Search Results (25)

This study investigated carbon sequestration potential in reforesting agricultural lands with prevalence of Scots pine (Pinus sylvestris L.) in the “Nasibash” site of the Eurasian Carbon Polygon, located in the Republic of Bashkortostan, Russia. The research focused on analyzing carbon stocks in different ecosystem components (tree stand, herbaceous layer, litter, and soil) across various stages of succession, including fallow land, hayfield, and four stages of Scots pine reforestation. We found that needles during the first stage of succession were characterized by the highest carbon sequestration, while the lowest was in underground phytomass (roots). The tree stand exhibited a higher potential for carbon sequestration in stem wood, branches, and needles compared to other components. The highest carbon accumulation in the tree layer was observed in the stem phytomass at the fourth stage of reforestation, while the highest phytomass accumulation in the herbaceous layer was in the root mass at the fourth stage of succession. The study revealed that the highest organic carbon content in the topsoil layer was observed in areas dominated by herbaceous vegetation, with a decrease in carbon content as the stage of succession increased. The highest carbon content was found in tree pines at the first stage of succession. The research highlighted the importance of considering conversion factors for different stages of reforestation, as the average carbon content in vegetation was 20% higher than the approved conversion factors for young tree stands. Overall, the study demonstrates the significant potential of Scots pine reforestation on former agricultural lands for carbon. The findings suggest that these territories play a decisive role in future environmental and climate projects, contributing to the decarbonization efforts. Full article

The forests of the boreal biome, which perform an important climate-regulating function, are the most susceptible to forest fires. An important task is to obtain quantitative estimates of carbon (C) losses of forest ecosystems under different fire damage scenarios, as well as the possibility of such estimates based on remote sensing data. Our study provides comprehensive field data on C stocks in pools of plant phytomass and necromass, forest litter, and ground cover for a vast area of boreal forests in the Russian Far East. We studied forests of the larch formation that have been affected by fires of varying intensity. The severity of the fires was assessed based on differenced Normalized Burn Ratio (dNBR). The variation in C pools depending on the strength of the fire is shown. We did not find a relationship of C stocks with the dNBR in the forests in the south of the study area that might have caused the rapid change of species during post-fire recovery. In the northern part of the area, there is a trend of a decrease in plant phytomass with an increase in dNBR (R² = 0.78). The proportion of dead standing wood share in the total C stock increases with increasing fire severity (R² = 0.63). The maximum and average C stocks in the litter were 10.6 and 3.9 t C ha⁻¹, respectively; coarse woody debris contained 8.7 and 2.0 t C ha⁻¹; carbon stocks in living ground cover were 1.2 on average and reached 4.7 t C ha⁻¹. Our study shows that dNBR can serve as a good predictor of the C stock of phytomass after a fire in the northern part of the Far East region, which opens up opportunities for approximate quantitative remote estimates of C losses. Full article

The growth of a city causes a complex of problems related to the increase in the pollution of the urban environment and the shortcomings in its improvement. The territory of the modern city is characterized by the highest man-made loads on the natural environment. The main problems are the low level of green areas, as well as the reduction in trees in many areas, which does not allow the city residents to live comfortably. Currently, Earth remote sensing methods using the vegetation index (NDVI) are one of the dominant means of assessing the condition. In this regard, the purpose of this study is to assess the ecological condition of the green zone in the city of Aktobe. To solve this problem, complex assessment was carried out, including statistical data analysis and the processing of satellite images by calculation of the NDVI for green areas and their mapping. The article analysis lies in the field of development and landscaping of the urban environment of Aktobe. A description of the current state of the system of green areas in the city was provided. On the basis of the data of remote sensing of the earth, the spatial features of the separate classes of the total phytomass of green plants within the city of Aktobe and the spatial features of the territorial zones of the city were determined during the differentiation of green plantings. A study of the dynamics of changes in the vegetation cover index (NDVI) during 2010, 2016, and 2023 allowed us to identify trends in the development of green spaces and their changes over time due to city growth and other factors. The data obtained as a result of the research can be used in the justification of urban planning decisions, landscape planning of the ecological infrastructure of the city, and optimization of landscaping systems. Full article

