In Heilongjiang Mulan Songhuajiang national wetland park, the seed plants were investigated in field using the sample line method and quadrat method from May to September 2017, July to August 2018, and June to October 2023, to reveal the composition characteristics of seed plants and analysis the species floristics. The results showed that a total of 53 families, 155 genera, and 217 species (including 2 subspecies and 6 varieties) of seed plants were occurred in the wetland park. The dominant families included Asteraceae (18 genera and 37 species), Poaceae (21 genera and 24 species), and Polygonaceae (4 genera and 17 species). The dominant genera included Persicaria (9 species), Carex (7 species), Artemisia and Potentilla (both 5 species). The vegetation type of the wetland park was composed of deciduous broad-leaved forests, deciduous broad-leaved shrub, meadow, herbaceous marsh, and aquatic vegetation. The main formations included Form. Salix sungkianica, Form. Carex schmidtii, and Form. Potamogeton distinctus, etc. At the species level, the flora exhibited a typical temperate distribution type, along with some tropical and subfrigid-frigid types, and had a low degree of endemism.

The 33 national wetland parks on both sides of the Shandong section of the Yellow River are important components of wetland ecosystem in the lower reaches of the Yellow River. And their ecosystem service function can affect regional ecological security and development quality. Based on the planning of national wetland parks, relevant statistical data, and field investigations, combined with the distribution characteristics, composition structure, and ecological functions of ecosystems, the equivalent factor method, correlation analysis, and spatial analysis methods were used to evaluate the ecosystem service value, and analysis the spatial changes of these parks. The results showed that the total area of 33 national wetland parks was 32 447.68 hm², with a total wetland area of 25 465.72 hm² and an average wetland rate of 76.05%. The total value of ecosystem services of 33 national wetland parks ranged from 17 million yuan to 269 million yuan, with Shandong Fulong Lake National Wetland Park in Shan County having the highest value and Yuema River National Wetland Park in Laoling having the lowest value. The ecosystem service value per unit area of the Yellow River Ancient Path National Wetland Park in Cao County was the highest. The proportion of wetland ecosystem service value in the total service value of national wetland parks was between 73.92% and 99.65%. The ecosystem service value of the national wetland Park decreased slightly downstream the Yellow River, and was higher in the southeast and lower in the northwest. The ecosystem service value is closely linked to the area and wetland rate of national wetland parks.

Based on historical land use data of the past 40 years (1980-2020) interpreted from remote sensing data in combination with relevant socio-economic data and policy collections, we analyzed the spatial and temporal dynamics of coastal wetlands and associated driving factors in the three major coastal urban agglomerations (i.e., the Pearl River Delta, the Yangtze River Delta, and the Bohai Sea Rim).zed. We calculated the degree of correlation between coastal urban wetland area and associated social and economic indicators by grey relation analysis, and also selected three typical case areas (i.e., the west coast of Shenzhen, the Pudong New District of Shanghai, and the Binhai New District of Tianjin) to conduct qualitative comparative analyses on the driving factors of coastal wetland change. The study results showed that the temporal sequence of coastal wetland dynamics of the three urban agglomerations was consistent with the temporal sequence of economic development over the past forty years, and their changes showed the temporal sequence from south to north of China. The driving factors of wetland dynamics in the three coastal urban agglomerations showed both similarity and regional differentiation. For the three typical case study areas within the three urban agglomerations, the main driving factors were population agglomeration, rapid economic growth and major infrastructure construction. The natural wetlands on the west coast of Shenzhen had experienced a rapid loss of area due to polder farming and urban construction in the early urbanisation period, and a slowing of the loss of natural wetland area in recent years due to the implementation of coastal development control and ecological restoration projects. The introduction of Spartina alterniflora and urban development projects led to the destruction of natural wetlands in the Shanghai Pudong New District. The reduction in the extent of natural wetlands in the Tianjin Binhai New District was predominantly attributable to the expansion of oilfield and salt field operations, as well as aquaculture activities.

Due to the unique geographical conditions characterized by karst landforms with numerous lakes, reservoirs, and crisscrossing rivers, Guizhou province possesses exceptional wetland ecosystems and high biodiversity. From March 2021 to January 2022, comprehensive surveys were conducted to assess species diversity across 42 important wetlands in Guizhou, focusing on phytoplankton, birds, fishes, aquatic macrophytes, and aquatic invasive species. The results revealed that a total of 188 species of phytoplankton from 8 phyla were recorded, with cell densities ranging from 3.50×10³ to 3.34×10⁸ cells/L across these wetlands. A total of 213 species of birds belonging to 55 families and 18 orders were recorded, including 27 nationally protected species. A total of 113 fish species belonging to 19 families and 6 orders were identified, with 4 species being nationally protected. In 5 representative wetlands, 249 species of aquatic macrophytes belonging to 69 families and 149 genera were reported, including 3 nationally protected species. Additionally, 6 species of aquatic invasive animals and 3 species of aquatic invasive plants were recorded, among which Alternanthera philoxeroides, Procambarus clarkii and Pomacea canaliculata exhibited rapid invasion and expansion tendencies. The species diversity of birds, fish, and large aquatic plants in 42 important wetlands in Guizhou Province is relatively high, while the cell density of phytoplankton and the risk of aquatic invasive species invasion was high in some wetlands. Therefore, it is necessary to strengthen the pollution control of lake and reservoir-type wetlands, the prevention of aquatic invasive species, and the protection of wildlife habitats.

In order to explore the community composition, temporal and spatial distribution patterns of avian diversity, and the priority conservation areas for waterfowls in urban wetlands of Zhengzhou City, as well as the impact of environmental factors on avian diversity, distribution data of bird species from 11 urban wetlands in Zhengzhou City were collected from the China Bird Watching Record Center. The similarities and differences of avian communities in different wetlands were analyzed by systematic clustering method, and the key habitat factors affecting avian diversity and priority index were explored by multiple stepwise regression analysis method. The results of the study indicated that a total of 250 species of birds belonging to 53 families and 17 orders were recorded in the 11 wetland wetlands, with Passeriformes being themost abundant. The total population of bird communities was 125 482 individuals. The dominant species of bird community include the Eurasian Tree Sparrow (Passer montanus), the Chinese Bulbul (Pycnonotus sinensis), Azure-winged Magpie (Cyanopica cyanus), Little Grebe (Tachybaptus ruficollis), Eurasian Magpie (Pica pica), Eurasian Coot (Fulica atra), Common Moorhen (Gallinula chloropus) and Mallard (Anas platyrhynchos). The inter-species correlation analysis of dominant bird species showed highly significant positive correlations between Light-vented Bulbul, Eurasian Tree Sparrow, and Azure-winged Magpie, as well as between Little Grebe, Eurasian Coot, and Mallard. Cluster analysis divided the parks into three areas, with the species richness and diversity index of the Xiliu Lake area and the central area being generally lower in spring and autumn and higher in summer and winter, while the Xiang Lake area showed the opposite trend Priority index analysis revealed that three wetlands were high-priority conservation sites for aquatic birds, three were medium-priority sites, and five were low-priority sites. Multiple stepwise regression analysis showed that as isolation, the number of habitat types, and the number of sample points increased, the species richness of birds also increased, while the building index had the opposite effect. It was recommended that more effective protection measures be taken for medium and high-priority conservation sites. In the planning and construction of wetlands, the wetlands should have a large area and a rich variety of habitat types, and the distance between different wetlands should be relatively far. At the same time, public recreation and bird habitats should be taken into account, and activities that cause significant environmental disturbances should be avoided during the breeding and nesting period.

