Drought represents a paramount abiotic stressor constraining global agroforestry productivity. Plants have evolved multifaceted adaptive strategies involving active modulation of symbiotic microbial communities to mitigate drought stress. These plant-associated microbes enhance plant drought adaptation via five principal mechanisms: (i) extracellular polymeric substance-mediated biofilm formation on plant surface enhances hydroregulation and edaphic structural stability; (ii) osmoprotectant biosynthesis (e.g., proline) maintains cellular osmotic equilibrium; (iii) synthesizing antioxidants to reduce damage from reactive oxygen species and oxidative stress; (iv) regulating plant phytohormone metabolism by secreting hormones (e.g. indole-3-acetic acid) and 1-aminocyclopropane-1-carboxylic deaminase; (v) emitting signaling molecules (e.g. volatile organic compounds, hormones and enzymes) to activate plant drought adaptation. Future researches should focus on the development of host-specific drought-adaptive microbial consortia while elucidating phyllosphere–rhizosphere microbiome crosstalk, ultimately harnessing translational microbiome engineering to evaluate their efficacy in multi-environment agricultural systems.

We screened 161 eligible papers of experimental data across the Tibetan plateau for Meta-analysis, in order to systematically assess and validate potential application of plant resource allocation strategies, such as the optimal allocation hypothesis, the isometric allocation hypothesis, and the allometric allocation hypothesis under environmental changes, and to explore the effects of environmental factors (temperature change, grazing intensity) on plant resource allocation strategies in alpine grassland ecosystems on the Tibetan Plateau. Overall, we found that the aboveground and belowground growth relationship in alpine grasslands follows the allometric growth hypothesis, which was unaffected by warming, grazing and their interactions. In addition, the biomass transferred between aboveground and belowground, the former was decreased, while the later was increased under warming condition in alpine steppe implies that the resource allocation strategy in alpine steppe grassland may potentially follow the optimal allocation hypothesis. We further found that the effect of soil properties on biomass, not the biomass allocation, was different under warming and grazing condition in alpine grasslands, which further conforms the above conclusion. In addition, warming helped to mitigate the negative effects of grazing, which indicated that the interaction between warming and grazing is important in alpine grassland ecosystems. Overall, results of this study are of theoretical significance for understanding how moderate grazing affects the growth of plants in alpine grasslands under changing climate.

Tree allometric models based on height (H) and diameter (D) are the most commonly used method to estimate forest biomass. Environments and stand characteristics are recognized to affect tree allometries. However, few studies have considered to incorporate these effects into allometric models, which restricts the use of these models in a wide domain. Adopting the power-law function Y = aG^b as a basic model where Y is either tree height or biomass and the corresponding G is tree diameter D at breast height or D²H, we developed a two-step approximation procedure to quantify the effects of environments and stand characteristics on allometric coeffcients a and b for Cunninghamia lanceolata and Pinus forest in China. Results show that most of the allometric coeffcients are dependent on stand characteristics for C. lanceolata forest, and on mean annual temperature, stand age and latitude for Pinus forest. The allometric models via the two-step approximation Y = f(α + α_jx_j) G^{f (β+βixi)} (x_j or x_i are key drivers associated with environments and stand characteristics. α, α_j,β and β_i are regression coeffcients) considerably improved the accuracy of tree height and biomass estimation. Compared to the basic model, the second approximation models signifcantly reduced the mean absolute bias between the observed and computed values by 25%–34% for C. lanceolata and by 21%–26% for Pinus forest, respectively. Our results highlight the necessity of incorporating environments and stand characteristics into the allometric models and provide a universal method to accurately estimate H-D-based tree biomass across a wider domain.

Interspecific plant–soil feedback (PSF)—the influence of soil conditioned by one plant species on another—is key to ecosystem processes but remains challenging to predict due to complex factors like species origin and phylogenetic relatedness. These aspects are underexplored, limiting our understanding of the mechanisms driving PSFs and their broader implications for ecosystem functioning and species coexistence. To shed light on the role of plant species origin and phylogenetic distance in interspecific PSFs, we conducted a greenhouse experiment with 10 native responding species and soils conditioned by 10 native and 10 exotic species resulting in 20 species pairs. These pairs represented a range of phylogenetic distances between both species, spanning up to 270 million years of evolutionary history since their last common ancestor. Conditioning by both native and exotic species reduced biomass production, with stronger inhibition observed for native-conditioned soils. Native-conditioned soils also exhibited lower phosphorus levels, higher basal and specific respiration, and greater cation exchange capacity, base saturation, and magnesium content compared to exotic-conditioned soils. Contrary to expectations, phylogenetic distance did not influence PSFs, regardless of conditioning species origin. Our findings suggest that co-evolution drives native plants to foster microbial communities with low carbon-use efficiency, highlighting soil biota’s critical role in PSFs. This advances our understanding of interactions between plant species origin and microbial communities and underlines the importance of microbial management for promoting native species and controlling invasives. The lack of phylogenetic distance effects aligns with prior studies, indicating evolutionary relatedness alone does not reliably predict PSF outcomes.

Understanding the driving mechanisms of forest changes is of great significance for developing effective adaptation strategies to mitigate the impacts of climate change and human activities on ecosystems. This study used Theil–Sen median trend analysis, Mann–Kendall test, contribution rate decomposition, partial least squares, geodetector and residual analysis to explore the impact of climate change and human activities on the forest coverage area and NDVI of the Altai Mountains. Results show that changes in forest cover are driven by both forest management policies and climate change. Among them, forest management policy is the main factor. However, there are differences in the driving mechanisms in different altitude zones: in the alpine and subalpine zones, the promoting effects of natural death and climate change bring the forest coverage area toward a dynamic balance, while under the combined effects of human activities and climate change, the forest coverage area in the low mountain zones shows an expansion trend. For forest NDVI, the analysis results of the six scenarios show that the joint action of climate change and human activities promotes the growth of forest NDVI in the largest proportion (50.20%); the impact of climate change on forest NDVI is greater than that of human activities, and most of it is a promotion effect (30.28%). Forest degradation is mainly caused by human activities (19.39%), especially in the edge areas of the forest. Among climate factors, precipitation and snowmelt water are the main controlling factors for forest growth. Snowmelt water from March to April is an important water source before the growing season. This study provides the important scientific basis for forest management and strategic planning in the Altai Mountains.

