Aims Interspecific competition is a key process regulating plant community assembly and productivity, and nitrogen and phosphorus availability are major factors influencing interspecific competitive interactions among wetland plants. However, systematic understanding of the differences between aboveground and belowground competition, especially under nitrogen and phosphorus enrichment conditions, remains limited, hindering predictions of wetland community dynamics. Methods We conducted a greenhouse experiment with two plant species, coexisting and habitat-similar dominant perennial species in the Poyang Lake, Carex cinerascens and Phalaris arundinacea. Experimental treatments included four competition treatments (no competition, aboveground competition [AGC], belowground competition [BGC], and both competition) and four nutrient conditions (control, nitrogen addition [N], phosphorus addition [P], and combined nitrogen–phosphorus addition [NP]). Aboveground and belowground biomass of both species were measured under each treatment to evaluate biomass allocation strategies. Relative interaction index (RII) under different nutrient conditions were calculated to assess the effects of nutrient inputs on interspecific competition. Important findings 1) BGC was the primary driver of growth and biomass allocation, with C. cinerascens showing a strong BGC advantage and maintained overall dominance by allocating more biomass to aboveground parts, whereas P. arundinacea was suppressed by BGC and allocated more biomass to belowground parts to alleviate this suppression; 2) N addition reduced the BGC advantage of C. cinerascens, P addition alleviated the suppressive effects of BGC to P. arundinacea, and NP addition enhanced its competitive advantage while reducing inhibition of P. arundinacea, resulting in increased total biomass; 3) The effects of nutrient inputs on interspecific competition were primarily driven by interactive effects of AGC and P addition on belowground biomass, and by interactive effects of BGC and N addition on aboveground biomass. Conclusions Nutrient addition can alter interspecific competitive relationships between plant species, but only synchronous changes in nitrogen and phosphorus availability can enhance total biomass while maintaining table biomass proportions between the two species . Therefore, under future nutrient-enrichment scenarios, coordinated regulation of nitrogen and phosphorus is critical for sustaining productivity and diversity in wetland plant communities.

Aims Microplastic pollution and multispecies invasions are escalating global threats to native plant communities. However, how plant communities respond to microplastics in the context of multispecies invasions, and the mechanisms driving these responses, are still largely unknown. To address this gap, we conducted a controlled experiment. Methods We established synthetic plant communities composed of three grass species, three legume species, and three invasive species along a 12-level abundance gradient of polypropylene microplastics. To elucidate the underlying ecological drivers, we measured soil physicochemical properties, community-level fluorescence traits, species richness, community biomass, and species relative abundance. Furthermore, structural equation modeling was used to identify key pathways. Important findings (1) Overall, polypropylene (PP) microplastics significantly decreased plant species richness, especially at intermediate levels, without a consistent monotonic trend. (2) Unlike plant species richness, PP microplastics did not decrease overall community biomass, and community biomass exhibited a U-shaped response, decreasing at low to medium microplastic levels and increasing significantly at high levels. (3) PP microplastics had no significant effect on the relative abundance of invasive plants, but significantly affected community-level fluorescence traits, and soil phosphorus and potassium. Structural equation modeling revealed distinct pathways by which microplastics influenced plant species richness, invader relative abundance, and community productivity. These findings suggest that microplastics could regulate plant diversity and community productivity primarily by altering soil nutrient availability and plant functional traits. Furthermore, soil nutrients and pH could exert contrasting influences on invasion processes under microplastic stress.

Aims Environmental gradients and human disturbance are key drivers affecting soil microbial communities and biodiversity, yet their combined effects on soil legacy processes and subsequent plant growth remain poorly understood. Methods We conducted a study in the Shennongjia region of Hubei Province, China. Plots characterized by three disturbance levels—Low, Medium, and High disturbance—were established along an elevational gradient ranging from 500 to 3000 m. By combining field sampling with a greenhouse common garden experiment, we systematically evaluated the impacts of elevational gradients and human disturbance on soil microbial communities and the resulting soil legacy effects on plant growth. Important findings Elevation significantly reduced the α-diversity of soil bacteria and fungi and markedly altered microbial community composition, whereas the direct effects of human disturbance on microbial community structure were relatively weak. Soil legacy effects varied significantly across human disturbance levels, with medium disturbance markedly amplifying the positive effects of soil legacies on plant total biomass, while these effects weakened or became neutral under low and high disturbance conditions. The legacy effects on the root-to-shoot ratio showed a significant interaction between elevation and disturbance, indicating that the response of plant resource allocation strategies to soil historical conditions is strongly environmentally dependent. Structural Equation Modeling (SEM) further revealed that elevation indirectly influenced plant traits primarily through its effects on fungal communities, while interactions between fungal and bacterial communities regulated the direction and magnitude of soil legacy effects. Overall, soil legacy effects serve as a key mechanism linking elevational gradients, human disturbance, and plant growth responses, with their ecological importance being particularly pronounced under medium disturbance conditions. This study highlights the necessity of incorporating soil legacy effects when predicting subtropical mountain vegetation dynamics in the context of global change.