In order to understand the structural characteristics of fish community in the Cibi Lake in Eryuan County, and provide scientific basis for formulating fishery resources protection plans, a total of four surveys were conducted to analyze the fish community structure in the Cibi Lake in March, June, September and December 2022. The results showed that a total of 5 701 fish samples weighing 61 557.8 g were collected, and 15 species were identified, belonging to 4 orders, 7 families and 13 genera. Among them, the Carp family had the largest number of fish species, with 8 species, accounting for 53.33% of the total number of species. The composition of fish species was dominated by lake settlement species, Carassius auratus, Ctenogobius giuriuns, Hemiculter leucisculus, Acheilognathus chankaensis, and Cyprinus carpio were the dominant species in the Cibi Lake throughout the year, accounting for 80.60% of the total number. The Margalef’s richness index ranged from 0.83 to 1.58, the Shannon-Wiener’s diversity index based on the number of individuals and Pielou’s evenness index ranged from 0.79 to 1.53 and 0.47 to 0.77, respectively, and the Shannon-Wiener’s diversity index based on the biomass and Pielou’s evenness index ranged from 0.78 to 1.41 and 0.45 to 0.79, respectively. The Margalef’s richness index, Shannon-Wiener’s diversity index based on the number of individuals and Pielou’s evenness index were significantly different between seasons (p<0.05), while the Shannon-Wiener’s diversity index based on the biomass and Pielou’s evenness index values were not significant between seasons (p>0.05). The stability of fish communities was highest in autumn, followed by summer, and the lowest in spring and winter.

Mudflats vegetation is important spawning medium and place for fish, which is closely related to the bait for Yangtze finless porpoise. Investigating the distribution of plant resources in the mudflat wetlands were important foundation and prerequisite for evaluating and managing the habitat status of the Yangtze finless porpoise. In the Anqing section of the Yangtze River mudflat wetland, the wild vascular plants were investigated using the combination of sample lines and sample plots surveys method to explore the composition characteristics and flora types, from April to October, 2023. The results showed that 58 families, 164 genera and 242 species of vascular plants were recorded in the mudflat wetland. Among theme, there exist ferns plants of 6 families, 7 genera and 7 species, gymnosperms plants of 1 families, 1 genera and 1 species, Angiospermae plants of 51 families and 156 genera and 234 species. Asteraceae, Poaceae and Cyperaceae are the dominant families, containing 35 species, 32 species and 27 species respectively, and the dominant genera are not obvious. The area-types of families of mudflats wild vascular plants were divided into 4 areal types and 1 subtypes, that of genera were divided into 12 areal types and 5 subtypes. And it also shows obvious concealment and the dual nature of tropical and temperate zone. In general, the mudflats wetlands in the Anqing section of the Yangtze River have a high level of vascular plant species diversity, and the natural area with large plant cover. Higher vegetation coverage not only to improve water quality of the Yangtze River, but also provides a suitable breeding and spawning ground for many fish, which own positive significance to maintain the food resources and habitat for the Yangtze finless porpoise.

Wetlands are one of the most important ecosystems on the Earth. Establishing a value accounting system for wetland resources and conducting wetland resources assessment are important links of wetland natural resources management. Based on the characteristics and management requirements of wetland natural resources assets, core indicators of wetland resource asset value accounting were selected, and an indicator system and evaluation methods were constructed. Moreover, taking the Erguna National Wetland Park as a study case, the value of wetland resource assets was evaluated. Three categories of functions were identified: supply services, regulation services, and cultural services, encompassing 14 primary indicators including food production, raw material production, water supply, flood regulation, groundwater replenishment, soil retention, wave reduction and shore protection, water purification, carbon fixing and oxygen release, climate regulation, air purification, species conservation, recreation and therapy, and science popularization education, with the further determination of 20 secondary indicators were established. The results show that the total value of wetland natural resource assets in Erguna in 2022 was 9.561 0 billion yuan, with an average value per unit area of 0. 934 8 million yuan/hm². Among the three services, the regulation service value (9 551.608 9 million yuan) was the highest, followed by the culture service value (5.306 4 million yuan), and the supply service value (4.482 5 million yuan) was the lowest. Within the total value of regulation services, the value of climate regulation function was the largest (7 267.425 6 million yuan), mainly derived from the humidity increasing function (6 599.863 5 million yuan). The Erguna Wetland plays a significant role in regional climate regulation and biodiversity conservation. This study lays the foundation for establishing a wetland resource asset accounting and evaluation system, preparing a natural resource balance sheet, and conducting ownership agency. Within the total value of culture services, the value of recreation therapy service (4.681 3 million yuan) was greater than the value of environmental education function (0.625 1 million yuan). Ecological water use (3.948 6 million yuan) was the most valuable function in supply services. The Erguna Wetland plays a significant role in regional climate regulation and biodiversity protection. This study lays the foundation for establishing a wetland resource asset accounting evaluation system, compiling natural resource asset liability tables, and conducting ownership entrusted agency.

