Search Results (13)

Mercury (Hg) contamination in soils poses significant environmental risks. In response, various nature-based solutions (NbSs) have been developed and studied in the past to treat mercury along with other heavy metals from both point and nonpoint sources. However, various land uses present uncertainties in mercury mobility and treatment efficiency, affecting the scalability of NbS systems. In this study, a systematic review of peer-reviewed articles addressing mercury pollution in NbS soils was conducted. Results revealed that lakeside environments and mining areas are key Hg accumulation zones due to hydrological connectivity and anthropogenic pressures. Constructed wetlands were the most studied NbSs, where those with Acorus calamus and Aquarius palifolius as the main vegetation achieved >90% Hg removal efficiencies. Although NbSs achieved high Hg removal, anaerobic conditions were found to promote MeHg formation, a critical drawback. Moreover, biochar demonstrated potential for immobilizing Hg and reducing bioavailability, though certain types increased MeHg formation under specific redox conditions. Overall, the study highlighted the need for site-specific design, long-term field evaluation, and multidisciplinary strategies to optimize NbS performance for mercury removal. Furthermore, future research on the scalability of mercury-treating NbSs across diverse land uses is recommended to address mercury risks and improve effectiveness. Full article

Global warming has intensified the changes in wetland carbon cycling processes, and the cbbL gene, which plays a key role in carbon fixation, is significantly affected by warming. Therefore, we set up open-top chamber warming and natural controls and used amplicon sequencing to investigate the response of the cbbL carbon-fixing microbial community in the alpine lakeshore wetland to warming. We found that after the warming treatment, the relative abundances of Actinobacteria and Chlorophyta increased, while the relative abundance of Cyanobacteria decreased (p < 0.05). Soil temperature and moisture were the most significant factors influencing the cbbL carbon-fixing microbial community in the lakeshore wetland. Deterministic processes dominated the community assembly of carbon-fixing microbes under warming conditions. Additionally, warming enhanced both cooperative and competitive interactions among carbon-sequestering microorganisms while reducing soil moisture availability and increasing environmental stress, leading to a decrease in the modularity of microbial communities. In summary, warming reduced the carbon sequestration potential of lakeside wetlands but favored the interactions among carbon-sequestering microorganisms. Full article

Carbon-sequestering microorganisms play an important role in the carbon cycle of wetland ecosystems. However, the response mechanism of carbon-sequestering microbial communities to wetland type changes and their relationship with soil carbon remain unclear. To explore these differences and identify the main influencing factors, this study selected marsh wetlands, river wetlands and lakeside wetlands around Qinghai Lake as research subjects. High-throughput sequencing was employed to analyze the functional gene cbbM of carbon-sequestering microorganisms. The results revealed that the alpha diversity of cbbM carbon-sequestering microorganisms mirrored the trend in total carbon content, with the highest diversity observed in marsh wetlands and the lowest in lakeside wetlands. The dominant bacterial phylum was Proteobacteria, with prevalent genera including Thiothrix, Acidithiobacillus, and Thiodictyon. Acidithiobacillus served as a biomarker in lakeside wetlands, while two other genera were indicative of marsh wetlands. The hierarchical partitioning analysis indicated that the diversity of cbbM carbon-fixing microorganisms was primarily influenced by the total nitrogen content, while the community structure was significantly affected by the soil total carbon content. Moreover, an increased soil temperature and humidity were found to favor the carbon fixation processes of Thiomicrospira, Thiomonas, Polaromonas, and Acidithiobacillus. In summary, changes in wetland types seriously affected the characteristics of cbbM carbon sequestration in microbial communities, and a warm and humid climate may be conducive to wetland carbon sequestration. Full article

