scholarly journals Temporal changes of aquatic macrophytes vegetation in a Iowland groundwater feed eutrophic course (Klátovské rameno, Slovakia)

2011 ◽  
Vol 76 (2) ◽  
pp. 141-150 ◽  
Author(s):  
Helena Oťahel'ová ◽  
Richard Hrivnák ◽  
Milan Valachovič ◽  
Georg A. Janauer

Klátovské rameno is the lowland slow-flowing groundwater feed eutrophic tributary of the Malý Dunaj River (Danube Plain), where our study of temporal changes of aquatic macrophytes vegetation was realised in 1999 and 2005. For survey of aquatic vascular macrophytes the Kohler’s method (Janauer 2003) was used, which is compliant with European standard EN 14184. Altogether 35 aquatic macrophyte species were recorded during the survey. Nuphar lutea persisted as the most dominant species in 1996 and 2005. Species diversity increased slightly after the nine years: ten species immigrated to the watercourse. The changes in species abundance have shown weak differences, however the abundance of Sparganium emersum has increased markedly. Alien species Elodea canadensis and both S. emersum and Hydrocharis morsus-ranae significantly enlarged their distribution in the stream. The ecological quality of the river, based on the aquatic macrophytes assessment criteria, was slightly impaired after nine years, but still 90% of its studied course has a high or good ecological status.

2009 ◽  
Vol 69 (1) ◽  
pp. 101-108 ◽  
Author(s):  
EB. Pacheco ◽  
CJ. Da-Silva

On the left bank of the Cuibá River, one of the main tributaries of the Pantanal in Mato Grosso, are located the Chacororé and Sinhá Mariana Lakes and the Mutum River, the littoral regions of which are covered with aquatic macrophytes, dominated by the species Eichhornia crassipes and Eichhornia azurea. To examine the ichthyofauna associated with this vegetation, in the year 2003, 3510 fish were collected, distributed among 83 species, and the limnological variables verified near the macrophyte stands where they were sampled. The most abundant and richest order was the Characiformes, followed by the Gymnotiformes and Siluriformes. Analysis of similarity showed a very low, or null, index that the limnological conditions and morphology of the aquatic macrophyte species provide habitat sufficiently homogeneous to give. The limnological conditions and morphology of the aquatic macrophyte species provide a sufficient habitat heterogeneity to give very low, or null, index values. Thus, environmental conservation measures should be more effective in promoting the conservation of the species, given the high levels of biological diversity found in the habitats studied.


2015 ◽  
Vol 38 (1) ◽  
pp. 59-69
Author(s):  
A. Ruiz–García ◽  
◽  
M. Ferreras-Romero ◽  

In compliance with the European Water Framework Directive, member states have had to develop a method to assess the quality of aquatic ecosystems by comparing the current situation regarding near–natural reference conditions for each river type. In 2008, the Spanish Ministry of Environment approved the Order of Water Planning Statement. This statement sets out reference conditions and ecological status class change limits for the different types of rivers in Spain for which sufficient data are available. In the presentstudy, we established reference conditions and quality class thresholds for streams classified as wet Betic mountain rivers from 24 reaches of streams located in the Los Alcornocales natural park, using two qualitative indices based on macroinvertebrates (IBMWP and IMMi–L). The results for the IBMWP index indicate that from the standpoint of management of the ecological state, the watercourses studied show more affinity with the types of the Spanish Atlantic siliceous slope than with those of the Mediterranean siliceous slope when we consider EQR values. Considering the threshold values, the index resembles siliceous low Mediterranean mountain rivers (type 8). However, the EQR values do not match those calculated in this study. These results suggest that it is necessary to use an index adapted to the characteristics of these watercourses. Application of the quality criteria contained in the Guadalete–Barbate and Mediterranean–Andalusian Basin Plans to the management of these waterways is discussed, because it is unlikely that they ensure the maintenance of good ecological status. We thus propose a new calibration of the IBMWP index that ensures the maintenance of good environmental status of watercourses in this natural area, and the use of the IMMi–L index as an effective management tool. However, as our study area represents only a part of the wet headwaters in the southern Iberian peninsula, analysis of other basin types is necessary to complete such information.


