The mating systems and floral traits often among relatives of hermaphroditic plants can exhibit considerable diversity. This diversity can be influenced by the evolution of selfing and associated floral traits as a form of reproductive assurance (RA) when pollen limitation (PL) results from insufficient pollinator availability. To explore whether the degree of PL primarily drives differences in mating systems and floral traits, we conducted a comprehensive study involving two closely related species, Halenia elliptica and Halenia grandiflora, in three sympatric sites. We investigated floral characteristics, pollinator visitation, PL, autonomous selfing ability, RA and mating system in studied populations. Our findings show that H. elliptica produces smaller flowers and less nectar production than H. grandiflora, making it less attractive to pollinators. Compared with H. grandiflora, H. elliptica experienced more severe outcross pollen limitation (OPL), but compensates with a higher capacity for autonomous selfing, ensuring seed production under natural conditions. Moreover, significant differences in mating systems were detected between them, with H. elliptica exhibiting a higher selfing rate than H. grandiflora across all studied sympatric populations. These differences are also reflected in variations in herkogamy and dichogamy. Our study suggested that the degree of OPL impacts the divergence in mating systems and floral traits between sympatric closely related species, offering valuable insights into the evolution of plant mating systems and floral traits.

The decline in tree growth has become a global issue. It is critically important to explore the factors affecting tree growth under the background of global climate change to understand tree growth models. A database was established based on Robinia pseudoacacia growth and its driving factors on China’s Loess Plateau. Linear regression and three machine learning methods, including support vector machine, random forest (RF) and gradient boosting machine were used to develop R. pseudoacacia growth models considering forest age, density, climate factors and topographic factors. The root mean square deviation method was adopted to quantitatively assess the relationship between tree growth and soil properties. The average tree height of R. pseudoacacia on the Loess Plateau was 8.8 ± 0.1 m, the average diameter at breast height (DBH) was 10.4 ± 0.1 cm and the average crown diameter was 3.2 ± 0.1 m. The RF model was a fast and effective machine learning method for predicting R. pseudoacacia growth, which showed the best simulation capability and could account for 67% of tree height variability and 55% of DBH variability. Model importance indicated that forest age and stand density were the main factors predicting R. pseudoacacia growth, followed by climate factors. The trade-off between R. pseudoacacia growth and soil properties revealed that soil texture and soil pH were the primary determinants of R. pseudoacacia growth in this region. Our synthesis provides a good framework for sustainable forest management in vulnerable ecological areas under future climate change.

The intricate interplay among plant productivity and soil factors is a pivotal driver for sustaining the carbon sequestration capacity of coastal wetlands. Yet, it remains uncertain whether climate warming will reshape the cause-and-effect interactions between coastal plant productivity and soil factors. In this study, we combined a manipulative warming experiment with a convergent cross-mapping technique to quantify the causal relationships, which can be either unidirectional or bidirectional, between plants (gross primary productivity, GPP) and soil environment (e.g. soil temperature, moisture and salinity). Our findings revealed that warming amplified the interaction between GPP and soil salinity in the coastal wetland ecosystem. While soil temperature primarily drove this causal relationship in control plots, a more complex interaction emerged in warming plots: soil salinity not only directly influenced GPP but also indirectly affected it by altering soil temperature and moisture. Overall, warming increased the number of causal pathways linking GPP with soil environmental factors, such as the effect of soil salinity on GPP and the impacts of GPP on soil moisture. These findings provide experimental evidence of intensified plant–soil causality in coastal wetlands under climate warming.

