Negative Impact of Invasive Plants on Riverbank Vegetation

The research presented in this paper deals with the issue of invasive plant species. Invasive plants are characterized with the high regeneration potential and with a negative effect on populations of our native species and habitats. The occurrence of these plant taxon at a given site is not natural, and their appearance outside of their natural habitat is most often due to anthropogenic activity. Our research is focused on plant species Fallopia japonica and Impatiens glandulifera . The aim of the study is the determination of suppressing possibilities of their negative impact on riverbank vegetation. From the results of the first stage of the research, it is known that plant material is transported downstream, the ability of reproduction of the plant material maintain for at least for 4 weeks, and after being caught on the riverbank, it can establish a new population. The overgrowth of these invasive species presents a risk to the original riverbank vegetation, and the ecological stability is being disturbed. The eradication and prevention system is a necessary solution to this problem. The research is conducted on the Blatina River in Pezinok, Slovakia. The first method of eradication was the mechanical removal of Fallopia japonica . The two selected localities were cut. In the next growing season, an increase in the population of Fallopia japonica was recorded, and one new location was created. The second method of eradication was the chemical method. For chemical eradication, spraying based on the Invasive Plant Removal Guidelines for the Slovak Republic was used. An important finding was that the effectiveness of the chemical eradication is dependent on the area of the sprayed leaves and independent on the concentration of the solution. The next step was the comparison of vegetation cover after mechanical and chemical eradication. A soil probe was performed on two selected areas; area after the mechanical eradication and the area after chemical eradication. A root sample was taken from both areas. Subsequently, the viability of the root system and its stabilizing function with respect to bank erosion were evaluated. The effectiveness of chemical eradication was much stronger. The most optimal way is to remove the plant at their early stage of the growing cycle when the leaf area is smaller. The result is then ecologically and economically more advantageous. After chemical eradication, it is necessary to remove dead plant residues in the autumn to create optimal light and wet conditions for the growth of potential natural vegetation. Invasive plants in riverbank vegetation have a negative impact on stability and potential natural vegetation. The best way to control their incidence is eradication.