Wetland Health Research Articles

Great Salt Lake wetland vegetation and what it tells us about environmental gradients, drought, and disturbance

Great Salt Lake (GSL) wetlands support more than 300 species of migratory birds and provide many ecosystem functions, including flood and drought attenuation, dust mitigation, and water quality improvement. Wetland vegetation is a key factor in providing those services and can also tell us about how healthy a wetland is. From 2103 to 2022, 135 GSL wetlands were surveyed to develop a multi-metric index of GSL wetland condition. That wetland condition data, along with environmental variables like soil and water chemistry and physical disturbance, are summarized here as 1) an ecological characterization of the three main types of GSL wetlands, 2) a description of how the plant community differs across environmental and anthropogenic disturbance gradients, and 3) assessment of the major risks to GSL wetland health. GSL wetland plant species are generally resistant to environmental disturbance because of the anatomical and physical adaptations that allow them to survive in dynamic wetland environments. However, land use conversion and the rapid expansion of invasive species, the major threats to GSL wetland health, have seriously degraded wetland condition around GSL. In addition to being useful in wetland monitoring and assessment, the results presented here can also identify wetlands in need of enhanced protection or those with restoration potential as well as setting realistic wetland restoration goals for the region.

A three-class carbon pool system for normalizing carbon mapping and accounting in coastal areas

Climate change is a key issue receiving increasing global attention. Coastal areas play an important role in mitigating climate change because of enormous potentials for carbon sequestration. Simulating and evaluating the carbon storage, increment, and value of coastal areas is of considerable importance in achieving carbon neutrality. In this study, the South Coast of Hangzhou Bay in China was selected as the study area. A three-class carbon pool system was established based on vegetation and soil and considering the coastline as the boundary for comprehensively revealing the carbon sink in coastal areas and accurately distinguishing the roles of different carbon pools. Then, the maps of carbon storage and increment were generated by integrating the field and remote sensing data through “from point to area” spatial simulations. An accounting list was developed for systematically summarizing, precisely quantifying, and visually displaying the carbon storage, increment, and value following the three-class carbon pools. Results indicated that the carbon sink showed a gradient change from sea to land. Salt marshes had low storage but high increment, whereas areas above the coastline had the opposite characteristics. The total carbon storage of vegetation and soil were 1417.94 Gg and 3359.07 Gg, respectively, and their carbon increments during 2011–2022 were 309.17 Gg/yr and 29.46 Gg/yr, respectively. The carbon storage per area of vegetation and soil were 27.66 Mg/ha and 53.09 Mg/ha, respectively, and their carbon increments during 2011–2022 were 6.03 Mg/(ha yr) and 0.47 Mg/(ha yr), respectively. As the main body of blue carbon, salt marshes have achieved distinctly higher increment than the adjacent areas above the coastline. The carbon increment per area of soil was lower than 1/5 of vegetation in salt marshes. Mudflats had low carbon increment but large storage because of the extensive area. Alien species had higher increment in terms of vegetation but similar one from the perspective of soil compared with native species, denoting the low decrease of soil carbon sink when eliminating alien species. Considering the hazard of alien species to the health of coastal wetlands, this indicates the feasibility and necessity to develop the high-quality carbon sink in the study area. The carbon sink value based on the carbon stored in the soil summed to 1.68 million yuan, and were increased by 33%, 7%, 48%, and 45% in scenarios of baseline scenario, economic development, ecological protection, and comprehensive optimization, respectively. The present study validated the high carbon increment and immense increase potential and provided an applicable system to normalize carbon mapping and accounting in coastal areas.

