Apocynaceae is one of the ten largest families of angiosperms and a model system for studying pollination mutualism and coevolution between plants and animals. Their floral morphology are highly diverse, particularly in the Asclepiadoideae subfamily, which are well known for their specialized floral structures such as gynostegium, pollinaria, and stigmatic chamber. This article reviews the research progress of pollination ecology in Apocynaceae, including the diversity and adaptive significance of their floral structures, such as corolla, corona, and gynostegium; the diversity of sexual expression, including secondary pollen presentation, herkogamy, dioecy, and dichogamy; the diversity of pollinator animals, primarily consisting of Hymenoptera, Lepidoptera, and Diptera insects, with additional contributions from Blattodea (cockroaches); reproductive traits, such as low naturally fruit set, extremely low pollen-ovule ratios (P/O), and low self-compatibility; and chemical ecology, exemplified by the food-source and brood-site mimicry through floral scent emissions in the subtribe Stapeliinae of Asclepiadoideae, which deceive fly pollinators. Currently, the research of pollination on Apocynaceae in China remains limited, and habitat destruction has led to the extinction of many Apocynaceae species. Future studies should strengthen research on the pollination and chemical ecology of Apocynaceae to provide scientific basis for the conservation and sustainable utilization of these plants.

Maintaining xylem water transport is crucial for the growth and survival of vascular plants. Air bubbles entering the xylem form cavitation embolism, impairing the plant’s normal water transportation and leading to inhibited growth or even death. Accurately measuring a plant’s embolism resistance is fundamental to understanding species traits, adaptive mechanisms, distribution ranges, and serves as an effective approach for drought risk evaluation and forecasting of forest tree species. Currently, various methods are used to quantify xylem embolism, ranging from measuring water conductivity of plant organs to direct visualization of xylem embolism. These mainly include the evaporative flux method and rehydration kinetic method for leaves, the bench dehydration, centrifugation and pneumatron method for stems, the centrifugation and pressure chamber for roots, as well as techniques applicable to different plant organs such as X-ray microtomography and optical vulnerability technique (OV) applicable to different plant organs. Among these, OV-an emerging non-invasive technique enabling in situ measurement, with minimal constraints from plant size, low equipment cost, simple construction, and high result resolution—has attracted widespread attention and been extensively applied in various plant organs over the past decade. This review first summarizes the development history, working principle, and key operational points of the OV technique. Subsequently, based on an analysis of published literature data, it synthesizes the patterns of embolism formation and spread in different plant organs, explores the differences and variation characteristics of embolism resistance across plant organs, and elaborates on advances such as the relationship between xylem embolism and decreased hydraulic conductivity, as well as the association between embolism and stomatal closure. Finally, it summarizes the technical limitations based on current research practices and provides prospects for key issues that urgently need to be addressed in the future application of this technique in plant hydraulics.

Aims Temperature influences plant pollen morphology and physiological traits, thereby affecting sexual reproductive capacity. The invasive plant Spartina alterniflora, native to the North American Atlantic coast and Gulf of Mexico, has extensively colonized coastal intertidal zones and tidal flats across China, spanning approximately 20 degrees of latitude (19°-40° N). This broad geographic distribution makes it an ideal model for investigating temperature-driven variations in pollen traits. However, the relationships between S. alterniflora pollen morphology, viability, and their environmental drivers at a geographic scale remain poorly understood. Methods In this study, S. alterniflora pollen samples were collected across latitude in China. Using scanning electron microscopy and I₂–KI staining techniques, we characterized pollen morphology and viability. Integrate climate factors across different latitudinal zones during flowering periods for comprehensive analysis, aiming to investigate the geographical variation in S. alterniflora pollen morphology and viability, along with its primary driving factors. Important findings The results indicated that: (1) The shape of S. alterniflora pollen (polar axis length/equatorial axis length) showed no significant variation with latitude (R² = 0.003, p = 0.52 ), while pollen volume exhibited an S-shaped trend with increasing latitude (R² = 0.308, p < 0.001). (2) Pollen viability gradually increased with latitude, first decreasing, then increasing, and subsequently decreasing again (R² = 0.053, p = 0.007). (3) Temperature during flowering and humidity differentially influenced pollen traits: pollen shape was not significantly correlated with any of these factors. Pollen volume exhibited a parabolic quadratic relationship with temperature and humidity during flowering, but decreased with rising average temperature from June to September. Pollen viability decreased with increasing temperature but increased with humidity. (4) A random forest model identified average temperature from June to September as the primary factor affecting pollen shape variation, highest temperature of the day as the main driver of pollen volume variation, and daily relative humidity as the key factor influencing pollen viability. In summary, S. alterniflora pollen shape has not undergone adaptive changes under specific temperature environment, while pollen size and viability are more responsive to short-term temperature and humidity fluctuations. These suggest that the pollen morphology and viability of S. alterniflora differ in their latitudinal gradients adaptation strategies.

