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Nutrient content in tissues of Groenlandia densa, Myriophyllum spicatum and Zannichellia palustris : an attempt to understand the intercompartmental relationships in a small stream in the Middle Atlas Mountains of Morocco

Nouri Ayoub, Bihaoui Abdesslam, Hammada Soumaya, Chillasse Lahcen

Oceanological and Hydrobiological Studies

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2024

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Vol. 53, No. 4

355--364

EN

Research has long focused on the relative importance of leaves and roots as sources of nutrient supply for macrophytes, as well as the function each stream compartment plays in their growth and development. This study aims to expand the debate on aquatic ecology and to better understand the connection between compartments in aquatic systems by highlighting the relationship observed in rivers between nutrients in macrophytes tissues, water, and sediments. We measured the concentrations of P-PO4, N-NO3 and N-NH4 in three different compartments of the Amengous stream in the Middle Atlas of Morocco. Myriophyllum spicatum (L.), Groenlandia densa (L.) Fourr. and Zannichellia palustris (L.) were selected as plant species. Our results show that even if the species coexist in the same habitat, they respond differently to nutrient richness. G. densa has a higher nutrient accumulation capacity than M. spicatum and Z. palustris and prefers the water compartment as a nutrient source. Although M. spicatum can accumulate phosphate compounds from water and sediment, ammonium is not its preferred nitrogen source. Z. palustris shows a tendency to accumulate nitrogen compounds through the roots, while it prefers the assimilation of phosphorus compounds through the leaves rather than the roots.

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Exploring the Utility of Macrophyte Metrics for Evaluating the Quality of Rivers in Morocco – Insights from the Macrophyte Biological Index for Rivers

Nouri Ayoub, Hammada Soumaya, Mhamed Khaffou, Chillasse Lahcen

Ecological Engineering & Environmental Technology

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2024

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Vol. 25, iss. 5

96--105

EN

Macrophytes not only integrate environmental conditions but also reflect the trophic state of the aquatic environment through several metrics. The lack of knowledge on the biology and ecology of aquatic plants in Moroccan rivers makes it very difficult to establish a comprehensive and effective national metric for assessing the trophic state of rivers. Indeed, the use of one of the European methods, which have been the subject of geographical intercalibration projects across different countries, particularly those in the Mediterranean region, proves necessary. Given Morocco’s geographic location within the Mediterranean Basin, Macrophyte Biological Index for Rivers (IBMR) was chosen as a method to assess Moroccan running waters. Furthermore, it allowed answering a number of questions about the usage of biological metrics based on macrophytic communities throughout Morocco. The obtained results showed that the IBMR can provide an indication of the overall trophic state of the watercourse, but with well-defined conditions, namely stable hydrological conditions with a significant richness in contributing pollution-sensitive species. Although this macrophyte index showed correlations with the parameters responsible for eutrophication phenomena, it remained less effective in the face of the downgrading parameter. Thus, the particular context of Moroccan watercourses, namely the watercourses of the Upper Oum Er-rbia basin, and the major pitfall that still lies in the knowledge of the ecology of plant groups in Moroccan running waters, can pose a problem in the application of the IBMR index, especially with regard to ubiquitous species that dominate the downstream sites of the studied rivers.

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Exploring the Bioactive Potential of Tamarix africana: Phytochemical Profiling, Antioxidant and Antibacterial Activities Assessment

Bihaoui Abdesslam, Idir Abderrazak, Nouri Ayoub, Talbi Hayat, Haddioui Abdelmajid, Hammada Soumaya

Ecological Engineering & Environmental Technology

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2024

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Vol. 25, iss. 6

188--199

EN

In Morocco, the Tamaricaceae family is represented by six species belonging to the Tamarix genus. including Tamarix africana which is utilized in traditional medicine to treat various ailments. This study aims to compare and evaluate the total polyphenol and flavonoid contents, as well as the antioxidant and antibacterial activity of Tamarix africana leaf and flower extracts obtained by Soxhlet extraction using five solvents of increasing polarity. The highest extraction yield was obtained with methanol for the leaves and flowers. Indeed, the results indicate that methanolic extracts contained the highest concentration of polyphenols and flavonoids for both organs (Polyphenols: 101.80 mg GAE/g DW in the leaf extract and 50.55 mg GAE/g DW in the flower extract. Flavonoids: 990.723 µg RE/g DW in the leaf extract and 630.84 µg RE/g DW in the flower extract). The results of antioxidant activity revealed that the aqueous extract of leaves and flowers of T. africana (IC50: 1.89 µg/mL and 3.175 µg/ mL respectively) had higher antioxidant activities than ascorbic acid. Concerning the antibacterial study, Bacillus subtilis showed resistance to the tested extracts. However, for the Citrobacter freundii strain, inhibition zones of 14 mm were recorded by the aqueous extract of flowers. On the other hand, the strong inhibition zones recorded against the Enterococcus faecalis strain, were 13 mm recorded by the leaves methanolic extract. Regarding the MIC, it is 6.25 mg/ml for the two strains. Concerning MBC, the results showed that the extracts are bacteriostatic in nature against Citrobacter freundii and Enterococcus faecalis. Thus, Tamarix africana seems to be a potential source of active molecules that could constitute a new alternative for medical and industrial use.