title: [Temporal variations of physicochemical and microbiological parameters in three freshwater ecosystems (southeastern France) invaded by Ludwigia spp].
abstract: In France, two amphibious hydrophytes of alien Ludwigia (Onagraceae) have for about the past twenty years been causing serious ecological and economic problems: L. peploides (Kunth) Raven et L. grandiflora (Michaux) Greuter & Burdet. This bacteriological and physicochemical study, focused on three different Mediterranean aquatic ecosystems, reveals, for the first time, a direct negative impact of these American invaders. During summer, while plant growth is intensive, and the appearance in the water column of anoxic conditions and production of toxic compounds may be observed, notably in L. grandiflora stands. The toxicity is linked to a proliferation of sulphate-reducing bacteria producing sulphides that are very harmful for aquatic organisms.
authors.affiliation: Institut Méditerranéen d'Ecologie et de Paléoécologie, UMR 6116, Faculté des Sciences et Techniques de Saint-Jérôme, Université Paul-Cézanne, 13397 Marseille cedex 20, France. sophie.dandelot@netcourrier.com
authors.forename: Sophie
authors.initials: S
authors.lastname: Dandelot
authors.forename: Robert
authors.initials: R
authors.lastname: Matheron
authors.forename: Jean
authors.initials: J
authors.lastname: Le Petit
authors.forename: Régine
authors.initials: R
authors.lastname: Verlaque
authors.forename: Arlette
authors.initials: A
authors.lastname: Cazaubon
mesh_terms: D001419:Bacteria / Q000378:metabolism; D055598:Chemical Phenomena; D002627:Chemistry, Physical; D017753:Ecosystem; D005602:France; D005618:Fresh Water; D029594:Onagraceae / Q000737:chemistry / Q000502:physiology*; D012621:Seasons; D013431:Sulfates / Q000378:metabolism; D014871:Water Microbiology
chemical_list: D013431:Sulfates