In order to analyze the influence of river-lake connection project on the carrying capacity of water and soil resources in western Jilin Province, and promote the optimal allocation of regional water and soil resources. Based on the ecological footprint model, this paper analyzed the dynamic changes of the spatial and temporal patterns of ecological footprint and ecological carrying capacity of water and soil resources in the western region of Jilin Province from 2016 to 2020. According to the results, the coupling coordination degree model was used to quantitatively analyze the coupling coordination status of ecological carrying capacity of water and soil resources. And the impact of river and lake connectivity projects on the carrying capacity of water and soil resources is discussed. The results show that the ecological footprint of per capita water resources in western Jilin Province shows a downward trend from 2016 to 2020. The overall ecological carrying capacity is on the rise, with an average value of 0.39 hm²/person. The ecological environment of water resources is seriously deteriorated and the water resources are tight. The ecological footprint of per capita land resources in western Jilin Province increased from 0.355 hm²/person in 2016 to 0.403 hm²/person in 2020, and the ecological carrying capacity increased slowly, the land resources have a larger space for use. The river-lake connectivity project has played a positive role in the ecological carrying capacity of water resources in western Jilin Province. However, in the implementation process, the coordination between water resources and land resources is insufficient, resulting in a certain degree of decline in the coupling coordination degree of ecological carrying capacity of water and soil resources. It can be seen that in the future planning, the western part of Jilin Province needs to pay more attention to the comprehensive management of water and soil resources, and gradually realize the efficient allocation of water and soil resources according to local conditions.

Spartina alterniflora is a common invasive species in coastal wetlands of China. Rapid and accurate identification of S. alterniflora has been one of the key focuses in coastal wetland ecological research. Traditional identification methods primarily rely on manual field surveys, which are labor-intensive, time-consuming, and costly. Moreover, existing remote sensing-based identification studies largely depend on a single normalized vegetation index, which often fails to adequately address the spectral confusion between S. alterniflora and co-occurring vegetation species. To address these limitations, taking the Xiangshan Port in Ningbo City, Zhejiang Province as the study area, this research utilized the Red Edge Index (REI) generated from the red-edge bands of Sentinel-2 remote sensing imagery, combining with the phenological characteristics of S. alterniflora during its peak growth season (from June to July 2022) and senescence period (from December 2022 to January 2023), constructed an identification model integrating temporal spectral and phenological information. Through the Google Earth Engine platform, obtain and preprocess image data to identify S. alterniflora in the study area, and systematically optimize the number of decision trees to improve model performance. The results showed that compared with the commonly used Normalized Difference Vegetation Index (NDVI), REI provided better identification performance for S. alterniflora. Furthermore, compared with remote sensing identification methods without phenological features, incorporating the phenological characteristics of S. alterniflora reduced the misidentification rate of surrounding plants. When the number of random forest decision trees was set to 7, the overall identification accuracy combining S. alterniflora vegetation phenological features reached 99.18%, with a Kappa coefficient of 0.981 7. The results were significantly better than the classification results using only NDVI or single-phase data. Spatial analysis further indicated that this method could effectively suppress spectral confusion caused by seasonal phase changes and reduce misjudgment between the edge area of the tidal ditch and the remaining reed plant area. This study verified the potential of the red-edge band of sentine1-2 in the identification of vegetation phenology, providing an efficient and feasible technical approach for high-precision remote sensing monitoring of invasive plants in coastal wetlands.

In the northwestern arid areas with severe shortage of water resources, the comprehensive use of recycled water is one of the important means to effectively alleviate the shortage of water resources. For Yinchuan City, which is relatively rich in lake wetland resources, it is of great significance to carry out ecological rehydration of natural rivers and lakes, but the ecological risks of recycled water used for ecological rehydration of rivers and lakes cannot be ignored. Taking Yuehai Lake, a typical lake in Yinchuan City, as the research object, through indoor simulation experiments, the effects of different proportions of recycled water replenishment on water quality and microorganisms of Yuehai Lake were studied. The research results showed that with the increase of the proportion of recycled water replenishment, the concentrations of total nitrogen, nitrate nitrogen and total phosphorus increased significantly, but gradually decreased in the later stage of the experiment. Dissolved oxygen as a whole showed a downward trend, while the chemical oxygen demand showed the characteristics of first decrease, then rise and then decrease. The turbidity first decreased and then increased, and pH gradually stabilized after a sharp rise in the middle of the experiment, and the electrical conductivity was on the rise and there was a stratification phenomenon. Amorphous phylar was the dominant phylar, and its proportion increased significantly with the increase of the proportion of rehydration and the hydration time. The proportion of mycobacterium phyllus and the wart microphyll gradually decreased. When the ratio of recycled water replenishment was 50%-60%, although the concentration of total nitrogen and total phosphorus increased in the early stage, it decreased rapidly in the later stage under the action of microbial assimilation and self-cleaning. The dissolved oxygen stabilized above 6 mg/L, and the turbidity and chemical oxygen demand changed the least. At the same time, the richness and diversity of microbial species under this ratio were high, the proportion of metamorphic phylar was maintained at about 85%, and the community structure was rich and stable. Redundancy analysis showed that nitrate nitrogen, pH and total phosphorus had a significant impact on the microbial community structure, but the three fluctuations were the weakest and the ecological position was the most stable in the 50%-60% groups. Comprehensive water quality safety and biodiversity, the ratio of 50% to 60% recycled water replenishment is the optimal range for the ecological replenishment of Yuehai Lake, which can realize the efficient recycling of water resources while ensuring the landscape function.

Wetland transformations emerge from complex human-natural interactions, exerting a profound influence on wetland ecosystem service values and regional sustainability. This investigation employed multi-temporal Landsat imagery (7 epochs) and field datasets from 1991 to 2020, supplemented with socioeconomic records from the Changsha City Statistical Yearbook, to analyze wetland area changes and quantify ecosystem service values (ESVs). The study systematically examined drivers of area changes through integrated analysis of socioeconomic indicators (population growth, GDP expansion, urbanization rate, agricultural land use) and environmental parameters (mean annual temperature, precipitation patterns). Key findings revealed persistent declines in both wetland extent and associated ESVs over three decades. Total wetland area decreased by 17.6% (51 000 to 42 000 hm²), predominantly through pond wetland conversion. Concurrently, ESVs declined by 18.3% (2.02 to 1.65 billion Yuan), with regulatory services constituting the largest contribution and provisioning services the smallest. Among wetland types, pond wetland demonstrated the highest service value, followed by riverine wetland, with lake-reservoir wetland exhibiting the lowest valuation. Regression analysis identified significant negative correlations (p<0.05) between total wetland area and key socioeconomic drivers (population density, GDP growth, and agricultural expansion). These relationships highlight the dominant role of anthropogenic pressures over natural climatic factors in wetland transformations, particularly the conversion of peri-urban wetland ecosystems to meet demands for urban expansion and agricultural development.

The central region of Shanxi Province, located in the semi-arid Loess Plateau of northern China, is characterized by severe spatial and temporal disparities in freshwater resource distribution. Rapid urbanization, intensive agricultural activities, and climate variability have exacerbated water scarcity, leading to overexploitation and degradation of aquatic ecosystems. To systematically evaluate the ecological health of river systems in this region, this study conducted a comprehensive survey of macroinvertebrate communities across three major river basins: the Yellow River Basin, Fenhe River Basin, and Hai River Basins in October 2023. A total of 22 sampling sites were selected to represent diverse hydrological conditions, including headwater streams, mid-reach channels, and downstream zones influenced by human's impact. Standardized kick and sweep hand net sampling was conducted using a Sobol net (mesh size: 500 μm) to collect samples of large invertebrates, which were then identified to the lowest possible taxonomic level. Community structure and biodiversity were assessed using seven biological indices: the Shannon-Wiener Diversity Index (H'), Simpson's Dominance Index (d), Margalef's Richness Index (d_m), Pielou's Evenness Index (J), the Biotic Pollution Index (BPI), the EPT Index (Ephemeroptera, Plecoptera, Trichoptera), and the Percentage of Dominant Taxa. Water quality was classified according to China’s national standards (GB 3838-2002), where Grade I represents clean and Grade V indicates severe pollution. Environmental variables, including dissolved oxygen (DO), chemical oxygen demand (COD), total nitrogen (TN), total phosphorus (TP), pH, and watershed-scale factors, were measured to identify drivers of ecological degradation through Redundancy Analysis (RDA). Key findings revealed significant spatial heterogeneity in water quality and biotic responses. A total of 128 macroinvertebrate species from 48 families were identified, dominated by pollution-tolerant taxa (79.69%). The most abundant species included Paraleptophlebia sp. (Ephemeroptera), Caenis sp. (Ephemeroptera), and Cryptochironomus rostratus (Chironomidae), which collectively accounted for 53.4% of total abundance. Sensitive EPT taxa, such as Baetis sp. and Hydropsyche sp., were largely absent from urbanized and agricultural zones. 38.9% of sites were classified as Grade IV (moderate pollution), with elevated COD and TN linked to industrial discharges in Yellow River Basin. 65.6% of sites fell into Grades III–IV (light to moderate pollution) in Fen River Basin, correlating with high agricultural runoff. Upstream regions exhibited the best water quality in Hai River Basin, with only 7.5% of sites categorized as Grade V (heavily polluted), primarily near coal mining areas. RDA ordination explained 68.3% of cumulative variance, with the first axis (39.8%) strongly associated with organic pollution. Agricultural non-point source pollution and population density were key anthropogenic stressors. These results underscore the critical role of organic pollutants and land-use practices in shaping aquatic ecosystem health. To address these challenges, we propose a dual strategy: Immediate Mitigation: Prioritize wastewater treatment upgrades in urban clusters and implement precision agriculture technologies (e.g., controlled-release fertilizers) to reduce nutrient runoff. Long-term Monitoring: establish a basin-wide biomonitoring network using EPT taxa as bioindicators, supplemented by remote sensing for real-time pollution tracking. This study provides a scientific foundation for adaptive management in semi-arid regions, emphasizing the need to reconcile economic development with ecological resilience in the Loess Plateau. Future research should explore seasonal variability in macroinvertebrate assemblages and integrate climate projections to forecast long-term ecosystem trajectories.

