Search Results (328)

The mean annual change in aboveground biomass (ΔAGB) is a pivotal indicator for assessing forest carbon cycle dynamics. This study analyzed 791 independent Abies Mill. forest patches across China to elucidate their driving mechanisms by integrating abiotic, anthropogenic, and biotic factors. We employed a spatially explicit framework, including spatial error regression and structural equation modeling (SEM), to account for significant spatial autocorrelation (Moran’s I = 0.375, p < 0.001). Our results show that abiotic factors predominantly dictate ΔAGB, with soil fertility (pH and Total Nitrogen), elevation (DEM), and soil physical properties (Coarse Fragments and Thickness) explaining the majority of deterministic variance. This relatively low explanatory variance (marginal R² = 0.09) likely reflects the high environmental stochasticity inherent in alpine ecosystems. Specifically, soil fertility exerted the strongest positive influence (Std. Estimate = 0.33), while elevation and soil physical constraints were the primary limiting factors. Biotic factors (Stand Age, Height, and Tree Cover) played a subordinate role, contributing only a marginal 2% gain in explained variance (increasing marginal R² from 0.07 to 0.09). Path analysis revealed an “environmental filtering” hierarchy where abiotic factors shape stand structure, which in turn has limited impact on growth dynamics. These findings underscore that carbon management in alpine forests should prioritize habitat quality conservation over simple biotic structural manipulation. Full article

Litter input, including aboveground and belowground plant residues such as leaves, branches, and roots, is a major pathway of carbon return to forest soils. The prevailing paradigm in forest carbon management emphasizes litter input as the primary driver of soil organic carbon (SOC) sequestration. Here, litter input refers specifically to experimental litter manipulation, including litter-addition and litter-removal treatments. Although numerous experimental studies have examined the effects of litter manipulation on SOC, several limitations remain. By synthesizing 1555 global observations, we demonstrate that climate zone, not litter manipulation per se, is the dominant moderator of SOC fraction responses. Litter addition significantly increased labile fractions (light fraction: +60%) but left MAOC largely unchanged. Conversely, litter removal depleted labile pools yet failed to destabilize MAOC. This universal inertia of MAOC challenges the assumption that litter management directly enhances long-term carbon stability. Furthermore, we reveal a critical climate dependency: tropical forests show attenuated carbon gains under litter addition, while temperate systems are more responsive. Our findings necessitate a paradigm shift from uniform litter-based strategies to climate-zone-specific forest management, prioritizing the protection of existing soil carbon in vulnerable biomes over indiscriminate litter augmentation. Full article

At present, commonly used vegetable pot seedling planters can be divided into two categories: one has a complex structure and high manufacturing cost, and the other has a simple structure but poor planting quality. In order to solve this problem, an open-hinge four-bar-mechanism planting manipulator is designed, which has many advantages, such as a simple structure, strong force transfer performance, and the ability to achieve complex trajectory curves. The physical characteristics of pot seedlings are measured; this provides a basis for the structural and dimensional design of the planter and the shape design of the duckbill. According to the analysis of the planting process, the design requirements of the planting mechanism are formulated. The motion path of the mechanism and the motion of each pair are planned and designed; a planetary gear train is used to restrain the rotating pair consisting of connecting rod 1 and connecting rod 2; a cam high pair mechanism is used to restrain the rotating pair consisting of connecting rod 2 and connecting rod 3; and a cam linkage mechanism is used to control the opening and closing action of the duckbill. Finally, a single-degree-of-freedom fully mechanical planting mechanism is designed. The experimental results show that the trajectory of the initial soil entry point of the planting mechanism is consistent with the design requirements and theoretical simulation results. In the transplanting experiment, the rate of qualified planting erectness was 94.79%, among which the rate of excellent planting erectness was 92.45%, and the mechanism has high reliability. The design of this mechanism offers a fully automatic pot seedling planting method, which can provide a reference for research on the full automation of transplanting equipment. Full article