Aim This study aims to investigate the dynamics of spring canopy greenness in a subtropical evergreen broadleaf forest and to identify the key environmental factors influencing these changes. By focusing on the seasonal variations in greenness indices, this study attempt to demonstrate subtle seasonal transitions in subtropical forests contributing to the development of phenological models for such ecosystems. Methods The study was conducted in the Shimentai Forest Monitoring Station in Guangzhou, China, utilizing long-term observational data (2020–2023) from canopy phenology cameras. Greenness indices, including the Excess Green Index (ExG) and Green Chromatic Coordinate (GCC), were extracted from the images. These indices were combined with meteorological data from a flux tower. Analytical techniques such as random forest analysis, regression analysis, and Dynamic threshold method were applied to explore the variations in greenness indices during different phenological stages and their associated environmental drivers, including temperature, soil water content (SWC), relative humidity, and vapor pressure deficit. Important findings We found that: (1) The subtropical forest canopy in the Shimentai area of the Guangzhou region undergoes distinct spring leaf-coloring and leaf-unfolding periods, with canopy greenness remaining markedly lower from February through May; (2) the decline in greenness during the leaf-coloring period is jointly regulated by SWC, relative humidity, vapor-pressure deficit, and photosynthetically active radiation (PAR), whereas the greenness increase during the leaf-unfolding period is governed mainly by temperature; (3) when SWC drops below the critical 16 %–20 % range, the canopy becomes especially sensitive to leaf-coloring changes, providing a foundation for constructing phenological models for tropical forests.

Artificial grassland establishment is widely recognized as an effective strategy for restoring degraded grasslands; however, long-term successional processes often lead to vegetation-soil system disharmony and productivity decline. To clarify the coupling characteristics of vegetation and soil, as well as the underlying mechanisms driving vegetation diversity during restoration succession, this study investigated alpine artificial grasslands established for 3, 6, 11, and 17 years, with extremely degraded grassland and long-term fenced natural grassland as controls. Vegetation and soil attributes were systematically quantified, a comprehensive synergistic coupling evaluation system was constructed, and Bayesian modeling combined with structural equation modeling (SEM) was employed to identify key environmental drivers and disentangle their direct and indirect pathways influencing vegetation diversity. The results revealed that: (1) Aboveground biomass and litter biomass decreased progressively with increasing establishment age, while belowground biomass peaked at 6 years before declining. Shannon-Wiener diversity and species richness increased significantly over time; however, even 17-year-old artificial grasslands remained inferior to natural grasslands in terms of these diversity indices. Concurrently, soil quality (encompassing nutrient content and enzyme activity) improved substantially with prolonged establishment. (2) The synergistic coupling degree of the vegetation-soil system increased gradually but remained in a state of disharmony: 3-year-old grasslands exhibited serious disharmony with synchronous degradation of vegetation and soil; 6-11-year-old grasslands showed a transition from serious to moderate disharmony, characterized by soil lag; and 17-year-old grasslands advanced to moderate disharmony, still retaining soil-lag features. This indicates that delayed soil recovery is the primary bottleneck restricting the coordinated development of the ecosystem. (3) Soil organic matter and litter biomass emerged as the most critical drivers of vegetation diversity and richness. SOM enhanced diversity through both direct effects and indirect facilitation of soil nutrient availability, while litter biomass exerted significant negative direct effects on diversity, coupled with indirect regulation of soil nutrient cycling. In conclusion, alpine artificial grasslands failed to achieve the coordination level of natural grasslands even after 17 years of restoration, with soil system lag being the fundamental constraint on overall ecosystem synergy. Therefore, it is recommended to implement staged management strategies: during the early establishment stage (3-6 years), moderately removing litter to reduce its physical barrier effects and facilitate species colonization; during the middle to late establishment stages (6-17 years), strengthening soil organic matter supplementation and nutrient management to promote coordinated vegetation-soil system development and prevent secondary degradation.

