Assessment Of Ecological Status Research Articles

Methods for Extracting Fractional Vegetation Cover from Differentiated Scenarios Based on Unmanned Aerial Vehicle Imagery

Fractional vegetation cover (FVC) plays a key role in ecological and environmental status assessment because it directly reflects the extent of vegetation cover and its status, yet vegetation is an important component of ecosystems. FVC estimation methods have evolved from traditional manual interpretation to advanced remote sensing technologies, such as satellite data analysis and unmanned aerial vehicle (UAV) image processing. Extraction methods based on high-resolution UAV data are being increasingly studied in the fields of ecology and remote sensing. However, research on UAV-based FVC extraction against the backdrop of the high soil reflectance in arid regions remains scarce. In this paper, based on 12 UAV visible light images in differentiated scenarios in the Ebinur Lake basin, Xinjiang, China, various methods are used for high-precision FVC estimation: Otsu’s thresholding method combined with 12 Visible Vegetation Indices (abbreviated as Otsu-VVIs) (excess green index, excess red index, excess red minus green index, normalized green–red difference index, normalized green–blue difference index, red–green ratio index, color index of vegetation extraction, visible-band-modified soil-adjusted vegetation index, excess green minus red index, modified green–red vegetation index, red–green–blue vegetation index, visible-band difference vegetation index), color space method (red, green, blue, hue, saturation, value, lightness, ‘a’ (Green–Red component), and ‘b’ (Blue–Yellow component)), linear mixing model (LMM), and two machine learning algorithms (a support vector machine and a neural network). The results show that the following methods exhibit high accuracy in FVC extraction across differentiated scenarios: Otsu–CIVE, color space method (‘a’: Green–Red component), LMM, and SVM (Accuracy > 0.75, Precision > 0.8, kappa coefficient > 0.6). Nonetheless, higher scene complexity and image entropy reduce the applicability of precise FVC extraction methods. This study facilitates accurate, efficient extraction of vegetation information in differentiated scenarios within arid and semiarid regions, providing key technical references for FVC estimation in similar arid areas.

Using machine learning for the assessment of ecological status of unmonitored waters in Poland

Advancements in Artificial Intelligence (AI) technology allow for development of new tools for analytics and management which present new opportunities in field of environmental protection. The following study showcases usage of Machine Learning (ML) techniques as a complementary method for water status assessment of water bodies. Since the main goal of Water Framework Directive (WFD) is to improve the quality of water and reach good status in all the water bodies across Europe intensive monitoring program was launched together with water status assessment procedure. Based on requirements of the European Union’s WFD concerning ecological status assessment it is presented how ML can be used for assessment of Polish unmonitored river water bodies. Due to the absence of monitoring data, the foremost challenge lay in securing relevant alternative data which was set to be anthropogenic pressures. The pivotal solution was implementation of ML techniques which enable processing of seemingly unrelated information concerning pressures in the catchment. Decision Tree, Random Forest, KNN, Support Vector Machine, Multinomial Naive Bayes, XGBoost models have been tested and the results indicated most suitable techniques. Study shows highest efficiency of XGBoost and Random Forest algorithms for classification of unmonitored water bodies. The models were compared by their overall accuracy (OA) reaching approximately 93% for binary classification and 72% for comprehensive classification as well as partial class accuracies and the Probability of Misclassification (PoM) parameter. The analyses demonstrates a practical application of AI in assessment of unmonitored water bodies in case of binary classification used for reporting water status objectives of WFD as well as possible usage of full classification for planning and operational uses. OA and PoM are postulated as the best measures of goodness of classification.

Assessment of Ecological Status of Streams by Macrophyte Biological Index in Kahramanmaras Province (Turkiye)

Assessment of Ecological Status of Streams by Macrophyte Biological Index in Kahramanmaras Province (Turkiye)

Environmental Variables Significance for Ecological Status Assessment in the Bulgarian Eastern Continental Shallow Lakes

Environmental Variables Significance for Ecological Status Assessment in the Bulgarian Eastern Continental Shallow Lakes

DNA-based marine benthic assessment methods can perform as morphological ones, but an intercalibration is needed

There is an increasing need for legislation worldwide to monitor and assess the ecological status of marine ecosystems, due to increasing pressures from human activities. The costs and time of traditional analyses are high, while methods based on molecular analysis could reduce these costs and shorten evaluation times significantly. Some biotic indices used to assess the status need reference conditions to be applied. Hence, our objective here is to develop reference conditions for a molecular-based benthic index (M−gAMBI), which can be compared with a morphological one (M−AMBI). Using 6 years of data from estuaries and coasts, we have been able to set reference conditions for five water types, including richness, diversity and AMBI. However, one problem is the absence of the whole human pressure gradient in all water types, making difficult to validate the reference conditions. Based on the results of this research, the M−gAMBI index could be considered suitable for ecological status assessment since it meets most of the criteria for considering a genomics-based index suitable. However, it is considered necessary to advance in (i) improving the detection of errors in genomic methods and similarity with morphological methods, and (ii) an intercalibration exercise, allowing adjusting quality class boundaries and determining the ecological status in an equivalent manner using both methods.

