10 research outputs found

    Bellis prostrata Pomel (Asteraceae), a new species for Morocco

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    Investigations conducted in temporary wetlands of the coastal Meseta of W Morocco (Benslimane region) lead to the discovery of Bellis prostrata in a small endoreic temporary pool (ca. 1 ha) of the quartzitic-limestone plateau of Benslimane

    Uses and Conservation of Mediterranean temporary pools : the case study of the temporary pools of Benslimane region (western Morocco).

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    Cette thèse porte sur l'étude de la relation Homme-Mare temporaire dans la région de Benslimane. Une approche pluridisciplinaire intégrant l'écologie et la sociologie a été adoptée, afin d'apporter des réponses adaptées aux problématiques liées à ces habitats et de permettre leur développement durable. Le premier volet a pour but d'évaluer les facteurs clés déterminant la richesse de la végétation des mares de cette région. Les résultats obtenus révèlent l'influence prédominante des facteurs locaux, avec un effet significatif des facteurs régionaux et de la vulnérabilité des mares aux usages, sur l'expression de la richesse floristique. Les activités anthropiques affectent différemment la richesse en espèces Préférentielles. Le second volet se focalise sur les causes de régression des mares, en couplant l'évaluation des menaces à une enquête socio-économique. Les résultats montrent la prédominance d'une perception anthropocentrique des mares temporaires. Ce constat traduit le haut niveau de menace qui pèse sur les mares de cette région. L'évaluation de ces menaces, qui indique que 22 % des mares sont vulnérables et que 23 % sont menacées de destruction à court terme, soulignent le besoin urgent de nouvelles politiques environnementales et d'approches innovantes de gestion des mares temporaires. Enfin, le troisième volet s'intéresse à l'impact du pâturage sur la végétation des mares. Les résultats montrent que cette perturbation affecte la végétation des mares, à l'échelle régionale et locale. Ces résultats sont interprétés comme résultant de l'effet sélectif des herbivores et la tolérance différentielle des espèces aux perturbations. Au terme de cette étude, la gestion intégrée des mares apparaît comme le moyen le plus approprié pour le développement durable de cet "éco-socio-système" complexe, en conciliant développement économique et bon état écologique des ressources, et en liant les questions environnementales, économiques et sociales.This thesis focuses on the study of the relationship Man-Temporary pool. A multidisciplinary approach integrating ecology and sociology has been adopted to provide appropriate responses to the problems related to these ecosystems and to allow their sustainable development. The first section aims at evaluating the key factors determining the vegetation richness within regional pools. The obtained results reveal the predominant influence of local factors, with a significant effect of regional factors and the vulnerability of pools to use, on the expression of the vegetation. Human activities affect differently the richness in preferential pool species. The second section focuses on the major causes of the regression of pools, by coupling threats assessment and a socio-economic survey. The results point out the anthropocentric perception of pools. This translates the high level of threat concerning the temporary pools of Benslimane region. The thr eat assessment, which shows that 22 % of pools are vulnerable, and 23 % are threatened of destruction of the short term, highlights the urgent need for new environmental policies and innovative approaches of temporary pools management. Finally, the third section concerns the impact of grazing on the vegetation of temporary pools. The results demonstrate that grazing affects the vegetation of pools, both at the regional and the local scale. These results are interpreted as a result of the selective influence of herbivores, and the differential tolerance of species to disturbance. At the end of the present study, the integrated management of pools appears as the most appropriate means for the sustainable development of this complex eco-socio-system, by combining the economic development and the ecological status of resources, and by linking environmental, economic and social issues

    Unravelling the impact of anthropogenic pressure on plant communities in Mediterranean temporary ponds

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    International audienceIdentifying the respective role of environmental, landscape and management factors in explaining the patternsin community composition is an important goal in ecology. Using a set of 32 temporary ponds in northern Morocco westudied the respective importance of local (within the pond) and regional (density of ponds in landscape) factors and theimpacts of different land uses on the plant species assemblages, separating pond and terrestrial species. The mainhypotheses tested were that (1) species assemblages respond to both local and regional environmental factors, (2)anthropogenic pressure has a negative influence on the number of pond species, and that (3) human activities differ in theirimpact on pond biodiversity. The results showed that (1) local factors explain most of the variation in plant communitycomposition, and (2) land use impacts the communities through changing local environmental conditions, leading to a lossof typical pond species. Aside from recreation, all other activities (grazing, drainage, agriculture and partial urbanisation)significantly reduced the number of pond species. The conservation strategy for rare pond species should focus onmaintaining networks of oligotrophic ponds, while allowing only low-impact activities

    Plant community patterns in Moroccan temporary ponds along latitudinal and anthropogenic disturbance gradients

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    International audienceBackground: Temporary ponds, an abundant habitat in the Maghreb region and notably in Morocco, have a high conservation value. However, they are mainly known from the north of the country.Aims: The aim of this work was to characterise the vegetation of Moroccan temporary ponds along a combined gradient of latitude and anthropogenic pressure.Methods: Eighty-five ponds distributed along a north–south gradient of 750 km were sampled. For each pond, all vegetation was surveyed (flooded and dry parts) and the local abiotic characteristics were measured during two successive hydrological cycles. The prevailing anthropogenic pressures were also identified and were attributed an impact score.Results: Eighty-one characteristic pond species (including 17 rare species) were recorded, with several new distribution data in the southern part of the latitudinal gradient. Plant communities were related to climatic and anthropogenic factors, but mostly to local factors, such as maximum water depth and soil pH. The northern ponds (wettest macroclimate) were rich in characteristic species and rare species, while the southern (driest macroclimate) ponds were more species poor.Conclusions: In addition to the direct impact of increasing human activity, a further reduction of the floristic richness of temporary ponds is expected due to climatic changes. This is particularly the case for characteristic species which have a high conservation value

    Bellis prostrata Pomel (Asteraceae), a new species for Morocco. Contribuciones a la flora vascular de Marruecos: Bellis prostrata Pomel (Asteraceae), una nueva especie para Marruecos

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    Bellis prostrata Pomel (Asteraceae), una nueva especie para Marruecos Key words.North Africa, endemic species, conservation, temporary wetland. Palabras clave. Norte de África, especie endémica, conservación, humedales temporales
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