Aims The alpine meadow ecosystem of the Qinghai-Tibet Plateau is highly sensitive to global change and human activities, with soil nutrient availability serving as a key factor regulating the structure and function of plant communities. Phosphorus (P), an essential element for plant growth, and silicon (Si), although non-essential, has the potential to enhance plant stress resistance and regulate nutrient absorption. However, their individual and interactive effects on the stability of alpine meadow communities remain unclear. Methods This study systematically investigated the effects of phosphorus, silicon, and their interaction on the structure, diversity, and stability of alpine meadow plant communities by conducting experiments on the eastern edge of the Qinghai-Tibet Plateau with different concentrations of phosphorus addition (Ca(H₂PO₄)₂, 40, 80, 120 g·m⁻², labeled as P1, P2, and P3, respectively), silicon addition (4 g·m-2 H4SiO4, labeled as Si), and combined phosphorus-silicon treatments (labeled as P1Si、P2Si、P3Si). Important findings Phosphorus addition significantly promoted the abundance and biomass of grass and sedge functional groups, but inhibited the abundance and biomass of forb species, leading to a significant decline in species richness and the Shannon-Wiener index. Silicon addition improved community evenness, asynchrony, and temporal stability. Compared with the same concentration of phosphorus addition alone, combined phosphorus and silicon addition partially alleviated the negative impact of phosphorus addition on community diversity, and their interaction was significant. Path analysis results indicated that phosphorus addition had a significant direct negative effect on community temporal stability. Silicon addition, conversely, showed a significant direct positive effect on community temporal stability. Regarding indirect pathways, phosphorus addition significantly reduced species diversity, and the decline in species diversity was significantly correlated with a decrease in community stability. Silicon addition significantly increased community evenness, and the enhancement of community evenness was significantly and positively correlated with increased stability. Therefore, silicon addition not only directly promoted stability but also produced beneficial indirect effects by enhancing community evenness. Thus, silicon plays a buffering role in maintaining species diversity, mitigating phosphorus-induced community structure simplification, and enhancing ecosystem stability and asynchrony. This study reveals the potential function of silicon in regulating the plant community structure and stability of alpine meadows, providing a theoretical basis for the ecological restoration and nutrient management of degraded meadows in this region.

Aims To reveal the spatial pattern and intraspecific association of Picea wilsonii population in the Datong River Basin of Qilian Mountains. Methods Based on a multiple replicate plot design, we used the paired correlation function g(r) and the bivariate paired correlation function g₁₂(r) within the framework of point pattern analysis to analyze the spatial distribution patterns and associations of individuals at different growth stages. Important findings (1) The static diameter distribution of the P. wilsonii population exhibited an inverse J-shaped, with young individuals accounting for 58.8% of the total, indicating a stable and growing population with good regeneration potential. (2) Young individuals exhibited a clustered distribution across all analyzed scales (0-25 m); middle-aged and adult individuals showed a clustered distribution at scales of 0-21 m and 0-6 m, respectively, and became randomly distributed at larger scales; old individuals displayed a random distribution across all scales. (3) Positive associations were observed between young and middle-aged individuals, and between young and adult individuals at scales of 2-25 m, suggesting a facilitative effect of large trees on young trees. Between middle-aged and adult individuals, no significant association was found at 0-6 m, but a positive association emerged at scales >6 m, with the strength of association gradually weakening as the size difference increased. No significant associations were detected between young and old individuals, nor between middle-aged and old individuals across all scales. A weak positive association was found between adult and old individuals at very short distances. Overall, the P. wilsonii population in the Datong River Basin of the Qilian Mountains exhibited a pattern of “clustered at small size classes, random at large size classes” and positive associations between saplings and medium/large trees, exhibiting clear scale dependence and developmental stage dependence.