Biodiversity, Ecological Status and Ecosystem Attributes of Agricultural Ditches Based on the Analysis of Macroinvertebrate Communities

Ditches are widespread and common elements of the agricultural landscape. Although they can provide habitats for aquatic biodiversity, their ecosystem integrity and processes are generally limited or even unknown due to anthropogenic pressures and the paucity of studies on this type of aquatic ecosystem. This study aimed to enhance the knowledge on the biodiversity, ecosystem attributes and ecological status of agricultural ditches by analyzing the macroinvertebrate communities of six different ditches and those of the main river in the same area. While negligible differences in taxonomic richness were observed, macroinvertebrate community composition significantly varied among sites as a function of the heterogeneous habitat conditions. These compositional differences strongly affected the relative abundance of functional feeding groups among sites and their derived ecosystem attributes. Moreover, the ecological status assessment depicted different scenarios depending on the biomonitoring indices applied. By means of a multifaceted, but still poorly adopted, analysis of the macroinvertebrate community, ranging from the taxonomic and functional diversity to ecosystem attributes and biomonitoring indices, the results obtained in this study offer useful information on the ecology of agricultural ditches with potential insights to improving their management.

Ecological Status Assessment of Permafrost-Affected Soils in the Nadym Region, Yamalo-Nenets Autonomous District, Russian Arctic

Permafrost-affected regions in the Russian Arctic are a critical study area for studying the sources of metal elements (MEs) in soils originating from geological/pedogenic processes or from anthropogenic sources via atmospheric transport. In the Nadym region of the Yamalo-Nenets Autonomous District, we investigated the contents of soil organic carbon (SOC), total nitrogen (TN), and MEs across different soil types and horizons, explored the source apportionment of MEs, and assessed local ecological risks of potentially toxic elements (PTEs). The results showed that (1) the contents of SOC and TN in Histic Cryosols (8.59% and 0.27%) were significantly higher than in Plaggic Podzols (Arenic, Gelic, and Turbic) (2.28% and 0.15%) and in Ekranic Technosols (Umbric) (1.32% and 0.09%); (2) the concentrations of MEs in the Nadym region were lower than in other Arctic regions; (3) the primary sources of MEs were identified as geological processes (36%), atmospheric transport (23%), agricultural activities (21%), and transportation (20%); and (4) the permafrost-affected soils in the Nadym region exhibited low ecological risks from PTEs. These results underscore the critical role of geological and anthropogenic factors in shaping soil conditions and highlight the relatively low ecological risk from PTEs, providing a valuable benchmark for future environmental assessments and policy development in Yamal permafrost regions.

Assessment of river ecological status in the French West Indies based on diatom flora

The Water Framework Directive (WFD) requires member states to routinely assess the river ecological status using community-based indices. However, there is still a lack of published WFD-compliant methods for the French West Indies, especially using diatom-based indices. Martinique and Guadeloupe exhibit diverse landscapes shaped by their complex geological history and tropical climatic conditions. These strong particularities make the existing indices developed for the European mainland unusable. Based on diatom sampling from to 2013 (607 samples) and through multivariate analyses, we developed the Indice Diatomique des Antilles (IDA). We first identified the key abiotic factors influencing diatom communities on both islands, and then characterized taxon sensitivity by considering their presence probability along a pressure gradient.. The index was based on the presence and relative abundance of these taxa in each sample. The last step consisted of using new data from the 2014–2022 sampling surveys (457 samples) as a validation dataset to verify IDA accuracy. Our results suggest that the IDA methodology is well designed to assess the ecological status of rivers in the West Indies.

Can the Ecological Quality of Several Bays in South Korea Be Accurately Assessed Using Multiple Benthic Biotic Indices?

Bays are extensively impacted by human activities, and an accurate assessment of ecological quality is crucial for the environmental management and protection of bays. Most studies indicate that evaluating the ecological quality of bays using a single index presents challenges. In our study, we used five benthic biotic indices and a composite index to assess the ecological quality of three bays in South Korea. Our results revealed disparities in the ecological quality status assessment using five benthic biotic indices. The composite index performed better than the other benthic biotic indices in a principal coordinate analysis. Significant differences were observed between the values classifying stations as having an acceptable or unacceptable final ecological quality in terms of species indices (except for the Pielou’s evenness index) and the abundance of opportunist species (p < 0.05). Consequently, we advocate for using a composite index to assess the ecological quality of the bays of the West Sea of South Korea. Furthermore, our study provides valuable information for marine ecological management and policy formulation in Korea and offers recommendations for using the composite index in future research.