The Impact of Anthropogenic Pollution on Tidal Water Quality in Mangrove Wetlands

Mangrove wetlands are vulnerable coastal ecosystems that provide critical habitats for aquatic life. Tai O is a popular tourist village on Lantau Island, Hong Kong, which is surrounded by mangrove wetlands with rich biodiversity; and this village is also famous for its traditional stilt houses. However, the untreated municipal sewage from some stilt houses is directly discharged into nearby tidal channels, potentially threatening health of the adjacent mangrove wetlands. In order to evaluate the anthropogenic impact on these wetlands and identify the potential sources of their pollution, this study aimed to evaluate spatial (at the sampling points) and temporal (during weekdays and weekends) differences in the quality of their tidal water, and examine relationships between the water quality and the density of the stilt houses. The results indicated that the water quality was worse during weekends. The ammonia concentrations in most samples exceeded the limits of the Hong Kong Water Quality Objectives, China’s Sea Water Quality Standards, and even the U.S. EPA criterion for fish reproduction. This high ammonia input could potentially adversely affect the mangrove ecosystem, underscoring the need for further comprehensive studies. Moreover, some of the weekend water samples had lower dissolved oxygen levels and were polluted by phosphate. Our Principal Component Analysis revealed that water quality was correlated with stilt house density, suggesting that anthropogenic inputs of untreated sewage was the major source of pollution. These findings highlight that nutrients released from human activities, particularly ammonia and phosphate, must be controlled for a better protection of mangrove wetland ecosystems.

The environmental risk assessment of constructed wetlands filled with iron and manganese ores in typical antibiotic treatment

Constructed wetlands (CWs) is considered as an efficient and environmentally friendly technology for advanced wastewater treatment to eliminate organic pollutants such as sulfamethoxazole (SMX) and trimethoprim (TMP). Iron (Fe) and manganese (Mn) ores have attracted more and more attention as CWs substrates in treating SMX and TMP, but the potentially negative environmental effects of wetland effluents, ore contaminants leached from the substrates and the risk of transmission of antibiotic resistance genes (ARGs) are still not clear. Three CW groups with different substrates (river sand (C-CW), Fe ore (Fe-CW), and Mn ore (Mn-CW)) were set up to evaluate the average removal rates and environmental risk in treating wastewater containing SMX and TMP. The results showed that the average removal rates of SMX and TMP by Fe-CW and Mn-CW were significantly higher than that of C-CW by 12.46%, 6.59% and 38.93%,15.39% respectively (p < 0.05), suggesting that both Fe and Mn ores facilitated the removal of antibiotics. However, the least abundance of ARGs was found in the layer of Fe ore at the middle layer (ML) in Fe-CW among all CWs, which suggested that Fe ore could reduce the risk of ARGs transmission. Although the environmental risk of Fe-CW and Mn-CW effluent was low, Fe-CW effluent inhibited the growth of Chlorella in both 48h and 72h experiments, while Mn-CW effluent showed an inhibitory effect in 48h and then promoted the growth in 72h. Meanwhile, these findings offer valuable insights for wetland health assessment and substrate selection for CWs.

Using Normalize Difference Vegetation Index to Infer Wetlands Salinity and Organic Contribution to Vertical Accretion Rates

AbstractVegetation is a key component controlling soil accretion in coastal wetlands through production of belowground organic matter and enhanced deposition of mineral sediments. Vegetation structure is a proxy for wetland health and degradation that can be monitored at large scales with remote sensing. Among different multispectral indices, the Normalized Difference Vegetation Index (NDVI) is generally used for this purpose. Using Google Earth Engine (GEE), NDVI time‐series are extracted around 45 monitoring stations of the Coastwide Reference Monitoring System (CRMS) located in Terrebonne Bay, Louisiana, USA. NDVI tends to increase from saline to freshwater wetlands. Using these NDVI observations and in situ measurements of salinity, soil accretion rates, and geomorphic metrics (i.e., elevation, distance from the bay or from the nearest channel bank), empirical models were developed to derive maps of organic mass accumulation rates and salinity. The analysis shows that NDVI can be used to reproduce the salinity gradient in Terrebonne Bay, as the index captures differences in vegetation cover, which depend on salinity. A negative relationship between NDVI and organic accumulation mass rates is also found, indicating that saline marshes tend to accumulate more organic material compared to fresh wetlands.