Invasive plants alter soil microbial communities and physicochemical properties through chemical inputs from litter, root exudates and leachate, impacting a range of soil processes, but precise effects are poorly understood. We investigated the little effects of Solidago canadensis, a common invasive species in China, on soil microbial communities under natural conditions. Experimental treatments included S. canadensis seedling density (1 and 2 plants/pot) and litter quantity (10 and 20 g/pot), with control groups containing no plants or litter. After 120 days, soil samples were analyzed for physico-chemical properties, GC–MS chemical composition, and bacterial community composition using high-throughput sequencing. Results showed that S. canadensis seedlings and litter inputs significantly increased soil pH, soil organic matter (SOM), and total nitrogen (TN), while phosphorus and potassium remained unchanged. We identified 66 chemical compounds, predominantly ketones, alcohol, aldehyde, hydrocarbon, ester, acid, terpenoids and alkaloids, associated with the presence of S. canadensis, alongside shifts in dominant bacterial genera including Sphingomonas, Acidobacteriales and Gemmatimonas. Rarer genera under the invasive treatment species, such as Candidatus, Rhodoplanes and Novosphingobium, were positively correlated with soil TN, pH, and SOM. Collectively, these findings demonstrate that allelochemical inputs from S. canadensis litter and root exudates significantly reshape soil properties and microbial communities, with potential implications for ecosystem dynamics and invasion success.

Grasslands are highly diverse ecosystems providing important ecosystem services, but they currently face a variety of anthropogenic stressors simultaneously. Quantifying grassland responses to global change factors (GCFs) is crucial for developing effective strategies to mitigate the negative impacts of global change on grassland communities and to promote their resilience in the face of future environmental challenges. We conducted a field experiment in the Songnen grassland, northeastern China, to test the combined effects of 0, 1, 2, 4, 6, and 8 GCFs, including fungicide, herbicide, insecticide, antibiotic stress, heavy metal pollution, light pollution, microplastic pollution, nitrogen deposition, tillage disturbance, and increased precipitation. We found that within one year, the increasing number of GCFs negatively impacts both the productivity and diversity of grassland communities. In comparison to exposure to a single GCF, exposure to 8 GCFs led to a reduction in productivity and species richness by 42.8% and 42.9%, respectively. Furthermore, these negative effects seem to be linked to the reduction of dominant species and the concurrent increase in neonative species (i.e., species that have expanded their geographic range into a new area without direct human assistance, but as an indirect consequence of human-induced environmental changes). The results of hierarchical diversity-interaction modeling suggested that the adverse impacts of an increasing number of GCFs on community productivity and diversity are attributable to both the specific identities of GCFs involved and their unique pairwise interactions. The results suggest that grasslands may quickly lose stability and degrade more rapidly in response to multiple co-occurring GCFs. Greater efforts should be made to conserve the functions and services of grassland ecosystems by reducing the impacts of human activities.

Terrestrial plants are colonized by various microorganisms in the rhizosphere, phyllosphere and endosphere. Variations of microorganisms between these niches could affect plant performance. While studies have indicated that microorganisms associated with invasive plants may facilitate their invasion success, niche effects on the composition, function and co-occurrence network of invasive plant microbiomes remain poorly understood. In this study, we investigated the bacterial and fungal communities in the rhizosphere soil, root and leaf endospheres of two invasive plants, Flaveria bidentis and Eclipta prostrata. Flaveria bidentis is a recently introduced species (introduced in 2001), whereas E. prostrata has been invaded in China for over 1000 years. We found that microbial community of F. bidentis and E. prostrata harbored more specialists, fewer unique amplicon sequence variants (ASVs), and lower diversity and network complexity in the leaf endosphere than that in the rhizosphere soil. Moreover, the bacterial and fungal communities in the rhizosphere soil, root and leaf endospheres of F. bidentis were more diverse, included more unique ASVs, and had a higher network complexity than those of E. prostrata. Predicted functional profiles revealed that there were more beneficial bacteria and fewer pathogenic fungi associated with F. bidentis than those with E. prostrata. These results demonstrate that there is a significant niche differentiation in the two invasive plant microbiotas, and this work may also indicate potential impact of residence time of invasive plants on plant-microbe interactions.

The decomposition of deadwood is a crucial process for the accumulation and sequestration of soil organic carbon (SOC) in forest ecosystems. However, the response of SOC to different decay classes of deadwood and the underlying mechanisms remain poorly understood. Here, we investigated the dynamics of SOC, soil properties, extracellular enzyme activities, and phospholipid fatty acid biomarkers across five decay classes (ranging from 1 to 5) of Masson pine (Pinus massoniana Lamb.) downed deadwood in a subtropical–temperate ecotone forest in Central China. Our results revealed a nonlinear response pattern of SOC along the deadwood decomposition gradient, with the maximum value at the decay class 4. Soil available nitrogen content, bacterial biomass, fungal biomass, the ratio of fungal-to-bacterial biomass, cellulase, activity and ligninase activity all increased with the intensification of deadwood decay, while soil pH decreased. The increase in SOC content was associated with a direct positive effect of bacteria and both direct and indirect positive effects of fungi by cellulose activity, but ligninase activity showed no significant relationship with SOC content. These findings suggest that cellulose and microbial biomass are key determinants of soil C formation and sequestration during deadwood decomposition. This study highlights the importance of the nonlinear response of SOC to deadwood decay, providing valuable insights for predicting future carbon-climate feedbacks.

China represents a significant global hotspot for species in the family Fagaceae, which are widely distributed across the country and play a crucial role in various ecological and social systems. As the global cliamte is changing rapidly, predicting the future distribution and richness of these species in China holds substantial importance. This study presents the first national-scale assessment of the future distribution of 243 Fagaceae species in China, utilizing ensemble species distribution models (SDMs) for the 2050s and 2070s under various climate change scenarios. The SDM projections indicate notable changes in the distribution of Fagaceae species, characterizing with an overall decline in the distribution area, an upward migration in elevation and a northeastward shift in their range. These changes are expected to significantly alter the spatial pattern of species richness, creating possible refugia in the southwestern mountainous regions and the western Qinling Mountains. We further revealed that a considerable amount of China’s natural reserves will show decreased richness of Fagaceae under climate change. Our study systematically evaluates the impact of future climate change on the distribution of Fagaceae species in China, potentially helpful for conservation planning of these species in China.