Assessment of benthic ecological status and heavy metal contamination in an estuarine intertidal mudflat in the Northern Bohai Sea

Evaluating the ecological quality and pollution status of coastal mudflats is crucial for environmental protection and management, particularly when these areas serve as major shellfish production hotspots. In this study, we assessed the benthic ecological quality and heavy metals pollution in Geligang, located in the Northern Bohai Sea using the macrobenthos diversity index and the heavy metal pollution index. The Shannon-Wiener index (H′), AZTI marine biotic index (AMBI), multivariate AMBI (M-AMBI) showed that the benthic ecological quality in Geligang is either good or high. The potential ecological risk index and geoaccumulation index highlighted that cadmium (Cd) and mercury (Hg) as the primary heavy metal pollutants in Geligang. Surprisingly, the biomass of the two dominant species other than these indices serve as reliable indicators of heavy metal pollution. This suggests that the biomass of Mactra veneriformis and Potamocorbula laevis could be used to assess heavy metal pollution levels in Geligang.

Assessment of ecological status of Uppanar and Vellar estuaries through multivariate pollution indices

Multivariate pollution degree indices were utilized to evaluate the environmental condition of the Uppanar and Vellar estuaries. The Trophic Index (TRIX) indicates a state of “moderate eutrophication” with a value of 4.92, while the Trophic State Index (TSI) ranged from 40.3 to 57.2, categorizing the trophic states from “oligotrophic” to “eutrophic”. The Comprehensive Pollution Index (CPI) showed a range of 0.13 to 0.94, classifying pollution levels from “unpolluted” to “slightly polluted”. The study revealed that the Uppanar and Vellar estuaries underwent seasonal variations, transitioning from an oligotrophic state during the post-monsoon and summer periods to a eutrophic state in the pre-monsoon and monsoon seasons. The application of multivariate statistical tools allowed the identification of pollution indicator species to assess the estuarine systems. The insights gained from this study can be valuable for assessing other ecosystems facing similar anthropogenic activities, providing a basis for informed management and conservation strategies.

Preliminary Checklist of Ferns and Lycophytes in the Upper Montane Forest of Mt. Balatukan, Gingoog City, Southern Philippines

A preliminary species checklist of ferns and lycophytes in the upper montane forest of Mt. Balatukan, Gingoog City, Southern Philippines was provided, including their conservation and ecological status assessments. Specimens were collected through repeated transect walks. Species inventory revealed a total of 112 species (16 were lycophytes and 97 were ferns) belonging to 61 genera and 23 families. The top five families with the highest species richness are Polypodiaceae, Lycopodiaceae, Dryopteridaceae, Hymenophyllaceae, and Lindsaeaceae. In addition, most of the collected specimens were terrestrial and epiphytic. In terms of its conservation status and ecological status, out of 16 threatened species, seven are endangered (Phlegmariurus salvinoides, P. squarossus, Dicksonia mollis, Lepisorus platyrhynchos, Ophioglossum ramosii, O. pendulum, and Tmesipteris zamorarum), five are vulnerable (Alsophila fuliginousa, Asplenium vittaeforme, Aglaomorpha cornucopia, Botrychium daucifolium, and Sphaeropteris elmeri), three are other wildlife species (Lindsaea apoensis, Polystichum elmeri, and Callisopteris apiifolia), and only one other threatened species (Angiopteris evecta). Lastly, nine species of pteridophytes are widely distributed in the Philippines, and one species is narrowly distributed in Mindanao, with the family Lindsaeaceae and Polypodiaceae having the highest number of endemic species.

Current Ecological State of the Volga-Akhtuba Floodplain Water Bodies (Using the Example of Dudachenok Shallow Channel)

Current ecological state assessment of the water body located on the Volga-Akhtuba floodplain territory (Dudachenok shallow channel) after its environmental rehabilitation was carried out. It was found that almost all the studied indicators correspond to the approved quality standards with the exception of strontium – 4.5 mg/l (MPC – 0.4 mg/l (Order No. 552 dated December 13, 2016), MPC – 7 .0 mg/l (SanPiN 1.2.3685-21 No. 2 dated January 28, 2021)) and barium – 1.25 mg/l (MPC– 0.74 mg/l (Order No. 552 dated December 13, 2016), MPC – 0.7 mg/l (SanPiN 1.2.3685-21 No. 2 dated January 28, 2021)). It is concluded that it is possible to assign a hydrocarbonate class (predominant anion), calcium group (predominant cation) and second type to a water body. A study of bottom sediments revealed that chloride (36 mg/kg) is one of the predominant anions, calcium (27 mg/kg) and sodium (27 mg/kg) are the predominant cations, which agrees with the obtained water chemical composition data. Chemical and toxicological parameters of bottom sediments were analyzed. It was determined that the quantitative content of metals and pesticides does not exceed the maximum permissible concentrations.