Trade-offs have long been recognized as a crucial ecological strategy for plant species in response to environmental stresses and disturbances. However, it remains unclear whether trade-offs exist among different structures (or functions) of clonal plants in response to aeolian activities in sandy environments. We examined the growth (reproductive vs. vegetative), reproduction (sexual vs. asexual), and bud bank (tiller buds and rhizome buds, representing vertical and horizontal growth potential) characteristics of two dominant rhizomatous grasses (Psammochloa villosa and Phragmites australis) in the arid sand dunes of northwestern China. Our results showed that these two rhizomatous clonal species exhibited significant trade-offs in their adaptation strategies in response to changes in sand burial depth. Specifically, as sand burial depth increased, the clonal species tended to reduce their reproductive growth, sexual reproductive capacity, and horizontal growth potential, as evidenced by reductions in reproductive ramet number and proportion, panicles number, biomass, and their proportions, as well as rhizome bud number, biomass, and their proportions. Conversely, they increased vegetative growth, reproduction, and vertical growth potential, as evidenced by enhancements in vegetative ramet number and proportion, belowground bud number, biomass, and their proportions, and in tiller bud number, biomass, and their proportions. Our study underscores the importance of trade-offs in the adaptation strategies of rhizomatous clonal species in sandy environments where drought stress and aeolian disturbance coexist. Those trade-offs could ensure the population persistence and stability of pioneering psammophytes in sand dunes, which should be considered during sand-fixing and vegetation restoration efforts in arid sand dunes.

The ecologically fragile arid valleys in western China have low afforestation survival rates, and the lack of adaptable superior variety is key to restricting forestry production and ecological restoration in this region. The native poplar trees are important germplasm resources in this region, with a wide range of taxa, rich genetic variations, and great potential for breeding and utilization. Six clones of native poplars were used in a field trial to investigate variations in survival, growth and adaptation to arid-warm and arid-hot valleys. In the arid-hot valley, clone Y1-2 exhibited the highest survival rate and growth condition, surpassing other clones, while clones B7-4 and P3-6 demonstrated superior survival and growth performance in the arid-warm valley. Clone B7-4 displayed the highest soluble sugar content in leaves across both habitats. Superoxide dismutase and ascorbate peroxidase activities, along with malondialdehyde content in leaves, were higher in the arid-hot valley for all clones compared with the arid-warm valley. Long-term water use efficiency, as indicated by δ¹³C in leaves, was significantly higher for all clones in the arid-hot valley, particularly for H1-6, T3-2 and P3-6. Increases in upper epidermis thickness were observed in clones E1, B7-4 and P3-6, while Y1-2 exhibited a higher palisade parenchyma thickness (PT) in the arid-hot valley compared with the arid-warm valley. Vein densities were higher in leaves of clones E-1, B7-4, Y1-2 and P3-6 in both valleys compared with other clones, with B7-4 showing a significant increase in mean vein width in the arid-hot valley. In conclusion, the superior growth performance of clone B7-4 in the arid-warm valley may be attributed to its stronger osmotic adjustment and higher capacity to maintain water transportation through venation. The exceptional performance of clone Y1-2 in the arid-hot valley may be associated with its compact arrangement of PT, as well as its stronger capacity for hydraulic transport and antioxidant resistance in leaves.

Accurate estimation of vegetation biomass is a critical component for estimating terrestrial ecosystem carbon stocks. However, research on biomass estimation for herbaceous marshes remains limited. In this study, we collected 270 paired above-ground biomass (AGB) and trait data from reed marshes in Northeast China to estimate AGB, and 70 paired AGB and below-ground biomass (BGB) data from global literature to estimate BGB. The results showed that classifying reed marshes into saltwater and freshwater marshes greatly improved the model fit (R2 values of classified vs. overall models: >0.50 vs. >0.31 for AGB estimation and >0.50 vs. >0.10 for BGB estimation, respectively). A power-law allometric model using plant height as the sole predictor was optimal for AGB estimation, and the inclusion of plant density did not markedly enhance prediction accuracy. The power function also effectively described the relationship between AGB and BGB, with scaling exponents of 1.13 and 0.60 for saltwater and freshwater marshes, respectively. Our results indicate that saltwater and freshwater marsh classification is necessary for accurate wetland vegetation carbon estimation. These findings provide valuable insights into the prediction of carbon dynamics in wetland ecosystem and supports a better understanding of wetland carbon sequestration.