The state of meadow vegetation in areas with different ages of experimental spring burnout (from 1 to 12 years ago) was studied in the Tomsk region for 3 years. On experimental plots of 1 m² and 100 m² (small- and middle-scale levels, respectively), the dynamics of species richness, total projective cover of vegetation, and aboveground phytomass reserves were characterized, and the structure of communities was analyzed. It was revealed that a single fire in the spring significantly reduces species richness for small-scale plots and increases the total projective cover for middle-scale plots. Structural differences from control plots can be traced from 1 to 4 years for different characteristics. The effects of fire are more prominent for small-scale plots. To suppress tree growth and maintain the existence of meadows, grass fires seem to be a less effective practice than mowing. At the same time, the results obtained potentially allow us to consider prescribed burning as a tool for maintaining the stability of meadow plant communities in the south of Western Siberia, preventing them from becoming overgrown with tree undergrowth, in cases with a controlled frequency of burning and the use of appropriate fire safety measures. Full article

The topicality of our research topic is justified by the significant change in traditional grassland management in the grassland areas of the Pannonian Basin. Due to several factors, the proportion of fallow grassland, and in parallel of over-exploited pastures, is continuously increasing. In the medium term (11 years), the effects of fallowing (Z), annual mowing (M), mowing and grazing (meadow treatment M + G), and permanent overgrazing (OG) as treatments on the population structure of grassland plants were investigated in a semi-natural grassland community in the Solonyec soil. It was found that the lowest degradation rates in the studied grassland biotope were obtained for the treatment presenting the utilisation pattern of mowing the main grassland phytomass followed by sheep grazing of the coltgrass. The highest degradation levels, which threatened the condition of the grassland community, were measured for the treatment presenting overgrazing with sheep at the end of the experimental period. Full article

Currently, studies investigating the carbon balance in forest ecosystems are particularly relevant due to the global increase in CO₂ content in the atmosphere. Due to natural reforestation over the past 25–30 years, birch (Betula pendula Roth.) forests were extensively grown and established on abandoned agricultural lands in Bashkir Cis-Ural (Republic of Bashkortostan, Russia). The significant positive aspect of reforestation on fallow lands is the carbon sequestration that takes place in the tree phytomass, especially at the growth stage of stand formation. The aim of this article is to test the approach of using a UAV-mounted LiDAR camera to estimate the phytomass and carbon stocks in different-aged birch forests growing on abandoned arable lands in Bashkir Cis-Ural. The methodology was developed using 28 sample plots, where the LiDAR survey was performed using a DJI Matrice 300 RTK UAV. Simultaneously, the stand characteristics and phytomass of stem wood were also estimated, using traditional methods in the field of forest science. The regression equations of phytomass dependence on stand characteristics at different stages of reforestation were constructed using data obtained from LiDAR imagery. It was shown that the above-ground tree biomass could be precisely estimated using the index obtained by multiplying the number of trees and their average height. A comparison of the data obtained using traditional and LiDAR survey methods found that the accuracy of the latter increased in conjunction with stand density. The accuracy of estimation ranged from 0.2 to 6.8% in birch forests aged 20 years and over. To calculate carbon stocks of the above-ground tree stands, the use of regional conversion coefficients is suggested, which could also be applied for the estimation of carbon content in trunk wood and leaves. An equation for the calculation of above-ground biomass carbon stocks of birch forests on abandoned arable lands is proposed. Full article

