| Abstract | The intercalibration (IC) exercise is a key element in the implementation of the Water Framework Directive (WFD) in Europe. Its focus lies on the harmonization of national classification methods to guarantee a common understanding of "Good Ecological Status" in surface waters. This article defines reference conditions and sets class boundaries for deep (mean depth >15 m, IC lake type L-AL3) and moderately deep (mean depth 315 m, IC lake type L-AL4) Alpine lakes >0.5 km2. Data were collated from each of the five EU member states included in the Alpine Geographical Intercalibration Group (Alpine GIG: Austria, France, Germany, Italy and Slovenia).
Hydro-morphological, chemical and biological data from 161 sites (sampling stations) in 144 Alpine lakes over a period of seven decades were collated in a database. Based on a set of reference criteria, 18 L-AL3 and 13 L-AL4 reference sites were selected. Reference conditions were defined using a combined approach, based on historical, paleolimnological and monitoring data in conjunction with trophic modelling and expert judgement. Reference values and class boundaries were set for annual mean total biomass (biovolume), and then derived for annual mean chlorophyll-a using a regression between the two parameters. In order to allow for geographical differences within the Alpine GIG and to facilitate the inclusion of the broadly defined common IC types and national lake types, ranges were defined for each reference value. Range of reference values are 0.2-0.3 mg l-1 (L-AL3) and 0.5-0.7 mg l-1 (L-AL4) for total biovolume and 1.5-1.9 lg l-1 (L-AL3) and 2.7-3.3 lg l-1 (L-AL4) for chlorophyll-a. Depending on lake type and variable, the ecological quality ratios (EQR) for setting the class boundaries lie between 0.60 and 0.75 for the high/good class boundary and between 0.25 and 0.41 for the good/moderate class boundary. The response of sensitive phytoplankton taxa along a nutrient gradient and the occurrence of "undesirable conditions and secondary effects" as defined in the WFD was used to validate the class boundary values, which are thus considered to be compliant with the requirements of the WFD. |
| Authors | Wolfram G.(1, Argillier C.(2, Bortoli J.(2, Buzzi F.(3, Dalmiglio A.(3, Dokulil M.T.(1, Hoehn E.(4, Marchetto A., Martinez P.-J.(5, Morabito G., Reichmann M.(6, Remec-Rekar S.(7, Riedmüller U., Rioury C.(8, Schaumburg J.(9, Schulz L.(6, Urbanic G.(10 |
| Text | 53109 2009 10.1007/s10750 009 9875 9 ISI Web of Science WOS 000268728700005 Alpine lakes phytoplankton biomass chlorofill a reference conditions Water Framework Directive Reference conditions and WFD compliant class boundaries for phytoplankton biomass and chlorophyll a in Alpine lakes Wolfram G. 1, Argillier C. 2, Bortoli J. 2, Buzzi F. 3, Dalmiglio A. 3, Dokulil M.T. 1, Hoehn E. 4, Marchetto A., Martinez P. J. 5, Morabito G., Reichmann M. 6, Remec Rekar S. 7, Riedmuller U., Rioury C. 8, Schaumburg J. 9, Schulz L. 6, Urbanic G. 10 1 DWS Hydro Okologie GmbH, 1050 Vienna, Austria; 2 Hydrobiology Research Unit, Cemagref, 13182 Aix en Provence Cedex 5, France; 3 Dipartimento Sub Provinciale Citta di Milano, ARPA Lombardia, 20129 Milano, Italy; 4 Limnologieburo Hoehn, 79102 Freiburg, Germany; 5 DIREN Rhone Alpes, delegation de bassin Rhone Mediterranee, 69422 Lyon Cedex 03, France; 6 Karntner Institut fur Seenforschung, 9020 Klagenfurt am Worthersee, Austria; 7 Environmental Agency of the Republic of Slovenia, 1000 Ljubljana, Slovenia; 8 Ministere de lEcologie et du Developpement Durable, Grande Arche, 92055 La Defense Cedex, France; 9 Bayerisches Landesamt fur Umwelt, Referat 84 Qualitat der Seen, 82407 Wielenbach, Germany; 10 Department of Biology, Biotechnical Faculty, University of Ljubljana, 1000 Ljubljana, Slovenia The intercalibration IC exercise is a key element in the implementation of the Water Framework Directive WFD in Europe. Its focus lies on the harmonization of national classification methods to guarantee a common understanding of Good Ecological Status in surface waters. This article defines reference conditions and sets class boundaries for deep mean depth >15 m, IC lake type L AL3 and moderately deep mean depth 315 m, IC lake type L AL4 Alpine lakes >0.5 km2. Data were collated from each of the five EU member states included in the Alpine Geographical Intercalibration Group Alpine GIG Austria, France, Germany, Italy and Slovenia . Hydro morphological, chemical and biological data from 161 sites sampling stations in 144 Alpine lakes over a period of seven decades were collated in a database. Based on a set of reference criteria, 18 L AL3 and 13 L AL4 reference sites were selected. Reference conditions were defined using a combined approach, based on historical, paleolimnological and monitoring data in conjunction with trophic modelling and expert judgement. Reference values and class boundaries were set for annual mean total biomass biovolume , and then derived for annual mean chlorophyll a using a regression between the two parameters. In order to allow for geographical differences within the Alpine GIG and to facilitate the inclusion of the broadly defined common IC types and national lake types, ranges were defined for each reference value. Range of reference values are 0.2 0.3 mg l 1 L AL3 and 0.5 0.7 mg l 1 L AL4 for total biovolume and 1.5 1.9 lg l 1 L AL3 and 2.7 3.3 lg l 1 L AL4 for chlorophyll a. Depending on lake type and variable, the ecological quality ratios EQR for setting the class boundaries lie between 0.60 and 0.75 for the high/good class boundary and between 0.25 and 0.41 for the good/moderate class boundary. The response of sensitive phytoplankton taxa along a nutrient gradient and the occurrence of undesirable conditions and secondary effects as defined in the WFD was used to validate the class boundary values, which are thus considered to be compliant with the requirements of the WFD. 633 articolo pubblicato 09_Hydrobiologia_2009_Morabito.pdf Articolo in rivista Kluwer Academic Publishers 0018 8158 Hydrobiologia The Hague. Print Hydrobiologia The Hague. Print Hydrobiologia The Hague. Print Hydrobiologia. The Hague. Print Hydrobiologia Dordrecht The Hague. Print Hydrobiologia Boston The Hague. Print Hydrobiologia London The Hague. Print aldo.marchetto MARCHETTO ALDO giuseppe.morabito MORABITO GIUSEPPE TA.P04.016.004 Ecologia teorica e applicata degli ecosistemi acquatici |
