Interspecific interactions and correlations provide vital insights into species relationships and the overall stability of plant communities, which are essential for understanding the dynamics of vegetation restoration and biodiversity conservation. This study examined the interspecific associations and correlations within the evergreen broadleaved forest of Bidoup-Nui Ba National Park in southern Vietnam. The investigation was based on a comprehensive survey of all trees with a diameter at breast height (DBH) greater than 2.5 cm within a 4-ha study plot. A variety of analytical methods, including variance ratio (VR), chi-square test, association coefficient (AC), Ochiai Index, Pearson and Spearman correlation coefficients, and principal component analysis (PCA), were employed to assess the relationships among twelve dominant tree species. The results revealed the following key findings: (1) the community exhibited predominantly positive associations, suggesting a stable successional phase; (2) the ratio of positive to negative correlations exceeded 1, with a significantly higher number of positive correlations, reflecting stronger interspecific associations; (3) Spearman’s rank correlation test demonstrated greater sensitivity compared to other correlation methods; and (4) the classification of ecological species groups aligned with the correlation results, emphasizing the substantial influence of ecological traits and resource utilization strategies on interspecific relationships. These findings highlight the critical role of interspecific interactions in maintaining community stability and provide valuable insights for advancing ecosystem restoration and biodiversity conservation strategies.

Plantation forests consist primarily of planted or deliberately seeded trees and are intensively managed. It is expected that forests will play a more significant role in climate regulation in the future, as they are considered effective tools for combating climate change and absorbing carbon (C). To calculate the CO₂ uptake efficiency of planted forests at the Vietnam National University of Forestry (VNUF), this study estimated carbon capture and stock distribution in some planted forests in Luot Mountain. Random sampling was used to select a total of 20 rectangular plots of 500 square meters, with a dimension of 25 by 20 meters. Diameter at breast height (DBH) was measured by a diameter tape and caliper for trees with a diameter wider than 6 cm. The Blume-Leiss method was used to measure tree height. Overall biomass and carbon stocks aboveground in the study area were 62.4 tons/hectare and 31.2 tons/hectare, respectively. A carbon credit value of 91.55 USD/ha was assigned to the CO₂ and O₂ production and absorption potentials of 2288.94 (tons/ha) and 1670.92 (tons/ha), respectively. Forest conservation and management strategies should emphasize plantation preservation based on this study's findings because plantations store significant amounts of carbon.

Common bean (Phaseolus vulgaris L.) is an important legume crop with high nutritional value and is widely cultivated across diverse ecological zones. This study aimed to evaluate the genetic diversity based on morphological markers of 16 common bean accessions collected from the Priobia steppe, Siberia. The field experiment was conducted using a randomized complete block design (RCBD) with three replications during the 2023 and 2024 growing seasons at the National Agrarian University of Novosibirsk. Analysis of variance revealed significant differences (p < 0.05) among genotypes for most studied traits. A dendrogram based on genetic similarity coefficients ranging from 0.22 to 0.78 classified the genotypes into four distinct genetic groups, indicating high genetic diversity among the collected common bean accessions. Correlation analyses showed positive associations between seed yield and days to flowering (r g = 0.34 and r p = 0.34), number of pods per plant (r g = 0.64 and r p = 0.75) as well as hundred seed weight (r g = 0.62 and r p = 0.7), suggesting that selecting genotypes with higher mean values for these traits could enhance common bean yield. The findings provide a scientific basis for breeding programs and contribute to the conservation and effective utilization of common bean genetic resources within the Siberian agroecosystem.

