Search Results (104)

This study was developed to identify the optimal (most cost-effective) strategies to reduce sediment and phosphorus loadings in the Upper Soldier Creek, Kansas, USA, watershed using the Watershed Management Optimization Support Tool (WMOST) suite of programs. Under average precipitation, loading targets for upland total phosphorus (TP) could be met with use of grassed swales for treating urban area runoff and of contouring for agricultural runoff. For a wet year, the same target could be met, but with use of a sand filter with underdrain for the urban runoff. Both annual and daily TP loading targets from Total Maximum Daily Loads (TMDLs) were exceeded in simulations of best management practice (BMP) solutions for 14 alternative future climate scenarios. We expanded the set of BMPs to include stream bank stabilization (physical plus riparian restoration) and two-stage channel designs, but upland loading targets could not be met for either TP or total suspended solids (TSS) under any precipitation conditions. An optimization scenario that simulated the routing of flows in excess of those treated by the upland BMPs to an off-channel treatment wetland allowed TMDLs to be met for an average precipitation year. WMOST can optimize cost-effectiveness of BMPs across multiple scales and climate scenarios. Full article

International efforts are underway to implement carbon neutrality policies in rapidly changing climate conditions. This situation has strongly demanded the discovery of novel carbon sinks. The Salix genus has attracted attention as a promising carbon sink owing to its rapid growth and efficient use as a biofuel in short-rotation cultivation. The present study aims to derive an allometric equation and conduct stem analysis as fundamental tools for estimating net primary productivity (NPP) in Salix pierotii Miq. stand, which is increasingly acknowledged as an important emerging carbon sink. The allometric equations derived showed a high explanatory rate and fitness (R² ranged from 0.74 to 0.99). The allometric equations between DBH and stem volume and biomass derived in the process of stem analysis also showed a high explanatory rate and fitness (R² ranged from 0.87 to 0.94). The NPPs calculated based on the allometric equation derived and stem analysis were 11.87 tonC∙ha⁻¹∙yr⁻¹ and 15.70 tonC∙ha⁻¹∙yr⁻¹, respectively. These results show that the S. pierotii community, recognized as the representative riparian vegetation, could play an important role as a carbon sink. In this context, an assessment of the carbon absorption capacity of riparian vegetation such as willow communities could contribute significantly to achieving carbon neutrality goals. Full article

This study focuses on the Dongting Lake region in China and evaluates ecological vulnerability using the Sensitivity–Resilience–Pressure (SRP) framework, integrated with Spatial Principal Component Analysis (SPCA) to calculate the Ecological Vulnerability Index (EVI). The EVI values were classified into five levels using the Natural Breaks (Jenks) method, and spatial autocorrelation analysis was applied to reveal spatial differentiation patterns. The Geodetector model was used to analyze the driving mechanisms of natural and socioeconomic factors on EVI, identifying key influencing variables. Furthermore, the LightGBM algorithm was used for feature optimization, followed by the construction of six machine learning models—Multilayer Perceptron (MLP), Extremely Randomized Trees (ET), Decision Tree (DT), Random Forest (RF), LightGBM, and K-Nearest Neighbors (KNN)—to conduct multi-class classification of ecological vulnerability. Model performance was assessed using ROC–AUC, accuracy, recall, confusion matrix, and Kappa coefficient, and the best-performing model was interpreted using SHAP (SHapley Additive exPlanations). The results indicate that: ① ecological vulnerability increased progressively from the core wetlands and riparian corridors to the transitional zones in the surrounding hills and mountains; ② a significant spatial clustering of ecological vulnerability was observed, with a Moran’s I index of 0.78; ③ Geodetector analysis identified the interaction between NPP (q = 0.329) and precipitation (PRE, q = 0.268) as the dominant factor (q = 0.50) influencing spatial variation of EVI; ④ the Random Forest model achieved the best classification performance (AUC = 0.954, F1 score = 0.78), and SHAP analysis showed that NPP and PRE made the most significant contributions to model predictions. This study proposes a multi-method integrated decision support framework for assessing ecological vulnerability in lake wetland ecosystems. Full article

