Search Results (270)

Straw returning, a core practice in conservation tillage, promotes sustainable intensification; however, it faces challenges such as inefficient decomposition, nutrient competition, and pathogen accumulation. To address these limitations, this study aimed to develop a multifunctional microbial consortium specifically designed for straw-incorporating cropping systems. The consortium comprises four Bacillus strains with complementary enzymatic systems, isolated from diverse ecological niches. It exhibited robust lignocellulolytic enzyme production, with manganese peroxidase (7709.33 U/L), laccase (450.65 U/L), endo-β-1,4-glucanase (154.67 U/mL), and filter paper activity (309.18 U/L). The consortium significantly enhanced rice straw degradation by 37.18% and increased nitrogen (N) release by 16.13% compared to the control. Moreover, the consortium exhibited a 67.56% inhibition rate against Magnaporthe oryzae and reduced both the incidence rate and disease index of leaf blast and panicle blast. Field trials revealed increases in the rice grain yield of 9.63% and 6.94% when applied alone and 6.75% and 5.18% when co-applied with straw residues. These findings highlight the multifunctional agricultural potential of the consortium and provide a sustainable strategy to overcome the limitations of straw-incorporating farming systems. Full article

Headwater streams comprise almost 90% of global river networks, and their microorganisms play critical roles in organic matter decomposition and nutrient cycling. These functions, however, are affected by recurrent drying and rewetting. This study examined spatial variation in microbial enzyme activity tied to organic carbon degradation (β-glucosidase, phenol oxidase, and peroxidase) and nitrogen (N-acetylglucosaminidase) and phosphorus (phosphatase) mineralization in water, epilithic biofilm, leaf litter, and sediment in two intermittent streams: Gibson Jack Creek (Idaho, USA) and Pendergrass Creek (Alabama, USA), representing different climactic and physiographic settings. Microbial activity was greater in Gibson Jack Creek, where the activity of leaf litter enzymes varied along the stream network, and there were strong correlations in microbial activity between different stream habitats. Microbial activity in Pendergrass Creek showed primarily within-habitat associations. Activity in water, sediment, and biofilm showed broader spatial heterogeneity in both stream networks. Ratios of microbial activity (enzyme stoichiometry) suggested that microbial communities in both systems were primarily limited by carbon and phosphorus, although there was more spatial variation in nitrogen limitation, particularly in water and sediment at Pendergrass Creek and in biofilm at Gibson Jack Creek. These findings underscore the spatial heterogeneity and environmental sensitivity of microbial processes in intermittent streams. Full article

Purpose: This study investigated the effects of dietary bamboo leaf extract (BLE) on milk parameters and intestinal microbiota in lactating Yili mares. Methods: Twenty-four Yili mares of similar age (10 ± 2 years), weight (360.62 ± 15.23 kg) and body condition were selected for this study and randomly divided into four groups of six mares each: an untreated control group (CG) and three experimental groups (EG1, EG2, EG3) were fed a basal diet supplemented with 0, 10, 20, or 30 g/day of BLE, respectively, for 60 days. Then, horse milk composition, antioxidant activity, and immunoglobulin levels along with the relative abundance of fecal microbiota were measured. Results: Compared with the control group, supplementation with BLE for 60 days significantly improved milk yield and composition. The protein content in the EG1 was significantly higher than that in the CG, the milk yield and fat content in the EG2 was significantly higher than that in the CG, and the lactose content in the EG3 was significantly higher than that in the CG. BLE also significantly increased the milk’s antioxidant capacity, vitamin C, IgG, IgM, and IgA levels, with the antioxidant and immune properties in the EG2 being significantly higher than those in the CG. Furthermore, BLE feeding promoted communities of beneficial intestinal microbes. Bacteria associated with energy metabolism and organic matter decomposition increased significantly in BLE-fed groups, especially the EG2, which had elevated abundance of UCG-002 and the NK4A214_group. BLE also significantly reduced the abundance of Euryarchaeota, Verrucomicrobiota, Methanobacteriaceae, and Methanobrevibacter. Conclusions: Dietary supplementation with bamboo leaf extract is a safe and inexpensive way to enhance milk yield and quality and to promote the growth of beneficial intestinal microbes in Yili horses. Full article

