Natural Wetlands Research Articles

Advancements in mapping areas suitable for wetland habitats across the conterminous United States

Wetland habitats provide critical ecosystem services to the surrounding landscape, including nutrient and pollutant retention, flood mitigation, and carbon storage. Wetland connectivity to water bodies and related ecosystems is critical in habitat sustainability, but there are limited resources for landscape-level wetland planning. Considering the network connectivity of an ecosystem type can derive different benefits to the natural and built environment, as well as human health. The value that wetlands provide, along with incentive programs and conservation goals mandated by the government require new and improved wetland spatial data. Utilizing high quality, publicly available data, this study finds that the amount of land in the United States that could support built or restored wetlands is more than double the area of mapped existing wetlands.This study uses 17 input variables (i.e., features extracted from remotely sensed data and auxiliary datasets) at the 10-m resolution and the National Wetlands Inventory to train a random forest model to identify areas that may support a wetland habitat, or potential wetland areas. Models were calculated for each of 18 two-digit hydrologic units that encompass the conterminous United States, and model overall accuracy ranged from 78.0 % to 89.8 %. The models predicted that 21.1 % of the conterminous United States can be categorized as potential wetland area.Selecting input variables to predict areas with wetland potential, rather than to identify existing wetlands, using the random forest algorithm can be transferred to other locations, scales, and ecosystem types. Visualizing potential wetland areas using input data at the 10-m resolution and enhanced methodology improves previous work, as even slight changes in topography, soils, and landscape features can determine ecosystem connections. This product can be used to better place wetland restoration projects to serve ecosystem- and community-wide health by ensuring ecosystem success and targeting areas that face increased climate change impacts.

A long-term (1984–2021) wetland classification dataset for the Yangtze River Basin from continuous Landsat image collections

The wetlands along the Yangtze River Basin (YRB) have provided a variety of ecological and economic benefits. However, the lack of a long-term wetland classification dataset with comprehensive wetland categories has created in a barrier to evaluating the long-term variations of YRB wetlands for their habitat health, carbon storage, greenhouse gas emissions, and ecosystem service capacity. Therefore, this study aimed to generate a wetland classification dataset for the YRB covering the time period from 1984 to 2021. The dataset named Long-Term Wetland Classification Dataset for YRB (LTWCD_YRB) was created using a Random Forest machine learning classifier on Google Earth Engine with 30 m resolution Landsat 5, 7, 8 muti-spectral images. The maps of LTWCD_YRB demonstrated the spatial distribution, annual variability, and seasonal cycle of nine wetland categories in the extent, and the total validation accuracy can reach 85 %. The LTWCD_YRB indicates that the total wetland area of the YRB in 2021 was larger than that in 1984, with a constant increase in human-made wetlands and fluctuating natural wetlands. Aquaculture ponds expanded the most by 4,987 km2, while inland marshes in the source region exhibited the most fluctuations. Seasonal changes in wetlands were prominent in the Poyang Lake Basin, Dongting Lake Basin, and YRB source region. Human activities were found to be more dominant than natural driving forces in affecting wetlands. The LTWCD_YRB offers a consistent agreement of wetland area variations with the other satellite-based wetland datasets in the YRB, making it valuable for researchers, policymakers, and stakeholders to better understand the YRB wetlands and to support sustainable wetland management practices.

Artificial wetlands providing space gain for the suitable habitat of coastal Pied Avocet

A large number of artificial wetlands have replaced natural wetlands along waterbird migration routes to supply breeding, resting and feeding grounds for waterbirds. Effective identification of potential artificial wetlands that could serve as suitable habitats for waterbirds can provide important reference for field investigation and waterbird conservation. In this study, the habitat suitability of the Pied Avocet in the Yellow River Delta (YRD), China was simulated with the optimized MaxEnt model based on its occurrence records and environmental variables. The results showed that the MaxEnt model could well predict the habitat suitability of the Pied Avocet (Recurvirostra avosetta) in the YRD. The suitable habitats were distributed in the specific areas of the coastal zone, and artificial wetlands such as salt pans and mariculture ponds were the main components in the high-suitability area. The top three environmental factors affecting habitat selection were the land use and land cover (LULC), distance to the coastline and normalized difference vegetation index (NDVI). This paper emphasizes the role of artificial wetlands in providing suitable habitat for waterbirds. In order to better protect the habitat of waterbirds and alleviate human-bird conflict in the YRD, some targeted suggestions were put forward for the management gap of artificial wetlands. This study has strong practical significance for the protection and habitat management of waterbirds in the YRD. The methodology we employed is transferable to other wetlands, where efficient management is inhibited due to a lack of comprehensive field investigations.