Under the global climate change context, the probability of extreme flood events has substantially increased. Nevertheless, our understanding of the post-flood dynamics in wetland ecosystems, particularly regarding soil biogeochemistry and microbiota, remains limited. Therefore, soil properties, enzyme (soil acid phosphatase, soil alkaline phosphatase, soil urease and soil protease) activities, and bacterial communities were examined in four dominant vegetation communities of Shengjin Lake’s riparian zone prior to and following an extreme flooding event. Our findings reveal a notable reduction in soil fertility, including nitrate nitrogen (NO₃⁻-N), ammonium nitrogen (NH₄⁺-N), available potassium (AK), and total phosphorus (TP), following the flood across different vegetation types. Marked enhancement of four key soil enzymatic activities was observed after flooding. Although the flooding event did not alter the dominant phyla-level bacterial taxa in the various vegetation communities, it significantly reduced the structural divergence among soil bacterial assemblages. Following the flooding event, total nitrogen (TN) emerged as a direct regulatory factor mediating the influence of vegetation communities on bacterial community composition, replacing the previous role of soil urease activity. These results highlight the profound impact of extreme flooding on plant–microbe interactions and provide critical insights into the ecological consequences of such events in wetland ecosystems. Full article

Policymakers face the challenge of increasing food and energy production while reducing nutrient pollution. Coastal hypoxic zones, often caused by human activity, are a key indicator of sustainability. The purpose of this study is to develop a novel framework that can be used by policymakers to assess strategies to reduce or eliminate hypoxic zones in coastal waters. The developed framework includes socioecological conditions by integrating the Driver–Pressure–State–Impact–Response (DPSIR) framework and multiple thinking approaches (nexus, systems, and goal-oriented) with sustainable development goals (SDGs) and their targets, the food–energy–water (FEW) nexus, agricultural conservation practices (ACPs), and the collective knowledge from the published literature and experts, all applied to hypoxia in oceans. Four categories of ACPs with potential positive effects on hypoxia were identified: conservation cropping systems, conservation drainage systems, riparian buffer systems, and wetland systems. The Gulf of Mexico, a large hypoxic zone, served as a case study. The methods from the development of this framework may be tailored to some 500 global coastal hypoxic zones, covering 245,000 km² of oceans. Full article

This study investigated the impact of land use change on water quality in the Xinxian River Basin amidst rapid urbanization. While previous studies have predominantly focused on single-scale buffer analyses or specific land use types, the interactions between multi-scale riparian buffers and diverse land cover dynamics remain rarely understudied, particularly in a rapidly urbanizing county in the Yangtze River Basin. Land use type data for the Xinxian River Basin in 2000, 2010, and 2020 were acquired using GIS technology, and subsequent analysis quantified land use pattern changes over this 20-year period. Additionally, 2023 land use data for riparian buffer zones (50 m, 100 m, 200 m, 400 m, and 600 m) were obtained via GIS and subjected to Redundancy Analysis (RDA) with 2023 water quality monitoring data to evaluate the impact of land use on water quality. The results revealed significant land use conversion dynamics, particularly between natural and anthropogenic cover types. Forest cover exhibited negative correlations with riverine nutrient concentrations, while built-up areas displayed strong positive associations, especially at finer scales (50–100 m buffers). Notably, the dominant influencing factor shifted from built-up land at smaller buffer scales (50–100 m) to forest land at larger scales (400–600 m), whereas agricultural land showed no significant correlation. These findings highlight scale-dependent relationships between land use and aquatic ecosystems, emphasizing the critical role of spatial planning in mitigating urbanization impacts. The work is conducive to the sustainable development of Longgan Lake National Wetland Nature Reserve and the protection of water ecology in the middle and lower reaches of the Yangtze River. Full article

