Search Results (13)

Heavy-textured soils in monsoon-affected regions face challenges related to waterlogging and structural degradation, yet the long-term efficacy of biochar as a physical soil amendment under such conditions remains inadequately understood. This two-year field study (2018–2019) therefore evaluated the transient impacts of birch-derived biochar (360–380 °C pyrolysis; 0, 1, 3 kg/m²), subsurface drainage systems, and fertilizer regimes on key physical properties of Endoargic Anthrosols (clay loam) in coastal Primorsky Krai, Russia. Granulometric composition remained stable (silt loam: sand 42–48%, silt 38–44%, clay 12–16%), though drainage significantly increased the silt fraction by >7.5% (p < 0.05). Biochar induced short-term reductions in bulk density (ρ_b; max −12% at 3 kg/m², 2018) and aggregate density (ρ_a; max −9.3%, 2018), but these effects dissipated by 2019 due to tillage redistribution and monsoonal fragmentation, as verified by SEM. Total porosity fluctuated seasonally (0.50–0.65 cm³/cm³), peaking post-tillage but declining under monsoon saturation, with no significant sustained biochar contribution. Crucially, intra-aggregate pore architecture (2–50 nm) resisted amendment-induced changes; N₂ adsorption showed treatment-invariant mesopore dominance (65–75% volume; mean pore diameter 17–21 nm), attributable to biochar’s physical exclusion (>1 µm particles from sub-0.5 µm pores) and inert fragmentation. Drainage dominated structural dynamics, modulating pore volume seasonally (−15% in 2018; +18% in 2019), while organic fertilizer enhanced porosity through polysaccharide-stabilized microaggregation (+22%, 2019). We conclude that biochar’s physical benefits in clay loams under monsoon climates are transient and dose-dependent, operating primarily through inter-aggregate macroporosity rather than intra-aggregate modification, necessitating reapplication for sustained improvements. Full article

This study systematically analyzes land use changes in the Russian Far East from 2000 to 2020, identifying key transformations and their driving factors. Using multi-temporal remote sensing images combined with land use dynamics analysis, transition matrices, and gray relational analysis, this research comprehensively evaluates land use evolution and its influencing factors. The purpose of this study is to elucidate how land use patterns shift under the influence of natural conditions, demographic trends, and cross-border cooperation with a particular emphasis on the border areas adjacent to northeast China. The findings reveal that during the observed period, the Far East underwent substantial expanses in arable land and built-up areas, while forest areas underwent a decline. Grassland areas demonstrated relative stability, water bodies continued to decrease, and unused land exhibited fluctuating trends, initially increasing and then decreasing. In the three border regions (Amur Oblast, the Jewish Autonomous Region, and Primorsky Krai), these transformations were more pronounced compared to the Far East overall, reflecting intensified agricultural development and urban growth in these strategic zones. Gray relational analysis shows that climate change and local population growth are the principal drivers of land use change, while regional trade—particularly China–Russia trade in industrial raw materials, agriculture, and food exports—plays a moderate role. The evolving land use patterns in the Far East carry significant implications for resource acquisition, ecological security, and regional cooperation. The study underscores the necessity of formulating scientifically sound land management policies to balance economic development with ecological protection, thus fostering sustainable development and regional stability. Full article

Based on our own field data and using modeling of modern potential ranges (in the MaxEnt program), an assessment of the spatial distribution of the rare representative of the longhorn beetle family, Callipogon (Eoxenus) relictus Semenov 1899, was conducted in northeast Asia (220 geographic locations). The generated maps of the potential range of C. relictus demonstrate a high likelihood of the species’ presence in the upland areas of southern far east Russia, the provinces of northeastern China, and the Korean Peninsula. Field data also indicate the extensive association of the species with undisturbed broadleaf and coniferous–broadleaf forests in northeast Asia. Maps of the potential distribution of C. relictus in northeast Asia have been compiled based on four climate change scenarios from the present time to 2070. Under all of the climate scenarios used, it is shown that suitable habitats for the species will persist in certain areas of Primorsky Krai, as well as neighboring provinces of the People’s Republic of China and a small enclave on the Korean Peninsula in Gangwon-do province. Significant reduction in suitable conditions for the rare longhorn beetle will occur in the rest of its distribution range. Full article

