Search Results (38)

Climate change is altering global temperature and precipitation patterns, with particularly strong effects expected in Mediterranean regions, where reduced groundwater recharge and increased evapotranspiration may affect groundwater-dependent ecosystems. This study provides a preliminary, indicator-based assessment of the potential sensitivity of the Cabecera del Bornova Groundwater Body (Guadalajara, Spain), which sustains the Somolinos karst wetland, under natural conditions and protected as a Natural Groundwater Reserve and Natural Lacustrine Reserve. Empirical correlations were established between accumulated deviations of historical precipitation and observed piezometric levels in two monitoring piezometers using second-degree polynomial functions. The most informative relationships were obtained for piezometer ZE01, particularly at the daily scale, whereas the second piezometer showed weaker relationships. These functions were applied to regionalized climate projections generated with the FICLIMA methodology from ten CMIP6 models under SSP1-2.6, SSP2-4.5, SSP3-7.0 and SSP5-8.5 scenarios from the IPCC Sixth Assessment Report. The results indicate a general decreasing tendency in empirical piezometric-level indicators throughout the 21st century, although the magnitude of the response is highly sensitive to the selected rainfall station, temporal resolution, climate model and scenario. Extreme projected declines are interpreted as extrapolation-sensitive outputs rather than deterministic predictions of aquifer drawdown or groundwater-reserve depletion. Direct impacts on lagoon level, spring discharge or wetland extent cannot be quantified with the dataset. The results highlight the need to expand piezometric monitoring, instrument the Manadero del Bornova spring, monitor lagoon water levels and develop physically based recharge and groundwater-flow models. Full article

Long-term environmental change and local habitat variation may affect breeding birds in the Slovenian Karst landscape. The White Stork (Ciconia ciconia), a species associated with open agricultural and wetland mosaics, was used as the focal species. We descriptively reviewed nest records collected between 2005 and 2025 from 17 nesting sites in five municipalities. Because monitoring periods differed among sites and reproductive records were incomplete, the analysis was limited to site-year summaries of nest status, egg records, recorded young, nest persistence, and selected weather variables. Nesting patterns varied markedly among sites. Planina and Nova vas showed persistent occupancy, whereas Rakitnik and Dilce had interrupted occupancy or periods in which the nest was no longer recorded. Persistent occupancy did not consistently coincide with complete reproductive records. Postojna weather records indicated generally higher annual mean temperatures and fewer snowy days in recent years, but these patterns are presented only as regional environmental context. The study demonstrates the value of standardised, long-term nest-level monitoring for identifying local changes that broader regional summaries may obscure. Full article

Karst poljes in the Dinaric karst are widely infilled with Quaternary sediments. In the Bribir–Ostrovica karst polje, these sediments were investigated using geomorphological mapping and multiproxy analysis of lake sediment cores, including grain size, mineralogical, total organic and inorganic carbon (TOC, TIC), and ostracod analyses, coupled with radiocarbon dating. A key sediment core (OSP-3) recovered a ~470 cm long sedimentary sequence dating back to 13,200 cal yr BP. The floodplain to wetland environment occurred at the Late Pleistocene to Holocene transition (ca. 12,100 cal yr BP), evident by the first appearances of ostracods and an increase in TOC. More stable lake conditions prevailed between 9600 and 7200 cal yr BP, with dominant carbonate deposition and abundant ostracods. During the Middle and Late Holocene, increased clastic input and reduced ostracod presence indicate a shallow, dynamic water body influenced by erosion and periodic flooding. Lake sedimentation was strongly controlled by local karst topography, with a maximum lake depth of ca. 6 m. The Bribir–Ostrovica paleolake represents a rare terrestrial Holocene paleoenvironmental record from the Dinaric karst of the eastern Adriatic coast and provides valuable context for interpreting the nearby Neolithic archaeological site of Krivače as a lakeside settlement. Full article