The soil seed bank, as a "storage" of aboveground vegetation species diversity, is the material foundation for plant community renewal and succession and a core driving force for regional vegetation natural restoration. This review, based on recently published high-impact studies, systematically summarizes the dynamic characteristics and driving mechanisms of soil seed banks in community succession, the impact pathways of disturbances on seed banks, and the application potential and limitations of seed banks in ecological restoration.The study found that the seed bank density, species richness, and composition show regular changes across succession stages, with high seed density in early stages, high richness in mid-stages, and low similarity in late stages as cross-system common characteristics; Disturbances affect seed bank functions through direct (e.g., climate change, physical disturbances), indirect (e.g., habitat changes, intensified competition), and cross-scale pathways (e.g., temporal mismatches, spatial diffusion), with multi-path interactions leading to nonlinear responses; Although seed banks provide a source of seed for the restoration of degraded ecosystems, their application is limited by the availability of target species seeds and environmental stress. Future research should focus on strengthening long-term monitoring, analyzing multi-factor interaction mechanisms, and developing precise restoration technologies based on seed bank characteristics to address ecological restoration challenges under global change.

Aims Large-scale Chinese fir (Cunninghamia lanceolata) plantation management has caused severe forest nutrient imbalance in subtropical regions. Transforming stands by increasing tree species diversity is an important approach to mitigate nutrient imbalance in Chinese fir plantations. However, the effects of neighbourhood tree species richness on litter nutrient concentrations and their stoichiometric characteristics remain unclear. Methods This study established gradients of neighbourhood tree species richness (1, 4, 6, 7, and 8 species) to investigate their effects on the concentrations of carbon (C), nitrogen (N), and phosphorus (P) and the stoichiometric characteristics of Chinese fir litter in subtropical plantations. Important findings The results showed that litter N and P concentrations increased by 37.1% and 45.9% at richness levels of 6 and 7 species, respectively, compared with the monoculture treatment. This increase resulted in significant reductions in litter C/N and C/P, by 26.9% and 31.5%, respectively. Soil nitrate nitrogen was positively correlated with litter N concentration and negatively with litter C/N. Soil available phosphorus was significantly positively correlated with litter P concentration, resulting in a significant negative correlation with litter C/P. The best-fitting linear mixed-effects models showed that soil available phosphorus and pH were the main factors explaining variation in litter P concentration and C/P. Therefore, these findings suggest that a moderate increase in neighbourhood tree species richness enhances litter nutrient concentrations in the target tree species and reduces its carbon-to-nutrient stoichiometric ratios, thereby promoting litter nutrient return and improving forest nutrient status in Chinese fir plantations.

Abstract Aims The stoichiometriy of plant leaves, twigs, and fine roots are key indicators for characterizing whole-plant adaptive strategies and for revealing the mechanisms underlying plant-environment interactions. Investigating the interrelationships among leaf-twig-root stoichiometriy in desert plants, as well as their differences in environmental adaptability, is essential for advancing our understanding of plant resource allocation strategies. Methods In this study, we selected 20 desert plant species from the Baijitan region of Ningxia and measured the concentrations of carbon (C), nitrogen (N), phosphorus (P), potassium (K), calcium (Ca), and magnesium (Mg) in the leaves, twigs, and fine roots of 77 individuals. Important findings (1) Leaf C concentrations were significantly lower than those in twigs and fine roots, whereas the N, P, K, Ca, and Mg concentrations of twigs and fine roots were significantly lower than those of leaves. (2) Network analysis showed that the overall network parameters—edge density, average path length, diameter, average clustering coefficient, and modularity—were 0.40, 1.75, 4, 0.59, and 0.11, respectively; a total of 54 element-element pairs exhibited significant correlations. (3) Leaf K concentration and twigs C concentration exhibited the highest degree and closeness centrality, identifying them as hub elements within the network. Twigs showed the highest element degree, indicating that they function as the key hub organ. (4) Variance partitioning revealed that soil pH, total C, and total P had the strongest effects on the stoichiometry of leaves, twigs, and fine roots, respectively; soil total N had the greatest influence on leaf and twigs N concentrations, whereas soil pH most strongly affected fine-root C concentration. This study systematically uncovers the element coordination network among leaves, twigs, and roots of desert plants in the Baijitan region and elucidates their response mechanisms to soil environmental factors, providing new theoretical support for understanding desert plant ecological adaptation from a multi-element perspective. Our findings further highlight the need to incorporate key elements such as K, Ca, and Mg when examining plant stoichiometry, in order to more comprehensively reveal the coordinated regulation of C, N, P, K, Ca, and Mg across different organs and their roles in environmental adaptation.

