Alpine treelines are considered ecological monitors recording the impacts of climate change on trees and forests. To date, most treeline research has focused on how climate change drives treeline dynamics. However, little is known about how biotic interactions mediate treeline shifts, particularly in the case of tree recruitment, a bottleneck of treeline dynamics. We hypothesized that interspecific and intraspecific facilitation determined the establishment and survival of tree seedlings at alpine treelines. To test this hypothesis, 630 Abies georgei var. smithii seedlings with different ages (4-6, 7-9, and 10-15 years old) were transplanted into three growth habitats (canopy-in, canopy-out, and meadow) across the alpine treeline ecotone (4300-4500 m) in the Sygera Mountains, on the southeastern Qinghai-Tibetan Plateau. Microclimate, height growth, mortality rates, and leaf functional traits of transplanted seedlings were measured over three years. We found that the variations in leaf functional traits were driven by microclimate. After the transplantation, the leaf concentrations of soluble sugars and starch and C:P ratio increased, whereas leaf size decreased. The resource use of seedlings gradually shifted to a more conservative strategy as indicated by changes in non-structural carbohydrates and nutrient concentrations. Radiation, temperature, and moisture conditions, mediated by plants interactions, influenced seedling mortality and annual growth by affecting leaf morphological traits. Our findings illustrate how facilitation plays a crucial role in altering solar radiation and leaf trait functioning, determining seedling survival and growth at alpine treelines. We provide new insights into the underlying mechanisms for tree establishment and alpine treeline shifts in response to climate change.

Global climate change is expected to have a significant impact on ecosystems worldwide, especially for alpine meadow ecosystems which are considered as one of the most vulnerable components. However, the effects of global warming on the plant Nitrogen-Phosphorus stoichiometry and resorption in alpine meadow ecosystems remain unclear. Therefore, to investigate the plant Nitrogen-Phosphorus stoichiometry and resorption in alpine meadow ecosystems on the Qinghai- Tibet Plateau, we conducted an artificial warming study using open-top chambers (OTCs) over the 3- years of warming period. We selected three dominant species, four height types of OTCs (0.4 m, 0.6 m, 0.8 m and 1 m) and four warming methods (year-round warming, winter warming, summer-autumn-winter warming and spring-summer-autumn warming in the experiment) in this experiment. In our study, soil temperature significantly increased with increasing the height of OCTs under the different warming methods. Kobresia pygmaea presented an increase in nitrogen (N) limitation and Kobresia humilis presented an increase in phosphorus (P) limitation with increasing temperature, while Potentilla saundersiana was insensitive to temperature changes in terms of nitrogen and phosphorus limitations. Both nitrogen resorption efficiency (NRE):phosphorus resorption efficiency (PRE) and N:P trends in response to rising temperatures were the same direction. The differential responses of chemical stoichiometry of the three species to warming were observed, reflecting that the responses of nitrogen and phosphorus limitations to warming are multifaceted, and the grassland ecosystems may exhibit a certain degree of self-regulatory capability. Our results show that using chemical dosage indicators of a single dominant species to represent the nitrogen and phosphorus limitations of the entire ecosystem is inaccurate, and using N:P to reflect the nutritional limitations might have been somewhat misjudged in the context of global warming.

As a main method of forest regeneration, stump sprouting plays a crucial role in forest community succession and vegetation restoration. We aimed to investigate the response of stump sprouting capacity to stubble height, unveil its nutrient-accumulation and allocation strategies, and determine the appropriate stubble height most favorable for stump sprouting of Hippophae rhamnoides ssp. sinensis. Fifteen-year plants with signs of premature aging were coppiced at 0, 10, and 20 cm from the ground level. With the increase in stubble height, the number of stump sprouts increased linearly, and the survival rate decreased linearly. The height, diameter, and cluster width of stump sprouts first increased, reached the highest level at a stubble height of 10 cm, and then decreased. The contents and reserves of N, P, K, Ca, and Mg showed a similar trend as the growth, positively correlating with each other. Compared to the control (no coppicing), the coppicing increased the nutrient element allocation of leaves, vertical roots, and horizontal roots. Magnesium played an important role in stump sprouting. The findings suggest that coppicing changed the accumulation ability and allocation pattern of nutrient elements, and further affected the sprouting ability of stumps. The best stubble height for stump sprouting and nutrient accumulation potential was 11.0-14.0 cm estimated by the regression.

