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 (FD) 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 (SG) and cattle grazing (CG)) on the relationships between plant FD and soil carbon sequestration in meadow and desert steppe. Our findings showed that different livestock species changed the relationships between plant FD and soil organic carbon (SOC) in the meadow steppe. SG decoupled the originally positive relationship between FD and SOC, whereas CG changed the relationship from positive to negative. In the desert steppe, both SG and CG strengthened the positive relationship between FD 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 FD 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.

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, the 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 AGB and BGB of wetland plants to organic carbon.

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 protection and management of the wetland should consider the changes in hydrological connectivity (HC) 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 the 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 and constant head permeability test, the results showed a highly spatial heterogeneity of the soil structure in the YRD, hydraulic parameter (K_s) was negatively correlated with bulk density and positively with soil macropore volume, soil aeration and maximum water capacity. Using Hydrus 1-D software and the Green–Ampt model, we estimated the characteristics of the hydrodynamic process in the soil without macropores, then evaluated the effect of the soil macropore on soil hydrodynamic process 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 HC of the region. The results will further help to reveal the eco-hydrological process at a vertical scale in soil and provide a theoretical guide for wetland conservation and restoration.

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.

Algal blooms significantly affect microbial communities in wetland ecosystems. However, little is known about the succession of sediment microbial communities 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: (i) The algal blooms were dominated by Microcystis species within Cyanobacteria. Both phytoplankton abundance and biomass reached the peak in the BS, with 45.78 × 10⁵ cells/L and 5.97 mg/L, respectively. (ii) The alpha diversity indices of the sediment bacterial community showed a monotonically increasing trend, with the lowest value in the BS. Cyanobacterial blooms reduced the relative abundance of Actinobacteria and Chloroflexi, and raised that of Firmicutes, Proteobacteria and Bacteroidetes. (iii) Cyanobacterial blooms remarkably decreased the complexity of the co-occurrence network of the sediment bacterial community, which resisted extreme environmental conditions in the BS and DS by increasing positive relationships. (iv) Mantel test showed that phytoplankton biomass, T, dissolved oxygen and organic carbon had significant effects on the sediment bacterial community. The results of this study are important for the ecological management of algal blooms through microorganisms.

Functional traits play a vital role in mediating the responses of ecosystem services to environmental changes and in predicting the functioning of the 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 ecosystems. 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 and leaf dry matter content 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.

Quantifying forest stand parameters is crucial in forestry research and environmental monitoring because it provides important factors for analyzing forest structure and comprehending forest resources. And the estimation of crown density and volume has always been a prominent topic in forestry remote sensing. Based on GF-2 remote sensing data, sample plot survey data and forest resource survey data, this study used the Chinese fir (Cunninghamia lanceolata (Lamb.) Hook.) and Pinus massoniana Lamb. as research objects to tackle the key challenges in the use of remote sensing technology. The Boruta feature selection technique, together with multiple stepwise and Cubist regression models, was used to estimate crown density and volume in portions of the research area’s stands, introducing novel technological methods for estimating stand parameters. The results show that: (i) the Boruta algorithm is effective at selecting the feature set with the strongest correlation with the dependent variable, which solves the problem of data and the loss of original feature data after dimensionality reduction; (ii) using the Cubist method to build the model yields better results than using multiple stepwise regression. The Cubist regression model’s coefficient of determination (R²) is all more than 0.67 in the Chinese fir plots and 0.63 in the P. massoniana plots. As a result, combining the two methods can increase the estimation accuracy of stand parameters, providing a theoretical foundation and technical support for future studies.

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 from the 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 (SL) are more likely to be an invasive species after introduction to foreign ecosystems. In summary, exotic species with longer SL 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 models 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.

