Search Results (2,896)

The expansion of Moso bamboo (Phyllostachys edulis) significantly alters the spatial configuration of surrounding trees, leading to dynamic shifts in the spatial distribution of coarse woody debris (CWD). Investigating the spatial patterns of CWD during bamboo expansion can reveal the dynamic mechanisms of forest communities in this process, thereby providing scientific insights for forest management and conservation. In this study, conducted within the Yangjifeng Biodiversity Monitoring Large Plot, all trees with a diameter at breast height (DBH) ≥ 1 cm within the plots were tagged and important variables were measured, including DBH, tree height, and spatial attributes. Coarse woody debris (CWD) with a DBH ≥ 10 cm was also measured, including DBH, diameters at both ends, length, and spatial attributes. Based on the importance values of tree species in each 20 m × 20 m plot—where an importance value comprehensively measured a species’ relative abundance, frequency, and dominance in the community—the sample plots were divided into three continuous sample transects: evergreen broad-leaved forest (EBF), bamboo–broadleaf mixed forest (BMF), and Phyllostachys edulis forest (PEF). Ripley’s ‘g’-function was employed to analyze the spatial patterns and associations of CWD across these three forest types. A random sampling approach was used to collect CWD samples for the measurement and calculation of carbon storage. Three key findings emerged. (1) With the expansion of Moso bamboo, the biomass and carbon storage of standing dead trees both decrease. The biomass is highest in EBF, followed by BMF and PEF. However, carbon storage is greatest in BMF and lowest in PEF. (2) With the expansion of Moso bamboo, the distribution of CWD became increasingly uniform in PEF; analysis of the overall spatial pattern of CWD indicated that with increasing spatial scale, CWD changed from an aggregated to a random distribution across all three forest types, with a pattern scale of approximately 10 m. In EBF, the CWD of Moso bamboo exhibited a random distribution at all spatial scales. Additionally, CWD across different diameter classes, decay stages, and types changed from aggregated to random distributions as the spatial scale increased, with a reduction in aggregation intensity correlated with larger diameter classes. (3) Finally, we found an almost exclusively negative spatial association between living trees and CWD across all scales, and this negative correlation may be attributed to the absence of new tree growth following tree mortality. Collectively, our findings demonstrate that during Moso bamboo expansion, the spatial distribution of CWD changes from aggregated to random, while maintaining a significantly negative spatial association with living trees. This reveals the dynamic changes in the spatial patterns of CWD during community development, thereby providing a scientific basis for the forest management of subtropical evergreen broadleaf forests and bamboo management and control. Full article

Computer-aided drug discovery increasingly depends on virtual-screening workflows that remain reliable under severe class imbalance, chemical redundancy and early-recognition constraints. In this study, we developed a leakage-aware prioritization workflow for two cancer-relevant targets, pyruvate kinase M2 (PKM2) and mitogen-activated protein kinase 1 (MAPK1/ERK2), using the LIT-PCBA benchmark. The workflow combines canonical-SMILES curation, duplicate and label-conflict auditing, scaffold-aware validation, a non-learning nearest-active Tanimoto baseline, imbalance-aware machine-learning models, repeated-seed robustness analysis, isotonic probability calibration, ensemble-disagreement estimation, absorption, distribution, metabolism, excretion and toxicity (ADMET)-aware triage, molecular docking, and residue-level contact analysis. Benchmark enrichment is interpreted alongside calibration, ADMET filtering, docking and residue-contact evidence, rather than as a standalone discovery claim. PKM2 emerged as the clearer machine-learning case, with scaffold-aware tree models improving early recognition beyond the nearest-active similarity baseline and yielding top-ranked candidates supported by calibrated activity scores, ADMET profiles, docking scores, and residue-contact fingerprints. MAPK1 provided a biologically relevant contrast target, where ligand-neighborhood similarity remained competitive and downstream structural triage became more decisive than ligand-based ranking alone. These results support a conservative drug-discovery workflow in which leakage-aware benchmarking, calibration, uncertainty, and molecular-level triage remain visible throughout candidate prioritization. Full article