Chinese fir (Cunninghamia lanceolata (Lamb.) Hook.) monoculture plantations account for 17.4% of the total plantation area in China. The decomposition of Chinese fir litter plays a fundamental role in maintaining nutrient cycling and soil fertility in these plantations. Here, we conducted a continental synthesis based on 64 studies to estimate the mass loss and release rates of carbon (C) and nutrients (including nitrogen (N), phosphorous (P), potassium (K), calcium (Ca) and magnesium (Mg)) during the first year of Chinese fir litter decomposition. The average mass loss rates of needle, twig, root and cone litter were 0.503, 0.319, 0.551 and 0.372 year^-1, respectively. The decomposition rates of C and cellulose for needle litter were 0.649 and 0.801 year^-1, respectively, while those of K, Ca and Mg were 2.27, 0.852 and 0.551 year^-1, respectively. Decomposition rates were strongly influenced by mean annual temperature, soil N concentration and the initial C/N ratio of the litter. Climate warming and elevated ultraviolet-B radiation accelerated mass loss of Chinese fir litter, while increased N deposition and acid rain reduced it. However, elevated N deposition facilitated nutrient release from decomposing Chinese fir litter. These results provided a comprehensive assessment of Chinese fir litter decomposition, which is crucial for understanding soil biogeochemical cycles and improving soil fertility in Chinese fir plantations under global change scenarios.

Ecological theories and field observations indicate a strong allometric relationship between plant biomass and leaf area. Here, we aimed to rigorously investigate how this allometry can predict the biomass responses to global warming. We conducted a global synthesis on a dataset of 188 species from warming experiments. The reliability of metabolic scaling theory (MST) and functional equilibrium theory (FET) was tested by estimating an allometric coefficient (β) under a Bayesian framework. The results showed that the high β in areas suffering low precipitation was consistent with both theories, while the high β in areas suffering low-temperature stress was consistent with the MST but not the FET. These differences in β between ambient and stressed environments might be derived from the hydraulic constraints in stressed environments. Using general allometry across all species explained 58% of the total variance in the warming responses of plant biomass. The predictive power was not largely improved when factors, such as plant functional type, mean annual temperature and precipitation, warming magnitude, and other experimental treatments, were considered. The predictive error was primarily due to the theoretical assumptions that are based on long-term adaptation failing to capture the changes in specific leaf area (SLA) under rapid global warming. Fortunately, integrating the information on plant traits such as SLA and leaf biomass fraction in the ambient environment effectively improved the predictive power from 58% to 81%, highlighting the necessity of incorporating plant traits into ecosystem models for better predicting the ecosystem carbon cycle in a changing world.

Plant root-associated fungal communities play a pivotal role in enhancing plant growth, nutrient absorption, disease resistance and environmental stress adaptation. Despite their importance, the assembly processes of these communities remain inadequately explored. In this study, we utilizzzed high-throughput sequencing, co-occurrence network analysis and null models to examine the diversity, composition, interaction patterns and assembly mechanisms of the root-associated fungal communities of Mussaenda pubescens, a drought-tolerant shrub that thrives in stressful environments and is widely used for Chinese medicine. Our findings revealed pronounced regional and ecological niche-based variations in the diversity and assembly of total fungi and essential functional guilds, including saprotrophs, symbiotrophs and plant pathogens. Significantly, the fungal diversity of plant pathogens decreased with elevation, whereas total fungi, saprotrophs and symbiotrophs were minimally affected. Stochastic processes, such as dispersal limitation, played a significant role in fungal assembly. Furthermore, soil physicochemical properties, climatic conditions and spatial variables emerged as critical determinants of fungal community structure. This study enriches our understanding of the dynamics governing root-associated fungal community assemblies and underscores the factors essential for sustaining fungal diversity.

Canopy properties (e.g. canopy structure and spectral variables) strongly influence forest above-ground biomass (AGB). However, the importance of these canopy properties in driving AGB in natural forests, especially relative to other drivers such as plant species diversity and environmental conditions, remains poorly understood. We assessed the relative importance of canopy properties (structure and spectral variables) and plant species diversity (multidimensional diversity metrics and trait composition) in regulating AGB along environmental gradients (topography and soil nutrients) in a temperate forest in Northeast China, using UAV-based LiDAR and hyperspectral data. We found that the explanatory power of environmental conditions, plant species diversity, canopy spectral properties and canopy structure on temperate old-growth forests AGB was 3.8%, 8.0%, 4.1% and 13.3%, respectively. AGB increased with increasing canopy height and structural complexity. Canopy spectral diversity was a better predictor of AGB than traditional diversity metrics in old-growth forests. Canopy spectral composition also played an important role in explaining AGB in the secondary forests. In addition, plant phylogeny, functional diversity and the community-weighted mean of acquisitive traits had significant direct positive effects on AGB. Finally, topography and soil nutrient content indirectly influenced AGB through canopy properties and plant species diversity. Our study highlights the key role of canopy properties in influencing AGB. For future monitoring, regular monitoring with spectral and LiDAR data should be emphasized to provide real-time insights for forest management.

Plant and soil microbial communities jointly sustain ecosystem multifunctionality (EMF) in temperate grasslands, yet their relative contributions to EMF under grazing management remain poorly understood. We simultaneously investigated three temperate grasslands to assess the effects of grazing management, climate, edaphic properties, and plant and microbial communities (diversity and community composition) on EMF (quantified by potential soil nitrogen (N) mineralization, arbuscular mycorrhizal fungal infection rate, phospholipid fatty acid, soil total carbon (C) and N, inorganic N, and plant biomass). Using random forest modeling, we identified important predictors, followed by structural equation modeling (SEM) to disentangle their relative roles. The results showed consistent declines in plant diversity and EMF with increasing grazing intensity, while soil bacterial and fungal diversity exhibited minimal responses. Heavy grazing management significantly reduced the abundance of perennial forbs and rhizome grasses, but increased that of annuals and legumes. Concurrently, we observed a significant decrease in copiotrophic Proteobacteria abundance accompanied by an increase in oligotrophic Gemmatimonadetes abundance. Random forest modeling identified grazing intensity, climate, soil properties, plant diversity and community composition, and bacterial community composition as important predictors of EMF. SEM revealed that plant diversity was the dominant biotic predictor of EMF, exceeding the influence of microbial communities across all grasslands. Notably, aridity indirectly influenced EMF through plant diversity rather than direct regulation. These findings demonstrate that plant diversity primarily maintains EMF under grazing pressure, highlighting the importance of biodiversity-focused management strategies in temperate grassland conservation.