The significance of microbes for ecosystem functioning is well known; however, within a single system, the relative contributions of keystone and rare taxa to soil microbial functions are less well quantified, as are their shared or unique responses to abiotic conditions. Furthermore, their associations with tree community composition in natural forest ecosystems are not well understood. In this study, a total of 1287 soil samples were collected from a 20-ha subtropical forest plot and analyzed using high-throughput sequencing. Based on co-occurrence network analyses, we conducted a comparison of the associations between keystone and rare taxa with the structure, functions and stability of soil microbial communities. Additionally, we examined their associations with tree community composition. Results showed that keystone taxa made a significantly greater contribution than rare taxa in all comparisons of microbial functions and stability. Keystone taxa had direct effects on microbial community structure and also mediated indirect effects of abiotic conditions. Neither effect was evident for rare taxa. The importance of keystone taxa also extended to aboveground composition, where tree community composition was more closely associated with keystone taxa than with rare taxa. While it may still be premature to establish causality, our study represents one of the initial attempts to compare the relative importance of keystone and rare microbial taxa in forest soils. These findings offer the potential to improve natural forest ecosystem functioning and tree diversity through the manipulation of a small number of keystone soil microbial taxa, as has been demonstrated in agroecosystems.

Plant crown can affect the seed dispersal process. Clarifying the influence of plant crown type on seed dispersal kernel is important for predicting species distribution. However, the effects of different plant crown types on seed dispersal have rarely been tested. To address this, we conducted wind tunnel experiments to investigate the average seed dispersal distance, range, kurtosis and skewness of 29 species with varying diaspore traits (e.g., appendage type, mass, projected area, shape index, wing loading and terminal velocity) under 3 wind speeds (2, 4 and 6 m s⁻¹). We examined seeds passing through different crown types, classified based on crown size, branch density, and the presence or absence of leaves. We fitted functions to the seed dispersal distance and found that the Gaussian function provided the best fit. Our results showed that plant crown type had significant effects on dispersal kurtosis and skewness but not on the average dispersal distance or range under low wind speed conditions. Specifically, crown width and branch density influenced dispersal kurtosis, while the presence of leaves affected both kurtosis and skewness. Increasing wind speed reduced the influence of plant crowns on dispersal kurtosis and skewness. Although plant crowns did not significantly affect average seed dispersal distance, they altered the shape of the seed dispersal kernel. Consequently, while the dispersal range of seeds through different crowns remained relatively invariant, the density of dispersal varied significantly. These findings provide valuable insights into plant metapopulation dynamics and highlight the importance of considering crown architecture in seed dispersal studies.

Climate change has significantly altered the carbon and water cycles of terrestrial ecosystems. Climate change and the extended vegetation growing season enhanced ecosystem gross primary production (GPP). However, the relative contributions of climate drivers and vegetation phenology to GPP remain unclear. Based on satellite-derived vegetation phenology and GPP datasets from 1982 to 2018, we investigated the spatiotemporal patterns of GPP and its drivers in the Jinsha River watershed. We found that the growing season GPP significantly increased from 1982 to 2018, which was primarily attributed to changes in the growing season length (GSL) and temperature. The effect of GSL on GPP was the highest (r = 0.34), with its effect being larger than that of temperature, precipitation and radiation in 41% of the watershed. Importantly, the area where GPP was predominantly influenced by GSL increased by 12% in grid cells during the period of 2001–2018 compared with 1982–2000, indicating that GSL was playing an increasingly important role in driving GPP. Our findings highlight the dynamic responses of GPP to climate change and the associated phenological variations, which are crucial for improving the understanding of the terrestrial carbon balance.

The spatial pattern of phenology reflects long-term plant adaptation to local environments, yet the drivers of these patterns remain poorly understood. Using satellite data from 2001 to 2018, this study employed the normalized difference vegetation index for vegetation structural greenness and solar-induced chlorophyll fluorescence for vegetation functional photosynthesis to analyze spring phenology on the Qinghai-Tibetan Plateau (hereafter, QTP). A machine learning method, Boosted Regression Trees (BRT), was applied to evaluate the contributions of 19 abiotic and biotic factors to the spring phenology. The results showed that both the spring leaf phenology (SOS_NDVI) and photosynthesis phenology (SOS_CISF) exhibited a delayed trend decreasing from east to west across the QTP. BRT analysis demonstrated shortwave radiation or/and elevation as key drivers, with higher radiation or elevation associated with more delayed spring phenology spatially, likely due to the constraints of extreme radiation and elevations on spring phenology. Furthermore, we also noted that plants were acclimated to strong radiation to some extent with increasing elevation, namely declined negative effect of radiation/elevation on spring phenology. This acclimation likely enhances plant fitness in the harsh environments of the QTP. Our study provides novel insights into plant phenology on the QTP and highlights the importance of integrating spatial and temporal analysis to improve the localization of phenology models.