The roles of proline in stress tolerance, energy metabolism, immune function, and ecology across organisms suggest a broader relevance in orchard agroecosystems than is often recognized. In fruit trees, stress-induced proline accumulation reflects a complex regulatory network, while evidence also indicates that inter-organ transport contributes to protective responses under abiotic stress. In insects, proline functions as an oxidative substrate priming the rest-to-flight metabolic transition in pollinators and pests, a cryoprotective osmolyte and a structural element of conserved classes of antimicrobial peptides against microbial threats. These roles create paradoxical orchard-scale feedbacks while a stress-protective molecule both intensifies herbivore pressure and enhances pollination and biocontrol services. The orchard environment represents a meeting point of plant, environmental, animal and human health, reflecting the integrative logic of the One Health framework, where proline emerges as a highly water-soluble and bioactive compound. The functional homology between insect and human proline catabolism emerges governance-critical issues across tree physiology, insect immunity and human dietary exposure. The targeted application offers a unifying framework for farmers, scientists and policymakers to advance Sustainable Development Goal commitments across food security, human health, climate resilience and biodiversity. We conclude that proline supplementation in orchards requires regulatory monitoring across ecophysiological and pharmaceutical dimensions. Full article

Ecological interactions are complex and influenced by historical, ecological, and anthropogenic factors. In mutualistic networks, extrafloral nectaries (EFNs) drive ant–plant interactions, and network structure depends on the ecological flexibility and degree of generalization of the species involved. We evaluated whether plant and ant diversity and topological descriptors, at both network and plant-species levels, differ between networks with and without EFNs and between conservation levels of Neotropical savannas, considering total ants (arboreal and non-arboreal) and only arboreal ants. We sampled six remnants of Neotropical savannas (cerrado sensu stricto) in the Brazilian Cerrado, three preserved and three disturbed. In total, we analyzed 24 interaction networks, involving 45 plant species, 51 ant species, and 358 distinct interactions. Plants without EFNs were richer and more abundant, and nestedness was the only descriptor that varied, being higher in preserved areas (for total ants) and in networks with EFNs (for arboreal ants). In addition, EFN-bearing species showed higher degree, betweenness centrality and closeness centrality. EFN-mediated interactions play a stabilizing role in ant–plant networks, particularly in preserved areas, and maintaining EFN-bearing plant species may promote interaction redundancy and functional resilience in human-impacted savannas. Full article

Thioredoxin (TRX) is an important redox-related protein, which plays a key role in maintaining redox balance in cells. However, the role of TRX in ammonia exposure of Oreochromis niloticus is still unknown. In this study, we successfully cloned the TRX gene (OnTRX) of O. niloticus and performed systematic bioinformatics analysis. The results of multi-sequence alignment and phylogenetic tree analysis showed that OnTRX is highly conserved in vertebrates, but exhibits low sequence similarity with TRX homologs from arthropods (crustaceans). The tissue distribution of OnTRX and its transcriptional response to ammonia challenge were determined by qRT-PCR, and we further investigated the relationship between OnTRX and the response of the Nile tilapia epithelial cell line (TSE-04) to NH₄Cl treatment. The results showed that OnTRX exhibited tissue-specific expression, with a relatively high expression level in gill tissue. Ammonia exposure could significantly induce the expression of OnTRX in the gill, head kidney, intestine, skin, liver, and spleen of tilapia. In TSE-04 cells, OnTRX overexpression was associated with reduced NH₄Cl-induced morphological damage, a lower proportion of apoptotic cells, and altered transcript levels of several stress-related genes. Collectively, these findings indicate that OnTRX is likely involved in the regulatory response of Nile tilapia to ammonia-induced stress, while the underlying molecular mechanisms thereof remain to be further elucidated. Full article

Evolutionary trees are of central importance in biology to develop explanatory frameworks for many kinds of studies, including studies of behaviour, ecology, and conservation. Since the last major estimate of evolutionary relationships among many bumblebee species two decades ago, there have been revisions to their taxonomy, descriptions of new species, and sequencing of many rarer species. By combining: (1) earlier data mostly from slow-evolving nuclear genes as a backbone tree; with (2) new data from fast-evolving mitochondrial COI barcodes to resolve more of the twigs on the tree, including sequences obtained from rare old specimens with ancient DNA techniques; as well as (3) the results from broader genomic data for resolving deep relationships, we make a Bayesian estimate of evolutionary relationships with BEAST 2 among all 289 published and accepted extant bumblebee species, an increase of more than 29% of the species on the previous largest tree. The new tree will serve as a framework for future comparative studies that should enable broader insights into the evolution and ecology of all bumblebees. We illustrate this with an analysis of the evolution of some male morphological characters related to male mate-searching behaviour. We also present a novel map of spatial variation in net diversification rates among bumblebee species world-wide, which indicates an especially rapid net diversification within the more recent Mesoamerican and South American faunas. Full article