Phytoremediation of metals in oil sands process affected water by native wetland species

Process affected water and other industrial wastewaters are a major environmental concern. During oil sands mining, large amounts of oil sands process affected water (OSPW) are generated and stored in ponds until reclaimed and ready for surface water discharge. While much research has focused on organics in process waters, trace metals at high concentrations may also pose environmental risks. Phytoremediation is a cost effective and sustainable approach that employs plants to extract and reduce contaminants in water. The research was undertaken in mesocosm scale constructed wetlands with plants exposed to OSPW for 60 days. The objective was to screen seven native emergent wetland species for their ability to tolerate high metal concentrations (arsenic, cadmium, copper, chromium, copper, nickel, selenium, zinc), and then to evaluate the best performing species for OSPW phytoremediation. All native plant species, except Glyceria grandis, tolerated and grew in OSPW. Carex aquatilis (water sedge), Juncus balticus (baltic rush), and Typha latifolia (cattail) had highest survival and growth, and had high metal removal efficiencies for arsenic (81–87 %), chromium (78–86 %), and cadmium (74–84 %), relative to other metals; and greater than 91 % of the dissolved portions were removed. The native plant species were efficient accumulators of all metals, as demonstrated by high root and shoot bioaccumulation factors; root accumulation was greater than shoot accumulation. Translocation factor values were greater than one for Juncus balticus (chromium, zinc) and Carex aquatilis (cadmium, chromium, cobalt, nickel). The results demonstrate the potential suitability of these species for phytoremediation of a number of metals of concern and could provide an effective and environmentally sound remediation approach for wastewaters.

Analysis of methane emission characteristics and environmental response in natural wetlands

Wetlands are the most important natural source of methane (CH4) emissions. Apparent wetland CH4 emissions depend largely on the balance between CH4 production and oxidation. Wetland plants play an important role in all processes. However, direct observations and side-by-side comparisons of CH4 emissions from wetlands with different vegetation types are lacking at the global scale. There is still a lack of clarity in characterizing the environmental response to CH4 emissions from wetlands with different vegetation types. Based on the FLUXNET-CH4 dataset and the Global Standard Soil Database, we analyzed the environmental response characteristics of CH4 emissions and clarified the important role of plants in CH4 emissions. We categorized wetlands into vascular plant wetlands (VPWs) and moss plant wetlands (MPWs). VPWs CH4 emissions were typically higher and more heterogeneous, whereas MPWs CH4 emissions were lower and less variable. When the water table is below the surface, VPWs still have high CH4 emission rates, while MPWs have CH4 emission rates close to zero. In addition, the temperature sensitivity of CH4 emissions from VPWs (Q10 = 2.26) is significantly higher than that of MPWs (Q10 = 1.71). Solar radiation was the main factor affecting CH4 emissions from VPWs, and temperature was the main factor affecting CH4 emissions from MPWs. Finally, our results of structural equation model suggested that soil and water environment, temperature, and plants all contribute to wetland CH4 emissions to varying degrees. These findings highlight the important role of wetland vegetation in CH4 emissions, which should be seriously considered to reduce uncertainty in the assessment of wetland CH4 emissions.