Assessment of Community Dependence and Perceptions of Wetlands in the Upper Chindwin Basin, Myanmar

Understanding the relationship between communities and wetland ecosystems is imperative to facilitate the development of wetland management and conservation strategies that can effectively safeguard wetland health and sustain the flow of ecosystem services. To understand the knowledge, attitude, and perception of communities on wetland ecosystem services, a survey was conducted involving 133 households from 4 villages dependent on 5 wetlands within the Upper Chindwin Basin (UCB), northwestern Myanmar. Most of the respondents extracted wetland resources for subsistence and income. A total of 84% of the households depended on wetland fish for their primary protein consumption, while 70% (n = 94) collected fuelwood from wetlands for subsistence. The survey participants unanimously recognized the benefits of wetland ecosystem services (i.e., provisioning benefits), particularly for fish, food, fiber, fuel, natural medicines, ornamental resources, and minerals. A total of 97% of the participants lacked knowledge of any existing law or regulation that ensures wetland protection in Myanmar. Furthermore, 87% of the respondents concurred that the government has not adequately endeavored to promote awareness of wetland conservation in this remote area due to lack of capacity and resources. This study establishes a baseline for the region and recommends designing and implementing a community-centric wetland action plan. This action plan provides a self-sustaining and cost-effective approach to conserve wetlands and is crucial in enhancing the capacity of dependent communities to participate and eventually lead wetland management of UCB.

The relationship between mountain wetland health and water quality: A case study of the upper Hanjiang River Basin, China

This study investigates the degradation process of mountain wetlands in the upper Hanjiang River Basin (HRB) over a 30-year span from 1990 to 2020. In particular, the landscape development intensity (LDI) index was employed to conduct a comprehensive assessment of the wetland health. This was subsequently combined with the spatio-temporal changes of water quality in the basin to explore the potential correlations between the health status of mountain wetlands and the associated watershed water quality. The results show that over the past three decades, wetland ecosystems have shrunk by 18% due to conversion into farmland, grass, construction land and forest land. This was significant between 2010 and 2020, as shown by a land use dynamic index of −1.121% during 2010–2020, which was significantly higher than that in the preceding two decades (0.003%, 0.367%) (p < 0.05). LDI values for individual sub-watersheds across different years ranged from 2.39 to 4.93, demonstrating an increasing trend since 2010. This indicates a heightened level of human interference in mountain wetlands. Although the water quality within the basin generally adhered to the Class II surface water quality standard, total nitrogen (TN) (primarily from farming) was a concern. Areas with relatively more human activity were observed to exhibit increased pollution levels, as demonstrated by a positive correlation between LDI and the concentrations of total phosphorus (TP), ammonium nitrogen (NH4+-N), and chemical oxygen demand (COD) in the basin. The LDI of the mountain wetland exhibited a consistent positive correlation with the water quality comprehensive function, both during the flood (r = 0.77–0.81) and non-flood (r = 0.61–0.70) seasons (p < 0.05). This indicates the significant impact of the wetland landscape structure on the water quality within a 1000 m radius on either side of the river. Special attention should be paid to the management and allocation of wetland landscapes within this 1000 m buffer zone. Furthermore, efforts to control upstream pollutant emission should be strengthened.

Impact of Artisanal Gold Mining on Wetland Health in Buhweju District, Southwestern Uganda