In this study, the biodiversity of endophytic bacteria of cultivated grape varieties from the vineyards of Primorsky Krai, Russia, was analyzed for the first time. Far Eastern grape varieties with a high level of stress resistance are a unique object of research as they are cultivated in cold and humid climates with a short summer season. Grapevine endophytic microorganisms are known as promising agents for the biological control of grapevine diseases and agricultural pests. Using genomic approaches, we analyzed the biodiversity of the endophytic bacteria and fungi in the most common grape varieties of Primorsky Krai, Russia: Vitis vinifera × Vitis amurensis cv. Adele (hybrid No. 82-41 F³), Vitis riparia × V. vinifera cv. Mukuzani (pedigree unknown), two cultivars Vitis labrusca × V. riparia cv. Alfa, and Vitis Elmer Swenson 2-7-13 cv. Prairie Star for the first time. The main representatives of the endophytic microorganisms included 16 classes of bacteria and 21 classes of fungi. The endophytic bacterial community was dominated by Gammaproteobacteria (31–59%), followed by Alphaproteobacteria (9–34%) and, to a lesser extent, by the classes Bacteroidia (9–22%) and Actinobacteria (6–19%). The dominant fungal class was Dothideomycetes (43–77%) in all samples analyzed, with the exception of the grapevine cv. Mukuzani from Makarevich, where Malasseziomycetes was the dominant fungal class. In the samples cv. Alfa and cv. Praire Star, the dominant classes were Tremellomycetes and Microbotriomycetes. A comparative analysis of the endophytic communities of the cultivated grape varieties and the wild grape V. amurensis Rupr. was also carried out. We found that 18–20% of the variance between the endophytic communities accounted for the differences between the cultivated and wild grapevines, while the factors “plant location” and “individual plants” accounted for 50–56% and 3–10% of the variance, respectively. The results of this study can be used to develop new means of biocontrol in vineyards to protect plants from abiotic stresses and pathogens. Full article

Blue honeysuckle (Lonicera caerulea L.) bears dietary fruits that are rich in bioactive compounds. However, information on the metabolome profiles of honeysuckle varieties grown in Russia is limited. In this study, we employed tandem mass spectrometry to study the metabolome profiles of four L. caerulea varieties (Volhova, Tomichka, Goluboe vereteno, and Amfora) grown in two geographical locations in Russia, i.e., the Russian Far East and St. Petersburg. We observed that the metabolome profiles of the four varieties grown in two locations differ significantly, particularly in the polyphenol’s other compound classes. We were able to identify 122 bioactive compounds in extracts from honeysuckle berries, 75 compounds from the polyphenol group and 47 compounds from other chemical groups. Thirty chemical constituents from the polyphenol group (flavones jaceosidin, cirsiliol, sophoraisoflavone A, chrysoeriol-O-hexoside, flavonols dimethylquercetin-3-O-dehexoside, rhamnocitrin, rhamnetin II, stilbenes pinosylvin, resveratrol, dihydroresveratrol, etc.) and twenty-seven from other chemical groups were identified. The largest number of unique polyphenols is characteristic of the variety Tomichka, the selection of the regional state unitary enterprise “Bakcharskoye”, from the free pollination of L. caerulea, originating in the Primorsky Territory of Russia (L. caerulea subspecies Turczaninow). This genotype has the highest number of similar unique polyphenols, regardless of where it was grown. Blue honeysuckle genotypes originating from Primorsky Krai in Russia can be used in various breeding programs in order to improve and enrich the biochemical composition of fruits. It should also be noted that, regardless of the place of cultivation, the total amount of unique polyphenols remains quite large. Attention should be paid to the Volhova honeysuckle variety, obtained through gamma irradiation of the Pavlovskaya variety (Kamchatka ecotype). This sample is characterized by a stable composition of biologically active substances, regardless of the growing area. These data could support future research on the production of a variety of pharmaceutical products containing ultrapure extracts of L. caerulea. Full article

Here, we report the first detection of the North American leaf-mining moth Chrysaster ostensackenella (Fitch, 1859) (Lepidoptera: Gracillariidae) on North American black locust Robinia pseudoacacia (Fabaceae) in Primorsky Krai (the Russian Far East) in July 2022. Overall, six moths were reared from the leaf mines and identified based on adult morphology (forewing pattern and male genitalia) and three of them were DNA barcoding. Description of the leaf mines that allowed us to distinguish the damage of Ch. ostensackenella from other gracillariids associated with R. pseudoacacia is provided. The phylogeographic analysis comparing the DNA barcodes from Russia with those from other invaded countries in Europe (Italy) and East Asia (South Korea and Japan) and from the native range (North America) was performed. Intraspecific genetic diversity reached 3.29%. Altogether, 10 haplotypes were revealed among 21 studied specimens in the Holarctic. The detection of one haplotype common for Japan and the USA (North Carolina) suggests that the invasion to East Asia could have happened from the USA directly, rather than through Europe. A shared haplotype defined for Japan and the Russian Far East points at a possible moth species’ spread to Primorsky Krai from earlier invaded Hokkaido. Further distribution of Ch. ostensackenella in East Asia and Europe is expected, bearing in mind the wide planting of R. pseudoacacia in these continents. Furthermore, an accidental introduction of the moth to the Southern Hemisphere, where black locust was introduced, is not ruled out. Full article

