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: 1) EPS-mediated biofilm formation on plant surface enhances hydroregulation and edaphic structural stability; 2) Osmoprotectant biosynthesis (e.g., proline) maintains cellular osmotic equilibrium; 3) Synthesizing antioxidants to reduce damage from reactive oxygen species and oxidative stress; 4) Regulating plant phytohormone metabolism by secreting hormones (e.g., IAA) and 1-aminocyclopropane-1-carboxylic deaminase (ACCD); 5) 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.

The physiological response mechanisms of trees to climate change are complex, particularly across varying elevations and among different tree species. In this study, we collected tree ring samples from two dominant conifer species (Picea crassifolia and Pinus tabuliformis) at three elevations at the edge of the Tengger Desert. We used tree-ring width (TRW) and tree ring oxygen isotopes (δ¹⁸O_TR) to investigate how species and elevations affect their responses to climate change. Pearson's correlation analysis and relative importance analysis were used to study the specific response processes of the two conifers to climate. The results showed that the TRW was mainly controlled by SPEI during the growing season, which means that drought stress had the greatest effect on it. And δ¹⁸O_TR mainly responded to summer relative humidity (RH). Both TRW and δ¹⁸O_TR of Picea crassifolia showed higher sensitivity to climate change. This sensitivity is largely attributed to the rapid uptake of precipitation by its developed shallow-rooted root system, which allows it to retain the precipitation signal in both TRW and δ¹⁸O_TR. However, Picea crassifolia may be more susceptible to drought stress and growth decline or even death in the context of a warming region. Our results are important for understanding the impacts of climate change on forest ecosystems using multiple indicators and developing corresponding ecological conservation measures.

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.

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. F. 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 (ASV), 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.

Plant-soil feedback (PSF) effects of invasive plants are often regulated by abiotic factors, but whether soil water availability alters the impact of PSF on invasive plant growth and foliar herbivory remains unclear. We hypothesized that soil water content modifies PSF effects and then affects foliar herbivory. To test this, we established four soil water level treatments (soil surface elevated 0, 5, 10 or 15 cm above water) to examine their effects on PSF, growth traits, and herbivore resistance in the invasive weed Alternanthera philoxeroides. Results showed PSF was negative when soil surface was elevated 5 cm above water, but it was positive in other treatments. Soil condition, water treatment and their interactions significantly affected total biomass, leaf and branch numbers. As soil water content decreased, leaf nitrogen content increased, while the leaf C/N ratio decreased. Root nitrogen and C/N ratios were also affected by water treatment. Leaf mass per area and leaf area consumption rate were significantly affected by water content, with foliar herbivory being lowest when water content was at its minimum. Importantly, the effects of water availability on invasive plant performance and foliar herbivore resistance appeared to be stronger than those mediated by soil feedback. These findings suggest that soil water content, as a critical role, modifies the PSF effects on invasive plant performance, thereby indirectly affecting foliar herbivory.

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.

While substantial nitrogen (N) input from yak urine in intensively grazed grasslands on the Qinghai-Tibetan Plateau (QTP) is well documented, the species-specific responses of dominant forage plants—particularly regarding N uptake efficiency, environmental impacts, and associated microbial dynamics—remain poorly understood. This study investigated Elymus nutans (Gramineae) and Kobresia graminifolia (Cyperaceae), two ecologically dominant species, to elucidate the divergent nitrogen transformation features under urine deposition. During the growing season, we simulated yak urine input by applying 640 mL urine per 40 cm × 40 cm patch in natural grasslands. Over six weeks, we measured total plant N uptake and soil nitrous oxide (N₂O) emissions, and evaluated soil nitrification rates through a two-week indoor incubation experiment. To elucidate the underlying microbial mechanisms, we analyzed the abundance and composition of rhizosphere ammonia-oxidizing archaea (AOA) and bacteria (AOB). Results showed that K. graminifolia exhibited significantly lower soil nitrification rates and N₂O emissions but higher total N uptake compared to E. nutans. Furthermore, K. graminifolia soil had lower AOB and higher AOA abundances. Specifically, the relative abundances of Nitrosophaera and Candidatus Nitrosocosmicus within AOA, as well as Nitrosovibrio and Nitrosomonas within AOB, were higher in K. graminifolia soil. These findings indicate that variations in nitrifier populations may be key drivers of differences in N uptake and N₂O emissions across dominant forage species. This study provides valuable insights for developing effective management strategies for intensively grazed grasslands on the QTP.