Wetland degradation due to anthropogenic activities including artisanal gold mining is widely common in Uganda, and this affects vegetation health status if not controlled. However, the use of the Normalised Difference Vegetation Index (NDVI) to determine the health status of wetlands is rare. In this study, remote sensing techniques with the use of spatial-temporal Normalised Difference Vegetation Index (NDVI) were used for the wetlands in Bitsya Subcounty, Buhweju district (noted for artisanal gold mining with the use of mercury) to determine the wetland health status for the period between 2012-2021. This was for the purposes of identifying target areas for intervention and developing appropriate, location-specific intervention options. 7 images of 30 * 30 m and 3 images of 10 * 10 m respectively, ortho-rectified, cloud-free Landsat and Sentinel images obtained from the USGS archive were analysed. The results showed that the high NDVI value (0.775) was detected in the year 2019 and the low NDVI value (0.068) was detected in the year 2017. The NDVI maps showed low values mostly in the middle of the wetland where artisanal gold mining was mostly taking place, indicating a huge decline in the wetland health status as compared to other wetland edges noticed with high NDVI. The results from the study suggest that the wetland policies in the study area could not be effectively implemented and this reduces the vegetation health status, threatening the functionality of the wetland and as well as loss of the free natural goods and services derived from them. This necessitates the development of wetland restoration campaigns. However, failure to implement the wetland policies may have an ecosystem impact on the wetland micro and macro-organisms, soil nutrients, and water quality as well as a decline in vegetation health

A Comprehensive Multi-Metric Index for Health Assessment of the Poyang Lake Wetland

The Poyang Lake wetland is home to many unique and threatened species. However, it has been severely degraded in recent decades due to the joint effects of human influence and climate change. Here we establish a wetland health index (WHI) for Poyang Lake, which considers five types of attributes (biological, water quality, sediment, land use and remote sensing, and socio-economic attributes) of the wetland to evaluate wetland conditions. Forty-nine variables across five categories were assembled as candidate metrics for the WHI through field surveys conducted in 2019 at 30 sample sites. Principal component analyses were performed to identify the most important variables in each of the five categories as the primary metrics of each index category (e.g., biological index). Eighteen variables were finally selected from the five categories to construct the WHI. The WHI scores varied from 0.34 to 0.80 at the 30 sample sites, with a mean of 0.55. The Poyang Lake wetland is generally in fair condition according to our WHI scores. Sample sites where connected rivers flow into the lake were assessed to be in a poor condition, highlighting the importance of reducing pollution input from rivers for wetland conservation. Scores of individual indices of the five categories were not highly correlated (0.29 ≤ pairwise Spearman’s r ≤ 0.69), suggesting that information provided by each index is different and might be complementary. The composite WHI as well as the individual category indices can provide comprehensive information on wetland conditions that would facilitate the development of more targeted and effective strategies for wetland management.

The Impact of Restoration and Protection Based on Sustainable Development Goals on Urban Wetland Health: A Case of Yinchuan Plain Urban Wetland Ecosystem, Ningxia, China

Drawing heavily upon the Sustainable Development Goals (SDGs), an SDG–pressure–state–response (PSR)–ecological–economic–social (EES) model and an index system for wetland ecosystem health assessment were constructed from the three dimensions of environment, economy, and society. By using the Yinchuan Plain urban wetlands in the Yellow River Basin of China as a case study, their ecological health status from 2000 to 2020 was systematically evaluated by integrating information from remote sensing technology, geographic information technology, field sampling, information entropy (IE), a landscape index, and a Comprehensive Evaluation Index. The results show that the restoration and protection of wetland ecosystems have achieved remarkable results in the Yinchuan Plain. The wetland ecological health index has significantly increased from 0.26 to 0.67, which is an increase of 157.7%, and the health level increased from poor (II) to sub-healthy (IV). Factors restricting the healthy development of wetland ecology in the Yinchuan Plain include wetland construction, investment, population density, the number of tourists, and fertilizer use. The research results show that the wetland restoration and protection have achieved specific environmental, economic, and social results in the Yinchuan Plain. However, we also need to pay attention to increasing the investment in wetland environmental governance, strictly controlling the intensity of land use and the total amount of chemical fertilizer applied in various regions, scientifically carrying out wetland restoration and protection, reasonably coordinating the relationship between environment and society, and providing technical and decision-making support for wetland management and protection. This study provides a reference for the ecological governance and sustainable development of wetlands in large river basins worldwide.

