Approche phytosociologique et symphytosociologique des végétations et des paysages du Bas-Vivarais (nord du Bassin méditerranéen français)

Abstract : Occupying about 1800 km², the Bas-Vivarais Region corresponds to the sedimentary part of the Ardèche department, located on the south-eastern edge of the Massif Central. Due to varied lithology and geomorphology features, to a climatic context forming part of a latitudinal mediterranean gradient, and despite an apparent homogeneity, the vegetation appears to be very diversified and original, compared to the vegetation of the rest of the Mediterranean Basin.The study of plant communities and complexes communities was undertaken following the principles of the Braun-Blanqueto-Tüxenian phytosociology and on the methodology of the French-Spanish (geo)synphytosociology. The analysis of 2.619 relevés and 388 synrelevés allows to highlight 144 syntaxa of association level among which 58 units appear new, 54 synassociations and hypogeosynassociations.The phytosociological study allows to increase the knowledge about Mediterranean vegetations and proposes a analysis framework based on synecological and structural and synchorological criteria that can be transposed to the entire Mediterranean basin.In the Bas-Vivarais, the study of the complexes (groups) of communities following the French-Spanish methodology, shows the limits of community complexes study based on a purely phytodynamic and serial approach. It obliges to come back to the fundamentals of integrated inductive landscape phytosociology, (TÜXEN 1973, 1979), that is to say the causal description of ecologically homogeneous synassociations through the demonstration of repetitive combinations of communities. Methodological recommendations are therefore proposed for the in situ delineation of communities complexes and the characterization of homogeneous units both at synecological and physiognomic levels.
Document type :
Theses
Complete list of metadatas

https://tel.archives-ouvertes.fr/tel-02280396
Contributor : Abes Star <>
Submitted on : Friday, September 6, 2019 - 3:38:05 PM
Last modification on : Friday, September 20, 2019 - 12:47:29 PM

Identifiers

  • HAL Id : tel-02280396, version 2

Citation

Guillaume Choisnet. Approche phytosociologique et symphytosociologique des végétations et des paysages du Bas-Vivarais (nord du Bassin méditerranéen français). Ecologie, Environnement. Université de Bretagne occidentale - Brest, 2019. Français. ⟨NNT : 2019BRES0008⟩. ⟨tel-02280396v2⟩

Share

Metrics

Record views

69

Files downloads

31