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Vienna, Austria

Niedermayr R.,DWS Hydro Okologie GmbH | Schagerl M.,University of Vienna
Fundamental and Applied Limnology | Year: 2010

The phytobenthos community of a carbonate headwater and its springs were studied in the Kalkalpen National Park (Austria). The investigated rivulet Almbach is located at a traditionally farmed mountain pasture. Two springs, one of them fenced in to prevent livestock access, and two more sites from the headwater were sampled from May to October 2005. Whereas diatoms dominated the fenced spring, chlorophytes reached highest biomass at the spring with livestock access. A Discriminant Analysis revealed three functions based on nitrate, phosphorus and channel width, which classified 100% of the sites correctly. Indicator taxa - regarded as highly indicative of a particular site when they are mainly found at that site and are present in a large number of its sample units - were mainly detected at the cattle-free sites. Both springs differed significantly from the rivulet sites and from each other concerning physico-chemical parameters, algal community structure, biomass and seasonal development. Canonical Correspondence Analysis was used to analyze the phytobenthos community pattern along environmental gradients. Phosphorus, benthic ash-free dry mass and pH had the highest influence on the first two axes, which explained 78 % of taxa-environmental variation. A negative impact of pasturing on the sensitive high mountain headwater system was detected because of reduced bank stability through trampling, decreased canopy cover and increased nitrogen input. These factors caused an atypical, chlorophyte- dominated phytobenthos community with both low algal diversity and evenness. © 2010 E. Schweizerbart'sche Verlagsbuchhandlung, Stuttgart, Germany. Source

Pilotto F.,University of Rome La Sapienza | Free G.,U.S. Environmental Protection Agency | Cardoso A.C.,European Commission - Joint Research Center Ispra | Wolfram G.,DWS Hydro Okologie GmbH | Solimini A.G.,University of Rome La Sapienza
Fundamental and Applied Limnology | Year: 2012

Invertebrate communities inhabiting different lake zones are expected to respond differently to natural environmental variation and anthropogenic stressors. We used multivariate statistical methods in order to quantify the effects of eutrophication and morphological pressures on the spatial structure of the invertebrate benthic communities at two depth zones (profundal and sublittoral) in subalpine lakes in Italy, Germany and Austria . In both lake zones, environmental variables related to eutrophication pressures (mid-lake total phosphorus and chlorophylla) were significant in structuring the invertebrate community (permutation test: p < 0.01). Three variables relating to morphological pressures (diversity of macrophyte growth forms, sum of pressures in the lake shore, and percentage of natural land cover within a 200 m stretch from the lake shore) were significant (permutation test: p < 0.01) in the sublittoral zone, while in the profundal zone none of the variables included in the analysis related to morphological pressures were significant in structuring the invertebrate community. Variance partitioning analysis showed that profundal communities were mainly affected by eutrophication (8.6 % of total variance; p = 0.005), while in the sublittoral zone eutrophication accounted for only 0.5 % (p = 0.04) of total variance. The effects of morphological pressures could be tracked only in the sublittoral zone, where it accounted for 0.8 % of total variance (p = 0.015). The spatial component was responsible for a large part of the total variance (58.7 % in the profundal, p = 0.005; 44.2 % in the sublittoral zone, p = 0.005) and had interactions with stressor variables in both lake zones. Therefore the analysis of spatial patterns should be included in assessment systems relating invertebrate assemblages to pressures. © 2012 E. Schweizerbart'sche Verlagsbuchhandlung, Stuttgart, Germany. Source

Adamek Z.,Academy of Sciences of the Czech Republic | Orendt C.,Orendt Hydrobiologie | Wolfram G.,DWS Hydro Okologie GmbH | Sychra J.,Masaryk University
Biologia | Year: 2010

Benthic macroinvertebrates are an important indicator of river health. However, their response upon water quality development downstream the pollution outlets considerably depends on the environmental habitat characteristics. Three successive stretches, each of them providing three different mesohabitats in stillwater (S), torrential (T) and riparian (R) zones were selected for evaluation of the impact of altered metapotamal river bed morphology (channelization) and chemical determinants of water quality on the Upper Elbe River. In downstream direction, the stretches are separated by weirs and characterized as a low polluted low modified natural stream (N), a low polluted channelized stream (C) and a channelized polluted stream (CP). Altogether, 111 benthic macroinvertebrate taxa were recorded in the Pardubice hotspot between Němčice and Přelouč. Despite different levels of stream bed and water quality degradation, micro- and mesohabitat characteristics appeared to be the most important factors determining the diversity of macrozoobenthos in riffle (substrate size structure) and in shoreline (macrophyte community composition and structure) mesohabitats. The diversity of macroinvertebrate communities was highest in riparian mesohabitats compared to stillwater and torrential ones. Saprobic indices increased in downstream direction, thus indicating the decline of water quality. © 2010 Institute of Zoology, Slovak Academy of Sciences. Source

Poikane S.,European Commission - Joint Research Center Ispra | Van Den Berg M.,Center for Water Management | Hellsten S.,Finnish Environment Institute | De Hoyos C.,Center for Hydrographic Studies | And 8 more authors.
Procedia Environmental Sciences | Year: 2011

The Water Framework Directive (WFD) has been published in 2000 and the process of its implementation has created a new paradigm in the understanding of ecological status of water bodies in Europe. The Directive explicitly requires that ecological status is assessed through the analysis of various characteristics of aquatic flora and fauna. An Intercalibration exercise is foreseen to identify and resolve significant inconsistencies between the ecological quality classifications of EU Member States to ensure that the obligation to reach good status has the same meaning throughout Europe. The results of the first Lake Intercalibration exercise (2003-2008) are the setting of reference conditions and class boundaries for phytoplankton biomass metrics for all lake intercalibration types and all geographical regions of the EU. Work on macrophyte assessment methods has been carried out in the Alpine, Central/Baltic and Northern region, while only Alpine and Mediterranean countries have succeeded to develop and harmonize phytoplankton composition assessment methods. The aim of the second phase of intercalibration (2008-2011) is to close these gaps and improve the comparability of the results in time for the second river basin management plans due in 2015. © 2011 Published by Elsevier Ltd. Source

Poikane S.,European Commission - Joint Research Center Ispra | Birk S.,University of Duisburg - Essen | Bohmer J.,Bioforum GmbH | Carvalho L.,UK Center for Ecology and Hydrology | And 16 more authors.
Ecological Indicators | Year: 2015

The Water Framework Directive is the first international legislation to require European countries to establish comparable ecological assessment schemes for their freshwaters. A key element in harmonising quality classification within and between Europe's river basins is an "Intercalibration" exercise, stipulated by the WFD, to ensure that the good status boundaries in all of the biological assessment methods correspond to similar levels of anthropogenic pressure. In this article, we provide a comprehensive overview of this international comparison, focusing on the assessment schemes developed for freshwater lakes. Out of 82 lake ecological assessment methods reported for the comparison, 62 were successfully intercalibrated and included in the EC Decision on intercalibration, with a high proportion of phytoplankton (18), macrophyte (17) and benthic fauna (13) assessment methods. All the lake assessment methods are reviewed in this article, including the results of intercalibration. Furthermore, the current gaps and way forward to reach consistent management objectives for European lakes are discussed. © 2015 The Authors. Published by Elsevier Ltd. This is an open access article under the CC BY-NC-ND. Source

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