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 understand the flora composition and distribution types of vascular flora in the Zhongshan River National Wetland Park, Wuping, Fujian Province, and the differences of flora with other eight wetlands, the flora richness of different regions was studied by Zuojiabu comprehensive coefficient method, and the correlation of the flora geographical components was compared by principal component analysis and cluster analysis. The results showed that there were 795 species of wild vascular plants belonging to 493 genera and 169 families in the Zhongshan River National Wetland Park, including 84 species of ferns belonging to 57 genera and 35 families, 7 species of gymnosperms belonging to 7 genera and 6 families, and 704 species of angiosperms belonging to 429 genera and 128 families. There were 151 families, 272 genera and 397 species of monospeciae and oligospeciae families, accounting for 89.35%, 55.17% and 49.94% of the total number of families, genera and species, respectively. There were 485 genera and 736 species of monospeciae and oligospeciae genera, accounting for 98.38% and 92.58% of the total genera and species, respectively. There were 14 families, 24 genera and 25 species of alien invasive plants, mainly herbaceous plants. There were 1 species of national first-class key protected plant and 10 species of national second-class key protected plants. The geographical composition of wetland plants was complex and diverse, with obvious tropical attributes in the distribution types of families and genera, showing the characteristics of transition from mid-subtropical to southern subtropical. There were 75 tropical families and 29 temperate families, accounting for 72.12% and 27.88%, respectively, of which pan-tropical distribution family and northern temperate distribution family was dominant. There were 281 tropical genera and 138 temperate genera, accounting for 65.96% and 32.39%, respectively. The geographical composition analysis of plant genera showed that it was most closely related to the Lipu Lijiang Wetland and the Ruyuan Nanshuihu Wetland, and most distantly related to the Haining Changshuitang Wetland. Compared with the flora richness in other regions, the richness of flora was lower than that of the Xupu Simeng Wetland and the Ruyuan Nanshuihu Wetland, but higher than that of other wetlands. In general, the flora richness was relatively high.

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.

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.

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 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.

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.

In March and September 2022, shrimp resources were investigated in six mangrove wetlands in Guangdong area in the Guangdong-Hong Kong-Macao Greater Bay Area, and the composition and diversity of shrimp communities in the region were analyzed by species relative importance index, biodiversity index, species similarity index and multivariate statistical analysis. The results showed that the 8 357 shrimps collected belonged to 37 species, 9 families and 2 orders, among which the dominant species in spring were Upogebia carinicauda, Metapenaeus ensis, Parapenaeopsis hardwickii, Litopenaeus vannamei and Fenneropenaeus penicillatus, while in autumn were Upogebia carinicauda, Metapenaeus ensis and Parapenaeopsis hardwickii. The average number of shrimp caught in the six mangrove wetlands in the two seasons ranged from 237~1 508, with the biggest number from the Jiangmen Zhenhai Bay Mangrove Wetland Park, and the smallest number from the Zhongshan Cuiheng National Wetland Park. The average fresh mass of shrimp was 1 315.2~8 188.4 g, among which mass from the Jiangmen Zhenhai Bay Mangrove Wetland Park was the largest, and the Guangzhou Nansha Wetland Park was the smallest. The average number of shrimp species was 9~26 species, with the Jiangmen Zhenhai Bay Mangrove Wetland Park having the most species, and the Guangzhou Nansha Wetland Park the least. The Shannon-Wiener diversity index was 1.583~2.669, with the Huizhou Huidong Mangrove Nature Reserve, the Jiangmen Bay Mangrove Wetland Park as the highest, and the Guangzhou Nansha Wetland Park as the lowest. The Margalef species richness index of 1.193~3.010 was obtained, with the Jiangmen Zhenhai Bay Mangrove Wetland Park as the highest, the Zhongshan Cuiheng National Wetland Park as the lowest. The Pielou evenness index was 0.740~0.923, the Huizhou Huidong Mangrove Nature Reserve as the top, and the Guangzhou Nansha Wetland Park at the bottom. The composition, abundance and species diversity index of shrimp in the same mangrove wetland did not differ much between spring and autumn. The results of cluster analysis showed that the shrimp communities in four large mangrove wetlands, namely Jiangmen Zhenwan Mangrove Wetland Park, Huizhou Huidong Mangrove Nature Reserve, Zhuhai Qi'ao Island Mangrove Nature Reserve, and Shenzhen Futian Mangrove National Nature Reserve, were classified into the same group. The shrimp communities in the two smaller mangrove wetlands, the Guangzhou Nansha Wetland Park and the Zhongshan Cuiheng National Wetland Park, were of the other group. The similarity analysis test (One-Way ANOSIM) further revealed the significant differences in shrimp community structure between the two groups of mangrove wetlands (Global R=0.879, p=0.002). BIOENV analysis showed that chlorophyll a content, dissolved oxygen content, pH and mangrove area were important environmental factors affecting shrimp abundance (ρ=0.877), and mangrove area had the greatest impact on shrimp abundance.