To investigate the community structure of macrozoobenthos in Yilong Lake and its response to aquatic environmental changes, sampling and identification of macrozoobenthos were conducted in the wet season (July) and the dry season(November) of 2023, with 10 water quality parameters measured simultaneously to analyze the relationship between water quality indicators and the macrozoobenthic community.The results indicate that a total of 64 macrozoobenthic species were identified from Yilong Lake, belonging to 5 phyla, 16 families, and 33 genera.The dominant groups were chironomid larvae (32 species, 50%), oligochaetes (11 species, 17.19%), and crustaceans (7 species, 10.94%), followed by other aquatic insects (9 species, 14.06%, excluding chironomids), mollusks (3 species, 5%), and others (2 species, 3%). The top three dominant species were Limnodrilus hoffmeisteri, Tanypus sp. A, and Macrobrachium superbum.The average density and biomass of macrozoobenthos were 313.72 ind./m² and 51.73 g/m², respectively. Non-parametric tests revealed no significant seasonal differences in density or biomass of various macrozoobenthic groups between the wet and dry seasons, though both total density and biomass were higher in the wet season than in the dry season. Spatially, the density was significantly higher in the central lake area more than in the littoral zone, whereas biomass showed the opposite trend. The Shannon-Wiener diversity index and Margalef richness index of the macrozoobenthic community were significantly lower in the wet season than in the dry season, while no significant difference was observed in the Pielou evenness index. Redundancy analysis (RDA) and Monte Carlo permutation tests revealed that turbidity (f=2.6, p<0.010) was the primary factor influencing macrozoobenthic community variation in the wet season, with water temperature (f=3.4, p=0.040) as a secondary factor. In the dry season, pH (f=4.2, p=0.018) emerged as the dominant influencing factor.

Benthic macroinvertebrate communities are key bioindicator taxa for the health of mangrove ecosystems, as their community structure and function can directly reflect habitat quality and ecological integrity. To understand the characteristics of large benthic invertebrate communities in the Guangdong Neilingding Island-Futian Mangrove Nature Reserve, a survey of benthic macroinvertebrates was conducted in September 2023. Samples of benthic macroinvertebrates and water quality were collected from Fengtang Estuary, Shazui Wharf, Bird Watching Pavilion, No. 1-10 saltwater fish ponds, and freshwater ponds for analysis. The results showed that a total of 42 species belonging to 6 classes were identified, predominantly from the phyla Mollusca and Arthropoda. In the mangrove area, the abundance and biomass of benthic macroinvertebrates ranged from 111.93 to 469.04 ind./m² and 57.33 to 1150.05 g/m², respectively, with the highest values recorded at the middle and high tidal zones of the Bird Watching Pavilion. In the gei wai fish ponds, the abundance and biomass varied from 37.31 to 389.09 ind./m² and 0.30 to 605.65 g/m², respectively, with the peak values observed in Pond 9 and Pond 7. The dominant species in the mangrove area included Nephtys oligobranchia, Neanthes glandicincta, and Potamocorbula laevis, while those in the gei wai fish ponds were Tarebia granifera, Sermyla riqueti, and Angulyagra polyzonata. The Abundance-Biomass Comparison (ABC) curve indicated that the benthic macroinvertebrate community in the reserve was structurally stable and less disturbed by external factors. Based on biodiversity indices, the Shannon-Wiener diversity index, Margalef richness index, and Pielou evenness index in the mangrove forest area were 2.42-4.18, 1.36-3.81, and 0.86-0.95, respectively, whereas those in the gei wai fish ponds were 1.15-3.32, 0.71-2.87, and 0.72-0.93, respectively. Significant differences were detected in community composition between the mangrove forest area and gei wai fish ponds (p<0.01), the mangrove forest area exhibited higher species number, abundance, biomass, and biodiversity. Environmental factors exerted varying degrees of influence on the benthic macroinvertebrate community, with petroleum pollutants, salinity, and electrical conductivity being the main driving factors. Specifically, salinity showed a significant negative correlation with the Shannon-Wiener diversity index, richness index, and evenness index (p<0.05). Combined with historical data and previous research findings, this study demonstrated that the biodiversity and biomass of benthic macroinvertebrates in Futian Mangrove Wetland have been significantly improved after more than two decades of protection and management.

To safeguard water quality for ecological water replenishment in the Yongding River and address the potential water quality non-compliance issues caused by direct recycled water discharge, a subsurface flow constructed wetland was established within Beijing Yongding River Leisure Forest Park, aiming for advanced purification of recycled water. Based on daily water quality monitoring data throughout a complete water supply period (Mar. to Nov.) in 2022, this study systematically evaluated the continuous purification efficiency of the subsurface flow constructed wetland on recycled water. Results demonstrate that the subsurface flow constructed wetland effectively purified the quality of recycled water, with chemical oxygen demand (COD) and pollutant concentrations, including suspended solids (SS), total nitrogen (TN) and total phosphorus (TP), were significantly reduced (p<0.001) compared to the influent. The treated effluent water also exhibited greater stability. The removal rates for SS and TP were particularly high, reaching 68.35% and 57.78%, respectively, while removal rates for COD and TN were 29.49% and 15.29%, respectively. In terms of purification mechanisms, pollutant removal in this system primarily relied on filtration and adsorption by the substrate, whereas plant uptake and microbial decomposition played a more limited role. To address existing issues, future improvements can prioritize the construction of surface flow wetland units to optimize hydraulic condition, the selection of highly efficient purifying plants to establish diverse communities, and the inoculation of functional microorganisms to enhance biodegradation performance. These multidimensional strategies will strengthen the water purification capacity of the subsurface flow constructed wetland, enabling it to better support ecological restoration of the Yongding River.

Mangroves are a pivotal component of blue-carbon ecosystems, and the stability of soil organic carbon (SOC) in these systems exerts a critical control on their carbon-sink function. Along a latitudinal gradient from Fujian to Guangdong and Hainan, we collected surface (0–20 cm) and subsurface (40–60 cm) soils dominated by two representative mangrove species, Kandelia obovata and Avicennia marina. After 90 d of laboratory incubation, cumulative SOC mineralization (used as a proxy for SOC stability) was measured and related to different soil carbon fractions. Results showed no significant difference in cumulative SOC mineralization among latitudes or plant communities. SOC in deeper layers was more stable than in surface layers. Fine-particle content was positively correlated with the proportion of mineral-associated organic carbon (MAOC) to SOC, whereas the MAOC/SOC ratio was negatively correlated with cumulative mineralization. On average, MAOC accounted for 54.00% of SOC, whereas microbial residue carbon (MRC) represented only 14.27%. SOC was significantly correlated with both particulate organic carbon (POC) and MAOC, but the relationship was stronger for POC. These findings suggest that SOC stability in mangroves is primarily governed by soil texture, and the influence of latitude and community type requires further investigation. Microbial residue carbon is unlikely to be the main source of stable MAOC, whereas the labile POC fraction may be a key driver of SOC accumulation in mangrove soils.

Compensatory growth following disturbance is a prevalent phenomenon in clonal plants within natural ecosystems, and the bud bank serves as a crucial source for population regeneration in clonal plants. This study focused on Carex brevicuspis, a dominant species in the Dongting Lake wetlands, and established two experimental groups (severe clipping and mild clipping) along with one control group. By collecting and analyzing data on growth performance, regenerative potential, and reproductive strategy, the responses of the C. brevicuspis population and its bud bank to different clipping intensities were investigated. The results demonstrated that, clipping led to a decline in the growth performance of the C. brevicuspis population. Compared with the control group, severe clipping significantly reduced plant density, height, aboveground biomass, and belowground biomass, while mild clipping significantly decreased plant height and aboveground biomass. Clipping impaired the regenerative potential of the C. brevicuspis population; basal bud density was significantly reduced under all clipping treatments, and apical bud density was also significantly decreased following severe clipping. Mild clipping had no effect on the reproductive strategy of C. brevicuspis, whereas severe clipping altered its reproductive strategy, shifting it from guerrilla-type growth to phalanx-type growth. Overall, the C. brevicuspis population exhibited a certain degree of resistance to clipping stress; however, excessively high clipping intensity adversely affected the regenerative capacity of the C. brevicuspis population. This study provides a scientific basis for plant species conservation, waterbird habitat management, and the development of ecological restoration strategies in the context of habitat changes in the Dongting Lake wetlands.

As ecosystems with the highest biodiversity and ecological roles in the world, wetlands are confronted with a growing number of environmental pollution problems, especially heavy metal contamination, which has emerged as a crucial area of study. As a result, it has become essential to preserve wetland ecosystems. Plants, the fundamental component of constructed wetlands, are extensively utilized in the treatment of heavy metals in effluent, industrial wastewater, and residential sewage since they are low cost, low risk of secondary environmental damage, and superior ecological benefits for the environment. They play an important role in the purification of water bodies. Applying phytoremediation technology effectively requires an understanding of the mechanisms behind plant-based heavy metal remediation. This is crucial for improving the effectiveness of heavy metal pollution remediation in wetlands and lowering ecological concerns. This study examines recent local and international studies on the use of wetland plants for heavy metal pollution remediation. The importance of phytoremediation in wetland restoration is highlighted as it explores the capacities and processes of common wetland plants in the buildup and removal of heavy metals. Research shows that common plants in China and overseas, such as Phragmites australis, Typha orientalis, Thalia dealbata, and Myriophyllum verticillatum, have potent remediation abilities for wetland soils contaminated with heavy metals. Through a multitude of processes, including the release of root exudates (Res) into the rhizosphere environment, the formation of iron plaques on root surfaces, and radial oxygen loss (ROL), plants improve their capacity to accumulate heavy metals. Specifically, by releasing root exudates and causing radial oxygen loss, plants change the rhizosphere's pH, redox potentials, and microbial activities. It alters the solubility and mobility of heavy metals and encourages plant absorption of them. In addition, plants can form iron plaques on their roots to fix heavy metals and prevent them from entering the plant and causing toxicity. Heavy metals enter plant tissues, bind to phytochelatins to form heavy metal-phytochelatin complexes, and are subsequently carried into vacuoles by specific metal transporters, among which are cation diffusion facilitators (CDF), metal transporter P1B-ATPases, and iron-regulated transporter-like protein (ZIP). Furthermore, by controlling the activity of antioxidant enzymes like superoxide dismutase (SOD), peroxidase (POD), ascorbate peroxidases (APX), and catalase (CAT), plants can be used to increase their resistance to heavy metal toxicity under heavy metal stress conditions. This provides an efficient antioxidant defense mechanism that eliminates an excessive amount of reactive oxygen species (ROS), reducing the oxidative harm that reactive oxygen species inflict. Future research should focus on the application of genetic engineering and integrated remediation technologies that will enhance both the effectiveness of phytoremediation and its practicality when dealing with wetland heavy metal contamination.