The north-south transitional zone in central China is a climatic and ecological sensitive area, and the southern margin of Pinus tabulaeformis 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.

Elevation changes may affect intraspecific relationships or interspecific relationships among species. However, previous studies on Quercus variabilis have rarely investigated how its population interactions vary with elevation and how the factors affect them. Here, we examined the species relationships in Q. variabilis natural secondary forests by examining the three different elevation ranges (lower, medium, and higher elevation areas) by using the niche and the Hegyi competition method. As elevation increased, Q. variabilis strengthened its dominant position, and the overall association between populations shifted from positive to negative, as evidenced by a significant decrease in the positive-to-negative correlation ratio from 0.45 (85/191), 0.41 (80/196) to 0.32 (29/91), indicating that the interspecific relationship gradually transitioned from facilitation to competition. The ratios of intraspecific competition index to interspecific competition index were 3.09, 8.92 and 6.82, respectively, indicating that Q. variabilis forests had greater intraspecific competition compared to interspecific competition, especially in the medium elevation area. The intraspecific and interspecific competition in the lower and medium elevation areas showed a decreasing trend with the increase of diameter class, while the competition among individuals in higher elevation area became more stable. The SEM showed that soil properties were indirectly negatively correlated with the species’ competition through a significant negative effect on forest density, while community characteristics only had a significant negative effect on intraspecific competition. Our results demonstrated that elevation factors had decreased the intraspecific and interspecific relationships within Q. variabilis forests, which may provide insights for the effective conservation of Q. variabilis natural forests.

It is feasible for widely distributed mosses to monitor atmospheric nitrogen deposition in northern China, a global hotspot of atmospheric nitrogen pollution. Based on the nitrogen contents and nitrogen isotope values of mosses collected at Mengshan, Shandong Province in 2012, 2018, and 2022, we established a bottom-up method to calculate local atmospheric nitrogen deposition levels and source contributions. Moss nitrogen contents increased from 1.9 ± 0.2% in 2012 to 2.1 ± 0.4% in 2018, and to 2.4 ± 0.3% in 2022. On the contrary, moss nitrogen isotope values decreased from -7.5 ± 1.5‰ in 2012 to -8.6 ± 1.6‰ in 2018, and to -9.6 ± 1.3‰ in 2022. From 2012 to 2022, the total nitrogen deposition fluxes increased significantly (from 34.2 to 39.9 kg-N ha^-1 yr^-1), especially the fluxes of ammonium-nitrogen deposition increased. Based on results of Bayesian stable isotope analysis, volatilization-related ammonia (mainly from fertilizer applications and wastes) was predominant in ammonium-nitrogen deposition in the last decade. Fossil fuel nitrogen oxides contributed more than non-fossil fuel nitrogen oxides to nitrate-nitrogen deposition. Our results reveal that it is urgent to control volatilization-related ammonia and fossil-fuel nitrogen oxides emission sources, which are the major contributors to atmospheric nitrogen deposition in Mengshan area.

The allocation of annual growth in biomass to primary plant organs is a central theme in ecology due to its role in developing ecological theories and agricultural applications. Classic theories have significantly improved our understanding of biomass allocation patterns influenced by various factors. However, increasing contrasting observations cannot be explained by classic theories. Recently, transient dynamic theory can resolve the problem. Here, we provide empirical evidence describing transient variations of biomass allocated to stems for four crop species (i.e., corn, soybean, flax, and wheat) in single and mixed systems. We show that plant ontogeny and increasing intraspecific competition promote variations in stem mass fractions. However, variations in stem mass fractions are reduced under strong interspecific competition. Plants with large total biomass have relatively stable stem mass fractions. These findings provide empirical foundations for integrating transient dynamics into general theoretical frameworks of biomass allocation patterns and may stabilize agricultural crop yields.