In this study, we evaluated the impact of brown seaweed extract (Ecklonia maxima) on the morphology and physiology of three different plant species. We conducted experiments using two types of fertilizers: an artificial fertilizer (0.1 g/L) and a biological extract of brown seaweed (Ecklonia maxima) at two concentrations (C1 at 1 mL/L and C2 at 2.5 mL/L). For melon, the application of C1 resulted in significant improvements in photosynthesis parameters, total chlorophyll content, and overall plant growth. When C2 was applied, it further enhanced these parameters, leading to a notable increase in shoot phytomass. In the case of cucumber, C1 led to increased resource allocation towards stems and leaves. Conversely, C2 increased the number of green leaves and contributed to higher shoot phytomass. For tomato plants, the application of C1 resulted in a slight increase in photosynthesis, but it did not significantly impact leaf growth. On the other hand, C2 induced a modest increase in photosynthesis, chlorophyll content, and root growth. In summary, our findings indicate that brown seaweed extract has a discernible influence on the physiology of the studied plants. However, the specific effects on resource allocation largely depend on the plant species and the concentration of the extract applied. Full article

The productivity of water meadows was studied in the middle stream of the Ob River by direct in situ measurements of the live and dead components of phytomass/biomass, the features of the active layer in natural ecosystems, and the patterns of plant organic matter and productivity (NPP) in different plant communities, micro-landscapes, and underlying soils. The study was conducted across different ecosystems along two profiles in the floodplain: (i) in the conditions of haymaking and (ii) in all natural ecosystems. The study revealed drastic changes in floristic composition at two profiles (catenas) both in the structure of plant communities and in productivity/NPP at different levels of the floodplain. The maximum diversity of vegetation was found in pristine natural ecosystems. Haymaking leads to an increase in the part of perennial turf grasses and sedges and decrease in the part of motley grasses. The maximum stocks of above-ground biomass (1450 g/m²) and below-ground biomass (3380 g/m²) were found in topographic depressions dominated by sedges. Haymaking causes pressure on the formation of root systems in dry and wet (swampy) meadows, which in turn leads to a decrease in the below-ground component of plant biomass. The total stock of plant phytomass/biomass increases from the upper points to the lower points in the floodplain profile: from 2991 to 4565 g/m² with haymaking and from 3370 to 4060 g/m² across the natural ecosystems. The NPP decreases by 12% in the upper and by 5% in the middle parts of the catena under haymaking, but it does not change in the lower part of catena as compared to all natural ecosystems. Full article

This experiment evaluated the effects of various vermicompost amounts (0%, 10%, 20%, 25%, and 50%) of the total weight of the mixture of soil and vermicompost) and red worms (0, 10, and 20 individuals/pot) on carrot phytomass and macroelements concentration when applied to soil. Increasing the quantity of vermicompost (Vc) raised the weight of carrot roots and leaves. When we increased the dose of Vc, differences in phytomass growth were diminished gradually. Fifty percent of Vc in the soil did not have a negative impact on the formation of carrot roots and leaves. Vc increased the water content in roots and decreased it in leaves. Earthworms (EWs) in soil increased the weight of both carrot roots and leaves. The positive impact of EW on roots and leaves was higher when the vermicompost content in the soil was lower. EWs showed positive effects on the potassium concentration in whole carrot phytomass. Both EWs and Vc increased the value of the tetanic ratio in the carrot roots, which lowers their quality. EWs showed positive effects on the potassium concentration in whole carrot phytomass. Relationships found between K × Ca and Mg × S were antagonistic. Positive dependencies were detected between the carrot root yield and N, P, K concentration in both leaves and roots. Full article