The water level fluctuation zone is a distinctive seasonal wetland ecosystem between terrestrial and aquatic ecosystems. It serves crucial functions such as sediment trapping and the absorption of non-point source pollutants. To reveal the current status of vegetation at the water level fluctuation zone of the Heilongtan Reservoir, the plant communities' types and their distribution patterns were quantitatively evaluated using field belt surveys coupled with the Two-way indicator species analysis (TWINSPAN) classification method in June 2023. The results showed that the seed plants in the water level fluctuation zone of the Heilongtan Reservoir were comprised of 32 species within 16 families and 29 genera, with a predominance of annual herbaceous plants. The flora mainly consisted of tropical flora and northern temperate flora. As water levels ascend, there was a noted increase in the species importance value of the perennial herbaceous plants in the water level fluctuation zone, in contrast to the annual herbaceous plants, which exhibit a decline in importance with rising waters. The water level fluctuation zone of the Heilongtan Reservoir hosted a diversity of plant communities, with 10 distinct types identified, among which the Cynodon dactylon, Abutilon theophrasti, Alternanthera philoxeroides, and the Juncus alatus-Echinochloa caudata communities were notably dominant. The plant community composition within the water level fluctuation zone was significantly influenced by the depth, duration, and frequency of water inundation, with pronounced variations observed across different water level elevations. Dominant species and community structures within the water level fluctuation zone demonstrated perceptible shifts in response to the water level fluctuations, underscoring the intricate interplay between aquatic and terrestrial dynamics in this ecologically sensitive area.

The mid-to-high latitude regions are sensitive to global climate change. In recent decades, the annual average temperature increase in these regions has been much higher than the global average temperature increase. Northeast China, located in the mid-to-high latitudes, is one of the concentrated distribution areas of wetland in China. The carbon and nitrogen cycling processes in these wetlands are extremely sensitive to climate change. Focusing on the wetlands in northeast China, we summarized and analyzed the impacts and mechanisms of temperature rise on greenhouse gas fluxes. We also reviewed the changes in the source and sink functions of greenhouse gases, and identified the current research gaps, and provided prospects for future research. Overall, temperature rise can lead to increased soil temperature, accelerated plant growth, enhanced microbial activity, and changes in soil physical and chemical properties, thereby affecting the absorption or emission of greenhouse gases in these wetlands. Additionally, temperature rise may cause the wetlands in northeast China to transition from a weak source to a strong source of CH₄ and from a sink to a source of CO₂, though there remains considerable uncertainty regarding changes in N₂O sources and sinks. Existing research on the wetlands of northeast China is not comprehensive enough, lacking long-term and high-frequency monitoring and studies on multi-gradient and multi-factor interactions. Future research should address these issues through comprehensive studies and analyses and further explore the mechanisms of mutual influence among different greenhouse gas flux changes.

The environment of the Nanji Wetland in the Poyang Lake is complex and the wetland types are diverse. It is of great significance to realize the dynamic monitoring and automatic extraction of wetland information for the protection of wetland ecosystem. In this study, we used the Sentinel-2 image as the data source, the DEM data and the Google Earth high-definition image as the auxiliary data, and selected the image pure pixels as the training samples and the verification samples. According to the spectral and spatial characteristics of samples, the classification and regression tree(CART) model was constructed to realize the classification of the Nanji Wetland, and to study the types transfer changes of the Nanji Wetland from 2018 to 2021. The results showed that the combination of object-oriented CART decision tree classification method could get the classification results with high accuracy. Its overall classification accuracy could reach 86.36%, with a Kappa coefficient of 0.83, while the overall accuracy of the traditional supervised classification method was only 80.07%, the Kappa coefficient was 0.76, which was an improvement of the overall accuracy of 6.29%. The wetland types in the Nanji Wetland had obvious seasonal characteristics, with the area of grassland widely distributed in spring and winter, and most of the mudflat and grassland being flooded in summer and fall. The wetland types in the Nanji Wetland were shifted and changed mainly due to the influence of the water level and the topography factors, which mainly reflect the mutual transformation between the water area, mudflat and grassland. By the influence of water level and topographic factors, the wetland types in the Nanji Wetland had been shifted mainly in the mutual transformation among water, mudflat and grassland, and the distribution of cultivated land, forest land and building land were relatively stable. Compared with the traditional classification method, the object-oriented CART decision tree classification results were better, and the wetland information extraction could be realized quickly and efficiently.

As one of the significant carbon pool within terrestrial ecosystems, changes in soil carbon in peatlands have considerable implications for the global carbon balance. Soil enzymes and iron are important substances which affect the decomposition of soil organic matter. This article focuses on the Baijianghe peatland as the research subject, with soil samples collected from the natural area, drained, and water level restoration area at depths of 0-20 cm in April 2021. Soil physical and chemical properties, different forms of iron contents, soil enzyme activity, iron contents, Fe-bound soil organic carbon, and soil organic carbon were measured. The aims of this study were to clarify the relative importance of ‘enzyme latch’ and ‘iron gate’ mechanisms in soil organic carbon cycling within peatlands and to provide a data foundation for carbon pool management during the restoration of degraded peatlands. The results showed that after two years of rewetting, soil pH increased but soil total nitrogen content decreased. Soil Fe²⁺ and pyrophosphate-extractable iron oxides (Fe_p) exhibited a trend where the restoration area surpassed the drained area. In contrast, the contents of soil Fe³⁺, oxalate-extractable iron oxides (Fe_o), and dithionite-citrate-bicarbonate-extractable iron oxides (Fe_d) demonstrated a trend of the drained area exceeding the restoration area.Soil hydrolytic activities of the 0-5 cm depth decreased but the oxidase activities increased after rewetting. However, the activities of soil enzymes in the 5-20 cm depth did not change uniformly. Changes in soil enzyme activities were mainly affected by soil total nitrogen and iron content. In general, soil organic carbon and Fe-bound soil organic carbon contents in the restoration area were higher than those in the drained area. After rewetting, soil pyrophosphate-extractable iron oxides content increased which was benefit for the increasing of Fe-bound soil organic carbon content. However, the 'iron gate' mechanism was not the main cause of soil organic carbon increasing after rewetting. Soil iron regulated soil organic carbon mainly through affecting enzyme activities. The ‘enzyme latch’ mechanism was found to play a crucial role in regulating soil organic carbon during the rewetting process of degraded peatlands in spring.

In order to scientifically and accurately study the spatial allocation of plants in wetland parks, a habitat suitability curve was established based on the requirements of wetland plants and waterfowls on water level of key habitat factors. Combined with the spatial distribution of wetland water level, a comprehensive habitat model based on the habitat requirements of wetland plants and waterfowls was constructed. The spatial distribution of Habitat suitability index (HIS) of wetland plants and waterfowls under the current control water level of 4.2 m and the restored control water level of 4.5 m in Nanjing Lvshuiwan Wetland Park was simulated. At the same time, the Weighted usable area (WUA) and the area of high-quality habitat were calculated, and the two methods considering only plant habitat and the comprehensive consideration of plant and waterfowls habitat were analyzed and compared, and the plant spatial allocation scheme was proposed. The results showed that the area of high-quality wetland plant habitat calculated by the comprehensive method was smaller than that obtained by the single method, and the variation amplitude of floating leaves and water-supporting plants was larger than that of submerged plants, and the impact of changing water level on the habitat area of floating leaves and water-supporting plants was greater than that of submerged plants. The method of plant allocation in wetland park based on the needs of plants and waterfowls provides a reference for ecological restoration of wetland park.