Nitrate and ammonium removal in constructed wetlands: Experimental insights and zero-dimensional numerical modeling

Constructed wetlands (CWs) have emerged as effective wastewater treatment systems, mimicked natural wetland processes but engineered for enhanced pollutant removal efficiency. Ammonium (NH4+) and nitrate (NO3−) are among common pollutants in wastewater, posing significant environmental and health risks. The primary objective of this study is to compares the performance of CWs using gravel and three sizes of natural pumice, along with phragmites australis, in horizontal and horizontal-vertical CWs for nitrate and ammonium removal in the complementary treatment of domestic wastewater. Additionally, the study aims to develop and validate a numerical model using MATLAB software to predict the removal efficiency of these pollutants, thereby contributing to the optimization of CW design and operation. The model operates as a zero-dimensional model based on the law of mass conservation, treating the wetland as a completely mixed reactor, thus avoiding complexities associated with solute movement in porous media. It accurately could predict removal efficiency of chemical, biochemical, and biological indicators while considering active and passive absorption mechanisms by plant uptake. Notably, the determination of coefficients in the model equation does not rely on potentially error-prone laboratory measurements due to sampling issues. Instead, optimization techniques alongside field data robustly estimate these coefficients, ensuring reliability and practicality. Results indicate that higher pollutant concentrations increase reaction rates, particularly enhancing CW efficiency in ammonium removal. Pumice, especially in larger sizes, exhibits superior absorption due to increased porosity and surface area. Overall, the model accurately predicts nitrates concentrations, demonstrating its potential for CW performance optimization and confirming the significance of effective pollutant removal strategies in wastewater treatment.

Hotspots of wetland loss to impervious surfaces in the conterminous United States

In this study, a first wall-to-wall comparison between the National Wetlands Inventory (NWI) and the National Land Cover Database (NLCD) was conducted across the entire conterminous United States (CONUS) to evaluate U.S. wetland loss conditions. Annually, around 26 km2 of wetlands are lost to impervious surfaces across the CONUS. Spatially, wetland loss is not evenly distributed, with 90 % of losses occurring in only 9 % of the land area, forming hotspots around expanding urban regions such as Houston, Jacksonville, and Naples. Over the past few decades, Florida experienced the highest wetland loss (5.73 km2/year) among all states, while Houston had the most wetland loss (2.54 km2/year) among all metropolitan regions. Stepwise multiple regression models identified population growth and its associated demand for new housing as the major drivers for wetland loss. Wetland loss per population increase is the highest (>15 m2/person) in most metropolitan regions around the East Coast and Gulf of Mexico. Unfortunately, current wetland loss hotspots will likely suffer further losses in future decades due to projected population growth, with Houston, Cape Coral, and Miami metropolitan regions having the greatest projected wetland loss of 89.15 km2, 34.35 km2, and 28.20 km2, respectively. This study has identified wetland loss hotspots and their drivers across the U.S. that were not possible in previous sample-based studies. The findings are critical in wetland management and protection across the U.S.

Key processes of carbon cycle and sink enhancement paths in natural wetland ecosystems in China

Key processes of carbon cycle and sink enhancement paths in natural wetland ecosystems in China

Freshwater wetlands for flood control: How manipulating the hydroperiod affects plant and invertebrate communities.

Thoughtfully managed hydroperiods in natural and artificial wetlands could potentially provide a combination of desirable flood control services and high ecological functions. To explore how managed freshwater wetlands typical of the Houston, Texas area would respond to different hydrological regimes that might occur if wetlands were drained in anticipation of a heavy rain that did not materialize, we conducted a mesocosm experiment with six flooding depths and seven drought durations, followed by seven months of recovery. We found that the speed in which mesocosms dried out was a function of initial water depth, with mesocosms initially set with greater water depths (30 cm) taking ~ 38 days to dry out versus zero days for wetlands that were completely drained. Individual plant species (14 species planted; 8 species common at the end of the recovery period) were affected by drought length, flooding depth, or their interaction, although details of these responses varied among the species. The composition of the plant community at the end of the drought period was strongly affected by drought length, and the effect of the drought length treatment persisted through seven months of post-drought recovery, with the 80- and 160-day drought treatments diverging most strongly from shorter drought treatments. Above- and below-ground biomass of plants was not affected by the treatments, but above-ground dead biomass (litter) decreased with increasing drought length. Densities of mosquito larvae, snails and tadpoles were temporally variable, and were affected more during the treatment period and early in recovery than after a disturbance event late in recovery. Our results indicate that managed wetlands in southeast Texas would be quite resilient to dry periods of up to 40 days in duration, especially if water was not completely drained at the beginning of the drought. In addition, many species would persist in managed wetlands even with droughts of up to 160 days. This indicates considerable potential for managing the hydroperiods of artificial detention ponds by retaining water longer to increase ecological function, with little to no loss of flood control services, and for managing the hydroperiods of natural wetlands by draining them in advance of anticipated rains to increase flood control services, with little to no loss of ecological function.