As urban areas expand, the sustainable management of municipal water becomes a critical challenge, especially in arid and semi-arid regions facing severe water scarcity. Accurate assessment of urban plant water requirements (PWR) is essential for developing sustainable landscape architecture and resilient green infrastructure. In this study, a new quantitative equation (PWR_q) was developed as a regional proof of concept to adjust reference evapotranspiration estimates for hyper-arid conditions. A Tree Morphology Coefficient (K_tm) is introduced to combine canopy features (form, height) and leaf traits (size, density) with an updated drought-resistance coefficient (K_dr). Field measurements of 277 mature trees, representing 27 native and introduced species in Riyadh and Jeddah, Saudi Arabia, were analyzed. The framework explicitly includes an empirical multiplier to account for extreme urban heat island (UHI) effects and aerodynamic canopy scaling. Instead of direct empirical validation, the PWR_q model was benchmarked against established reference indices: Water Use Classification of Landscape Species (WUCOLS) and Simplified Landscape Irrigation Demand Estimation (SLIDE), showing strong alignment with established categorical indices and structural traits. The results confirm that the morphology-based method effectively makes previously subjective classifications objective. Notably, the quantitative assessment found that the dominant introduced species require about 3.5 times more water than native species. As a proof of concept, future research should empirically validate these findings against direct physical measurements, such as sap flow sensors or lysimeters. The proposed framework presents a practical, objective decision-support tool for municipal policymakers and landscape architects to optimize species selection, implement nature-based solutions (NBS), and achieve long-term sustainability in urban greening. Full article

Conserving the genetic resources of major forest species is essential for mitigating climate risks associated with global change. Species distribution models and their projections under future emission scenarios are key tools for assessing climate-related threats to populations targeted for conservation efforts. In this study, we analyzed the populations included in the Spanish Network of Forest Genetic Conservation Units, comprising 297 units across twenty main forest tree species in Spain. We used species distribution models with high-resolution environmental data to assess habitat suitability across different climate scenarios and time periods. We introduced a Climatic Vulnerability Index to identify Genetic Conservation Units at risk of maladaptation by evaluating shifts in current conditions. Our results reveal spatial and interspecific heterogeneity in the future climatic vulnerability of the conservation network, as well as a relationship between expert-defined marginality and current climatic unsuitability under the Spanish Group model. Overall, our findings provide a basis for prioritizing conservation actions, guiding adaptive forest management, and supporting the long-term monitoring and viability of forest genetic resources under accelerating climate change. Full article

This study presents a high-resolution, multi-proxy palaeoenvironmental reconstruction of the Tövises fen at Pocsaj, Hungary, utilising lithostratigraphical, geochemical, malacological, and palynological analyses supported by radiocarbon dating. The sedimentary sequence documents the transition from a Late Glacial fluvial system (c. 19,000–16,000 cal BP) to a cut-off meander and subsequent oxbow lake, eventually evolving into a peat-forming fen. Malacological and palynological data reveal the co-occurrence of cold-tolerant Late Pleistocene elements and the early appearance of thermomesophilous taxa at the onset of the Holocene. This suggests that the favourable microclimate of the adjacent loess-covered high bank and the humid alluvial plain functioned as a cryptic refugium for temperate broad-leaved trees and associated fauna during the Late Glacial. Anthropogenic impact is traceable from the Mesolithic, characterised by Corylus management, intensifying through Neolithic agriculture to a peak during the Roman Imperial Period. Geochemical markers in the upper peat sequence reflect increased biomass and medieval habitation, while recent malacofaunal shifts indicate progressive desiccation. Despite modern drainage attempts, the Tövises fen remains a biodiversity hotspot of high conservation value, preserving relict wetland communities. Full article