With the acceleration of urbanization and the increased frequency of extreme rainfall events, flooding has emerged as one of the most serious natural disaster problems, particularly affecting riparian cities. This study conducted a flooding risk assessment and an analysis of the driving factors behind flood disasters in the Songhua River Basin utilizing an improved Soil Conservation Service Curve Number (SCS-CN) model. First, the model was improved by slope adjustments and effective precipitation coefficient correction, with its performance evaluated using the Nash–Sutcliffe efficiency coefficient (NSE) and the Root Mean Square Error (RMSE). Second, flood risk mapping was performed based on the improved model, and the distribution characteristics of the flooding risk were analyzed. Additionally, the Geographical Detector (GD), a spatial statistical method for detecting factor interactions, was employed to explore the influence of natural, economic, and social factors on flooding risk using factor detection and interaction detection methods. The results demonstrated that the improvements to the SCS-CN model encompassed two key aspects: (1) the optimization of the CN value through slope correction, resulting in an optimized CN value of 50.13, and (2) the introduction of a new parameter, the effective precipitation coefficient, calculated based on rainfall intensity and the static infiltration rate, with a value of 0.67. Compared to the original model (NSE = 0.71, rRMSE = 19.96), the improved model exhibited a higher prediction accuracy (NSE = 0.82, rRMSE = 15.88). The flood risk was categorized into five levels based on submersion depth: waterlogged areas, low-risk areas, medium-risk areas, high-risk areas, and extreme-risk areas. In terms of land use, the proportions of high-risk and extreme-risk areas were ranked as follows: water > wetland > cropland > grassland > shrub > forests, with man-made surfaces exacerbating flood risks. Yilan (39.41%) and Fangzheng (31.12%) faced higher flood risks, whereas the A-cheng district (6.4%) and Shuangcheng city (9.4%) had lower flood risks. Factor detection results from the GD revealed that river networks (0.404) were the most significant driver of flooding, followed by the Digital Elevation Model (DEM) (0.35) and the Normalized Difference Vegetation Index (NDVI) (0.327). The explanatory power of natural factors was found to be greater than that of economic and social factors. Interaction detection indicated that interactions between factors had a more significant impact on flooding than individual factors alone, with the highest explanatory power for flood risk observed in the interaction between annual precipitation and DEM (q = 0.762). These findings provide critical insights for understanding the spatial drivers of flood disasters and offer valuable references for disaster prevention and mitigation strategies. Full article

One question about historical grassland ecosystems in the Great Plains region of central North America is the percentage of tree cover overall and near major rivers, compared to current tree cover. Here, I assessed tree cover in reconstructions of historical grasslands in the eastern Great Plains, isolating tree cover adjacent to major rivers, and then compared historical land cover to current (year 2019) land cover. As an extension to supply information for the entire Great Plains region, I modeled historical cover. For the 28 million ha extent of the eastern Great Plains, historical land cover was 86% grasslands and 14% trees, but 57% grasslands and 43% trees within 100 m of rivers. Tree cover near rivers ranged from 5.4% to 90% for 15 large river watersheds, indicating that any amount of tree cover could occur near rivers at landscape scales. Currently, the overall extent was 3.6% herbaceous vegetation and 6.6% forested, with 82% crops and pasture and 8% development. Within 100 m of rivers, crop and pasture decreased to 44% of cover, resulting in 14% herbaceous cover and 38% forested cover. Current tree cover ranged from 6.2% to 66% near rivers in 15 watersheds, which was relatively comparable to historical tree cover (ratios of 0.6 to 1.5). Results generally were similar for combined tree and shrub cover modeled for the entire Great Plains. Variability, even at landscape scales of large watersheds, was the normal condition for tree cover in grasslands and riparian ecosystems of the Great Plains. In answer to the question about tree cover in historical grassland ecosystems in the eastern Great Plains, tree cover typically was about three-fold greater near rivers than tree cover throughout grasslands. Combined tree and shrub cover near rivers was more than two-fold greater than tree and shrub cover throughout the Great Plains. Riparian forest restoration, as a management practice to reduce streambank erosion, overall has been effective, as indicated by current tree cover (38% near rivers in the eastern Great Plains) comparable to historical tree cover (43% near rivers in the eastern Great Plains), albeit as measured at coarse landscape scales with dynamics in vegetation and river locations. As a next step, restoration of grassland vegetation and non-riparian wetlands likely will help reestablish infiltrative watersheds, augmenting riparian forest restoration. Full article