Effectiveness of rapid sampling assessments for wetland-breeding amphibians

A primary response to the Clean Water Act has been the development of numerous indices of biotic integrity (IBI) using various taxonomic groups to assess the condition of water bodies in the United States. The IBI is a frequently used approach for assessing the ecological integrity of streams; however, it is less commonly applied to wetland systems, despite the scientific and policy needs to assess wetland condition and develop ecological performance goals for wetland monitoring, creation, and restoration. Although a great deal of attention has been given to wetland acreage due to the “no net loss” policy over the past two decades, much less attention has been given to the ecological integrity of these same wetlands. To assess wetland health and function, regulatory agencies and land managers need clear performance standards that are based on the ecology of wetland organisms. To address this need, we sampled 242 wetlands distributed across 45 managed properties in Illinois, U.S.A. over three years (2012–2014) for adult and larval amphibians (12 samples per wetland). Amphibian assemblages make up critical ecological components of many wetland ecosystems and are considered useful bioindicators of environmental change because they are sensitive to various forms of environmental and habitat alteration. We developed an amphibian-based IBI (hereafter aIBI) for the assessment of seasonal wetlands and optimal sampling strategies to best quantify these wetlands (i.e., assessment of time and effort). The aIBI applied a conservation coefficient to all species captured; conservation coefficients were developed through a survey of amphibian experts (n = 16). We captured 25 amphibian species with an average of 7.11 amphibian species (range 1–13) per site. Using the species occurrence data collected from both dipnet and minnow trap surveys over 12 survey periods, we assessed the average percent error in the estimation of aIBIs and species richness. Our results show that a wetland can be accurately evaluated with amphibians in one field season, but that multiple samples during that field season will be necessary. We show that 4–5 surveys using multiple methods distributed throughout the spring and summer are required. This level of effort may be incongruent with existing definitions of ‘rapid assessment’, but it is the necessary level of effort needed to confidently and accurately evaluate wetlands using amphibians as an indicator taxon. Additionally, aIBI provides a more robust framework to assess wetland integrity compared to simple species richness or other similar methodologies.

Application of pressure–state–response approach for developing criteria and indicators of ecological health assessment of wetlands: a multi-temporal study in Ichhamati floodplains, India

BackgroundTropical floodplain wetlands are among the most disturbed and intensively harvested ecosystems. Their sustainable management is often hindered due to the lack of comprehensive, coherent, and standardized assessment frameworks of wetland ecological health (WEH). In this study, a set of appropriate criteria and indicators (C&I) of WEH assessment was developed and tested on seven wetlands of River Ichhamati, eastern India.MethodsBased on the pressure–state–response (PSR) approach, evaluation indicators representing ecological, socio-economic, and institutional sustainability issues of floodplain wetland systems were either selected or formulated through literature survey and stakeholder consensus. Weights of indicators were assigned by the entropy weighting method and then used in the Technique for Order of Preference by Similarity to Ideal Solution model to determine the Euclidean distances of each wetland from the positive ideal solution and negative ideal solution. Subsequently, a comprehensive wetland ecological health index (CWEHI) was constructed from these distances to portray the condition of any PSR system component in a wetland under a fivefold classification scheme, namely ‘excellent health’ (CWEHI ≥ 0.81), ‘good health’ (0.61–0.80), ‘moderate health’ (0.41–0.60), ‘weak health’ (0.21–0.40), and ‘morbid’ (≤ 0.20).ResultsThe developed C&I set contains 8 criteria and 38 indicators under pressure component, 7 criteria and 49 indicators under state component, as well as 4 criteria and 18 indicators under response component. When applied in 2016 and 2022, it was found that the Panchita and Aromdanga wetlands were continuously in weak and morbid health status, while the Madhabpur wetland always showed an excellent or good status for all components. Health of other wetlands oscillated between moderate and morbid health across assessment years and system components.ConclusionsThe developed C&I set was found to be a flexible, holistic, and refined framework that could be applied elsewhere in similar assessments with minor indicator-level adjustments. The present assessment inferred that agriculture-dominated wetlands were more affected by amplified environmental pressure than fishing-dominated wetlands. Absence of persistent water flow from main river channel, wide-spread jute-retting, agriculture-induced eutrophication, proliferation of aquatic weeds were identified as the major causes of rapid ecological deterioration.