Fruit type influences seed dispersal mode and its effectiveness, reflecting plant adaptability to their environments. However, the large-scale patterns of fruit type distribution in forest communities and differences in the drivers of various fruit types remain unclear. We present a large-scale biogeographic model of woody plant fruit types along a latitudinal gradient through the data analysis of 30 forest dynamic plots. Results showed the following: (1) Fleshy and dry fruits exhibited distinct distribution patterns in large-scale space. The distribution of fleshy fruits was greater in tropical and subtropical zones, while dry fruits were more common in temperate zones. (2) Climatic factors primarily drove the geographical distribution of the fruit types of woody plants. Climatic and spatial factors exerted greater effects on the species richness of dry fruits compared with that of fleshy fruits. These results demonstrated the difference in the latitudinal gradient patterns of fleshy and dry fruits and identified the major abiotic environmental factors that drove their large-scale distribution, demonstrating the biogeography of the fruit types of woody plants.

The stability mechanisms of ecosystem functions have been a hot topic in ecology. However, in wetland ecosystems, the mechanisms by which biotic and abiotic factors interact to affect ecosystem stability in changing environments remain largely unclear. This study investigated the key factors and underlying mechanisms that regulate the spatial variability of wetland productivity by measuring community productivity, multiple components of biodiversity (i.e. species diversity, community functional composition and diversity) and environmental factors along a well-characterized gradient of wetland degradation in the lower reaches of the Yellow River. The results showed that the spatial variability of productivity in wetlands increased with intensified degradation. The spatial variability of wetland productivity was not related to species richness but was mainly affected by changes in community functional composition and diversity. Furthermore, degradation-induced changes in soil nutrients drove the spatial variability of productivity to increase with shifts in functional composition towards more conservative traits (i.e. higher leaf dry matter content and root tissue density), and to decrease with higher functional trait diversity. These findings reveal the driving mechanism of spatial variability in wetland productivity under degradation, and suggest that reduced nutrient availability, by altering plant resource strategies, can affect the spatial reliability of key ecosystem functions in wetlands.

During the restoration of degraded ecosystems, different shrub species often segregate along environmental water gradients. However, the physiological mechanisms driving this segregation remain unclear. To address this gap, we conducted a drought stress experiment (70%–80% field water holding capacity, CK; 40%–50% field water holding capacity, MD; 20%–30% field water holding capacity, SD) to explore the physiological mechanisms driving the dominance of different shrub species at various stages of ecosystem restoration. Salix gordejevii, a species dominant in the early stages of restoration with high water availability, and Caragana microphylla, a species dominant in the later stages under low water availability, were studied. The results showed that the living state index (LSI) of S. gordejevii was significantly lower than that of C. microphylla under drought stress (P < 0.05). Differences in plant hydraulics and water-use strategies explained how these species adapt to varying soil moisture conditions. Salix gordejevii employed a proactive water-use strategy with lower water-use efficiency (WUE) and reduced resistance to xylem embolism (xylem water potentials corresponding to 50% loss of conductivity, P₅₀), making it better suited to environments with more abundant water. In contrast, C. microphylla adopted a conservative water-use strategy. This strategy was characterized by increased WUE and enhanced resistance to drought-induced xylem embolism, which allowed it to thrive under more drought-prone conditions. Importantly, hydraulic efficiency (⁠K_leaf, K_s, and K₁) emerged as the primary determinant of living state in both S. gordejevii (47.30%) and C. microphylla (62.20%). The lower embolism resistance of S. gordejevii (⁠P₅₀ = 1.3 MPa) made it more susceptible to xylem cavitation, leading to a decline in hydraulic efficiency under SD. In contrast, C. microphylla’s higher embolism resistance (⁠P₅₀ = 2.3 MPa) enabled it to maintain stable hydraulic conductance across all drought treatments. These differences in hydraulic efficiency, driven by xylem embolism resistance, were key factors influencing shifts in shrub dominance during ecosystem restoration. These findings provide a physiological explanation for the replacement of shrub species during ecosystem restoration, where soil moisture is the main limiting factor.

Fine root dynamics are crucial for terrestrial ecosystem productivity and nutrient cycling. However, the effects of nitrogen (N) deposition on fine root dynamics in temperate ecosystems remain poorly understood. In this study, we used a meta-analysis to explore the general patterns and key drivers of fine root biomass and turnover in temperate forests and grasslands in response to N application. We found that N application significantly reduced fine root biomass compared to the control group (no N application), with notable differences across N forms. However, the impact of N application on fine root biomass remained consistent across ecosystem types, soil depths and root diameters. In terms of fine root turnover rate, N application had no significant overall effect, and the response did not vary across N forms, ecosystem types, soil depths or root diameters. However, significant differences were observed across methods for estimating fine root turnover rate. Multiple regression analysis showed that mean annual temperature (MAT) and experimental factors (including duration and N application rates) were the primary determinants of fine root biomass response to N application. In contrast, fine root turnover was not significantly influenced by any of the factors analyzed. Overall, our findings highlight the negative impact of N application on fine root biomass and the neutral effect on fine root turnover, and also suggest that find root dynamics are closely associated with experimental factors, including experiment duration and N application rate. This study provides an important advancement in understanding the feedback between root dynamics and global change, offering insights for developing management strategies to address belowground ecological processes under global change scenarios.

Phenological models are valuable tools for predicting vegetation phenology and investigating the relationships between vegetation dynamics and climate. However, compared to temperate and boreal ecosystems, phenological modeling in alpine regions has received limited attention. In this study, we developed a semi-mechanistic phenological model, the Alpine Growing Season Index (AGSI), which incorporates the differential impacts of daily maximum and minimum air temperatures, as well as the constraints of precipitation and photoperiod, to predict foliar phenology in alpine grasslands on the Qinghai–Tibetan Plateau (QTP). The AGSI model is driven by daily minimum temperature (T_min), daily maximum temperature (T_max), precipitation averaged over the previous month (PA), and daily photoperiod (Photo). Based on the AGSI model, we further assessed the impacts of T_min, T_max, PA, and Photo on modeling accuracy, and identified the predominant climatic controls over foliar phenology across the entire QTP. Results showed that the AGSI model had higher accuracy than other GSI models. The total root mean square error (RMSE) of predicted leaf onset and offset dates, when evaluated using ground observations, was 12.9 ± 5.7 days, representing a reduction of 10.9%–54.1% compared to other models. The inclusion of T_max and PA in the AGSI model improved the total modeling accuracy of leaf onset and offset dates by 20.2%. Overall, PA and T_min showed more critical and extensive constraints on foliar phenology in alpine grasslands. The limiting effect of T_max was also considerable, particularly during July–November. This study provides a simple and effective tool for predicting foliar phenology in alpine grasslands and evaluating the climatic effects on vegetation phenological development in alpine regions.

