Earticle

Tropical forests host around 10% of world’s forests and inhabit nearly half of the world’s tree species. Despite extensive research on the quantitative assessment of tropical flora, enumeration of long-term changes in species composition, population structure, and distribution patterns remain limited. We assessed the changes in structure, composition, and distribution patterns of tree species in preservation plots of Chhattisgarh for 30 years interval. A total of 102 tree species (including three lianas) were recorded across both sampling periods. The 2021 survey quantified 79 tree species belonging to 64 genera and 32 families, while the 1991 survey reported 87 species, 72 genera and 33 families. Only 68 species (66.7%) were common to both surveys, belonging to 55 genera and 30 families. In 1991, species richness ranged from 19 to 46 species while in 2021, it varied from 9 to 43 species. The structural changes at both community and species levels were significant (p＜0.05). The considerable changes were observed in proportionate frequency of tree, sapling, and seedling growth forms. These results exhibit significant change in vegetation structure and composition of forests during past 30 years.

The future of some tree species may be at risk due to genetic erosion owing to the fast decline in the world’s forest cover and overexploitation of goods. Therefore, understanding seed production, dispersal and the fate of seed populations, and seedling growth is crucial to revitalization of these species and channelizing the change towards ecosystem restoration. The study aims to estimate the seed production, dispersal, fate of seed populations, and seedling growth of Lagerstroemia speciosa in the Eastern Himalayan region of India. The results indicate that seed production significantly varied between the years (p＜0.05) and among individual trees (p＜0.01). The findings also showed strong positive correlations between seed production and tree characteristics such as DBH, number of branches, inflorescences, crown height, crown diameter. Additionally, there was a strong negative correlation between the number of seeds dispersed per unit area and dispersal distance from the mother tree (r=-0.88 in 2022 and r=-0.76 in 2023), with a significant difference observed in 2023 (p＜0.05). We found that 85% of the total seed produced fell directly under the mother tree, with fewer seeds dispersed farther away. However, seed disappearance decreased with increasing distance from the mother tree. Moreover, a correlation was observed between seedlings’ growth parameters and microclimatic variables. The restricted spatial extent of seed dispersal has important implications for the dynamics, management, and conservation of L. speciosa.

Salinity is one of the leading environmental hazards of Bangladesh and also for the coastal regions of the world. Therefore this study explores the spatiotemporal dynamics of land use land cover change (LULCC) analyzed by the Landsat 8 images of the year 2014 and 2024 and detects the effect of salinity on LULCC in three upazilas of Satkhira district of Bangladesh. 162 soil samples were collected from 0-20 cm depth from different land use classes using systematic random sampling technique to make composite samples. These collected soil samples were analyzed for different chemical properties and salt characteristics. The satellite imagery analysis revealed that water body and agricultural land have been declined at an alarming rate between 2014 and 2024 but shrimp cultivated area showed a substantial increase (40.01%) from the base year. From the soil sample analysis, it was found that most of the land in the study area had low organic matter with pH less than 8. The higher concentration (24.6 dS/m) of soil electrical conductivity (EC) and cation exchange capacity was also observed in these areas. Due to high soil EC value, the area under agriculture has decreased significantly and most of these areas have been converted to shrimp cultivation because of salinity. Nonetheless, this study does not assess the impacts of land use land cover change for salinity intrusion on local communities. Still, these findings will benefit the policymakers and stakeholders in taking suitable actions to reduce the impacts of soil salinity on land use change in the coastal areas at local, regional and global scales.