Dalian and Yingkou are two representative coastal cities in Liaoning, which have many types of wetlands and rich resources. In order to clarify the current situation of typical wetland ecosystems in Northeast China, the wetland area and biodiversity in Yingkou and Dalian were investigated. The results showed that the wetland area of Dalian was 42 524.94 hm², while the wetland area of Yingkou was 14 957.07 hm². The coastal tidal flats accounted for the highest proportion, 41 695.54 hm² for Dalian and 11 694.78 hm² for Yingkou, respectively; while the shrub swamp accounted for the lowest proportion, 5.62 hm² for Dalian and 1.65 hm² for Yingkou, respectively. As for the wetland biodiversity, it was found that the proportion of wetland vegetation and fish was the highest, while the proportion of amphibians was the lowest. Among them, Dalian had 81 families of 474 species of wetland vegetation, while Yingkou had 30 families of 134 species of wetland vegetation; Dalian had 108 families of 274 species of fish, while Yingkou had 58 families of 124 species of fish; Dalian had 6 families of 14 species of amphibians, while Yingkou had 4 families of 5 species of amphibians. This paper expounds the importance of wetland to the balance of ecological environment and puts forward the protection countermeasures of wetland ecosystem through the general situation, resource characteristics, protection status and existing problems.

The brooding period is the key stage of bird breeding period. The study of bird brooding period behavior is helpful to reveal the living conditions of bird in the environment and has positive significance for bird conservation. In June 2022, a comparative study on the brooding period behavior of Oriental White Stork (Ciconia boyciana) was carried out in Bainiao Lake and Xingkai Lake, Heilongjiang, China. The brooding period behavior of Oriental White Stork in Bainiao Lake and Xingkai Lake was observed and compared by instantaneous scanning and frequency ratio statistical methods. The results showed that in terms of time budget, there was a significant difference in the time budget of Oriental White Stork between Bainiao Lake and Xingkai Lake. Adults of Oriental White Stork in Bainiao Lake spent less time on foraging behavior, and spent more time on preening, vigilance and nesting behavior. Chicks of Oriental White Stork in Bainiao Lake spent less time on resting behavior, and spent more time on walking, standing and nesting. In terms of behavior diurnal rhythm, the Oriental White Stork in Bainiao Lake and Xingkai Lake had certain rhythms, however there were adaptive changes under different environmental conditions, resulting in obvious differences; the peak of adult vigilance behavior of Oriental White Stork in Bainiao Lake coincided with the peak of traffic flow, however the adult vigilance behavior of Oriental White Stork in Xingkai Lake did not show obvious daily rhythm.

Rural small wetlands perform significant ecological services, but most of these wetlands lack adequate management and protection. In order to scientifically understand and protect rural small wetlands, this study investigated the vascular plant composition of a total of 27 small wetlands in rural small lakes, reservoirs, and channels in Gong’an County, Jingzhou City, Hubei Province, as well as the anthropogenic factors such as surrounding land use, slope protection mode, human interference intensity, present function, number of water pollutant species and water nutrient degree, and viewed them as the driver factors to analyse the species richness. The results showed that a total of 115 species of vascular plants were found in 42 families and 84 genera in the small wetlands of Gong’an County. The distribution types of family and genus were mainly world distribution type and tropical distribution type. Angio-sperms were absolutely dominant, and the dominant families were Gramineae and Cyperaceae, and the life types of plants were mainly perennials. The results of non-metric multidimensional scaling showed that there were differences in the vegetation composition of the three types of small wetlands. There was no significant difference in species richness among the three types of small wetlands and the species richness was lower in autumn than that in summer. Furthermore, the drivers of species richness were ranked by importance using the shapley additive explanation model and a structural equation model was constructed. The results showed that the most important driving factor was the surrounding land use form, followed by the slope protection mode. The surrounding land use form was the most significant interaction affecting species richness, which had a direct positive effect on species richness, and had negative and positive effects on species richness through the impact of present function and slope protection mode.

Mangroves play a crucial role in carbon cycle and budget of coastal ecosystems, and it is important to identify the source and variation characteristics of mangrove soil organic carbon. In March (spring) and November (autumn) of 2016, mangrove wetland in the Jiulong River Estuary Mangrove Provincial Nature Reserve in Longhai, Fujian Province was selected as study object, soils of landward mangrove, seaward mangrove, and tidal flat in half-mature and mature forests of Kandelia obovate were collected to analyze the changes of soil organic carbon contents and storages at 0-100 cm depths, and the contributions of different potential sources of soil organic carbon were identified using the Stable Isotope Mixing Model (SIMMR). The results showed that the soil organic carbon contents in half-mature and mature forests were ranged from 9.80 to 30.10 g/kg and 9.40 to 30.97 g/kg, respectively, and their storages in autumn were 25.6% and 19.1% higher than those in spring, respectively. The δ¹³C and δ¹⁵N values in all soils ranged from -28.20‰ to -23.68‰ and 2.39‰ to 10.98‰, respectively. The δ¹³C values in seaward mangrove and tidal flat soils were higher than in landward mangrove. Maricultural particulate organic matter was the main source of soil organic carbon, with an average relative contribution of (32.6±3.7)%, followed by riverine particulate organic matter (23.3±10.2%) and C3 plants (20.1±0.9%). The contribution proportion of mariculture and C3 plants was highest in the landward mangrove, while the contribution of river was highest in the tidal flat soil. Moreover, the contribution of autochthonous sources to soil organic carbon showed seasonal differences. Soil organic carbon storage in mangrove wetland decreased from landward to seaward, and soil organic carbon mainly originates from allochthonous sources. Therefore, mangrove ecosystems have strong capacity for carbon capture and sequestration.

