The ecological and economic impact of invasive species is perceived at all levels, locally, regionally and globally. The ecological invasion is considered the second serious threat to natural habitats by their fragmentation and loss. Plant invasion is a difficult phenomenon to control if the processes and factors involved are not sufficiently known. By discovering the determinants of invasion success at any scale, and the efforts to control them, we help the increase of the effectiveness in controlling this phenomenon. Ailanthus altissima, invasive species of trees, was regarded as "the most serious threat to natural areas", which can cause major losses of biodiversity and can eliminate native species occupying the same ecological niche. When disappearing species are of economic interest, loss of biodiversity is accompanied by substantial economic loss as well. The aim of this work was to study a habitat in Romania that suffered from an influx of Ailanthus altissima, to determine how widespread it is, which are the areas occupied by it and the consequences on biodiversity. The study was conducted in an area of the Natural Park Porțile de Fier namely in Moldova Nouă - Berzasca. Direct observations were made on species Ailanthus altissima, its spread was recorded in the study area Moldova Nouă – Berzasca, as well as tree height and diameter. The research conducted in the field has revealed the presence of the specie both in clusters, alignments and isolated specimens (solitary) on the Danube and the base of the slopes. This is explained by the fact that the species is favoured by the anthropogenic intervention in the natural ecosystems and the current climate changes. Besides its multiplication and natural spread, the species has become more present as a result of anthropogenic activity. Our studies have demonstrated the need for further monitoring to track progress and species spreading, as well as the need to start eradication actions to stop this invasion as the main threat to the biodiversity of the area.

Ailanthus altissima, spread, impact, new areal

Presentation: oral