Pesticides play key roles in modern agricultural activities. Optimizing pesticide deposition is essential for maximizing utilization efficiency and minimizing unintended environmental impacts. While electrostatic, hydrogen, and covalent interactions have been extensively studied to modulate pesticide adhesion to leaf surfaces, the potential of metal coordination bonding to enhance foliar deposition remains largely unexplored. In our work, abamectin-loaded PLA nanospheres coated in tannic acid (TA) (Abam@PLA) via the metal chelating ability of polyphenols (Abam@PLA-TA) were developed to improve abamectin retention on the surfaces of leaves. The chemical properties and morphological features of Abam@PLA-TA were characterized by scanning electron microscopy (SEM), transmission electron microscopy (TEM), Fourier transform infrared spectroscopy (FT-IR), and fluorescent imaging. The foliar retention of Abam@PLA-TA demonstrated that the tannic acid coating could significantly improve the adhesion ability and deposition efficiency of pesticides for crop leaves, which was mainly attributed to the hydrogen bonds between the polyphenols of TA and the polar groups of the wax layer. Moreover, Abam@PLA-TA exhibited better photostability capacity compared to the abamectin technical concentrate, which helps to protect light-sensitive pesticides from ultraviolet (UV) decomposition. This strategy opens up a simple but powerful avenue for the design of foliage adhesive systems and a new opportunity for the efficient utilization of pesticides. Full article

Bacterial diseases of forest trees represent an increasing threat to ecosystem health and the sustainability and resilience of forest management, particularly under changing climate conditions. One of the key yet still insufficiently understood adaptive mechanisms of pathogens is biofilm formation—a structured community of bacterial cells embedded in a matrix of extracellular polymeric substances (EPS), which provides protection against stress factors, biocides, and the host’s defensive responses such as antimicrobial compounds or immune reactions. This paper presents a comprehensive review of current knowledge on the role of biofilms in the bacterial pathogenesis of forest trees, covering their formation mechanisms, molecular regulation, and ecological significance. Four key stages of biofilm development are discussed—adhesion, microcolony formation, EPS production, and dispersion—along with the roles of quorum sensing systems and c-di-GMP-based signaling in regulating these processes. Examples of major tree pathogens are presented, including Pseudomonas syringae, Erwinia amylovora, Xylella fastidiosa, the Brenneria–Gibbsiella complex associated with Acute Oak Decline (AOD) and Lonsdalea populi. Biofilm formation is shown to play a crucial role in the colonization of xylem, leaf surfaces, and tissues undergoing necrosis, where biofilms may stabilize decomposition zones and support saprophytic–pathogenic transitions. In the applied section, the concept of “biofilm-targeted control” is discussed, encompassing both chemical and biological strategies for disrupting biofilm structure—from quorum-sensing inhibitors and EPS-degrading enzymes to the use of biosurfactants and antagonistic microorganisms. The need for in situ research in forest environments and the adaptation of advanced imaging (CLSM, micro-CT) and metagenomic analyses to tree systems is also emphasized. This review concludes that biofilms are not merely a physiological form of bacterial organization but a complex adaptive system essential for the survival and virulence of pathogens in forest ecosystems. Understanding their functions is fundamental for developing sustainable and ecologically safe phytosanitary strategies for forest protection. Full article

A trial was conducted from 2017 to 2023 in a 0.2 ha irrigated vineyard located in a semiarid area of southeastern Spain, using field-grown young vines (0–6 years old) of Vitis vinifera L. cv. Monastrell grafted onto three rootstocks: 140Ru, 161-49C, and 110R. The main objective was to evaluate the effect of early co-inoculation in the field using commercial microbial inoculants containing arbuscular mycorrhizal fungi (AMF), plant growth-promoting rhizobacteria (PGPR), and a mycorrhizal helper bacterium (MHB) on young vine performance. We assessed the impact of microbial inoculation and its interaction with the rootstock on soil environment, plant water relations, leaf gas exchange, plant nutrition, growth, yield, and berry quality. Mycorrhizal colonization rates in root samples showed similar values in inoculated and non-inoculated vines across all of the rootstocks; however, inoculated vines grafted onto 140Ru showed significantly higher concentrations of total glomalin in the soil compared to their non-inoculated counterparts. Microbial inoculation altered the soil environment, leading to increased oxygen diffusion rate (161-49C), organic matter decomposition rate (140Ru), soil CO₂ flux (110R, 140Ru), and soil H₂O flux (110R) values in the rhizosphere of inoculated vines. Additionally, inoculated vines grafted onto 140Ru and 161-49C exhibited improved vegetative and reproductive development, enhancing productive water use efficiency (WUE_yield), whereas inoculated vines on 110R showed poorer soil–plant water relations, growth, yield, and WUE_yield compared to non-inoculated vines. Microbial inoculation also led to a significant decrease in must phenolic content, particularly in 140Ru, unlike 110R and 161-49C. These findings indicate that early microbial inoculation had a rootstock-dependent impact on the performance of young grapevines. Full article