The evolution of land use/land cover (LULC) patterns significantly influences the dynamics of carbon storage (CS) in terrestrial ecosystems. In response to future environmental changes, however, most studies fail to synthesize the effects of policy pathways and evolving core driving factors on LULC projections. This article presents a systematic framework to assess the dynamic response of the terrestrial ecosystem CS to future LULC changes. After investigating spatiotemporal characteristics and driving forces, policy effects and future core driving factors are integrated into the improved Markov–future land use simulation model to project LULC across diverse scenarios. Then the Integrated Valuation of Ecosystem Service and Tradeoff model is coupled to explore CS dynamics with LULC changes. This framework was applied to the Weihe River Basin. The finding reveals that the overall proportion of cultivated land, forestland and grassland is above 85% and is significantly influenced by policy effects. Precipitation, temperature, population density and gross domestic product are core driving factors of LULC changes. Equal-interval projection is a viable approach to mitigate policy impacts by avoiding error propagation while coupling future core driving factors to improve LULC projection accuracy. Ecological protection should be emphasized in the future. The rate of increase in CS is 1.25 and 1.63 times higher than the historical trend and economic development scenario, respectively, which alleviates carbon loss from the expansion of built-up land. This research provides a valuable reference for future insight and optimization of ecological conservation strategies.

Exploring the impact of climate factors on vegetation phenology is crucial to understanding climate–vegetation interactions as well as carbon and water cycles in ecosystems in the context of climate change. In this article, we extracted the vegetation phenology data from 2002 to 2021 based on the dynamic threshold method in the source region of the Yangtze and Yellow Rivers. Trend and correlation analyses were used to investigate the relationship between vegetation phenology and temperature, precipitation and their spatial evolution characteristics. The results showed that: (i) From 2002 to 2021, the multi-year average start of growing season (SOS), end of growing season (EOS) and length of growing season (LOS) for plants were concentrated in May, October and 4–6 months, with a trend of 4.9 days (earlier), 1.5 days (later), 6.3 days/10 a (longer), respectively. (ii) For every 100 m increase in elevation, SOS, EOS and LOS were correspondingly delayed by 1.8 days, advanced by 0.8 days and shortened by 2.6 days, respectively. (iii) The impacts of temperature and precipitation on vegetation phenology varied at different stages of vegetation growth. Influencing factors of spring phenology experienced a shift from temperature to precipitation, while autumn phenology experienced precipitation followed by temperature. (iv) The climate factors in the previous period significantly affected the vegetation phenology in the study area and the spatial variability was obvious. Specifically, the temperature in April significantly affected the spring phenology and precipitation in August widely affected the autumn phenology.

Phytoplankton play an irreplaceable role as producers in maintaining lake ecosystems. Nevertheless, scant attention has been given to investigating the dispersion of phytoplankton communities and the factors influencing them across expansive areas. In this study, we present the results of a survey on the distribution of phytoplankton community and the effects of different driving factors in 11 lakes along Inner Mongolia in July–August 2020. Non-metric multidimensional scaling analysis and variance decomposition (VPA) were used to elucidate the distribution of phytoplankton communities and the response of drivers. A total of 169 species of phytoplankton from 8 phyla were detected. Both the abundance and diversity of phytoplankton in the Inner Mongolia lakes showed a trend of high in the east and low in the west (with Daihai Lake as the boundary). The Margalef index of phytoplankton significantly negatively correlated with salinity (r = −0.707, P < 0.05) and total dissolved solids (r = −0.720, P < 0.05), and both density and biomass highly significantly positively correlated with the suspended solids, Chlorophyll a and trophic level index. The VPA explained 38.9% of the changes in the phytoplankton community with the highest rate of explanation of land use. Therefore, preventing anthropogenic impacts, as well as reducing nutrient loads, can effectively ensure the ecological diversity of lake phytoplankton in lake populations with large geographical spans and varying levels of nutrients.

The ecosystems within agro-pastoral transition zones exhibit inherent fragility and heightened susceptibility to climate variability, exacerbated by profound degradation resulting from anthropogenic activities. Subsequent vegetation degradation in these areas precipitates severe soil erosion, presenting formidable challenges for ecological restoration efforts. The utilization of microtopographic structures to mitigate soil erosion and facilitate vegetation recovery stands as a prominent strategy for vegetation restoration within agro-pastoral transition zones. Despite the acknowledgment in current restoration practices that the efficacy of microtopography-based restoration is contingent upon slope, aspect and elevation, there remains a notable absence of precise observed information on this correlation. This study, conducted in the Bashang Grassland, a typical agro-pastoral transition zone in northern China, aims to fill the information gap concerning the correspondence between microtopographic structures and restoration outcomes. Our findings revealed that microtopography has a significant impact on vegetation characteristics, with outcomes varying by location. Shaded slopes displayed higher biomass and density compared with sunny slopes and valleys. While microtopography affected community structure, it did not substantially alter species richness, highlighting the critical role of location and pit construction in successful restoration endeavors. This study provides insights for the selection, design and assessment of microtopography-based restoration in vulnerable ecosystems.

