Vegetation green-up is occurring earlier due to climate warming across the Northern Hemisphere, with substantial infuences on ecosystems. However, it is unclear whether temperature responses differ among various green-up stages. Using high-temporal-resolution satellite data of vegetation greenness and averaging over northern vegetation (30–75° N), we found the negative interannual partial correlation between the middle green-up stage timing (50% greenness increase in spring–summer) and temperature (R_P = −0.73) was stronger than those for the onset (15% increase, R_P = −0.65) and end (90% increase, R_P = −0.52) of green-up during 2000–2022. Spatially, at high latitudes, the middle green-up stage showed stronger temperature responses than the onset, associated with greater low-temperature constraints and stronger control of snowmelt on green-up onset as well as greater spring frost risk. At middle latitudes, correlations with temperature were similar between the onset and middle stages of green-up, except for grasslands of the Mongolian Plateau and interior western USA, where correlations with temperature were weaker for the middle stage due to water limitation. In contrast, the end of the green-up showed weaker temperature responses than the middle due to insuffcient water and high climatic temperature during the end of the green-up in most of the study region, except for cold regions in the interior western USA, western Russia and the Tibetan Plateau, where temperature was still a main driver during end of green-up. Our fndings underscore the differences in temperature responses among green-up stages, which alters the temporal alignment between plants and environmental resources.

Phylosymbiosis, the congruence of microbiome composition with host phylogeny, is a valuable framework for investigating plant–microbe associations and their evolutionary ecology. This review assesses the prevalence of phylosymbiosis across the plant kingdom, elucidates the fundamental ecological and evolutionary processes contributing to its occurrence based on previous research and explores commonly used methods for identifying phylosymbiosis. We find that the presence of phylosymbiosis may be influenced by both phylogenetic distance and the taxonomic level at which host plants are examined, with the strength of associations potentially decreasing as the taxonomic scale becomes finer. Notably, the endophytic microbiome exhibits a stronger phylosymbiosis signal compared with the epiphytic or rhizosphere-associated microbiomes. Microorganisms such as fungi and bacteria can yield highly variable evidence for phylosymbiosis due to differences in colonization, transmission or functional characteristics. We also outline how the four community assembly processes (dispersal, selection, diversification and drift) contribute to the establishment and maintenance of host–microbe phylosymbiosis. Furthermore, we highlight the diversity of methods employed to detect phylosymbiosis, which involves three key processes: constructing host phylogenies, assessing microbial data and statistically evaluating the correlation between host phylogeny and microbial composition. Remarkably different methodologies across studies make comparisons between findings challenging. To advance our understanding, future research is expected to explore phylosymbiosis at lower taxonomic levels and investigate different microbial communities coexisting synergistically within the same host. Understanding the relative importance of community assembly processes in driving phylosymbiosis will be critical for gaining deeper insights into the ecology and evolution of host–microbe interactions.

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

Invasive plant species pose signifcant ecological and economic threats due to their establishment and dominance in non-native ranges. Previous studies have yielded mixed results regarding the plants’ adaptive mechanisms for thriving in new environments, and particularly, little is known about how the phenotypic plasticity of growth and defense-related traits may facilitate plant invasion. This study addressed these uncertainties by employing the aggressive weed Reynoutria japonica as a study model. We examined the differences in growth, defenserelated traits and biomass allocation between R. japonica populations from native and introduced ranges grown in two common gardens with distinct climate conditions. Our results demonstrated that while the introduced populations did not exhibit increases in height and total dry mass, nor reductions in leaf defense levels, their investment in leaf production was signifcantly higher compared to the native populations. Additionally, introduced populations displayed greater phenotypic plasticity in clonal ramet but less phenotypic plasticity in biomass production than native populations across varying environments. These fndings highlight the roles of phenotypic plasticity and specifc trait adaptations, such as clonality, in the successful invasion of R. japonica. This study has important implications for managing invasive plant species under changing environmental conditions.