Clarifying carbon (C), nitrogen (N), and phosphorus (P) ecological stoichiometry helps us to understand the ecological functions of wetland ecosystems. This study investigated the variations in ecological stoichiometry and their driving factors in the Yellow River wetland. Soil and plant samples were collected and analyzed from riparian lower-beach wetland (LBW), riparian higher-beach wetland (HBW), and depressional wetland (DW) at the junction of the middle and lower reaches of the Yellow River, respectively. Compared with HBW, DW exhibited higher soil C/N (9.15 ± 0.13), C/P (11.17 ± 0.52), and N/P (1.08 ± 0.09) (p < 0.01), indicating its stronger C and N storage capacity. At the community level, higher plant C/N and C/P in LBW (21.47 ± 1.61 and 206.80 ± 1.75, respectively) and HBW (22.91 ± 0.90 and 241.04 ± 3.28, respectively) compared to DW (14.44 ± 1.02 and 115.66 ± 2.82, respectively) (p < 0.01) suggested that plants in LBW and HBW had greater C assimilation and nutrient use efficiency. Soil electrical conductivity (EC) and hydrolyzed N (SHN) positively affected soil ecological stoichiometry (p < 0.01). In contrast, soil EC, soil organic C, dissolved organic C, and SHN negatively altered plant stoichiometric ratios (p < 0.05), which were regulated by plant functional groups. When pooling all wetlands, stoichiometric ratios of plants were closely correlated with those of soil (p < 0.05). These findings demonstrate that wetland types notably affect soil and plant stoichiometry. Wetland types exerted opposite effects on soil and plant stoichiometry due to the different influences of soil physicochemical properties and the coupling effects of nutrient and stoichiometry between soil and plants. Therefore, the interactions between plant and soil stoichiometry should be considered to explore the C and nutrient cycles in riverine wetlands. Our research emphasizes the necessity of considering wetland type differences and intricate plant–soil stoichiometric interactions in formulating management strategies and maintaining the sustainability of wetlands. Full article

Aims: The functional traits of twigs and leaves are closely related to the ability of plants to cope with heterogeneous environments. The analysis of the characteristics of twigs and leaves and leaf thermal dissipation in riparian plants is of great significance for exploring the light energy allocation and ecological adaptation strategies of plant leaves in heterogeneous habitats. However, there are few studies on the correlation between the twig–leaf characteristics of riparian plants and their heat dissipation in light heterogeneous environments. Methods: In this study, the riparian plant Hippophae rhamnoides in Taohe National Wetland Park was the research object. According to the differences in the canopy light environment of the H. rhamnoides population, three habitat gradients were set: I, the full sight zone; II, the moderate shade zone; and III, the canopy cover zone. We studied the relationship between the twig–leaf characteristics of H. rhamnoides and leaf thermal dissipation in a heterogeneous light environment. Important Findings: The results are as follows: from the full sight zone to the canopy cover zone, the population characteristics and the twig, leaf, and photosynthetic fluorescence physiological characteristics of H. rhamnoides demonstrated significant changes (p < 0.05). In the full sight zone, H. rhamnoides tended to have thick leaves with a smaller SLA on short and thick twigs, and the light energy absorbed by the leaves accounted for a higher proportion of thermal dissipation. In the moderate shade zone, H. rhamnoides tended to grow many thin leaves with high SLA on long and thick twigs, and the proportion of light energy absorbed by the leaves for heat dissipation was lower than that in the full sight zone. In the canopy cover zone, H. rhamnoides tended to grow a few large and thick leaves with a low SLA on slender and long twigs, and the proportion of light energy absorbed by the leaves for heat dissipation was the lowest. There was a significant correlation between the twig–leaf and leaf heat dissipation of H. rhamnoides in the three habitats (p < 0.05). The co-variation of plant branches and leaves and the timely adjustment of thermal dissipation in photoheterogeneous habitats reflect the phenotypic plasticity mechanism and self-protection strategy of riparian plants in adapting to heterogeneous environments. Full article

