Analyse de la Flore des Alpes. 5: Milieux et Phytosociologie

Abstract

Last in a series, this paper concludes the statistical analysis of the data published in «Flora alpina», treating that which concerns habitats and phytosociology. Expressed as percentages, the results concerning the flora are envisaged globally, by vegetation belt, by administrative division, by floristic contingent, by family, by genus and by biological form. More than 81% of endemics are found in rocky habitats, a proportion that increases with altitude, from 39% to 97% between the colline and the nival belts. Very stenoecious, 27% of the endemic taxa are exclusive of one of the major habitats, while this percentage drops to 16% among non-endemic indigenous taxa. Xenophytes are very nitrophilous: 95% of them are present in these, often anthropogenic, habitats and more than 38% are exclusive of them. Phytosociology confirms the stenoecity of endemics, as well as most of the other trends that are strongly correlated but not parallel. Cartographic patterns of four sub-alliances endemic to the Alps are provided: Physoplexido-Potentillenion, Saxifragenion lingulatae, Saxifragenion pedemontanae and Caricenion austroalpinae. The presence of many endemic taxa in these syntaxa, some narrowly stenoecious, justifies their phytosociological individualization.

Short-term signals of climate change in Italian summit vegetation: observations at two GLORIA sites

“…High mountain areas are hotspots of plant diversity and, in Europe, they host approximately 20% of the native flora (Médail & Quézel 1999;Aeschimann et al 2013). This high plant diversity is related to a rich mosaic of different habitats above the forest line and to the presence of dispersal barriers between mountain ranges that facilitated speciation processes (Körner 1995).…”