Plant-mediated CH₄ transport can enhance ecosystem CH₄ emission by transporting soil-produced CH₄. This pathway can exceed diffusion and ebullition as the dominant CH₄ emission route. However, limited studies have investigated the morphological and anatomical factors influencing CH₄ transport in plants. Through a series of manipulative experiments on the shoots and roots, this study examines the role of root and shoot structures in CH₄ transport and release in six widespread wetland species: Carex rostrata Stokes, Carex lasiocarpa Ehrh., Carex aquatilis Wahlenb., Iris pseudacorus L., Juncus effusus L., and Alocasia odora (Lodd.) Spach. CH₄ flux from all investigated species dropped significantly after clipping fine roots, while it did not change significantly after removing coarse roots. Shoot clipping and sealing significantly decreased CH₄ flux from the investigated Carex species, but not from the other species. Our results demonstrate the important role of fine roots in controlling CH₄ flux, whereas coarse roots play a minor role. Leaf blades are the major release site of CH₄ from Carex species, while micropores at the shoot base are the primary release site of CH₄ from the other species. Our study suggests that integrating plant-specific anatomical and morphological characteristics into global methane models is crucial to better predict and mitigate climate change impacts. Full article

Soil nutrients and water are often distributed heterogeneously in space, yet how plant roots forage in response to such heterogeneity and how their strategies relate to functional traits remain poorly understood. Here, we conducted an indoor pot experiment manipulating water and nutrient supply in both homogeneous and heterogeneous patch patterns using seedlings of four tree species, focusing on root functional traits and foraging strategies. The results indicate that root foraging behavior exhibits both resource specificity and species specificity: roots tend to proliferate toward nutrient-rich and low-water patches as an adaptive strategy. Although no strict dichotomy was observed between high foraging scale (low precision) and low foraging scale (high precision) strategies under heterogeneous conditions, fine-rooted species (Acer truncatum and Koelreuteria paniculata) exhibited traits leaning toward “precise foraging”, whereas coarse-rooted species (Prunus davidiana and Quercus variabilis) tended toward a conservative “random walk” pattern, with no trade-off between root foraging scale and precision. Root morphological traits exerted significant nonlinear regulation on foraging scale: root biomass foraging scale (FS_RB) correlated positively with root diameter (RD) but negatively with specific root length (SRL) and specific root area (SRA); root length foraging scale (FS_RL) correlated positively with root length (RL), root tip number (RTN), SRL, and SRA. In contrast, root morphological traits could not explain the variation in foraging precision, suggesting that foraging precision constitutes another distinct dimension in root-trait space. In summary, this study provides key insights into the foraging strategies of plant roots in heterogeneous environments, expanding our understanding of the multidimensionality of root functional traits. Full article

The Qinghai–Tibet Plateau is undergoing rapid warming and humidification, with altered precipitation regimes increasingly affecting soil nitrogen cycling and N₂O emissions. Denitrification—a key nitrogen transformation pathway—is particularly sensitive to these hydrological changes. Here, we investigated the response of nirK-type denitrifying microbial communities to altered precipitation in an alpine wetland on the northern shore of Qinghai Lake. Using a long-term precipitation manipulation platform with five gradients (ambient, ±25%, and ±50%), we integrated high-throughput sequencing with bioinformatics to systematically assess community shifts. Short-term precipitation treatments did not significantly alter alpha diversity, but markedly restructured community composition. Extreme wetting (+50%) increased within-group heterogeneity. At the phylum level, Proteobacteria remained dominant across all treatments, whereas extreme drought (−50%) suppressed Planctomycetes. At the genus level, Ochrobactrum was enriched under reduced precipitation, while Rhodopseudomonas increased under increased precipitation. Functional predictions indicated that reduced precipitation enhanced nitrogen fixation potential, whereas increased precipitation favored nitrate respiration. Soil pH and carbon fractions were the key environmental filters driving community variation. Ecological process analysis revealed that community assembly was entirely governed by deterministic processes, specifically variable selection. Together, these findings elucidate how precipitation shifts reconfigure the structure and functional potential of denitrifying microbial communities in alpine wetlands, primarily via changes in soil pH and moisture under variable selection. This work provides critical insights into microbial regulation of the nitrogen cycle on the Tibetan Plateau under ongoing climate change. Full article