The incubation period is a key stage for bird breeding. Comparative studies on the incubation period behaviors of Red-crowned Crane (Grus japonensis) parental birds at different breeding start times is helpful to reveal the different behavioral countermeasures, and survival and reproductive status in different phenological periods, which is a positive significance for crane conservation. From March to June 2023, a comparative study on the incubation period behavior at different breeding start times of parental birds was carried out in the Zhalong National Nature Reserve, Heilongjiang, China. 16 parental birds were divided to early incubation group (March, n=9) and late incubation group (April and May, n=7) two groups according to the start time of breeding. The incubation period behavior was approximately 33 days. Per parental birds was observed and compared by all occurrence sampling and instantaneous scan sampling methods. The results showed that the time for female and male parental birds to brooding eggs, resting, leave the nest, preening, wandering, cooling eggs, chirping to warning decreased successively and showed the same pattern in the early incubation group and the late incubation group. The proportion of female and male parent bird behavior times to the total day time were 49.04%, 46.22% (early) and 51.76%, 42.42% (late) for brooding eggs, 22.51%, 28.01% (early), and 22.66%, 26.92% (late) for resting, 20.16%, 18.99% (early), and 20.89%, 26.56% (late) for leaving the nest, and 8.29%, 6.78% (early), and 4.69%, 4.10% (late) for the other five behaviors, respectively. There were no significant differences (p>0.05) in times of brooding eggs, cooling eggs, chirping and resting between females and males, but there were significant differences (p<0.05) in times of leave the nest, wandering, preening and warning. Between the early incubation group and the late incubation group, there were no significant differences (p>0.05) in times of brooding eggs, cooling eggs and chirping, However, times of warning, leave the nest, wandering and preening in the late incubation group were significantly lower than those in the early incubation group (p<0.05). The resting number of female birds in the late incubation group was significantly lower than that in the early incubation group (p<0.05) and there was no significant difference compared to male birds (p>0.05). The male and female parental birds of Red-crowned Crane adapted to the phenological differences in different incubation periods by coordinating the countermeasures of each other’s survival behavior times and frequency. However, the average incubation task sharing pattern, the gender differences and the reproduction investment were not affected by the difference in incubation initiation time.

Under the background of environmental protection, constructed wetland, an ecological technology, is widely used in advanced treatment and ecological purification of various surface water bodies because of its low carbon, low consumption and high efficiency. Plants are considered to be important parts of constructed wetlands and play an important role in the process of water purification. Due to the growth characteristics of wetland plants, if the withered wetland plants can not be harvested in time, they will lead to secondary pollution, and even cause wetland blockage, which will affect the stable operation of wetland system. This paper summarized the influence of plant harvesting on the operation effect of constructed wetland system, analyzed the mechanism of plant harvesting affecting pollutant removal, and finally summarized the harvesting management strategies of different kinds of plants. This paper makes up the blank of this part through narration, which will better guide the harvesting process of constructed wetland plants. The seasonal fluctuation of plant harvesting on water quality is significant. Harvesting in spring and summer can stably improve the removal effect of pollutants such as chemical oxygen demand and total nitrogen in the system, while harvesting in autumn and winter is beneficial to the removal of total phosphorus and ammonia nitrogen, but the impact on chemical oxygen demand and total nitrogen fluctuates greatly. In terms of plant species, harvesting submerged plants is more conducive to removing four conventional pollutants (chemical oxygen demand, total nitrogen, total phosphorus, and ammonia nitrogen) compared to emergent plants, which facilitates better purification of constructed wetland water bodies. At the same time, through the second excavation of the article, it is found that there is a certain correlation between wetland plant species and seasons during harvesting. In addition, harvesting not only directly affects the productivity and biological characteristics of plants, but also indirectly affects the physical and chemical environment and microbial metabolism process of wetlands by changing the oxygen secretion level of plant roots and the activity of substrate enzymes, thus affecting the plant-microorganism-substrate coupling effect and the geochemical cycle process of pollutants, which makes the change of water purification efficiency in constructed wetlands. The influence of plant harvesting on the operation of constructed wetland mainly depends on harvesting time, harvesting mode, harvesting frequency, harvesting degree and plant species. When harvesting plants, appropriate harvesting strategies should be selected according to plant types and actual conditions of constructed wetlands, striving to achieve the optimal solution.

Under the background of global change, to explore the mechanism of wetland vegetation response to nitrogen deposition, we selected Deyeuxia purpurea which is one of the dominant plants of Sanjiang Plain Wetland as the research object, through controlled experiments to study the effects of nitrogen addition level and nitrogen addition time on its functional traits, asexual reproduction and biomass allocation. In this controlled experiment, five nitrogen addition levels were set, CK[0 g/(m²·a)], N1[2 g/(m²·a)], N2 [4 g/(m²·a)], N3[6 g/(m²·a)]and N4[8 g/(m²·a)], and the experimental period was 2 years. The research results indicated that nitrogen addition time, nitrogen addition level and their interaction had extremely significant impacts on plant height, base diameter, and number of branches of D. purpurea (p<0.01). Nitrogen addition increased the number of branches, decreased the leaf length, and significantly reduced the plant height and base diameter of D. purpurea in the first year (p<0.01), while showed opposite trends in the second year. Nitrogen addition time and levels had significant effects on the number of dormant buds and sprouting buds at the tillering nodes of D. purpurea (p<0.01), and their interaction had extremely significant effects on the number of established individuals, the number of elongating rhizome branches, and the number of sprouting buds of rhizomes (p<0.01). Nitrogen addition increased the number of established individuals, the number of sprouting buds at tillering nodes, and the number of dormant buds, but decreased the length and number of elongating rhizome branches. Total biomass, above-ground biomass, and below-ground biomass of D. purpurea gradually increased with the increase of nitrogen addition concentration, and the results of the second year were significantly higher than those of the first year (p<0.01). The allocation proportion of root and leaf biomass gradually increased, while the allocation proportion of stem biomass decreased. Our study demonstrated that the addition of nitrogen increased the number of branches, tillering buds, sprouting buds of rhizomes, and the number of established individuals of D. purpurea, decreased the leaf length, the number and length of elongating rhizome branches, and promoted the biomass accumulation. At nitrogen addition levels of 6 g/(m²·a) and 8 g/(m²·a), and with an additional period of two years, it effectively regulated the growth and asexual reproduction of D. purpurea. The results showed that D. purpurea through an ‘intensive’ growth strategy to expand its population number under the the nitrogen addition background.

Qinghai Province is one of the main summering and breeding grouds of Black-necked Cranes (Grus nigricollis), a national first-class protect species in China and a Near Threatened (NT) species on the IUCN Red List. However, systematic and comprehensive research on the spatiotemporal distribution of this high plateau crane species in Qinghai remains inadequate. To address this gap, we integrated multi-source data to clarify its spatial and temporal distribution patterns and potential habitat, providing a scientific basis for targeted conservation. A total of 1 178 valid distribution points from field research and citizen science platforms were used to predict habitat suitablity of Blanc-necked Crane by conducting MaxEnt model. Meanwhile, we used the point density analysis tool in ArcMap (with a 100 km radius) to characterize temporal distribution dynamics. The results show that spatially, suitable habitat of Black-necked Cranes in Qinghai Province are mostly distributed along rivers and lakes, specifically include areas around Qinghai Lake, south slope of the Qilian Mountains, upper reaches of the Yellow River in eastern Qinghai Province, Sanjiangyuan area and the east extension of Qaidam Basin. Total potential suitable habitat is 116 831 km², it accounts for 16.7% of the total area of Qinghai Province, among which there are 2 626.6 km² of highly suitable habitat, accounting for 0.4% of the area of the whole province. Gangca county, Qilian county, Haiyan county, Tianjun county, and Gonghe county are the top five administrative regions with the largest highly suitable areas, each exceeding 300 km². Temporally, April to September constitutes the main residence period for Black-necked Cranes in Qinghai. The surrounding areas of Qinghai Lake, Qilian Mountains and Yushu are the three areas with the highest concentration of records. The distribution from July to August is the most scattered. Notably, 18 records (including single individuals and small groups) confirm that some cranes remain in Qinghai during the overwintering period (December–February), primarily in the Qinghai Lake vicinity and the Sanjiangyuan area. We considered this this previously unreported phenomenon may relate to the physical condition of individuals, local environmental conditions, Climate change, and population migration patterns. Jackknife test results revealed that altitude (contribution rate 31.8%), annual precipitation (18.8%), distance from rivers (16.3%), slope (8.2%), and land cover (7.7%) are the five most influential environmental factors shaping habitat suitability. Annual precipitation positively correlates with habitat suitability, likely by regulating wetland area and water depth. Wetlands and water bodies are the most preferred land cover types, while artificial surfaces (including farmland) also show relatively high suitability, reflecting the cranes’ adaptation to foraging on residual crops. Notably, highly suitable habitats overlap significantly with areas of high grazing intensity, highlighting the need for in-depth research on the coexistence mechanisms between grazing activities and cranes. Although there are potential suitable habitat in every county of Qinghai Province, the black-necked crane still faces multiple conservation challenges: only 28.06% of suitable areas are within existing protected areas; habitat degradation and fragmentation persist due to climate change and anthropogenic activities, and migration connectivity is threatened by power line collisions, a major cause of juvenile mortality. Additionally, the functional roles of most habitats (e.g., stopover, roosting or breeding sites) remain uncharacterized, limiting the effectiveness of conservation measures. To address these issues, we recommend to carry out continuous monitoring based on the spatiotemporal distribution of Black-necked cranes, clarify the functions of each distribution area, build a migration network and identify problems and barriers in the network.

To comprehend the composition of plankton community in the Qingtu Lake wetland and its correlation with environmental factors, 14 sampling points were set up for plankton surveys in May (spring), August (summer), and November (autumn) 2021. The results showed that a total of 114 species of phytoplankton were identified from 64 genera and 7 phyla, predominantly consisting of bacillariophyta (57.02%) and chlorophyta (24.56%). The prevailing species throughout the year were Navicula radiosa, Navicula gregaria, Synedra acus and Synedra ulna. And 48 species of zooplankton were identified from 37 genera and 5 categories, with rotifers (50%) and protozoa (33.33%) being the predominant groups, and rotifers being the primary dominant group. The abundance and biomass of plankton exhibited substantial seasonal fluctuations. The annual average abundance and biomass of phytoplankton were 5.88×10³ ind./L, and 2.52×10⁻² mg/L, respectively, with both peaking in summer. The annual average abundance and biomass of zooplankton were 34.87 ind./L and 21.24×10⁻² mg/L, with peaking in autumn and summer, respectively. The results of the comprehensive assessment using Shannon-Wiener diversity index, Margalef richness index, and Pielou evenness index indicated that the water quality of the Qingtu Lake was classified as unpolluted to moderately polluted. Redundancy analysis indicated that the primary environmental factors influencing the distribution of phytoplankton communities were the levels of dissolved oxygen, ammonia nitrogen, pH, and total nitrogen. The key environmental factors influencing the distribution of zooplankton communities were the levels of dissolved oxygen, total nitrogen, conductivity, and ammonia nitrogen. Ecological water transport is an effective measure to maintain plankton diversity in the Qingtu Lake wetland, and the research results can provide data support for ecological restoration and early warning of monitoring in the Qingtu Lake wetland.