Floodplain wetlands have a signifcant capacity for carbon sequestration but are vulnerable to land use changes. Poplars are extensively planted in wetlands due to the increasing demand for wood products and bioenergy. Although the large biomass of poplar may increase the carbon stock in wetlands, their high transpiration rates may reduce soil moisture, thereby improving the aeration and facilitating the oxidation of organic materials. Therefore, the impact of poplars on wetland carbon stock remains uncertain and unexplored. Here, we investigated the effects of poplar plantations on biomass carbon stock (BCS) and soil organic carbon (SOC) stock in Dongting Lake wetlands, China, using native Miscanthus lutarioriparius vegetation as a control. Our results indicated that the BCS of middle-aged and near-mature poplar plantations (36.47–81.34 t ha⁻¹) was higher than that of M. lutarioriparius (8.31 t ha⁻¹), and it increased with stand age. The SOC stock within the 0–60 cm depth in young, middle-aged, and near-mature poplar plantations (130.32–152.58 t ha⁻¹) were higher than those in M. lutarioriparius (70.48 t ha⁻¹), but they did not increase with stand age. The BCS was positively associated with soil bulk density, while SOC stock was negatively associated with soil sand content. Overall, our fndings indicate that poplar plantations increase carbon stock in the Dongting Lake wetlands. Nevertheless, the longterm effect of poplar plantation on carbon sequestration in foodplain wetlands should be further investigated.

Studies on diversity–biomass relationships (DBRs) provide insights into the mechanisms underlying ecosystem functioning and services. While manipulative experiments indicate that both functional diversity and functional dominance influence biomass, with functional diversity often becoming the stronger predictor over time, their relative contributions during natural forest succession remain unclear. Here, we analysed tree data from 2010 to 2020 across early, middle and late-successional forests in subtropical China to investigate how the effect of taxonomic diversity on aboveground biomass (AGB) is related to shifts in the roles of functional diversity and functional dominance of five functional traits, corresponding to the complementarity and biomass ratio hypothesis. Our results showed that mean AGB increased with succession, reaching its highest at the middle stage. Taxonomic diversity influenced AGB primarily through its impact on functional properties rather than directly. From early to late-successional stages, functional dominance consistently emerged as the stronger predictor of AGB compared to functional diversity. Specifically, in earlier stages, the dominance of species with fast leaf economic traits directly and negatively impacted AGB, whereas, in the late stage, the dominance of tall species had a direct positive impact. Although functional diversity contributed increasingly to AGB in a positive manner during succession, its effect was primarily indirect, largely mediated through functional dominance. Overall, our findings support the biomass ratio hypothesis as the primary mechanism underlying DBRs throughout succession. This highlights the importance of functional dominance in driving forest biomass production and emphasizes the need to consider dominant species’ traits in forest management and restoration strategies.

Microbial necromass carbon (MNC) contributes largely to soil organic C (SOC) pool in terrestrial ecosystems. However, the pattern and underlying mechanisms of MNC and their contribution to SOC along elevational gradients are controversial due to montane ecosystems subject to environmental change. Here, in this study, we investigated the seasonal variation of MNC, its contribution to SOC, the necromass accumulation coefficient and the influencing factors across different elevations in the mountain forests ecosystem of Southwest China. Soil microbial biomass rather than MNC showed seasonal variations, this decoupling pattern was mainly attributed to higher soil extracellular enzymes (i.e. N-hydrolyzing enzyme) and C:N ratio, which accelerated the decomposition of MNC especially bacteria necromass C (BNC) during the humid and warm wet season. In contrast, the drought and cold conditions in dry season inhibited microbial activities and conversion to MNC. During the dry season, the MNC and MNC/SOC exhibited hump-shaped pattern along elevational gradients. The fungal necromass C (FNC) was positive with fungal biomass, indicating that living biomass may have a greater influence on the accumulation of FNC than BNC. On average, MNC constituted about 15% of SOC, with the contribution from FNC (11.9%) surpassing that from BNC (3.1%). The joint effects of soil pH and clay composition significantly influenced MNC dynamics along elevational gradients. These findings demonstrate that the rapid decomposition of BNC is the main way of MNC loss in wet season in the mountain forests ecosystem and further highlight the importance of microbial traits in MNC accumulation.

Traits and their correlation networks can reflect plant adaptive strategies. However, variations in traits and trait correlation networks across heteromorphic leaves within species remain largely unexplored. In this study, we systematically quantified a diverse array of leaf traits—spanning morphology, anatomy, physiology and biochemistry—among the striped, lanceolate, ovate, and broadly ovate leaves of Populus euphratica, aiming to elucidate the adaptive differences across these various leaf types. We found that the four heteromorphic leaves showed significant differences in leaf traits. From striped leaves to broadly ovate leaves, leaf size, leaf thickness, water use efficiency and catalase content significantly increased, while specific leaf area showed the opposite pattern. Principal component analysis and cluster analysis revealed distinct aggregation and clear demarcation of the four leaf types, indicating substantial variations in trait compositions and their distinct ecological adaptations. Plant trait networks varied significantly across the four leaf types, with the broadly ovate leaves exhibiting a fragmented network structure that enhances their modularity. This suggests strong resilience to disturbances and is consistent with the characteristic foliage on mature trees. Regardless of leaf type, nitrogen and phosphorus consistently emerged as hub traits within plant trait networks, underscoring their fundamental role in driving physiological processes and influencing phenotypic expression. This study meticulously delineates the variations in both individual leaf traits and trait correlation networks across the heteromorphic leaves of P. euphratica, significantly deepening our understanding of plant adaptive strategies.

Global warming and altered precipitation regimes may profoundly affect soil nitrogen (N) transformations. However, a comprehensive understanding of how soil N cycling responds to such climatic changes remains lacking, with few syntheses of field-based observations. Here, a meta-analysis was conducted using 755 paired data points from field observations worldwide to explore the effects of warming and altered precipitation on soil N transformation rates and to assess possible drivers of these effects. Warming positively affected the soil N mineralization and nitrification rates (+21.8% and +20.9%), but had no effect on the microbial immobilization rate. Similarly, increased precipitation accelerated soil N mineralization and nitrification (+10.2% and +9.4%), but did not alter microbial immobilization. In contrast, decreased precipitation did not affect any of the three N transformation rates. Moreover, warming effects on the N mineralization rate were mainly driven by the variations in soil moisture and soil total N content, while effects on the nitrification rate were regulated by changes in ammonia-oxidizing bacterial abundance. In addition, the effects of increased precipitation on the N mineralization rate were largely dependent on changes in soil moisture and experimental manipulation characteristics, while effects on the nitrification rate were shaped by mean annual precipitation, soil pH, ecosystem types and treatment duration. Overall, increased temperature and precipitation accelerated soil N cycling and increased soil N availability, but decreased precipitation did not. These findings may improve predictions of biogeochemical cycling under future climate change scenarios.