Zooplankton as a significant biological constituent within the wetland food web, plays a crucial role in the assessment of wetland water quality and system health. To investigate the effects of environmental factors on the community structure of metazooplankton in typical northern swamp wetlands, a study was conducted in July 2023 in the Momoge National Nature Reserve in Jilin Province. A total of 24 sampling sites were established in typical swamp wetlands (12 in shallow water zones and 12 in deep water zones). Surveys of metazooplankton and water environmental factors were conducted, and a comparative analysis was performed to explore the structural characteristics of metazooplankton communities as well as their influencing factors in both shallow water and deep water zones. The results of the study revealed that a total of 84 metazooplankton species were documented, among which rotifers constituted the dominant group with 50 species. The average abundance and biomass of metazooplankton were 18.10 ind./L and 50.46 μg/L, respectively. There were six dominant species overall, with five found in shallow waters and four in deep waters.The Pielou evenness index for metazooplankton communities was significantly higher in shallow waters than in deep waters, whereas the Shannon-Wiener diversity index and Margalef richness index showed no significant difference between the two regions. The results of non-metric multidimensional scaling analysis demonstrated that the community structure of rotifer groups exhibited large spatial variations, while the communities of copepods and cladocerans presented small differences. Water depth (WD), nitrate-nitrogen concentration (NO₃^--N), total nitrogen content (TN), and total phosphorus (TP) content have been identified as the principal environmental factors influencing the community structure of metazooplankton.

The Baiyangdian Wetland Nature Reserve is situated in Xiong'an New Area, Hebei Province. From January 2021 to December 2022, a bi-monthly survey of Odonata was conducted in seven representative areas. Through species identification and statistical analysis, the abundance and diversity indices of Odonata were examined. The findings revealed a total of 21 species from 17 genera and 6 families within the Odonata, with the Libellulidae exhibiting the highest number of species at 52.38% of the total, followed by Coenagrionidae at 23.81%, which represented an increase of four species compared to previous surveys. Ischnura elegans emerged as the most dominant species alongside four other dominant ones: Ischnura asiatica, Paracercion plagiosum, Crocothemis servilia and Rhyothemis fuliginosa. A total count of 2 724 adult Odonata was recorded during the two-year survey period while June showing the highest species abundance and richness observed while July exhibited the highest Shannon-Wiener diversity index. In compared with Shannon-Wiener diversity index H′, Pielou evenness index and interspecific random encounter rate PIE, Margalef richness index showed significant discrimination in monthly Odonata communities in Baiyangdian wetland and proved more suitable for evaluating population dynamics of Odonata in this area.

Tianjin, as a crucial wetland area in the Bohai Bay region and a sensitive zone under the dual pressures of land-sea interaction, faces significant ecological security challenges exacerbated by global climate change and human development activities, including the degradation of wetland ecosystem services, disruption of ecological network patterns, and the shrinking of safe habitats for waterbirds. This study focus on wetland waterbirds in Tianjin, adopts a “species-habitat-restoration” perspective to identify ecological source areas based on habitat suitability. By using habitat suitability evaluation results, the initial resistance surface is modified. And ecological corridors were extracted using the least-cost resistance model to construct the ecological security pattern for waterbirds in the wetlands of Tianjin City. The results indicate that the total area of waterbird ecological source in Tianjin’s wetland is 2 695.06 km², accounting for 21.05% of the city’s total area, mainly distributed in Binhai New Area, Baodi District, Jizhou District, Ninghe District and Jinghai District. A total of 120 key ecological corridors, with a spoon-shaped distribution, are mainly located along the source areas and river systems, ensuring the connectivity between the waterbirds habitats in Tianjin City. A comprehensive plan for the identified source areas and ecological corridors is proposed, including strategies for constructing ecological corridors for waterbird activities, establishing waterbird activity protection hotspots, and designating of key protected plots for waterbird activities. Macroscopically, this forms a wetland waterbird ecological security pattern of “two screens, three corridors, six areas and multiple points”. The approach of identifing source areas based on habitat suitability and modifying the basic resistance surface through habitat suitability results comprehensively considers the significance of ecological processes in the construction of the wetland waterbird ecological security pattern. This study provides a practical pathway and scientific guidance for solving the problem of wetland waterbird ecological security in Tianjin City.

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 construction of natural education is an important approach for the sustainable utilization of wetland parks and holds significant meaning for achieving harmonious coexistence between humans and wetlands. By sorting out the development context of natural education and analyzing the existing problems in natural education within China's wetland parks, a construction model for natural education in wetland parks was proposed. This study focused on the Guanwanshan National Wetland Park in Feidong, Anhui, which is the first national wetland park in China characterized by its traditional pond wetlands. By analyzing and evaluating the natural education resources of the park, construction strategies were proposed for emphasizing the value of natural education resources, thematic differentiation, local authenticity of the sites, multi-dimensional media, and systematic curriculum development. These strategies aimed to guide the direction of wetland park development and form a comprehensive development model based on natural education. The planning practices guided by natural education in the park had effectively preserved and rejuvenated the essence of pond culture and heritage in the new era.

Allelopathy of plants in wetland is of great significance for revealing the mechanism of plant species composition and distribution, community succession and biological invasion in wetland ecosystem. Based on the basic concept and variety/categories of allelopathy of plants in wetland and its means of release and action mechanisms, this paper discusses the main contents of current plants in wetland allelopathy researches from the following aspects: Allelopathic effects on species composition and community structure of plants in wetland. Allelopathic effects on the succession process of plant communities in wetland. Allelopathic effects on invasive processes of exotic plants. Application of allelopathy of plants in wetland ecological restoration. It is suggested that further optimization of research methods should be used to evaluate the allelopathic effects of plants in wetland and their results, and to study the effects of allelopathic effects on the processes of vegetation species composition and community structure succession under the changes of abiotic environmental conditions, and to strengthen the construction of natural chemical regulatory systems in the process of wetland ecological restoration.

Due to the better pollutant removal effect and smaller footprint area, the subsurface flow constructed wetland is widely used in the purification of tail water from sewage treatment plants. However, with the operation of subsurface flow constructed wetland, the clogging problem occurs, which seriously affects the pollutant removal effect of the subsurface flow constructed wetland. In this paper, the clogging mechanism, clogging monitoring and evaluation methods of subsurface flow constructed wetland were reviewed. The clogging solution of subsurface flow constructed wetland was put forward from the early design stage and the later operation & maintenance management, so as to provide some reference for solving the clogging, prolonging the service life and maintaining the stable operation of subsurface flow constructed wetland.