Pig slurry (PS) has been used as soil fertilizer due to its nutrient and organic matter contents, which may improve soil nitrogen, carbon, and sulfur stocks. The objective of this work was to evaluate the best PS dose that favors the increase in dry matter production and carbon (C), nitrogen (N), and sulfur (S) contents and stocks after applications of PS to soils with Tifton-85 for six years. The experiment was conducted in a randomized block design with four replications, in a hay-producing area under a clayey Typic Hapludox in southern Brazil. The treatments consisted of annual applications of organic and mineral fertilizers at rates based on their N contents, using PS (100, 200, 300, and 400 kg ha⁻¹) and urea (200 kg ha⁻¹), and a control without N application. Samples of the soil in 0–5, 5–10, and 10–30 cm layers were collected in March 2019 and evaluated for soil bulk density and N, C, and S contents and stocks. The Tifton-85 dry matter production was evaluated using samples from three cuts carried out between 2012/2013 and 2017/2018 agricultural years. The applications of increasing doses of PS in Tifton-85 pastures over six years increase linearly the dry matter and soil organic C, N, and S stocks in the 0–30 cm layer. The PS rate equivalent to 100 or 200 kg ha⁻¹ of N is recommended for increasing soil C, N, and S stocks, since it resulted in C, N, and S stocks equal to or higher than the control and mineral (urea) treatments. Full article

We studied two medium size pristine rivers (Taz and Ket) of boreal and subarctic zone, western Siberia, for a better understanding of the environmental factors controlling major and trace element transport in riverine systems. Our main objective was to test the impact of climate and land cover parameters (permafrost, vegetation, water coverage, soil organic carbon, and lithology) on carbon, major and trace element concentration in the main stem and tributaries of each river separately and when considering them together, across contrasting climate/permafrost zones. In the permafrost-bearing Taz River (main stem and 17 tributaries), sizable control of vegetation on element concentration was revealed. In particular, light coniferous and broadleaf mixed forest controlled DOC, and some nutrients (NO₂, NO₃, Mn, Fe, Mo, Cd, Ba), deciduous needle-leaf forest positively correlated with macronutrients (PO₄, P_tot, Si, Mg, P, Ca) and Sr, and dark needle-leaf forest impacted N_tot, Al, and Rb. Organic C stock in the upper 30–100 cm soil positively correlated with Be, Mn, Co, Mo, Cd, Sb, and Bi. In the Ket River basin (large right tributary of the Ob River) and its 26 tributaries, we revealed a correlation between the phytomass stock at the watershed and alkaline-earth metals and U concentration in the river water. This control was weakly pronounced during high-water period (spring flood) and mostly occurred during summer low water period. Pairwise correlations between elements in both river systems demonstrated two group of solutes—(1) positively correlated with DIC (Si, alkalis (Li, Na), alkaline-earth metals (Mg, Ca, Sr, Ba), and U), this link originated from groundwater feeding of the river when the labile elements were leached from soluble minerals such as carbonates; and (2) elements positively correlated with DOC (trivalent, tetravalent, and other hydrolysates, Se and Cs). This group reflected mobilization from upper silicate mineral soil profile and plant litter, which was strongly facilitated by element colloidal status, notably for low-mobile geochemical tracers. The observed DOC vs DIC control on riverine transport of low-soluble and highly mobile elements, respectively, is also consistent with former observations in both river and lake waters of the WSL as well as in soil waters and permafrost ice. A principal component analysis demonstrated three main factors potentially controlling the major and TE concentrations. The first factor, responsible for 26% of overall variation, included aluminum and other low mobile trivalent and tetravalent hydrolysates, Be, Cr, Nb, and elements strongly complexed with DOM such as Cu and Se. This factor presumably reflected the presence of organo-mineral colloids, and it was positively affected by the proportion of forest and organic C in soils of the watershed. The second factor (14% variation) likely represented a combined effect of productive litter in larch forest growing on carbonate-rich rocks and groundwater feeding of the rivers and acted on labile Na, Mg, Si, Ca, P, and Fe(II), but also DOC, micronutrients (Zn, Rb, Ba), and phytomass at the watershed. Via applying a substituting space for time approach for south-north gradient of studied river basins, we predict that climate warming in northern rivers may double or triple the concentration of DIC, Ca, Sr, U, but also increase the concentration of DOC, POC, and nutrients. Full article