Elevated CO₂ and warmer temperatures represent the future environmental conditions in the context of global change. A good understanding of plant response to their combined effects is, therefore, critically important for predicting future plant performance. This study investigated the photosynthetic acclimation of amur linden (Tilia amurensis Rupr.) seedlings (current year, about 60 cm tall), a shade-tolerant tree species in the temperate broadleaf deciduous forest, to the combination of current CO₂ concentration and temperature (CC) and the combination of the predicted future CO₂ concentration and temperature (FC). The results show that FC promoted aboveground growth, but reduced photosynthetic capacity (V_cmax: maximum rate of RuBP carboxylation and J_max: maximum photosynthetic electron transport rate). However, the photosynthetic rate measured under the corresponding growth CO₂ concentration was still higher under FC than under CC. FC depressed the photosynthetic limiting transition point (C_i-t, An-t) from Rubisco carboxylation to RuBP regeneration, i.e., An-t decreased without a change in C_i-t. FC did not change leaf N concentration but increased the total leaf N content per tree and photosynthetic nitrogen utilization efficiency. This suggests that N utilization, rather than photosynthetic capacity, may play an important role in the acclimation of the species to future climatic conditions. This study provides new insights into the photosynthetic acclimation of amur linden and can be used to predict its possible performance under future climatic conditions.

A belowground bud bank is a collection of asexual propagules produced by the underground storage organs of geophytes. Renewal through belowground bud banks is the main reproductive strategy of geophytes. The belowground bud bank density reflects the potential renewal capacity of geophyte communities. However, the effects of different perturbation regimes and habitats on belowground bud bank density of geophytes are not comprehensively understood. Moreover, whether different types of belowground bud banks respond differently to perturbations is still unclear. For this meta-analysis, relevant papers on effects of environmental perturbations on belowground bud bank density of geophytes were systematically collected. The cumulative effect size of different perturbation regimes and habitats on belowground bud banks among different bud types was analyzed. Overall, the effect of environmental perturbations on belowground bud bank density was small, which may result from opposite or fluctuating responses of bud banks to different perturbations. Drought negatively affected bud bank density. Environmental perturbations decreased rhizome bud density but increased tiller bud density. In wetlands, perturbations decreased belowground bud bank density. However, no significant effect was found for other habitat types. In general, belowground bud banks of geophytes are highly resistant and resilient. Changes in belowground bud bank density depend on the type of perturbations, the habitats in which plants are distributed, and the type of bud banks.

Mongolian herder households maintain the health and condition of their livestock by adapting to the characteristics of the local vegetation distribution. Thus, predicting future vegetation changes is important for stable livestock grazing and sustainable rangeland use. We predicted the distributional extent of rangeland vegetation, specifically desert steppe, steppe, and meadow steppe communities, for the period 2081-2100, based on vegetation data obtained from a previous study. Rangeland vegetation data collected in Mongolia (43-50°N, 87-119°E) between 2012 and 2016 (278 plots), were classified into community types. Species distribution modeling was conducted using a maximum entropy (MaxEnt) model. Distribution data for desert steppe, steppe, and meadow steppe communities were used as objective variables, and bioclimatic data were obtained from WorldClim for use as explanatory variables. CMIP6-downscaled future climate projections provided by WorldClim were used for future prediction. The area under the curve values for the desert steppe, steppe, and meadow steppe models were 0.850, 0.847, and 0.873, respectively. Suitable habitat was projected to shrink under all scenarios and for all communities with climate change. The extent of reduction in potential suitable areas was greatest for meadow steppe communities. Our results indicate that meadow steppe communities will transition to steppe communities with future climate change.

Estimating the effects of extreme drought on the photosynthetic rates (Pn) of dominant plant species is crucial for understanding the mechanisms driving the impacts of extreme drought on ecosystem functioning. Extreme drought may result from either reduced rainfall amounts or decreased rainfall frequency, and the impacts of different patterns of extreme drought may vary greatly. In addition, different grasslands likely appeared varied sensitivity to different extreme drought patterns. However, there have been no reports on the effects of different extreme drought patterns on dominant species Pn in different grassland types. Here, we conducted multi-year extreme drought simulation experiments (reducing each rainfall event by 66% during growing season, CHR vs. completely excluding rainfall during a shorter portion of growing season, INT) in two different grasslands (desert grassland vs. typical grassland) from 2014. The Pn of two dominant species in each grassland were measured in July and August 2017. Both CHR and INT significantly decreased dominant species Pn, with INT causing more negative impacts on Pn regardless of grassland types. The response ratios of Pn in desert grassland were generally higher than that of typical grassland, especially for Leymus chinensis in CHR. These results indicate that decreased rainfall frequency had a more negative effect on Pn compared to reduced rainfall amount, with grassland types changing the magnitude, but not the direction, of the effects of extreme drought patterns. These findings highlight the importance of considering extreme drought patterns and grassland types in ecosystem management in the face of future extreme droughts.