Wetland ecosystems have been a central focus of ecological research for an quite some time. Nevertheless, the degradation of wetland riparian zones has markedly accelerated due to anthropogenic activities, climate change, and habitat heterogeneity. The objective of this paper is to investigate the differences in functional traits of riparian plants under changing wetland environments on a karst plateau, as well as to elucidate the adaptive strategies of wetland plants across different habitats. This study examines the Caohai Wetland located on the Guizhou karst plateau, selecting the leaves of four dominant plant species (Phragmites australis, Onopordum acanthium, Galium odoratum, Paspalum distichum) in the Caohai Wetland lakeshore zone and analyzes the influence of soil factors on the variation of plant functional traits within the wetland riparian zone. The results reveal that: (1) significant differences exist in the functional traits of dominant plants in the riparian zones of karst plateau wetlands, with complex interrelationships among these traits; (2) the coefficients of variation for magnesium (Mg) and calcium (Ca) in the soil are notably high (79.53% and 67.21%, respectively), whereas soil oxidation-reduction potential (ORP) exhibits the lowest coefficient of variation (4.36%)—furthermore, the convergent variation in specific leaf area (SLA) and leaf dry matter content (LDMC) directly reflects the strong environmental filtering imposed by this habitat—and (3) redundancy analysis (RDA) indicates that leaf length (LL), specific leaf area (SLA), leaf area (LA), and plant carbon content (PCC) are particularly sensitive to environmental changes, while soil calcium (Ca), total nitrogen (TN), water-dispersible clay (WDR), soil organic matter (SOM), soil moisture content (SPMC), and total potassium (TK) constitute the principal soil factors influencing plant adaptive strategies in karst plateau wetlands. In conclusion, this study demonstrates that adaptation to karst wetland habitats is mediated through trade-offs in the allocation of photosynthetic products and the regulation of carbon (C), nitrogen (N), and phosphorus (P) nutrient balances under calcium-enriched and phosphorus-limited conditions, thereby reflecting the response characteristics of functional traits in karst plateau wetland plants to environmental changes. Full article

The karst ecologically fragile region of northern Guangxi faces dual pressures from wetland shrinkage and landscape functional degradation driven by rapid urbanisation. The mechanisms governing its multi-scale landscape pattern evolution and the dominance of disturbances require urgent clarification. This study integrates land use data from 1980 to 2020, employing ArcGIS 10.8 analysis, Fragstats landscape indices, and optimal parameter geographic detectors to construct a ‘pattern-process-driver’ interpretative framework in northern Guangxi. It quantitatively reveals the evolution characteristics and driving mechanisms of wetland landscape patterns in northern Guangxi, thereby optimising wetland ecological conservation pathways. Results indicate the following: (1) Between 1980 and 2020, total wetland area decreased by 65.58 km², exhibiting a ‘structural substitution’ trend characterised by natural wetland decline and artificial wetland expansion. (2) Wetland landscape patterns exhibited intensified fragmentation and increased structural complexity. (3) Wetland evolution was primarily driven by annual mean temperature, GDP, and annual mean precipitation, reflecting a composite mechanism characterised by climate dominance, economic pressure, and policy failure. Specifically, the increase in temperature is the main reason for the decrease in natural wetlands, while economic growth dominates the expansion of artificial wetlands. This study provides scientific basis for karst wetland ecological restoration and differentiated territorial spatial planning, offering reference for ecological and environmental governance in karst watersheds. Full article

Ecological stoichiometry, as a discipline investigating plant elemental coupling mechanisms, has become a research focus across various ecosystems. However, few studies have examined plant stoichiometric characteristics in the water–land ecotone of plateau karst lake wetlands. It remains unclear whether foliar nutrient contents and stoichiometric ratios in this transitional zone vary with flooding intensity. This study established three sampling gradients (near-water area, middle area, and far-water area) within the water–land ecotone of Caohai Lake wetland in Guizhou Plateau, measuring nutrient concentrations along with their stoichiometric ratios in leaves of three dominant plant species. The results revealed significant interspecific differences in leaf nitrogen (N), phosphorus (P), potassium (K), calcium (Ca) concentrations and N:P ratios among the three dominant species, while significant spatial variations were observed in N concentration and the C:N ratio across sampling locations. Correlation analysis demonstrated significant positive relationships among leaf N, P, and K concentrations, all showing negative correlations with C concentration. Phragmites australis exhibited significantly lower C:N and N:P ratios compared to Scirpus validus and Juncus effusus, suggesting its growth advantage through rapid nutrient acquisition. This species may serve as an efficient phytoremediator for N and P absorption from both soil and water. These findings provide valuable references for vegetation selection in constructed wetlands. Full article