【目的】蒙古扁桃（Prunus mongolica）为蒙古高原特有的孑遗物种，濒危，是蒙古高原戈壁荒漠群落的重要建群种，具有重要的观赏、生态和经济价值。为全面掌握蒙古扁桃种群生存现状，了解其种群结构、动态及其变化趋势，阐明种群更新与维持机制，【方法】针对我国境内蒙古扁桃的天然种群分布特征，本研究选取了4个典型生境（包括岩石荒漠、砾石戈壁、季节性河床、固定沙地）开展野外实地调查，依据大小级代替年龄级理论及匀滑技术，建立不同生境下种群的年龄结构和静态生命表，绘制存活曲线、死亡率和消失率曲线，结合种群的生存函数、数量动态及时间序列预测，对不同生境下蒙古扁桃种群的结构和动态趋势进行分析和预测。/t/n结果表明：①MQ、YM和AZ3个种群结构均呈现不规则的金字塔型，属增长型，种群生存曲线符合Deevey-Ⅱ型曲线，AY种群呈现中部膨大的纺锤形型，属衰退型，生存曲线趋于Deevey-Ⅲ型；②在随机性干扰下MQ、YM和AZ3个种群的增长趋势很小，一定时期内更趋于稳定状态；③ AY、YM、MQ和AZ4个种群分别在Ⅱ、Ⅲ、Ⅳ和Ⅴ龄级开始逐渐进入衰退期，相较其他种群，AY种群更早进入衰退期。在经历2、4和8个龄级后，MQ、YM和AZ3个种群未来仍呈增长趋势，AY种群仍属于衰退种群。/t/n研究认为，蒙古扁桃种群在幼龄株发育阶段均易受环境的影响，中龄株阶段表现出较强抗干扰能力，种群对环境波动有一定缓冲能力，具有较强的抗压韧性和自我调节能力。气候变化、强烈的人为干扰及其所导致的生境破碎化可能是造成种群濒危的主要原因，研究结果为蒙古扁桃的科学保护与利用提供理论依据，并为深入阐明其濒危机制奠定了基础。

Aims The survival and growth of woody plant seedlings are regulated by a complex interplay of multiple environmental factors. However, how the forest canopy regulates understory herbaceous cover and microclimate to subsequently influence seedling survival and growth remains poorly understood. Methods This study investigated seedlings of three dominant species, Malus sieversii, Juglans regia, and Prunus armeniaca, in wild fruit forests in the Tianshan Mountains through five consecutive years of field surveys and microclimate monitoring. Important findings Our results show that canopy cover indirectly influenced the survival of seedlings of the three wild fruit tree species by regulating understory microclimate and herbaceous cover. Among these factors, herbaceous cover was an important determinant of seedling survival,existing negative effects on seedlings of M. sieversii and P. armeniaca, while demonstrating a positive effect on seedlings of J. regia. In terms of seedling growth, the key limiting factors differed among species. The growth of seedlings of M. sieversii was mainly affected by soil pH and herbaceous cover; the growth of seedlings of J. regia was primarily associated with herbaceous cover and mean temperature of the growing season; whereas the growth of seedlings of P. armeniaca was mainly constrained by mean temperature of the growing season. In conclusion, canopy cover regulates the survival and growth of wild fruit tree seedlings through multiple direct and indirect pathways, and the responses of seedlings of different tree species to biotic and abiotic factors differ significantly. The conservation and restoration of wild fruit forests should fully consider the differential responses of seedlings for different tree species to environmental factors and adopt targeted habitat management measures in the Tianshan Mountains.