Aims The response of forest soil organic carbon (SOC) to global change has remained a prominent frontier issue in ecological research. Although numerous studies have demonstrated that nitrogen deposition can promote the accumulation and of forest SOC and enhance its stability, the impact of nitrogen deposition on the accumulation process of specific plant-derived components in SOC, such as lignin phenols, remains unclear. This knowledge gap limits our in-depth understanding of forest carbon cycling processes and their pivotal role in maintaining global carbon balance. Methods Based on the long-term (more than 20 years) nitrogen deposition experimental platform in Dinghu Mountain（112° 10′ E, 23° 10′ N）, this study systematically investigated the effects of long term nitrogen addition on the accumulation patterns of lignin phenols across different soil layers and their underlying mechanisms. Important findings The results indicated that: (1) Lignin phenol content significantly decreases with soil depth; Nitrogen addition increased lignin phenol content by 23.7% in the 0-10 cm soil layer but had no significant effect on the 10-30 cm layer. (2) Under the control treatment, the activity of C-degrading enzymes is a key factor influencing lignin phenol accumulation; Nitrogen addition inhibited C-degrading enzyme activityand weakened their regulatory effect on the accumulation of lignin phenols. However, lignin phenols were more effectively protected through physical and chemical binding with soil minerals, thereby significantly reducing their bioavailability. In summary, the impact of long-term nitrogen deposition on plant-derived carbon in tropical forests exhibits significant soil layer dependency, with its effects limited to promoting lignin phenol accumulation in the surface soil layer. long term high nitrogen input has altered the regulatory pathways of plant-derived carbon accumulation in tropical evergreen broadleaf forest soils, shifting from microbial degradation processes to physicochemical protection as the dominant mechanism. This study unveils a novel mechanism for maintaining the stability of tropical forest soil carbon pools under nitrogen deposition, providing crucial theoretical insights for predicting forest soil carbon dynamics.

Aims The biodiversity-ecosystem function relationship is a prominent research topic within ecology. In the context of global environmental changes, biodiversity loss may constrain ecosystem functioning. Most existing studies focus on diversity effects on individual functions (e.g., productivity, carbon sequestration, etc.) or ecosystem multi-functionality (EMF), while overlooking the interactions among different ecological functions - a phenomenon quantified as ecosystem coupling. To date, it remains elusive how diversity changes impact ecosystem coupling and the relationships between EMF and ecosystem coupling. Methods Using standardized field surveys across 40 sampling sites across the Tibetan alpine grasslands, we explored the large-scale patterns of ecosystem multifunctionality and ecosystem coupling, and their relationships with plant diversity. Important findings The EMF exhibited highly spatial heterogeneity, while ecosystem coupling showed less variation at the regional scale. Meanwhile, no significant correlation was observed between EMF and ecosystem coupling. The EMF was significantly correlated with climatic factors, plant diversity, and soil properties, whereas ecosystem coupling remained insensitive to variations in both biotic and abiotic drivers. These results reveal a widespread decoupling between EMF and ecosystem coupling at the large scale, not supporting the notion that higher EMF associated with stronger ecosystem coupling based on controlled experiments. Our findings provide new insights into the relationship between biodiversity and ecosystem functions, and also lay a theoretical base for achieving the national strategy of "integrated management of mountains, waters, forests, farmlands, lakes, grasslands and deserts " via biodiversity conservation.

Xiaowutai Mountain, located at the junction of the Taihang, Yanshan, and Hengshan ranges, represents a typical temperate montane forest ecosystem in North China and serves as an important ecological barrier for the Beijing–Tianjin–Hebei region. To fill the gap in systematic vegetation survey data, we conducted a plot-based survey during the 2025 growing season following unified technical protocols. A total of 67 plots were established along an elevation gradient and across different slope aspects to record community structure, species composition, and environmental variables; vegetation types were then classified and named, and the records were integrated into a vegetation plot dataset for the Xiaowutai National Nature Reserve. We documented 321 vascular plant species belonging to 197 genera and 69 families, with Asteraceae, Rosaceae, and Poaceae as the dominant families. By life form, there were 225 herbs (70.1%), 58 shrubs (18.1%), 23 trees (7.2%), and 7 species of ferns and lianas combined (2.2%), plus a single subshrub species. The vegetation was categorized into three vegetation formation groups, seven vegetation formations, and 36 associations, which together essentially cover the spatial distribution range of the major vegetation types in Xiaowutai Mountain. This dataset provides reusable baseline information for vegetation classification, community comparisons, and conservation zoning in Xiaowutai Mountain.

