Impact of sediment deposition on the distribution of plant formations in the neoformed zones of the Allal El Fassi dam

Abstract

This study examines the effects of sedimentation on the distribution and diversity of plant communities in urbanized areas near the Allal El Fassi dam, aiming to elucidate how sediment properties influence local biodiversity. To achieve this, we employed a comprehensive analysis of plant and soil samples from nine neoformed areas that exhibit diverse sedimentation characteristics. Our methodology included evaluating physicochemical parameters and conducting floristic assessments to reveal the variations in plant species diversity. The analysis identified two distinct categories of sediment: Group 1 (stations S6-S9) presented alkaline pH, conductivity above 40 μS/cm, and organic matter concentrations greater than 2.98 %; Group 2 (stations S1-S5) exhibited slightly alkaline pH, conductivity below 40 μS/cm, and organic matter between 1.8 % and 2.98 %. Sediment composition revealed significant macroelement concentrations, influenced by mineral content and soil management practices, impacting soil fertility and nutrient availability for plants.Floristic analysis across these areas revealed a high level of biodiversity, identifying 36 plant families and 74 species adapted to the sediment conditions. The Asteraceae family was the most abundant (25.7 %), represented by species such as Calendula arvensis, Carduus pycnocephalus, and Xanthium strumarium. Other families, including Brassicaceae (6.8 %) with Eruca vesicaria and Nasturtium officinale, and Poaceae (5.4 %) with Arundo donax and Cyanodon dactylon, further contributed to the diversity. Principal component analysis identified four species assemblages significantly influenced by soil attributes, with certain species demonstrating bioaccumulation of trace elements, underscoring their potential in soil remediation.These findings offer valuable insights for sediment manage ment and biodiversity conservation, emphasizing the critical role of sediment characteristics in supporting diverse plant communities within dam-affected regions. The study enhances our understanding of ecosystem dynamics in areas impacted by dam construction, offering guidance for sustainable ecosystem management and restoration in similar sediment-influenced environments.

Keywords

• Dams
• Trace elements
• Plant diversity
• Soil properties and sedimentation