Aboveground biomass estimation of wetland vegetation at the species level using unoccupied aerial vehicle RGB imagery.

Wetland vegetation biomass is an essential indicator of wetland health, and its estimation has become an active area of research. Zizania latifolia (Z. latifolia) is the dominant species of emergent vegetation in Honghu Wetland, and monitoring its aboveground biomass (AGB) can provide a scientific basis for the protection and restoration of this and other wetlands along the Yangtze River. This study aimed to develop a method for the AGB estimation of Z. latifolia in Honghu Wetland using high-resolution RGB imagery acquired from an unoccupied aerial vehicle (UAV). The spatial distribution of Z. latifolia was first extracted through an object-based classification method using the field survey data and UAV RGB imagery. Linear, quadratic, exponential and back propagation neural network (BPNN) models were constructed based on 17 vegetation indices calculated from RGB images to invert the AGB. The results showed that: (1) The visible vegetation indices were significantly correlated with the AGB of Z. latifolia. The absolute value of the correlation coefficient between the AGB and CIVE was 0.87, followed by ExG (0.866) and COM2 (0.837). (2) Among the linear, quadratic, and exponential models, the quadric model based on CIVE had the highest inversion accuracy, with a validation R2 of 0.37, RMSE and MAE of 853.76 g/m2 and 671.28 g/m2, respectively. (3) The BPNN model constructed with eight factors correlated with the AGB had the best inversion effect, with a validation R2 of 0.68, RMSE and MAE of 732.88 g/m2 and 583.18 g/m2, respectively. ​Compared to the quadratic model constructed by CIVE, the BPNN model achieved better results, with a reduction of 120.88 g/m2 in RMSE and 88.10 g/m2 in MAE. This study indicates that using UAV-based RGB images and the BPNN model provides an effective and accurate technique for the AGB estimation of dominant wetland species, making it possible to efficiently and dynamically monitor wetland vegetation cost-effectively.

Ecosystem health assessment and comparison of natural and constructed wetlands in the arid zone of northwest China

Wetlands in the arid zone of northwest China have ecological values such as climate regulation, water conservation, and biodiversity maintenance. However, in the context of global warming and economic development, the degree of natural and human interference in the wetlands has been increasing, and wetland health problems are becoming increasingly severe. The current comparative research on the ecosystem health evaluation of natural and constructed wetlands and their sustainable development in the arid zone of northwest China is not perfect, so we selected the natural (Dunhuang Xihu Wetland) and constructed wetlands (Suzhou District Wetland) as research objects. The ecosystem health evaluation system has been developed from 5 levels of the drive, pressure, state, impact, and response (DPSIR). The ecological health status and impact factors were evaluated for the two wetlands using socioeconomic data combined with remote sensing technology from 2000 to 2019. The results showed that 1) the ecological health of natural and constructed wetlands was in a medium healthy state, and the ecological health values of the wetlands showed a trend of decreasing and then increasing from 2000 to 2019, with 2005 as the turning point. The ecological health status of natural wetlands (0.46) was better than that of constructed wetlands (0.42). 2) The main reasons for the degradation of constructed wetlands (-3.20%) were the urban population expansion and blind agricultural reclamation of wetlands, while the degradation of natural wetlands (-6.45%) was dominated by extreme climatic conditions and overuse of water resources. These results provide case support and a theoretical basis for the conservation management and sustainable development of wetland ecosystems in the arid zone.