The impact mechanism of human activities on the evolution of coastal wetlands in the Liaohe River Delta

IntroductionThis study aims to investigate the impact of human activities on the evolution of coastal wetlands in the Liaohe River Delta. Understanding these impacts is crucial for the management, protection, and sustainable development of the ecological environment in the region.MethodsQuantitative analysis of the evolution of coastal wetlands along the Liaohe River from 1995 to 2020 using Landsat series remote sensing images. This study examines the changes in different landscapes and explores the impact of human activities on wetlands through methods such as land transfer matrix, landscape pattern index, and human activity hotspots.ResultsThe results show that the area of coastal wetlands in the Liaohe River Delta exhibited a fluctuating downward trend from 1995 to 2020. The eastern and western parts of the delta experienced greater disturbance to wetland landscapes due to human activities, while the northern and southern parts were mostly waters and reed lands with a smaller degree of human disturbance. Human activities have led to significant changes in farmland, ponds, rice paddies, construction land, and reed fields, thereby promoting the evolution of coastal wetlands.DiscussionThis article discusses the characteristics of landscape pattern evolution in the study area, as well as the impact of human interference, economy, policies, and other factors on it, and compares it with the evolution patterns of other coastal wetlands in China. The changes in the landscape pattern of the study area are mainly reflected in the reduction and fragmentation of natural wetland areas, which are closely related to human activities, especially the development of construction and agriculture. The main economic manifestation is that the increase in land demand due to economic and urban development has led to the transformation of natural wetlands into construction land and other artificial landscapes. The implementation of regulations such as the Wetland Protection Law has contributed to the rational use and ecological restoration of wetlands, and also reflects the influence of policy factors. Compared with other studies, coastal wetlands in China generally face issues of degradation and loss, mainly caused by human activities, but also affected by natural factors such as rising sea levels, changes in coastlines, and climate change.

Macroinvertebrate community dynamics following wetland restoration: Insights from taxonomic structure and functional feeding groups in response to water quality

Continuous wetland restoration initiatives in China are increasing, due to the global degradation of wetland ecosystems. However, monitoring of the restoration situation remains incomplete. In this study, we investigated the effects of wetland restoration on the macroinvertebrate taxonomic structure and feeding functional groups (FFGs) in the Naolihe National Nature Reserve (NNNR). Macroinvertebrate taxonomic diversity can be used to monitor wetlands, and we hypothesized that FFGs serve the same function. We calculated the diversity index, performed a non-metric multidimensional analysis based on macroinvertebrate taxonomics and FFGs, and subsequently, performed a t-test on the results. The results showed that macroinvertebrate diversity and FFGs analyses were in general agreement with taxonomic diversity, indicating that the macroinvertebrate community in the wetland with five years of fallow land was resembled that of the natural wetland. In contrast, the macroinvertebrate community in the wetland with two years of fallow differed significantly from that in the natural wetland. Additionally, the results of the ecosystem attributes based on biomass and FFGs showed that restored wetlands exhibited lower habitat stability than natural wetlands. Nutrients (NH4+-N, NO3−-N, and total phosphorus) explained the changes in macroinvertebrate FFGs in the restored wetlands to a greater extent than in the natural wetlands. The results of this study highlight the importance of macroinvertebrate FFGs in wetland monitoring, which supports the use of macroinvertebrate FFGs in the NNNR to monitor wetland restoration.

Breeding pairs with color aberrations in oriental reed warblers.

In 2017, one pair of Oriental reed warblers (Acrocephalus orientalis) with color aberrations was found in Yongnianwa National Wetland Park, Hebei, China. The female bird exhibited white feathers on the head, neck, and upper back, and the base of the beak was flesh-red in color. The male had a few feathers on the outer edges of the left and right primary wing coverts that were white, which was determined to be leucism after analysis. The breeding pairs laid their first egg on May 29, with a clutch size of four eggs. After an incubation period of 13 days, two chicks hatched on June 13, 2017. The nest was found empty on June 20 when the chicks were 7 days old and before fledging age; therefore, it was presumed that the chicks had been predated. A white parrot egg was added to the nest during the incubation period to test the egg recognition ability of breeding pairs and was successfully rejected. To the best of our knowledge, this is the first report of color aberrations in the Oriental reed warbler, and we found that this color aberrations did not affect some reproductive and antiparasitic behaviors of the birds, but whether it affects their breeding success needs to be further studied.

