This paper presents the results of studying the ash content of twig and leaf debris from forest plants of primary midmountain tropical forests of Central Vietnam (Bidoup Núi Bà National Park) in order to identify and clarify the elements that enter the soil during their decomposition. The difference in the ratio of twig and leaf debris in mortmass samples collected in different landscape conditions is shown. At the same time, the influence of periodical and stagnant moisture conditions on the conduct of migratory soil processes is considered. The sampling points of the twig and leaf debris correspond to the locations of the soil catena within the structural ridge and its top, slope, and foothill. This allows us to relate the results obtained on the elemental composition of the twig and leaf debris to the geochemical migration of chemical elements in different geochemical landscape conditions, from automorphic to accumulative. An attempt has been made to establish the volumes of matter migrating from the mortmass into the soil together with the aqueous solution. Differences in the accumulation of ash elements in the twig and leaf debris depending on the position in different landscape conditions are revealed. The composition of elements entering the soil with twig and leaf debris and involved in geochemical migration is established, and the contribution of leaves and twig debris to the accumulation and migration of elements under different moisture conditions is evaluated. The dependence of geochemical migration processes on the position of the elementary geochemical landscape facies in the catena is pointed out, which manifests itself in a change not only in the total ash content of the twig and leaf debris, but also in the ratio of ash content of twig debris to that of leaf debris.

Rapid urbanization and anthropogenic activities have led to a significant deterioration of air quality, adversely affecting human health and ecosystems. The study of transboundary river basins, where air pollution is exacerbated by political and socio-economic factors, is of particular relevance. This paper presents the results of an analysis of the spatiotemporal distribution of pollutants (Aerosol Index (AI), Methane (CH₄), Carbon Monoxide (CO), Formaldehyde (HCHO), Nitrogen Dioxide (NO₂), Ozone (O₃), Sulfur Dioxide (SO₂)) in the ambient air within the Orontes River basin across Lebanon, Syria, and Turkey for the period 2019–2024. The research is based on satellite monitoring data (Copernicus Sentinel-5P), processed using the Google Earth Engine (GEE) cloud-based platform and GIS technologies (ArcGIS 10.8). The dynamics of population density (LandScan) and the impact of military operations in Syria on air quality were additionally analyzed using media content analysis. The results showed that the highest concentrations of pollutants were recorded in Syria, which is associated with the destruction of infrastructure, military operations, and unregulated emissions. The main sources of pollution were: explosions, fires, and destruction during the conflict (aerosols, CO, NO₂, SO₂); methane (CH₄) leaks from damaged oil and gas facilities; the use of low-quality fuels and waste burning. Atmospheric circulation contributed to the eastward transport of pollutants, minimizing their spread into Lebanon. Population density dynamics are related to changes in concentrations of pollutants (e.g., nitrogen dioxide). The results of the study highlight the need for international cooperation to monitor and reduce air pollution in transboundary regions, especially in the context of armed conflicts. The obtained data can be used to develop measures to improve the environmental situation and protect public health.

The concentrations of 18 chemical elements were determined in the upper soil horizons within the landscapes of river basins in the Eastern Caucasus, using the Ulluchay, Sulak, Sunzha, Samur, Shuraozen (Russia), Karachay, and Atachay (Azerbaijan) rivers as case studies. This research aims to provide an ecological and geochemical assessment of soil conditions in the mountain river basins of the Eastern Caucasus. The ecological status of the soils is largely governed by elevated concentrations of such elements as Zn, Ni, Cu, Mo, As, and Cr, which exhibit both accumulation tendencies and potential toxicity. Environmentally unfavorable areas were identified through an integrated scoring assessment that incorporates the values of four ecological and geochemical indices: the modified contamination factor (mCf), the Pollution Load Index (PLI), the Potential Ecological Risk Index (PERI), and the total contamination index (Zc). According to each index, more than half of the study area is classified as uncontaminated. Low PLI values were recorded for 54% of the sampling sites, and low mCf values for 63%. Based on PERI and Zc, 82% of the sampling sites are categorized as uncontaminated. The integral scoring assessment enabled the delineation of more than a dozen environmentally unfavorable areas, with the highest concentrations observed in the Atachay and Karachay basins, spatially extensive in the Sunzha basin. The formation of environmentally unfavorable zones in terms of soil contamination is primarily driven by natural factors, including lithological conditions, climatic features, complex topography, and the directions of waterborne and mechanical migration. Anthropogenic factors contribute to a lesser extent to the development of high-contamination zones and exert only localized influences near major settlements. The results can be applied to mitigate public health risks and to promote sustainable development of mountain river basins. Targeted measures are proposed for the sustainable management of contaminated areas, including restrictions on agricultural activities and the use of drinking water sources.