Occurrence, source identification and ecological risk assessment of heavy metals in water and sediments of Uchalli lake – Ramsar site, Pakistan

Uchalli Lake is an internationally significant Ramsar site that needs protection for supporting migratory birds. The current study aimed to assess wetland health by examining water and sediments utilizing total and labile heavy metals concentration, pollution indices, ecological risk assessment, water recharge and pollution induction sources through isotope tracer techniques. Al concentration in water was of serious concern as it was 440 times higher than the maximum acceptable concentration of Environmental Quality Standard of the UK for aquatic life in saline waters. Labile concentration predicted very severe enrichment of Cd, Pb, and moderate enrichment of Cu. Modified ecological risk index predicted very high ecological risk in sediments. The δ 18O, δ2H and D-excess values indicate that the lake was mainly recharged by local meteoric water. Enriched values of δ 18O and δ2H suggest a high evaporation of lake water, making lake sediments more enriched with metals. Isotopic and D-excess values of groundwater suggest a quick rainwater recharge to groundwater around the Uchalli Lake. Nitrates isotopes indicate that the rainwater runoff is main source of induction of fertilizers, pesticides and soil bonded metals in the lake system. The lake is recharged by rainwater runoff, from catchment areas, that erode the soil particles and agricultural residual waste dumped in the lake.

Assessing the Landscape Ecological Health (LEH) of Wetlands: Research Content and Evaluation Methods (2000–2022)

Wetlands are often referred to as the Earth’s kidneys. However, wetlands worldwide are still negatively affected due to a lack of comprehensive understanding of wetland landscape ecological health (WLEH). Based on this background, we analyzed and compared the conceptual definitions, research progress, contents (in terms of structural, functional, and process health), and methods (indicator species approach, ecological integrity assessment, conceptual model evaluation including the vigor–organization–resilience (VOR), pressure–state–response (PSR), and ecological feature–function–socioeconomic (EFFS) models, and water–gas CO2 calculation) over the past 20 years (2000–2022). Moreover, the concept definition and research progress of ecosystem health (EH) and landscape ecological health (LEH) and WLEH research outlook were analyzed. In this study, it was shown that WLEH could be considered a LEH subset, while the LEH is a specific EH perspective. These three concepts share a common focus on ecosystem conditions, functions, and services while considering ecological processes and habitat characteristics. However, they differ in the scope and specific types of ecosystems considered. This review may provide references for ecological conservation and restoration of artificial and restored wetland landscapes.

Unveiling the Value of Nature: A Comprehensive Analysis of the Ecosystem Services and Ecological Compensation in Wuhan City’s Urban Lake Wetlands

Urban lake wetlands play an essential role in providing ecological services, promoting urban sustainability, and enhancing the quality of urban life. This study quantitatively assesses the ecosystem services value (ESV) of the Zhangdu, East, and Ziyang urban lake wetlands in Wuhan, China, based on primary survey data and methodologies, including the market price, shadow engineering, and travel cost methods. The ESV is categorized into direct use value (DUV), indirect use value (IUV), and non-use value (NUV). Our findings reveal that the non-use value proportion is significant, amounting to 1.569 × 108 CNY × yr−1 for Zhangdu Lake, 1.527 × 108 CNY × yr−1 for East Lake, and 1.060 × 108 CNY × yr−1 for Ziyang Lake. This indicates a high willingness to pay among respondents, reflecting a recognition of the value of wetland services. In addition to the non-use value, this study underscores the considerable material production, water conservation, and leisure tourism value that these urban lake wetlands provide. The assessment of ESV delivers a scientific basis for the management and protection of urban lake wetlands. It also highlights the challenges faced, such as pollution and fragmented management approaches due to unclear property rights and insufficient funding. This study concludes by emphasizing the need for future research to explore mechanisms that promote social participation in wetland management, with the aim of enhancing the overall ecological health of urban lake wetlands.

Effects of Long-Term (17 Years) Nitrogen Input on Soil Bacterial Community in Sanjiang Plain: The Largest Marsh Wetland in China.