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.

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.

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 analyzed 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.

Invasive alien species threaten global biodiversity and ecosystems. Understanding the context-dependency of invasion dynamics is crucial for uncovering the processes driving the establishment and spread of alien species. This study investigates how abiotic (soil characteristics) and biotic factors (resident vegetation diversity and similarity to the invader) affect the invasion success of Senecio inaequidens (South African ragwort) across high- and low-productivity habitats in Northern Italy. Our results revealed that abiotic and biotic factors affect S. inaequidens success. We found evidence of biotic resistance from resident plant communities, driven mainly by diversity and cover. However, a negative relationship between S. inaequidens performance and both phylogenetic and functional similarity to resident species was found, indicating better performance when growing with more similar species. We additionally observed stronger resistance in more nutrient-rich environments, highlighting the context-dependent nature of such relationships. Our results suggest that S. inaequidens is more susceptible to competition than adverse abiotic conditions, making it as a good colonizer rather than a strong competitor. These findings emphasize the complexity of invasion dynamics and the importance of considering both biotic and abiotic factors in developing management strategies for invaded ecosystems.

Compared to terrestrial plants whose diversity is more directly influenced by climate, aquatic plant diversity is considered to be more dependent on water environments. Therefore, it could be predicted that the phylogenetic relatedness of terrestrial plants is more susceptible to climate filtering than that of aquatic plants. We compiled a comprehensive distribution dataset of herbaceous angiosperms in China, including both terrestrial and aquatic species. We compared the phylogenetic relatedness and its environmental correlation of the two groups, using the standardized effect size of phylogenetic diversity (PD_ses) and the standardized effect size of mean phylogenetic distance (MPD_ses), which reflect shallow and deep evolutionary histories, respectively. We also use the deviation of PD_ses (ΔPD_ses) and MPD_ses (ΔMPD_ses) between terrestrial and aquatic plants to reflect differences in the phylogenetic relatedness between terrestrial and aquatic plants. Our results showed that the geographical patterns of PD_ses and MPD_ses between aquatic and terrestrial plants are roughly consistent. ΔPD_ses and ΔMPD_ses between terrestrial and aquatic plants vary across the geographical scale and environmental gradient. Environmental variables (current climate, historical climate change, and topography) explained more of the variation in PD_ses and MPD_ses of terrestrial plants than that of aquatic plants, with current climate explaining more of ΔPD_ses and ΔMPD_ses between terrestrial and aquatic plants. Our results reveal the differential impacts of large-scale environmental factors on the phylogenetic relatedness of terrestrial versus aquatic plant communities, providing a new perspective for understanding the ecological and evolutionary dynamics of these two distinct plant assemblages.

Bidens pilosa, a globally invasive Asteraceae plant, threatens both natural and agro-ecological habitats. Species distribution models (SDMs) are a valuable tool for predicting invasion potential, often exclusively based on climate variables. Here, we aimed to predict the current and future global distribution of B. pilosa by integrating climatic, human-induced and biodiversity factors, all of which are critical for accurate projections. Our more comprehensive results showed that climate conditions were the main driver of B. pilosa’s current distribution, with an expanded suitable area compared to previous studies, especially in eastern China and the Sichuan Basin. Incorporating human-induced factors significantly reduced predicted suitable areas, reflecting the species’ association with disturbed environments shaped by human activities. Biodiversity factors further refined habitat suitability, as areas with high phylogenetic richness identified as potential hotspots for invasion due to competitive or facilitative interactions. Future predictions, based on solely available climate data, suggested a high risk of habitat expansions in Asia, Europe, and North America. Niche dynamic analyses revealed that introduced populations occupied a distinct environmental niche space compared to native populations, due to adapting to altered climatic and anthropogenic conditions. This ecological niche divergence is likely driving the increased invasion risk in the introduced range. Our study underscores the complex interactions between climate conditions, biodiversity and human activity in shaping the spread of B. pilosa. SDMs integrating climatic, biotic variables and human influenced factors, together with updated occurrence data improves predictions of invasion spread and helps guiding targeted management.