Precipitation significantly influences the composition and structure of grassland ecosystems, particularly in arid desert steppes. Stipa breviflora, as a keystone species, plays a crucial role in maintaining the stability of the desert steppe. However, the response of S. breviflora’s succession strategy to changes in precipitation within the community remains uncertain. Since 2016, this research was conducted in a desert steppe in Inner Mongolia, China, involving control precipitation (PCK), and increases of 50% (P50) and 100% (P100) in natural precipitation. We measured biomass, height and canopy cover, calculated the importance value (IV) by species, and assessed the photosynthetic parameters and leaf elemental content of S. breviflora in 2021 and 2022. Results showed that the increase of precipitation significantly reduced the IV of S. breviflora. The net photosynthetic rate, transpiration rate, stomatal conductance, aboveground biomass carbon content and aboveground biomass nitrogen of S. breviflora leaves grew considerably in experimental plots receiving more precipitation, while δ¹³C value of leaves decreased significantly. Linear regression analysis and structural equation model showed that although the increase of precipitation improved the adaptability of S. breviflora functional traits and increased its IV, a higher transpiration rate significantly contributed to the decrease in its IV. Consequently, our research reveals the succession strategy of S. breviflora and provides a theoretical basis for studying the response mechanisms of desert steppe plant communities to climate change.

Atmospheric carbon dioxide (CO₂) concentrations have been increasing dramatically due to human activities and land use changes, and the CO₂ fertilization effect significantly increases global net primary productivity. However, whether the decomposition of surplus litter input on the soil surface is facilitated by elevated CO₂ (eCO₂) across a broad range of terrestrial ecosystems is not fully understood. We compiled 227, 85 and 131 paired observations (with and without eCO₂) for litter mass loss, carbon (C) and nitrogen (N) release, respectively, during litter decomposition to assess the fate of decomposing litter and C and N release under eCO₂ across terrestrial ecosystems. Litter mass loss was decreased by 4.5%, and C and N release were significantly reduced by 6.7% and 3.4%, respectively, under eCO₂. This eCO₂ effect on litter mass loss was greater in forests (decreased by 7.2%) than in croplands and grasslands. In forests, eCO₂ had a greater effect on the decomposition rate of broadleaved than coniferous litter, and root litter was more sensitive than leaf and stem litter. Changes in litter lignin concentration and edaphic factors under eCO₂ contributed to these differences in litter decomposition. Greater decreases in litter mass loss and C and N release were found after longer time (6–12 months) than short-term (less than 6 months) CO₂ enrichment. A possible consequence is that more litter accumulates on the soil surface without being decomposed due to eCO₂ in terrestrial ecosystems over longer time periods, resulting in a negative loop in biogeochemical cycles with increasing atmospheric CO₂ concentration.

Closely related and co-distributed species usually share a common phylogeographic history, but it remains unclear whether ecologically interacting species can respond synchronously to historical climate changes. Here, we focused on a fig–pollinator mutualism comprising Ficus pumila var. pumila and its obligate pollinators (morphospecies Wiebesia pumilae), and collected samples across most of their distribution ranges. We employed cytoplasmic DNA sequences and nuclear microsatellite loci to reveal the species composition within the pollinators and to test whether the two mutualists exhibited similar postglacial phylogeographic patterns. We identified three cryptic pollinator species, with two dominant cryptic species exhibiting parapatric distributions in the northern and southern parts of the plant’s range, respectively. Similar current spatial genetic structures were detected in the two dominant cryptic pollinator species and the host plant, with both showing eastern and western genetic clusters. Moreover, evidence for postglacial expansion was found for all three species, and their potential refugia during the Last Glacial Maximum were located in the eastern and western parts of their distribution ranges. These results suggest synchronous responses to historical climate changes. Our study demonstrates congruent phylogeographic patterns between obligate mutualists and highlights the role of biogeographic factors in shaping the current biodiversity across trophic levels.