Earth Observation-Based Cyanobacterial Bloom Index Testing for Ecological Status Assessment in the Open, Coastal and Transitional Waters of the Baltic and Black Seas

The use of Earth Observation (EO) for water quality monitoring has substantially raised in the recent decade; however, harmonisation of EO-based indicators across the seas to support environmental policies is in great demand. EO-based Cyanobacterial Bloom Index (CyaBI) originally developed for open waters, was tested for transitional and coastal waters of the Lithuanian Baltic Sea and the Ukrainian Black Sea during 2006–2019. Among three tested neural network-based processors (FUB-CSIRO, C2RCC, standard Level-2 data), the FUB-CSIRO applied to Sentinel-3 OLCI images was the most appropriate for the retrieval of chlorophyll-a in both seas (R2 = 0.81). Based on 147 combined MERIS and OLCI synoptic satellite images for the Baltic Sea and 234 for the Black Sea, it was shown that the CyaBI corresponds to the eutrophication patterns and trends over the open, coastal and transitional waters. In the Baltic Sea, the cyanobacteria blooms mostly originated from the central part and the outflow of the Curonian Lagoon. In the Black Sea, they occurred in the coastal region and shelf zone. The recent decrease in bloom presence and its severity were revealed in the areas with riverine influence and coastal waters. Intensive blooms significantly enhanced the short-term increase in sea surface temperature (mean ≤ 0.7 °C and max ≤ 7.0 °C) compared to surrounding waters, suggesting that EO data originating from thermal infrared sensors could also be integrated for the ecological status assessment.

The effect of salinity and altitude on diatom assemblages and ecological status assessment based on diatom indices in the lentic systems of the Western Mediterranean Basin (Türkiye)

AbstractIn this study, littoral diatoms and environmental variables were sampled three times in 2017 (spring, summer, and autumn) to determine the effect of salinity (SAL) and altitude (ALT) on the littoral diatom assemblages (composition, distribution, species richness and diversity) of 12 lentic systems in the Western Mediterranean Basin. Due to the SAL and ALT differences in these systems, they were distinguished under two groups (high elevated freshwater lentic systems [HEF] and hyposaline lentic systems [HYP]). The Bray–Curtis and Canonical Correspondence (CCA) analyses based on diatom species also confirmed this separation. In HYP, SAL and alkalinity (ALK) were the most effective parameters on diatom assemblage. On the other hand, diatom assemblage was mainly affected by ALT in HEF. For the biological assessment of these systems, seven diatom indices were implemented. Although most of the indices showed higher regression with SAL and ALT, they did not give the intended result in the evaluation of HYP. On the other hand, the most consistent index with environmental variables and dominant species in HEF was the Generic Diatom Index (IDG).

Assessment of Ecological Quality Status of Western Nigeria Offshore Waters (Gulf of Guinea) Using Macrobenthic Assemblage

Assessment of Ecological Quality Status of Western Nigeria Offshore Waters (Gulf of Guinea) Using Macrobenthic Assemblage

Minor effect of wind exposure and littoral slope on macrophyte characteristics in non-impacted lowland lakes of Poland.