A hydrologic and land cover‐based habitat model for use in bog turtle (Glyptemys muhlenbergii) conservation

Abstract The endangered bog turtle (Glyptemys muhlenbergii) exemplifies issues related to rare species conservation; presence surveys have low detection and variables used in habitat models can lack relevance to established biological relationships of the species to its environment. The species' use of groundwater saturated soils and stream networks as core habitat and dispersal corridors has been documented. Less is known about the landscape factors that promote the formation and persistence of wetlands used for core habitat. A GIS‐based resource selection function was developed to predict bog turtle habitat use. Trained on 1 ha plots centred on occupied sites and pseudo‐absent plots constrained to areas within 56.4 m to stream network centrelines, the model tested the capacity of a topographic wetness index (TWI), stream order and soil, wetland and land cover type to predict the presence of suitable habitat and turtle occupancy. Landscape variables were sampled at 10 m resolution, but variable selection and model performance were analysed at 100 m resolution to maintain a biologically relevant 1 ha habitat scale and accommodate the resolution of other variables. Suitable habitat and turtle presence were best predicted by intermediate to high values of TWI, land cover with low vegetation height and wetlands, second‐ and third‐order streams and the occurrence of mapped National Wetland Inventory polygons and hydric soils. Very high values of TWI were negatively associated with habitat suitability. The area under the curve of the best model was 0.833. Suitable habitat was found on 88% of 55 independent sites selected using the model and nine new occupied sites were confirmed. Model error is discussed with consideration of human‐altered drainage networks on the agricultural landscape.

Influence of Land Use and Land Cover on the Quality of Surface Waters and Natural Wetlands in the Miranda River Watershed, Brazilian Pantanal

Water quality assessment stands as a fundamental step in water resource management. In addition to substances and organisms present in the water, land use and land cover are two factors also affecting water quality. This study analyzed the correlation and influence between water quality and land use and land cover in the Miranda River Basin (MRB) and the natural wetlands in the Pantanal Biome. Using a watershed-wide approach, results suggested that water quality management policies can be considered in terms of sub-basins (smaller planning units). The Water Quality Index (WQI) was considered GOOD or EXCELLENT throughout the MRB. It was observed that the natural wetlands have the capacity to contribute to improving the WQI, with reductions in thermotolerant coliforms and turbidity; however, high values were found for thermotolerant coliforms, a temporal increasing trend of biochemical oxygen demand (BOD), and a reduction in dissolved oxygen and total phosphorus. Conversely, in these flooded areas, trends of a decrease in dissolved oxygen and an increase in BOD levels were found. Natural wetlands play important hydrological and ecological roles in water quality, storing, removing, and cycling nutrients. They are highly relevant areas for defining watershed management and conservation strategies, environmental protection, and providing ecosystem services.

Groundwater seeps are hot spots of denitrification and N2O emissions in a restored wetland

Restorations of former cranberry farms (“bogs”) aim to re-establish native wetland vegetation, promote cold water habitat, and attenuate nitrogen (N) delivery to coastal waters. It is unclear, though, how elements of restoration design such as microtopography, groundwater interception, and plant communities affect N removal via denitrification. In a recently restored riparian cranberry bog with created microtopography, we compared denitrification potential, nitrous oxide (N2O) yield of denitrification (ratio of N2O:N2O + N2 gases), in situ N2O fluxes, soil chemistry, and plant communities at the highest and lowest elevations within 20 plots and at four side-channel groundwater seeps. Denitrification potential was > 2 × greater at low elevations, which had plant communities distinct from high elevations, and was positively correlated with plant species richness (Spearman’s rho = 0.43). Despite detecting high N2O yield (0.86 ± 0.16) from low elevation soils, we observed small N2O emissions in situ, suggesting minimal incomplete denitrification even in saturated depressions. Groundwater seeps had an order of magnitude higher denitrification potentials and 100–300 × greater soil NO3− concentrations than the typically saturated low elevation soils. Groundwater seeps also had high N2O yield (1.05 ± 0.15) and higher, but spatially variable, in situ N2O emissions. Our results indicate that N removal is concentrated where soils interact with NO3–rich groundwater, but other factors such as low soil carbon (C) also limit denitrification. Designing restoration features to increase groundwater residence time, particularly in low lying, species rich areas, may promote more N attenuation in restored cranberry bogs and other herbaceous riparian wetlands.