Aims To clarify how water use in rubber plantations (Hevea brasiliensis) varies across leaf phenophases and to identify the key environmental drivers of stem sap flow dynamics, thereby improving assessment of impacts on regional water cycling and informing water-resource management. Methods We continuously monitored stem sap-flux density (Fd) with the thermal dissipation probe (TDP) method across four phenophases—defoliation, early leaf-expansion, mid leaf-expansion, and late leaf-expansion. Environmental variables (soil and atmospheric temperature and humidity, etc.) were recorded synchronously. We then applied XGBoost coupled with the SHAP interpretability framework to quantify the relative contributions of candidate drivers. Important findings (1) Phenology strongly modulates water use: Fd and tree-level water use differed significantly among phenophases (p < 0.05), in the order of late leaf-expansion > mid leaf-expansion > defoliation > early leaf-expansion; the daily mean Fd in late leaf-expansion was 4.4–6.1 times that of the leafless periods (defoliation and early leaf-expansion), indicating a significant increase in water consumption (p < 0.05). (2) The dominant environmental drivers shift with phenology. During defoliation, air temperature (Ta; 32.39%) and volumetric soil water content at 5 cm depth (VWC₅; 24.38%) were the primary drivers. In the early leaf-expansion, soil temperature (Ts; 36.61%) and photosynthetically active radiation (PAR; 19.55%) prevailed. During mid leaf-expansion, vapor pressure deficit (VPD; 52.16%) dominated. In late leaf-expansion, Ta again was the key driver (62.75%). Mechanistically, leaf phenology modifies canopy leaf area (and thus canopy conductance), reshaping the soil–plant–atmosphere water-potential gradient, so that limitation of water use shifts from soil water availability and temperature toward atmospheric evaporative demand; this shift amplifies phenophase-dependent differences in sap flux and water consumption. These results delineate the phenology‐dependent dynamics and driver transitions of sap flow in H. brasiliensis, and provide an evidence base for water resource management and strategy development in tropical plantations.

Aims Leaves, exhibiting the highest ecological plasticity, are the most sensitive to environmental change. It also acts as the hydraulic bottleneck and safety valve against hydraulic dysfunctions. Populus euphratica Oliv. is well-adapted to extreme arid environments and possess heteromorphic leaves distributing differentially along tree vertical heights. Exploring the pattern variations of hydraulic and anatomical traits of heteromorphic leaves and their interaction, and underpinning mechanisms of morphological divergence along groundwater depth(GWD) and vertical heights is better understanding their adaptation strategies to adverse environment, so as to provide a scientific basis for protection and restoration of desert P. euphratica forest under global change. Methods Through community investigation along GWD, we measured the hydraulic, structural and morphological traits in three different leaf shapes of adult P. euphratica trees along canopy vertical height. The differences between hydraulic traits (e.g., Hydraulic conductance, vein, stomata), anatomical structures and morphological traits of heteromorphic leaves and their interrelationships were examined. Important findings (1) Under different GWD conditions, significant differences were observed in the morphological, hydraulic and anatomical traits of leaves with the same morphology, while under the same GWD, three heteromorphic leaves exhibited notable variations in these traits across different canopy heights. For the same leaf shape, the minor vein density, loopiness of veins, free-end density, conduit density, leaf thickness, palisade-to-spongy mesophyll ratio, epidermal and cuticular thickness increased with rising GWD, while these traits increased along vertical canopy height under the same GWD. Deeper GWD and higher canopy positions were associated with enhanced vein development and more xeromorphic anatomical structures in heteromorphic leaves. (2) Compared to the heteromorphic leaves in the lower-middle canopy, the serrated broad-oval leaves in the upper canopy are wider and thicker, with more developed palisade tissue and complex venation networks. These structural adaptations have evolved to cope with strong light, high temperature and increased transpiration demands, resulting in a more efficient hydraulic system and strongly defensive architecture, enhancing the water transport efficiency and water retention capacity, thereby improving embolism resistance and drought tolerance. (3) The leaf length-width ratio (LI) and dissection index (DI) were significantly correlated with most hydraulic and anatomical traits. Hydraulic traits contributed more to leaf morphological variation than anatomical features, with interval between veins, closed loop area, vein density, proportion of minor veins, as well as palisade-spongy ratio, epidermal and cuticular thickness playing predominant roles in shaping leaf morphology. (4) Most leaf morphological traits showed a highly significant correlation with hydraulic path length and leaf attachment height. Hydraulic path length mediates leaf morphological variation (LI, DI) by influencing hydraulic and anatomical structures, indicating that hydraulic constraints along vertical gradient are a key factor driving leaf morphological differentiation in P. euphratica. (5) The coupling between hydraulic traits and anatomical structures contributes to improve hydraulic functionality and enhanced stress resilience in P. euphratica. Leaf morphological differentiation represents an ecological strategy evolved by the species to adapt contrasting hydraulic environments throughout its life cycle.