Background: Common bean (Phaseolus vulgaris L.) is an important leguminous vegetable crop but the lack of high yielding and stable varieties is the major constraint. Exploring genetic variability is essential for crop improvement programs. Considering this, the present study focused on assessing genetic variability and associations between yield and its contributing traits to enhance production efficiency. Methods: A two year experiment was carried out at the experimental farm of the Novosibirsk State Agrarian University during the cropping season of 2023 and 2024 to find out the genetic variability parameters, path coefficient and correlation studies in twenty six common bean genotypes. Result: The results revealed high variability among the tested genotypes. The values of phenotypic coefficient of variation (PCV) were greater as compared to the genotypic coefficient of variation (GCV) for all the traits. High heritability along with GAM% ( greater than 20%) was observed for number of nodes per stem (NNS), number of pods per plant (NPP), number of seeds per pod (NSP), seed yield per plant (SYP), hundred seed weight (HSW) and pod width (PL). Seed yield per plant (SYP) had positive genotypic and phenotypic correlation with DF (rg = 0.34 and rp = 0.34), NPP (rg = 0.64 and rp = 0.75), HSW (rg = 0.62 and rp = 0.7) and PL (rg = 0.35 and rp = 0.4). Positive direct effect on seed yield per plant (SYP) was exhibited by traits viz., number of pods per plant (NPP), hundred seed weight (HSW) and days to 50% flowering (DF) in path coefficient analysis.

Interspecific relationships among plants represent fundamental structural and quantitative attributes that critically influence the formation, organization, and evolutionary dynamics of plant communities. The analysis of these relationships provides essential theoretical foundations and methodological tools for deciphering the mechanisms of community stability and succession, as well as for informing ecological restoration and reconstruction practices. However, the specific mechanisms through which community stability emerges in tropical forest ecosystems remain inadequately elucidated. This study investigated patterns of interspecific association and correlation, as well as community stability, in evergreen and semi-deciduous forests within the Nui Cau-Dau Tieng Protection Forest in southern Vietnam. Using data from 27 systematically surveyed sample plots, each covering 0.1 ha and containing a total of 2475 individual trees, an integrated analytical approach was applied. This approach incorporated the variance ratio method, chi-square tests, Pearson and Spearman correlation analyses, and Godron’s method. The findings revealed a significantly higher proportion of positive interspecific associations in the evergreen forest (68.33

Gaps have a significant influence on forest structure and development. This study analysed characteristics of gaps between secondary and old–growth forests in Kon Ka Kinh National Park, Gia Lai Province, Vietnam. One hectare inventory plots were established in each forest stage. Data on gap size, coordinates, average height of surrounding trees, slope and directions of main axes were recorded. Results showed that the secondary forest had slightly higher number of gaps, compared to old–growth forest. However, the average size of gaps was smaller. Frequency distributions were significantly different between the two forest stages. The size of the gaps correlated with the height of the surrounding forest canopy but there was no correlation with slope. The length direction of gaps was most concentrated at East–North–East in both forest types. The distribution of gaps were regular at a scale of 0 to about 15 m, but were random at larger distances. The gap size spatial distribution was random in the secondary forest, but 60

Forest structure is a key to effective forest management. This study analyzed diameter and height data collected from two plots in Tuyen Quang, Vietnam to elucidate the structural characteristics and carbon stocks of the forests. The forest volume varied between 77.59 and 103.93 m3, while the carbon stock ranged from 32.53 to 43.83 (Ton/ha). Additionally, the number of carbon credits spanned from 119.38 to 160.86. The best function for simulating the diameter frequency distribution was Wakeby and Gen. Gamma (4P). Meanwhile, the best function for the height frequency distribution was Dagum and Log-Logistic (3P). The regression between diameter and height was best described by the Power and Naslund equation. A strong association between diameter, height and forest tree quality was revealed in both plots. Good trees were typically clustered within groups with larger diameters and heights, whereas bad trees were predominantly found in the smallest groups. These findings will support the assessment of a forest's ecological functions, contributing to effective carbon sequestration initiatives and climate change mitigation efforts in the future.

Regeneration will determine the success of forest restoration and affect the sustainability of future forest ecosystems. Research has been conducted to evaluate the characteristics of the regeneration storey and their spatial distribution on the ground. The study has established 10 plots (100 m x 100 m) for secondary forests, 10 plots for old-growth forests. Sub-plots (2 m x 2 m) were set up systemically to investigate the regeneration. The results showed that 148 species in secondary forest and 130 species in old-growth forest were found. The number of families in the secondary forest was lower than in the old-growth forest by 3 families. The Simpson index of both forest states was high (0.9769 and 0.9799 respectively). Canonical correspondence analysis exposed that species composition of both species and families between the two types of stages was significant dissimilar. There were clear groups of species and families appeared together with similar frequency in plots proved by hierarchical classification. In both stages, the height frequency distribution was inverse-J shape forms. And these distributions were different in studied types. The good regeneration in two studies states of forests were 67.9% and 55.7%. Regeneration quality was significant associated with height and light classes. The number of regenerating trees generated in each 1-hectare plot of the secondary forest was almost twice that of the old-growth forest. In the secondary forest, most plots illustrated that the spatial pattern was random at all scales. Contrary, in the old-growth forest, the patterns were much more complicated.