Eco-Engineering Improves Water Quality and Mediates Plankton–Nutrient Interactions in a Restored Wetland

Eco-engineering is an important tool for wetland restoration, but there are still large theoretical and application gaps in the knowledge of the effects of eco-engineering implementation on the interactions between environmental conditions and organisms during wetland restoration processes. In this study, we investigated water quality parameters and plankton communities in a national wetland park to clarify the mechanism of changes in plankton community structure and their ecological networks before and after the eco-engineering project. Undoubtedly, we found water quality was significantly improved with increased metazooplankton diversity after the implementation of eco-engineering. Ecological engineering reduced the effect of farmland drainage on the restored wetland and changed the phytoplankton community structure, which significantly reduced the relative abundance of Cyanobacteria and increased the relative abundance of Bacillariophyta. The structural equation modeling revealed that the total effect of metazooplankton on phytoplankton was significantly enhanced and associated with weakened relationships between phytoplankton and environmental variables after eco-engineering. In addition, the ecological network analysis also showed that the network connection between phytoplankton and metazooplankton was stronger after the eco-engineering implementation, leading to an enhanced biotic interactions in different trophic levels. These results indicate that the main approach to regulating primary producers in wetland ecosystems changed from “bottom-up” control to a combination of “bottom-up” and “top-down” control under the intervention of artificial recovery measures. Our findings shed new light on the effects of eco-engineering on the interactions between water quality and organisms and provide a scientific basis for the sustainable management of wetland ecosystems.

Soil water content and RubisCO activity control the carbon storage in soil under different land uses in Sanjiang Plain, China

Soil carbon storage plays a crucial role in mitigating the climate warming and is significantly impacted by the land use pattern. To better understand soil carbon stability and the underlying microbial mechanism, based on qPCR, ELISA, and fluorescence techniques, the effects of land use changes on soil microbial abundance, enzyme activity, and soil carbon storage were investigated in the complex ecosystems of cropland, forestland, and wetland along three typical river (Wolvlan river, Bielahong river, Wusuli river) basin in Sanjiang Plain, China. We hypothesised that croplands soil carbon storage is lower than forestlands and wetlands, which is regulated by soil water content, microbe and enzyme activity. Results showed that topsoil TC in wetlands (85.54 mg·g−1) was higher than those in croplands (33.46 mg·g−1) and forestlands (46.13 mg·g−1). Topsoil water content increased 73.90 % and 71.64 % in wetlands than in farmland and forestlands, respectively. Additionally, reclamation diminished topsoil carbon storage. In croplands, soil dissolved organic carbon, microbial biomass carbon, microbial biomass nitrogen, available nitrogen, bacterial abundance, and soil enzymes (i.e., RubisCO, β-glucosidase, cellobiohydrolase, 1,4-N-acetylglucosaminidase and acid phosphatase) activities were substantially lower than those in wetlands. Structural equation modeling showed that soil carbon storage was positively related to soil water content and RubisCO activity but negatively related to soil bacterial abundance. Soil water content had the largest standardised total positive effect coefficient and indirectly influenced soil carbon storage by affecting RubisCO activity. Soil depth had a greater effect on SMC, hydrolase and site had a greater effect on bacteria and fungi abundance. The results highlight that the alteration of carbon fixing enzyme activity by soil water content is a crucial mechanism for soil carbon sequestration in response to land-use change. Management strategies that conserve natural wetlands, increase soil water content and minimize land disturbance would be effective in maintaining soil carbon stocks.