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 (well-watered, CK; moderate drought, MD; severe drought, 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. S. 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.

This study used a method based on a spatial series in place of a temporal series and on the selection of T. ramosissima shrubs at the different developmental stages of coppice dunes as research subjects. It investigates the chlorophyll fluorescence characteristics and non-structural carbohydrates (NSC) of T. ramosissima on coppice dunes. The results indicated that, (1) T. ramosissima showed a significant increase in photosynthetic pigment content concomitant with a decrease in actual photochemical efficiency (Y_(II)) as coppice dune development progressed. Simultaneously, the reduction of the plastoquinone (PQ) pool intensified, the apparent electron transport rate (ETR) increased, and the quantum yield of regulated energy dissipation significantly increased. This 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 gradually decrease, leading to increased stress on T. ramosissima and a subsequent decrease in NSC content. This increased stress put T. ramosissima at risk of “carbon starvation,” resulting in a gradual decline in photosynthesis, biomass accumulation, and ultimately, death. (3) The correlations between various indicators of T. ramosissima were significant, with the highest degree of association and marked enhancement of synergistic effects in the growth and decline stages of coppice dunes. Comprehensive analysis revealed that high soil moisture content can help alleviate water stress, improve light energy use efficiency, and enhance the photosynthetic carbon assimilation process in T. ramosissima during coppice dune development.

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 a 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.

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. Consequently, predicting the future distribution and richness of these species in China holds substantial importance. Nevertheless, a thorough assessment of the responses of China’s Fagaceae to future climate change remains absent. This study presents the first national-scale assessment of the future distribution of over 200 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 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, providing potentially useful guidance for conservation planning of these species in China.

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.

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.

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 (CWM) 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.

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.

Interspecific plant-soil feedback (PSF)—the influence of soil conditioned by one plant species on another—are key to ecosystem processes but remain 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.

Interactions among roots and leaves are fundamental for plant growth and survival, yet it remains a knowledge gap in mangrove plants that experience saline stress distinct from most other vascular plants hereafter the non-mangroves. Here, we explored the coordination of above- and belowground trait relationships among mangrove species in tropical China and compared it with those of non-mangroves. Our resulted show that root stele, the water-conducting tissue, was coupled with leaf water use traits and tissues outside the stele (ToS), the carbon-consuming tissues in roots, was independent of leaf economics traits in non-mangroves. However, in mangroves, root stele is independent of leaf water use traits and root ToS is coupled with leaf economics traits. The contrasting root-leaf coordination between mangroves and non-mangroves potentially arises from the existence of leaf water storage tissues in mangroves and the universal allometric relationship between root stele and ToS in both plant groups. Our findings pave a new way for understanding of the ecology and vegetation dynamics of mangrove and non-mangrove plants under global environmental change.

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.

Phenology is one of the most reliable tools for understanding the effect of climate change on forests. Although there has been increasing research into the effect of climate on phenological activity, little is known about how phenological patterns for the same species may vary among environments, particularly for tropical species. Here we analysed the reproductive phenology of an important tropical rainforest tree species in northeastern Australia, Cardwellia sublimis, and compared the patterns among seven different sites. We also tested and compared the climate drivers of reproductive phenological activity among sites for this species. Degree of seasonality varied across sites with most sites presenting moderate - high seasonality. Flowering and fruiting peaked in different seasons at the different sites and we found flowering and fruiting phenology were often influenced by different climate drivers at the different sites. Where the climate drivers were the same, the magnitude and direction of the effect of the drivers differed among sites. Precipitation was the most common climate driver of flowering, being significant for all sites, while fruiting was predominantly influenced by temperature and solar radiation. Finally, we found evidence that relationships between climate drivers and phenological patterns were dependent on inter-site differences in climate and geography. Our results demonstrate that species may present varied phenological patterns and varied responses to climate drivers dependent on environmental conditions and site location. These results have important implications for modelling phenological patterns based on limited field information, as well as for understanding species vulnerability to climate change.