Aims The environments of northern tropical karst peak-cluster region are characterized as thin soil and extensive rock outcrops. In the hot summer, the rocks can heat the surrounding air. Karst plants not only endure water and nutrient stress, but also experience high-temperature stress. Previous studies have investigated the environmental adaptation of karst woody plants in terms of hydraulics and nutrient stoichiometry, but their heat tolerance remains poorly understood. Therefore, this study aims to reveal the photosynthetic heat tolerance of woody plants from the northern tropical karst seasonal forest and its differences from other tropical-subtropical forest species, and explore the relationships between heat tolerance and leaf functional traits in tropical karst species. Methods In this study, we selected 20 typical woody plant species from a northern tropical karst seasonal rainforest in southwestern Guangxi. The temperature at which the maximum photochemical efficiency of photosystem II decreases by 50% (T50), critical temperature (Tcrit), thermal sensitivity (ΔT), hydraulic traits, morphological and anatomical traits, and stoichiometric characteristics were measured. Important findings The results showed that: (1) the average T50, Tcrit, and ΔT for the studied tropical karst species were 50.7℃, 43.8℃, and 6.9℃, respectively. Compared to woody species from tropical ravine rainforest, dry-hot valley, and southern subtropical seasonal evergreen broad-leaved forest in China, the woody plants in the northern tropical karst region exhibit lower photosystem heat tolerance. (2) T50 were positively correlated with leaf mass per area, leaf thickness and upper epidermis thickness, indicating that species with higher leaf construction costs and thicker leaf tissues demonstrated greater heat tolerance. (3) T50 was negatively correlated with N, P and K concentrations, indicating that species tolerant to nutrient-poor conditions had stronger heat tolerance. However, T50 was not correlated with Ca, Mg, N:P, and Ca:Mg. (4) There were no significant correlations between T50 and turgor loss point and cavitation resistance, indicating that drought tolerance was decoupled from heat tolerance. Given the climate in the northern tropical China is becoming drier and hotter, a comprehensive understanding of the heat tolerance of karst plants is of great significance for plant diversity conservation and vegetation restoration.

Aim：Revealing the regional differentiation patterns of functional traits and adaptation strategies of native spontaneous herbs in riparian zones is of great significance for predicting their survival and adaptation potential under the disturbance of urbanization. Methods：In this study, we took the riparian spontaneous herb Persicaria maculosa as the research object, to analyze the adaptation mechanism of functional traits of its leaves and fine roots to urbanized degraded soils. We set up 72 sampling plots in the riparian zone of the Fuzhou section in the lower reaches of the Min River, measured 22 phenotypic functional traits, and combined them with soil physicochemical indicators including soil bulk density, water content and salinity. Methods such as variance analysis, trait network analysis, principal component analysis (PCA) and linear mixed-effects model (LMM) were adopted to reveal the response pattern of aboveground and belowground organs of P. maculosa to urbanization-induced soil gradients. Important findings：The results show that the leaves and fine roots of P. maculosa did not respond synchronously to urbanized soil. Leaves adopted an overall conservative strategy, reducing resource consumption solely by decreasing leaf area. In contrast, fine roots were more sensitive to soil degradation, with significant declines in root length and water content. In multidimensional trait space, the resource-use strategy of P. maculosa shifted from acquisitive to conservative. Specifically, leaves transitioned from a rapid acquisition mode characterized by high resource turnover to a conservative maintenance strategy centered on dry matter accumulation; fine roots shifted from a resource-expansion strategy relying on high specific root length to a conservative strategy that emphasizes increased tissue density and enhanced structural stability. Soil degradation disrupted cross-organ coordination, driving the plant phenotypic network from whole-plant integration toward modular decoupling between leaves and fine roots. The multiple stresses of urbanized soil weakened the regulatory coordination between aboveground and belowground organs, constrained phenotypic plasticity, and pushed the plant’s response to soil environmental variation toward a more conservative and stable state. This study reveals the conservative adaptive strategy of a native herbaceous species to urban degraded soils, offering theoretical insights and practical guidance for the ecological restoration of urban riparian zones.