Aims Climate change has led to a marked increase in the frequency of extreme heat events, posing a serious threat to wheat growth. Existing studies have investigated the effects of extreme heat on the photosynthetic processes of wheat, whereas studies on its effects on leaf temperature and the underlying regulatory mechanisms remain relatively limited. Methods In this study, three widely cultivated wheat cultivars in the Jianghuai region—Nongmai 77, Nongmai 88, and Yangmai 39—were used as experimental materials. A field-based experimental platform simulating extreme heat conditions was employed, with two treatments established: normal ambient temperature (control) and extreme heat. Continuous measurements of leaf temperature, diurnal variations in stomatal conductance, photosynthetic rate, and relative chlorophyll content were conducted to elucidate cultivar-specific responses of leaf temperature and photosynthesis to extreme heat. Important findings The results showed that mean air temperature increased by 2.7 °C; however, wheat leaf temperature did not change significantly, resulting in a significant reduction in the leaf-to-air temperature difference during the extreme heat treatment. Under extreme heat conditions, the mean stomatal conductance (gs) of Nongmai 77, Nongmai 88, and Yangmai 39 increased by 59.3%, 56.7%, and 32.4%, respectively, compared with the control. Diurnal analysis indicated that the largest increases in gs occurred at 13:00 and 15:00, with increments of 67.4% and 26.1%, respectively. Under the coupled conditions of reduced radiation and elevated air temperature, extreme heat significantly increased stomatal conductance (gs) and leaf transpiration rate, suggesting that wheat may alleviate the adverse effects of high temperature on leaves by enhancing transpiration. Extreme heat had no significant effects on relative chlorophyll content or saturated photosynthetic rate, but it significantly reduced leaf-scale water use efficiency. Overall, wheat leaves exhibited strong acclimation to the extreme heat conditions examined in this study, primarily by enhancing transpiration and increasing latent heat flux to maintain relatively stable leaf temperature and photosynthetic rate, albeit at the cost of increased water consumption and reduced water use efficiency.

Aims To investigate the effects of nitrate concentration on anthocyanin accumulation and spatial distribution in Mikania micrantha, and to reveal molecular mechanisms of adaptation to nitrogen fluctuations through secondary metabolic regulation. Methods Controlled experiments with six nitrate concentrations (0, 0.5, 5, 10, 20, 40 mmol L–1) were conducted to measure anthocyanin content and spatial distribution in main stems and branches, combined with transcriptome analysis of key metabolic pathway genes and transcription factors. Important findings The results show that under low nitrogen conditions (0–0.5 mmol L–1 NO₃⁻-N), both the main stems and branches accumulated substantial anthocyanins to enhance stress resistance. By contrast, in treatments with medium-to-high nitrogen (5–40 mmol L–1 NO₃⁻-N), anthocyanin content in the main stems significantly decreased (by 43.1%–73.7%), turning them light green, while the branches remained red but with reduced anthocyanin levels, indicating a "main stem growth-branch defense" allocation strategy. Transcriptomic analysis revealed that 5 mmol L–1 NO₃⁻-N suppressed the expression of key anthocyanin biosynthesis genes (PAL, CHS, CHI, F3H, ANS, UGFT) in the main stems (downregulated by 39.2%–99.9%), while upregulating lignin synthesis genes (HCT1, CCoAOMT) and terpenoid metabolism genes (TPS11, TPS7). Additionally, nitrate modulated the expression of transcription factors (MYB [HHO2], bHLH [PIF3]) and sucrose metabolism genes (SPS1), influencing the secondary metabolic network. This study demonstrates that M. micrantha dynamically regulates anthocyanin allocation between main stems and branches, potentially to balance growth and stress resistance. This adaptive strategy might be a key mechanism contributing to its successful invasion in environments with fluctuating resource availability.