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 survival and reproduction of plants in a particular region are closely related to the local ecological niche. The use of species distribution models based on the ecological niche concept to predict potential distributions can effectively guide the protection of endangered plants, prevention and control of invasive plants, and plant introduction and ex-situ conservation. However, traditional methods and processes for predicting potential distributions of plants are tedious and complex, requiring the collection and processing of large amounts of data and the manual operation of multiple tools. Therefore, it is difficult to achieve large-scale prediction of the potential distributions of plants. To address these limitations, by collecting and organizing a large amount of basic data, occurrence records, and environmental data and integrating species distribution models and mapping techniques, a workflow to automatically predict the potential distributions of Chinese plants was established, thus the innovative work of predicting the potential distributions of 32 000 species of plants in China was completed. Furthermore, an online platform for predicting plant distributions in China based on visualization technology was developed, providing a basis for sharing the prediction results across a wide range of scientists and technologists. Users can quickly access information about the potential distributions of plants in China, providing a reference for the collection, preservation, and protection of plant resources. In addition, users can quickly predict the potential distribution of a certain plant in a certain region across China according to specific needs, thus providing technical support for biodiversity conservation.

Floral syndrome is one of the key components of plant pollination syndromes, affecting variety of evolutionary and ecological processes in angiosperms. The evolutionary transition from self-incompatible heterostyly to self-compatible homostyly occurred repeatedly in angiosperm families. Although the evolution of heterostyly and homostyly has been deeply studied, our understanding on their differences in ecological strategies is still lacking. In this work, using the floral syndrome and distributions of the Primula in China we compared the spatial pattern of floral syndrome frequency and its climatic determinants. Our results reveal that distylous and homostylous Primula have similar primary centers of species diversity in southwest China, while distylous species have larger range size than homostylous ones. Temperature seasonality is the dominant climate factor of these geographic patterns, but its effect is much stronger in distylous than in homostylous Primula. Distylous species have larger flower size and number, and fruit size than homostylous ones. Climate, especially temperature seasonality mainly influenced species range size via its effects on floral syndrome. Our study suggests that homostyly is likely derived from heterostylous ancestors in similar geographical context, and larger reproductive investment in floral phenotype may provide compensatory mechanisms for obligate out-breeding heterostyly. Future investigations regarding the evolutionary history and tolerance or resistance to environmental change between distyly and homostyly may greatly advance our understanding of their spatial pattern and adaptative differences.

Genotype diversity is an important component of biodiversity, and has potential positive effects on ecological processes, such as primary productivity. Recent studies suggest that crop cultivar mixtures can improve biomass or yield, however, the generality and size of this effect, as well as the underlying mechanisms are unclear. We selected nine genotypes of spring wheat (Triticum aestivum L.), and tested monocultures (of one genotype) and mixtures (of nine genotypes) to verify whether the positive effect of genotype diversity could be observed. Meanwhile, we arranged two planting environments, real field and artificial pot conditions, to clarify how the effect of genotype diversity depends on environmental conditions. Results showed that the effect of genotype diversity was highly dependent on the planting environment; compared with monocultures, mixtures significantly improved aboveground biomass and grain yield of spring wheat in pots by 14.5% and 8.2%, respectively, while no improvements were observed in the field. In pots, positive complementarity effects dominated the positive net effect by offsetting negative sampling effects, while no significant diversity effects were observed in the field. The greater trait differences in pots were more favorable for resource-use complementarity and reducing intraspecific competition, which might be the main reason for the large positive complementary effect in pots. Our results suggest that increasing the biomass and grain yield of spring wheat by providing genotypic diversity was supported by specific ecological mechanisms and could be achievable. However, environmental conditions in actual production may limit its efficacy, and more extensive field experiments are thus needed to verify the effectiveness of genotype diversity.

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.