Hemp (Cannabis sativa L.) is an important crop, yet little is known about how herbivory and soil microbial communities interact to influence plant performance. In this study, two hemp cultivars, BaOx and Cherry Citrus, were grown under identical greenhouse conditions and exposed to naturally occurring background populations of the two-spotted spider mite (Tetranychus urticae). Plant traits were measured, and rhizosphere soil was sampled for 16S rRNA gene sequencing to compare bacterial community composition and diversity between cultivars. Spider mite injury was assessed using a standardized 0–5 visual damage scale commonly applied in integrated pest management studies. Although the cultivars did not differ significantly in growth traits, Cherry Citrus experienced significantly less spider mite damage than BaOx, suggesting greater tolerance or resistance to herbivory under shared conditions. Rhizosphere bacterial communities differed markedly between cultivars despite identical soil and environmental conditions. BaOx rhizospheres were enriched in Actinobacteria, including taxa associated with decomposition and antimicrobial compound production, whereas Cherry Citrus rhizospheres were enriched in Alphaproteobacteria, particularly nitrogen-cycling and root-associated taxa such as Rhizobium and Reyranella. Alpha diversity metrics did not differ between cultivars; however, beta diversity analyses revealed significant cultivar-level separation, particularly in phylogenetic community structure. Because herbivore pressure and microbial communities were not experimentally manipulated, this observational study identifies ecological associations rather than direct causal relationships. Nevertheless, the results demonstrate that hemp cultivar identity is associated with distinct rhizosphere microbiomes and differential susceptibility to spider mite damage. These findings highlight the potential for integrating cultivar selection and microbiome-informed strategies into sustainable pest management programs for hemp. Full article

The soil–water interface (SWI) represents a critical biogeochemical hotspot where steep physicochemical gradients across millimetre-to micrometre-scales create diverse ecological niches controlling nutrient cycling, carbon stabilisation, and contaminant transformation. This review synthesises emerging understanding of micro-scale microbial dynamics, biofilm architecture, and functional processes shaping SWI ecosystems. We examine redox stratification driving microbial community assembly, biofilm-mediated nutrient trapping and soil aggregate stabilisation, and dynamic drivers including hydrological fluctuations, viral lysis, and differential transport at gas–water versus solid–water interfaces. Advanced methodologies, microsensor profiling, cryo-sectioning, spatially resolved metatranscriptomics, and non-destructive imaging, now enable unprecedented resolution of SWI microhabitat chemistry and microbial organisation. Horizontal gene transfer within interface biofilms accelerates adaptive responses to environmental stressors. Integration of micro-scale observations into ecosystem-level models remains challenging but essential for predicting soil carbon sequestration, contaminant fate, and microbial resilience under climate change. Strategic SWI management through biofilm engineering and controlled redox manipulation offers novel pathways for sustainable agriculture and bioremediation, though it requires careful balance of multiple ecosystem functions. Full article

Lupinus angustifolius is an important leguminous ornamental species, but its productivity is often compromised by alkaline soil stress. GsEXPA8, an expansin gene identified in wild soybean (Glycine soja), has been implicated in alkali stress tolerance. In this study, we examined how heterologous expression of GsEXPA8 in lupinus affects its biochemical, molecular, and rhizospheric responses to alkali stress. Under NaHCO₃-induced alkaline conditions, transgenic lines overexpressing GsEXPA8 displayed improved leaf vigor, greater root biomass and length, elevated activities of antioxidant enzymes (CAT and POD), increased proline accumulation, and reduced malondialdehyde levels compared to the wild type. Expression analysis revealed time-dependent up-regulation of several alkali-responsive genes (LaSOS1, LaNCED3, LaMYB39, LaNAC56, LaNHX6, and LaP5CS). Moreover, the rhizosphere microbial community was significantly restructured, with a marked increase in beneficial microbial taxa such as Pseudomonas and Lysobacter. We also found that the endogenous lupinus homolog LaEXPA8 is alkali-inducible. Overexpression of LaEXPA8 similarly enhanced alkaline tolerance, whereas CRISPR/Cas9 knockout lines showed no clear phenotypic alteration, suggesting potential functional redundancy within the expansin family. Notably, LaEXPA8 and GsEXPA8 differed in their temporal regulation of downstream genes, indicating both conserved and distinct regulatory roles. Our results demonstrate that GsEXPA8 improves alkali tolerance in lupinus through integrated mechanisms: promoting root growth, enhancing antioxidant and osmotic adjustment capacity, dynamically modulating stress-related gene expression, and enriching beneficial rhizosphere microbiota. This work provides the critical report of modifying alkali tolerance by manipulating an expansin gene alongside the associated rhizosphere microbiome, offering a combined strategy for breeding stress-resistant ornamentals. Full article