Riverine wetlands underpin regional socio-economic development by sustaining critical ecosystem functions and services, including water provision and regulation, ecosystem maintenance, and biodiversity conservation. Accordingly, a rigorous assessment of riverine wetland ecosystem health is essential for guiding rational water-resource utilization and supporting sustainable regional development. Anchored in the concept of ecological integrity, this study developed an integrated framework for evaluating riverine wetland health through the systematic classification, reorganization, and synthesis of widely used river-health indicators into a coherent, multi-dimensional index system. The framework comprises three complementary indicator domains, aquatic biological, physical (habitat), and chemical (water-quality) indicators, designed to capture biological community condition, habitat structure and stability, and the physicochemical environment, respectively. To ensure that the relative diagnostic value of these domains was explicitly represented in the assessment, the Analytic Hierarchy Process (AHP) was used to derive criterion-level weights. The weighting scheme assigned the highest importance to aquatic biological indicators, followed by physical indicators, with chemical indicators weighted lowest, reflecting the premise that biotic assemblages and habitat attributes often integrate cumulative environmental effects and could be more responsive to disturbance than routine chemistry at reach-to-river scales. Because the differential importance of individual metrics within each domain is difficult to determine objectively, equal weights were assigned to metrics within the same domain. The finalized framework includes 18 metrics, encompassing attributes of benthic macroinvertebrate communities, channel morphology and riparian condition, and key water-quality variables (e.g., nutrients and dissolved oxygen). Metric scores were standardized and aggregated to generate an integrated health index, which classified riverine wetland condition into five grades ranging from ‘very poor’ to ‘healthy’. The framework was applied to riverine wetlands in the southern section of the Gaoligong Mountains, Yunnan Province, China. Field investigations were conducted in November 2018, integrating assessments of channel form and riparian habitat, measurements of water physicochemical properties, and standardized collection and identification of benthic macroinvertebrates. Application of the integrated index indicated that the study area could be partitioned into two major basins, the Dulong River Basin and the Nu River Basin, both of which were evaluated as healthy at the basin scale. At the river scale, five of the six investigated rivers were classified as healthy, whereas one river was rated good. Relative to previous assessments conducted in the same region, the restructured and reweighted framework yielded results judged to be more reasonable, with improved interpretability and greater sensitivity. By prioritizing biological integrity while retaining essential habitat and water-quality information for diagnosis and management, this framework provides a scientifically robust tool for riverine wetland health evaluation, conservation and restoration planning, and evidence-based water-resource management.

Tussock wetlands, serving as a unique landscape within marsh wetlands and performing vital ecological functions, have become a research hotspot due to their distinctive environmental heterogeneity and the influence of hydrological conditions. The formation of tussock wetlands is closely linked to hydrological conditions, and changes in these conditions also affect the development and evolution of tussock wetlands. Hydrological conditions exert a direct impact on tussock plants. Through flooding conditions, they directly influence the species distribution, physiological traits, morphological structure, growth status, and biomass of tussock plants, as well as the characteristics of tussock mounds such as height, basal area, mound shape, distribution density, and spacing. This affects the feedback between tussock plants and soil, thereby influencing the formation and evolution processes of tussock wetlands and the performance of their functions. Hydrological conditions drive the formation of unique micro-topographic features in tussock wetlands and generate environmental heterogeneity, resulting in markedly different hydrological environmental characteristics on-mound versus inter-mound. Hydrological conditions impact the carbon and nitrogen cycling processes and the functioning of their "source" and "sink" roles in tussock wetlands by regulating plant-soil feedback and microbial activity. With changes in natural conditions and increasing anthropogenic disturbances, structural damage and functional degradation of tussock wetlands are intensifying annually. How to fully utilize the role of hydrological conditions to accelerate the restoration process of tussock wetlands and promote the restored wetlands to fully realize their "source" and "sink" functions is key to tussock wetland restoration. This paper summarizes the response patterns of tussock wetlands to hydrological conditions, analyzes the existing restoration methods for tussock wetlands and their shortcomings, and proposes measures utilizing hydrological response patterns to promote the restoration of tussock wetland structure and function, aiming to provide references for the conservation and restoration of tussock wetlands.

Spartina alterniflora is a widely recognized invasive species that poses significant threats to native ecosystems. Its successful invasion is closely linked to its allelopathic effects, which involve the release of chemical compounds that influence the growth and physiological processes of neighboring organisms. This review comprehensively summarizes the classification of allelochemicals produced by Spartina alterniflora and explores the multiple mechanisms through which its allelopathic effects operate. The allelopathic substances secreted by Spartina alterniflora include organic acids, flavonoids, coumarins, alkaloids, and other secondary metabolites, primarily released through root exudates, leaching, and decomposition of plant residues. These compounds interfere with nutrient and water uptake in native plants by disrupting root function, thus limiting their access to essential growth resources. Moreover, Spartina alterniflora allelochemicals inhibit photosynthesis and respiration by damaging chloroplast ultrastructure and reducing photosynthetic pigments, stomatal conductance, and transpiration rates in native plants such as mangroves and herbaceous species. Additionally, these chemicals affect enzyme activities and cell membrane permeability, altering antioxidant enzyme systems (e.g., superoxide dismutase and peroxidase) and increasing lipid peroxidation markers, thereby compromising plant physiological function. The allelopathic effects extend beyond plants, impacting soil microbial communities by reducing the colonization of beneficial mycorrhizal fungi and altering microbial biomass and nutrient cycling processes, particularly carbon and nitrogen dynamics. These microbial changes negatively affect soil health and nutrient availability, further influencing plant community structure.The invasion of Spartina alterniflora also disrupts benthic animal communities in coastal wetlands, leading to declines in species diversity and richness of mollusks and nematodes. This is partly attributed to chemical changes in the sediment environment induced by allelochemicals released into the rhizosphere and litterfall, which alter food web dynamics and nutrient cycling in these habitats.Interestingly, Spartina alterniflora exhibits autotoxicity, where some allelochemicals produced inhibit its own seed germination and seedling growth, affecting its population dynamics. However, most research has focused on its heterospecific allelopathic interactions, and further studies are required to elucidate the mechanisms and implications of its autotoxicity.The allelopathic interaction between Spartina alterniflora and native plants is bidirectional. Certain native species such as Phragmites australis (common reed) and mangroves release compounds that suppress Spartina alterniflora growth, indicating complex chemical interactions that could be leveraged for ecological management. In addition to ecological impacts, Spartina alterniflora allelochemicals have practical applications. Extracts from this species demonstrate inhibitory effects on harmful algal blooms, such as Microcystis aeruginosa and Prorocentrumdonghaiense, through oxidative stress induction and disruption of photosynthetic systems. Moreover, flavonoids isolated from Spartina alterniflora possess anti-inflammatory properties and have been explored for cosmetic applications, suggesting potential economic value.Future research should broaden the scope to include effects on lower plants, fungi, soil biochemical properties, and animals, and investigate environmental factors influencing allelochemical production and release. Advanced analytical methods are needed to isolate and identify allelochemicals, while genetic and molecular studies could clarify regulatory mechanisms. Exploring integrated management strategies combining biological, chemical, and physical methods is essential to control Spartina alterniflora invasions while harnessing its beneficial properties. Overall, this review provides a comprehensive understanding of the allelopathic roles of Spartina alterniflora in invaded ecosystems, offering critical insights for ecological restoration and invasive species management.

In recent years, the rapid expansion of industrialization and urbanization in the coastal zones of Jiangsu Province has led to the extensive discharge of polycyclic aromatic hydrocarbons into river systems flowing into the sea, significantly accelerating the degradation of estuarine and nearshore ecosystems. The concentrations of polycyclic aromatic hydrocarbons were determined in two sediment cores (sediment core 1 and sediment core 2) from the Sheyang River Estuary in Yancheng City, Jiangsu Province, China. The characteristics of vertical distributions, sources, and ecological risk level was analyzed, and explored the correlation between pollution of polycyclic aromatic hydrocarbons and human activities. These can provide essential scientific support for pollution control and environmental management in estuarine zones of coastal cities. The average total concentrations of 15 kinds polycyclic aromatic hydrocarbons in sediment core 1 and sediment core 2 were 122.21 ng/g and 141.88 ng/g, respectively. The average concentrations of seven carcinogenic polycyclic aromatic hydrocarbons were 66.68 ng/g and 72.45 ng/g, accounting for 52.77% and 47.83% of the total concentrations of polycyclic aromatic hydrocarbon load, respectively. High molecular weight polycyclic aromatic hydrocarbons dominated the composition, comprising 79.49% in sediment core 1 and 75.37% in sediment core 2. Among the 15 kinds polycyclic aromatic hydrocarbon, chrysene contributed the largest proportion, accounting for 15.00% and 13.30% in sediment core 1 and sediment core 2 respectively. The vertical distribution of the total concentrations of 15 kinds polycyclic aromatic hydrocarbons exhibited a stagewise increasing trend, which closely corresponded with historical variations in the discharge volume of the Sheyang River Sluice, regional industrial development, and the implementation of environmental policies. Source apportionment revealed that the major contributors were vehicle emissions (45.00%), combustion of coal and natural gas (43.00%), and a mixed source of petroleum leakage and biomass burning (12.00%). Ecological risk assessment indicated relatively low overall risk levels, with benzo[a]pyrene-equivalent toxic risks below 10% in all samples. Redundancy analysis showed that the contamination of polycyclic aromatic hydrocarbons was positively correlated with indicators of industrial and transportation activities, with socioeconomic factors explaining 98.36% of the variation in the contamination of polycyclic aromatic hydrocarbons. Specifically, 3-ring polycyclic aromatic hydrocarbons were positively associated with arable land area and rural population; 4-ring polycyclic aromatic hydrocarbons correlated with urban population and total highway mileage; 5-ring polycyclic aromatic hydrocarbons and 6-ring polycyclic aromatic hydrocarbons were significantly related to the total power of agricultural machinery, and 6-ring polycyclic aromatic hydrocarbons also exhibited a strong positive correlation with urban population. These results suggest that the accumulation of high molecular weight polycyclic aromatic hydrocarbons is primarily driven by urban population growth and vehicular emissions, while agricultural activities are more closely associated with the accumulation of low molecular weight polycyclic aromatic hydrocarbons. Overall, the sedimentary record of polycyclic aromatic hydrocarbons serves as an effective proxy for reconstructing historical trends in regional transportation and agro-industrial activity intensity.