In recent years, persistently elevated concentrations of atmospheric ozone (O₃) have not only reduced plant productivity but also interfered with compound metabolism, leading to distortion of chemical signals, disruption of local ecological balance, and threats to the precision of symbiotic interactions between animals and plants, as well as to ecosystem service functions. This study investigated the impact of elevated ozone concentrations on plant chemical signaling and stomatal adaptation by comparing the volatile odor composition of receptive syconia and leaf stomatal characteristics of Ficus hispida in natural sites with high and low ozone concentrations in Guangzhou City. Using gas chromatography–mass spectrometry (GC-MS) analysis, a total of 43 volatile organic compounds (VOCs) were identified across both sites, with 32 compounds common to both. Terpenoids dominated the profile. Furthermore, the high-ozone site exhibited specific oxidized products such as Decanal, Sesquicineole, and Caryophyllene oxide. Non-metric multidimensional scaling (NMDS) analysis revealed significant spatial differentiation in VOC composition between the two sites (Stress < 0.2). Permutational multivariate analysis of variance (PERMANOVA) identified significant differences (P < 0.05) in the proportional composition of 12 shared compounds (Germacrene D, α-Amorphene, α-Humulene, (E)-β-Farnesene, α-trans-Bergamotene, (E)-Caryophyllene, β-elemene, β-Cubebene, trans-Linalool oxide, (E)-β-Ocimene, Indole, Hex-(3Z)-enyl acetate) between the sites. This indicates a significant alteration in plant volatile chemical signaling between natural sites with high and low ozone concentrations, potentially reflecting plant responses to ambient atmospheric conditions (e.g., rising ozone levels) or underlying adaptive strategies. Meanwhile, in the high-ozone plots, the stomatal length and area of Ficus hispida leaves significantly decreased, along with a reduction in chlorophyll content. This study reveals the changes in volatile chemical signals and stomatal physiological characteristics of Ficus hispida under natural high-ozone conditions, providing new evidence for understanding how ozone pollution may potentially disrupt plant-pollinator interaction networks by affecting interspecies chemical communication and plant stomatal features.

As a symbiont widely existing on the earth, mycorrhiza plays a vital role in plant growth, community construction, and soil nutrient cycling. Under the background of global change, the changes in its community and function profoundly affect soil carbon decomposition and the state of carbon sources and sinks. Currently, although there are many studies on mycorrhiza, due to factors such as the complex interaction between mycorrhiza and other elements in the soil, there are still significant limitations in our understanding of the mechanisms by which mycorrhizal types affect soil carbon sequestration and decomposition in the context of climate warming. By integrating relevant cutting-edge research results at home and abroad, this paper discusses the role of different mycorrhizal types (such as ectomycorrhiza and arbuscular mycorrhiza) in soil carbon sequestration, focuses on exploring the occurrence mechanism of mycorrhiza-mediated "nitrogen competition" and its impact on soil carbon decomposition, and analyzes the changes and mechanisms of mycorrhizal fungal communities and carbon sink functions in the context of climate warming. On this basis, the paper prospects the key directions that need to be focused on in future mycorrhiza-related research, in order to provide a scientific basis for accurately understanding the process of forest soil carbon cycling and conducting research on the relationship between mycorrhiza and carbon in ecosystems under the background of climate change.

Gross Primary Productivity (GPP) is a key component of the carbon cycle in terrestrial ecosystems, and its accurate simulation is crucial for understanding the variations of carbon dioxide in the atmosphere. Currently, there are numerous global GPP products developed based on different data sources and models, but systematic assessments of their performance in the Tibetan Plateau are lacking. Methods In this study, we collected GPP data from 17 eddy covariance flux towers on the Tibetan Plateau and comprehensively evaluated the accuracy of 8 global GPP products (GPPGOSIF, GPPNIRv, GPPMOD17, GPPVPM, GPPGLASS, GPPTL-LUE, GPPPML, and GPPBESS) in alpine meadows of the eastern and central Tibetan Plateau using three indicators: coefficient of determination (R2), relative root mean square error (RRMSE), and relative bias (RBIAS).The results showed that GPPVPM (R2=0.60, RRMSE=75.39%, RBIAS=8.73%) and GPPGOSIF (R2=0.58, RRMSE=81.53%, RBIAS=24.94%) generally exhibited relatively high accuracy and were more suitable for the alpine meadows of the Tibetan Plateau. Moreover, the accuracy of GPP products varied significantly in space and time, manifested as follows: seasonally, the accuracy was higher in summer and autumn than in spring; in terms of ecosystem types, typical alpine meadow showed better accuracy than other meadow ecosystems; regarding permafrost types, the accuracy was higher in permafrost zone than in seasonal frost zone; in climate zones, semi-humid region demonstrated higher accuracy than semi-arid region; in terms of drought conditions, the accuracy is greater in non-drought months compared to drought months. This study reveals the uncertainties of global GPP products in the alpine meadows of the Tibetan Plateau and provides important insights for selecting GPP data and improving GPP simulations in this region.