Despite much recent progress, our understanding of plant phenology response to climate change remains incomplete. In particular, how and to what extent climate warming affects the vegetative and reproductive phenology of different plant functional groups in northern grassland ecosystems remains largely unexplored. Here, we compiled data of 1758 observations from 25 individual studies and carried out a meta-analysis of plant phenology in relation to temperature changes across a range of plant species and functional groups in northern China. We show that climate warming tended to extend the duration of reproductive phenology while having no effect on the duration of vegetative phenology. We also identified specific temperature sensitivities for different phenological stages: 1.73 days °C⁻¹ for budding, −3.38 days °C⁻¹ for leaf spreading and 0.56 days °C⁻¹ for yellow withered stage, respectively. Notably, warming resulted in earlier leaf spreading in shrubs and semi-shrubs, but caused a delay in the budding time of sedges. In terms of reproductive phenology, temperature sensitivity was −1.73 days °C⁻¹ for flowering time, −2.53 days °C⁻¹ for fruit ripening and −0.11 days °C⁻¹ for fruit shedding, respectively. Warming advanced the flowering and fruit repining time of all functional groups except for legumes. Our results indicate that elevated temperatures advanced reproductive phenology and extended its duration in northern grasslands, while showing no impact on vegetative phenology. Our findings demonstrate the differential responses of different functional groups to warming, highlighting the diverse growth strategies and adaptation of grassland plants in a warming world.

Legumes play critical roles in agroecosystems by modulating nitrogen-fixing microorganisms to enhance soil fertility and promote crop productivity. Current research on the effects of legumes predominantly focuses on surface soil, lacking a comprehensive analysis of their overall impact across multiple soil layers and an in-depth understanding of associated microbial mechanisms. Here, the community structure of soil nitrogen-fixing microorganisms in three soil layers (0–20 cm, 20–50 cm and 50–100 cm) under legume and non-legume cultivation was investigated through metagenomic sequencing. We found that only in topsoil (0–20 cm) legume treatment exhibited a significantly higher relative abundance of nitrogen-fixing genes than non-legume treatment. Under legume cultivation, the relative abundance of nitrogen-fixing genes was significantly higher in the topsoil layer than in deeper layers, whereas non-legume treatment displayed an inverse depth-dependent pattern. Combining soil physicochemical properties, the relative abundance of nitrogen-fixing genes correlated significantly with soil moisture, total carbon (TC), and dissolved organic carbon (DOC) content. Both TC and DOC were identified as key drivers of these genes. Subsequently, a similar depth-dependent pattern within the relative abundance of soil carbon degradation genes was found in response to the cultivation of both crops. The relative abundances of soil carbon degradation genes were negatively correlated with nitrogen-fixing genes under legume treatment individually, distinct from non-legume treatment. Our findings highlight the depth-dependent impact of legumes on nitrogen fixation and the critical interaction between soil carbon degradation and nitrogen fixation, providing insights into carbon management in legume cultivation practices to enhance nitrogen fixation in future agriculture.

Soil respiration is an important pathway of carbon release from the terrestrial biosphere to the atmosphere, which plays a key role in ecosystem carbon cycling. However, the response and mechanism of soil respiration to nitrogen and phosphorus addition in legume plants are still unclear. Here, a pot experiment planted with soybean (Glycine max (L.) Merr.) was conducted to investigate the effects of nitrogen (N) and phosphorus (P) addition on soil respiration. Four treatments were designed: control, N addition, P addition, and both N and P addition. Soil respiration was measured twice a month from June to September in 2022. Our results showed that nutrient addition treatments presented significantly negative effects on soil respiration. In particular, nitrogen addition not only directly affected soil respiration, but also indirectly impacted soil respiration by altering soil nitrate nitrogen content. Elevated soil nitrate nitrogen content could inhibit soybean root nodule number and reduce biomass allocation to roots, thereby decreasing soil respiration. Furthermore, phosphorus addition and nitrogen–phosphorus co-addition strongly inhibited soybean nodulation by changing soil pH value, thus inhibiting soil respiration of soybean. The findings provide baseline information for optimizing nutrient management in legume crops.

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.