Mature forest ecosystems are the most considerable reservoir of organic carbon (OC) among terrestrial ecosystems. The effect of soil type on aboveground OC stocks and their annual increases (AI) of overstorey tree, understorey tree and ground vegetation layers in Estonian forest phytocoenoses with mature stands on mineral soils were studied. The study enfolds nine mineral soil groups, which are characterized by their phytocoenoses composition, soil cover properties and tree stands’ taxation data. An assemblage of soil and plant cover or plant–soil system is the main focus point in explaining causal and quantitative sides of ecosystems functioning. Surface densities of OC stocks in aboveground phytomass of forests varied significantly in the range of 52–100 Mg OC ha⁻¹. High AI or productivity (4.8–5.5 Mg OC ha⁻¹ year⁻¹) is a characteristic of forest ecosystems formed on leached, eluviated and pseudopodzolic soils. Forest ecosystem ground vegetation, which is an important ecological indicator, fulfils vacant ecological niches with herbs and/or mosses (up to 0.50 Mg OC ha⁻¹). The variation of ecosystem OC stocks and their AI by soil type should be taken into account in regional OC stocks and its annual increase estimations. Full article

Climate change-induced extreme changes are making phytomass yields of extensive grasslands in continental areas increasingly dependent on the season. This situation is exacerbated, inter alia, by the decline in grazing livestock production due to a lack of quality labour, and thus by an increase in the proportion of unused or under-utilised grassland. In our experiments, we have refined the effects of a decade of unused/abandonment, mulch, mowing and meadow utilisation on carbon emissions, soil moisture and soil temperature during two different types of years. We found that unused/abandonment grassland with accumulated duff in the absence of utilization had the highest carbon dioxide emission values in different years, even at lower soil moisture values. Our results confirm the fact that fallow grasslands can be considered a source of risk due to their increased greenhouse gas emissions. Full article

Imbalance of nutrients limits crop yields. Although K fertilization receives sufficient attention in research and practice, Mg supply is rather neglected. The effect of Mg fertilization (0, 5 and 10 g Mg/m²), combined with two K fertilization rates (10 and 15 g K/m²), on potato production and soil exchangeable K and Mg was studied in a three-season microplot field experiment in the Novosibirsk region, Russia. Tuber yield did not respond to the increased K fertilization, but increased at 5 and decreased at 10 g Mg/m². Total Mg concentration in tubers increased at 15 g K/m², whereas N, P and K were not affected by fertilization. The tuber yield was maximal (3.6 kg/m²) at 10 g K/m² and 5 g Mg/m². Soil exchangeable Mg increased by the year, resulting in preferential development of the aboveground phytomass due to apparently increased Mg availability and K/Mg imbalance. Potato production depended on the year, strongly implicating weather conditions. Therefore, the weather and the chemical nature of K and Mg fertilizers (as pertinent to their release mode from fertilizer in soil), are important for balancing their proportions and amounts while assessing interactions among nutrients in potato production and adjusting regional fertilization strategies. Full article

Salinity in soil can affect Jatropha seedling metabolism, interfering with plant establishment. In this study, the effect of salinity on the mobilization of reserves during the development of Jatropha seedlings was tested. Two genotypes of Jatropha were used and three concentrations of NaCl were applied between the 4th and 8th days after germination. The effects of salinity on seedling growth, in terms of fresh and dry phytomass, ionic partition, and sugar quantification, starch, proteins, amino acids, and lipids were evaluated in cotyledon leaves, hypocotyls, and roots. There was an increase in the content of all classes of macromolecules analyzed in at least one of the organs. It is hypothesized that the hypocotyls acted as an accumulating organ of Na⁺. The accumulations of amino acids and protein in roots suggest that metabolic responses occurred in response to the ionic and osmotic effects of NaCl, although this accumulation did not appear to prevent biomass losses in seedlings. Furthermore, the findings of this study demonstrate that salinity inhibits the mobilization of lipids and carbon stocks from cotyledon leaves to the rest of the plant, and together with the synthesis of proteins and amino acids that occurred primarily in roots, contributed to response of these plants to salinity. Full article