As one of the three major terrestrial ecosystems, wetlands play a critical ecological role in water conservation, climate regulation, and biodiversity maintenance. However, under the dual pressures of climate change and human activities in recent years, existing wetlands are facing increasingly severe threats, particularly from biological invasions that cause significant damage to wetland ecosystems. Cirsium pendulum, a perennial herbaceous plant of the Asteraceae family, characterized by its spiny body, has been extensively observed in the wetlands of the Sanjiang Plain, severely affecting the growth and regeneration of native vegetation. However, research on the ecological effects of C. pendulum spread in wetlands was scarce, which limited the development of effective wetland management strategies. This study, conducted in the natural wetlands of the Sanjiang Plain, analyzed the impacts of different spread levels of C. pendulum on the stability and species diversity of Deyeuxia purpurea communities through field plot surveys. The results showed that C. pendulum spread altered the species composition of D. purpurea communities, the species richness of the heavily spread community decreased from 17 species to only 7 species. Nine species, including Persicaria hastatosagittata, Viola patrinii, and Thelypteris palustris var. pubescens, were absent in heavily spread communities. Compared with non-spread communities, Patrick’s richness index and Shannon-Wiener diversity index were significantly lower in heavily spread communities, while Simpson’s dominance index and Pielou’s evenness index were significantly higher. As the spread intensity increases, the stability of the D. purpurea community showed a downward trend, with the stability of heavily spread communities reduced by 46% compared to the non-spread community. The spread of C. pendulum significantly reduced species diversity and community stability in the D. purpurea community, and caused notable changes in species composition. This study is of great significance for predicting the dynamics of wetland vegetation in the Sanjiang Plain under the context of global change and provides a scientific basis for formulating strategies for wetland vegetation protection and management.

To explore the impact of aeration conditions on greenhouse gas emissions from urban water bodies, this study conducted indoor incubation experiments using the surface sediments from the lakeside zone of Nanjing Binjiang Wetland Park. Four treatment groups including surface aeration, middle-layer aeration, bottom-layer aeration, and a static control group were set up, with aeration heads placed at different depths (1 cm below the water-air interface for surface aeration, 10 cm for middle-layer aeration, and at the water-sediment interface for bottom-layer aeration). During the 45 d experiment, aeration with air was carried out from 12:00 to 15:00 every day. Samples of gas, water, and sediment were collected at 9:00 daily to measure greenhouse gas emission rates, cumulative emissions, and relevant physical and chemical properties. The results showed that in terms of CO₂ emissions, the middle-layer aeration treatment had the most significant inhibitory effect, with the cumulative CO₂ emissions of the surface, middle-layer, and bottom-layer aeration groups being 67.7%, 60.9%, and 76.7% of the control group respectively; for CH₄ emissions, the surface-water aeration treatment led to the highest cumulative emissions, with the cumulative CH₄ emissions of the surface, middle-layer aeration and bottom-layer aeration groups being 197.3%, 106.7%, and 97.7% of the control group respectively; regarding N₂O emissions, middle- layer water aeration significantly increased emissions, with the cumulative N₂O emissions of the surface, middle- layer, and bottom-layer aeration groups being 112.2%, 146.4%, and 81.9% of the control group respectively, while bottom-layer aeration effectively inhibited N₂O emissions. Additionally, different aeration depths significantly affected the physical and chemical properties of the overlying water and the carbon-nitrogen cycling process. The DO concentration decreased with increasing aeration depth, with the bottom-layer aeration group having a significantly lower DO concentration at the end of the experiment compared to the control group. The pH value showed a single-peak trend of first increasing and then decreasing, with the surface-aeration group having the highest pH initially but the control group having a higher pH than the bottom-layer aeration group at the end of the experiment. The DOC and TC concentrations were highest in the control group and lowest in the middle-layer aeration group. In nitrogen transformation, the bottom-layer aeration group had the lowest NH^₄+-N concentration, the middle-layer aeration significantly increased the NO^₃−-N concentration, the TN concentration was lowest in the bottom-layer aeration group with the highest carbon-nitrogen ratio, and the DOM fluorescence analysis showed that the DOM in each treatment group was mainly terrigenous humus with no significant difference in humification degree. This study clarifies the impact of aeration treatment technology on urban landscape water body greenhouse gas emissions, provides an important theoretical basis for urban landscape water body management and carbon emission accounting, helps understand the complex relationships among aeration, water body environment, and greenhouse gas emissions, and is of great significance for formulating scientific urban water body management strategies and reducing urban greenhouse gas emissions. Moreover, the results can serve as a reference for similar studies in other regions, contributing to global climate change mitigation and sustainable urban water resource management.

The Yilong Lake, one of the nine major plateau lakes in Yunnan Province, is currently facing severe threats from water eutrophication. To investigate the adaptive mechanisms of dominant riparian wetland plants under eutrophic conditions, this study focused on reeds (Phragmites australis) and cattails (Typha orientalis) along the lakeshore of the Yilong Lake. We analyzed the characteristics of leaf nitrogen (N) and phosphorus (P) resorption in response to different chemical oxygen demand (COD) gradients: high (45.23-51.47 mg/L), medium (23.04-31.76 mg/L), and low (3.10-18.50 mg/L). Plant and surface water samples were collected synchronously during the peak growing season. The N and P concentrations in both mature and senescing leaves were measured to calculate resorption efficiency. The results showed that the N and P contents in reed leaves declined over the seasons. Leaf N decreased from 24.64 mg/g in spring to 12.25 mg/g in winter, with a reduction of 50.28%, while leaf P peaked in spring (2.70 mg/g), decreased in summer (1.72 mg/g), and reached its lowest in winter (0.61 mg/g). In contrast, cattail leaf N and P initially increased and then decreased with seasonal changes. Leaf N and P were relatively low in spring (20.93 mg/g and 1.84 mg/g), increased in summer (33.56 mg/g and 2.01 mg/g), began to decline in autumn (26.35 mg/g and 1.96 mg/g), and reached the lowest values in winter. The mean N and P resorption efficiencies of reed leaves were 41.93% and 57.85%, respectively, while those of cattail leaves were 42.87% and 63.53%. Across different COD concentrations, the N and P resorption efficiencies were highest under low COD, followed by medium and then high COD. N resorption efficiency differed significantly among COD levels, whereas P resorption efficiency showed no significant variation. Nutrient contents in mature leaves were significantly positively correlated with those in senescent leaves, indicating coordinated nutrient dynamics between the two stages. Moreover, leaf N resorption was significantly negatively correlated with COD concentration, suggesting that higher environmental COD levels reduce leaf N resorption efficiency. Both N and P resorption efficiencies were significantly negatively correlated with nutrient contents in senescent leaves; the greater the nutrient transfer from senescent to young tissues, the longer nutrients are retained within the plant, thereby reducing nutrient leaching during litter decomposition and slowing nutrient loss from the system. This study elucidates the ecological adaptation mechanisms by which wetland plants respond to eutrophication stress through nutrient resorption strategies, providing a theoretical basis for wetland restoration and eutrophication control in the Yilong Lake.

In order to reveal plant community composition, interspecific relationship and community stability in the xerophilic zone, the hygrogenetic zone and the ecotone zone of the Jiangxia Wetland in the middle reaches of the Lhasa River Basin. Community composition, diversity, interspecific association and community stability were analyzed by using 105 herbaceous quadrats. The results showed that there were 40 species of plants belonging to 33 genera and 16 families in the xerophytic zone, the ecotone zone and the hygrophytic zone. The species diversity was highest in the xerophytic zone, followed by the hygrophytic zone, and lowest in the hygrophytic zone. The dominant species in the xerophytic zones were Argentina anserina, Plantago depressa and Cynoglossum amabile. The dominant species in the hygrogenetic zone were Potamogeton natans, Kobresia pygmaea, Carex moorcroftii. The dominant species in the ecotone were K. pygmaea, C. moorcroftii and A. anserina. Overall dominant species were K. pygmaea, Carex sargentiana, C. moorcroftii, A. anserina. There was no significant correlation between the ecotone zone and the hygro-growth zone except for the significant negative correlation between the interspecific associations in the xerophilic zone. X² test, Association Coefficient (AC), Percentage of Common Occurrence (PC) and Point Correlation Coefficient (Ф) test showed that the advantages were not strongly associated with each other, and each species was relatively independent. According to the method of community stability analysis improved by Zheng Yuanrun, it was further concluded that the whole community was in an unstable succession stage. During the process of vegetation protection and ecological governance in the Jiangxia Wetland, priority should be given to species with extremely significant positive correlation between species and a high correlation index, as well as similar environmental adaptability such as Digitaria sanguinalis + Taraxacum mongolicum、Plantago depressa + T. mongolicum、Astragalus strictus + D. sanguinalis mixed plant species such as Ma Tang and others serve as pioneer species. At the same time, based on the ecological characteristics of the plants, it is necessary to select a reasonable combination of species for configuration. When the ecological environment improves in the middle stage of succession, main dominant species such as K. pygmae, K. robusta, A. anserina, etc., can be supplemented to improve the interspecies relationships, increase the stability of the community, accelerate the succession process, and promote the vegetation recovery. These measures will be beneficial for the restoration of the plant community in the Jiangxia Wetland and will contribute to the ecological protection and high-quality development of the Lhasa River Basin. The results can provide important basic data for vegetation restoration of wetland ecosystem in the study area.