The soil carbon storage in the Qinghai–Tibet Plateau wetlands is affected by microbiota and wetland types, but the response mechanisms of carbon sequestration microorganisms on the Qinghai–Tibet Plateau to different wetland types are still poorly described. To explore the differences in carbon sequestration microbial communities in different wetlands and the main influencing factors, this study took a marsh wetland, river source wetland and lakeside wetland of Qinghai Lake as the research objects and used high-throughput sequencing to study the functional gene, cbbL, of carbon sequestration microorganisms. The results showed that the dominant bacterial group of carbon sequestration microorganisms in marsh and river source wetlands was Proteobacteria, and the dominant bacterial group in the lakeside wetland was Cyanobacteria. The alpha diversity, relative abundance of Proteobacteria and total carbon content were the highest in the marsh wetland, followed by the river source wetland, and they were the lowest in the lakeside wetland. In addition, the physical and chemical characteristics of the three wetland types were significantly different, and the soil temperature and moisture and total carbon content were the most important factors affecting the community structures of carbon-sequestering microorganisms. There was little difference in the total nitrogen contents between the marsh wetland and river source wetland. However, the total nitrogen content was also an important factor affecting the diversity of the carbon sequestration microbial community. In summary, the wetland type significantly affects the process of soil carbon sequestration. Compared with the riverhead and lakeside wetlands, the marsh wetland has the highest carbon storage. Full article

Spontaneous vegetation plays an important role in protecting urban biodiversity and the maintenance of urban ecosystems. In this study, we investigated the species diversity, life-form composition, origin, flowering season, and spatiotemporal distribution of spontaneous vegetation in the exhibition and education area of Tangdao Bay National Wetland Park using the quadrat survey method. There were 65 spontaneous association types and 210 spontaneous plant species, belonging to 151 genera and 44 families. The associations and species of spontaneous plants in roadside habitats were found to be the highest. In addition, many species were found in woodland and lakeside habitats, whereas the lowest number of species were found in coastal habitats. The life-form composition included 76 annual and 94 perennial herb species. These plants were of various origins. There were 160 native, 9 domestically introduced, 2 introduced alien, and 39 invasive alien plant species, which predominantly came from the Americas. A single peak was observed from March to November for the spontaneous plant species that were in their growing season, including those of different life forms and from various sources. The same was true for spontaneous plants in their flowering season. During their growing season, the number of spontaneous plant species was highest during September and, during their flowering season, the number of species was highest in July. From April to September, the Shannon–Wiener diversity index for spontaneous vegetation in the roadside habitat was the highest, followed by those for the woodland and lakeside habitats, and that of the coastline habitat was the lowest. The monthly average Shannon–Wiener diversity index for spontaneous plant associations in the four habitats also varied, with a single peak. The diversity of spontaneous plants and alien invasive plants in Tangdao Bay National Wetland Park is high. The wise use and protection of spontaneous flowering plants with long ornamental seasons can effectively reduce the maintenance costs, resource consumption, and energy requirements of the park. Spontaneous plants should also be managed to reduce the harm from alien invasive plants in the park, and alien invasive plants should be removed from the park during their flowering seasons. Full article

There is a huge carbon pool in the lakeside, which is sensitive to environmental changes and can very easily be transformed into a carbon source as land from the lake is reclaimed. In this paper, West Mauri Lake was employed as a case study to examine soil organic carbon (SOC) and its controlling factors along the lakeside. Four transects of land use (i.e., vegetation) types along the landward lakeside were identified as the fluctuation zone, the beach zone, the mesozoic farmland rewetting zone and the xerophytic farmland rewetting zone. With the increase in soil depth, SOC in the lakeside decreased significantly (p < 0.05). SOC had an obvious seasonal variation (p < 0.001), ranking in order: winter (December) > spring (February) > summer (May). Among the aforementioned transects, SOC density differed significantly (p < 0.05), showing a significant increasing trend. Pearson correlation indicated that most soil physiochemical factors showed a significant correlation with SOC (p < 0.01), except total chromium, total copper, total zinc and total phosphorus. The relationship between SOC density and total nitrogen (N) has an obvious “S” curve, and total N accounts for 81% of the variation of SOC, suggesting that total N is the main controlling factor of SOC in the lakeside. The significant difference in SOC along the different vegetation (land use) types implied that land use affects the SOC in the lakeside. The long-term accumulation of N fertilizer after the man-made reclamation and aquaculture obviously controls SOC in the lakeside of West Mauri Lake. Full article

