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Effects of the herbicide metazachlor on macrophytes and ecosystem function in freshwater pond and stream mesocosms / Mohr, S. (2007)
Titre : Effects of the herbicide metazachlor on macrophytes and ecosystem function in freshwater pond and stream mesocosms Type de document : texte imprimé Auteurs : S. Mohr ; R. Berghahn ; M. Feibicke ; S. Meinecke ; T. Ottenströer ; I. Schmiedling ; R. Schmiediche ; R. Schmidt Année de publication : 2007 Article en page(s) : pp 73-84 Catégories : Ecoplanète
ECOSYSTEME ; HERBICIDE ; MACROPHYTE ; metazachlor
Résumé : The chloroacetamide metazachlor is a commonly used pre-emergent herbicide to inhibit growth of plants especially in rape culture. It occurs in surface and ground water due to spray-drift or run-off in concentrations up to 100 _x0002_gL−1. Direct and indirect effects of metazachlor on aquatic macrophytes were investigated at oligo- to mesotrophic nutrient levels employing eight stream and eight pond indoor mesocosms. Five systems of each type were dosed once with 5, 20, 80, 200 and 500 _x0002_gL−1 metazachlor and three ponds and three streams served as controls. Pronounced direct negative effects on macrophyte biomass of Potamogeton natans, Myriophyllum verticillatum and filamentous green algae as well as associated changes in water chemistry were detected in the course of the summer 2003 in both pond and stream mesocosms. Filamentous green algae dominated by Cladophora glomerata were the most sensitive organisms in both pond and stream systems with EC50 ranging from 3 (streams) to 9 (ponds) _x0002_gL−1 metazachlor. In the contaminated pond mesocosms with high toxicant concentrations (200 and 500 _x0002_gL−1), a species shift from filamentous green algae to the yellow-green alga Vaucheria spec. was detected. The herbicide effects for the different macrophyte species were partly masked by interspecific competition. No recovery of macrophytes was observed at the highest metazachlor concentrations in both pond and stream mesocosms until the end of the study after 140 and 170 days. Based on the lowest EC50 value of 4_x0002_gL−1 for total macrophyte biomass, it is argued that single exposure of aquatic macrophytes to metazachlor to nominal concentrations >5 _x0002_gL−1 is likely to have pronounced long-term effects on aquatic biota and ecosystem function.
in Aquatic toxicology > n°82 (2007) . - pp 73-84[article]Relationships between the presence of odonate species and environmental characteristics in lowland ponds of central Italy / CARCHINI, G. (2007)
Titre : Relationships between the presence of odonate species and environmental characteristics in lowland ponds of central Italy Type de document : texte imprimé Auteurs : G. CARCHINI ; Della Bella V ; Solimini AG & Bazzanti M Année de publication : 2007 Article en page(s) : pp 81-88 Catégories : Ecoplanète
MACROPHYTE ; nitrogen ; Odonata ; permanent and temporary ponds
in Annales de Limnologie - International Journal of Limnology > n°43 (2007) . - pp 81-88[article]The freshwater biota of British agricultural landscapes and their sensitivity to pesticides / Jeremy Biggs (2007)
Titre : The freshwater biota of British agricultural landscapes and their sensitivity to pesticides Type de document : texte imprimé Auteurs : Jeremy Biggs ; Penny Williams ; Mericia Whitfield ; Pascale Nicolet ; Colin Brown ; John Hollis ; Dave Arnold ; Tim Pepper Année de publication : 2007 Article en page(s) : pp 137-148 Catégories : Ecoplanète
évaluation des risques ; INVERTEBRE ; MACROPHYTE ; PESTICIDE
Résumé : This study analysed information from national and regional datasets gathered in Great Britain describing the occurrence of aquatic macroinvertebrates and macrophytes in ponds, ditches, streams, rivers and lakes, across 12 agricultural landscape classes and a 13th class comprising non-agricultural land. The study found major differences in the composition of the invertebrate faunas of running and still water. River and stream assemblages had a relatively high proportion of species (20-40%) in groups believed to be sensitive to pesticides (mayflies, stoneflies, amphipod crustaceans). The proportion of these taxa also varied across the landscape with greater numbers of pesticide-sensitive species present in streams in more acid landscape classes. Ponds, in contrast, were dominated by water beetles and water bugs and supported fewer sensitive taxa (ca. 5% of the species present). The proportion of the fauna made up by these two taxonomic groups in ponds varied little between landscape classes. Ditches were intermediate between ponds and streams in both taxonomic composition and their variability across landscape class. Invertebrate species richness and rarity values were highest in rivers and ponds with fewer species in streams and ditches. Ponds typically supported more uncommon invertebrate species than other waterbody types. Plant assemblage data showed that, except for lakes, wetland landscape types (fenlands and valleys) were generally richer in species, with more uncommon taxa, than other landscapes. Ditch floras were often outstanding in these areas. The study findings have applications and implications in areas such as the development of environmentally valid mesocosm studies and for the creation of realistic scenarios in probabilistic risk assessment.
in Agriculture, Ecosystems and Environment > n°122 (2007) . - pp 137-148[article]Séminaire Européen "Gestion et conservation des ceintures de végétation lacustre" : LIFE- Nature du programme Lac du Bourget 23,24 et 25 Octobre 2002 / Collectif (2003)
Titre : Séminaire Européen "Gestion et conservation des ceintures de végétation lacustre" : LIFE- Nature du programme Lac du Bourget 23,24 et 25 Octobre 2002 Type de document : document électronique Auteurs : Collectif Mention d'édition : Janvier 2003 Année de publication : 2003 Importance : 256 p. Note générale : Disponible en 2 exemplaires. Accompagné d'un cdrom reprenant les présentations orales.
Document biligue français/ anglais
Langues : Français (fre) Anglais (eng) Catégories : Ecoplanète
DIAGNOSTIC ; HYDROLOGIE ; LAC ; MACROPHYTE ; restauration ; rivages lacustres
Index. décimale : 22 Lacs Résumé : Session 1 : importance écologique et sociale de la végétation macrophyte.
Session 2 : statut régional et diagnostic.
Session 3 : hydrologie et management.
Session 4 : restauration du rivage lacustre.
Session 5 : expériences de management.
Session 6 : indicateurs biologiques et objectifs.
Des posters et une liste des participants complètent ce document.
Genre de document : Actes de rencontre Descripteur géographique : SAVOIE-73