTHOR]

This paper presents the authors’ research results from an analysis of intermediate foundations as well as slab and pile foundations in the context of soil consolidation. Looking at soil as a building material that changes its properties over time is very important from the point of view of the safety of construction, implementation, and operation of building structures. In addition, soil can be parameterized in such a way as to accurately describe its possible behavior under service loading. Of great interest is the phenomenon of consolidation, which is based on the reduction of soil volume over time under constant loading. This study explores existing piles and replicates soil conditions to understand individual and grouped pile behavior in combined pile–raft foundations (CPRF). To assess pile settlement from primary and secondary consolidation phases, 13 field measurements on concrete columns in gyttja clay were conducted. Analyzing data from these tests allowed engineers to accurately calibrate a numerical model. This calibrated model was instrumental in designing high-rise buildings, ensuring stability and safety. This study emphasizes the importance of understanding soil behavior, particularly consolidation phenomena, in optimizing foundation design and construction practices.

The aim of this study is to characterize the current spatial distribution of three main phyla of phytoplankton (Cyanobacteria, Charophyta and Chlorophyta) from 77 Latvian lakes and ponds, analysed from modern surface sediment samples through a non-pollen palynomorph approach. The Pearson cross-correlation and the principal component analysis were applied to test the potential correlation of phytoplankton with climate (mean winter and summer temperature), water (pH), environmental (land use â forest, agriculture and urban) and sediment (organic and carbonate matter) variables. The results show the dominance of Chlorophyta in Latvian lakes and ponds. Cyanobacteria were dominant in sites closer to human-populated and recreation centres, including urban and agricultural land-use areas. In more turbid and polluted environments, Chlorophyta thrive today. Charophyta dominated in forested areas. Although Chlorophyta dominate in present-day waterbodies, the rather high relative proportion of Cyanobacteria draws attention to a potential threat. As the cross-correlation results indicate a negative correlation between Cyanobacteria and mean winter temperatures, in warmer climates Cyanobacteria can overtake other phytoplankton. The results of this study can be further used in lake and pond management.

We present the first record of Holocene fossil insect assemblages from Central Yakutia. A stratigraphic sequence in the locality within the Vilyuy River valley is a buried oxbow. The late Holocene water body inherited an impervious stratum from the late Pleistocene. The organic layer preserved rich fossil assemblages of macrofossils including insects and other invertebrates, plants, and charcoal. The ancient flora and fauna include species that are common in Yakutia as well as those that are rare and absent in the region. The most abundant finds are leech cocoons and bogbean seeds. The macrofossils of some insects were found along with remains of their host plants. Despite the absence of intensive human land use in the area, traces of fires were recorded. The oxbow represents the environment of a floodplain wetland that developed separately from the ecosystem of the adjacent sand dunes. [ABSTRACT FROM AUTHOR]

Human‐induced activities around Lake Lilaste in the central Latvian sandy coastal area have been reconstructed over a 1300‐year period. We use a combination of well‐established geoarchaeological research methods (14C dating, pollen, nonpollen palynomorphs, REVEALS modeling, diatoms, C/N ratio, magnetic susceptibility, loss on ignition) to study the human impact on the environment. Historical context aids focus on records of resource (e.g., timber) exploitation in the area. The continuous record of human indicator pollen and agricultural landscape suggests this area was suitable for habitation well before the studied time period, likely due to the ecosystem services it provided. Our proxy‐based study, combined with historical background, reveals a significant human impact on the terrestrial environment since the 14th century. Deficiency of trees in the northern outskirts of Riga during the 17th–19th century was likely. Anthropogenic activity has led to both deforestation and change in species composition. Our paleo records indicate recognizable human‐driven legacy in current seacoast landscape. [ABSTRACT FROM AUTHOR]

As part of paleogeographic studies on the Curonian Spit (geological section GS 024), a coastal section was studied from the sea in the area of the village of Lesnoy in the place where relict lagoon oozes come out. The granulometric, chemical, and mineral compositions of slope sands were studied for the first time. Heterogeneous conditions for the formation of sand strata were confirmed. A high probability of a secondary change in the composition of sediments as a result of weathering processes was revealed. The results of the study indicate a gradual advance of sand deposits on the coastal part of the lagoon, which began about 10 ka ago. Differentiation of the sand stratum into lower and upper parts with respect to an interlayer marker of coarse-grained sand identified in the section may reflect different stages of generation of the sand stratum: from an alleged shallow-water swell formed during sea level rise to beach and eolian sands. [ABSTRACT FROM AUTHOR]