Background/Objectives: Tree peony (Paeonia suffruticosa) has a short flowering period, and its regulatory mechanisms remain poorly understood. These limitations have severely constrained its industrial development. Expansins (EXPs) are key proteins that mediate cell wall loosening associated with petal expansion, yet they remain uncharacterized in tree peony. Methods: This study utilized gene family identification, key gene screening and functional research, as well as regulatory network analysis to reveal the role of the EXP family in the regulation of flower opening. Results: This study presents the first genome-wide identification of 36 PsEXP genes in tree peony, classifying them into four evolutionarily conserved subfamilies (PsEXPA, PsEXPB, PsEXLA, and PsEXLB). Promoter analysis revealed that 28 out of 36 PsEXP promoters contain gibberellin (GA)-responsive elements. Exogenous GA₃ treatment significantly promoted flower opening and upregulated eight PsEXPs, with PsEXPA4-1 showing the highest expression level and promoter GA-responsive element abundance. Subcellular localization confirmed that PsEXPA4-1 was targeted to the cell wall. Overexpression of PsEXPA4-1 in Arabidopsis led to early flowering and enlarged petals, indicating that PsEXPA4-1 had the potential to promote cell expansion, consistent with its proposed role in tree peony flower opening. Mechanistically, we identified a bHLH transcription factor, PsbHLH25, whose expression was induced by GA. Y1H and dual-luciferase assays indicated that PsbHLH25 can bind to the PsEXPA4-1 promoter. Conclusions: This study systematically characterized the EXP gene family in tree peony, revealed PsEXPA4-1 as a key effector downstream of GA promoting flower opening, and discovered PsbHLH25 as a transcriptional activator linking GA signaling to PsEXPA4-1. These findings provided important insights into GA-mediated floral opening and genetic resources for understanding the molecular mechanisms and enabling precise flowering time regulation in tree peony. Full article

Lumnitzera littorea is a rare, conservation-relevant mangrove tree with discontinuous records in southern Vietnam, but population-level genetic evidence remains limited. This study combined nuclear rDNA ITS and ISSR markers to distinguish species-level support from population-level comparisons. Can Gio was treated as the focal population, while Dong Nai, Phu Quoc, and Con Dao were used as comparison populations. The 16 study-generated ITS sequences, deposited as PZ348213–PZ348228, supported species-level separation between L. littorea and L. racemosa, with a between-species p-distance of 0.0459 and 32 fixed diagnostic sites across the 697 bp core. The ISSR matrix comprised 115 individuals and 81 loci, and population analyses were restricted to 110 L. littorea individuals. Within this dataset, Dong Nai and Can Gio showed higher ISSR diversity than Con Dao and Phu Quoc. AMOVA indicated significant differentiation among populations (Phi_PT = 0.255, p = 0.001), with 74.5% of variation retained within populations; a mainland–island grouping was also significant (Phi_PT = 0.242, p = 0.001). Repeated n = 20 subsampling retained the relative diversity pattern. The results provide a regional ISSR baseline for conservation-genetics interpretation and support broad representation of local source trees when collecting conservation material; however, they do not define formal management units, official seed-transfer zones, or deep phylogeographic history. Full article

Full-waveform hyperspectral LiDAR offers a new approach for precise forest ecological monitoring by simultaneously acquiring the three-dimensional structure and continuous spectral information of targets. However, uncertainty in the backscattering cross-section and the inseparability of the reflectance coefficient lead to systematic underestimation of multi-echo reflectance retrieved using traditional methods. This limitation significantly hinders quantitative applications. The existing multi-echo reflectance correction using neighborhood single-echo reflectance (MCNS) method provides an effective solution by establishing proportional models between similar targets, laying an important foundation for the extraction of multi-echo reflectance. However, its applicability in complex forest scenes is limited due to its dependence on specific vegetation single-echo samples. To address this, an iterative correction method based on ground reflectance baseline, namely Bare-Ground-Echo-Based Iterative Correction of Multi-Echo Reflectance for Hyperspectral LiDAR (BGE-ICMER), is proposed. Using ground single-echo reflectance as a stable baseline, a multi-target energy distribution model is constructed based on energy conservation, and backscattering cross-section proportions for each echo are iteratively solved to recover true reflectance. Validation using a high-fidelity dataset generated by the Large-Scale remote sensing data and image Simulation framework (LESS) confirmed the effectiveness of the proposed method. This dataset encompasses three typical tree species with vegetation layers ranging from two to four, incorporates micro-topographic ground surfaces and ten spectral channels from 500 to 1000 nm, thereby capturing the structural and spectral complexity of real forests. The results showed that coefficients of determination (R²) between the corrected and true reflectance exceeded 0.9560, with an RMSE below 0.0418 and MAE below 0.0360. The average relative error was reduced from 26.66% to 10.07%, representing a 62.22% improvement in accuracy. Even in the most challenging scenarios with four-layer vegetation occlusion within this dataset, no significant error accumulation occurred. These results demonstrate the robustness and effectiveness of the proposed method for multi-echo reflectance extraction. This study lays a foundation for more accurate forest biochemical attribute assessment and enables the vertical characterization of multiple targets using high-resolution spectral reflectance. Full article

