Raum: ÖBG, 4.1.00.13
Dr. Marianne Lauerer, ÖBG
Prof. Dr. Heike Feldhaar, TÖK I - Populationsökologie der Tiere
Within the last decades global change has rapidly accelerated. Biological invasions, human caused immigration of species, are an important component of these changes and a major threat to ecosystem functions and biodiversity. For the decision how to deal with this aliens one has to know whether they are drivers of the ecosystem changes or whether they only benefit from them. But there are interactions between each species and its invaded ecosystems so it is necessary to judge on them depending on the context.
In my PhD project context dependencies between an invasive model plant species, Impatiens glandulifera (Himalayan Balsam), and different invaded ecosystems should be investigated distinguishing cause and effect. Several studies reported on negative influences of the Balsam on different components of native ecosystems but regarding plant communities there are contradictory results so further research is needed.
The ability of I. glandulifera to compete against co-occuring species but also the ability to tolerate competition should be examined depending on habitat and the plants' stages of life. This should be investigated in a field study by removing and adding the Balsam at invaded resp. uninvaded sites. Further experiments with selected co-occuring native plants should be done on the influence of I. glandulifera on the natives' germination and establishment but also on the influence of established natives on the development of I. glandulifera.
It is expected that I. glandulifera is able to suppress native plants and alter their communities but also that it establishes hardly in close native vegetation sites. In the end it also should be possible to estimate whether I. glandulifera is the driver of the changes and whether it could be outcompeted by some native plant species. Knowledge on these issues is important for developing suitable management strategies on I. glandulifera.