The complete plastome size of Citrus hystrix DC. 1813 was 159,893 bp in length and has a typical quadripartite structure. The 87,148-bp-long large single-copy and the 18,763-bp-long small single-copy regions were separated by a pair of inverted repeats (each 26,991 bp). The plastome was predicted to contain 132 genes, of which 87 were CDS, 37 were tRNA, and eight were rRNA genes. The plastome was A/T biassed, and the overall GC content was 38.4%. Using maximum likelihood and Bayesian inference methods, the phylogenetic analysis of the complete plastome sequence revealed a close relationship between C. hystrix and C. aurantiifolia, placing them under the same clade as C. micrantha.

Các mô hình sinh khối cây cá lẻ đóng vai trò quan trọng trong việc ước tính sinh khối rừng. Nghiên cứu này phát triển các mô hình sinh khối dựa trên dữ liệu thu thập từ 90 cây keo lai tuổi từ 2-10 năm trong các lâm phần rừng trồng thuần loài tại Khu Dự trữ Sinh quyển Đồng Nai. Phương pháp cắt hạ và sấy khô được sử dụng để xác định sinh khối trên mặt đất (AGB) của cây. Trong đó, 60 cây được chọn ngẫu nhiên để xây dựng mô hình và 30 cây còn lại được dùng để kiểm định. Ba phương pháp mô hình hóa được áp dụng bao gồm hồi quy Ridge (RR), tương quan sinh trưởng (AG) và cây rừng (RF), với các biến đầu vào là tuổi (A), chiều cao vút ngọn (H) và đường kính ngang ngực (dbh), trong khi AGB đóng vai trò là biến phụ thuộc. Hiệu suất mô hình được đánh giá thông qua các chỉ số hệ số xác định (R²), sai số trung phương (RMSE) và sai số tuyệt đối trung bình (MAE). Kết quả cho thấy mô hình RF vượt trội hơn so với RR và AG, với R² cao hơn và các giá trị RMSE và MAE thấp hơn. Phân tích tầm quan trọng của các biến trong mô hình RF cho thấy dbh là yếu tố có ảnh hưởng lớn nhất đến kết quả dự đoán AGB. Thêm vào đó, việc tích hợp A vào RF đã cải thiện độ chính xác trong ước lượng AGB của cây keo lai. Kết quả nghiên cứu cung cấp cơ sở khoa học quan trọng cho việc ước tính nhanh và chính xác AGB của rừng trồng keo lai tại khu vực nghiên cứu.

Successful deoxyribonucleic acid (DNA) extraction from the durian fruit allows effective molecular identification and genotyping of durian cultivars for quality assurance. While most genetic identification of durian samples used the leaf as the DNA source, studies exploring durian fruit as a source of DNA for molecular identification and genotyping are limited. In this study, four potential sources of genetic material: the peduncle, spine, carpel, and aril from the durian fruit were evaluated for DNA yield (in terms of concentration), quality (in terms of ratio of A260/A280), and suitability in PCR amplification (using genetic markers that target the chloroplast, nuclear, and microsatellite DNA regions). Results of this study show that the spine is a good potential source of genetic material alongside the peduncle.