Turbidity, as a key optical parameter measuring the scattering and absorption of light by suspended substances (including organic/inorganic particles, phytoplankton, and microorganisms), is one of the core indicators in water quality assessment. In recent years, frequent pollution events in inland water bodies, such as tailings leakage, abnormal turbidity discharges from reservoirs, and industrial runoff, have heightened the need for efficient and accurate water quality monitoring technologies. Traditional turbidity monitoring methods rely on field sampling and laboratory analysis. Although these techniques provide high-accuracy results, they are inherently limited in spatial coverage and temporal frequency, while also being labor-intensive and time-consuming. With the advancement of remote sensing technology, the acquisition of multispectral data via satellite or aerial platforms has emerged as a promising and cost-effective approach for large-scale and periodic turbidity retrieval. Remote sensing-based turbidity estimation offers several advantages, including wide-area coverage, temporal consistency, and the ability to monitor inaccessible regions. A bibliometric analysis of 574 relevant research articles indexed in the Web of Science reveals a clear upward trend in the number of turbidity-related remote sensing studies. Moreover, the diversity of satellite data sources continues to expand. Among them, the Landsat series stands out as the most commonly used due to its 30 m spatial resolution and extensive historical archive spanning over four decades. Other widely adopted sensors include MODIS (Moderate Resolution Imaging Spectroradiometer), which is suited for large-scale observations; MERIS (Medium Resolution Imaging Spectrometer), known for its ocean color-specific spectral bands; and Sentinel-2 MSI and Sentinel-3 OLCI, which strike a balance between spatial and spectral resolution. In terms of retrieval methodologies, early studies primarily employed linear or polynomial regression models. Over time, more sophisticated approaches have emerged, forming a diverse methodological framework. These include empirical models such as single-band threshold methods and band ratio algorithms, semi-analytical models that incorporate water optical properties, and data-driven machine learning algorithms that offer improved flexibility and adaptability. However, accurately estimating turbidity in optically complex inland waters remains a challenge, primarily due to the heterogeneous absorption and scattering effects of different water constituents. Looking forward, future research should prioritize three key directions: integrating multi-source remote sensing data to overcome limitations in spatial and temporal resolution; improving atmospheric correction algorithms to effectively eliminate interference from aerosols and atmospheric particles; and developing classification-based retrieval frameworks that account for the variability of water optical properties across different inland water types. These efforts will collectively enhance the accuracy, robustness, and general applicability of turbidity remote sensing in complex inland aquatic environments.

The ongoing destruction and degradation of wetlands represent a critical ecological and environmental challenge confronting nations globally. As a fundamental strategy for wetland restoration, ecological water replenishment plays a pivotal role in sustaining essential wetland functions. Consequently, accurately assessing ecological water requirements becomes imperative, necessitating consideration of the diverse ecological services and environmental functions provided by specific wetlands. Physical habitat simulation offers a robust methodological approach by quantifying how target protected species respond to alterations in their environment. This technique enables the precise determination of optimal ecological water requirements needed to support the survival and viability of these focal species within wetland ecosystems. This study addresses this need through a focused investigation of the Qilihai Wetland in Tianjin. We developed and rigorously validated a hydrodynamic model to simulate water movement and distribution within this system. Selecting the endangered Siberian Crane (Grus leucogeranus) as our target indicator species, we employed this model to calculate the area of suitable foraging habitat available across a gradient of water levels. Subsequently, we derived the ecological water requirement for the wetland based on the insights gained from these hydrodynamic simulations. Our results demonstrate a clear, non-linear relationship between water level and habitat suitability for Grus leucogeranus. Specifically, the area of suitable crane habitat exhibited a distinct peak, initially increasing with rising water levels before subsequently declining. The maximum suitable foraging area, reaching 1.51 km², was achieved at a water elevation of −3.52 m above sea level. This optimal habitat area constituted 71.99% of the total study region. Based on this critical water level threshold and accounting for necessary hydrological processes, the annual ecological water requirement for the Qilihai Wetland was calculated to be 313.27×10⁴ m³. To consistently maintain habitat conditions that maximize the suitable area for Grus leucogeranus, proactive water management is essential. This involves strategically implementing water replenishment or controlled withdrawal measures, dynamically adjusted in response to prevailing monthly weather conditions and associated evapotranspiration rates.

Wetlands in the source region of the Yellow River are critical for water regulation and serve as a key water supply for the river, playing a strategic role in ensuring the economic, social, and ecological security of the basin. The MSPA-Conefor-MCR model was applied to construct the wetland ecological network in this region, and its functional characteristics were analyzed by quantifying the groundwater recharge volume and value provided by the wetlands. The structural characteristics were evaluated using the connectivity robustness index. The results show that the wetland ecological network in the Yellow River source region comprises of 74 ecological nodes and 670 ecological corridors. Larger wetland patches, excluding water bodies, exhibit higher groundwater recharge volumes and greater recharge value. Among the patches with the highest recharge values, most are located in cold calcareous soils, meadow soils, and black felt soils. Functionally, wetland patches with higher groundwater recharge values are better connected to surrounding wetlands. These patches also have a wider range of ecological resistance values, and the weight sizes of the wetland patches they connect to show some degree of randomness. Structurally, wetland patches in the northeastern and southeastern regions have a stronger potential for connection, while those in the northwestern region have weaker connectivity.

The Liaohe River Estuary Wetland is a critical node along the East Asian-Australasian Flyway, there is an urgent need to harmonize bird conservation and agricultural production. However, a lack of systematic monitoring and analysis limited the exploration of win-win models. This study was conducted in rice paddies with 20% and 10% open water surface (experimental groups) and 0% open water surface (control group) located outside the Liaoning Liao River Estuary National Nature Reserve. Monthly bird surveys were carried out from June 2023 to May 2024. The population density, Shannon diversity index, evenness index, and Simpson index of birds in the experimental and control groups were analyzed, along with their seasonal variations. A green benefit index (GBI) was constructed by combining rice yield per unit area and the input-output ratio to quantify the eco-production synergistic benefits. The results showed that a total of 110 bird species, belonging to 70 genera, 38 families, and 17 orders, were recorded in the rice paddies. Among them, 16 species were national first- and second-class protected wild animals, and 7 ones were listed as globally threatened species according to the International Union for Conservation of Nature (IUCN). The dominant ecological group was waterfowl, and the most abundant IUCN category was summer visitors classified as “Least Concern”. Seasonal variation and the proportion of open water surface in the rice paddies both significantly influenced the community composition. Bird diversity was generally highest in summer across the three types of rice paddies. The Shannon diversity index (p<0.001) and Simpson index of birds in rice paddies with 20% and 10% open water surface were significantly higher than those in rice paddies with 0% open water surface (p<0.05). The rice paddies with 20% open water surface had the highest GBI value of 0.974. These findings demonstrate that creating rice paddies with 20% open water surface can achieve both high economic benefit and high bird diversity. This study quantifies the dual impacts of bird diversity and production benefits in rice paddies with different open water surface proportions in the Liaohe River Estuary Wetland, providing a scientific basis for developing eco-production synergistic management strategies and contributing to a win-win situation of improved agricultural efficiency and biodiversity conservation.

Characteristics of mangrove community structure and species diversity serve as crucial indicators for assessing mangrove ecosystem health. Based on field survey data from three major mangrove areas in Shenzhen, this study comprehensively analyzed and compared community characteristics including arbor species composition, community types, dominant species, and species diversity at a holistic scale, aiming to provide scientific basis for biodiversity conservation and sustainable development of mangroves in Shenzhen. The Futian Mangrove National Nature Reserve, Xiwan Mangrove in Bao'an District, and Luzui Mangrove in Dapeng District represent three typical mangrove distribution areas located in southern, western, and eastern Shenzhen, respectively. To elucidate the community characteristics of Shenzhen’s mangroves, these three representative mangrove distribution areas were selected as study areas. The results demonstrated that in terms of community types, Luzui Mangrove exhibited richer diversity with seven community types, compared to five types each in Futian Mangrove and Xiwan Mangrove. Regarding dominant species, Kandelia obovata, Sonneratia caseolaris, and Sonneratia apetala served as foundational and dominant species widely distributed across all three mangrove areas. Bruguiera gymnorrhiza functioned as an important associated species in Futian Mangrove, while Laguncularia racemosa, Excoecaria agallocha, and Rhizophora stylosa formed locally dominant communities as characteristic species in Luzui Mangrove. Aegiceras comiculatum and Avicennia marina significantly contributed to species diversity as key components in both Futian and Lujiazhuang Mangroves. Population age structure analysis revealed stable patterns in Futian and Xiwan Mangroves, whereas Luzui Mangrove showed a younger population with overall growth potential. In species diversity assessment, Luzui Mangrove demonstrated higher diversity indices with more prominent dominant species and more even species distribution. For mangrove restoration and reconstruction, we recommended adopting an integrated approach combining native and introduced species to enhance ecological stability and landscape value. Native species including Excoecaria agallocha, Avicennia marina, and Bruguiera gymnorrhiza were particularly recommended as they pose no ecological invasion risks while effectively increasing biodiversity. These species represented excellent candidates for transforming Kandelia obovate dominated communities or establishing mixed mangrove forests in Shenzhen, contributing to both ecological resilience and aesthetic value of the mangrove ecosystems. The findings provide valuable insights for developing science-based conservation strategies, highlighting the importance of maintaining species diversity and appropriate species composition in urban mangrove management. The spatial variation observed across different locations underscores the need for site-specific management approaches that consider local ecological conditions and community characteristics. This study establishes a fundamental framework for ongoing monitoring and adaptive management of Shenzhen’s valuable mangrove resources.

Dietary ecology is fundamental to understanding wildlife-habitat interactions, serving as a cornerstone for assessing environmental carrying capacity, habitat quality, habitat selection behavior, trophic structure, and interspecific competition/mutualism in community ecology. It remains a pivotal focus in endangered species conservation and biodiversity management. Ornithologists have long recognized the significance of dietary studies; for waterbirds-key indicator taxa in wetland ecosystems-dietary data elucidate species-environment energy/material linkages and critically inform ex situ conservation strategies and captive breeding optimization, particularly for threatened species. Methodologically, waterbird dietary research employs diverse approaches. Traditional techniques (direct observation, gizzard/crop content analysis, fecal microscopy) historically dominated the field. Technological advances now highlight DNA metabarcoding for its high taxonomic resolution, though constrained by sample DNA degradation and cost-intensive procedures. Conversely, stable isotope analysis demonstrates broader utility: beyond resolving dietary composition, it enables migration tracking, quantification of seasonal dietary dynamics, trophic-level mapping, and evidence-based population management and wetland restoration. Amid accelerating climate change and pervasive habitat loss/fragmentation, the scope of waterbird dietary research now transcends conventional boundaries. Objectives have expanded from basic diet characterization to multidimensional investigations of spatiotemporal foraging patterns, habitat restoration efficacy, and migratory ecology. Methodologically, interdisciplinary integration (ecology, genetics, physiology, molecular biology) drives advances in: climate-driven dietary adaptation mechanisms, gut microbiota-diet interactions, paleo-dietary evolution from fossil evidence, migration-resource phenology alignment, precision wetland rehabilitation. High-throughput, information-rich analytical tools (e.g., DNA metabarcoding, stable isotopes) provide unprecedented resolution for quantifying dietary seasonality, migration-stage shifts, and species-distribution-environment relationships. With persistent technological advancements and scientific inquiry, waterbird dietary ecology will increasingly underpin biodiversity conservation, ecosystem governance, and global change mitigation.