We studied differences in the decomposition rate between Pinus merkusii Jungh. et de Vriese (tusam) leaves, a representative of needle leaf litter, and Diospyros celebica Bakh. (ebony) leaves, a representative of broadleaf litter, in three forest communities (Karst, Lowland, Pine) on the island of Sulawesi, Indonesia, and identified their determinants. Twenty-four 1 m × 1 m quadrats were set up in each forest community to observe the in situ decomposition process. Near each quadrat, 1 m² litter traps were set to monitor litter production. In addition, 30 litter bags containing tusam leaves and 30 litter bags containing ebony leaves were spread in the three forest communities, in both the dry and wet seasons, to observe their decomposition rate during each season. The ANOVA test showed that the one-year in situ Decomposition Rate Constant (k) was significantly highest in the Karst forest (0.0921/year), followed by the Lowland forest (0.0700/year), and the lowest in the Pine forest (0.0277/year). During the dry season, the mean k-value of tusam leaves was significantly faster than ebony leaves in Karst (0.7162/6 months for tusam, 0.3840/6 months for ebony) and Lowland forests (0.3472/6 months for tusam, 0.1017/6 months for ebony), but on the contrary, it is slower in the Pine forest (0.0498/6 months for tusam, 0.0745/6 months for ebony). During the wet season, there was no significant difference between the mean k-value of tusam leaves compared to ebony leaves in the Karst (0.5217/4 months for tusam, 0.4859/4 months for ebony) and Lowland (0.2397/4 months for tusam, 0.2098/4 months for ebony) forests, but in the Pine forest, the mean k-value of ebony leaves was significantly higher than that of tusam leaves (0.0942/4 months for tusam, 0.1650/4 months for ebony). This study explains that the decomposition process of leaf litter is complex, species-specific, and is controlled by a combination of factors. Extrinsic factors play a more critical role than intrinsic factors in determining the k-value. The low rate of decomposition of tusam leaves under its mother tree stands is not caused by intrinsic factors, but rather by extrinsic factors that inhibit the growth of decomposing agents. Full article

Labyrinthulomycetes protists play important roles in organic matter decomposition and nutrient cycling in marine ecosystems. To better understand their distribution and potential ecological functions in Caofeidian seagrass beds of the Bohai Sea, we conducted high-throughput sequencing of samples collected from multiple habitats, including leaves (L), rhizosphere (R), sediments (S), and seawater (W). Our results revealed distinct habitat-specific patterns of community composition. Oblongichytrium and Stellarchytrium were dominant in certain samples, exhibiting clear differences across stations. Oblongichytrium showed particularly high abundance in leaf and seawater samples, likely reflecting the availability of particulate and dissolved substrates enriched by seagrass beds. In the rhizosphere, Sicyoidochytrium, Stellarchytrium and Labyrinthula were enriched, whereas unclassified Labyrinthulomycetes and Thraustochytriaceae lineages prevailed in seawater and specific leaf samples. Notably, a substantial proportion of sequences corresponded to unclassified lineages, potentially representing uncultured “seagrass-associated” taxa. Compared with previous reports, our study revealed both a significantly higher abundance of Stellarchytrium and a remarkably greater proportion of unclassified lineages, suggesting unique features of Labyrinthulomycetes communities in the Caofeidian seagrass ecosystem. These findings provide new insights into the ecological roles of Labyrinthulomycetes in seagrass beds and offer an important reference for future taxonomic and functional studies of this group. Full article

Understory vegetation, particularly dwarf bamboo, plays a crucial role in regulating forest nutrient cycles by intercepting litter and altering decomposition processes, yet its overall impacts remain understudied and insufficiently quantified. This study employs a combination of field surveys and decomposition bag experiments to investigate how understory dwarf bamboo (Fargesia decurvata) alters the spatial–temporal patterns of leaf litter production and decomposition. We found that the dwarf bamboo intercepted more than 25% of canopy litterfall, altering its spatial distribution and reducing decomposition efficiency in the bamboo crown (BC). Leaf trait-decomposition relationships differed strongly across habitats, being positive for saturated fresh weight (SFW), leaf thickness (LFT), and leaf area (LA) and dry weight (DW) in bamboo habitats but weaker in the bamboo-free habitat (NB). Potassium release was significantly higher in the BC treatment, whereas carbon release showed the opposite trend. In contrast, nitrogen and phosphorus exhibited net enrichment across all treatments, with phosphorus enrichment being slower in BC than in bamboo-covered ground surface (BG) and NB. Our results demonstrate that the understory dwarf bamboo reshapes the spatial distribution of litter and nutrient release dynamics during decomposition, resulting in element-specific nutrient release patterns. These findings provide mechanistic insights into how understory dwarf bamboo mediates nutrient cycling dynamics in forest communities. Full article