Although biotic and abiotic factors have been confirmed to be critical factors that affect the community dynamics, their interactive effects have yet to be fully considered in grassland degradation. Herein, we tested how soil nutrients and microbes regulated plant-soil feedback (PSF) in a degraded alpine grassland. Our results indicated that, from non-degraded (ND) to severely degraded (SD), significantly (P<0.05) decreased soil total carbon (from 17.66 to 12.55 g/kg) and total nitrogen (from 3.16 to 2.74 g/kg) were detected. Despite higher nutrients in ND soil generating significantly (P<0.05) positive PSF (0.52) on monocots growth when the soil was sterilized, a high proportion of pathogens (36%) in ND nonsterilized soil resulted in a strong negative PSF on monocots. By contrast, the higher phenotypic plasticity of dicots coupled with a higher abundance of mutualists and saprophytes (70%) strongly promoted their survival and growth in SD with infertile soil. Our findings identified a novel mechanism that there was a functional group shift from monocots with higher vulnerability to soil pathogens in the ND fertile soil to dicots with higher dependence on nutritional mutualists in the degraded infertile soil. And the emerging irreversible eco-evolutionary in PSF after degradation might cause a predicament for the restoration of degraded grassland.

Globalization of social and economic activities has led to the large-scale redistribution of plant species. It is still unclear how the traits aid the successful invasion of alien species. Here, we downloaded global plant trait data on TRY-Plant Trait Database and classified alien species in China into four groups: high, medium, need attention, and harmless according to their distribution and degree of harm to local plant communities based on existed studies. The relationship between plant functional traits and invasion level was clarified, and we established a prediction model based on plant functional traits and taxonomy. The results showed that species with smaller seeds, smaller individuals, lower special leaf area and longer seed bank longevity are more likely to be an invasive species after introduction to foreign ecosystems. In summary, exotic species with longer seedbank longevity and lower seed dry mass are more likely to be invasive in China. We also trained two predictive models to check if we can predict a species’ invasion. Combining the two model together, statistically, we could predict if a species is invasive from its traits and taxonomy with a 91.84% accuracy. This model could help local governments, managers and stakeholders to evaluate shall we introduce some plant species in China.

Algal blooms significantly affect microbial community in wetland ecosystems. However, little is known about the succession of sediment microbial community during algal blooms. This study aimed to investigate the temporal patterns of sediment bacterial community structure and function succession during algal blooms (March to May, 2022) with high-throughput sequencing technology. To this end, algal blooms were divided into the bloom stage (BS), decomposition stage (DS) and end stage (ES). The results showed that: (1) The algal blooms were dominated by Microcystis species within Cyanobacteria. Both phytoplankton abundance and biomass reached the peak in the BS, with 45.78×10⁵T, DO, and OC had significant effects on the sediment bacterial community. The results of this study are important for the ecological management of algal blooms through microorganisms.

Asymmetric seasonal warming, characterized by more pronounced temperature increases in winter than in summer, has become a critical feature of global warming, especially in cold and high-altitude regions. Previous studies have primarily focused on year-round warming, while comparatively less attention was paid to winter warming. However, a significant knowledge gap exists regarding the impacts of winter warming on ecosystem functions. To address this, we conducted an 8-year manipulated warming experiment in an alpine grassland on the Tibetan Plateau, employing three treatments: no warming, year-round warming, and winter warming. We found that neither year-round warming nor winter warming significantly alter species richness at the community-level. Notably, community biomass stability was maintained via species asynchrony. However, warming exerted significant effects on the plant abundance groups (dominant, common and rare species). Specifically, winter warming enhanced the stability of dominant species by increasing species asynchrony of dominant species, as the compensatory dynamics occurred between the grass and forbs. In contrast, year-round warming reduced the stability of common species, correlated with an increase in species richness and a decline in asynchrony among common species. Thus, our study underscores the capacity of alpine grassland to maintain community biomass stability via asynchrony dynamics of species under different warming conditions, although the stability of different abundance groups would be changed. Importantly, our results provide valuable insights for understanding the alpine grassland ecosystem on the Tibetan Plateau.