Leaf construction cost (LCC), a proxy for the energetic investment plants make to construct leaf biomass, indicates carbon investment strategies of plants across diverse habitats. However, large-scale variations in LCC and their correlations with climate and soil factors have yet been fully explored. To address this knowledge gap, here, we compiled a dataset comprising 442 species-site combinations, spanning nearly all vegetation types in China. We found that LCC exhibited substantial variation, ranging from 0.72 g glucose g⁻¹ to 1.93 g glucose g⁻¹, with an average of 1.25 g glucose g⁻¹. LCC was significantly higher in woody species compared to nonwoody species; however, there was no significant difference in LCC between evergreen and deciduous plants. LCC decreased with increasing latitude and longitude but increased with increasing altitude. Among bivariate LCC-environment relationships, LCC was positively correlated with mean annual precipitation and temperature but negatively correlated with temperature seasonality, precipitation seasonality, soil potassium content, and soil silt content. Collectively, climate and soil factors account for over 54% of the variance in LCC, with soil exerting a more significant influence than climate on LCC. This study offers an exhaustive analysis of the evident pattern of LCC over a large spatial scale, fostering a fresh perspective on functional biogeography and establishing the foundation for exploring the interplay between LCC, ecological functions, and macroevolutionary implications.

Unraveling the legacy effects of long-term climate warming is essential to for an integrated understanding of plant invasion success. However, knowledge regarding how these legacy influences invasive offspring and natural enemies remains lacking. This work was built on a long-term warming experiment established in 2012. Here, we selected invasive Solidago canadensis and performed a series of experiments to explore the effects of experimental warming on offspring S. canadensis from its native and invaded range, as well as the legacy effect of warming on three insect species, and three pathogens. The experience of long-term maternal warming facilitated the growth of offspring from invasive S. canadensis, regardless of the presence of insects or pathogens. This experience decreased insect growth when feeding on native S. canadensis, and inhibited pathogens when infecting invasive S. canadensis. Additionally, the presence of natural enemies could modulate the legacy effects of warming and population provenance. These results suggest that long-term climate warming could facilitate invasion success via coordinated increases in growth and defense, and that legacy effects of climate warming and maternal provenance are important for understanding the cascading effects of climate warming.

Understanding leaf phenology is essential for capturing forest dynamics, yet traditional monitoring methods fail to resolve vertically stratified phenology due to canopy occlusion and limited spatial coverage. To address this gap, we developed an integrated unmanned aerial vehicle and ground-fixed camera system enabling simultaneous monitoring of forest overstory and understory phenology. Deployed in a subtropical forest during 2017–2023, this system archived 0.075 m × 0.075 m resolution aerial imagery and hourly ground photography, tracking vegetation dynamics across community and species scales. Our system-derived Green Chromatic Coordinate was strongly correlated with Normalized Difference Vegetation Index (r = 0.82), Enhanced Vegetation Index (r = 0.91), Gross Primary Productivity (r = 0.95) and Leaf Area Index (r = 0.79 for overstory; r = 0.92 for understory) validating its effectiveness as a phenological proxy in subtropical forests. Critically, the understory exhibited delayed leaf maturation (16.2 days) and senescence (61.2 and 11.6 days for start and end of leaf falling, respectively) compared with the overstory, revealing a vertical ‘phenological escape’ phenomenon. These phenological mismatches buffered seasonal productivity fluctuates, by sustaining carbon uptake during overstory senescence. Our approach overcomes the limitations of fixed observation towers and satellite imagery by offering flexible, scalable and cost-effective monitoring of vertical stratification in forests. By quantifying vertical layer interactions, our approach advances predictive modeling of ecosystem–climate feedback and guides forest management under climate change.

Leaf chemistry plays a central role in structuring phyllosphere microbiomes. Plant populations often evolve genetic differences in leaf chemistry across region due to both abiotic and biotic selection pressures, including insect herbivory. Plants in invasive populations may reassociate with native specialist insects, providing an ideal system to examine how herbivory-mediated changes in plant chemistry affect phyllosphere microbiome. Here, we conducted a common garden experiment using Ambrosia artemisiifolia populations differing in leaf chemistry and reassociation history with a specialist beetle—Ophraella communa. We found that plant populations with a longer reassociation history exhibited stronger herbivore resistance and supported phyllosphere communities with higher alpha diversity and more complex composition. These changes were associated with shifts in concentrations of plant metabolites and the expression levels of corresponding biosynthetic genes. The abundance of the fungal pathogens, Golovinomyces, decreased with increasing herbivore resistance, while Pestaliopsis showed the opposite trend. Although reassociation history was linked to population latitude, climatic and soil conditions at the sites of origin also contributed to between-population variation in leaf chemistry and phyllosphere fungal community composition. Our study suggests that genetic differences in leaf chemistry among plant populations can strongly affect herbivore resistance and phyllosphere fungal communities. The observed alignment of reassociation history, chemical traits and phyllosphere fungal communities suggests that herbivore-mediated selection may be a key driver of microbial community evolution in invasive plants.

Alpine cushion plants are recognized as keystone species essential for sustaining plant communities and biodiversity. However, their contributions to the structures of plant–plant co-occurrence networks remain poorly understood. This study constructed plant–plant co-occurrence networks within cushion microhabitats at both regional and local scales in the Himalaya–Hengduan Mountains, focusing on the influences of multiple cushion plants in shaping plant–plant network structures. Results reveal that cushion plants significantly influence the network structures. Compared to random expectations, these networks display lower linkage density, weighted connectance and weighted nestedness (wNODF), but higher modularity, implying distinct organizational principles driven by cushion plant facilitation. Non-cushion plants show stronger associations with cushion microhabitats than with open ground microhabitats. Additionally, the spatial influence of cushion plants extends beyond their immediate canopies, highlighting their role in structuring surrounding plant assemblages. Moreover, the facilitation strength of cushion plants positively correlates with network metrics, indicating that network complexity increases with increasing facilitation by cushion plants. Simulations suggest that the loss of cushion plants would likely trigger cascading extinctions of associated non-cushion plants, particularly when high-degree centrality cushion species—those with the greatest network connectivity—are removed. These results highlight the keystone roles of cushion plants’ facilitation in supporting biodiversity via enhancing network complexity and robustness. Given the vulnerability of alpine ecosystem to environmental disturbances, our study emphasizes the urgent need to prioritize the conservation of cushion plant diversity. Future conservation strategies should adopt an integrated approach that protects not only individual cushion species but also the micro-communities they support.