To address environmental pollution issues and optimize the utilization of waste biomass resources, this study proposes a novel eco-friendly sound-absorbing material based on maple leaf waste and tests its sound absorption performance. The fibers were extracted from maple leaf waste through a wet decomposition and grinding process. Metallurgical microscopy was employed to observe the microstructural characteristics of maple leaf fibers to identify the potential synergistic effect. The effects of two key factors—sample thickness and mass density—on sound absorption performance were investigated. The sound absorption coefficients were measured using the transfer function method in a dual-microphone impedance tube to evaluate their sound-absorbing performance. Experimental results demonstrate that the prepared maple leaf fibers, as acoustic materials, exhibit excellent acoustic performance across a wide frequency range, with an average sound absorption coefficient of 0.7. Increasing sample thickness improves the sound absorption coefficient in low- and mid-frequency ranges. Additionally, increased sample mass density was found to enhance acoustic performance in low- and mid-frequency bands. This study developed an eco-friendly material with lightweight and efficient acoustic absorption properties using completely biodegradable maple leaf waste. The results provide high-performance, economical, and ecologically sustainable solutions for controlling building and traffic noise while promoting the development of eco-friendly acoustic materials. Full article

Terrestrial cross-boundary inputs of leaf litter serve as a critical foundation for secondary productivity in freshwater ecosystems. The regulatory mechanisms of tannins in leaf litter on degradation rates under submerged conditions remain unclear. This study employed leaf litter from low-tannin plants Osmanthus fragrans (A) and Canna glauca (B) as decomposition substrates, with the high-tannin species Myriophyllum verticillatum (C) incorporated to adjust tannin levels. A 140-day hydroponic degradation experiment was conducted under controlled temperature and dark conditions, which included four mixed litter treatments with a gradient of tannin additions (AB as the control, 0 g; ABC1: 0.5 g; ABC2: 2.5 g; ABC3: 4.5 g) along with two single-species treatments (A and B). The following results were found: (1) Low tannin levels (ABC1) promoted degradation rates of A and B (increased by 1.33–12.70%), whereas high tannin (ABC3) inhibited decomposition (decreased by 6.21–6.82%). (2) Tannin–protein complexes reduce nitrogen bioavailability and inhibit nitrification, thereby disrupting the nitrogen cycle in aquatic systems. In ABC3, total nitrogen content in A and B litter increased by 17.69–26.46% compared to AB, with concurrent 59.29% elevation in water NH₄⁺-N concentration. (3) High tannin induced dominance of oligotrophic stress-resistant bacterial communities (e.g., Treponema) through nutrient limitation and toxicity stress; however, their low metabolic efficiency reduced overall decomposition efficiency. Research reveals that the ecological benefits of plant secondary metabolites outweigh their nutritional quality attributes. Full article

Although rainfall is a major determinant of soil moisture content (SMC), various factors affect SMC. The effects of these environmental factors contribute to spatial heterogeneity in SMC, which influences diverse ecological processes. To better understand the dynamics in SMC, litter and slope gradient should be considered. To this end, we analyzed the impacts of litter and slope gradient on SMC from 2020 to 2021 on Mt. Jeombong, located in a temperate deciduous broadleaf forest. We classified the study period into foliage (with a developed canopy) and non-foliage (after leaf fall) seasons. Our results indicated that SMC was affected by slope gradient and litter layer. Rainfall absorption occurred more at gentle slope, leading to higher SMC. Additionally, rainfall absorption was interpreted as being intercepted by the litter layer. Consequently, the correlation coefficient between SMC increment and rainfall was lower in the non-foliage season (R² = 0.37–0.56) than in the foliage season (R² = 0.72–0.84). With temporal progression, however, SMC response to rainfall increased where the litter was thickly accumulated, suggesting that litter interception was gradually diminished by decomposition. In this study, spatial heterogeneity in the litter layer and slope gradient substantially influenced the supply of soil moisture from rainfall. Full article