The soil microbiome plays an important role in wetland ecosystem services and functions. However, the impact of soil hydrological conditions on wetland microorganisms is not well understood. This study investigated the effects of wetted state (WS); wetting–drying state (WDS); and dried state (DS) on the diversity of soil bacteria, fungi, and archaea. The Shannon index of bacterial diversity was not significantly different in various flooding conditions (p > 0.05), however, fungal diversity and archaeal communities were significantly different in different flooding conditions (p < 0.05). Significant differences were found in the beta diversity of bacterial, fungal, and archaeal communities (p < 0.05). Additionally, the composition of bacteria, fungi, and archaea varied. Bacteria were predominantly composed of Proteobacteria and Actinobacteria, fungi mainly consisted of Ascomycota and Mucoromycota, and archaea were primarily represented by Crenarchaeota and Euryarchaeota. Bacteria exhibited correlations with vegetation coverage, fungi with plant diversity, and archaea with aboveground vegetation biomass. The pH influenced bacterial and archaeal communities, while soil bulk density, moisture, soil carbon, soil nitrogen, and plant community diversity impacted fungal communities. This study provides a scientific basis for understanding the effects of different hydrological conditions on microbial communities in the Huihe Nature Reserve; highlighting their relationship with vegetation and soil properties, and offers insights for the ecological protection of the Huihe wetland. Full article

Coastal wetlands deliver essential ecosystem services, including cultural services, which provide non-material benefits such as recreation, education, and spiritual enrichment that are crucial for human well-being. This study investigates the cultural ecosystem services provided by a 40 ha coastal wetland in the Gulf of Manfredonia, southern Italy, within the Gargano National Park. By integrating an ecological survey of the bird community with a social survey of visitors to the King’s Lagoon Nature Reserve, the content of tailored planning strategies and management tools for the conservation of wetland biodiversity was developed. An ecological analysis of the bird community was carried out on the assumption that it could be representative of the total biodiversity observed in the wetland. On the other hand, a questionnaire was used to collect information from visitors to the reserve, highlighting the aspects of the wetland that they found most interesting and attractive according to their judgement and beliefs, and thus targeting a specific set of cultural ecological services. The two approaches were then combined to develop a comprehensive strategy. The bird community analysis led to the identification of the mixed biotope category (a combination of wetlands, aquatic/riparian ecosystems, semi-natural vegetated areas, and meadows together with agricultural areas) as the reference biotope for prioritizing wetland management. The Ardeidae family was chosen as a bird flagship group because of its high visibility, ease of identification, attractiveness to visitors, wide local distribution, and fairly constant presence in the study area throughout the year. Flagship species have a dual function: to guide conservation measures and actions by wetland managers, and to attract the interest, curiosity and active participation of potential visitors to the wetland. Based on the results, a list of guidelines for improving the birds’ habitats and providing them with resources (feeding, breeding, shelter, roosting, etc.) has been proposed. The aim of these measures is to optimize the presence and abundance of Ardeidae as flagship species, thereby preserving the biodiversity heritage in general and increasing the provision of cultural ecosystem services in the wetland. The resulting dynamic interplay ensures that both natural and cultural resources are fully and appropriately valued, protected, and maintained for the benefit of present and future generations. Full article