Plant reproductive phenology is sensitive to climate change and has great implications for plant reproduction, community structure and ecosystem functions. Shifts in reproductive phenology under warmer temperatures have been widely studied, but how other global change factors, such as nitrogen enrichment and altered precipitation, interact with warming to influence phenology remains poorly understood. We conducted a field experiment in a Tibetan alpine meadow to examine the effects of warming, nitrogen addition, precipitation reduction and their interaction on plant reproductive phenology in 2017 and 2021. We found that warming interacted with precipitation reduction to affect reproductive phenology, independent of nitrogen addition. Specifically, warming led to an advance in flowering (3.5 days) and fruiting onset (3.8 days), but precipitation reduction offset this effect. Warming also extended the duration of flowering and reproduction but only when interacting with precipitation reduction. Nitrogen addition delayed the onset of flowering (2.1 days) and fruiting (1.8 days). Moreover, the effects of warming depended on the phenological niche of each species as well as its pollination mode. Early-flowering species advanced more in flowering onset than late-flowering species. The duration of flowering and reproduction of wind-pollinated species was prolonged while that of insect-pollinated species was shortened by warming. Our study highlights the necessity of considering the interaction of multiple factors in predicting phenological responses under global change and suggests that plant life-history traits should be taken into account in future studies.

This study used a method based on a spatial series in place of a temporal series, selecting Tamarix ramosissima shrubs at different developmental stages of coppice dunes as research subjects to investigate their chlorophyll fluorescence characteristics and non-structural carbohydrates (NSC). The results indicated that: (1) As coppice dunes developed, T. ramosissima showed a significant increase in photosynthetic pigment content alongside a decrease in actual photochemical efficiency (Y_(II)). Simultaneously, the reduction state of the plastoquinone (PQ) pool intensified, the apparent electron transport rate (ETR) increased, and the quantum yield of regulated energy dissipation significantly increased. These adaptations enabled T. ramosissima to dissipate excess light energy by enhancing its non-photochemical energy dissipation mechanisms. (2) Photosynthetically active radiation (PAR) and T. ramosissima leaf temperature (T_L) gradually increased during coppice dune development, whereas soil water content decreased, leading to increased stress on T. ramosissima and a subsequent decline in NSC content. This increased stress placed T. ramosissima at risk of ‘carbon starvation’, resulting in a gradual reduction in photosynthesis, biomass accumulation, and ultimately, mortality. (3) Correlations among various indicators of T. ramosissima were significant, with the highest degree of association and marked enhancement of synergistic effects in the growth and stable stages of coppice dunes. Comprehensive analysis revealed that high soil moisture content can alleviate water stress, improve light energy use efficiency and enhance the photosynthetic carbon assimilation process in T. ramosissima during coppice dune development.

Isolated individual processes of ecosystem carbon (C) cycles have largely shaped our understanding of C cycle processes under environmental change. Yet, in reality, C cycle processes are inter-related and hierarchical. How these processes respond to warming and grazing has rarely been investigated in a single manipulative experiment. Moreover, biodiversity loss is a major driver of ecosystem change under environmental change, but whether these responses are mechanistically linked to biodiversity remains unclear. Here, we performed a 5-year field manipulative warming with seasonal grazing experiment in an alpine meadow on the Qinghai-Tibetan Plateau. Our results showed that both warming and moderate grazing decreased net ecosystem productivity (NEP) by 42.1% and 38.3%, and their interaction decreased it by 56.2% during the summer grazing period. However, they had no significant effects on NEP during the winter grazing period. Overall, annual gross primary productivity (GPP) and ecosystem respiration (Re) were mainly determined by aboveground rather than belowground processes, and Re variation, which was mainly controlled by aboveground respiration explained 50% of the variation in annual NEP under warming and grazing. Moreover, lower species richness induced by warming and grazing caused smaller NEP with smaller net primary productivity and higher aboveground respiration. The responses of aboveground C cycle processes were greater than that of belowground C cycle processes, suggesting asymmetric above- and belowground responses to warming and grazing. Therefore, our findings suggested that there were higher GPP and Re with lower C sequestration (‘two high with one low patterns’) under warming and moderate grazing. Plant diversity modulated the responses of soil C sequestration to warming and grazing. It is essential to understand the underlying mechanisms of the effects of biodiversity on hierarchical C cycle processes under combined warming and grazing in the future.

Spring frost involves low temperatures in spring. Research shows cold snaps can alter herbaceous plants' biomass allocation, impacting grassland ecosystems. However, the exact effects of frost timing and severity remain unclear. This study simulated spring frost based on characteristics of spring frost on the northern slope of the Tianshan Mountains to examine how alfalfa (Medicago sativa) and ryegrass (Lolium spp.) adjust biomass allocation under varying frost intensities and timings, including interspecific differences in these responses. The findings revealed that (1) compared to the control group (which did not undergo low-temperature treatment), alfalfa was more sensitive to high-intensity spring frost, exhibiting a significant decrease of 13.6% in the root weight ratio and increases of 8.65% and 4.96% in the stem and leaf weight ratios, respectively. In contrast, ryegrass displayed an inverse trend, although the changes were not significant. (2) Early stage spring frost (immediately after thinning) significantly affected alfalfa biomass allocation, leading to an 11.28% decrease in the root weight ratio, whereas it also significant increases of 3.78% the stem weight ratio by 7.51% and leaf weight ratio. In contrast, late stage spring frost (applied on the 17rd day after thinning) had a relatively greater effect on ryegrass, with the root weight ratio increasing by 4.13% and the stem weight ratio decreasing by 4.18%. These findings reveal plants' distinct adaptations to cryogenic stresses, improving our understanding of herbaceous growth responses to extreme weather in arid zones and offering data to support grassland ecosystem services in Xinjiang.