Karst rivers are increasingly contaminated by both heavy metals and nanoplastics, yet their combined impact on riparian litter decomposition remains unresolved. We conducted a 90-day microcosm experiment using Miscanthus floridulus leaf litter collected from the Donghe River, Jishou, China, and exposed it to Pb (1 mg L⁻¹), polystyrene nanoplastics (10 and 100 µg L⁻¹), and their combinations. Pb alone modestly inhibited mass loss (61.0%) and respiration, while NP10 significantly accelerated decomposition (67.0%), and NP100 suppressed it (60.4%); co-exposure produced non-monotonic, concentration-dependent effects. Enzyme stoichiometry revealed that all treatments intensified nitrogen limitation but alleviated carbon limitation through reduced microbial activity. Bacterial communities, dominated by Pseudomonadota, exhibited remarkably stable phylum-level composition, high network complexity, and identical keystone taxa across all treatments, indicating strong functional redundancy and resilience. In contrast, fungal communities suffered severe declines in Basidiomycota abundance, collapsed network stability, and a single keystone taxon, underscoring their vulnerability. βNTI–RC_bray analyses demonstrated that stochastic processes (>50%) overwhelmingly governed both bacterial and fungal assembly, with only marginal deterministic shifts. Collectively, our findings highlight that bacteria—not fungi—serve as the primary decomposers under Pb–NP co-stress and that stochastic assembly, coupled with bacterial redundancy, buffers ecosystem function against emerging mixed pollutants in subtropical riverine systems. Full article

Poplar (Populus L. species), a fast-growing temperate species, forms plantations with high productivity and biomass, with its litter sustaining key functions in nutrient cycling, microbial diversity, and carbon storage. Litter microbial communities drive decomposition, particularly in early stages, this initial phase is characterized by the leaching of water-soluble carbon and nutrients from the litter, which creates a readily available resource pulse that facilitates rapid microbial colonization and activation. This process is followed by the activation of microbial enzymes and the immobilization of nutrients, collectively initiating the breakdown of more recalcitrant litter materials. Under rising global nitrogen deposition, we conducted a field randomized block experiment in 13-year-old pure poplar (Populus deltoides L. ‘35’) stands, with three nitrogen addition treatments: N0 (0 g N·m⁻²·yr⁻¹), N2 (10 g N·m⁻²·yr⁻¹), and N4 (30 g N·m⁻²·yr⁻¹). In the initial phase of litter decomposition, we measured the soil properties and litter traits, the litter microbial community composition, and its taxonomic and phylogenetic diversity indices. The results indicate that nitrogen addition altered microbial biomass carbon (MBC), microbial biomass nitrogen (MBN), soil NO₃⁻-N, and accelerated litter decomposition rates. The microbial community in leaf litter responded to nitrogen addition with increased phylogenetic clustering (higher OTU richness and NRI), which suggests that environmental filtering exerted a homogenizing selective pressure linked to both soil and litter properties, whereas the microbial community in branch litter responded to nitrogen addition with increased taxonomic diversity (higher OTU richness, Shannon, ACE, and Chao1), a pattern associated with litter properties that likely alleviated nitrogen limitation and created opportunities for more taxa to coexist. The observed differences in response stem from distinct substrate properties of the litter. This study elucidates microbial taxonomic and phylogenetic diversity responses to nitrogen addition during litter decomposition, offering a scientific foundation for precise microbial community regulation and sustainable litter management. Full article

This study proposes an Automatic Branch Modeling (ABM) framework that combines AdTree and AdQSM algorithms to reconstruct individual tree models and estimate timber volume from fused Hand-held Laser Scanners (HLS) and Unmanned Aerial Vehicle Laser Scanners (UAV-LS) point cloud data. The research focuses on two 50 × 50 m primary tropical rainforest plots in Hainan Island, China, characterized by dense and vertically stratified vegetation. Key steps include multi-source point cloud registration and noise removal, individual tree segmentation using the Comparative Shortest Path (CSP) algorithm, extraction of diameter at breast height (DBH) and tree height, and 3D reconstruction and volume estimation via cylindrical fitting and convex polyhedron decomposition. Results demonstrate high accuracy in parameter extraction, with DBH estimation achieving R² = 0.89–0.90, RMSE = 2.93–3.95 cm and RMSE% = 13.95–14.75%, while tree height estimation yielded R² = 0.89–0.94, RMSE = 1.26–1.81 m and RMSE% = 9.41–13.2%. Timber volume estimates showed strong agreement with binary volume models (R² = 0.90–0.94, RMSE = 0.10–0.18 m³, RMSE% = 32.33–34.65%), validated by concordance correlation coefficients (CCC) of 0.95–0.97. The fusion of HLS (ground-level trunk details) and UAV-LS (canopy structure) data significantly improved structural completeness, overcoming occlusion challenges in dense forests. This study highlights the efficacy of multi-source LiDAR fusion and 3D modeling for precise forest inventory in complex ecosystems. The ABM framework provides a scalable, non-destructive alternative to traditional methods, supporting carbon stock assessment and sustainable forest management in tropical rainforests. Future work should refine individual tree segmentation and wood-leaf separation to further enhance accuracy in heterogeneous environments. Full article