Nitrogen stable isotopes (δ15N) abundance provides useful information on nitrogen input, transformation, and output, which indirectly reflect the characteristics of nitrogen cycling in terrestrial ecosystems. Here, our primary objectives were to: (i) examine how seasonal changes affect the δ15N values in various soil depths, as well as in tree leaves and (ii) compare differences among three forest sites (Shushan National Forest Park_DSS), Zipengshan National Forest Park_ZPS, and Wanfoshan National Forest Park_WFS) representing urban, suburban, and rural environmental conditions in Anhui Province, China. Soil and plant foliar samples were collected seasonally from Quercus acutissima Carruth. forests among the three sites from July 2017 to June 2018. The study results revealed that: (1) There was a significant difference in the δ15N values between the 0-10 cm and 10-20 cm soil depths in all three experimental sites. (2) The seasonal change trends of δ15N in DSS at 0–10 cm soil depth demonstrated that values were highest in fall 2017 and lowest in summer 2017, whereas values at ZPS and WFS sites were highest in summer 2017 and lowest in spring 2018. At 10-20 cm soil depth, DSS and ZPS had maximum δ15N values in Fall 2017 and lowest in summer 2018. (3) The δ15N values in both young and mature leaves were notably greater at the urban sites than those at the suburban and rural sites. The findings from this study revealed that seasonal and site variation significantly increased the Nitrogen stable isotope composition.

In order to cope with forest degradation and deforestation, farm forestry is a new tool for plantation purposes that combat these issues. Planting trees on farmlands is the most practical and viable approach given in the current situation in Pakistan for recovering the degraded forest lands, ensuring the sustainable use of marginal areas, and satisfying the rural requirements for the benefits of trees, both economically and non-economically. Therefore a socio-economic study of farmers in relation to tree planting is very important, to understand farmers perception about farm trees growing. In this study a total of 120 households were surveyed and interviewed in district Malakand for factor affecting farm tree planting decision. The result of step wise binary logistics regression analysis indicated that the factors including: Education level, Attitude of tree planting and silviculture knowledge were significantly influenced on tree planting decision of household in the study area. The total household income for planter was significantly higher than non-planter. The study result may provide the basis for proposing solution for future to strengthen trees planting decision for plantation, with the intention of promoting household engagement and attract farmers towards plantation activities in the study area.

Indigenous knowledge, attitudes, and perceptions of local people are very important concepts for wildlife conservation. Endangered wildlife species that live in Kon Plong forests have been under pressure from the communities living around them, including wildlife hunting, trapping, capturing, illegal logging, and encroachment for residential and production land. This study aims to understand the knowledge, attitude, and behaviour of indigenous people towards endangered wildlife in order to protect these species. Some participatory rural appraisal tools were used to discuss the situation and collect information in nine villages of four communes in Kon Plong District from December 2019 to March 2020. The results showed that the levels of knowledge about endangered wildlife among indigenous people in communes were statistically different. People’s knowledge of the law influenced their behaviour. Gender had the greatest influence on the level of knowledge. Most indigenous people had a positive attitude and wanted to protect endangered animals. “Commune” and “culture” were the two factors affecting people’s attitudes. “Commune”, “culture”, and the level of understanding affected the hunting behaviour of people. Negative human impacts have seriously influenced endangered wildlife species. Therefore, it is necessary to develop a long-term conservation strategy and plan, including the establishment of Kon Plong Special-Use Forests, supporting livelihoods for local people, communicating, and raising awareness among local people, and increasing the participation of community organisations.

Forest management relies on forest spatial structure, but studies on the spatial structure of Vietnamese forests are limited. Therefore, two one–hectare plots were established in tropical rainforest in Tuyen Quang province to evaluate the characteristics and spatial structures of plant communities. Descriptive statistics and species importance value indices were calculated for each plot. Then, to assess differences between plots, detrended correspondence analysis was applied. Species mingling, uniform angle, diameter dominance and carbon stock dominance indices were also computed to analyze forest spatial structures. The results indicated that 65–70

