Autoecological and Synecological Resilience of Angelica heterocarpa M.J. Lloyd, Observed in the Loire Estuary (France)

Abstract

This study aims to characterize the ecology, behavior and responses of Angelica heterocarpa up to the level of the vegetation series and of the human modification of its habitats, in the Loire estuary. Original observations and an extensive bibliography review follows. Angelica heterocarpa is classified as a Sublittoral Eu-Atlantic (Franco-Atlantic endemic) taxon, living in clay-muddy estuary banks. The locus classicus of the species is from Loire River, in the area of Nantes. Its natural biotope corresponds to the oligohaline domain of the West French Atlantic estuaries. In many ways, Angelica heterocarpa is a very adaptable species. The plant develops also in epiphytic conditions and in “stand-by mode” strategy, allowing a hydrochoral dispersion. Vegetation series, Ecological, Phytosociological, Phytodynamic features and management advices are described. While the geographic distribution area is large enough not to be of concern, and the plant shows a good adaptability, the global population trend shows a huge regression linked to the destruction of habitats. Due to these threats and its endemic status, this species is considered worthy of protection, and conservation policies and in situ experimentations are being carried out.