This study conducted a monthly investigation on the spatiotemporal characteristics of phytoplankton communities at 11 sites in the Qionghai Lake from May to November 2022. A total of 137 species of 76 genera and seven phyla were successfully identified. Green algae and diatoms dominated the composition of algae, and there were noticeable spatial and temporal differences in algae community structure. The density varied from 305.63×10⁴ to 706.91×10⁴ cells/L, averaging 442.76×10⁴ cells/L. Moreover, the density of algae in June was significantly higher than those in other months. Cyclotella sp., Chlorella sp. and Oocystis sp. were the dominant species every month. The water quality was generally good, corresponding to the Shannon-Wiene index, Simpson index, and Pielou evenness index ranging from 3.16 to 3.66, 0.82 to 0.88, and 0.66 to 0.75. The algae diversity was significantly higher from May to August than from September to October. At the same time, the comprehensive trophic level index was lower than 40, which was the medium nutrient level. In the northwest, the water quality in the Gaojian Bay was a light eutrophication level. The RDA analysis showed that the main environmental factors significantly affected the composition and distribution of alga community in the Qionghai Lake. Total phosphorus concentration had the most significant impact on phytoplankton, accounting for 31.1% (p<0.01) of the total variation rate, followed by dissolved oxygen (24.7%), water temperature (17.3%), and pH (10.6%). The Chlorophyll a concentration was negatively correlated with transparency (R=-0.65, p<0.01), while it was significantly positively correlated with permanganate index (R=0.35, p<0.01), ammonia nitrogen (R=0.43, p<0.01), total phosphorus (R=0.73, p<0.01), total nitrogen (R=0.39, p<0.01), and comprehensive trophic level index (R=0.35, p<0.01), respectively. These results indicated that the phytoplankton biomass in the Qionghai Lake increased with water nutrient concentration. In contrast, the biomass decreased with water transparency. Notably, the Shannon-Wiener index, Simpson index and Pielou evenness index were positively correlated with transparency and negatively correlated with permanganate index, ammonia nitrogen, total phosphorus, total nitrogen, and comprehensive trophic level index. On the whole, total nitrogen, ammonia nitrogen, water temperature, dissolved oxygen, permanganate index, and transparency were the main factors affecting the distribution of algal populations in the Qionghai Lake.

Eutrophic water often experience algal blooms, with Microcystis being the dominant species that triggers algal blooms. It usually exists in the form of colonies, and the formation of Microcystis colonies is the critical causes in the important stages leading to algal blooms. This purpose is to reveal the mechanism of blooms through the morphological characteristics of Microcystis colony formation and the physicochemical properties of extracellular polymeric substances (EPS). The results showed that Ca²⁺ effectively induces the formation of Microcystis colonies, which consisted of three stages: cell aggregation, colony amplification, and colony maintenance. The stages of cell aggregation and colony amplification were dominated by the cell adhesion mechanism. Individual cells rapidly aggregated to form loose Microcystis colonies within 1 day of the experiment starting. The experimental groups with Ca²⁺ mass concentrations of 100 mg/L, 500 mg/L, and 1 000 mg/L achieved the maximum median diameter of 28.12 μm, 29.40 μm, and 33.26 μm at 5 d, 3 d and 3 d, respectively. During the colony maintenance stage, large colonies broke up into smaller ones, but the algal cells preserve the colony shape by cell division mechanism, and the median diameter was stable at 18.19 μm to 20.39 μm by day 9. Extracellular polymeric substance of different components played unique function in the three stages of Microcystis colony formation. Soluble extracellular polymeric substance plays a key role in the cell aggregation stage, whereas bound extracellular polymeric substance contributes significantly to amplification and maintenance of Microcystis colony. This proposes a method for evaluating Microcystis colony morphological characteristics while also analyzing secretion patterns and physicochemical properties of extracellular polymeric substance. It emphasizes the role of soluble extracellular polymeric substance in the colony aggregation, providing a theoretical foundation for understanding the mechanism and action of Microcystis colony formation in the early stages of algal blooms.

From December 2019 to October 2020, macrobenthos samples in three habitats of Phragmites communis, Sonneratia apetala and bare flat in the Nansha Wetland of Guangzhou were collected, and the secondary productivity and P/B value (the ratio of secondary production to biomass) were calculated and analyzed to reveal the spatiotemporal characteristics of macrobenthos. The results indicated significant differences in the secondary productivity and the P/B ratio among the macrobenthic communities across different habitats. The average annual secondary production of macrobenthos in the P. communis weland, the S. apetala wetland and the bare flat were 36.59 g/(m²·a), 13.31 g/(m²·a) and 4.56 g/(m²·a), respectively, and the P/B values were 1.24, 1.20 and 0.84, respectively. The secondary production of macrobenthos in the P. communis wetland was the highest, followed by that in the S. apetala wetland, and the lowest in the bare flat. A two-way analysis of variance indicated that the secondary production and P/B ratios of macrobenthos differed significantly among the three habitats (F=6.50, p<0.01), but no significant differences were observed among different seasons (p>0.05). Correlation analysis indicated that the secondary production of macrobenthos was significantly negatively correlated with soil pH (p<0.05), and the P/B ratio was significantly negatively correlated with soil salinity and electrical conductivity (p<0.05).

In order to know the status of wetland plants and strengthen their protection and management in Wenchang city, Hainan, a field investigation of wetland plants in Wenchang was conducted from March to May in 2023, using a combination of line transect method and quadrat method, and the floristic composition and characteristic of vascular plants in the area were analyzed. The results showed that a total of 245 species from 73 families and 188 genera had been recorded in the wetland of Wenchang, including 9 fern species from 5 families and 6 genera, and 236 angiosperm species from 68 families and 182 genera, with the dominant families Euphorbiaceae, Fabaceae, Syzygiaceae, Chrysanthemums, Verbenaceae, and Gramineae. Plant habits were predominantly herbaceous, and ecological types are primarily hydrophytes. Two wild plant species, Xylocarpus granatum and Nypa fruticans, were under national second-class protection, while 23 wild plant species (belonging to 13 families, 17 genera) under provincial protection. Wetland plants in Wenchang could be divided into 6 areal-types and 5 subtypes at family level, while 11 areal-types and 5 subtypes at genus level. The tropical distribution families and genera accounted for 91.07% and 94.80% of non-cosmopolitan families and genera, respectively, which indicating that the wetland flora of Wenchang had obviously tropical nature. In general, Wenchang possessed abundant species of wetland plants.