As a crucial strategy for sustainable agricultural production, green manure–crop rotation can regulate soil nutrient cycling and decrease the reliance on nitrogen fertilizers. However, we still lack a comprehensive understanding of the changes in soil eco-enzyme activities, microbial metabolism and nutrient limitations caused by leguminous green manure–crop rotation. Here, we conducted field experiments of leguminous green manure–crop rotation across China to analyze soil extracellular enzyme activities, specifically β-glucosidase (BG), N-acetyl-β-d-glucosaminidase (NAG), leucine aminopeptidase (LAP) and acid phosphatase (AP). The study revealed that long-term green manure–crop rotation increased carbon and nitrogen accumulation in farmland, with a significant average increase of 20.1% and 36.4% in BG, AP enzyme activities in topsoil, while showing a decrease in ln(NAG + LAP):ln(AP) ratios. The ratios of ln(BG):ln(NAG + LAP) and ln(NAG + LAP):ln(AP) in soil across various regions were typically below 1:1, indicating that soil microbial activity is more constrained by nitrogen and phosphorus nutrients rather than by carbon. Precipitation, temperature, soil total carbon (TC) and total nitrogen (TN) were identified as key environmental factors for extracellular enzyme activities and stoichiometric ratios. Our study highlights that the green manure–crop rotation alleviates nitrogen limitation while enhancing phosphorus limitation, and is closely related to the accumulation of TC and TN in the soil.

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

Understanding the physiological mechanisms that trees employ to cope with drought-induced mortality is crucial for predicting their responses to a changing climate. Salix species exhibit distinct habit distributions, with Salix babylonica growing in wet habitats and Salix matsudana growing in relatively dry habitats. The objective of this study was to compare hydraulic and gas-exchange traits between these two closely related Salix species with contrasting natural habitats. S. matsudana had lower photosynthesis (A_max), lower stomatal conductance (g_s) and lower stem and leaf hydraulic conductance, but it exhibited higher water use efficiency (WUE_i), higher hydraulic safety and wider leaf-to-stem vulnerability segmentation as well as narrower, shorter and denser conduits and a lower ratio of leaf area to sapwood area than S. babylonica. These findings suggest that variations in hydraulic vulnerability and gas-exchange traits enable closely related Salix species to adapt to different habitats.

The relative limitation of microbes by soil organic carbon (SOC), nitrogen (N) and phosphorus (P) is linked with soil microbial activities, so how change of plant species diversity (PSD) affects microbial resource limitation would partly determine its impacts on SOC dynamics and nutrient cycling. However, the responses of microbial resource limitation to increasing PSD have poorly explored. Here, 45 plots covering a natural PSD gradient were used to investigate the effects of PSD on microbial resource limitation in a subtropical forest. Extracellular enzymatic stoichiometry along with a laboratory N and P addition experiment were used to determine microbial resource limitation. Contents of microbial biomass C, N and P significantly increased, but C:P and N:P ratios in microbial biomass were unchanged as PSD increased. Soil microbes were generally co-limited by C and P, but not by N across the 45 plots. Increasing PSD did not alter microbial N limitation, alleviated microbial C limitation and aggravated microbial P limitation. The alleviated microbial C limitation or aggravated microbial P limitation was attributed to increased soil C availability but decreased P availability, which resulted in stimulated soil C:P and N:P ratios and in turn greater C:P and N:P imbalance between soil and microbial biomass under higher PSD. Our results highlight the divergent effects of increasing PSD on microbial resource limitation. Considering that microbial C and P limitations are widespread, the patterns observed in the current study should be applicable broadly.