The potential of cross-border regional cooperation development is important for evaluating the present and future capacity for regional development. Primorsky Krai (Russia) and Jilin (China) share borders and complementary advantages. China and Russia have growing intention to strengthen cooperation, with geopolitical considerations. This study constructs a regional development potential assessment index system from the perspective of cross-border cooperation, and it establishes a multilayer cross-border regional development potential assessment (RDPA) model with three layers: target, factor, and indicator. By coupling four modules (economic, social, transportation, and resource environment), this study builds a development potential value system. The results illustrate that Primorsky Krai and Jilin have potential for cross-border cooperative development. The results reveal that Primorsky Krai has comparative advantages in port logistics, agriculture, fishery, and mining, which are all complementary to Jilin. These are important directions for cross-border international cooperation. Additionally, this study provides suggestions on decision-making and strategy consultation for the international cooperation between Jilin and Primorsky Krai and creates references for the study of cross-border cooperation opportunities and challenges for other neighboring regions around the world. Full article

The species diversity of lamellicorn beetles (Coleoptera, Scarabaeoidea) on the 20 islands of Peter the Great Gulf was considered and analyzed for the first time, where 83 species from 38 genera were identified. There are 60 species (72.3%) and 20 genera (52.6%) are new for the fauna of the islands, with reference to the literature data. The total fauna with Russky Island (21 islands) includes 87 species from 38 genera of 13 subfamilies and four families of the superfamily Scarabaeoidea. The diversity and degree of study of the group on individual islands is very uneven. Russky Island with 80 species (92% of the total fauna of 21 islands), Popov Island with 42 species (48.3%) and Putyatin Island with 39 species (44.8%) have the most species-rich fauna. On the islands of Kozlov, Rikord, Zheltukhin, and Durnovo, one species was recorded (1.1%). The Scarabaeidae Latreille, 1802 is dominates the fauna of 21 islands—77 species (88.5%), other families are represented by a single species: Trogidae Macleay, 1819—5 species (5.7%), Lucanidae Latreille, 1804—3 species (3.5%), Geotrupidae Latreille, 1802—2 species (2.3%). Scarabaeinae with 15 species (19.5%), Aphodiinae Leach, 1815 with 14 species (18.2%), and Rhizotroginae with 13 species (16.9%) are dominant in the Scarabaeidae fauna. The article deals with the annotated list of species and the studied material, discusses the ecological and zoogeographical features of the local faunas of Scarabaeoidea and features of the faunagenesis of the study area. The local Scarabaeoidea faunas of the islands are characterized by a significant depletion and mosaic composition of the species composition in comparison with the continental fauna. Despite the peculiarity of the climatic conditions of the islands and their significant isolation from the continental coast, the insular faunas of Scarabaeoidea demonstrate a high degree of similarity to the area, and have a logical structure with the continental fauna of lamellicorn beetles due to the geological youth of the island. The islands appeared during the post-Pleistocene transgression of the sea 11 to 8.5 thousand years ago. Full article

Mines, quarries, dumps, and tailings are the sources of air pollution. In the Dalnegorsk District (Primorsky Krai, Russia), there are 20 polymetallic deposits. This study aimed to evaluate the particle size and material composition of ambient particulate matter (PM) in Dalnegorsk town and verify the influence of mining and chemical industry facilities on the composition of PM. Ambient particulates were analyzed in samples of snow cover and washout from vegetation (conifer tree needles). According to particle size distribution data, the relative content of particles with a diameter up to 10 microns (PM₁₀) reaches 40% in three snow samples taken in the central part of the town. Among ore minerals, pyrite and arsenopyrite predominated in the samples. In addition, sphalerite, galena, cassiterite, and iron–chromium–nickel formations of various shapes were found in the studied particles. The presence of these metals in airborne PM can negatively affect the incidence rate of PM-associated diseases and the determination of their levels are very useful for air pollution prevention strategies. Full article