Aims Functional traits are widely used to predict plant performance, including growth. However, many empirical studies have shown that the predictive power of traits for growth is often weak. One possible explanation is that trait-growth relationships are not fixed, but depend on the abiotic and biotic contexts in which plants grow. This study tested whether seedling trait-growth relationships depend jointly on abiotic environmental gradients and interspecific competition. Methods We conducted a two-year greenhouse experiment from 2019 to 2021 in Tiantong Mountain, Ningbo, Zhejiang Province, China. We grew 2520 seedlings of seven common woody species under experimentally manipulated gradients of light intensity, soil moisture, and soil available phosphorus, with and without interspecific competition. Seedling height was measured during the experiment, and eight above- and belowground functional traits were quantified. We evaluated the environmental dependence of trait-growth relationships using both individual traits and multidimensional trait axes. Important findings Trait-growth relationships were jointly regulated by abiotic environments and interspecific competition. Variance decomposition showed that, regardless of whether individual traits or multidimensional trait axes were used, interspecific competition explained a larger proportion of variation in seedling growth (18.9%) than abiotic environments (8.8%) and traits themselves (1.4%). This indicates that the competitive environment was a major determinant of seedling growth variation and trait effects in this experiment.The relationship between aboveground trait axes and growth mainly varied along the light gradient, whereas the relationship between belowground trait axes and growth was mainly regulated by soil available phosphorus. Some trait-growth relationships showed directional reversals across environmental gradients. Interspecific competition further altered how traits affected growth: the relationships of aboveground PC1 and PC2 with growth both reversed between no-competition and competition conditions. These findings indicate that trait–growth relationships in tree seedlings are strongly context dependent, with both abiotic resource gradients and competitive environments determining the direction and strength of trait effects. Incorporating multilevel environmental contexts into trait-based frameworks may help explain the weak predictive power of trait-growth relationships and improve trait-based predictions of forest regeneration and community dynamics.

Aims Davidia involucrata Baill. is a nationally protected plant. This study investigates the functional trait differences and growth strategies of the leaves, stems, and roots at different life history stages of D. involucrata, providing scientific basis for the conservation and restoration of rare and endangered plants. Methods This study focuses on seedlings, saplings, and adult trees of D. involucrata cultivated in Yantai. Functional traits of leaves, stems, and roots were analyzed to explore the differences in these traits across different life stages, as well as the key growth strategies of each organ and their impact on overall growth. Important findings (1) Leaves, stems, and roots exhibited an "acquisitive strategy" at the seedling and sapling stages but shifted to a "conservative strategy" at the adult stage. From the seedling to adult stage, leaf chemical element concentrations decreased and leaf morphology became thicker and denser, indicating a transition from rapid growth to a stable strategy emphasizing structural reinforcement and defense. Stem dry matter content and wood density increased while chemical element concentrations declined, indicating a shift from rapid growth to enhanced structural strength and mechanical support. Specific root length, root dry matter content, and vessel density increased, with roots transitioning from rapid proliferation to a strategy characterized by structural stability and strengthened defense. (2) At the seedling stage, leaves, stems, roots, and the whole plant displayed a "P-use strategy", characterized by relatively high P concentration, C:N ratio, and specific root length, with resources preferentially allocated to the construction of fundamental biological structures and rapid expansion of organs to facilitate efficient resource acquisition. At the sapling stage, an "N-use strategy" predominated, with higher N concentration and N:P ratio, indicating increased investment in nitrogen for the synthesis of proteins, nucleic acids, and chlorophyll to enhance photosynthetic capacity and support rapid growth. At the adult stage, roots exhibited a "P-use strategy", whereas leaves, stems, and the whole plant reached a relative balance in N-P nutrient utilization. (3) The resource investment and structural construction strategies of the stem, root, and whole plant exhibit significant synergy during the seedling stage. The resource investment and structural construction strategies of the root and whole plant exhibit significant synergy during the sapling stage. The nutrient-use strategies of the stem and whole plant exhibit significant synergy during the adult stage. The results provided a scientific basis for the conservation practices of translocated D. involucrata.

