Autori: Fenesi, A., Ruprecht, E., Vincze, E.

Editorial: Rákosy, L., Momeu, L., Presa Universitară Clujeană, Cluj-Napoca, Neobiota din România, p.50-65, 2009.

Rezumat:

Biological invasion is one of the main ecological consequences of global changes. Among the large number of neophytes introduced into Romania, a few plant species are spreading aggressively, replacing native flora, reducing local diversity, driving rare native species to extinction, changing ecosystem properties and causing economic damages. Invasion ecology, one of the most rapidly developing branches of ecology, deals with three main topics: invasiveness, invasibility and impact. The same as other countries in the Carpathian Basin, Romania is characterized by an increasing number and impact of bioinvasions, which could be explained by the radically transformed land-use after the political changes in 1989. In spite of this fact there are only a few studies dealing with these problems. By this paper we want to fill this gap by giving a list and short descriptions about the most dangerous invasive plant species in Romania, describing the most affected and threatened habitats, where these species occur, and two possibilities of surveying the distribution and assessing the spreading phase of these species. Data about the occurrence, abundance, and habitat type of twenty-one non-indigenous species were collected from historical sources and recent field observations in order to reconstruct their past distribution, and possible ways and rate of spreading. Furthermore, systematic field-surveys were carried out along rivers to specify the distribution and abundance of these species, to find out their spreading characteristics, and to assess their impacts on the natural riparian habitats. According to our data, 11 plant species are threatening natural ecosystems in Romania, causing serious biodiversity losses. These species are: Acer negundo L., Ailanthus altissima (MILL.) SWINGLE, Ambrosia artemisiifolia L., Amorpha fruticosa L., Echinocystis lobata (MICHX.) TORR. & A. GRAY, Helianthus tuberosus L., Impatiens glandulifera ROYLE, Reynoutria japonica HOUTT., Reynoutria x bohemica CHRTEK & CHRTKOVÁ, Solidago canadensis L., Solidago gigantea AITON., and another 10 species are considered to be potentially dangerous for natural habitats. These species occur most frequently in ruderal habitats and riparian zones, but also roads and railways are highly affected. Our assessment is by no means complete, but it truly reflects the importance of this phenomenon. Implementing actions to control the future spread of these species is required with the cooperation of governmental and non-governmental organizations, scientific institutions, and the public as well.

Cuvinte cheie: plant invasion, non-indigenous species, riparian habitats