Understanding the effects of nitrogen (N) fertilizer on soybean-weed competition is essential for establishing a practical tool for N application and weed management. A two-year field experiment was conducted in a soybean field located in Bogatyrka (43.82° N, 131.6° E), Primorsky krai, Russia, to investigate the effects of N fertilizer and multiple-weed interference on soybean (Glycine max) yield and to model these effects. Soybean yield loss caused by the interference of multiple weeds including common ragweed (Ambrosia artemisiifolia), barnyard grass (Echinochloa crus-galli), and American slough grass (Beckmannia syzigachne) at different levels of N fertilizer was accurately described by a combined model incorporating inverse quadratic and exponential models into the rectangular hyperbolic model for two parameters Y₀ and β, respectively. The combined model used in our study indicated that the application of N up to 36 kg N ha⁻¹ can increase weed-free soybean yield by 2.2 Mg ha⁻¹ but soybean yield under multiple-weed interference can sharply decrease with increasing total density equivalent, particularly at 36 kg N ha⁻¹. These results, including the combined model, thus can support decision making for weed management under different N uses in soybean cultivation. Full article

This study was conducted to establish a weed management system based on the sequential application of pre-emergence (PRE) and post-emergence (POST) herbicides for soybean production in Primorsky krai. Field experiments were conducted for two years in a field located in Bogatyrka, Primorsky krai, Russia (N43°49′, E131°36′). No herbicide application resulted in significant soybean yield loss, 0.03–0.3 t ha⁻¹, which is more than 91.6% yield loss compared with that of the weed-free plot. The PRE application of acetochlor showed good weed control efficacy (greater than 90% weed control) with acceptable soybean safety (less than 10% soybean damage), while the other PRE herbicides performed poorly in terms of weed control. The POST application of bentazon + acifluorfen, bentazon, and imazamox at 30 days after soybean sowing (DAS) showed good weed control efficacy with good soybean safety. Neither the PRE nor POST application alone showed a sufficient soybean yield protection, resulting in much lower soybean yield than the weed-free plot. The sequential application of acetochlor (PRE), followed by either bentazon + acifluorfen (POST) at 30 DAS in 2012 or bentazon + imazamox (POST) at 60 DAS in 2013 showed the best performance in soybean yields, 1.7 t and 1.9 t ha⁻¹, respectively, provided with 724.5 US$ and 1155.6 US$ ha⁻¹ of economic returns. For alternative PRE herbicides of acetochlor, which is now banned, our tests of the sequential application of S-metolachlor with other POST herbicides and the sole application of other PRE herbicides revealed that S-metolachlor and clomazone could also be considered. Our results thus demonstrate that the sequential applications of PRE and POST herbicides should be incorporated into the weed management system for soybean production in Primorsky krai, Russia. Full article

Parameters and conditions of crystallization for the majority of hypergenic and technogenic minerals have not yet been studied, as their determination is often difficult due to their imperfect crystalline structure (X-ray amorphous) and formation in polymineral compounds. The article discusses the formation conditions of 20 hypergenic and technogenic minerals from technogenic waters in the mining industrial system of the Kavalerovsky district tin–sulfide deposits (Primorsky krai) in Russia. For various ratios of hypogenic minerals–host rocks in ore and in tailings in a wide temperature range (from −25 to 45 °C), the Eh-pH parameters and the minerals paragenesis were established. All hypergenic and technogenic minerals formed during modeling were found and diagnosed in the Kavalerovsky tin–ore district mining industrial technogenic system. Full article

The spatial distribution and dynamic changes of the forests in Primorsky Krai, Russia, are of great significance for regional ecological security and sustainable economic and societal development. With the support of the Google Earth Engine cloud computing platform, we first synthesized yearly Landsat surface reflectance images of the best quality of the research area and then used the random forest method to calculate the forest classification probability of the study area year by year from 1998 to 2015. Furthermore, we used a time–series segmentation algorithm to perform temporal trajectory segmentation for forest classification probability estimation, and determined the spatial and temporal distribution characteristics and change laws of the forest. We extended the existing algorithms and parameters of forest classification probability trajectory analysis, achieving a high overall accuracy (86.2%) in forest change detection in the study area. The extended method can accurately capture the time node information of the changes. In the present research we observed: (1) that from 1998 to 2015, the forest area of the whole district showed a net loss state, with a loss area of 0.56 × 10⁶ ha, of which the cumulative forest disturbance area reached 1.12 × 10⁶ ha, and the cumulative forest recovery area reached 0.55 × 10⁶ ha; and (2) that more than 90% of the forest change occurred in areas with a slope of less than 18°, at a distance of less than 20 km from settlements, and at a distance of less than 10 km from roads. The forest disturbance monitoring results are consistent with the changes in official statistical results over time, but there was a 20% overestimation. The technical method we extended in this study can be used as a reference for large–scale and high–precision dynamic monitoring of the forests in Russia’s Far East and other regions of the world; it also provides a basis for estimating illegal timber harvesting and determining the appropriate amount of forest harvested. Full article