Tropical forest restoration has increased in the past decades, with possible advancements given the UN declaration of the “Decade of Ecosystem Restoration”. However, robust assessments to compare ecosystem functions among restored forest stages are essential. We evaluated 13 actively restored forest stands ranging from 3 to 21 years of age and compared measures of forest biodiversity, structure, and ecosystem function to four 70+ year old “reference” stands that serve as restoration “targets” in the study region of the Premontane wet forest of Costa Rica. The restored stands were planted with an average of 13 tree species on abandoned pastures that were fallow for at least two years. Sixteen tree-stand attributes and six ecosystem function estimates were assessed, including: annual biomass (C) accumulation, N-fixation potential, threatened species conservation, and the provision of avian frugivore forage, insect habitat, and insect pollination. Using Principal Component Analysis, linear modeling, and Mahalanobis distance analyses, we learned that planting a diversity of tree species sets the stage for forest recovery at early restoration ages, with an inflection point at 15 years towards older reference forest characteristics and functions. Given that all restoration ages provided tree diversity and some level of ecosystem functions, the value of all restored stands in the landscape is notable. The assessment methods are easily employed, thereby providing an accessible tool to restoration practitioners. Full article

Understanding how P availability affects root turnover and P redistribution within plants is essential for optimizing fertilization strategies and sustaining forest growth under low-P soils. This study evaluated the effects of P fertilization on root system dynamics, plant growth, and P nutrition of Handroanthus heptaphyllus, a flowering landscape tree, cultivated in a subtropical climate. Plants were grown under two soil P levels (low and high). Plant height, stem diameter, leaf P concentration, soil P availability, total numbers of living and dead fine roots, total fine root surface area, and fine root production rate were measured at 18, 24, 30, and 36 months after planting. Phosphate fertilization increased soil P availability during the first 24 months and resulted in significant gains in plant height, stem diameter, fine root production, total surface area, and the ratio between living and dead fine roots, indicating a higher proportion of living roots relative to dead ones. Under high P availability, the greatest fine root production and surface area of living fine roots occurred in the 0–20 cm soil layer, reflecting localized P application near the plants. High P availability enhanced root system development, promoted greater soil exploration, and improved P uptake. These results indicate that under P supplementation, plants strategically invest in root growth, improving nutrient acquisition efficiency and reducing dependence on external inputs. Increased phosphorus availability enhances root growth and increases fine root production and turnover. Minirhizotron monitoring effectively captured shifts in root system dynamics driven by P availability, including enhanced root growth, increased fine root production and turnover, and improved nutrient uptake under high P, as well as limited root activity under low P conditions, indicating a more conservative strategy with reduced investment in root production. Full article

Urban trees constitute a key component of sustainable urban green infrastructure, providing ecosystem services related to climate regulation, biodiversity conservation, and human well-being. At the same time, mature and veteran trees in public spaces are frequently perceived as a safety risk due to visible structural defects, often resulting in precautionary removal decisions based solely on visual assessment. This study evaluates the applicability of acoustic tomography as a non-invasive diagnostic tool supporting sustainable urban tree management using the city of Jarocin (western Poland) as a case study. Following preliminary Visual Tree Assessment (VTA), 20 mature urban trees were identified, of which six representative specimens were subjected to detailed analysis using the PiCUS Sonic Tomograph 3. The internal condition of tree trunks, sound wave propagation velocity, residual wall thickness (t/R ratio), and structural stability were analysed in relation to species characteristics and site conditions. The results demonstrated considerable variation in the internal condition of the analysed trees and revealed that visible external defects did not necessarily correspond to a critical reduction in mechanical stability. Five out of six examined trees met or approached the accepted safety threshold (t/R ≥ 0.30), supporting their retention rather than removal. In several cases, acoustic tomography identified substantially larger zones of structurally sound wood than suggested by visual inspection alone. The findings confirm that integrating acoustic tomography into urban tree risk assessment can improve decision-making accuracy, reduce unnecessary tree removal, and support biodiversity-oriented and climate-adaptive urban green space management. The proposed approach may serve as a transferable framework for sustainable management of mature urban trees in medium-sized cities. Full article