Aquatic vegetation is a reliable indicator of the ecological condition of surface waters. Abundance, composition and spatial structure of aquatic communities are shaped by an array of factors, which include both natural abiotic features of an ecosystem and external influences. We investigated whether the physical features, i.e., wind exposure and slope of the lake basin, have a significant impact on the taxonomic composition and spatial structure of macrophyte communities from non-impacted, highly alkaline, lowland lakes of the European plains (Poland). We further examined whether these features can affect the classification of the ecological status of lakes assessed in accordance with the Water Framework Directive requirements. Morphological, botanical and physicochemical data from 260 transects in 16 non-disturbed lakes of Polish lowlands surveyed in the years 2011-2016 were analysed. For each transect, littoral slope and wind exposure were calculated. Additionally, the total phosphorus concentration was used as a proxy of water trophy. The relationships between environmental variables and macrophyte indices as well as the syntaxonomic composition of aquatic and rush vegetation (dependent variables) were analysed using multidimensional ordination techniques (redundancy analysis, variation partitioning and indicator values), correlation and regression analysis. Among the three analysed environmental factors (littoral slope, wind exposure and water trophy), in almost all cases the latter explained the highest variance in the macrophyte community, while the contribution of the first two was at most moderate, weak or usually statistically insignificant. However, lakes with steeper slopes were more frequently inhabited by stoneworts and had better ecological status than those with a gentle littoral shape. This may be attributed to the links between lake morphometry and rate of eutrophication, with deep lakes supporting more effective dilution of substances. Furthermore, lower light requirements of charophytes than of higher plants and the capacity to growth in unstable sediments facilitate charophyte establishment in deeper and steeper parts of the littoral over higher plants. Our findings suggest that in lowland lakes with relatively small areas, moderate depths and low wind exposure typical of European plains, slopes and weaving do not hamper vegetation development and do not negatively affect the macrophyte assessment of ecological status. In such ecosystems, eutrophication seems to be a more important factor determining aquatic vegetation than physical features.

A diatom-based approach to refine nutrient concentrations compatible with the “good” status of Northern Italy rivers

The identification of ecologically sound thresholds represents an important step toward improving the ecological status of rivers through appropriate measures to contain nutrient loads. The aim of the present study was to estimate phosphorus and nitrogen concentrations compatible with the achievement of the “good” ecological status of rivers from data collected in the Po River District, the largest hydrographic system in Italy. For this purpose, relationships between the diatom index used in Italy for the national assessment of the stream ecological status, the ICMi (Intercalibration Common Metric index), and total phosphorus and nitrate concentrations were analyzed using monitoring data collected between 2009 and 2019. The Po River Basin encompasses five distinct river types, from Alpine to Mediterranean to Lowlands, characterized by different anthropogenic pressures and water quality. Through regression analysis between the ICMi and nutrient concentrations, we estimated ranges of the latter values corresponding to a “good” ecological status for each river type. The resulting thresholds are far more stringent than the limits set by the Italian legislation for water quality classification. This is particularly true for total phosphorus, whose threshold value should be roughly halved for all river types. For nitrates, the results are more differentiated according to river type: the estimated thresholds are much more stringent than those currently in use for siliceous Alpine and Mediterranean rivers. Moreover, the availability of such a large database allowed also to assess the influence of one nutrient over the other on the diatom community and to highlight some critical issues in the formulation of ICMi for Mediterranean rivers.

Halamphora taxa in Hungarian soda pans and shallow soda lakes detected via metabarcoding and microscopic analyses

The research presented investigates whether DNA-based metabarcoding can replace the morphology-based identification of diatom taxa in the ecological status assessments of aquatic habitats. When comparing data obtained with microscopy and metabarcoding, significant deviations have been noticed. One of the main reasons includes the incompleteness of the reference database used for taxonomic annotation of sequences. The database library should be complemented with species inhabiting unique habitats and having specific environmental requirements representing environmental endpoints for genetic diversification. Soda pans and soda lakes are examples of an extreme habitat with the loss of sodic character as the main threat; thus, accurate identification of species and exact information on their salinity tolerance is essential for adequate ecological status assessment. In the present study, by using microscopy and metabarcoding, we investigated taxa of the genus Halamphora that are common in soda pans and soda lakes. We detected six species of which Halamphora dominici and H. veneta occurred frequently and often in high abundance (it was often dominant having relative abundance higher than 5%). Analyses of DNA data confirmed the separation of the two species; as a result, the reference database library has been supplemented with sequences of H. dominici. Furthermore, we have confirmed that this species, which is a significant indicator of sodic character, shows a positive correlation with salinity.

Making waves: The sensitivity of lakes to brownification and issues of concern in ecological status assessment

Brownification or increasing water colour is a common problem in aquatic ecosystems. It affects both physico-chemical properties and biotic communities of the impacted waters. A common view is that lakes having low background water colour are most sensitive to brownification. In this article, we show that although low-colour and high-colour lakes respond differently to brownification, the effects on biotic communities can be strong irrespective of water colour. For phytoplankton production, the effect of brownification can be positive at low colour and negative at high colour, the relative effect being strongest at high colour. For fish foraging, the disturbance per increasing unit of colour may also be highest at high-colour conditions. Additionally, the presently used classification systems mostly describe the effects of eutrophication and do not account for the effects of brownification. Studies on the whole colour range of lakes are needed and indicators used in the ecological status assessment of lakes must be developed to reveal the effects of brownification. Indicators distinguishing the effects of brownification from those of eutrophication are especially needed.