2020 ◽  
Author(s):  
Carlotta Valerio ◽  
Alberto Garrido ◽  
Gonzalo Martinez-Muñoz ◽  
Lucia De Stefano

<p>Freshwater ecosystems are threatened by multiple anthropic pressures. Understanding the effect of pressures on the ecological status is essential for the design of effective policy measures but can be challenging from a methodological point of view. In this study we propose to capture these complex relations by means of a machine learning model that predicts the ecological response of surface water bodies to several anthropic stressors. The model was applied to the Spanish stretch of the Tagus River Basin. The performance of two machine learning algorithms -Random Forest (RF) and Boosted Regression Trees (BRT) - was compared. The response variables in the model were the biotic quality indices of macroinvertebrates (Iberian Biomonitoring Working Party) and diatoms (Indice de Polluosensibilité Spécifique). The stressors used as explanatory variables belong to the following categories: physicochemical water quality, land use, alteration of the hydrological regime and hydromorphological degradation. Variables describing the natural environmental variability were also included. According to the coefficient of determination, the root mean square error and the mean absolute error, the RF algorithm has the best explanatory power for both biotic indices. The categories of land cover in the upstream catchment area, the nutrient concentrations and the elevation of the water body are ranked as the main features at play in determining the quality of biological communities. Among the hydromorphological elements, the alteration of the riparian forest (expressed by the Riparian Forest Quality Index) is the most relevant feature, while the hydrological alteration does not seem to influence significantly the value of the biotic indices. Our model was used to identify potential policy measures aimed at improving the biological quality of surface water bodies in the most critical areas of the basin. Specifically, the biotic quality indices were modelled imposing the maximum concentration of nutrients that the Spanish legislation prescribes to ensure a good ecological status. According to our model, the nutrient thresholds set by the Spanish legislation are insufficient to ensure values of biological indicators consistent with the good ecological status in the entire basin. We tested several scenarios of more restrictive nutrient concentrations and values of hydromorphological quality to explore the conditions required to achieve the good ecological status. The predicted percentage of water bodies in good status increases when a high  Riparian Forest Quality Index is set, confirming the importance of combining physico-chemical and hydromorphological improvements in order to ameliorate the status of freshwater ecosystems. </p>


Biologia ◽  
2006 ◽  
Vol 61 (4) ◽  
Author(s):  
Richard Hrivnák ◽  
Helena Oťahel’ová ◽  
Ivan Jarolímek

AbstractDistribution and plant mass of aquatic macrophytes, and their relation to environmental conditions was studied in the submontane-colline Slatina river in 2004. Diversity of macrophytes was low, only 8 vascular plants, 3 mosses and group Algae filamentosae were found. Myriophyllum spicatum is dominant species, Fontinalis antipyretica, Rhynchostegium riparioides and Algae filamentosae are frequent. Interactions between flow class, bed material, depth of water and the first three mentioned macrophytes, as well as Jungermannia leiantha were detected. Sparganium erectum prefers more antrophogenic conditions and Myriophyllum spicatum prefers the light. According to cluster analysis, three distinct and ecologically well separated parts of the river were identified. Based on Reference index, poor ecological status for the studied part of the Slatina river was estimated.


Author(s):  
Bogusław Szulc ◽  
Katarzyna Szulc

AbstractThe main aim of this study was to assess the usefulness of the Biological Diatom Index (BDI) (Lenoir & Coste 1996) for the estimation of water quality in the central section of the Pilica River, located in central Poland in Łódź province. The BDI has never been used before to monitor Polish surface waters. An analysis of the correlations between the values of the BDI and selected physico-chemical parameters was performed, as was an assessment of water quality using the BDI. On the basis of value ranges proposed by Descy and Ector (1996), a good ecological status in the Pilica River was obtained, but this did not correspond with the results achieved from the physico-chemical analysis. This study proposes new value ranges for the BDI. With these new values, the ecological state of the Pilica River changed from good to moderate, which corresponded with the physico-chemical analysis of the water. The new, proposed value ranges for the BDI assess more precisely the quality of water in lowland Polish rivers.


Botanica ◽  
2019 ◽  
Vol 25 (2) ◽  
pp. 167-175
Author(s):  
Angelina Stenina ◽  
Irina Steryagova

AbstractThe composition of diatom assemblages of epilithon, epiphython and epipelon in the Shchugor River was presented. Biofoulings of rocky substrates, macrophytes, filamentous algae and samples from the surface of bottom sediments were studied. The diatom assemblages had a diverse composition and included 218 species with varieties and forms from 60 genera, 27 families and 12 orders. The order Naviculales (56 taxa) and the family Fragilariaceae (39 taxa) played a major role. The genera Gomphonema (17 taxa), Nitzschia (16), Navicula (14), Eunotia (14) were dominant by the species abundance. The identified diatoms were mostly epiphytes, indifferent to salinity and alkaliphilous species, clean water indicators. The most common community in the river was epilithon, whereas epiphyton distinguished by the most diverse composition. The epipelon was poorly developed, having the lowest number of diatom taxa.Dominant, subdominant, accompanying species of the diatoms were very similar in different phytobenthos groups, the Sørensen-Czekanowski coefficients varied from 0.70 to 0.81. The dominant species were Achnanthidium minutissimum, Encyonema minutum, Fragilaria gracilis, Gomphonema exilissimum, G. ventricosum, Hannaea arcus, Meridion circulare. The sub-dominant species were Cocconeis placentula, Nitzschia fonticola, Ulnaria ulna and Staurosirella pinnata. Based on the Berger-Parker and Simpson variety indices, the occurrence of taxa in the genera and families in the epiphyton was more uniform. The assessment of benthic diatoms demonstrated that the Shchugor River is a typical mid-mountain river. Diatom communities of epilithon, epiphython and epipelon can be used for the monitoring of ecological status of the river.