Coastal wetland ecosystems are increasingly threatened by escalating salinity levels, subjecting plants to salinity stress coupled with interactions in community. Abiotic factors can disrupt the balance between competition and facilitation among plant species. Investigating the effects of different neighboring species and trait plasticity could extend the stress gradient hypothesis and enhance understanding of vegetation distribution and diversity in salt marshes. We conducted a greenhouse experiment and investigated the plastic response of wetland grass Phragmites australis to 7 neighboring plants of 3 functional types (conspecifics, graminoids, and forbs) under soil salinity (0 g/L and10 g/L). Plant height, base diameter, density, leaf thickness, specific leaf area, total and part biomasses were measured. Additionally, the Relative Interaction Index (RII, based on biomass) and the Relative Distance Plasticity Index (RDPI) were calculated. Salinity significantly reduced the biomass, height, density, and diameter of P. australis. The functional types of neighboring plants also significantly affected these growth parameters. The influence of graminoids on P. australis was negative under 0 g/L, but this negative effect shifted to positive facilitation under 10 g/L. The facilitation effect of forbs was amplified under salinity, both supporting the stress gradient hypothesis. The growth traits of P. australis had plastic response to salinity and competition, such as increasing belowground biomass to obtain more water and resources. The RDPI was higher under salt condition than competitive conditions. The plant-plant interaction response to stress varies with plant functional types and traits plasticity.

Climatic warming has advanced the spring phenology of plants and disrupted the alignment of phenology with weather patterns. Such misalignments can cause problems as extreme weather events become more frequent and thus impact the survival, growth, and reproduction of plants. To prevent freezing within their cells during the growing season, plants adopt a supercooling strategy. However, the weather event severity and seasonal timing may impact plant’s recovery after a freezing event. We conducted experiments to investigate how extreme freezing events of four different severities impacted the supercooling points and senescence of two dominant alpine plant species, Potentilla saundersiana (mid-summer flowering) and Gentiana parvula (late-summer flowering) on the Qinghai-Tibet Plateau (QTP). We also explored how phenological stage impacted P. saundersiana's response to freezing events. We found that both species exhibited supercooling upon exposed to frost damage. However, the average supercooling point for P. saundersiana was -6.9 °C and was influenced by minimum temperature, duration and phenological stage. Whereas, the average supercooling point for G. parvula was -4.8 °C, and neither minimum temperature nor duration had effect on the supercooling point. In addition, the minimum temperature treatment of -10 °C caused death in both plants when held constant for 4 h. Our study provides the first experimental dataset exploring the supercooling points of alpine plants on the QTP. Given the increasing probability of alpine plants encounter frost events, these results are of great significance for understanding growth and survival strategies of alpine plants to cope with the adverse effects of extreme climate.

Warming and precipitation are key global change factors driving soil carbon (C) dynamics in terrestrial ecosystems. However, the effects of warming and altered precipitation on soil microbial diversity and functional genes involved in soil C cycling remains largely unknown. We explored the effects of warming and increased precipitation on soil C cycling in a temperate desert steppe of Inner Mongolia using metagenomic sequencing. We found that plant richness, Shannon-Wiener and Simpson index were negatively affected by warming. In contrast, increased precipitation significantly influenced Shannon-Wiener and Simpson index. Warming reduced soil microbial species by 5.4% while increased precipitation and warming combined with increased precipitation led to increases in soil microbial species by 23.3% and 2.7%, respectively. The relative abundance of Proteobacteria, which involve C cycling genes, was significantly increased by warming and increased precipitation. Warming significantly reduced the abundance of GAPDH (Calvin cycle) and celF (cellulose degradation) while it enhanced the abundance of glxR (lignin degradation). Increased precipitation significantly enhanced the abundance of pgk (Calvin cycle), coxL (carbon monoxide oxidation), malZ (starch degradation), and mttB (methane production). Moreover, a wide range of correlations among soil properties and C cycling functional genes was detected, suggesting the synergistic and/or antagonistic relationships under scenario of global change. These results may suggest that warming is beneficial to soil C storage while increased precipitation negatively affects soil C sequestration. These findings provide a new perspective for understanding the response of microbial communities to warming and increased precipitation in the temperate desert steppe.