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 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.

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.

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 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.

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.

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.

From May to November 2022, a comprehensive monitoring of zooplankton and water environmental factors in the Xiaoxingkai Lake was conducted to investigate the relationship between zooplankton abundance and water environmental factors. Additionally, the trophic state of the water was assessed using the comprehensive trophic level index method. The results indicated significant seasonal variations in zooplankton abundance, with the highest abundance observed in spring, followed by summer, autumn, and winter. The trophic level index was highest in the area significantly influenced by human activities (Management Committee area), whereas the lake center, with minimal human impact, exhibited the lowest trophic level index. Seasonal variations in the comprehensive trophic level index were observed, ranked from highest to lowest as autumn, summer, spring, and winter. The overall trophic level index for the Xiaoxingkai Lake was 49.96, categorizing the lake as mesotrophic. Pearson correlation analysis and redundancy analysis revealed that the primary environmental factors influencing zooplankton abundance in spring and summer were total phosphorus concentration, water transparency, temperature, total nitrogen concentration, and turbidity. In autumn, the key factors were chloride concentration, pH, chlorophyll-a concentration, water transparency, and turbidity, while in winter, chlorophyll-a concentration was the dominant factor. There were significant differences in the correlations between the abundance of different types of zooplankton and environmental factors.

In order to explore the characteristics and influencing mechanisms of CH₄ production potential in different types of wetlands in Jiangsu Province, and to accurately assess CH₄ emissions and their importance in carbon emission estimation, the inland lake wetlands, river wetlands, and coastal wetlands were selected as the research objects. Soil samples from different vegetation types in lakes (Hongze Lake, Taihu Lake), rivers (Huaihe River, Yangtze River), and coastal areas were collected and the CH₄ production potential was quantified through indoor cultivation experiments. The relationship between CH₄ production potential and soil organic carbon, dissolved organic carbon, total nitrogen, ammonium nitrogen, nitrate nitrogen, and soil pH, was analyzed. The results showed that there were significant differences in physicochemical properties of soils among different types of wetlands, with lake wetlands having significantly higher contents of soil organic carbon, dissolved organic carbon, total nitrogen, ammonium nitrogen, compared to river wetlands and coastal wetlands, while only Hongze Lake wetland soil exhibited a discernibly higher nitrate nitrogen content than other wetlands. The CH₄ production potentials in soils of lake wetlands, river wetlands, and coastal wetlands were 0.048-4.556 μg/(g·d), 0.005-0.145 μg/(g·d), and 0.002-0.348 μg/(g·d), respectively. The soil CH₄ production potential in lake wetlands was the highest, being 9.6-31.4 times that of river wetlands and 13.0-24.0 times that of coastal wetlands. Accordingly, the CH₄ production potential in different types of wetland soils in Jiangsu Province ranked as follows: lake wetlands>coastal wetlands>river wetlands. The main influencing factor for CH₄ production potential in lake wetland soils was the dissolved organic carbon content, whereas the total nitrogen content was the predominant factor influencing CH₄ production potential of river wetlands, and the CH₄ production potential of coastal wetlands was mainly affected by the dissolved organic carbon and ammonium nitrogen contents.

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.

