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Accueil du site → Doctorat → Norvège → Endemic Mimosa L. species (Fabaceae - Mimosoideae) of the Tehuacan-Cuicatlan Valley, Mexico : Biology, mycorrhiza and use

Norges Landbrukshogskole (2002)

Endemic Mimosa L. species (Fabaceae - Mimosoideae) of the Tehuacan-Cuicatlan Valley, Mexico : Biology, mycorrhiza and use

Camargo-Ricalde, Sara Lucia

Titre : Endemic Mimosa L. species (Fabaceae - Mimosoideae) of the Tehuacan-Cuicatlan Valley, Mexico : Biology, mycorrhiza and use

Auteur : Camargo-Ricalde, Sara Lucia

Université de soutenance : Norges Landbrukshogskole (Norway)

Grade : Dr.Scient. 2002

Résumé
The Tehuacán-Cuicatlán Valley is a semiarid region located in south-central Mexico. It possesses high plant diversity (ca. 3000 species) and endemism (30% of the species) ; however, ecological degradation is high. There is thus need to ecologically restore the Valley. The aim of this project was to study the biology, including the mycorrhizal symbiosis, and local uses of seven endemic Mimosa species (Fabaceae-Mimosoideae), in order to assess the potential of usage of Mimosa species in biodiversity and soil conservation strategies. Mimosa species are dominant/codominant elements within the arid tropical scrub and the ecotone between the tropical deciduous forest and the oak forest, pointing to the replacement of both vegetation types by a thorny scrub. Within their communities, Mimosa species can create "resource islands" not only rich in nutrients (e.g. OM, P, Ca, Mg) but also in arbuscular mycorrhizal (AM) fungal spores. Mycorrhizal Mimosa seedlings showed a higher total dry weight and shoot phosphorus content than non-mycorrhizal seedlings. In the laboratory, the optimal temperature for seed germination was established at 24°C and the temperature with fastest germination at 25°C, reaching all the species 100% of seed germination. All the seeds were scarified. Furthermore, local people use the 15 Mimosa species that occur in the Valley ; most of the species are used as fodder (45%) and fuel (31%), living fences (14%) and construction of fences and shelters for animals (7%), while only one species has a medicinal use. Overall of results point to the feasibility of using Mimosa species for biodiversity and soil conservation strategies, and for the improvement of local agrosilvopastoral systems practiced within the Valley. Multipurpose native shrubs and trees, particularly those that can create resource islands and fix nitrogen, should be of great interest in revegetation programs of arid and semiarid ecosystems.

Mots clés : Ecology, Mimosa, Mexico, Tehuacan-Cuicatlan Valley, Fabaceae, Mycorrhiza, Biological sciences

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Page publiée le 6 février 2015, mise à jour le 30 janvier 2017