Elevational gradients provide a unique opportunity to study the plasticity of plant-pollinator interactions, which is crucial for understanding ecological and evolutionary processes in plant pollination systems. Species-specific dispersal across elevation gradients of tropical mountains is constrained by the different tolerance of individual species to abiotic factors. Consequently, the composition of plant and pollinator communities, such as their interactions, changes continuously. For example, previous studies have shown a bee-to-fly transition as elevation increases, or that at high elevations, bird-pollinated plants may be more effectively pollinated than closely related bee-pollinated species, highlighting an altitude-driven bee-to-bird transition. We used Hypericum revolutum (Hypericaceae) as model plant, to explore how the identity and activity of floral visitors change along an elevational gradient in the montane grasslands of Mount Cameroon. We observed flower visitors across four elevations during two seasons. Our study confirmed the predicted bee-to-fly transition with increasing elevation. Bird activity followed a hump-shaped pattern, peaking around 2,800 meters above sea level. Male Cinnyris reichenowi individuals, the main bird floral visitor, exhibited higher activity than females throughout the entire elevational gradient and across both study periods. The observed patterns suggest that plants may face evolutionary pressures to adapt to these shifting pollinator communities, potentially driving local adaptations and diversification within populations.

The carbon balance processes of plants in response to diurnal environmental changes are critical for their growth and survival. While sex-specific responses in photosynthesis to environmental stress have been observed in several dioecious plant species, the diurnal dynamics of carbon balance in male and female individuals remain unexplored. Here, we investigated the diurnal variations of photosynthetic rate (A), dark respiration rate (R_d), A/R_d, and the concentration, pool, and allocation of non-structural carbohydrates (NSC) of male and female mulberry (Morus alba) seedlings. Males exhibited the highest A at 09:00, while females had the highest A and R_d at 13:00. Male A was higher than female A at 09:00, whereas male R_d was lower than female R_d at 13:00. The A/R_d was higher in males than in females. The peak of NSC concentration in males was earlier than in females, and the NSC concentration and storage in the whole plant, leaves, and bark were generally higher in males than in females across most time points. The average NSC allocation followed the leaves > roots > bark ≈ trunk trend, but its dynamic changes over the daily cycle were more pronounced in females than in males. These findings suggest that carbon balance processes in mulberry seedlings exhibit sex-specific responses to diurnal changes, with females displaying greater sensitivity to these variations. This study is the first to explore such responses in woody plants and suggests that future carbon cycle models for terrestrial plants should incorporate plant sex.

Alpine meadows in Sanjiangyuan (SJY) National Park are experiencing degradation, and soil microbes play a critical role in maintaining the health and stability of these ecosystems. Soil microbes showed strong habitat specificity during meadow degradation, but we poorly understood the ecological assembly processes in soil microbial communities. This study explores the changes in ecological components across original and degraded patches of alpine meadows in SJY National Park. We examined vegetation-soil characteristics through field surveys, and soil microbial community structure by using high-throughput sequencing techniques. At the macro level, alpine meadows degradation increased vegetation species diversity, significantly reduced above-ground productivity, and made the soil more barren and alkaline. At the micro level, although the dominant phyla of soil microorganisms were similar in different degradation states of alpine meadows, degradation significantly increased the relative abundance of oligotrophic bacteria and decreased the relative abundance of dominant fungi. Additionally, microbial communities exhibited significant β-diversity. Degradation also led to an increase in microbial α-diversity, heightened microbial taxa competition, and a more complex microbial co-occurrence network. However, vegetation-soil variables explained only a small portion of the variation in soil microbes. Through the study of microbial ecological assembly processes, it was found that degradation enhanced the stochastic processes of soil microbial communities, and the changes in soil microbial communities were mainly driven by the variations inherent in the microbes themselves. These findings highlight the complex ecological interactions between above- and below-ground components, and emphasize the critical role of microbial community dynamics in ecosystem functions.

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 to be fully explored. Here, we compiled a dataset comprising 442 species-site combinations, spanning nearly all vegetation types in China, to address this knowledge gap. 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 non-woody species; however, there was no significant difference in LCC between evergreen and deciduous plants. LCC decreased with latitude and longitude but increased with 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 nitrogen 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 further research exploring the interplay between LCC, ecological functions, and macroevolutionary implications.