Peatlands store one-third of the Earth’s carbon. Climate warming-induced peatlands vegetation shifted from Sphagnum to shrub, however, it is controversial whether this change leads to increased carbon losses. Through sequencing of the rhizosphere microbiome (vertically), measuring peat properties (vertically), a 35-day incubation experiment and a 35-day cross-inoculation experiment (only the upper layer), we investigated the ecosystem functions and the role of microbial communities and substrates in influencing the ecosystem functions of Sphagnum- and shrub-dominated peatlands in three locations in south China. The carbon dioxide (CO₂) emission from shrub-dominated peatlands was significantly lower than that from Sphagnum-dominated peatlands. The slow-growing fungi: Archaeorhizomyces, Hyphodiscus and Acidobacteria: Bryobacter, Occallatibacter were identified as keystone taxa in shrub-dominated peatlands, which mainly explained the effects of shrub microbial communities on CO₂ emission. The recalcitrant carbon content was the key substrate associated with CO₂ emission and the community composition of the plant rhizosphere microbiome. Furthermore, microbes fixed carbon in shrub-dominated peatlands was significantly higher than in Sphagnum-dominated peatlands, as the CO₂ emission reversed between Sphagnum- and shrub-dominated peatlands after soil sterilization. Overall, the relative abundance of keystone microbial taxa and nutrient levels decreased with peatland depth. Our study provided new evidence that climate change-induced peatland vegetation shift from Sphagnum to shrub leads to a higher accumulation of recalcitrant carbon, and does not deteriorate ecosystem functions. This study has implications for predicting the future influence of climate change on peatland ecosystems.

Warming has been consistently observed to reduce soil carbon (C) storage by accelerating the decomposition of soil organic matter. While different soil C fraction may respond differentially to warming, microbial necromass has been considered as an important contributor to the persistent soil C pool. However, the mechanisms by which warming regulates microbial necromass formation and its potential contribution to new soil organic carbon (SOC) fractions remain poorly understood. In this study, we examined the effects of elevated temperature on newly formed amino sugar C (an indicator of fungal and bacterial-derived microbial necromass C) and its allocation in particulate organic matter (POM) and mineral-associated organic matter (MAOM) fractions in alpine soils of Southwest China, based on a 37-day incubation experiment at 15 °C and 25 °C by adding ¹³C labeled glucose and oxalic acid. The results showed that warming significantly reduced the formation of new SOC by lowering the incorporation of new C into both POM and MAOM fractions. Glucose addition was more effective than oxalic acid in promoting new SOC formation, regardless of temperature. Warming also significantly decreased the new microbial necromass in both soil fractions with more bacterial necromass associated with mineral particles, which was primarily attributed to the higher abundance of bacterial community. In addition, glucose addition significantly promoted contribution of the fungal necromass to newly formed SOC. Overall, this study reveals that warming significantly alters the allocation of newly formed SOC and microbial necromass, highlighting the differential microbial responses in soil C sequestration. These findings have important implications for predicting and managing soil C stocks in forest ecosystems under climate change.

Alpine meadows of the Qinghai-Tibetan Plateau (QTP) are experiencing severe degradation due to intensified human activity and climate changes. However, there has been little attention paid to the effects of different grazing practices on the soil hydrological properties of alpine meadows. In this study, three grazing practices were established in an alpine Kobresia meadow: free grazing, reduced grazing and grazing exclusion. We found that the 0–10 cm soil water retention capacity (SWR) and plant available water content (AWC) in grazing exclusion treatment were higher than that in reduced or free grazing treatments, whereas the 20–40 cm SWR and AWC display the opposite pattern. The AWC and SWR variations were closely related to soil properties, and the redundancy analysis showed that SWR and AWC were positive related to soil organic matter (SOM), total porosity (TP) and capillary porosity (CP), but were negative correlated with soil bulk density (BD), clay and silt content. Structural equation modeling found that SOM was identified as the most important factor affecting SWR, and CP was the key factor influencing AWC. Therefore, the higher 0–10 cm SWR and AWC in grazing exclusion treatment may be attributed to its higher SOM and CP, respectively. Furthermore, root biomass can affect SWR and AWC through altering BD and SOM. Our study suggests that the response of soil hydrological properties to grazing practices was different, grazing exclusion only increase topsoil water retention capacity but not favor deep soil water retention capacity.