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

The variation and plasticity of leaf morphology play a pivotal role in the response to environmental changes for plant individuals. Discovering the large-scale pattern of such variation can reveal plants’ general adaptive strategies. We analysed leaf morphology of three widespread woody species in the northern hemisphere using specimen data from the iDigBio and GBIF databases, to investigate the variations in the individual mean traits, in the inter- and intra-individual variability of traits, and in the allometry between traits, along climatic gradients. We found that larger and wider leaves were associated with warmer, wetter and low-sunlight habitats, while smaller but wider leaves are linked to higher wind speed, indicating the response of leaf morphology to multiple climate stresses. The inter-individual variation in leaf area was smaller in colder and windier conditions, suggesting the trait convergence among individuals under environmental filtering, while the intra-individual variation in leaf relative width (RW) was smaller in warmer habitats, indicating the similar growth optimum of leaves within one individual in more favourable conditions. Finally, the allometric exponent between leaf length (X-axis) and width (Y-axis) became greater under lower solar radiation and higher wind speed, while the squared correlation coefficient (r²) indicating phenotypic integration showed a decoupling trend under colder conditions, indicating that climate affected the variation tendency of leaf RW during leaf enlargement. These results reveal the common patterns of leaf morphology responding to climate variation spatially and underscore the necessity to consider inter- and intra-individual variability when examining plant responses to environmental changes.

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.

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

Scaling relationships among twig size, leaf size and leafing intensity is pivotal in understanding plant resource allocation and carbon investment strategies. However, it remained unclear how these relationships might maintain stability across genetic traits (shade tolerance) and canopy gradients (microclimates). We investigated eight different shade-tolerant tree species within five mixed broad-leaved-Korean pine (Pinus koraiensis) forests in Northeast China. Employing linear mixed-effects models and phylogenetically independent contrasts, we examined the scaling relationships between twig-leaf size and leafing intensity. Shade tolerance altered the scaling relationships between twig and leaf size, as well as leafing intensity. We discovered that the scaling relationships between twig cross-sectional area and individual leaf area, leafing intensity and between individual leaf mass and leafing intensity were allometric (slope ≠ −1 or 1). However, the relationship between individual leaf area and individual leaf mass was isometric (slope = 1). Moreover, these scaling relationships exhibited consistent trends across canopy gradients, with shade tolerance playing a critical role in the coordinated evolution of twigs and leaves across these gradients. These results emphasized the significant role of shade tolerance in coordinating the covariation patterns between plant leaves and twigs, adopting conservative strategies in heterogeneous microclimates.

Dioecious plants show sexual dimorphism in their phosphorus (P) availability responses. However, the understanding of sex-specific strategies for P utilization and acquisition under varying soil moisture levels remains unclear. Here, we assessed a range of root functional traits, soil P properties, total foliar P concentration ([P]) and leaf chemical P fractions—inorganic P ([Pi]), metabolite P ([PM]), lipid P ([PL]), nucleic acid P ([PN]) and residual P ([PR])—as well as other leaf functional traits in female and male trees under different soil moisture levels (25% for high and 7% for low). Our results showed that females had larger specific root length under well-watered conditions, resulting in greater root foraging capacity. This led to a 36.3% decrease in soil active [Pi] in the rhizosphere and a 66.9 % increase in total foliar [P], along with all five foliar chemical P fractions ([Pi], [PM], [PL], [PN] and [PR]) compared with males. However, males exhibited significantly higher photosynthetic P utilization efficiency than females. Especially under low soil moisture levels, males exhibited a significant reduction in soil active organic P, coupled with a large increase in the exudation of soil phosphatases and carboxylates. Furthermore, the proportion of [PM] in total foliar [P] was 42.0% higher in males than in females. Mantel and Spearman correlation analyses revealed distinct coordination and trade-offs between foliar P fraction allocation and below-ground P acquisition strategies between the two sexes. Leveraging these sex-specific strategies could enhance the resilience of dioecious populations in forest plantations facing climate-induced variability.