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. Our results demonstrated the difference in the latitudinal gradient patterns of fleshy and dry fruits and identified the major abiotic environmental factors that drove their distribution in large-scale spaces, demonstrating the biogeography of the fruit types of woody plants.

Invasive plant inputs alter soil microbial communities via chemical compounds in litter, root exudates, and leachate, impacting a range of soil processes, but precise effects are poorly understood. We examined Solidago canadensis, a common invasive species in China, and its litter effects on soil microbial communities under natural conditions. Experimental treatments included S. canadensis seedling density (1 and 2 plants/pot) and quantity of litter (10 and 20 g/pot), with control groups that contained 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 increased soil pH, organic matter (SOM), and 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 the invasive species, alongside shifts in dominant bacterial genera including Sphingomonas, Acidobacteriales, and Gemmatimonas. Rarer genera under the invasive treatment species, such as Candidatus, Rhodoplanes and Novosphingobium, correlated positively with soil TN, pH, and SOM. Collectively, our results demonstrate how the increased presence of allelochemicals from S. canadensis litter significantly impact soil properties and bacterial communities, and may therefore have implications for ecosystem dynamics.

The invasion of Spartina alterniflora (SA) has led to significant hydrogen sulfide (H₂S) production in coastal wetlands. The phytotoxic S^2- plays a critical role in elemental biogeochemistry and may contribute to the successful invasion of SA in areas contaminated with heavy metals. To explore how H₂S influences nutrient uptake and energy utilization in SA and the native Phragmites australis (PA) under cadmium (Cd) stress, and to uncover the mechanisms by which H₂S facilitates SA invasion, a hydroponic experiment was conducted. This experiment included three Cd concentrations (0, 1, and 2 mg Cd L^-1) and three H₂S treatments (inhibiting H₂S synthesis, simulating an external H₂S source, and an untreated control). Results revealed that H₂S plays a crucial role in balancing the uptake of Mg, Mn, Ca, and Zn in SA, mitigating Cd-induced damage to the photosynthetic system, and enhancing nutrient and energy accumulation under Cd stress. In contrast, H₂S was toxic to PA, increasing lipid peroxidation, inhibiting growth, and disrupting mineral uptake, particularly of Ca. This exacerbated the detrimental effects of Cd on the photosynthetic system and nutrient accumulation in PA. In summary, irrespective of Cd treatment, H₂S enhanced energy accumulation, mineral uptake, and growth in SA compared to PA. It potentially supported the ecological niche competition within the coastal wetlands during the invasion of SA into PA habitats. Consequently, inhibiting endogenous H₂S synthesis in SA may offer a potential strategy for controlling its invasion.

Plant root-associated fungal communities are pivotal for 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 utilized high-throughput sequencing, co-occurrence network analysis, and null models to perform an extensive examination of the diversity, composition, interaction patterns, and assembly mechanisms of the root-associated fungal communities of Mussaenda pubescens, a drought tolerant shrub that can thrive in stressful environments and which 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, play a significant role in fungal assembly. Furthermore, soil physicochemical properties, climatic conditions, and spatial variables also 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.

Floodplain wetlands have a significant 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, a high transpiration rate may reduce soil moisture, thereby improving the aeration of wetland soils and facilitating the oxidation of organic materials. Therefore, the impact of poplars on wetland carbon stocks is undetermined and remains unexplored. Here, we investigated the effects of poplar plantations on biomass carbon stocks (BCS) and soil organic carbon (SOC) stocks 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 stocks 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 it did not increase with stand age. The BCS was positively associated with soil bulk density, and the SOC stocks were negatively associated with soil sand content. Overall, our findings indicate that poplar plantations increase carbon stocks in the Dongting Lake wetlands. Nevertheless, the long-term effect of poplar plantation on carbon sequestration in floodplain wetlands should be further investigated.

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 focused on how 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 coefficients a and b for Cunninghamia lanceolata and Pinus forest in China. Results show that most of the allometric coefficients 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 coefficients) considerably improved the accuracy of tree height and biomass estimation. Compared to the basic model, the second approximation models significantly 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.