Aim Phosphorus(P) is one of the important nutrient elements to maintain plant growth and the integrity of terrestrial ecosystem, and is the limiting nutrient element second only to nitrogen in global arid ecosystems. The storage and supply capacity of phosphorus is extremely important for the healthy growth of plants, the survival of microorganisms and the stability of the soil ecosystem. Given the scarcity of phosphorus in terrestrial ecosystems and the fact that the form of inorganic phosphorus can determine the availability of soil phosphorus, studying the effects of different grassland utilization patterns on soil inorganic phosphorus components under changes in precipitation intervals is of great significance for promoting the sustainable development of grassland ecosystems. Methods This study employed a combination of field in-situ experiments and laboratory analyses to compare the effects of three grassland utilization methods (grazing, cutting, and enclosure) on soil Pi fractions in temperate meadow steppe under different precipitation intervals. Important findings The results showed that precipitation intervals and grassland utilization methods directly altered soil Pi content (r = 0.38, p < 0.01) and indirectly influenced Pi fractions through modifying soil organic carbon (SOC) (r = 0.21). SOC exhibited significant positive correlations with total phosphorus (TP) (r = 0.51, p < 0.01), which in turn positively regulated Pi fractions (r = 0.61, p < 0.001), particularly Al-P and Fe-P (p < 0.05). Additionally, SOC strongly influenced microbial biomass C, N, and P (r = 0.69, p < 0.001), which moderately regulated Pi fractions (r = 0.04). Dominant bacterial phyla (Actinomycetota, Pseudomonadota, Acidobacteriota, and Planctomycetota, collectively >70%) significantly correlated with SOC and microbial biomass nitrogen (MBN) (p < 0.05) in regulating Pi fractions. Planctomycetota further showed significant positive correlations with microbial biomass carbon (p < 0.01) and Fe-P content (p < 0.05). Ascomycota dominated fungal communities across treatments, exhibiting direct positive effects on Ca-P (p < 0.01). Chytridiomycota and Basidiomycota influenced Pi fractions through contrasting effects on available phosphorus (AP), with O-P showing significant positive correlation with AP content.

Aims Leaf and root hydraulic traits play an important role in the hydraulic architecture of trees, but the differences between leaf and root turgor loss point (TLP) and their relationship with the stomatal closure point (Ψclose) are not fully understood. And the potential relationship between leaf and root morphological characteristics, non-structural carbohydrate (NSC) content and turgor loss traits among different tree species is not clear. Methods Five coniferous tree species and seven broad-leaved tree species common in the loess gully region were selected as the research objects, and the differences in their TLP, Ψclose and NSC contents of leaves and fine roots were compared, and the relationship between leaf and fine root morphology and TLP was analyzed. Important findings The TLP and water capacity of leaf and fine root of coniferous tree species were significantly lower than those of broad-leaved species, and the specific leaf area and specific root length of coniferous species were also significantly lower than those of broad-leaved tree species. The Ψclose of coniferous tree species was significantly higher than that of broad-leaved tree species, and the soluble sugar content and leaf NSC content of leaf and fine roots of coniferous tree species were significantly higher than those of broad-leaved tree species. The leaf TLP of all tree species was significantly lower than that of fine roots. There were significant correlations between specific leaf area and leaf TLP, specific root length and fine root TLP, and leaf TLP and fine root TLP in all tree species. The results suggested that conifer species had stronger ability to maintain leaf and fine root turgor pressure, and their stomata were more sensitive, which made coniferous species more tolerant to the arid and water-scarce environment in this area. And the results of this study also suggested that there were differences in the relationship between turgor loss points and stomatal closure points between coniferous and broad-leaved tree species.