Global climate change is intensively altering precipitation regimes, with profound consequences for the structure and function of various terrestrial ecosystems. Soil microbes are a key driver of organic matter decomposition and nutrient cycling; however, their response mechanisms to precipitation variations in fragile ecosystems remain poorly understood. We conducted an in situ precipitation manipulation experiment in a savanna ecosystem within the Yuanjiang dry-hot valley of southwest China since January 2014. We established three treatments: a control plot with natural precipitation (NP), precipitation exclusion by 50% (PE50), and precipitation addition by 50% (PA50). Soil samples were collected in mid-April and mid-August 2025. Using high-throughput sequencing technology, we systematically examined how precipitation variations affected soil microbial community structure and the underlying environmental drivers. The study results showed that both PA50 and PE50 treatments significantly altered the α- and β-diversity of bacterial and fungal communities (PERMANOVA, p < 0.05), marking a clear separation in overall soil microbial community structure among treatments. The bacterial community response was more pronounced to precipitation variations than the fungal community, and exhibited a non-linear response pattern. Both PE50 and PA50 treatments increased bacterial richness. In contrast, shifts in fungal diversity were season-dependent. The analysis results of Linear discriminant analysis Effect Size (LEfSe) revealed that the PE50 treatment enriched drought-tolerant taxa, such as Actinobacteria and Ascomycota. Conversely, the PA50 treatment favored moisture-preferring taxa, including Acidobacteria and Basidiomycota. Redundancy analysis (RDA) identified soil moisture (SM), dissolved organic nitrogen (DON), and soil organic carbon (SOC) as the key factors driving these community shifts. The relative importance of these drivers varied seasonally: SM was dominant in the dry season, while SOC and nutrient-related factors prevailed during the rainy season. This study elucidates the non-linear and seasonally contingent response mechanisms of soil microbial communities to precipitation variations in a fragile savanna ecosystem. Our findings provide a critical theoretical framework for predicting how the structure and function of vulnerable ecosystems may evolve under future climate change. Full article

Soil-borne oomycetes, such as Phytophthora and Pythium species, are highly destructive pathogens responsible for severe diseases in crops, ornamentals, and natural ecosystems. These pathogens can persist in soil for many years, making them particularly difficult to control. To establish infection, they deploy a diverse arsenal of effector proteins that manipulate host immune responses, disrupt vital cellular functions, and may influence the rhizosphere microbiome to facilitate successful colonization. Phytophthora relies heavily on RxLR effectors to disrupt intracellular immunity, while Pythium species predominantly deploy necrosis-inducing NLPs and cell wall-degrading enzymes, with no confirmed canonical RxLR effectors, suggesting distinct evolutionary strategies. This review aims to explore the detailed mechanisms of plant-pathogen interaction. In recent years, significant progress has been made in understanding the molecular dialogue between pathogens and their hosts, particularly how pathogenic species such as Phytophthora and Pythium manipulate plant immunity through effector secretion, and how plants counteract by activating defense mechanisms at molecular, cellular, and biochemical levels, including changes in hormone signaling, reactive oxygen species (ROS) dynamics, and defense gene expression. The review also outlines emerging disease management strategies and integrative approaches guided by effector biology and microbiome insights. Full article

Drought can alter plant nutrient constraints, yet it remains uncertain whether macronutrient limitation hierarchies primarily reflect intrinsic responses or can be reshaped by targeted treatments. In a pot experiment with maize (Zea mays L.), we tested elemental sulfur (ES) and salicylic acid (SA) applied either as foliar sprays or soil amendments under two soil water regimes (30% vs. 60% field water capacity, FWC). Six treatments were evaluated (control, ES-foliar, SA-foliar, SA-soil, ES-soil, and ES + SA-soil; n = 72). Regression tree analysis of data indicated sulfur-potassium co-dominance under drought (24.6% importance each; R² = 0.914), while untreated controls showed nitrogen dominance (27.1%), confirming the S-K pattern is treatment-mediated. Under optimal irrigation (FWC 60%), nutrient importance was balanced across treatments (N, P, K, S; ~22–23%; R² = 0.991). ES + SA applied to soil produced the greatest drought tolerance, increasing dry biomass by 56% at FWC 30%, whereas ES-soil maintained favorable N/S ratios (9.64–9.86). Redundancy analysis confirmed that water availability explained 63.4% of nutrient variance and revealed significant Treatment × FWC interactions. These findings reveal that nutrient hierarchies can be strategically manipulated through targeted fertilization, representing a nutrient management approach for enhancing drought tolerance. Full article

