Originalities of Willow of Salix atrocinerea Brot. in Mediterranean Europe

Abstract

Willow communities (genus Salix) occurring in Mediterranean Europe are presented, showing, through statistical treatment with multivariate cluster analysis, the separation of the different plant communities and their sintaxonomic affiliation. Six willow communities have been identified, whose formations include a set of plants with high heritage value. We highlight plants with legal protection status (Annex IV and II of the Habitats Directive-92/43/EEC), endemic, rare, and endangered species such as Salix salviifolia subsp. australis, Cheirolophus uliginosus, Euphorbia uliginosa and Leuzea longifolia. Therefore, two new willow communities are proposed for the southwest of the Iberian Peninsula. The first dominated by Salix atrocinerea, Frangulo baticae-Salicetum atrocinereae ass. nova of ribatagan distribution, under acid substrates, thermomediterranean to lower mesomediterranean, dry to sub-humid. The second, dominated by the endemic Salix salviifolia subsp. australis, Clematis flammulae-Salicetum australis distributed in the Algarve, developing on neutral-basic substrates, exclusively thermomediterranous, dry to sub-humid. In both cases, there are presented on their own floristic serial, ecology, and substitution steps. A new hygrophytic meadows was also identified dominated by Molinia caerulea subsp. arundinaceae, Cheirolopho uliginosii-Molinietum arundinaceae ass. new hoc loco, which lives on substrates rich in organic matter, exclusive to the Ribatagano Sector. Through the deepening of knowledge about the composition and dynamics of riparian vegetation, it is possible to adapt management methods to sustain and protect these important edafo-hygrophilic systems in the Mediterranean.