Aims Root is the key organ for plants to absorb nutrients and water. Investigating the root interactions of mixed-species trees is of great significance to reveal the mechanism driving productivity enhancement in mixed-species stands. Methods A pot experiment was set up by co-planting Cunninghamia lanceolata and Michelia macclurei seedlings. We established three co-planting modes: No separation (NB), 30 μm nylon film separation (MB) and plastic membrane separation (PB), and two controls: C. lanceolata monoculture(MC) and M. macclurei monoculture(MM). The photosynthetic parameters, root morphology and physiological characteristics of seedlings were determined. Important findings The results showed that: 1) the co-planting significantly increased stomatal conductance, transpiration rate and intercellular CO2 concentration (P < 0.05), but did not change the net photosynthetic rate (Pn) of M. macclurei ; 2) Compared with monoculture treatment, mixed planting significantly increased root length, dry mass, surface area, root average diameter, volume, tissue density and root tip number of C. lanceolata (P < 0.05); 3) The root length, root dry weight, specific root length, specific root surface area, root volume and average root diameter of M. macclurei were significantly higher under PB than other treatments (P < 0.05); 4) The mixed treatment significantly reduced the length, surface area and volume of small fine roots (0.0 < D ≤ 0.5mm) of M. macclurei; 5) Under mixed planting treatment, the soluble protein content, malondialdehyde content and antioxidant enzyme activity of C. lanceolata increased significantly. The soluble protein content and malondialdehyde of M. macclurei decreased significantly, but the activity of antioxidant enzymes increased significantly. The findings clarified the effects of interspecific root interactions between C. lanceolata and M. macclurei on the seedling root growth, further revealed mechanisms driving productivity enhancement in mixed-species plantation. This provides empirical evidence for precision silviculture in subtropical mixed plantations.

Aims Rodent disturbances significantly affect the respiration of alpine meadow ecosystems. However, the severe scarcity of field measurements has critically limited our understanding of how widespread rodent disturbances influence alpine meadow Re flux dynamics, particularly given that existing observations remain extremely sparse and predominantly confined to the growing season. Conducting year-round, high-resolution in situ Re flux measurements is therefore essential to assess the impacts of rodent bioturbation on soil Re emissions in alpine meadow and elucidate the underlying mechanisms. Methods This research utilized the static chamber-gas chromatography method to perform a year-long investigation spanning October 2022 to October 2023, examining the variations in ecosystem respiration flux between two heterogeneous land types: healthy meadow (HM) and zokor mounds patches (ZM), located in the northeastern Tibetan Plateau. Additionally, the study sought to elucidate the potential mechanisms underlying ecosystem respiration emissions. Important findings Following disturbance, the annual cumulative Re flux at ZM (5906.03 ± 209.20 kg C ha-1 yr-1) decreased significantly by 27.60% (p < 0.05) compared to HM (8157.52 ± 305.30 kg C ha-1 yr-1), with reductions of 28.64% and 16.39% observed during the growing and non-growing seasons, respectively. The temperature sensitivity (Q10) of HM and ZM exhibited minimal differences at annual (6.11 ± 0.31 vs. 5.78 ± 0.41) and growing-season (4.13 ± 0.85 vs. 4.10 ± 0.61) scales. However, HM demonstrated significantly higher Q10 values (11.90 ± 1.80) than ZM (4.76 ± 1.00) during the non-growing season (p < 0.05). Seasonal Re variation patterns remained consistent across treatments and were not exclusive to post-disturbance conditions. Soil temperature and soil water content exerted combined effects as primary driving factors, with soil temperature explaining 59.7-85.3% of Re emissions. This study demonstrates that rodent disturbance significantly suppresses alpine meadow ecosystem respiration, providing critical insights for grassland carbon cycle modeling and ecosystem management.

Abstract Aims Investigating the relationship between individual tree size and carbon sequestration rate in temperate forest communities provides a scientific basis for understanding the nature of tree growth and enhancing the carbon sink capacity of these ecosystems. Methods Based on the fixed monitoring data of 125,000 standing trees in temperate coniferous and broad-leaved mixed forests in different regions of Northeast China, the relationship between tree carbon sequestration rate and tree size was analyzed, and the tree species in each region were divided into four tree species groups according to their life forms and regeneration modes: (1) Understory tree species with L-shaped diameter distribution(UNL); (2) L-shaped subcanopy species (SUL); (3) bell-shaped subcanopy species (SUB); (4) Canopy species (CAB) with bell-shaped diameter distribution. Partial correlation analysis was used to quantify the effects of tree size, neighborhood competition, and species diversity on the carbon sequestration rate of individual trees. Important findings Carbon sequestration rate continuously increased with tree size. The trend of carbon sequestration rate with tree size is similar in different tree species groups, but there are differences in growth rate, with the fastest growth rate in the CAB group and the slowest growth rate in the UNL group. Tree size is the main factor affecting carbon sequestration rate and is significantly positively correlated with carbon sequestration rate (p < 0.001). The effects of neighborhood competition and species diversity on carbon sequestration rate vary among tree species groups, usually showing a significant negative correlation (p < 0.001). Conclusion This study reveals the factors influencing carbon sequestration rates of trees in temperate mixed coniferous and broad-leaved forests, highlighting the significant carbon sequestration role of large-diameter individuals. Our findings provide further insights into the nature of tree carbon sequestration rates and offer a theoretical foundation for sustainable forest management and the restoration of carbon sink functions.