Mangrove ecosystem is an important coastal blue carbon ecosystem. To reveal the variation and dimensional correlation of leaf functional traits of young mangrove plantation can help us understand the adaptation mechanism of young mangrove to changing environment and its community assembly rules. A total of 9 932 leaves were collected from 764 plant individuals in the mangrove restoration area of Anle Village, Xichang Town, Beihai City, and leaf thickness, leaf area, leaf volume, specific leaf area, leaf dry matter content, and leaf tissue density of each leaf were measured. The variation sources and correlations of leaf functional traits at leaf, individual, and species scales were explored using generalized linear models, varcomp function, principal component analysis, and pearson correlation analysis. The results showed that the coefficient of variation of leaf functional traits was the largest at leaf scale and the smallest at species scale. The variation of all leaf functional traits mainly came from species scale. the first two principal component axes explained 75.6%, 72.8% and 96.8% of the total variance of the 6 functional traits, respectively. The results showed that the variation coefficient of the six leaf functional traits was highest at the leaf scale and lowest at the species scale. The variation of leaf thickness, leaf area, leaf volume, specific leaf area, leaf dry matter content, and leaf tissue density mainly originated from species scale. Principal component analysis results showed at the leaf, individual and species scales, the first two principal component axes explained 75.6%, 72.8% and 96.8% of the total variance of the six functional traits, respectively. At the three scales, there leaf thickness, leaf area, and leaf volume were significantly positive correlated, while specific leaf area, leaf dry matter content, and leaf tissue density were mainly negatively correlated with other traits.

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.

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.

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.

In order to investigate the adsorption and desorption characteristics of ammonium nitrogen by soils in the Hani terraces in Yunnan, soil samples were collected at different altitudes (upper and lower terraces) and depths (0-20, >20-40, >40-60 and >60-80 cm) in the dry season (November) and wet seasons June), respectively. The adsorption and desorption thermodynamics and kinetic sequential batch experiments of ammonium nitrogen were carried out, and the adsorption-desorption critical concentration of soil ammonium nitrogen were calculated by using the kinetic models and isothermal thermodynamic models. The results showed that the kinetic curves of ammonium nitrogen adsorption in the Hani terraces could be fitted by quasi-first-order equations. The ammonium nitrogen adsorption capacities of the lower terraced soils were more than 12% higher than those of the upper terraced soils in different months. The ammonium nitrogen adsorption capacities of soils at different altitudes in June were more than 52% higher than those in November, and the ammonium nitrogen adsorption capacities increased gradually with the soil depths. The thermodynamic curves of ammonium nitrogen adsorption could be fitted by Langmuir's equation. The maximum adsorption capacity of ammonium nitrogen increased gradually with the increase of soil depth, and those in the lower terraces were more than 19% higher than those in the upper terraces in different months. The maximum adsorption capacities of ammonium nitrogen at different altitudes in June were more than 67.5% higher than those in November. The desorption thermodynamic curve of ammonium nitrogen in Hani terraced soil can be fitted using the Langmuir equation. The maximum desorption of ammonium nitrogen in the lower terraced fields is greater than that in the upper terraced fields in different months. The desorption capacity of ammonium nitrogen in soils at different altitudes in November was stronger than that in June. The thermodynamic curves of ammonium nitrogen desorption in the Hani terraced soils could be fitted by the Langmuir equation. The maximum ammonium nitrogen desorption capacity in the lower terrace was greater than that in the upper terrace in different months. The maximum ammonium nitrogen desorption capacity in soils at different elevations in November was greater than that in June. The critical adsorption concentration of ammonium nitrogen in the Hani terrace was lower than that in the overlying water, and as a ‘sink’ for ammonium nitrogen, it could effectively adsorb ammonium nitrogen. Moreover, the adsorption capacity of soils for ammonium nitrogen in June was greater than that in November, and the ammonium nitrogen adsorption capacity in the lower terraced soil was greater than that in the upper terraced soil. The Hani terraced wetlands play an important role in preventing surface source pollution and eutrophication of wetlands and lower rivers, and enhancing the ecological function of wetland ecosystems. The findings can provide references for the sustainable development of terraced wetlands.