Nitrogen (N) is a key nutrient for sustaining ecosystem productivity and agricultural sustainability; however, achieving high-precision monitoring in wetlands with highly heterogeneous surface types remains challenging. This study focuses on Caohai, a representative karst plateau wetland in China, and integrates Sentinel-2 multispectral and Zhuhai-1 hyperspectral remote sensing data to develop a soil nitrogen inversion model based on spectral indices, texture features, and their integrated combinations. A comparison of four machine learning models (RF, SVM, PLSR, and BPNN) demonstrates that the SVM model, incorporating Zhuhai-1 hyperspectral data with combined spectral and texture features, yields the highest inversion accuracy. Incorporating land-use type as an auxiliary variable further enhanced the stability and generalization capability of the model. The study reveals the spatial enrichment of soil nitrogen content along the wetland margins of Caohai, where remote sensing inversion results show significantly higher nitrogen levels compared to surrounding areas, highlighting the distinctive role of wetland ecosystems in nutrient accumulation. Using Caohai Wetland on the Chinese karst plateau as a case study, this research validates the applicability of integrating spectral and texture features in complex wetland environments and provides a valuable reference for soil nutrient monitoring in similar ecosystems. Full article

With mounting anthropogenic pressures on groundwater supplies, practical methods for quantifying lake–groundwater exchange are critical for water resources management. This is particularly important in karst environments where surface–groundwater connectivity is often high. The White method uses nighttime water level fluctuations to estimate groundwater flux. While the White method has been applied to flooded wetlands, published lake applications are rare. This study evaluated a modified White method for estimating leakage at 28 karst lakes in Florida. The method was modified to include evaporation correction, with both nighttime and all-day approaches evaluated. Using the nighttime correction approach, average annual groundwater flux (leakage) ranged from −2.4 to +1.9 m/y, with a mean of −0.5 m/y (negative indicates lake outflow). Without nighttime evaporation correction, leakage estimates would be erroneous by an average of −0.7 m/y. The results showed no significant difference from 138 leakage values compiled from previous studies that used diverse methods. The modified White method requires special attention to evaporation, filtering criteria, and hydrogeologic context. Overall, the method provides a useful complementary approach to other methods for estimating long-term annual lake–groundwater exchange with comparatively minimal data requirements. Full article

The soil–water partition coefficient (Kd) of antibiotics is a critical indicator for assessing their migration potential in the environment. Currently, research on antibiotic Kd values in specific geological settings such as karst wetlands remains relatively limited. This study uniquely integrates partial least squares (PLS) regression with redundancy analysis (RDA), a hybrid approach that effectively handles complex environmental datasets prone to multicollinearity. The results identified Fe³⁺, NO₃⁻, and PO₄³⁻ in water, as well as clay content, organic matter, bulk density, and pH in sediments, as key factors influencing Kd through redundancy analysis. Using PLS, predictive models were developed for the logKd of four antibiotics: tetracycline (TC), doxycycline (DOX), chlortetracycline (CTC), and demeclocycline (DMC). The models demonstrated strong predictability with Q₂cum values of 0.96, 0.93, 0.99, and 0.83, respectively, indicating excellent model convergence. These findings provide important insights into how soil and water physicochemical properties influence the distribution of antibiotics, support the prediction of antibiotic transport and fate, and contribute to the exposure and risk assessment of these emerging contaminants in aquatic ecosystems. Full article