A meandering riverbank plays a vital role in maintaining natural river ecosystems, providing habitats for riparian vegetation. However, dams have significantly altered riverbank shapes. To restore the riparian ecosystems, it is imperative to understand how different riverbank curvatures influence them. This study aims to uncover the ecological impacts of riverbank curvature on the structure and assembly process of plant communities in the riparian zone of the Yangtze River, regulated by the Three Gorges Dam (TGD) in China. We categorized the riparian zones into four types: cove, lobe, wavy and linear shapes. We documented the composition and diversity of riparian plant communities. Our findings revealed that wavy and cove riverbanks exhibited greater species diversity (with Shannon–Wiener diversity index values 1.5× higher) compared to communities along linear riverbanks. Furthermore, the analysis of functional traits indicated that wavy riverbanks promoted the differentiation of plant functional traits, thus enhancing ecosystem functions, with functional dispersion index (FDis) values 1.3 times higher than those of linear riverbanks. Significant variations in the assembly of riparian communities were also observed among different riverbanks, with standardized effect size (SES) values indicating a higher degree of niche differentiation in cove riverbanks (SES = 0.4) compared to linear riverbanks (SES = –0.6). These results highlight the ecological importance of diverse riverbank curvatures in influencing the diversity, structure and assembly of riparian communities along the waterway. In summary, this study underscores the necessity of maintaining or restoring various natural morphological curvatures when rehabilitating riparian communities along rivers impacted by human activities.

In the Eurasian forest-steppe, with increasing aridity, the balance between naturally co-existing forest and grassland patches is expected to shift towards grassland dominance in the long run, although feedback mechanisms and changes in land-use may alter this process. In this study, we compared old and recent aerial photographs of Hungarian forest-steppes to find out whether and how the forest proportion and the number of forest patches change at the decadal time scale. The percentage area covered by forest significantly increased in all study sites. The observed forest encroachment may be a legacy from earlier land-use: due to ceased or reduced grazing pressure, forests are invading grasslands until the potential forest cover allowed by climate and soil is reached. The number of forest patches significantly increased at one site (Fülöpháza), while it decreased at two sites (Bugac and Orgovány) and showed no significant change at the fourth site (Tázlár). This indicates that forest encroachment can happen at least in two different ways: through the emergence of new forest patches in the grassland, and through the extension and coalescence of already existing forest patches. Though the present work revealed increasing tree cover at a decadal time scale, the dynamic process should be monitored in the future to see how the vegetation reacts to further aridification. This could help devise a conservation strategy, as the woody/non-woody balance has a profound influence on basic ecosystem properties.

Flooding events tend to destroy the original flood-intolerant vegetation in riparian zones, but the flood-tolerant species can confront the stress, and contribute to the riparian ecosystem. Grass species, Hemarthria altissima, are usually dominant in the riparian zones. This species is considered as good forage which is usually grazed by livestock or mowed by local people. Therefore, the apical tissues of the plants are often removed, and the plants have to grow without stem apexes, during their life cycle. In this study, we aimed to examine the differences in growth performance of intact versus apex-cut individuals of H. altissima upon complete submergence. Two groups of H. altissima plants (with and without shoot apexes) were treated with dark non-submergence and dark complete submergence conditions for 200 days. During the experiment, we measured plant growth, biomass changes in plant organs, and the consumption of non-structural carbohydrates (NSC) by different tissues. During submergence, shoot elongation stopped, and around six lateral buds were developed averagely by each plant without apexes. This growth performance finally caused 60% decline of NSC in underground parts. The relatively intensive consumption of carbohydrates in submerged apex-removed plants induced the 21% stem length decreased under water, which indicated the decreasing submergence tolerance of plants with shoot apex removed. Therefore, we suggest that when using H. altissima for restoring degraded riparian ecosystems, the shoot apexes should be protected from grazing by livestock or harvesting by local people in order to maintain the submergence tolerance of H. altissima.