First syntaxonomical contribution to the invasive Ailanthus altissima (Mill.) Swingle forest communities at its southern limit in Europe

Abstract

Ailanthus altissima (tree of heaven), an invasive alien tree native to China, has become invasive all over the world and in Italy is present in all the administrative regions where it can form dense forest communities. Although there are several ecological studies on this species there is a lack of floristic-vegetational data for southern-Europe. The study presents the results of a floristic vegetational study on A. altissima forest communities of central Italy that aims to highlight the possible floristic-vegetational autonomy of these coenoses. The results have allowed the characterization of A. altissima coenoses at the ecological, biogeographic, syntaxonomic and landscape levels. These represent first A. altissima syntaxa described for the Italian peninsula and for southern-Europe. We propose two new sub-Mediterranean and Mediterranean associations comprised in the recently described alliance Lauro nobilis-Robinion pseudoaciae, in the Chelidonio-Robinietalia order and the Robinietea class: Asparago acutifolii-Ailanthetum altissimae: forest community with stratified structure and high canopy density on the warmer slopes of the hills in dry soil conditions and low anthropic disturbance and Aro italici-Ailanthetum altissimae: paucispecific forest communities with a monolayered structure typically found in agricultural, and peri-urban areas on pelitic, alluvial silty-sandy substrates, in conditions of edaphic humidity and high anthropogenic disturbance. The comparison with literature data highlights the autonomy of these associations of the sub-Mediterranean and Mediterranean alliance Lauro nobilis-Robinion pseudoacaciae alliance from the Balloto nigrae-Ailanthetum altissimae association of the Central and SE-European Balloto nigrae-Robinion pseudoacaciae alliance.

Anthropogenic Dusts Influence Leaf Anatomical and Eco-Physiological Traits of Black Locust (Robinia pseudoacacia L.) Growing on Vesuvius Volcano

“…The study was conducted on Robinia pseudoacacia L., a native tree species from North America, which has a pioneer characteristic that makes it a threat to native woody species [32]. Its leaves are characterized by a paraheliotropic movement which can act as a photoprotective strategy [25].…”

Vegetation and Annex I habitats of a suburban river in southern Tuscany (central Italy): remnants of plant diversity or need for restoration?

“…The herbaceous layer is rich in nitrophilous/ruderal annual and perennial species (Anisantha sterilis, Cichorium intybus, Elymus repens, Lamium maculatum, Urtica dioica), highlighting a heavy and frequent anthropic disturbance. The collected data allow classifying these communities in the alliance Lauro nobilis-Robinion pseudoacaciae, which includes several associations of A. altissima-dominated woods (Montecchiari et al, 2020). Arrigoni, 1997 (Table 24, Supplementary material) Most of the wood communities developing along the slopes and in small plains around the Bestina river are dominated by the Northern American invasive tree Robinia pseudoacacia, which replaces native meso-hygrophilous oak woods on alluvial or colluvial deposits, on damp soils rich in organic matter.…”