2011 ◽  
Vol 9 (1) ◽  
pp. 37 ◽  
Author(s):  
Salvador Del Saz Salazar ◽  
Francesc Hernández Sancho ◽  
Ramón Sala Garrido

The main aim of the European Water Frame Directive is to achieve the good ecological status in all European waters by 2015 with a combined approach of different measures. In this study, two stated preference methods –contingent valuation and contingent ranking– have been applied to obtain the economic value of a hypothetical improvement of the water quality of a river. The comparison of both methods shows that contingent ranking yields higher values than contingent valuation, as found in previous literature. Lastly, the estimated values are aggregated in order to obtain the social benefits that steam from this environmental improvement.


2021 ◽  
Vol 43 ◽  
pp. e50542
Author(s):  
Eliélton da Silva Araújo ◽  
Jean Ricardo Simões Vitule ◽  
Andre Andrian Padial

Describing and understanding distribution of species in natural ecosystems is the first step to establish conservation efforts. In aquatic habitats, macrophytes play a central role in promoting biodiversity and ecosystem functioning. This study aimed to create the first checklist of aquatic macrophyte species occurring in the Guaraguaçu river, the largest river in Paraná State coast, Brazil. Species herborized, identified and incorporated into the Herbarium collection of the Universidade Federal do Paraná. A total of 47 species were registered corresponding to 37 genera and 29 botanical families; Cyperaceae and Poaceae were the most representative families. In addition, the wide invasion of the non-native species Urochloa arrecta (Hack. ex T. Durand & Schinz) Morrone & Zuloaga was registered and the presence of the floating-leaved non-native species Nymphaea caerulea Savugny was recorded. Even so, the inventory shows a noteworthy richness of aquatic macrophytes species in the Guaraguaçu river, and it is clear macrophyte species reflect a gradient of anthropic impact and salinity in this tidal estuarine river. Our study contributes to the creation of public policies to aid in the protection of this river that represents a central site for biological conservation efforts, yet is constantly threatened by anthropic activities.


2021 ◽  
Author(s):  
Milton Omar Cordova Neyra ◽  
Josiane Fernandes Keffer ◽  
Dienefe Rafaela Giacoppini ◽  
Vali Joana Pott ◽  
Arnildo Pott ◽  
...  

Abstract Southern Amazonia potentially harbors a wide diversity of aquatic macrophyte species because of its diverse wetland habitats and location in the Amazon-Cerrado transition zone, the two largest biogeographic domains in South America. We inventoried the taxonomic diversity of aquatic macrophytes in the region, including endemism, habitats, species life forms, and floristic comparisons with other Brazilian regions. We found a high number of species of aquatic macrophytes for the southern Amazon region, comparable to extensive inventories in larger areas in southern, northeastern, and northern regions of Brazil. We recorded 688 species of aquatic macrophytes in 299 genera and 95 families, of which 66 species are new records, 89 endemic, and 5 exclusive to Brazilian Amazonia. We present new records of aquatic macrophyte species, together with their degree of endemism and occurrence restricted to the region. The macrophyte species list of southern Amazonia showed 60% similarity to inventories in the Xingu basin and in northern Brazil. This high diversity of aquatic macrophytes in the Southern Amazonia, with endemic species and others with restricted ranges, emphasizes the importance of conserving wetlands and vegetation types where they grow in the region.


Author(s):  
Elena GAVRILESCU ◽  
Gilda Diana BUZATU

In Dolj County there are a number of lakes that are particularly important, because they have a large quantity of water, some of them originating from hydrotechnical accumulations, and other from natural waters. In the present study, it was performed the monitoring of the water quality of the lakes in Dolj County, in the year of 2012, namely: Victoria - Geormane, Bistreţ and Caraula. The ecological conditions of the natural and artificial lakes was established based on the state of acidification, of the oxygen regime (dissolved oxygen, biochemical oxygen demand and chemical oxygen demand), the degree of eutrophication (biogenic substances, phytoplankton biomass and chlorophyll “a”) and also based on transparency. The water samples were taken from three points: tail, middle and upstream of the lake and were analyzed using high performance equipment, namely: pH-meter, spectrophotometer DR 2010, Sechi disc, BOD5 system. In terms of the degree of eutrophication, the water from the studied lakes belongs to the third category of water quality. Geormane is a natural lake which has a very good ecological status, except regarding the eutrophication, which is considerably visible. Bistret lake has a good environmental status and is visible eutrophic. Caraula lake’s water belongs to the third category of water quality, being heavily eutrophic.


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