Mangrove wetlands are critical ‘blue carbon’ ecosystems that harbor diverse soil microbial communities playing essential roles in biogeochemical cycling. Within these communities, microorganisms can be categorized into generalists (broad ecological niches) and specialists (narrow ecological niches). However, the differential responses of these bacterial groups to infrastructure development, specifically bridge construction, and their underlying assembly mechanisms remain largely underexplored. This knowledge gap hinders our understanding of soil bacterial community evolution under anthropogenic disturbances and the development of effective mitigation strategies. Based on high-throughput 16S rRNA gene sequencing and bioinformatics analysis, this study investigated the impacts of bridge construction by comparing soil bacterial communities in two construction disturbance zones [Sheet Pile Cofferdam (SP) and Steel Casing Pipe (SC)] with those in an adjacent Undisturbed (UD) mangrove habitat. The results demonstrated a distinct divergence in how generalists and specialists responded to disturbance. In the undisturbed ecosystem, bacterial specialists exhibited significantly higher species richness (Mean=98.5) compared to generalists (Mean=49.4). However, bridge construction imposed a significant negative impact on specialists. Compared to the UD habitat, the species richness of specialists decreased notably by 38.73% in SP and 29.14% in SC sites, whereas generalist richness remained relatively stable. Moreover, the UD habitat harbored a higher number of indicator species than the SC and SP habitats, with 62.2% of them being specialists. Furthermore, construction activities profoundly altered the community structure of specialists (p<0.05), with soil organic carbon (SOC) and pH identified as the primary environmental drivers shaping these shifts. Community assembly analysis, utilizing the Modified Stochasticity Ratio (MST), revealed contrasting ecological strategies: generalist assembly was dominated by stochastic processes, suggesting high adaptability to environmental fluctuations; conversely, specialist assembly was governed predominantly by deterministic processes (environmental filtering). Notably, although bridge construction altered community composition and diversity, it did not change the community assembly processes of these bacterial groups. This indicates that the environmental stress induced by construction (e.g., carbon loss and pH alteration) acts as a strong filter, selectively eliminating taxa with narrow niche breadths. In conclusion, the impact of bridge construction on mangrove soil bacterial specialists was significantly greater than on generalists, highlighting the vulnerability of specialists and their potential utility as bio-indicators for monitoring anthropogenic disturbance. These findings provide a scientific basis for ecological management and biodiversity conservation. Therefore, conservation efforts during infrastructure development should prioritize minimizing soil physicochemical alterations to preserve the functional stability of specialist communities. Additionally, eco-friendly construction techniques, such as Steel Casing Pipes, which showed a relatively lower ecological impact compared to Sheet Pile Cofferdams, should be promoted to reduce environmental selection pressure on soil microorganisms.

To systematically elucidate the spatio-temporal variations of nitrogen contents in both soil and water body, as well as soil nitrogen transformation rates in estuarine wetlands of eastern China, this study compiled and analyzed relevant data collected from 18 major estuarine wetlands spanning latitudes from 19°07′12″N to 41°08′46″N. The investigation focused on the concentrations of different forms of nitrogen, including total nitrogen, ammonium nitrogen, and nitrate nitrogen in both soil and aqueous environments, alongside key nitrogen transformation processes such as denitrification, nitrification, anaerobic ammonium oxidation (anammox), and dissimilatory nitrate reduction to ammonium (DNRA). The primary objective was to elucidate the spatial patterns and seasonal dynamics of these variables. The results showed that the contents of different forms of nitrogen in soils were significantly higher than those in water bodies, and showed a spatial distribution pattern of higher in the south and lower in the north (p<0.05), and the soil nitrogen content in winter was significantly higher than that in other seasons. There was no obvious spatial pattern of different forms of nitrogen in water bodies, but it had higher seasonal variation characteristics in spring and autumn (p<0.05). The soil nitrogen conversion rates did not exhibit significant spatial distribution pattern (p>0.05). Specifically, soil transformation rates were significantly higher during spring compared to other seasons. The random forest model showed that several soil properties, including total organic carbon, ammonium nitrogen, nitrate nitrogen and salinity in estuarine wetlands significantly affected the spatiotemporal distribution of nitrogen conversion rates, suggesting that carbon and nitrogen content and salinity were the main driving factors of nitrogen conversion rates in estuarine wetlands in China. However, compared with other ecosystems, the nitrogen contents of different forms in soils of estuarine wetlands were low, and the nitrogen content of different forms in water bodies were lower than those in river ecosystems. Nevertheless, the nitrogen transformation rates in estuarine wetlands exceeded those measured in farmland, forest, and grassland ecosystems in different climate zones in China. Moreover, the rates were significantly higher than the global average level of wetlands. Collectively, the above results underscore the high potential of estuarine wetlands in nitrogen removal and provide an important scientific basis for evaluating the nitrogen reduction capacity of estuary wetlands in China.

Carbon (C), nitrogen (N), and phosphorus (P) are fundamental components of soil nutrients in wetlands. Their ecological stoichiometric characteristics serve as critical indicators that reflect the soil fertility supply capacity and quality, which is of great significance to nutrient cycling in wetland ecosystems. Water and salt conditions are recognized as key environmental factors governing nutrient cycling in estuarine wetlands. However, their specific impacts on the ecological stoichiometric characteristics of soil C, N, and P remain poorly understood. In this study, the freshwater wetland of the Yellow River Estuary were selected as the research object. A simulated incubation experiment was conducted using an interactive design with three water levels (surface flooding at +10 cm, surface drainage at −10 cm, and dry-wet alternation from −10 cm to +10 cm) and four salinity gradients (blank control, 5‰, 10‰ and 15‰) to investigate the effects of water-salt conditions on the stoichiometric characteristics of C, N and P. The results showed that soil C, N, and P contents over 16-weeks incubation period under different water-salt conditions ranged from 2.67 g/kg to 9.14 g/kg, 0.43 g/kg to 0.72 g/kg, and 0.54 g/kg to 0.67 g/kg, respectively. Nutrient concentrations in the control treatment were consistently higher than those in the salinity treatments. Specifically, soil C and N contents were higher under flooding conditions, whereas the water level exhibited a relatively weaker influence on soil P content. Under different water-salt conditions, the soil C:N, C:P, and N:P ratios ranged from 5.67 to 16.85, 12.21 to 36.68, and 1.65 to 2.78, respectively. Elevated salinity exerted a suppressive effect on these ratios, compared to the control, the C:N, C:P and N:P ratios in the high-salinity treatment (15‰) decreased by 14.3%, 23.2% and 10.5%, respectively. Furthermore, these stoichiometric ratios were consistently highest in the flooding treatment and lower in the drainage and dry-wet alternation treatments. Correlation analysis indicated that soil C, N, and P contents and their ecological stoichiometric ratios were positively correlated with soil water content, pH, and plant biomass, but presented negative correlations with electrical conductivity. Salinity was identified as the dominant factor controlling the variations of soil C:N and C:P in the freshwater wetlands of the Yellow River Estuary, while the variation of N:P was more strongly influenced by hydrological conditions. These findings suggest that in the context of global climate change, the declining water levels and increasing salinity in estuarine wetlands may alter the ecological stoichiometric characteristics of soil C, N and P, thereby affecting soil nutrient cycling processes.

As an important water source for human activities and economic development, the protection of lake water quality is crucial, and the mechanisms by which different types of agricultural activities affect lake water quality is urgently needed further in-depth study. With the continuous expansion of agricultural reclamation activities, processes such as farmland fertilization, pesticide use, and changes in land cover have significantly altered the patterns of material input and energy transfer in lakes, necessitating an in-depth study of their quantitative relationship with lake water quality parameters. Although existing studies have focused on the impact of agricultural activities on lake water quality, the mechanisms by which different types of cultivation, spatial patterns, and climatic conditions affect lake optical water quality parameters are still not well understood. Lake optical water quality parameters (such as chlorophyll-a (Chl-a), total suspended particulate matter (TSM), and colored dissolved organic matter (CDOM)) not only reflect the nutrient status and biological productivity of the water body, but also serve as important inputs and validation indicators for remote sensing-based water quality models. Based on recent domestic and international research results, this paper uses a combination method of bibliometrics and case analysis to review the current research status of inversion models for lake optical water quality parameters, including inversion techniques and progress of key optical water quality parameters such as chlorophyll a, inorganic suspended solids, and colored soluble organic matter. It also systematically reviews the latest research results on the impact of agricultural reclamation on optical water quality parameters of lakes, revealing the mechanisms by which agricultural activities affect lake water quality through pathways such as nutrient input, particulate matter input, and organic matter accumulation. Furthermore, through typical lake case studies (e.g., lakes in different climate zones, land use structures, and reclamation history backgrounds), the specific impacts of heterogeneity in agricultural reclamation structures on lake optical water quality parameters is explored, providing a scientific reference for lake ecological protection and sustainable agricultural development.

To explore the trophic structure and food web structure of the fish community in the Xiaoxi'ergenqi River, an investigation of its fish resources was conducted in the summer (June) and autumn (September) of 2023. By analyzing the carbon and nitrogen stable isotope values (δ¹³C, δ¹⁵N) of various organisms, the SIBER and MixSIAR packages in R were used for relevant calculations and analysis to determine the seasonal differences in the trophic structure of the catch community, and a preliminary food web of the river was constructed. The results showed that the δ¹³C values of fish in summer ranged from (−36.53‰±0.09‰) to (−28.15‰±0.08‰), and the δ¹⁵N values ranged from (6.33‰±0.24‰) to 10.23‰. In autumn, the δ¹³C values of fish ranged from (−33.08‰±0.76‰) to (−28.75‰±0.68‰), and the δ¹⁵N values ranged from (6.43‰±0.76‰) to 10.13‰. Statistical analysis indicated no significant seasonal differences in δ¹³C and δ¹⁵N values between summer and autumn (p>0.05). There was no significant difference in δ¹³C values between carnivorous and omnivorous fish (p>0.05), but the δ¹⁵N values of carnivorous fish were significantly higher than those of omnivorous fish (p<0.05). The trophic level ranges of the fish samples collected in summer and autumn were 2.63-3.77 and 2.66-3.75, respectively, with no significant seasonal differences in the trophic positions of each fish species (p>0.05). The food chain lengths of the Xiaoxi'ergenqi River in summer and autumn were 3.77 and 3.75, respectively. For the six isotope quantitative indices, the values in summer were all higher than those in autumn, indicating that the trophic diversity of the fish community was higher in summer than in autumn, while the degree of trophic redundancy was lower in summer. The study also found that among the three carbon sources, sedimentary particulate organic matter (SOM) contributed the most to the entire food web in both summer and autumn, while the contributions of suspended particulate organic matter (POM) and phytoplankton were relatively lower. According to the food web characteristics of the Xiaoxi'ergenqi River predicted by the Bayesian mixing model, the benthic food chain dominated the entire river ecosystem in both summer and autumn.