Functional traits play a vital role in mediating the responses of ecosystem services to environmental changes and in predicting functioning of ecosystem. However, the connection between functional traits and ecosystem services has become increasingly intricate due to climate change and human activities for degraded ecosystems. To investigate this relationship, we selected 27 sampling sites in the Yanhe River Basin of the Chinese Loess Plateau, each containing two types of vegetation ecosystems: natural vegetation and artificial vegetation ecosystem. At each sampling site, we measured ecosystem services and calculated the composition index of community traits. We established a response-effect trait framework that included environmental factors such as climate, elevation, and human activities. Our results showed that leaf tissue density (LTD) was the overlapping response and effect trait when responding to climate change. LTD is positively correlated with mean annual temperature and negatively correlated with supporting services. Under the influence of human activities, leaf nitrogen content (LNC) and leaf dry matter content (LDMC) were carriers of environmental change. Comparing the two vegetation ecosystems, the relationship between functional traits and ecosystem services showed divergent patterns, indicating that human activities increased the uncertainty of the relationship between functional traits and ecosystem services. Trait-based ecology holds promise for enhancing predictions of ecosystem services responses to environmental changes. However, the predictive ability is influenced by the complexity of environmental changes. In conclusion, our study highlights the importance of understanding the complex connection between functional traits and ecosystem services in response to climate changes and human activities.

The protection and management of the wetland should consider the changes in hydrological connectivity caused by the structural modifications of the soil macropores. The main purpose of our work is to clarify and quantify the influence of the soil macropores volume on vertical soil hydrodynamic process mechanically and statistically by taking the form of a case-study in Yellow River Delta (YRD), and further reveal the vertical hydrological connectivity in this area. Based on X-ray computed tomography (CT) and constant head permeability test, the results showed a highly spatial heterogeneity of the soil structure in the YRD, hydraulic parameter (Ks) was negatively correlated with bulk density (BD) and positively with soil macropore volume, soil aeration (SA), and maximum water capacity (MWC). Using Hydrus 1-D software and the Green-Ampt model, we estimated the characteristics of hydrodynamic process in the soil without macropores, then evaluated the effect of the soil macropore on soil hydrological connectivity by comparing the experimental results with the simulation results. We found that increasing soil microporosity improved the convenience of water movement, which would enhance the hydrological connectivity of the region. The results will further help to reveal the eco-hydrological process at vertical scale in soil and provide a theoretical guide for wetland conservation and restoration.

Leaf trichomes are derived from epidermal cells and serve an important function in regulating leaf heat balance and gas exchange. Variation in leaf functional traits is critical for predicting how plants will react to global climate change. In this study, we aimed to investigate how leaf trichome densities vary along large geographic gradients and how they interact with with stomata in response to environmental change. We investigated the leaf trichome densities of 44 Quercus variabilis populations in Eastern Asia (24° to 51.8° N, 99° to 137° E) and their correlation with climatic factors and stomatal traits. In addition, 15 populations were grown in a common garden to study their adaptive variation and coordination with stomata. The mean value of trichome density in situ conditions was 459.78 trichome mm^-2 with a range of 325.79 to 552.38 trichome mm^-2. Trichome density increased with latitude and decreased with longitude. Both temperature and precipitation reduced the trichome density. Moreover, trichome density was positively correlated with stomatal density whether in situ or in the common garden, and both increased with drought. Our results suggested that leaf trichomes possess highly adaptive variation and are in close coordination with stomata in response to climate change. Our findings provide new insights toward elucidating the interactions between leaf traits and the adaptive strategies of plants under climate change.

Hemisphere photos are now widely applied to provide information about solar radiation dynamics, canopy structure and their contribution to biophysical processes, plant productivity and ecosystem properties. The present study aims to improve the original “edge detection” method for binary classification between sky and canopy, which works not well for closed canopies. We supposed such inaccuracy probably is due to the influence of sky pixels on their neighbor canopy pixels. Here we introduced a new term “neighbor distance”, defined as the distance between pixels participated in the calculation of contrast at the edges between classified canopy and sky, into the “edge detection” method. We showed that choosing a suitable neighbor distance for a photo with specific gap fraction can significantly improve the accuracy of the original “edge detection” method. Combining the modified “edge detection” method and an iterative selection method, with the aid of an empirical power function for the relationship between neighbor distance and manually verified gap fraction, we developed a ND-IS (Neighbor Distance-Iteration Selection) method that can automatically determine the threshold values of hemisphere photos with high accuracy and reproductivity. This procedure worked well throughout a broad range of gap fraction (0.019 to 0.945) with different canopy composition and structure, in five forest biomes along a broad gradient of latitude and longitude across Eastern China. Our results highlight the necessity of integrating neighbor distance into the original “edge detection” algorithm. The advantages and limitations of the method, and the application of the method in the field were also discussed.