In the central region of Chile, the Mega-Drought together with the demographic increase near the coast threatens groundwater availability and the hydrogeological functioning of coastal wetlands. To understand the hydric relationship between an aquifer and a wetland in a semi-arid coastal region of Central Chile (Valparaíso, Chile), as well as its geoenvironmental effects, four data collection campaigns were conducted in the wetland–estuary hydric system and surroundings, between 2021 and 2022, including physical, hydrochemical, and isotopic analyses in groundwater (n = 16 sites) and surface water (n = 8 sites). The results generated a conceptual model that indicates a hydraulic connection between the wetland and the aquifer, where the water use in one affects the availability in the other. With an average precipitation of 400 mm per year, the main recharge for both systems is rainwater. Three specific sources of pollution were identified from anthropic discharges that affect the water quality of the wetland and the estuary (flow from sanitary landfill, agricultural and livestock industry, and septic tank discharges in populated areas), exacerbated by the infiltration of seawater laterally and superficially through sandy sediments and the estuary, increasing salinity and electrical conductivity in the coastal zone (i.e., 3694 µS/cm). The Del Sauce subbasin faces strong hydric stress triggered by the poor conservation state of the riparian–coastal wetland and groundwater in the same area. This study provides a detailed understanding of hydrological interactions and serves as a model for understanding the possible effects on similar ecosystems, highlighting the need for integrated and appropriate environmental management. Full article

Wetland ecosystems are experiencing rapid degradation due to human activities, particularly the diversion of natural flows for various purposes, leading to significant alterations in wetland hydrology and their ecological functions. However, understanding and quantifying these eco-hydrological changes, especially concerning inundation dynamics, presents a formidable challenge due to the lack of long-term, observation-based spatiotemporal inundation information. In this study, we classified wetland areas into ten equal-interval classes based on inundation probability derived from a dense, 30-year time series of Landsat-based inundation maps over an Australian dryland riparian wetland, Macquarie Marshes. These maps were then compared with three simplified vegetation patches in the area: river red gum forest, river red gum woodland, and shrubland. Our findings reveal a higher inundation probability over a small area covered by river red gum forest, exhibiting persistent inundation over time. In contrast, river red gum woodland and shrubland areas show fluctuating inundation patterns. When comparing percentage inundation with the Normalized Difference Vegetation Index (NDVI), we observed a notable agreement in peaks, with a lag time in NDVI response. A strong correlation between NDVI and the percentage of inundated area was found in the river red gum woodland patch. During dry, wet, and intermediate years, the shrubland patch consistently demonstrated similar inundation probabilities, while river red gum patches exhibited variable probabilities. During drying events, the shrubland patch dried faster, likely due to higher evaporation rates driven by exposure to solar radiation. However, long-term inundation probability exhibited agreement with the SAGA wetness index, highlighting the influence of topography on inundation probability. These findings provide crucial insights into the complex interactions between hydrological processes and vegetation dynamics in wetland ecosystems, underscoring the need for comprehensive monitoring and management strategies to mitigate degradation and preserve these vital ecosystems. Full article

Plant organ biomass allocation and morphological characteristics are important functional traits. The responses of plant root, stem, and leaf traits to heterogeneous habitats in floodplain wetlands are highly important for understanding the ecological adaptation strategies of riparian plants. However, the patterns of these responses remain unclear. In a floodplain wetland in the middle reaches of the Heihe River, we studied the responses of the root, stem, and leaf morphological traits and biomass allocation of Leymus secalinus to varying habitat conditions. We measured these traits in three sample plots, delineated based on distance from the riverbank: plot I (near the riparian zone, 50–150 m from the riverbank), plot II (middle riparian zone, 200–300 m from the riverbank), and plot III (far riparian zone, 350–450 m from the riverbank). The results showed that in plot I, L. secalinus tended to have slender roots and stems and small leaves, with a biomass allocation strategy that maximized the root–shoot ratio (RSR). In plot II, L. secalinus had thick stems and moderate leaf and root patterns, and the RSR values were between those of plot I and plot III. In plot III, L. secalinus had thin and short stems and large leaves; furthermore, among the root morphological structures, plot III had the shortest Rhizome length (RL) and longest Rhizome diameter (RD), and the RSR was the lowest. Moreover, there was a significant correlation between organ biomass and leaf thickness, stem length, RD, and RL in the three habitats (p < 0.05). By balancing the biomass allocation among organs, wetland plants in floodplains balance changes in root, stem, and leaf morphological characteristics to improve their environmental adaptation. Full article