Forests provide valuable resources while also significantly reducing the amount of carbon dioxide in the air. In addition to acting as carbon sinks, forests release carbon when there is land use for other purposes. This release of stored carbon occurs when biomass is removed from the forest. This study estimated the biomass and carbon stocks in pure Pinus wallichiana forest in the valley of Kumrat Dir Kohistan, Pakistan. The study area was divided into three different homogeneous strata. In each stratum 10 square shaped sample plots with plot size 0.1 hectare with fixed dimensions of (33 × 33 m) with a total of 30 sample plots were taken by following stratified random sampling method. To check the relationship of biomass and carbon stock with different parameter, regression models were developed. The results showed that in pure Pinus wallichiana forest, the biomass of upperstory vegetation have stored 465, 1.1 tC/ha in understory vegetation, deadwood, litter, cone have 10.92 tC/ha and soil have stored 63.23 tC/ha, with overall 540.25 t/ha of carbon. Ecological services in the region are provided by these natural coniferous forests, while maintaining carbon dioxide levels in the form of biomass. Results from this study will enhance to evaluate the role of these forests in regional and global C cycles, Reducing Emissions from Deforestation and forest Degradation (REDD+), sustainable forest management and policy matters on climate change.

Soil mineralization is a crucial soil process that improves soil physical properties, enhances carbon sequestration, and provides essential minerals and available nutrients for plant growth. This study was conducted at five vegetation types and soil depths at Luot mountain area, located in VNUF campus, Hanoi city. Samples were incubated in the dark at 25°C and measured at intervals of 1, 2, 5, 10, 15, 25, 35, and 40 days in the laboratory to determine C-CO2 respiration from soils. The study showed that CO2 emissions were highest in topsoils and decreased with deeper soil depths. Mineralized C-CO2 decreased from Shrubs > Acacia + Native species (NS) > Pinus + NS > Native species > Control. CO2 emissions peaked early in the incubation period and then stabilized in the 40-day incubation period. Larger aggregates (≥ 5mm) decreased significantly under most vegetation types, except for Shrubs, where the reduction was minimal. Aggregate size ≥3mm increased post-incubation, notably under Pinus + NS and Native species, with smaller aggregates also increasing slightly. Organic matter content was highest in the topsoil but decreased post-incubation due to microbial C mineralization. There was an increase in soil organic matter at 10-20 cm and 20-40 cm layers after incubation, especially under Shrubs. Available nitrogen slightly increased in soils post-incubation for most vegetation types. Phosphorus content increased post-incubation, peaking under Shrubs, while potassium levels were generally poor but increased during incubation. The study found that C-CO2 mineralization was strongly associated with soil porosity and pH, suggesting that higher porosity and optimal pH enhance mineralization, with organic matter content being crucial for available nutrient cycles in soils.

Forest structure is a key component of its management and assessment in every forest ecosystem. In the study, 23 plots were established to obtain data on the acacia forest community based on tree size. Results from the study indicated that the acacia community could be broadly divided into two groups based on tree-size variables. The diameter and height frequency distributions of Group 1 were right-skewed, while those of Group 2 were more complicated. In both groups, there were positive correlations between tree-size variables, nonetheless the relationship between diameter at breast height and total height was best described using the cubic equation. Further, the Weibull and Sinh-Arcsinh (SHASH) best simulated the diameter and height frequency distribution. High-quality trees were found in a large diameter (> 30 cm) and height groups (> 22 m). In contrast, low-quality plants often concentrated on the smallest sizes. Therefore, trees with a diameter of 2-10 cm and a height lower than 8 m should receive attention to tend. Carbon stock in the two groups was 61.48 Mg.ha(-1) and 64.21 Mg.ha(-1), respectively. Tending solutions and measurements should be carried out regularly to promptly propose silvicultural measures and improve forest quality in future.

Allometric models play an undeniable role for estimating hard-to-measure quantities such as volume, biomass and carbon stock in forests. However, so far there has been limited model development for native forests in Vietnam. Therefore, this study was conducted to build and analyze the effectiveness of nonlinear and mixed models for secondary and old-growth forests in Gia Lai, Vietnam. The study measured diameter at breast height, total height, commercial height and crown width of forest trees in 20 plots (10 plots for each forest stage). The results showed that diameter had the strongest relationship with height. In the secondary forest, the Power, Korf and Ratskowky models were the best for pairs of variables, while Prodan, Weibull and Power models were the best fit in the old-growth forest. The nonlinear mixed-effect models were better than classic nonlinear models in both forest stages. Fixed and mixed models developed in this study are very valuable for estimating difficult-to-measure quantities and contribute to effective forest management in the study region.