This study analyzed the changes in landscape patterns and the ecological health status of karst plateau wetlands, providing valuable insights into their conservation. Using land cover data from 1996 to 2021, DEM, and Landsat series satellite imagery, this study employed landscape ecology methods and the pressure–state–response (PSR) model framework. A regional landscape grid was constructed, and 13 indicators were selected to establish an ecological health evaluation system for karst plateau wetlands. This allowed us to explore the spatiotemporal change characteristics of the landscape pattern and the ecological health of karst plateau wetlands. The results showed that over a 25-year period, farmland, grassland, and construction land areas have increased, whereas forested land areas have decreased. Water bodies remained relatively stable but showed a trend of transitioning into grassland. Unused land showed no significant change. Landscape analysis indicated that grasslands experience the highest rate of fragmentation, complex shapes, and greater heterogeneity, whereas water bodies have the lowest fragmentation, more regular shapes, and lower heterogeneity. Other landscape types exhibited moderate characteristics. Overall, the landscape of the study area exhibited high fragmentation, specific patch aggregation, moderate patch density, and low diversity. A comprehensive ecological health evaluation revealed that the wetland health value remained at an “unhealthy” level from 1996 to 2021. Although there was a brief improvement in 2010, effective long-term recovery was not achieved. Spatially, the proportion of “diseased” areas peaked in 2006, and most grid zones remained in an “unhealthy” state over the years, with none reaching the “healthy” standard. These findings highlight the severe challenges faced by the wetland ecosystem. Full article

This study focuses on the analysis of sediment core retrieved from the deepest part (25 m) of Pirovac Bay. A long sedimentary sequence (7.45 m) supplemented by a shorter sediment core (1.45 m) from a shallower part of the bay was analyzed for sedimentological, mineralogical, geochemical, and micropaleontological (ostracod) parameters. The sediment thickness above the underlying karst paleorelief (karstic bedrock) is up to 12 m. Sediments recorded a transition from a freshwater to a marine environment starting from post-Neapolitan Yellow Tuff tephra sedimentation. First, the floodplain developed in Pirovac Bay, with intermittent pools and ponds, followed by wetland environment. The formation of a shallow freshwater paleolake during the Middle Holocene at 10 cal kyr BP was enabled by the rising sea level and high freshwater input from the karstified underground from the adjacent Lake Vrana (Biograd na Moru). The onset of marine intrusions through the karstified underground is evident with formation of a brackish lake in the Pirovac Bay basin. Marine transgression and flooding of the bay occurred at 7.3 cal kyr BP, evidenced by the geochemical and ostracod parameters, providing crucial insights into the dynamics of coastal inundation under past climate change. Intriguingly, freshwater ostracod species were still present in the marine sediments, brought into the bay from Lake Vrana through surficial canal Prosika and groundwater discharge (numerous estavelles) along the northeastern shores of the bay, proving their mutual influence. This submerged Holocene freshwater paleolake, reported here for the first time, underlines the sensitivity of coastal karst systems to the rise in sea level and serves to stress how important understanding of these processes is for effective management in coastal zone and climate change adaptation strategies. The findings provided evidence supporting the existence of coastal marine basins as freshwater lakes prior to being flooded by seawater as a consequence of the Holocene post-glacial sea level rise. Full article

The Huixian Wetland is a natural ecosystem of immense ecological value, providing crucial ecosystem services such as water purification, water regulation, and a habitat for the region’s flora and fauna. Its karst peak forest landforms and surrounding environment also possess unique ecological and landscape value. However, with the ongoing socioeconomic development, including the rise of industrial, agricultural, and aquaculture activities in the wetland area, the nutrient composition of the Huixian Wetland has been altered. This paper reviews the current status of nitrogen, phosphorus, heavy metals, emerging pollutants, and biodiversity in various environmental media of the Huixian Wetland. It synthesizes the literature to identify the factors influencing these changes and projects future research directions for the wetland. This work is of significant practical importance, providing scientific foundations for the restoration and protection of the Huixian Wetland. Full article