The construction of water diversion projects and cascade dams drastically alters the hydrological regimes of rivers, inducing changes in the habitats of riparian zones and exerting varying degrees of impacts on the interspecific relationships and community stability of riparian plants. Based on the zonal distribution characteristics of plant communities along elevation and moisture gradients in the middle and lower reaches of the Hanjiang River, this study conducted field vegetation surveys by dividing sampling sites into three parallel transects: Transect 1 (near-water vegetation zones), Transect 2 (intermediate zones), and Transect 3 (farthest vegetation zones from the water). Methods including niche breadth, niche similarity ratio, chi-square (χ²) test, Pearson correlation analysis, and Spearman’s rank correlation test were employed to investigate the ecological niches and interspecific relationships of dominant riparian plants, aiming to explore the effects of water diversion and cascade dams operations on plant interspecific interactions and community succession mechanisms. The results showed that there were 44 herbaceous plant species in the study area, predominantly belonging to the Poaceae and Asteraceae families. The species with the highest importance values in Transects 1, 2, and 3 were Typha angustifolia, Phragmites australis, and P. australis, respectively. Meanwhile, the species with the largest niche breadths were Erigeron canadensis, E. canadensis, and Cynodon dactylon in the three transects. The species pairs with the highest niche similarity ratios were T. angustifolia & P. australis (Transect 1), Equisetum arvense & Imperata cylindrica (Transect 2), and Lolium perenne & I. cylindrica (Transect 3). Across all three transects, more than 70% of species pairs exhibited a niche similarity ratio below 0.2, indicating low overlap in resource utilization and relatively independent interspecific relationships among riparian plants in the middle and lower reaches of the Hanjiang River. The χ² test revealed that over 80% of species pairs showed non-significant correlations in each transect, with Transect 3 presenting the loosest interspecific network structure. Further results from Pearson and Spearman’s rank correlation tests demonstrated that negatively associated species pairs dominated in all three transects, suggesting weak interspecific linkages, relative independence among dominant species, and an unstable successional stage of the plant community. Based on these findings, we recommend selecting mutualistic plant species as pioneer species for the conservation and habitat restoration of riparian plant communities in the middle and lower reaches of the Hanjiang River. This strategy will contribute to enhancing the stability of riparian plant communities and maintaining the overall functionality of the riparian ecosystem.

Lake wetlands serve as critical carbon reservoirs and sources/sinks within the terrestrial biosphere, playing a crucial role in the global carbon cycle. China is endowed with extensive lake wetland resources, and enhancing the capability to monitor and estimate their carbon source/sink dynamics is critical for achieving the national goals of carbon peak and carbon neutrality. However, considerable uncertainties remain due to limited research on carbon flux monitoring and mechanistic understanding of carbon cycling processes in these ecosystems. To improve the understanding of carbon dioxide (CO₂) flux research in Chinese lake wetlands and enhance the accuracy of carbon source/sink assessments in terrestrial ecosystems, this review classifies inland lakes of China into five distinct regions, according to the geographical regionalization framework; they are Tibetan Plateau lakes, Eastern Plain lakes, Inner Mongolia-Xinjiang lakes, Yunnan-Guizhou Plateau lakes, and Northeast Plain and Mountain lakes. For each region, we synthesize the characteristic patterns of CO₂ fluxes and identify key drivers influencing CO₂ emissions, such as climate conditions, hydrological properties, sediment characteristics, vegetation coverage, and anthropogenic impacts. Also, we provide an overview of widely applied methodologies for monitoring and estimating CO₂ fluxes, e.g. eddy covariance systems, floating chambers, and remote sensing-based models. Furthermore, this study outlines the major challenges in current research, including spatial and temporal data gaps, methodological inconsistencies, and scaling issues from site-level measurements to regional estimates. We propose future research directions aimed at strengthening long-term monitoring networks, integrating multi-source data, developing mechanistic models, and improving carbon sequestration strategies. This synthesis is expected to offer a scientific foundation for the conservation and sustainable management of lake wetlands, as well as the enhancement of their carbon sequestration potential in the context of climate change mitigation.

The Songhua River Basin plays a pivotal role in regional water supply, biodiversity conservation, ecosystem stability, socioeconomic development, and natural disaster prevention and control. However, with the acceleration of urbanization, a series of ecological and environmental quality issues have emerged in the basin. Against this backdrop, this study examined the spatiotemporal dynamics of habitat quality and land use/land cover (LULC) in the Songhua River Basin over the past three decades, and explored their intricate relationships: aiming to provide actionable insights for ecological protection and management in the region. Using LULC data from 1990 to 2020, we employed the InVEST model, land use transfer matrix, and spatial autocorrelation model to analyze the characteristics of habitat quality and LULC changes, as well as to clarify the response relationship between these two factors. The main results were as follows: from 1990 to 2020, the overall habitat quality of the Songhua River Basin showed a downward trend. The proportion of grids with medium habitat quality increased by 25.70%, while that of grids with high and very high habitat quality decreased by 5.17%. Habitat degradation was primarily concentrated in the central urban agglomerations and the ecologically fragile western regions of the basin. Notable changes in LULC were observed over the study period: both the extent and spatial configuration of cultivated land, construction land, and water bodies changed markedly. Land use conversions that exerted positive impacts on habitat quality included the shift from cultivated land to forest land (contribution ratio: 0.466) and from unused land to grassland (contribution ratio: 0.302). In contrast, conversions with significant negative impacts were: forest land to cultivated land (contribution ratio: −1.013), grassland to cultivated land (contribution ratio: −0.852), cultivated land to construction land (contribution ratio: −0.405), and water bodies to unused land (contribution ratio: −0.461). In terms of spatial distribution, habitat quality was relatively low in the central basin, yet significantly higher in the southeastern and northern regions. The global spatial autocorrelation Moran’s I values for habitat quality ranged from 0.849 094 to 0.852 893, indicating a pronounced spatial agglomeration pattern with clustering intensity on the rise over the decades. Areas with high habitat quality were mainly distributed in the upper and lower reaches of the basin, while low-quality areas were concentrated in the middle reaches. These results offer a scientific foundation for developing integrated strategies that balance regional ecological improvement with economic growth, enhance the protection and management of inland river systems, and optimize the complex plain-grassland-forest-river ecosystem pattern within the basin.

Mentougou District, located in the southwestern part of Beijing, is traversed by the Yongding River, a critical water source for the region. The ecological revetment of the Yongding River plays a pivotal role in sustaining biodiversity, maintaining water quality, and ensuring sustainable development. This study focuses on the ecological revetment of the Yongding River’s Mentougou section through field surveys, water sampling, and benthic macroinvertebrate analysis to evaluate riverbank conditions, propose restoration strategies, and assess water quality and biodiversity. Results revealed significant structural hardening and landscape monotony along the revetment, disrupting natural hydrological processes and habitat heterogeneity. Water quality analysis showed compliance with China’s Class III surface water standards (GB 3838-2002), with spatial variations observed: ammonia nitrogen (NH₃-N) concentrations ranged from 0.048 to 1.070 mg/L, total nitrogen (TN) from 0.439 to 1.850 mg/L, total phosphorus (TP) from 0.042 to 0.221 mg/L, pH from 7.40 to 8.58, dissolved oxygen (DO) from 7.18 to 8.26 mg/L, and permanganate index (CODMn) from 1.30 to 4.07 mg/L. Benthic macroinvertebrate diversity assessments indicated moderate ecological health, with Margalef richness indices ranging from 0.88 to 2.63 and Shannon-Wiener diversity indices from 0.5 to 1.7, reflecting higher pollution-tolerant taxa dominance in disturbed areas. Based on integrated analysis of physical characteristics, water quality, and biodiversity, three restoration strategies were proposed: Revetment engineering optimization through bioengineered solutions like vegetated gabion baskets and slopes to enhance habitat complexity while reducing erosion; Establishment of 30-50 m-wide riparian buffer zones using native vegetation such as willows (Salix spp.) and reeds (Phragmites australis) to filter pollutants and stabilize banks; Deployment of small-scale permeable spur dikes to promote sediment deposition and microhabitat creation. These approaches aim to reconcile flood control requirements with ecological restoration objectives, providing actionable solutions for urban river management. The study identified concrete hardening as a primary stressor, with over 65% of surveyed banks showing artificial modifications that reduced natural sediment transport capacity and riparian connectivity. Seasonal water quality fluctuations correlated with adjacent land use patterns, where agricultural zones exhibited elevated TN and TP levels during fertilizer application periods. Benthic communities displayed reduced diversity in hardened reaches, dominated by tolerant species like midge larvae (Chironomidae), while sensitive taxa were largely confined to remaining natural banks. Proposed bioengineered revetments demonstrated 40%-60% erosion reduction in pilot tests while supporting native plant colonization. Buffer zones combining woody shrubs and grasses are projected to mitigate nutrient runoff by 35%-50%, based on neighboring catchment models. Permeable spur dikes installed at 150-200 m intervals enhanced sediment retention and benthic habitat heterogeneity within six months of deployment. This framework emphasizes cost-effective integration of ecological principles with engineering needs, maintaining 100 a flood protection standards while restoring habitat complexity. Implementation costs are estimated at 60%-75% of conventional hard engineering approaches, with long-term ecological benefits including improved water quality and biodiversity recovery. The findings underscore the urgency of adopting nature-based solutions in urban watersheds, particularly in water-scarce regions like northern China. By addressing both structural degradation and ecological functionality, this strategy offers a replicable model for balancing urban development and environmental sustainability along regulated river systems.