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

Alien invasive species usually have strong regeneration and colonization abilities. However, whether invasive species have advantages in terms of regeneration and colonization abilities over native species requires further exploration. In this study, the effects of fragment types (with and without apical tips) and lengths (5, 10 and 15 cm) on the regeneration and colonization abilities of the invasive Myriophyllum aquaticum and native M. spicatum in China were studied. Fragments of M. aquaticum and M. spicatum without apical tips had an advantage in branch formation, and their regeneration ability was stronger than that of fragments with apical tips. With longer initial fragments, the root length of M. aquaticum was longer and its colonization ability was stronger. This resulted in an increase in plant length, stem node number and biomass, with an increase in fragment length. However, the colonization ability of M. spicatum was not stronger with longer fragments. On the whole, native M. spicatum had stronger regeneration and colonization abilities than the invasive species M. aquaticum. However, M. aquaticum had a higher survival rate and plant length, enabling it to quickly occupy living spaces. Our results suggest that management needs to be strengthened for both M. aquaticum and M. spicatum to avoid biological invasion.

Forest thinning and ground cover plant management play crucial roles in habitat enhancement, yet their effects on soil microbiota remain poorly understood. This study examines their impact on soil properties and bacterial communities in artifcial spruce forests (Picea asperata) within China’s Huangtuliang ecological corridor, a crucial habitat for giant pandas. Thinning signifcantly alters soil pH and total phosphorus (TP) levels, with minimal changes observed in total nitrogen (TN), microbial biomass carbon (MBC) and nitrogen (MBN). The combined effect of thinning and ground cover presence increases soil organic carbon (SOC) to 65.47 g/kg, contrasting with its absence. Thinning enhances the abundance of Proteobacteria, Acidobacteria and Chlorofexi while reducing Actinobacteria. Conversely, ground cover removal decreases Proteobacteria and Bacteroidetes but increases Chlorofexi, Verrucomicrobia and Rokubacteria. These changes lead to reduced bacterial community diversity, as indicated by a lower Shannon diversity index and distinct community composition differences demonstrated through beta-diversity analysis. Soil pH, TP and MBN are crucial in maintaining bacterial community structure, with pH and TP exhibiting the strongest correlations. Network analysis confrms the signifcant infuence of TP and pH on bacterial genera across various phyla. This study reveals the role of stochastic processes in highelevation, low-temperature ecological corridors (R² = 0.817), with thinning’s impact varying depending on the ground cover presence, thus enhancing effects post-removal by reducing dispersal limitation (migration rate, m = 0.96). These fndings highlight the ecological implications of habitat management in sensitive ecosystems and advance our understanding of microbial dynamics in critical habitats.

Leaf functional traits reflect the ecological strategies of plants and influence their growth and distribution. While variation in leaf traits has been extensively documented across species in terrestrial ecosystems, studies in wetland ecosystems can enhance the understanding of leaf trait variation along environmental gradients. Intraspecific studies are particularly valuable for exploring trait variation and its underlying mechanism. Coastal wetlands have become hotspots for studying trait variation, and the invasive Spartina alterniflora, distributed along China’s coastline, is an ideal species for investigating leaf traits variation. We examined the geographical variation and abiotic drivers of six leaf functional traits and explored the roles of phenotypic plasticity and genetic differentiation through a two-year common garden experiment. We also analyzed the relationships between leaf traits and growth performance in both field and common garden. All leaf traits exhibited significant geographical variation, which were affected by both climatic and sedimentary variables. Common garden experiment exhibited trait-dependent response, with different leaf traits showing varying degrees of plastic response or genetic differentiation. Variation in leaf size, leaf thickness and specific leaf area was primarily driven by genetic differentiation, while variation in leaf density and leaf dry matter content was largely due to phenotypic plasticity. Leaf size and thickness were positively correlated with growth performance in both field and common garden. This study advances the understanding of leaf trait variation in terrestrial ecosystems and highlights how multiple abiotic variables shape latitudinal patterns in leaf traits. The resource acquisition strategy at high latitudes in the northern hemisphere contributes to the strong growth performance of S. alterniflora, potentially facilitating its northward expansion. In contrast, the resource conservation strategy at low latitudes may hinder its southward expansion.

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.