Natural wetland areas in China have experienced a continuous decline over the past two decades, which is partly due to the lack of comprehensive wetland protection laws and regulations. Despite investing over 4.24 billion USD in wetland conservation and restoration since 2000, the deterioration of wetlands persists. This study reviews the development of global wetland protection laws and regulations, analyzes the progress of wetland legislation in China, and explores the impact of economic development levels on wetland protection legislation, while also providing an in-depth interpretation of the core elements of the "Wetland Protection Law of the People's Republic of China." The results indicate that since the late 1940s, wetland protection laws and regulations have begun to emerge, with most developed countries gradually implementing related policies between the 1980s and 1990s; about 71% of wetland protection laws are concentrated in 29 countries, while 69 countries still lack specific wetland protection laws. An analysis of 962 global documents reveals that wetland protection legislation mainly focuses on the protection of water resources, species, and ecosystems. China's wetland legislation started late, with the "Wetland Protection Law of the People's Republic of China" being officially implemented only in June 2022. Furthermore, the study points out that economic development plays a crucial role in wetland legislation worldwide. Lastly, the article summarizes the key features of the "Wetland Protection Law of the People's Republic of China," including the improvement of the environmental protection legislative system, increased penalties for illegal occupation of wetlands, clearer protection goals, and the assurance of the integrity and connectivity of wetland ecosystems through stringent policies.

The biomass of wetland plants is highly responsive to environmental factors and plays a crucial role in the dynamics of the soil organic carbon (SOC) pool. In this study, we collected and analyzed global data on wetland plant biomass from 1980 to 2021. By examining 1134 observations from 182 published papers on wetland ecosystems, we created a comprehensive database of wetland plant above-ground biomass (AGB) and below-ground biomass (BGB). Using this database, we analyzed the biomass characteristics of different climate zones, wetland types, and plant species globally. Based on this, we analyzed the differences between the biomass of different plant species and the linkage between AGB and BGB and organic carbon. Our study has revealed that wetland plant AGB is greater in equatorial regions but BGB is highest in polar areas, and lowest in arid and equatorial zones. For plant species, BGB of the Poales is higher than the AGB but Caryophyllales, Cyperales, and Lamiales have higher AGB. Moreover, our findings indicate that BGB plays a more significant role in contributing to the organic carbon pool compared to AGB. Notably, when BGB is less than 1 (t C ha^-1), even slight changes in biomass can have a significant impact on the organic carbon pool. And we observed that the SOC increases by 5.7 t C ha^-1 when the BGB content is low, indicating that the SOC is more sensitive to changes in biomass under such circumstances. Our study provides a basis for the global response of above- and below-ground biomass of wetland plants to organic carbon.

Grazing exerts a profound influence on both the plant diversity and productivity of grasslands, while simultaneously exerting a significant impact on regulating grassland soil carbon sequestration. Moreover, besides altering the taxonomic diversity of plant communities, grazing can also affect their diversity of functional traits. However, we still poorly understand how grazing modifies the relationship between plant functional diversity and soil carbon sequestration in grassland ecosystems. Here we conducted a grazing manipulation experiment to investigate the effects of different grazing regimes (no grazing; sheep grazing; cattle grazing) on the relationships between plant functional diversity and soil carbon sequestration in meadow and desert steppe. Our findings showed that different livestock species changed the relationships between plant functional diversity and soil organic carbon (SOC) in the meadow steppe. Sheep grazing decoupled the originally positive relationship between functional diversity and SOC, whereas cattle grazing changed the relationship from positive to negative. In desert steppe both sheep and cattle grazing strengthened the positive relationship between functional diversity and SOC. Our study illuminates the considerable impact of livestock species on the intricate mechanisms of soil carbon sequestration, primarily mediated through the modulation of various measures of functional trait diversity. In ungrazed meadows and grazed deserts, maintaining high plant functional diversity is conducive to soil carbon sequestration, whereas in grazed meadows and ungrazed deserts, this relationship may disappear or even reverse. By measuring the traits and controlling the grazing activities, we can accurately predict the carbon sequestration potential in grassland ecosystems.

