Acta Scientiarum Polonorum
Silvarum Colendarum Ratio et Industria Lignaria

With increasing globalization, more and more plant species are being moved from their areas of natural occurrence to new ecosystems and parts of the world. A few species belong to the so-called invasive alien species with more or less negative impacts on their surrounding environnement. In the urban forests of Berlin, we can already find five plants on the "List of Invasive Alien Species Recognized as Threatening the European Union" (Ailanthus altissima (Mill.) Swingle, Asclepias syriaca L. Elodea nuttallii H. St. John, Heracleum mantegazzianum Sommier & Levier, Impatiens glandulifera Royle), and a dozen plant species considered invasive and potentially invasive by the German Federal Office for Nature Conservation (Bundesamt für Naturschutz).

However, not all of them are subject to eradication. The Berlin Forestry Administration and the Berlin Senate have focused on two groups of plants: species that have a significant negative impact on forest management, and species that threaten human and animal health and/or life.

The aim of this paper is to present the history of invasive species in the urban forests of Berlin. Furthermore, it discusses which invasive species pose the biggest problems from a natural and economic point of view, and describes the measures to reduce and control them that have been taken so far in Germany.

The paper discusses the importance of important species such as Prunus serotina Ehrh., Heracleum mantegazzianum and Ambrosia psilostachya L., as well as measures which have been taken so far to limit their populations.