Interest of the Characeae as bioindicators of water quality: the case of wetlands in Numidia (NE Algeria)

Characeae surveys and water physico-chemical studies have been performed during four years (2007-2011) on 41 wetlands of Numidia (NE Algeria). Among the 12 species inventoried in the region, four are rare in North Africa and one, Nitella batrachosperma, is new for Algeria. Comparison between Characeae communities and phosphate contents shows that (1) Characeae have nearly disappeared from habitats that contain high levels of orthophosphates (> 780 μg.l-1), (2) three species of Chara (C. globularis, C. gymnophylla and C. vulgaris) characterize medium-polluted habitats (213-780 μg.l-1), where they are often present as discontinuous populations, and (3) the Nitella (N. opaca and N. translucens) are good indicators of low water pollution ( 780 μg.l-1), (2) trois espèces de Chara (C. globularis, C. gymnophylla et C. vulgaris) caractérisent les milieux moyennement pollués (213-780 μg.l-1) où elles sont souvent présentes sous forme de populations discontinues et (3) les Nitella (N. opaca et N. translucens) sont de bons indicateurs de faible pollution de l’eau (< 70 μg.l-1). En complément de la simple présence d’une espèce, l’état physiologique des plantes est à prendre en considération pour indiquer une population saine

Intérêt des Characeae comme bioindicateurs de la qualité des eaux : le cas des zones humides de Numidie (Nord-Est algérien)

Interest of the Characeae as bioindicators of water quality : the case of wetlands in Numidia (NE Algeria). Characeae surveys and water physico-chemical studies have been performed during four years (2007-2011) on 41 wetlands of Numidia (NE Algeria). Among the 12 species inventoried in the region, four are rare in North Africa and one, Nitella batrachosperma, is new for Algeria. Comparison between Characeae communities and phosphate contents shows that (1) Characeae have nearly disappeared from habitats that contain high levels of orthophosphates (> 780 μg. l-1), (2) three species of Chara (C. globularis, C. gymnophylla and C. vulgaris) characterize medium-polluted habitats (213-780 μg. l-1), where they are often present as discontinuous populations, and (3) the Nitella (N. opaca and N. translucens) are good indicators of low water pollution ( 780 μg. l-1), (2) trois espèces de Chara (C. globularis, C. gymnophylla et C. vulgaris) caractérisent les milieux moyennement pollués (213-780 μg. l-1) où elles sont souvent présentes sous forme de populations discontinues et (3) les Nitella (N. opaca et N. translucens) sont de bons indicateurs de faible pollution de l’eau (< 70 μg. l-1). En complément de la simple présence d’une espèce, l’état physiologique des plantes est à prendre en considération pour indiquer une population saine.Zouaïdia Hanene, Bélair Gérard de, Benslama Mohamed, Soulie-Marsche Ingeborg, Muller Serge. Intérêt des Characeae comme bioindicateurs de la qualité des eaux : le cas des zones humides de Numidie (Nord-Est algérien). In: Revue d'Écologie (La Terre et La Vie), tome 70, n°2, 2015. pp. 121-133

Intérêt des Characeae comme bio-indicateurs de pollution des eaux : le cas des zones humides de Numidie (Nord-Est algérien)

International audienceInterest of the Characeae as bioindicators of water quality: the case of wetlands in Numidia (NEAlgeria)–Characeae surveys and water physico-chemical studies have been performed during four years (2007-2011) on 41 wetlands of Numidia (NE Algeria). Among the 12 species inventoried in the region, four are rare in North Africa and one, Nitella batrachosperma,is new for Algeria. Comparison between Characeae communities and phosphate contents shows that (1) Characeae have nearly disappeared from habitats that contain high levels of orthophosphates (> 780 μg.l-1), (2) three species of Chara (C. globularis, C. gymnophyllaand C. vulgaris) characterize medium-polluted habitats (213-780 μg.l-1), where they are often present as discontinuous populations, and (3) the Nitella (N. opacaand N. translucens) are good indicators of low water pollution ( 780 μg.l-1), (2) trois espèces de Chara (C. globularis, C. gymnophyllaet C. vulgaris) caractérisent les milieux moyennement pollués (213-780 μg.l-1) où elles sont souvent présentes sous forme de populations discontinues et (3) les Nitella (N. opacaet N. translucens) sont de bons indicateurs de faible pollution de l’eau (< 70 μg.l-1). En complément de la simple présence d’une espèce, l’état physiologique des plantes est à prendre en considération pour indiquer une population sain

Diversity and Distribution of Characeae in the Maghreb (Algeria, Morocco, Tunisia)

International audienceCharaceae are macroscopic green algae present in the Maghreb (Morocco, Algeria, Tunisia) that are known since the 19th century works of Desfontaines (1800) and Braun (1868). Feldmann (1946) published the first regional synthesis, and this study provides a new Maghreb-wide synthesis of all collections made since 1784 (570 observations distributed over 464 sites). Each of the 31 reported species is described in detail with its diagnostic features, ecology and distribution in the three Maghrebian countries. Distribution maps distinguish between the three collection periods: 1780–1939, 1940–1979, and 1980–2016. An illustrated key is provided to help botanists working in the Maghreb to identify the taxa. From a biogeographical perspective, the Characean flora of the Maghreb is dominated by elements originating from northern (European) countries (61.3%) that include regionally very rare species such as Chara strigosa and C. tomentosa. The Mediterranean-Atlantic element is also well represented (32.3%), with some Mediterranean endemics (Chara imperfecta, C. oedophylla, C. vulgaris var. gymnophylla). Finally, two taxa that have an affinity for tropical conditions (Chara zeylanica and Lamprothamnium succinctum) extend to the southern Sahara. In North Africa, 14 species (7 Chara, 2 Lamprothamnium, 4 Nitella and 1 Sphaerochara) are threatened and raise issues about their conservation; three of these are particularly endangered: Chara imperfecta, C. oedophylla and Lamprothamnium papulosum