In this paper we present the first ecological data of Indochinese freshwater pearl mussel, Margaritifera laosensis populations. We also provide a comparative study of the ecology of this tropical species with populations of other Margaritiferidae. We conducted surveys in ten tributaries of the River Nam Ou (Middle Mekong Drainage, Northern Laos). Reproductively viable populations were found only in the Nam Long and Nam Pe rivers, which are two of the only three known viable populations of this species in the world. The habitats of M. laosensis include mountainous oligotrophic rivers with circumneutral pH. Optimal mesohabitats are riffles and runs with a median depth of 0.2 m and median current velocity of 0.3 ms⁻¹. Pearl mussels were more common in gravel and fine gravel riverbed substrates. Surveys revealed 252 specimens, but only 78 (31.0%) were alive. The largest mussels observed were 110 mm in length and only 11–12 years of age. The presence of smaller-sized mussels indicates recent recruitment in both populations. The most significant threats to M. laosensis populations are harvest by local people and land development in the River Nam Ou Basin.

Surface Kastanozem of the Lower Volga area was first studied as a part of the pedocomplex, with the lower part (148–160 cm) formed in Early Khvalynian Chocolate clays (13–15 ka), the middle part (100–148 cm) in a mixed clay-loess sediment sand, and the upper part (0–100 cm) in loess. This resulted from local aeolian transport, with the source material derived from the rewinding of marine sediments. They are enriched in aggregates of Chocolate clays and glauconitic grains of a fine sand-course silt size and have similar contents of clay minerals. The high salinity of similar types evidences marine genesis for both Chocolate clays and source material for loess sediments. Clay fragments of a sand and silt size are responsible for the heavy texture and high gypsum content of loess. The study of soils with the focus on micromorphology and clay mineralogy allows the identification of the complex character of a shift from marine to sub-areal sedimentation. This shift was accompanied by short breaks in sedimentation, allowing the development of synlithogenic soil horizons of Late Khvalynian, after-Khvanynian, and Boreal time. The features of shallowly buried soil horizons confirm increased aridity after the last deglaciation. Surface Calcic Kastanozem is a full Holocene soil reflecting the present environment. However, it is deeply influenced by shallow buried soil horizons and Chocolate clays.

The purpose of this study was to investigate the applicability of semiautomatic segmentation methods for obtaining and evaluating morphometric parameters of soil aggregates in artificially prepared loose samples in soil thin sections. The object of the research is typical arable Chernozem. The aggregates were separated by wet sieving method from loose sample of upper 10 cm of the plowing horizon after erosion by a model shallow water flow on a large erosion tray. The aggregates, loosely scattered on the glass and fixed with polyester resin, were used to produce the thin sections. Images of the thin sections were taken under a polarizing microscope and then were processed using two methods compared: Adobe Photoshop + CTan and Thixomet Pro. Data on morphometric parameters of aggregates were obtained: the shape factor, the degree of roundness and the coefficient of aggregate surface roughness. The convergence of the results obtained using Photoshop + CTan by three researchers was evaluated by comparing samples using the Student's test and the Mann-Whitney test. The convergence of the averaged results obtained using Photoshop + CTan and the results obtained using Thixomet Pro was evaluated using the Mann - Whitney test. No significant differences were found between the parameters of the same aggregates obtained using a combination of Adobe Photoshop and CTan programs by different researchers. No significant differences were found between the parameters of the same aggregates obtained by the compared methods. So, one can conclude that the reliability of determining the morphometric parameters of soil aggregates using Thixomet Pro is comparable to the reliability of results when working with images of sectionsin CTan after binarization in Adobe Photoshop. The method of obtaining data on morphometric parameters of soil aggregates using Thixomet Pro completely eliminates the possibility of subjective error, shows a high degree of automation, reproducibility and reliability of the results obtained, and is faster.

The Sukhaya Mechetka is the most important Middle Paleolithic site in the Eastern Europe. The paper presents the analysis of the section, including its cultural layer, in the context of stratigraphy and paleogeography of the Lower Volga River region. The structure of the section represents 11 main stages of sedimentation and paleogeographic evolution of the site territory, which are closely related to global and regional changes in the climate and the level of the Caspian Sea. The base of the section reflects the stage of a river existence on the territory of the site that flowed into the Volga River estuary, formed by the Early Khazarian transgression of the Caspian Sea at the end of the Middle Pleistocene (MIS 6). A long continental period of evolution under multi-directional climate fluctuations of different amplitudes from the Mikulino interglacial (MIS 5e) till the Late Valdai glacial epoch (MIS 2) is reflected in the middle part of the section. The Late Khazarian and Hyrcanian transgressive basins (MIS 5), as well as the Paleo-Khvalynian stage (MIS 3) of the Caspian Sea did not reach the latitude of Sukhaya Mechetka. The stage of Early Khvalynian transgression (MIS 2, 16 190 ± 200 years ago) during the degradation of Ostashkovo glaciation is expressed in the upper part of the section. Three paleosoils have been found that reflect the warming periods of the MIS 5 stage and are related to its 5e, 5c and 5a sub-stages. The middle paleosoil contains a cultural layer assigned to the Micoquian/KMG community of Northern Eurasia. The climate was moderately warm during the Neanderthal settlement of the territory, steppe landscapes dominated the interfluve, and the forests grew in the balka. The Hyrcanian transgression of the Caspian Sea with an estuary in the Volga River valley predetermined a high erosion basis and the formation of a balka with a wide bottom and gentle banks. A permanent fresh watercourse attracted mammals which were an object of hunting for ancient men. All this, obviously, became a basis for the organization of settlement in the Sukhaya Mechetka balka. Correlation of the section with detailed studied loess-soil sections of the Lower Volga River region makes it possible to determine the age of its cultural horizon in between 97-110 thousand years ago.

The soil cover of semi-desert territories is sensitive to modern climatic changes, responding to a change in the composition of soil complexes. Soil microstructure features reflect minor changes in microrelief or fluctuations in the level of groundwater. This property of soil microstructure to memorize soil formation conditions is used for subsequent characterization of changes in long-term climatic trends. But in semi-desert climates, it can be used as an indicator of short-term weather series. This article presents data collected on the territory of the Caspian Depression in the Dzhanybek Research Station of the Institute of Forest Science RAS. The soil cover of the studied site of this station is represented by a semi-desert, two-component meadow-steppe Solonetzic soil complex that strictly follows the elements of the local microtopography. The height range between the studied pits is 8 cm. The dataset includes micromorphological photographs of the state of the soil complex in 2005. This year is an initial moment for modeling soil properties at the present day taking into account the changed weather parameters. The weather data was collected between February 2005 and June 2021. It includes daily, decadal and monthly data related to air temperature, relative air humidity, wind speed and precipitation, soil temperature and depth of freezing (thawing) of the soil, snow cover depth. The measurement methods did not change throughout the entire observation period, which makes it possible to use the data to correct forecasts of the response of drylands to modern climatic changes with the subsequent verification of models in the field at present.