Nitrogen (N) deposition poses a multi-pronged threat to the carbon (C)-regulating services of moss understories. For forest C-cycle modeling under increasing N deposition, failure to mechanistically incorporate the moss-mediated processes risks severely overestimating the C sink potential of global forests. To explore whether and how N input affects the moss-mediated CH₄ and carbon dioxide (CO₂) fluxes, a five-year field measurement was performed in the N manipulation experimental plots treated with 22.5 and 45 kg N ha⁻¹ yr⁻¹ as ammonium chloride for nine years under a well-drained temperate forest in northeastern China. In the presence of mosses, the average annual CH₄ uptake and CO₂ emission in all N-treated plots ranged from 0.96 to 1.48 kg C-CH₄ ha⁻¹ yr⁻¹ and from 4.04 to 4.41 Mg C-CO₂ ha⁻¹ yr⁻¹, respectively, with a minimum in the high-N-treated plots, which were smaller than those in the control (1.29–1.83 kg C-CH₄ ha⁻¹ yr⁻¹ and 4.82–6.51 Mg C-CO₂ ha⁻¹ yr⁻¹). However, no significant differences in annual cumulative CO₂ and CH₄ fluxes across all treatments occurred without moss cover. Based on the differences in C fluxes with and without mosses, the average annual moss-mediated CH₄ uptake and CO₂ emission in the control were 0.77 kg C-CH₄ ha⁻¹ yr⁻¹ and 2.40 Mg C-CO₂ ha⁻¹ yr⁻¹, respectively, which were larger than those in the two N treatments. The N effects on annual moss-mediated C fluxes varied with annual meteorological conditions. Soil pH, available N and C contents, and microbial activity inferred from δ¹³C shifts in respired CO₂ were identified as the main driving factors controlling the moss-mediated CH₄ and CO₂ fluxes. The results highlighted that this inhibitory effect of increasing N deposition on moss-mediated C fluxes in the context of climate change should be reasonably taken into account in model studies to accurately predict C fluxes under well-drained forest ecosystems. Full article

Microfluidics has emerged as a powerful enabling technology in plant science, offering unprecedented control over microscale environments for the cultivation, manipulation, and analysis of plant cells, tissues, and organs. This review provides a comprehensive overview of the development and application of microfluidic systems in plant physiology and development studies. We categorize the platforms based on their structural designs and biological targets—from single-cell trapping devices and droplet-based screening systems to organ-on-a-chip and root–microbe interaction modules. Key applications include live-cell imaging, real-time monitoring of stress responses, microenvironment simulation, and high-throughput phenotyping. Particular attention is given to microfluidic investigations of plant mechanobiology, chemotropism, and cell-to-cell communication, as well as their integration with biosensors, electrophysiological tools, and environmental control systems. We also examine current limitations related to material compatibility, device scalability, and biological complexity, and highlight emerging solutions such as modular design, interdisciplinary integration, and soil-on-a-chip systems. By addressing both fundamental research needs and practical agricultural challenges, microfluidic technologies offer a transformative path toward precision plant science and sustainable crop innovation. Full article

Continuous monoculture of Panax notoginseng leads to severe replant disease, yet the mechanisms by which root exudates mediate rhizosphere microbiome assembly and pathogen enrichment remain poorly understood. Here, we demonstrate that long-term root exudate accumulation acts as an ecological filter, driving the fungal community toward a phylogenetically impoverished, pathogen-dominated state. Specifically, exudates enriched the soil-borne pathogen Fusarium while reducing the abundance of potentially antagonistic fungi. In contrast, bacterial communities exhibited higher resilience, with exudates selectively enriching oligotrophic taxa such as Terrimonas and MND1, but suppressing nitrifying bacteria (e.g., Nitrospira) and plant-growth-promoting rhizobacteria (PGPR). Microbial functional profiling revealed a shift in nitrogen cycling, characterized by suppressed nitrification and enhanced nitrate reduction. Crucially, co-occurrence network analysis identified bacterial taxa strongly negatively correlated with Fusarium, providing a synthetic community blueprint for biocontrol strategies. Our study establishes a mechanistic link between root exudate accumulation and negative plant–soil feedback in monoculture systems, highlighting microbiome reprogramming as a key driver of replant disease. These insights offer novel avenues for manipulating rhizosphere microbiomes to sustain crop productivity in intensive agricultural systems. Full article