The Jiangsu Yancheng Wetland National Nature Reserve for Rare Birds serves as an essential stopover and wintering ground for migratory birds along the East Asia-Australasian Flyway. During the wintering season from November 2022 to February 2023, a survey of waterbirds was conducted in the restoration area of the reserve's experimental zone. Basic data including waterbird number and community composition, as well as their habitat utilization, were collected. The results indicated that, during the wintering period, a total of 36 waterbird species (23 019 individuals) belonging to 7 orders and 12 families were recorded, with 4 national first-class and 3 second-class protected species in China. The globally endangered (EN) species Oriental White Stork (Ciconia boyciana), 3 globally vulnerable (VU) species, and 2 globally near threatened (NT) species listed in the IUCN Red List of Endangered Species lists were observed. Gadwall (Mareca strepera), Mallard (Anas platyrhyncho), Chinese Spot-billed Duck (Anas zonorhyncha), and Common Coot (Fulica atra) were the dominant species in the restoration area. Habitats of waterbirds included bare land, shallow water area, deep water area, post-harvested reed marsh, post-harvested calamus marsh, and pond ridges. Significant differences in waterbird numbers and compositions were identified across habitats. A total of 19 species (18 372 individuals) were recorded in deep water area, which was the highest among habitats. The community of deep water area was distinct from those of bare land, post-harvested reed marsh, post-harvested calamus marsh, and pond ridges. The shallow water area exhibited the highest Shannon-Wiener diversity index. Regular waterbird monitoring is crucial to enhance our understanding of habitat utilization by waterbirds and the status of restored wetlands. Maintaining the diversity of habitats based on the ecological needs of waterbirds is vital for wetland management and waterbird conservation.

It is of great significance to explore the characteristics of plankton community structure in the tidal channels of the Yellow River Delta for assessing the ecosystem health of the tidal flat wetlands. In April 2021, two tidal channel networks affected by different human activities in the Yellow River Delta were selected to carry out the field survey of plankton, and the distribution characteristics and influencing factors of phytoplankton and zooplankton were analyzed. The results showed that there were 45 species of phytoplankton in the tidal channel network of the Yellow River Delta, belonging to 3 phyla and 36 genera, among which the diatoms and dinoflagellates were predominant. There were 22 species of zooplankton, mainly belong to copepods and larva. The diversity analysis showed that the diversity, evenness and abundance of phytoplankton and zooplankton were at a high level. The synchronization analysis showed that the zooplankton in the tidal channel network had higher synchronization than phytoplankton. The correlation analysis showed that plankton community diversity was not significantly correlated with water environmental factors, but the community biodensity was positively correlated with electrical resistivity and redox potential, and negatively correlated with salinity, specific conductance and total dissolved solids.

The quantitative assessment of wetland water purification functions is important for wetland restoration and water environment management. Based on the literature review, the purification mechanisms of wetlands for suspended solids, organic matter and nutrients have been summarized. The types, advantages and disadvantages, and limiting factors of constructed wetlands were analyzed. The functions of constructed wetlands in purifying new pollutants and reducing greenhouse gas emissions need to be further enhanced. In addition, the quantitative assessment methods for the water purification function of natural wetlands have been summarized, and the driving factors and limiting factors of the hydrological, hydrodynamic and vegetation modules in the numerical simulation have been sorted out. Additionally, a notable contribution of this review is its focus on the advantages of assessing water purification functions from the perspective of wetland complexes within a watershed. This approach provides valuable insights for establishing appropriate pollutant concentration control thresholds, which are particularly relevant in the context of wetland ecological restoration projects, comprehensive water quality improvement efforts across entire watersheds, and the planning and implementation of water transfer projects for lake wetlands. Finally, the review proposes future research directions based on an analysis of current research trends and identified gaps in the field of wetland water purification studies. It suggests a strategic shift in focus from single wetland research to a broader watershed scale perspective that considers wetland complexes. The review also advocates for increasing the density of data monitoring in key water quality areas, establishing long-term and large-scale ecological databases, and developing integrated models of large-scale wetland complexes. These initiatives are conducive to enhancing the ecological construction level of the entire river watershed in China and the water purification capacity of wetlands.

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.

In order to know the status of wetland plants and strengthen their protection and management in Wenchang city, Hainan, a field investigation of wetland plants in Wenchang was conducted from March to May in 2023, using a combination of line transect method and quadrat method, and the floristic composition and characteristic of vascular plants in the area were analyzed. The results showed that a total of 245 species from 73 families and 188 genera had been recorded in the wetland of Wenchang, including 9 fern species from 5 families and 6 genera, and 236 angiosperm species from 68 families and 182 genera, with the dominant families Euphorbiaceae, Fabaceae, Syzygiaceae, Chrysanthemums, Verbenaceae, and Gramineae. Plant habits were predominantly herbaceous, and ecological types are primarily hydrophytes. Two wild plant species, Xylocarpus granatum and Nypa fruticans, were under national second-class protection, while 23 wild plant species (belonging to 13 families, 17 genera) under provincial protection. Wetland plants in Wenchang could be divided into 6 areal-types and 5 subtypes at family level, while 11 areal-types and 5 subtypes at genus level. The tropical distribution families and genera accounted for 91.07% and 94.80% of non-cosmopolitan families and genera, respectively, which indicating that the wetland flora of Wenchang had obviously tropical nature. In general, Wenchang possessed abundant species of wetland plants.

Ecological sensitivity assessment plays a crucial role in regional environmental protection and the formulation of functional zoning. Using GIS, an ecological sensitivity assessment was conducted on the Longfeng Wetland. Eight indicators elevation, slope, slope aspect, vegetation cover, water body buffer zone, land use type, road buffer zone, and settlement were selected to construct an ecological sensitivity evaluation system. The Analytic Hierarchy Process (AHP) and GIS spatial analysis were employed to assess the ecological sensitivity of the study area. The results indicate that the overall ecological sensitivity of the Longfeng Wetland is relatively low, with a predominance of moderately sensitive areas; vegetation cover and water body buffer zones have the greatest influence on ecological sensitivity; non-sensitive, moderately sensitive, and highly sensitive areas account for 39.5%, 46.4%, and 14.1% of the Longfeng Wetland's total area, respectively; highly sensitive areas are concentrated in the northeastern and central parts of the study area, primarily in reed marsh wetlands, with additional concentrations in the southwestern part's bog wetlands. Moderately sensitive areas are distributed around the periphery of highly sensitive areas, while the remaining areas are non-sensitive, primarily located along the edges of the study area. The basic spatial pattern of sensitivity is a gradual decrease from the central water body of the protected area outward. Based on the evaluation results, relevant recommendations for environmental protection and ecological construction are proposed to provide reference for the protection of wetland ecology and the planning of wetland landscapes.