The field of ecology has been greatly enhanced by the integration of computational tools and statistical methods, with the programming language R emerging as a pivotal and flexible tool for ecological research. As ecological studies accelerate, understanding the prevalent trends and specific usage patterns of R in recent research is crucial. This study investigated the use of R and its packages in 125 494 scholarly articles published in 40 ecology journals from 2008 to 2023. A total of 52 658 articles (42%) designated R as their principal analytical tool, demonstrating a steady linear growth in its utilization from 10.3% in 2008 to 66.9% in 2023. Twelve R packages, including ‘lme4’, ‘vegan’, ‘nlme’, ‘MuMIn’, ‘ape’, ‘ggplot2’, ‘car’, ‘mgcv’, ‘MASS’, ‘raster’, ‘multcomp’ and ‘lmerTest’, each played a pivotal role in contributing to more than 1000 scholarly articles. The highest usage rate of the 'lme4' package indicates that mixed-effect models have a particularly important role in ecological research, and the application of these models has helped ecologists solve many important scientific problems. Journal-specific package preferences aligned with their scientific domains, while the rise in the average number of R packages per article indicates a trend towards more complex and diverse analytical methods in ecology. Our findings reveal a reciprocal relationship between the development of R and ecological research, underscoring the need for collaboration among quantitative ecologists, R developers and ecologists to further advance both the language and the field. Such collaboration will not only enhance the functionality and versatility of R but also provide robust technical support for the continued progress of ecological research.

Wood density indicates important plant functions and plays a key role in carbon cycling of forest ecosystems by affecting wood decomposition. However, how wood density varies globally and how it evolved through the evolutionary history of angiosperms remain unclear. Here, by integrating data of wood density, phylogeny, and distributions for angiosperms worldwide, we estimated global spatiotemporal patterns of wood density and their relationships with modern climate and paleoclimate. We found that mean wood density decreased with latitude in the northern hemisphere but increased with latitude in the southern hemisphere. The interspecific wood density variation within each geographic unit did not show clear latitudinal gradients. Temperature was the best predictor of the global geographic pattern in mean wood density, while the geographic variation in mean wood density across high-temperature regions could be explained by geographic variation in precipitation and precipitation seasonality. Since the Cenozoic (66 million years ago (Mya)), wood density increased first (until 20 Mya) and then decreased. In general, the Cenozoic wood density was positively correlated with paleotemperature and negatively correlated with paleoprecipitation, especially during more arid periods. Interestingly, the evolutionary trends of wood density on different continents differed, which corresponded to the divergence in wood density patterns and their relationships with modern climate on different continents. Our results highlight the dominant effect of environmental temperature on global variation in angiosperm wood density with an additional strong effect of precipitation seasonality. Our study also demonstrates the critical role of aridity and biogeographic idiosyncrasies in driving angiosperm wood density evolution.

Leaf functional traits reveal the ecological strategies of plants and affect growth and distribution. Variation in leaf traits was usually documented across species in terrestrial ecosystems, studying in wetlands can advance the understanding about leaf trait variation along environmental gradients. Intraspecific study contributes to explore trait variation and underlying mechanism. Marine coastal wetlands have become hot spots for studying trait variation. Invasive Spartina alterniflora distributed along China’s coastline, is an ideal species for studying leaf traits variation. We determined geographical variation and abiotic drivers in six leaf functional traits, and explored the roles of phenotypic plasticity and genetic differentiation through a 2-year common garden experiment. We detected relationships between leaf traits and growth performance in field and common garden. All leaf traits exhibited significant geographical variation, which were affected by both climatic and sedimentary variables. Common garden experiment exhibited the trait-dependent response, different leaf traits showed various degrees of plastic response or genetic differentiation. Variation in leaf size, leaf thickness, and specific leaf area displayed genetic differentiation, while variation in leaf density and leaf dry matter content exhibited plastic response. Leaf size and thickness positively correlated with growth performance in field and common garden. Our study advances the understanding about leaf trait variation in the terrestrial ecosystems. Multiple abiotic variables shape the latitudinal patterns in leaf traits. Resource acquisition at high latitudes in the northern hemisphere contributes to great growth performance of S. alterniflora, which might promote expansion northward, whereas the resource conservation at low latitudes might hinder expansion southward.