Direct sewage discharge may enhance soil nitrous oxide (N₂O) emissions, worsening the greenhouse effect. However, the effects of sewage discharge into bogs on N₂O flux, drivers, and influencing mechanisms remain unclear. Additionally, investigating the impact of reclaimed water on N₂O flux is important for bog replenishment and water shortage alleviation. This study simulated sewage from different sources into a bog and analyzed N₂O fluxes, soil (organic carbon, total nitrogen, ammonium nitrogen, nitrate nitrogen, total phosphorus, available phosphorus, pH, and electrical conductivity), plant (species richness and biomass), and microorganisms (ammonia-oxidizing archaea, napA, nirS, nirK, and nosZ genes). Results showed that the reclaimed water did not significantly change N₂O flux, while 50% tap water mixed with 50% domestic sewage and domestic sewage significantly increased the N₂O flux. Among soil factors, available nitrogen and pH were key in influencing N₂O flux. Among plant parameters, species richness was the primary factor affecting N₂O flux. Nitrogen transformation functional genes contributed the most to the increase in the N₂O fluxes, with an increase in domestic sewage input leading to a higher abundance of these genes and subsequent N₂O emissions. Therefore, domestic sewage should be considered, as it significantly increases N₂O emissions by affecting the soil, plants, and microorganisms, thereby increasing the global warming potential. This study's findings suggest that using treated reclaimed water for bog replenishment could be an environmentally friendly approach to wetland management.

Rubber plantations have increased significantly under unprecedented economic growth in tropical areas, which leads to soil degradation and thereby alters soil hydrological processes. However, our understanding of how forest conversion affects soil hydrological processes remains unclear. Here, we collected soil samples from secondary forests (SF) and rubber plantations (RP) to determine the soil hydrological characteristics. We found the topsoil (0-20 cm) water retention in SF was higher than that of RP but displayed the contrast pattern in a deeper soil layer (20-60 cm). Meanwhile, the soil infiltration rates among two vegetation types decreased significantly with infiltration time, with higher stable soil infiltration rates in SF than those in RP. Moreover, soil properties were also impacted by the forest conversion, such as the topsoil capillary porosity and total porosity in SF were higher than those of RP but contrasted in a deep soil layer. In comparison, the topsoil bulk density in SF was lower than that of RP, but contrasted in the deep soil layer and reached a significant level in the 0-10 cm and 40-50 cm (P<0.05). Overall, the soil water retention was mainly determined by the capillary porosity, which could explain 31.56% of total variance in soil water retention, followed by total porosity (26.57%) and soil bulk density (26.47%), whereas soil texture exerts a week effect on soil water retention. Therefore, we can conclude that the conversion of tropical rainforest into rubber plantations may accelerate soil erosion owing to its lower soil water retention and soil infiltration rates.

Although the effects of arbuscular mycorrhizal fungi (AMF) on host plants have been well documented, whether the effects of AMF on parental generations could affect offspring performance is not fully clear. We conducted a common garden experiment to determine whether AMF status of host plants (Medicago truncatula) affect phenotype and transcriptome expression of their offspring. Seeds from four type parental treatments (low- phosphorus (P) soil without AMF, low-P soil with AMF, high-P soil without AMF and high-P soil with AMF were grown under low-P (LPS) and normal-P soil (OHS) conditions. The flowering pattern of LP offspring was similar to their parents that plants with AMF flowered earlier than those without AMF under OHS condition but was opposite under LPS condition. The transcriptome differential analysis showed that some differential transcripts (45 for parental plants growing under low-P condition and 3 for parental plants growing under high-P condition) expression patterns between offspring were similar, and only affected by parental AMF status regardless of the P environment that offspring grew. Others (146 for parental plants growing under low-P condition and 2 for parental plants growing under high-P condition), however, were affected both by the parental AMF status and the offspring P environment. Meanwhile, the number of differential transcripts between offspring whose parental plants grew under high-P condition were far less than under low-P condition. These results indicate that AMF may not only affect the current generation of host plants but also affect the offspring especially when their parents have experienced a stressful environment.