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 order to investigate the seasonal changes and key driving factors of phytoplankton community structure and functional groups in the Songhua Lake, the phytoplankton and water environmental factors at 12 sampling points were investigated in summer and autumn of 2020, and spring and summer of 2021. Functional group classification, comprehensive nutrition state index, cluster analysis, non-metric multidimensional scaling analysis (NMDS) and redundancy analysis (RDA) were employed to analyze the succession characteristics of phytoplankton community structure. The results showed that species of phytoplankton were identified in the Songhua Lake from 2020 to 2021, 108 species of phytoplankton belonging to 8 phyla were detected, among which Chlorophyta accounted for the highest proportion (41.67%), followed by Bacillariophyta (26.85%). Thirteen dominant species were found during the investigation, and Aphanizomenon sp. was the only common dominant species in the four investigations. Phytoplankton in the Songhua Lake were classified into 23 functional groups, with 5 dominant functional groups including P, Lo, Y, MP and D, which shared the common feature of adaptation to medium to high eutrophic water. In terms of time series, changes of dominant functional groups from 2020 to 2021 were P/M/Y/D/B/H1-Y/B/D/X2/P-MP/Y/Lo/P/D-Lo/P/H1/Y/MP, P and Y were the common dominant functional groups in each region of reserve. The results of RDA analysis showed that the eigenvalues of the first and second ordination axes were 17.34% and 11.90%, respectively. Water temperature, pH and total nitrogen were the main factors driving the distribution pattern of phytoplankton functional groups. The results of this study provided data for the management of aquatic ecology in the Songhua Lake.

The wetland requisition-compensation balance policy, an important ecological conservation strategy in China, mandates equivalent-area compensation for development-occupied wetlands to maintain regional wetland inventory. However, widespread functional heterogeneity exists among wetland types. Since China formally institutionalized the concept of ecological products in 2006, scholarly focus has shifted toward quantifying wetland ecological product values encompassing provisioning services, regulating services, and cultural services to comprehensively reflect intrinsic wetland functions. In order to investigate the effects of current wetland requisition-compensation balance policy on ecological profit and loss of regional wetland functions, this study calculated and evaluated the values of wetland ecological product in Yancheng in 2022 based on gross ecosystem product (GEP) accounting model. The results demonstrated that the wetland in Yancheng was classified into 5 types, including coastal wetland, marshy wetland, riverine wetland, lacustrine wetland, and human-made wetland, of which the total area was 5 678.36 km². The total value of wetland ecological product in Yancheng reached 140.094 billion yuan, comprising provisioning services (26.632 billion yuan), regulating services (107.576 billion yuan), cultural services (5.886 billion yuan). The mean value of unit-area wetland ecological products averaged 22.30 yuan/(m²·a). In terms of different types of wetland, their values from high to low were: coastal wetland [32.65 yuan/(m²·a)], lacustrine wetland [24.57 yuan/(m²·a)], riverine wetland [19.97 yuan/(m²·a)], human-made wetland [19.22 yuan/(m²·a)], and marshy wetland [15.08 yuan/(m²·a). Different wetland types exhibit divergent functional orientations and ecological function values. Coastal wetland provided unique coastal protection [3.66 yuan/(m²·a)]. As to different types of wetland ecological function, value for flood regulation was highest [14.13 yuan/(m²·a)], while value for carbon sequestration was lowest [0.01 yuan/(m²·a)]. Functional equivalence analysis reveals that uniform ecological value can be achieved when the area ratios of coastal wetland: lacustrine wetland: riverine wetland: human-made wetland reach 1.00:1.33:1.63:1.70:2.17. Consequently, it is suggested that when implementing the requisition-compensation balance mechanism across different wetland types, the equivalent value conversion from requisitioned area to ecological compensation can be calculated based on the unit-area wetland ecological product value. This approach can ensure zero net loss of regional ecological product value.

In order to research the environmental carcinogenic risks and sources of ²³⁸U and ²³²Th in the water of the Haihe River, Concentrations of ²³⁸U and ²³²Th were measured by ICP-MS. The pollution levels and carcinogenic risks of ²³⁸U and ²³²Th in the water of the Haihe River were evaluated based on a Monte Carlo simulation combined with the Nemerow Index and Carcinogenic Risk models. The source apportionment was fulfilled by Spearman’s rank correlation coefficient method and the Positive Matrix Factorization model (PMF 5.0). The results showed that the activity concentrations of ²³⁸U and ²³²Th were (36.5±25.2) mBq/L and (0.041±0.037) mBq/L in the water of the Haihe River, respectively. Activity concentrations of ²³⁸U were much higher than ²³²Th. ²³⁸U activity concentrations were highest in January, followed by April and October, with a minimum in July. The concentrations of ²³⁸U and ²³²Th in the middle and lower reaches were higher than those in the feeding rivers and upper reaches. The probabilities of pollution of ²³⁸U and ²³²Th were less than 20% in April, July, and October. However, there was a high risk of pollution in January. The probabilities of pollution in the feeding river and the upper reaches were extremely low. The risk of pollution occurring in the both middle and lower reaches ranged from 11% to 14%. The carcinogenic risk index in the Haihe River is between

10^-4 and 10^-6, suggesting that there was a potential risk of cancer. The order of total carcinogenic risks was Children, Adults and Teenagers. The results of source apportionment showed that there were four pollution sources for ²³⁸U, namely, agricultural, industrial, cosmic rays, and soil. Their contributions were 61.4%, 12.6%, 8.9% and 17.1%, respectively. There were three pollution sources for ²³²Th, that was, industrial, cosmic rays, and soil, with contributions of 18.1%, 59.8%, and 22.1%, respectively. The scientific based for the prevention of uranium and thorium pollution in the Haihe River are provided from this work.

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.

Tidal creeks, as unique components of coastal landform, have gradually attracted attention for their abilities of hydrological connectivity, material transportation and biodiversity. They can maintain the salt-and-water balance of tidal flats, transport sediments between ocean and land, be a spreading channel for plant seeds of coastal wetland, and provide habitats for marine organisms, which benefit the stability of coastal ecosystems. After extreme climate events and human activities, unchangeable shape and increasing biodiversity of tidal creeks is a signal of the restoration of coastal ecosystem. Therefore, it is of great significance to explore their morphological changes and ecological impact. Based on several researches of dynamic changes and ecological effects of tidal creeks in recent years, this paper reviews the classification methods, morphological characteristics, influencing factors and ecological effects of them, and puts forward three directions that need to be followed in the future: Spatial distribution and morphological characteristics of tidal creeks in different coastal wetlands with different influencing factors; Simulation and prediction of coastal seed transportation in tidal creeks. The relationships between the morphology, hydrological connectivity and ecological effect of tidal creeks.