Aims Pressure–volume (PV) curves are widely used to characterize leaf water relations, yet the turgor-decline segment (D2) is often treated as a single linear and reversible process, potentially overlooking a transition from elastic to elastoplastic behavior. We aimed to (i) identify the yield point (P_y) via segmented fitting as a physiological marker of this transition, and (ii) test how P_y and the turgor loss point (Ψ_tlp) bound the upper limit of rehydration capacity, thereby evaluating their drought relevance. Methods Leaves of Platanus occidentalis (isohydric-leaning) and Fraxinus chinensis (anisohydric-leaning) were measured. P_y was identified by continuous segmented fitting of PV data. After the first PV run, the same leaves were rehydrated in darkness for ~30 h to obtain the maximum fresh mass, which was compared with fresh-mass estimates back-calculated at P_y and Ψ_tlp. Species differences in Ψ_sat, Ψ_tlp, and P_y were analyzed. Important findings The maximum fresh mass consistently fell between estimates at P_y and Ψ_tlp; it reached 92.6% ± 5.0% (P. occidentalis) and 86.4% ± 3.5% (F. chinensis) relative to P_y, and 109% ± 4.0% and 99% ± 4.0% relative to Ψ_tlp. Ψ_sat and Ψ_tlp differed significantly between species (higher in the isohydric species), whereas P_y did not. Interspecific differences were captured by the position of the rehydrated maximum within the (P_y, Ψ_tlp) interval rather than by the absolute values of P_y or Ψ_tlp. These results indicate that P_y marks the mechanical transition of cell walls, and that P_y together with Ψ_tlp bounds rehydration capacity in detached leaves; the rehydration window (P_y–Ψ_tlp) and its position metric hold promise as diagnostic indicators of drought tolerance.

Our results indicate that adventitious root formation is accompanied by profound metabolic reprogramming, leading to the identification of 229 significantly differential metabolites, primarily including flavonoids, phenolics, terpenoids, and plant hormones. The RSN exhibited a "growth-oriented" metabolic profile, characterized by the significant activation of pathways such as phenylpropanoid biosynthesis, the pentose phosphate pathway, and tyrosine metabolism. Metabolites including ribulose-5-phosphate, jasmonic acid, indole-3-butyric acid, catechin, and arctigenin were significantly upregulated, collaboratively promoting cell division, energy supply, antioxidant defense, and cell wall lignification to drive rapid rooting and tissue regeneration. In contrast, the NRSN shifted to a "survival-oriented" metabolic state by accumulating inhibitory substances such as trans-cinnamic acid, skimmin, ursolic acid, and the inactive auxin indole-3-acetylaspartic acid. This enhances its allelochemical defense and stress resistance, thereby suppressing its own growth to adapt to unfavorable conditions. This study reveals that Alternanthera philoxeroides stem nodes can dynamically switch between "growth" and "defense" modes. This high degree of metabolic plasticity represents a core molecular mechanism for its successful adaptation to heterogeneous aquatic-terrestrial environments and its efficient invasive expansion. Our findings not only deepen the molecular understanding of the ecological adaptation strategies of clonal plants but also provide a novel theoretical basis for developing green control technologies for invasive plants by targeting specific metabolic pathways.

Aims Soil microorganisms play a crucial role in forest succession and the maintenance of soil functions. Forest fires directly or indirectly affect soil, vegetation, and microbial activity through high temperatures, thereby influencing soil multifunctionality. However, current research on the effects of fire disturbance on rhizosphere and bulk soil bacterial community characteristics and soil multifunctionality remains limited. Methods This study investigated the rhizosphere and bulk soil of Larix gmelinii in Daxing'an Mountains three years after fire, using 16S rRNA high-throughput sequencing to analyze bacterial community characteristics and measuring indicators characterizing soil nutrient cycling to quantify soil multifunctionality. The research aimed to explore the effects of fire disturbance on bacterial community diversity, composition, and soil multifunctionality in rhizosphere and bulk soil, revealing the driving mechanisms of soil multifunctionality. Important findings Results indicate that fire significantly altered the structure of the rhizosphere bacterial community and reduced species richness. Before and after burning, dominant bacterial phyla in both rhizosphere and bulk soil of Larix gmelinii remained similar but differed in relative abundance. Fire disturbance markedly reduced soil multifunctionality, with rhizosphere soil and bulk soil decreased by 164 % and 260 %, respectively, and post-fire rhizosphere soil multifunctionality significantly higher than in bulk soil. Partial least squares structural equation modeling (PLS-PM) revealed that fire disturbance exerts not only a significant negative direct effect on soil multifunctionality but also regulates bacterial community composition by altering soil pH, thereby imposing an indirect negative impact on soil multifunctionality. Concurrently, rhizosphere and bulk soils indirectly affect soil multifunctionality by driving differences in bacterial community structure. Fire disturbance and bacterial community composition are key regulatory factors of soil multifunctionality. This study reveals the critical driving mechanisms of forest fires on soil multifunctionality, providing theoretical foundations for deepening our understanding of forest ecosystem responses to fire disturbance.