Continuous sediment cores H1 (11.0 m long) and H2 (8.5 m long), collected from Swan Lake, in the Nebraska Sandhills (USA), contain a sandy silt interval between overlying lake gyttja and underlying marsh peat. The marsh peat is a 3-m-thick layer in core H1 and a 1.5-m-thick layer in core H2, with basal ages of ca. 4790 and 4710 cal yr BP, respectively. Peat samples contain up to ~ 61% organic matter (OM) and lack CaCO3 and opal phases. Gyttja extends from 7.6 to 0 m in core H1 and from 6.6 to 0 m in core H2, with estimated basal ages of 3480 and 3530 cal yr BP, respectively. Gyttja samples contained stratigraphically fluctuating relative amounts of OM, precipitated CaCO3, biogenic (ostracod) CaCO3, and diagenetic mineralogical aggregates with CaCO3-opal-A-opal-CT-quartz or opal-A-quartz. OM content in the gyttja ranged from 15.1 to 32.1% and bulk CaCO3 content ranged from 13.5 to 34.6%. Mineralogical aggregates appeared after ~ 2630 cal yr BP in core H1 and after ~ 2590 cal yr BP in core H2, whereas ostracods were found only after ~ 1250 and ~ 1840 cal yr BP in the two cores, respectively. The discrepancy in the timing of ostracod occurrence may be related to environmental differences at the two locations, which are ~ 100 m apart. The sandy silt interval (0.4 m thick) between the peat and overlying gyttja accumulated between ~ 3700 and 3500 cal yr BP. It has relatively low OM (10.3–15.1%) and calcite content (0–6.1%) and no ostracods or mineralogical aggregates. The sandy silt interval possessed a high clastic content (~ 88%), with up to 3.2% Fe, 0.25% Ti, 108 ppm Rb, 105 ppm Zr, 65.5 ppm Cr, 36.6 ppm La, 10 ppm Th, and 2.6 ppm U. The clastic particles and associated metals were deposited by eolian processes during a dry and windy climate episode at the onset of the late Holocene in the Sandhills region. [ABSTRACT FROM AUTHOR]

We present the first record of Holocene fossil insect assemblages from Central Yakutia. A stratigraphic sequence in the locality within the Vilyuy River valley is a buried oxbow. The late Holocene water body inherited an impervious stratum from the late Pleistocene. The organic layer preserved rich fossil assemblages of macrofossils including insects and other invertebrates, plants, and charcoal. The ancient flora and fauna include species that are common in Yakutia as well as those that are rare and absent in the region. The most abundant finds are leech cocoons and bogbean seeds. The macrofossils of some insects were found along with remains of their host plants. Despite the absence of intensive human land use in the area, traces of fires were recorded. The oxbow represents the environment of a floodplain wetland that developed separately from the ecosystem of the adjacent sand dunes.

A complex of dislocations is described (extended gently dipping faults with a displacement of up to 1 m, dipping towards the center of the lens, steep faults with displacements of 5–20 cm), liquefaction structures (angular pseudonodules of sands in silts), near fault and near-strike-slip fault folds in the section of a large lens of the Mikulinskiy lacustrine–bog sediments (interbedded silt with a horizon of peat and clayey gyttja) of the aseismic region of the Russian Plate (Klin–Dmitrov ridge) in order to compare them with similar structures of the Baltic Shield, the seismogenicity of which is being discussed. It has been shown that the sequence was not subjected to periglacial phenomena such as glaciotectonics, glaciokarst, cryogenic deformations, the presence of which and pseudomorphism along polygonal-veined ice was noted only in the roof of the Mikulinskiy interglacial complex. A model is proposed for the formation of dislocations as a result of slumping of a silt layer with uneven subsidence of the underlying layers of peat sediments, which have been strongly compacted during lithogenesis, which explains the features of the kinematics of faults. The results showed that the dislocations of the Mikulinsky complexes of the Dmitrov quarry do not fundamentally differ from similar structures of the Baltic Shield, which confirms their lithogenic or exogenic (rather than seismotectonic) genesis in both regions. The differences in the dislocation complexes of the two regions are in the different sequence of formation of liquefaction and faults structures: in the Dmitrov section, they were formed synchronously, in the sections of the Baltic Shield, asynchronously. [ABSTRACT FROM AUTHOR]

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Copyright of Journal of Agriculture & Nature / Kahramanmaraş Sütçü İmam Üniversitesi Tarım & Doğa Dergisi is the property of Kahramanmaras Sutcu Imam Universitesi and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)