The study aimed to thoroughly investigate the effects of nitrogen deposition on the growth, chlorophyll fluorescence and yield of Zanthoxylum bungeanum Maxim. in both monoculture and intercropping systems with Capsicum annuum L. and Glycine max. The research provided a detailed evaluation of how nitrogen deposition influenced soil and plant parameters within these intercropping systems. Key findings include: (i) In the Z. bungeanum monoculture, nitrogen deposition led to a 346.5% increase in soil NO₃⁻ levels, significantly affecting chlorophyll fluorescence parameters and decreasing soil pH. (ii) In the Z. bungeanum–C. annuum intercropping system, nitrogen deposition influenced the growth and chlorophyll fluorescence of both crops and resulted in a 261.5% increase in the root length of C. annuum. (iii) In the Z. bungeanum–G. max system, nitrogen deposition negatively impacted the chlorophyll fluorescence of G. max, reduced Z. bungeanum yields by 89.3% and altered its chlorophyll fluorescence parameters. These changes likely hindered the nitrogen-fixing capacity of G. max due to altered soil conditions. Overall, the Z. bungeanum–C. annuum system showed superior performance by enhancing soil NO₃⁻-N content. In contrast, the Z. bungeanum–G. max system experienced reduced yields due to the adverse effects of nitrogen deposition on symbiotic nitrogen fixation. These findings are crucial for developing agricultural strategies aimed at improving crop adaptability and yield in response to environmental changes.

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.

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

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

Increasing nitrogen (N) input has been recognized as one of the important factors influencing methane (CH₄) uptake and nitrous oxide (N₂O) emission in arid and semiarid grasslands. Numerous studies have examined the spatiotemporal variations of CH₄ and N₂O fluxes in various ecosystems; however, the variation of the interplay between CH₄ uptake and N₂O emission with increasing N has not yet been well understood. This study explored the relationship between CH₄ uptake and N₂O emission in a semiarid grassland in Inner Mongolia, northern China, under a gradient of 12-year N additions. We found a synergistic relationship at low-N levels, where CH₄ uptake and N₂O emission are positively correlated. Conversely, an antagonistic interaction emerged with a negative correlation between CH₄ uptake and N₂O emission observed at high-N levels, which was evidenced by a 33.62% decrease in CH₄ uptake and a 264.91% increase in N₂O emission. Further independent analysis, covering at least five N addition levels across grassland ecosystems in China, confirmed the general pattern: three of four cases showed a synergistic relationship at low-N levels and an antagonistic relationship at high-N levels. Given the increasing N deposition in the future, the dynamics between CH₄ uptake and N₂O emission are critical for understanding the impact of external N input on net greenhouse gas emission and consequent global climate change.

As a key functional trait affecting many physiological processes, leaf pH is closely related to other leaf traits at the local scale. Nevertheless, whether and how leaf pH is linked with other leaf functional traits across geographic scales remains unclear. A field survey in northern China was conducted to investigate the relationships between leaf pH and some key leaf structural (specific leaf area, SLA; leaf dry matter content, LDMC) and chemical traits (elemental concentrations; total dissolved solids, TDS; practical salinity), as well as the effects of environmental factors on these relationships. Our results showed that the trait coordination may vary in degree or direction across eco-geographic regions (arid vs. non-arid regions) and life-forms (woody vs. herbaceous plants). Generally, leaf pH was negatively related to SLA, but positively related to TDS and salinity. However, leaf pH and LDMC were negatively correlated in arid regions but positively correlated in non-arid regions; leaf pH covaried with N (similarly, with Ca, Mg and Na) in the same direction for both herbaceous and woody plants in arid regions, but not in non-arid regions. Climatic factors mainly influenced the relationships of leaf pH with leaf Ca and Fe concentrations, while soil factors mostly affected those with leaf P, Ca and Mn concentrations. Our findings highlight the divergent coordination between leaf pH and other leaf traits across life-forms and eco-geographic regions and may shed light on the in-depth understanding of the role of acid-base balance in plant eco-physiological processes and ecological adaptation over biogeographic scales.

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.

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.

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