Contribution to the study of plant communities dominated by Ailanthus altissima (Mill.) Swingle, in the Eastern Romania (Moldavia)

Abstract

In this paper, we aimed to analyze the structure, ecology and syntaxonomy of the communities dominated by Ailanthus altissima, in the Eastern Romania (Moldavia). This study has been achieved during our research on alien plants, conducted in 2009-2010. A number of 20 vegetation relevés have been carried out according to the Braun-Blanquet's methodology, in the spontaneous communities of Ailanthus altissima. The investigations led to the description of a new plant association (Balloto nigrae- Ailanthetum altissimae ass. nova). It is subordinated to the alliance Balloto nigrae- Robinion Jurko ex Hadač & Sofron 1980, order Chelidonio-Robinietalia Jurko ex Hadač & Sofron 1980, class Robinietea Jurko ex Hadač & Sofron 1980. Recognition species are Ballota nigra and Ailanthus altissima. Besides these, among the characteristic species of higher syntaxa (alliance, order, class), the following species stand out: Bromus sterilis (constant), Urtica dioica and Galium aparine (sub-constant). The stands are found on sunny lands, on roadsides, railway embankments, railway stations, steep slopes, ravines, abandoned fields, abandoned orchards or vineyards on terraces, ruderal lands, sandy lands, degraded pastures, or on the edge of Robinia pseudacacia plantations. They are situated between 38 and 265 m a.s.l. In ecological terms, the association Balloto nigrae- Ailanthetum altissimae includes heliophilous (sub-heliophilous), moderate thermophilous, xero-mesophilous, neutrophilous and moderate nitrophilous phytocoenoses. The results are discussed against the background of similar investigations of anthropogenic woody plant communities carried out by others authors.