Soil organic carbon (SOC), as the largest carbon pool on the land surface, plays an important role in soil quality, ecological security and the global carbon cycle. Multisource remote sensing data-driven modeling strategies are not well understood for accurately mapping soil organic carbon. Here, we hypothesized that the Sentinel-2 Multispectral Sensor Instrument (MSI) data-driven modeling strategy produced superior outcomes compared to modeling based on Landsat 8 Operational Land Imager (OLI) data due to the finer spatial and spectral resolutions of the Sentinel-2A MSI data. To test this hypothesis, the Ebinur Lake wetland in Xinjiang was selected as the study area. In this study, SOC estimation was carried out using Sentinel-2A and Landsat 8 data, combining climatic variables, topographic factors, index variables and Sentinel-1A data to construct a common variable model for Sentinel-2A data and Landsat 8 data, and a full variable model for Sentinel-2A data, respectively. We utilized ensemble learning algorithms to assess the prediction performance of modeling strategies, including random forest (RF), gradient boosted decision tree (GBDT) and extreme gradient boosting (XGBoost) algorithms. The results show that: (1) The Sentinel-2A model outperformed the Landsat 8 model in the prediction of SOC contents, and the Sentinel-2A full variable model under the XGBoost algorithm achieved the best results R² = 0.804, RMSE = 1.771, RPIQ = 2.687). (2) The full variable model of Sentinel-2A with the addition of the red-edge band and red-edge index improved R² by 6% and 3.2% over the common variable Landsat 8 and Sentinel-2A models, respectively. (3) In the SOC mapping of the Ebinur Lake wetland, the areas with higher SOC content were mainly concentrated in the oasis, while the mountainous and lakeside areas had lower SOC contents. Our results provide a program to monitor the sustainability of terrestrial ecosystems through a satellite perspective. Full article

Niaodao, a lakeside wetland, was used as the focus of this study to investigate the effect of rainfall changes on the greenhouse gas fluxes of wetland ecosystems. Wetland plots with different moisture characteristics (+25%, −25%, +75%, and −75% rainfall treatments and the control treatment (CK)) were constructed to observe in situ field greenhouse gas emissions at 11:00 and 15:00 (when the daily mean values were similar) in the growing season from May to August 2020 by static chamber–gas chromatography and to investigate the responses of wetland greenhouse gases to different rainfall treatments. The results showed the following: (1) The carbon dioxide (CO₂) flux ranged from −49.409 to 374.548 mg·m⁻²·h⁻¹. The mean CO₂ emission flux was greater at 11:00 than at 15:00, and the +25% and +75% treatments exhibited substantially higher CO₂ emissions. In addition, the CO₂ flux showed a small peak at the beginning of the growing season when the temperature first started to rise. All treatments showed the effect of the CO₂ source, and their effects were significantly different. (2) The methane (CH₄) flux ranged from −213.839 to 330.976 µg·m⁻²·h⁻¹ and exhibited an absorption state at 11:00 and an emission state at 15:00. The CH₄ emission flux in August (the peak growing season) differed greatly between treatments and was significantly negatively correlated with the rainfall amount (p < 0.05). (3) The nitrous oxide (N₂O) flux ranged from −10.457 to 16.878 µg·m⁻²·h⁻¹ and exhibited a weak source effect throughout the growing season, but it was not significantly correlated with soil moisture; it was, however, negatively correlated with soil temperature. (4) The different treatments resulted in significant differences in soil physical and chemical properties (electrical conductivity, pH, total soil carbon, and total soil nitrogen). The rainfall enhancement treatments significantly improved soil physical and chemical properties. Full article

Human activity is the major factor driving the wetland degradation in shallow lakes. Human exploitation of lake wetlands alters the habitats of wintering waterbirds, and, in turn, waterbird diversity in the shallow lakes. In the present study, we surveyed species composition, abundance, and habitat characteristics of waterbirds in three types of wetland habitats (natural lakeside wetlands, paddy fields, and aquaculture ponds) at Caizi Lake, a shallow lake in the middle and lower Yangtze River during the wintering period, and investigated the effects of habitat change driven by human activity on the diversity of wintering waterbirds. There were significant differences in species composition and abundance among the three wetland habitats (natural lakeside wetlands, aquaculture ponds, and artificial paddy fields); however, there were no significant differences among the habitats with respect to the number of waterbirds. The numbers of overwintering waterbird species and waterbird individuals in aquaculture ponds and lakeside wetlands were significantly higher than the numbers in the paddy fields, indicating that wintering waterbirds prefer natural lake wetlands and aquaculture ponds. Principal component analysis of the three wetland habitat types revealed that factors influencing waterbird diversity include wetland area, vegetation cover, water level, and degree of human interference. Therefore, minimizing human interference and ensuring suitable habitats at specific periods could facilitate the maintenance of waterbird diversity. Full article