This study assessed the impact of wildfires on forest ecosystems by examining beetles, which are environmental indicator species. Beetles were surveyed in the wildfire-affected areas of Miryang-si, South Korea, from July 2022 to October 2024 using pitfall traps, net sweeping, and direct collection methods. In 2022, 483 beetles from 15 species across eight families, yielding diversity, evenness, and dominance indices of 1.096, 0.931, and 0.091, respectively. By 2023, 1,176 individuals were recorded from 35 species across 15 families, yielding diversity, evenness, and dominance indices of 1.406, 0.911, and 0.046, respectively. In 2024, 1,038 individuals will be recorded from 33 species across 14 families, yielding diversity, evenness, and dominance indices of 1.400, 0.922, and 0.039, respectively. The similarity index between 2022 and 2023 is 52%, that between 2022 and 2024 is 50%, and that between 2023 and 2024 is 88%. The two-banded ground beetle (Macrochlaenites naeviger) had the largest number of individuals (219), followed by the flower chafer beetle (Gametis jucunda) (184), the variegated cutworm weevil (Sitona aberrans) (175), the bean leaf beetle (Popillia mutans) (172), the small ground beetle (Hemicarabus tuberculosus) (141), and the pine sawyer beetle (Rhagium inquisitor) (137). Correlation analysis of the common species at each survey site revealed a strong positive correlation (r=1.000) between hongdan (Coptolabrus smaragdinus) and the two-banded ground beetle species. A strong negative correlation (r=-1.000) was observed between the Chinese ground beetle (Nebria chinensis) and the three-spotted leaf beetle (Paridea angulicollis). A strong positive correlation (r=1.000) was also observed between the pairs of pine sawyers and broad-bodied carrion beetles (Eusilpha jakowlewi) and the seven-spotted ladybug (Coccinella septempunctata) and black pine weevil (Niphades verrucosus).

Molecular phylogenetics and population genetics are key to understanding the evolutionary dynamics and conservation of endangered species. The long-tailed goral (Naemorhedus caudatus) listed as Endangered class I and Natural monument in South Korea, is experiencing population decline due to habitat destruction and fragmentation, necessitating conservation efforts. So, this study used mtDNA control region sequences to investigate intraspecific phylogenetic relationships and haplotype networks of long-tailed gorals in South Korea. Intraspecific phylogeny showed two major clades, A and B, indicating complex genetic structure and historical and contemporary gene flow between populations in Gangwon-do and Gyeongbuk regions. Haplotype diversity (Hd) of long-tailed gorals was relatively high (0.839) but nucleotide diversity (π) was low (0.00661) indicating recent divergence. The findings of this study provide critical insights into the genetic structure and evolutionary history of long-tailed gorals, laying the foundation for informed conservation measures. By identifying genetic connectivity and regional divergence among populations, this study emphasizes the importance of targeted actions to maintain genetic diversity, improve ecological connectivity, and mitigate the effects of habitat fragmentation for long-term survival of this endangered species in South Korea.

This study investigated the chemotaxonomic classification of Alnus species using oregonin, a diarylheptanoid compound, as an indicator. Alnus species are widely distributed across Asia, Africa, Europe, and North America, and have been recognized for various biological activities, such as antioxidant, anti-inflammatory, anticancer, and muscle-protective effects. As a result, chemotaxonomic studies using oregonin as an indicator compound are crucial for utilization of Alnus species resources. However, research comparing Alnus species based on growth region and country remains limited. In this study, 17 Alnus samples from South America, North Africa, and Asia were analyzed using oregonin as a marker compound. Oregonin was directly isolated from Alnus japonica, a species native to Korea, and used as a standard compound for chemotaxonomic analysis. HPLC and LC-MS/MS analysis were conducted to compare the samples. HPLC analysis identified peaks with retention times similar to oregonin in 11 samples, including those from Ecuador, Peru, Tunisia, Nepal, China, and Korea. LC-MS/MS analysis confirmed the presence of oregonin in all these samples, with molecular weights of 476.9-477.2 m/z. HPLC and LC-MS/MS analysis revealed that more than half of the examined samples contained oregonin, suggesting that oregonin could serve as a reliable chemotaxonomic marker for Alnus species. The study also found that the oregonin content varied significantly based on the extraction site, growth region, and country of origin. Notably, Alnus japonica samples from the Baekdudaegan Mountain Range in Korea (Chuncheon, Yangyang, and Jeongseon) exhibited higher oregonin content than those from other countries, suggesting that regional environmental conditions influence oregonin production. These findings highlight the potential of Korean Alnus species as a valuable natural resource. This research confirms that oregonin is a reliable chemotaxonomic marker for identifying Alnus species across various regions and provides essential data for the development and utilization of high-value natural products derived from Alnus species.