Increased nitrogen (N) input from natural factors and human activities may negatively impact the health of marsh wetlands. However, the understanding of how exogenous N affects the ecosystem remains limited. We selected the soil bacterial community as the index of ecosystem health and performed a long-term N input experiment, including four N levels of 0, 6, 12, and 24 gN·m-2·a-1 (denoted as CK, C1, C2, and C3, respectively). The results showed that a high-level N (24 gN·m-2·a-1) input could significantly reduce the Chao index and ACE index for the bacterial community and inhibit some dominant microorganisms. The RDA results indicated that TN and NH4+ were the critical factors influencing the soil microbial community under the long-term N input. Moreover, the long-term N input was found to significantly reduce the abundance of Azospirillum and Desulfovibrio, which were typical N-fixing microorganisms. Conversely, the long-term N input was found to significantly increase the abundance of Nitrosospira and Clostridium_sensu_stricto_1, which were typical nitrifying and denitrifying microorganisms. Increased soil N content has been suggested to inhibit the N fixation function of the wetland and exert a positive effect on the processes of nitrification and denitrification in the wetland ecosystem. Our research can be used to improve strategies to protect wetland health.

A sustainable solution to manage ecosystem health of wetlands in urban and peri-urban areas of Lucknow district, India using geospatial techniques and community based pragmatic approach

Wetlands are multi-functional landscapes between terrestrial and aquatic ecosystems that provide habitat for wildlife, support groundwater recharge, moderate climate, control flood and fulfil the livelihood of the communities. Rapid population growth, urban expansion, and industrialization have caused the degradation of wetlands over the last few decades. The wetlands located in the urban and peri-urban areas are generally the most threatened ecosystems globally. The present study assessed the ecosystem health of urban and peri-urban wetlands of Lucknow district in India and recommended a sustainable solution for their management. Remote sensing data derived from the normalized difference vegetation index, modified normalized difference water index, and land use/land cover change were utilized for analyzing the spatiotemporal change in areas under wetlands, from 1989 to 2018. Site-specific indicators on pressure, state and response were integrated in FRAGSTATS-based assessment to construct a Pressure-State-Response (PSR) model. A qualitative field survey has been conducted through focus group discussion and expert opinion to validate the result from the PSR model. The results revealed that the overall health of the wetlands has deteriorated drastically in these peri-urban areas owing to anthropogenic activities. The wetland ecosystem's health is significantly correlated with land transformation. The study recommended community participation, and involvement of local authorities in storing rainwater, constructing culverts and channels, and interlinking them with wetlands for sustainable conservation and effective management of the wetland ecosystem.

A novel GIS-based multicriteria analysis approach for ascertaining the catchment-scale degradation of a Himalayan wetland

Wetland degradation through a diverse spectrum of anthropogenic stressors worldwide has taken a heavy toll on the health of wetlands. This study examined the health of a semi-urban wetland Bodsar, located in the Kashmir Himalaya using multicriteria analysis approach assimilating data on land use land cover (LULC), landscape fragmentation, soil loss, and demography. Wetland and catchment-scale land system changes from 1980 to 2022 were assessed using high-resolution imagery. Fragmentation of the natural landscape was assessed using the Landscape Fragmentation Tool (LFT) and soil loss was assessed using the Revised Universal Soil Loss Equation (RUSLE). In addition, the water quality was examined at 12 sites distributed across the wetland using standard methods. Satellite data revealed 12 categories of land use with areas under exposed rock, orchards, built-up and sparse forest having increased by 1005%, 623%, 274%, and 37% respectively. LFT indicated that the core (>500 acres) and core (<250 acres) zones decreased by approximately 16% and 64%, respectively, whereas the areas under the perforated, edge and patch classes increased significantly. RUSLE estimates show a ∼77% increase in soil erosion from 116.26 Mg a−1 in 1980 to 205.68 Mg a−1 in 2022, mostly due to changes in LULC. Total phosphorus (0.195–2.04 mg L −1), nitrate nitrogen (0.306–2.79 mg L −1), and total dissolved solids (543–774 mg L−1) indicated nutrient enrichment of the wetland influenced by anthropogenically-driven land system changes. The wetland degradation index revealed that 21% of the wetland experienced high-to-severe degradation, 62% experienced moderate degradation, and 17% did not face any significant degradation pressure. The novel GIS-based approach adopted in this study can act as a prototype for ascertaining the catchment-scale degradation of wetlands worldwide.