Studying the response of forest ecosystems to climate change is one of the urgent tasks of modern ecology. Regional manifestations of global climate change lead to special reactions of forest ecosystems. The main source of energy for all processes in ecosystems is solar radiation. It starts all the processes of transformation of matter, energy and information in the ecosystem. A change in its income leads to a restructuring of the ecosystem functioning system. For the Crimean Peninsula today the response of forest ecosystems to climate change remains poorly studied. This determines the relevance and purpose of this work. On the base of the landscape-typological map of the Crimean Peninsula, open reanalysis databases, and GIS modeling, the elements of the radiation balance of the oak forest ecosystems of the Crimean peninsula are estimated under the conditions of modern climate changes. The basic laws of the radiation balance formation of oak forest ecosystems and the features of its interannual dynamics are shown.

Terrestrial vegetation cover is a critical component of the global carbon cycle, annually assimilating a substantial fraction of anthropogenic CO₂ emissions. However, regional estimates of gross primary production (GPP) and net primary production (NPP) remain insufficiently studied, especially for ecologically sensitive areas such as the sub-Mediterranean landscapes of southeastern Crimea. The aim of this study is to calculate and map the spatio-temporal distribution of GPP and NPP across southeastern Crimea over the period 2001–2025 using Earth remote sensing data and geoinformation modeling. This study employed MODIS products (MOD17A2H collection 061) processed in the Google Earth Engine cloud platform, together with temperature and precipitation data (ClimateEU, CHIRPS). Statistical analysis included calculation of the carbon use efficiency (CUE) coefficient and correlation analysis. The results show that the mean GPP for southeastern Crimea is 1.13 kg C/m² and the mean NPP is 0.61 kg C/m², which exceed global average values. Maximum productivity is characteristic of natural forest communities (sessile oak, beech and juniper forests), whereas anthropogenically transformed landscapes (agricultural land, urban coenoses) exhibit the lowest values. The mean CUE is 0.54, with the highest values (0.63–0.66) recorded for agrocoenoses and steppes, and the lowest (0.49–0.57) for forests. A positive correlation between productivity and precipitation and a negative correlation with air temperature were identified, especially for forest ecosystems. This study fills a gap in regional primary productivity assessments and can serve as a basis for ecosystem monitoring under climate change and anthropogenic pressure.

Expeditionary studies of the functioning of landscapes of mid-mountain monsoon (including fog) forests have been being conducted within the landscape and ecological station in the territory of the Bidoup-Nui Ba National Park and the adjacent Hon Giao since 2018 and are currently underway. One of the research objectives is to clarify the biogeochemical migrations of the material composition of soils in the “leaf debris–soil” system. We have consistently studied natural objects for their material composition as well as the intensity and rate of involvement of chemical elements in physicochemical migration processes in the “leaf debris–soil” system. Our findings indicate an active influx of a select group of examined elements (Se, Pd, Ag, Cd, Sn, Bi), particularly Bi, Pd, Se, and Cd, through the leaf debris and the detachment of aboveground plant organs, warranting their integration into organogenic soil horizons. Subsequently, lateral migration (Pd, Cd, Se) ensues. Slope processes within subordinate landscape facets, in addition to soil moisture and aeration processes, contribute to the subsequent redistribution of elemental volumes introduced into organogenic soil horizons.