Agricultural activities contribute significantly to the pollution of groundwater through the incomplete absorption of nitrogen (N) and phosphorus (P). Understanding the vertical migration patterns of N and P in soil solution is crucial for controlling groundwater quality. This study is based on monitoring data of soil solution nitrogen and phosphorus at different depths (30 cm, 60 cm, 100 cm) in the Huixian Wetland Experimental Area in the Li River Basin from March to December 2021. The vertical distribution patterns of nitrogen and phosphorus in soil solution in the study area are elucidated from three aspects: seasonal variations, karst types, and land use. The results indicate that the following: (1) NO₃⁻-N is the predominant form of nitrogen, generally decreasing with increasing soil depth, while NH₄⁺-N concentrations show slight increases and TP concentrations remain relatively stable. Overall, NO₃⁻-N and TN concentrations tend to accumulate at 30 cm and 60 cm depths during both irrigation and non-irrigation seasons, with no distinct distribution patterns observed for NH₄⁺-N and TP. (2) During the irrigation season, the migration distance of NO₃⁻-N in non-karst landforms is mainly at 60 cm, while in peak forest plains, it is mainly at 100 cm, with no clear trend observed in NO₃⁻-N concentrations in peak cluster depressions. In non-irrigation seasons, the distribution of NO₃⁻-N content in non-karst landforms and peak cluster depressions is mainly 30 cm > 60 cm > 100 cm. The downward migration distance of NH₄⁺-N generally follows the order of peak cluster depressions > peak forest plains > non-karst landforms. (3) During the irrigation season, NO₃⁻-N concentrations in paddy fields remain relatively high at 100 cm, while in drylands, NO₃⁻-N concentrations generally follow the pattern of 30 cm > 60 cm > 100 cm but may exhibit anomalous increases or decreases at 60 cm and 100 cm depths during heavy rainfall. Full article

The world’s natural wetlands, which have important ecological functions, are being lost at an alarming rate. The erosion and deposition of soil on wetlands is a major cause of wetland conversion to agriculture. An urgent problem to be solved is how to slow down the erosion and deposition of wetlands resulting from land use. Land use patterns affect soil properties, thereby affecting soil aggregate stability and erodibility. Evaluating the effects of land use patterns on soil aggregate stability and erodibility in small watersheds of wetland ecosystems of karst plateau is of great importance. Thus, we compared the soil properties, aggregate stability indicators and soil erodibility of shrubland, grassland, artificial forest land and sloping farmland for evaluating the impact of various land use patterns on soil aggregate stability and erodibility in typical karst plateau wetland ecosystems. Our results showed that the mass fraction of soil aggregates > 0.25 mm was the main component in the four land uses, with greater variation in aggregates > 5 mm; overall, MWD, GMD and WSA_0.25 were higher in grassland and shrubland than in sloping farmland and artificial forest land, while K values, PAD and SCAI showed the opposite trend. Correlation analysis showed that effective soil nutrients had a positive effect on soil aggregate stability. In conclusion, the stability of soil aggregates and resistance to soil erosion were strongest under the influence of shrubland. Our study showed that shrubland can better improve soil aggregate stability and erosion resistance, which may provide a guide for protecting and restoring karst plateau wetland ecosystems. Full article

Due to the rapid exploitation of water resources in the Huixian karst wetland in the southwest of China in the past decades, the wetland has suffered from shrinkage in size and serious degradation of ecological functioning. To assess how much water within the wetland could still be taken out for local supply purposes while the wetland can still be kept in its normal ecological functioning. Through the use of multi-methods, including field surveys by a multi-disciplinary team, water balance, Remote Sensing, GIS and numerical simulation, this paper characterizes the wetland regime of the study area and finally determines scenarios of water resource utilization for local water supply within acceptable parameters of wetland ecological health. Through the analysis of the methods, it was found that the hydrological characteristics of the study area were conditioned by not only the karst water but also the regional precipitation fluctuations. A zone of mobile watersheds for Lake Mudong was established as opposed to a conventional single watershed. If the wetland ecosystem is kept at the current status of class III, a scenario of withdrawal of up to 20% of lake inflows could be accommodated. The results and their approaches would provide much-needed information for the protection of the wetland and its sustainable water utilization per se. It would offer a basic reference for similar problems in karst areas of southwest China and other areas alike. Full article