Aims Long-term monoculture often leads to soil degradation and reduced productivity, threatening agricultural sustainability. To explore a more sustainable cropping system, this study investigated intercropping alfalfa within apricot orchards, focusing on its effects on soil microbial communities, soil physicochemical properties, and crop yield. It aimed to clarify the role of different alfalfa row spacing configurations in this system, providing a basis for developing sustainable agricultural models that synergize ecology and production in arid and semi-arid regions. Methods Five treatments were set up: monoculture apricot (X), monoculture alfalfa with 20 cm row spacing (A), monoculture alfalfa with 30 cm row spacing (B), apricot intercropped with 20 cm alfalfa spacing (JA), and apricot intercropped with 30 cm alfalfa spacing (JB). High-throughput sequencing was used to analyze changes in soil bacterial and fungal diversity and abundance. Crop yield and land use efficiency were comprehensively compared. Important findings Compared with monoculture, intercropping altered soil microbial composition, increasing the proportion of beneficial microorganisms such as Bacillus, and enhanced microbial functions related to nutrient cycling and energy metabolism. The intercropping pattern with 30 cm alfalfa row spacing performed better in maintaining microbial community stability. Soil organic matter and nitrogen content increased over years under intercropping, while soil salt accumulation was reduced. Monoculture apricot was less effective in maintaining soil fertility and controlling salinity. Although the individual yields of apricot and alfalfa in intercropping were lower than their respective monocultures, both intercropping patterns demonstrated higher land use efficiency (Land Equivalent Ratio > 1). The intercropping pattern with 30 cm alfalfa row spacing better alleviated interspecific competition for resources. In conclusion, apricot-alfalfa intercropping is a cropping model that balances ecological benefits (improving soil quality, optimizing microbial community) and production efficiency (enhancing land use efficiency). Rational adjustment of alfalfa row spacing (30 cm) can further optimize system function. This model is suitable for promotion in arid and semi-arid areas like Xinjiang, offering practical references for local sustainable agricultural development.

The Qinghai-Tibet Plateau is an important ecological security barrier in China. Its herbaceous vegetation is widely distributed, exhibits diverse alliance types, and provides essential ecological functions. Owing to the complexity of its physical geographic environment, previous vegetation surveys still left many gaps; moreover, in recent years, human activities and climate change have also caused substantial changes in the vegetation of this region. Therefore, the baseline data on herbaceous vegetation across the Plateau require urgent updating. Based on vegetation survey data from the Second Tibetan Plateau Scientific Expedition and Research Program, and through comparison with existing vegetation monographs and related literature, this study systematically identified 75 newly recorded alliance types of herbaceous vegetation on the Qinghai-Tibet Plateau. Their habitat characteristics and community features are described, together with representative plot data and community photographs. These newly recorded alliance types belong to five vegetation formations and 17 vegetation subformations. Forb grasslands were the most abundant (50), most of which are concentrated in the alpine forb meadow subformation (33). This study supplements and improves the classification system of herbaceous vegetation on the Qinghai-Tibet Plateau, fills gaps in alliance-level surveys for local areas and special habitats, and provides fundamental data for research on grassland ecosystems and biodiversity conservation.