The biodiversity of fungi, which are extremely important in maintaining the ecosystem balance in alpine lakeside wetlands, has not been fully studied. In this study, we investigated the fungal communities of three lakeside wetlands from different altitudes in the Qinghai–Tibet Plateau and its edge. The results showed that the fungi of the alpine lakeside wetland had higher species diversity. Functional annotation of fungi by FUNGild software showed that saprophytic fungi were the most abundant type in all three wetlands. Further analysis of the microbial phylogenetic molecular ecological network (pMEN) showed that saprophytic fungi are important species in the three wetland fungal networks, while symbiotic fungi and pathotrophic fungi have different roles in the fungal networks in different wetlands. Community diversity was high in all three lakeside wetlands, but there were significant differences in the composition, function and network structure of the fungal communities. Contemporary environmental conditions (soil properties) and historical contingencies (geographic sampling location) jointly determine fungi community diversity in this study. These results expand our knowledge of fungal biodiversity in the alpine lakeside wetlands. Full article

Due to earthquakes and large-scale exploitation of oil, gas, groundwater, and coal energy, large-scope surface deformation has occurred in Songyuan City, Jilin Province, China, and it is posing a serious threat to sustainable development, including urban development, energy utilization, environmental protection, and construction to improve saline–alkali land. In this study, we selected the Chagan Lake region, which is located in Songyuan City, as our research area. Using temporarily coherent point synthetic aperture radar interferometry (TCPInSAR), we obtained a time series of land surface deformation and the deformation rate in this area from 20 ALOS PALSAR images from 2006 to 2010. The results showed that the deformation rate in the Chagan Lake region ranged from −46.7 mm/year to 41.7 mm/year during the monitoring period. In three typical land cover areas of the Chagan Lake region, the subsidence in the wetland area was larger than that in the saline–alkali area, while the highway experienced a small uplift. In addition, surface deformation in lakeside areas with or without dykes was different; however, as this was mainly affected by soil freeze–thaw cycles and changes in groundwater level, the deformation showed a negative correlation with temperature and precipitation. By monitoring and analyzing surface deformation, we can provide a data reference and scientific basis for sustainable ecological and economic development in the Chagan Lake region and adjacent areas. Full article

Wetland ecosystems are one of the three great ecosystems on Earth. With a deepening of research on wetland ecosystems, researchers have paid more and more attention to wetland ecosystem services such as flood mitigation, climate control, pollution prevention, soil-erosion prevention, biodiversity maintenance, and bio-productivity protection. This study focuses on a lakeside wetland ecosystem in Hefei, a city in central China, and estimates the value of ecosystem services such as material production, air purification, water conservation, biodiversity, recreation, species conservation, education and scientific research. We adopted the market value method, carbon tax method, afforestation cost method, shadow engineering method and contingent value method (CVM) using questionnaire survey data during the study period. The results show that the total value of the ecosystem services of Lakeside Wetland Park was 144 million CNY in 2015. Among these services, the value of society service is the maximum at 91.73 million CNY, followed by ecological service and material production service (42.23 million CNY and 10.43 billion CNY in 2015 respectively). When considering wetland ecosystems for economic development, other services must be considered in addition to material production to obtain a longer-term economic value. This research reveals that there is scope for more comprehensive and integrated model development, including multiple wetland ecosystem services and appropriate handling of wetland ecosystem management impacts. Full article

Our study concerns the development of marginal zone of Lake Suchar Wielki (Wigry National Park). This humic lake is characterised by mire occurrence in its marginal zone, covered with a floating mat spreading on water surface. Biogenic sediments (peat archive) present in lakeside allow recognising the thousands years’ development pattern of lake surrounded by mire. The wetland records were analysed for plant macroremains, degree of peat decomposition, sediment geochemical features along with age assessment. Morphological characteristics of the catchment were integrated with the wetland records. Our research showed that after the lake origin in the Allerod, accumulation in its marginal zone was interrupted, which was probably connected with high precipitation in the past. Slope processes could be possible. Stabilisation of environmental conditions took place in the younger Holocene. Despite these perturbations marginal zone of the lake was permanently terrestrial in character, as indicated by values of atomic C:N ratio. Full article