Soil microorganisms play a crucial role in alpine grassland ecosystem as indicators of environmental change. Rest-grazing in spring has been shown to effectively curb grassland degradation, and while the effects on plants and soil have been widely studied, the response of soil microbial communities and the underlying driving factors remain unclear. In this study, two types of winter-spring pastures, steppe meadow (StM) and swamp meadow (SwM), were conducted for rest-grazing and grazing in spring, and vegetation community characteristics, soil properties and microbial community composition were measured to investigate the response of soil microbial communities to rest-grazing and its mechanisms. The results showed that rest-grazing in spring significantly increased above-ground biomass and soil organic carbon in alpine grasslands. In the steppe meadow, microbial groups were lower in the first year of rest-grazing compared to grazing but higher in the second year. In the swamp meadow, microbial groups and the ratio of Gram-positive to Gram-negative bacteria were higher under rest-grazing than under grazing. Stress indices in both grassland types were lower under rest-grazing than under grazing. Fungi showed an increasing trend with above-ground biomass (P < 0.05), while total PLFAs, bacteria, and actinomycetes increased with below-ground biomass (P < 0.05). Variance partitioning analysis (VPA) revealed that the combination of soil and vegetation properties explained 40.87% of the variation in the soil microbial community. Redundancy analysis (RDA) indicated that species diversity (Simpson index), vegetation coverage, soil total phosphorus, and bulk density were significant influencing factors, with species diversity explaining the largest proportion of variation (60%). In summary, rest-grazing in spring can beneficially affect the soil microbial community by improving plant diversity and restoring soil properties in alpine grasslands.

To explore the adaptive strategies of the clonal plant Phragmites australis in heterogeneous salt habitats, we conducted a pot control experiment with severing, salt heterogeneity and competition treatment using dominant plants from the Yellow River Delta, including P. australis and Suaeda salsa. This study assessed the effects of salt heterogeneity, clonal integration and interspecific competition on the morphological and physiological traits of P. australis. The results showed that clonal integration significantly promoted root system growth and underground biomass accumulation of P. australis. Competition significantly reduced plant height, tiller number, leaf number, leaf length and internode length, inhibiting above- and underground biomass accumulation. Under the heterogeneous salt treatment, clonal integration significantly promoted only the rhizome biomass of P. australis. The S. salsa competition treatment significantly lowered the chlorophyll contents, net photosynthetic rate, stomatal conductance and transpiration rate of P. australis. Nevertheless, leaf length and width were maintained, potentially to minimize photoinhibition. Competition significantly reduced K⁺ contents in P. australis fine roots and rhizomes and Na⁺ contents in fine roots. The Na⁺ content of fine roots was significantly affected by competition, salt heterogeneity, severing treatment and the interaction between competition and severing treatment. In conclusion, competition significantly inhibited the growth, photosynthesis and ion content accumulation of P. australis. Meanwhile, clonal integration promoted root growth, especially under heterogeneous salt conditions. Hence, this research provided a significant and deeper understanding of the ecological adaptive responses of clonal plants in coastal heterogeneous habitats.

Understanding how phytoplankton adapt to elevated CO₂ and/or warming through long-term genotypic changes is critical for predicting future phytoplankton distribution and community structure. In this study, we conducted a 4.5-year experimental evolution with the model marine diatom Phaeodactylum tricornutum Bohlin under four environmental conditions: ambient (control), elevated CO₂, warming and combined elevated CO₂ + warming. Following this long-term adaptation, we exposed the populations to a broad CO₂ gradient in a short-term (7-day) experiment to assess their multi-trait responses. Our results demonstrate that P. tricornutum Bohlin populations adapted to different environmental regimes exhibit significant multi-trait variation across CO₂ gradients. Notably, the variability driven by long-term adaptation exceeded that induced by short-term CO₂ changes. Furthermore, both long-term adaptation and short-term CO₂ exposure altered trait co-variations, highlighting the complex interplay between environmental history and immediate conditions. This study emphasizes the importance of assessing long-term genetic changes in marine phytoplankton under global change, as short-term experiments alone may underestimate their adaptive potential and the broader implications for marine ecosystems under future climate scenarios.