Soil seed banks (SSBs) play an important role in the recovery and renewal of plant ecosystems. Numerous studies have explored the effects of grazing on the density, diversity, and composition of SSBs in grasslands. However, information on how different livestock species affect SSBs in semi-arid grasslands remains limited. Here we examined shift in species diversity, plant density, and community structure in both SSBs and aboveground vegetation in grasslands grazed by three livestock species under adaptive grazing management. We found that (i) Grazing by three livestock species increased plant density and species richness in both SSB and aboveground vegetation, with cattle grazing increased the most. (ii) Grazing leads to a notable increase in the seed density of annual and biennial plants while decreasing that of perennial plants in the upper 5 cm of soil; grazing also increases burial depth of seeds, with cattle and goat grazing significantly increasing the seed density of annual and biennial plants in the 5-10 cm soil layer, as well as that of perennial forbs in the 0-10 cm layer. (iii) The species composition of aboveground vegetation and SSB differed, but cattle grazing significantly increased the similarity between the two. Our results provide significant insights into SSB responses to three livestock species, and indicate that adaptive grazing management, which maintains grassland residual height above a certain level, may benefit the SSB and support vegetation regeneration.

The north-south transitional zone in central China is a climatic and ecological sensitive area, and the southern margin of Pinus tabuliformis distribution, yet regional response to climate has not been investigated. Here, we developed different regional chronologies from 14 samplings along an east-west gradient in the Funiu Mountains. Correlation results indicated that regional tree growth was mainly limited by temperature and precipitation in May, especially for YM. Temperature in the south and precipitation in the north were significant limiting effects, except in LCM, where trees were more limited by temperature in the south than precipitation in the north. The limiting effect of temperature in May gradually weakened from east to west, while the effect of precipitation in May was higher in YM (east) and BB (west) than in LCM (middle), and the promoting effect of precipitation in the north was stronger than that in the south. The self-calibrating Palmer Drought Severity Index (scPDSI) had significant positive correlations with tree growth from April to June, with the highest correlation in May. Tree growth increased in the 1970s–80s and then decreased after the 1990s indicated that the growth had degraded under global warming. This result supports the ecological marginal effect theory of growth degeneration of P. tabuliformis in NSTZ under global warming. However, whole regional tree growth also showed stronger recovery and resilience under extreme drought, the resilience basically restored to the pre-disturbance level after three years, which is obviously contradictory with tree growth trend and needs to be further studied.

Groundwater depth is a key environmental factor influencing the composition and structure of plant communities in coastal ecosystems. However, effects of the groundwater depth on the characteristics of shrub-grass communities in muddy coastal zones remain poorly understood. In this study, we conducted a field experiment to evaluate effects of the different groundwater depth (0.54, 0.83, 1.18, 1.62, and 2.04 m), on soil salinity, soil moisture, community diversity, distribution pattern and growth of the dominant Tamarix chinensis in the muddy coastal zone of Bohai Bay. Our results demonstrated that (1) the soil moisture and salinity gradually decreased with increasing groundwater depth (P < 0.001); Compared to the 0.54 m groundwater depth, soil moisture at depths of 0.83, 1.18, 1.62, and 2.04 m decreased by 16.02%, 24.83%, 54.40%, and 61.24%, and soil salinity decreased by 43.17%, 50.82%, 63.93%, and 73.41%, compared to 0.54 m, respectively. (2) The Simpson, Shannon-Wiener, Pielou and Margalef indices of the T. chinensis communities peaked at the 1.62 m groundwater table depth; (3) The dominant shrub T. chinensis population exhibited an aggregated distribution and optimal growth of T. chinensis shrubs occurring within the groundwater table depth range of 1.18 to 1.62 m; (4) The groundwater depth affected the diversity of the plant community primarily by influencing soil salinity rather than soil moisture; the dominant shrub T. chinensis promoted diversity of plant community, but this facilitation effect was inhibited by soil salinity. Our results suggest that the optimal groundwater depth for maintaining biodiversity falls within the range of 1.18 to 1.62 m. Shallow groundwater diminishes biodiversity both directly through soil salinization and indirectly by impairing T. chinensis’ facilitation of biodiversity. Therefore, regulating optimal groundwater table depth and protecting T. chinensis are critical for biodiversity conservation and ecosystem recovery in muddy coastal areas.

The mechanisms of plant adaptation to environmental gradients have been the focus of ecological research, with environmental stresses driving coordinated or differentiated regulation of plant functional traits. Plant resource acquisition involves root trait plasticity and mycorrhizal symbiosis. However, root trait plasticity along precipitation gradients and root-mycorrhizal trade-offs remain unclear. We conducted community surveys along a west-east precipitation gradient in four natural grassland communities (alpine desert steppe, alpine steppe, alpine meadow steppe and alpine meadow) on the plateau in northern Xizang Plateau. Six key root traits (root diameter, RD; root dry matter content, RDMC; root tissue density, RTD; specific root length, SRL; root branching intensity, RBI; and root length colonization percentage, RLC) were measured in 18 alpine plant species to investigate the coordination and trade-offs between root traits and mycorrhizal fungi along the precipitation gradient. Our results showed community-level declines in RDMC, RD, RTD and RLC with increasing precipitation, contrasting with elevated RBI and SRL. Functional groups exhibited distinct patterns: grasses and legumes demonstrated root-mycorrhizal trade-offs, sedges displayed synergy and forbs showed inconsistent responses. Divergent trends in plant root traits and mycorrhizal fungi were observed at the species level. Alpine plants in humid eastern meadows favored root elongation, while those in arid western desert steppe relied on radial growth and mycorrhizal fungal cooperation for resource acquisition. These findings highlight varied root absorption strategies among alpine plants along environmental gradients, supporting the importance of ecological niche diversification in maintaining alpine ecosystem diversity and stability.

Xanthium italicum is a globally distributed invasive weed that causes significant ecological and agricultural damage in the invaded areas. Although multiple mechanisms have been reported to contribute to its invasive success, the extent to which intraspecific differentiation and phenotypic plasticity facilitate this process in invaded habitats remains insufficiently understood. In this study, we conducted a common garden experiment with three nitrogen treatments: no nitrogen addition (NN), low nitrogen (LN: 2 g urea per pot), and high nitrogen (HN: 4 g urea per pot). Ten populations of invasive X. italicum (ten individuals per population, 100 individuals total) and native Xanthium sibiricum (excluded from the NN treatment due to seed limitations) were grown under each nitrogen treatments. Under the NN treatment, we detected significant phenotypic differences among different invasive X. italicum populations across six growth traits (root length, shoot length, crown breadth, base diameter, relative chlorophyll content, and biomass). Furthermore, when subjected to the LN and HN treatments, invasive X. italicum exhibited significantly higher phenotypic plasticity compared with that of native X. sibiricum in biomass and base diameter. Our findings suggest that phenotypic plasticity and intraspecific differentiation may play important roles in facilitating the invasive success of X. italicum in China, potentially increasing the risk of further biological invasion.