Three kinds of sampling sites of mudflat bare land, natural grassland and abandoned farmland were selected in Taohuayu floodplain of the Henan section of Yellow River. Soil samples at a depth of 0-10 cm were analyzed for the activity of four hydrolytic enzymes (N-acetyl-β-D-glucosaminidase, β-1,4-xylosidase, cellobiohydrolase, and leucine aminopeptidase) and one oxidase (peroxidase), as well as for the physicochemical properties of the soil under the three different land use types. The results showed that the mean activities of the four hydrolytic enzymes were 0.82 nmol/(h·g) for N-acetyl-β-D-glucosaminidase, 0.83 nmol/(h·g) for β-1,4-xylosidase, 1.69 nmol/(h·g) for cellobiohydrolase, and 3.24 nmol/(h·g) for leucine aminopeptidase. Compared to mudflat bare land and abandoned farmland soils, the activities of four hydrolytic enzymes were significantly higher in natural grassland soils. In contrast, peroxidase activity was highest in mudflat bare land soils, exceeding that in natural grassland and abandoned farmland soils. Correlation and redundancy analyses revealed that the activity of soil hydrolytic enzymes was significantly positively correlated with soil total carbon and total nitrogen contents, but significantly negatively correlated with soil pH. Peroxidase activity was positively correlated with soil ammonium and nitrate nitrogen contents. In the Henan section of Yellow River, natural restoration of floodplain promoted the activity of soil hydrolases and contributed to the improvement of soil quality.

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.

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.

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.

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.

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 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.

A field investigation of Brasenia schreberi in the high-altitude wetlands of southern Hunan was conducted in the Mangshan National Nature Reserve, Yizhang County, Chenzhou City, and the Wild Brasenia Habitat Protection Area of Shangdong Village, Guidong County. The study analyzed the characteristics of wild Brasenia communities, their diversity, and the relationship between community characteristics and water environmental factors, aiming to identify the key water environmental factors influencing the characteristics of wild Brasenia communities. The results indicated that the associated species in the three protection areas, Mangshan Museum, Langpan Lake in Mangshan, and Shangdong Village in Guidong were relatively few, with dominant species including Alisma orientale, Scirpus triqueter, Nymphaea tetragona, and Caldesia grandis. The diversity index of cultivated Brasenia communities in the Mangshan Museum was lower than that of wild Brasenia communities. Nitrogen content in the water was identified as the primary factor influencing the characteristics and community diversity level of Brasenia. During the introduction and restoration of Brasenia, attention should be paid to nitrogen content, water temperature, and conductivity. These findings provide insight into the adaptive mechanisms between Brasenia and its environment and offer a reference for the introduction, expansion, and habitat restoration of Brasenia.

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.

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.

Bird diversity is an important component of wetland ecosystems. From February 2022 to March 2023, bird surveys were conducted in four habitats (lake, farmland, shelterbelt, and pond) of Anhui Yingshang Balihe Provincial Nature Reserve using sample point and line transects. Multidimensional diversity was applied to analyze the spatiotemporal patterns of avian communities. Throughout this period, the park hosted 138 distinct bird species, totaling 35 838 individuals. Among these, 2 species was designated under the National Key Protected Wildlife Category I and 15 under Category II, 1 critically endangered species and 5 vulnerable species listed on the IUCN Red List. According to the analysis, there were significant differences in bird diversity among the four types of habitats in spring, the multidimensional diversity of bird species was higher in the farmland habitat during summer. Lake habitats had their highest species richness (38.00), functional richness (128.64), and phylogenetic diversity (1 264.71) in autumn, the species richness (39.67), functional richness (69.30), and phylogenetic diversity (1 254.96) of lake habitats were significantly higher than those of other habitats in winter. In different habitats, the Shannon-Wiener index (2.32), taxonomic diversity (67.53), functional richness (128.64), and phylogenetic diversity (1 264.71) exhibited peak values in the lake habitat during autumn, while species richness (39.67) and the number of individuals (17 592) reached their zenith in winter. Within the farmland habitat, avian species richness (28.33), Shannon-Wiener index (2.77), functional richness (48.81), and phylogenetic diversity (976.28) attained their highest levels in summer and lowest in winter. Notably, the Shannon-Wiener index (2.44), Simpson index (0.89), and Pielou index (0.86) in the shelter forest were markedly elevated during autumn compared to the other three seasons. Meanwhile, species richness (19.67) was maximal in winter and minimal in spring within the pond habitat. The observation in the reserve during a single survey revealed that both the Common Pochard and the Great Cormorant exceeded 3 000 individuals, surpassing 1% of the population of these species along the East Asia-Australia flyway, meeting the criteria for an internationally important wetland. Additionally, the survey discovered 2 new records, the Long-tailed Duck and the Common Goldeneye, in Anhui. Anhui Yingshang Balihe Provincial Nature Reserve provided an excellent foraging and habitat environment for birds, particularly waterbirds, serving as a crucial stopover and wintering site along the East Asia-Australia flyway.

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.