Spatio-temporal variations and influencing factors analysis of coastal wetlands in Tianjin, China

Coastal wetlands are one of the world’s most threatened ecosystems and the influences of climate change and anthropogenic factors on changes in coastal wetland distribution have been the subject of active research in recent years. However, the multi-year intergenerational trends in coastal wetland areas, and the factors influencing them in China have not been fully studied using geographic spatial data during the past 30 years. The relative contributions of climate change and anthropogenic factors to spatio-temporal variations in coastal wetland area also remain to be described. In this study, we discuss changes in the coastal wetland areas and the reasons behind them in Tianjin, which is one of China’s fastest developing regions, using remote sensing and geographic information system technology, Pearson correlation analysis, the relative weight method and the land expansion extraction module, the land expansion analysis strategy (LEAS) model of the Patch-generated Land Use Simulation (PLUS) model. The results showed that the total wetland area declined from 2233.59 km2 in 1984 to 1742.73 km2 in 2020. We conclude that the expansion of non-wetland land types is the main driver of natural wetland area decrease, with 830.86 km2 of natural wetlands having been converted to non-wetlands during this period. The large areas of shallow water and tidal marsh that have been converted to construction and bare land particularly emphasize the primary importance of urbanization and coastal reclamation in driving wetland reduction. The results showed that the temporal variation of natural wetlands area was correlated with population density (PD), total gross domestic product (GDP), annual mean temperature (AMT), average relative humidity (ARH), and primary (PI), secondary (SI), and tertiary industrial development (TI). PD, PI, TI, GDP, SI, AMT, and ARH contributed to 24.47 %, 18.21 %, 15.74 %, 14.16 %, 12.77 %, 7.09 %, and 4.86 % of the wetland area decrease, respectively. PD, distance to settlements (DS), distance to railways (DRW), AMT, distance to rivers (DR), and GDP contributed 17.61 %, 14.27 %, 13.83 %, 13.62 %, 12.07 %, and 10.92 % of the spatial variations of natural wetland area, respectively, which showing the predominant effects of anthropogenic variables on the spatio-temporal natural wetland areas. Our results are valuable in identifying the dynamic spatio-temporal variations in coastal wetlands to improve our understanding of the impacts of climate change and human activities on coastal wetlands to help in the future protection and restoration of wetlands.

Harnessing Lignocellulosic Waste‐Derived Carbon Materials for Green Electrochemical Applications

AbstractPhytoremediation and constructed wetlands are widely employed processes for the decontamination of soils and waters. These sustainable, effective, and cost‐efficient technologies rely solely on the use of plants. However, the application of these processes results in the accumulation of lignocellulosic residues, like it occurs with natural wetlands, which present a significant challenge due to the potential entry into the food chain of the adsorbed pollutants or the risk of initiating uncontrolled fires due to the accumulation of dead biomass. Nevertheless, rather than being perceived as a drawback, this can be seen as a potential source of materials. Carbonaceous materials are gaining increasing significance in the field of electrochemistry, normally improving their features through some type of thermal treatment. In this study, different types of thermal treatments applied to lignocellulosic wastes are reviewed pointing out pyrolysis and hydrothermal carbonization (HTC). Additionally, four environmental and energy electrochemical applications where this type of waste has been used as precursors of electrode materials are briefly examined: energy storage (supercapacitors, Li−Na‐ion batteries), hydrogen production (H2), microbial fuel cells (MFCs) and hydrogen peroxide (H2O2) production. Recent research findings, as discussed throughout this review, suggest a promising future for the utilization of lignocellulosic waste in electrochemical applications.

SATELLITE MONITORING OF DRAGOMAN MARSH FOR THE PERIOD 2018-2023

In this study, monitoring of the Dragoman Marsh was conducted for the period 2018-2023. The Dragoman Marsh is distinguished as the largest natural karst wetland area in Bulgaria. Monitoring of this natural formation is essential for studying its dynamic processes and ensuring its protection. The use of satellite data represents a key tool in this context. The data from the Sentinel 2 satellite being utilized for this purpose. Following appropriate processing of this data, classification of the object by years and seasons - spring and summer-autumn - was performed, using indices such as NDVI, NDWI, and TCT based index - NDGI. The obtained results contribute to a better understanding of the development of the wetland area and provide guidance for its conservation and management.