Distribution and small-scale spread of the invasive weed Solanum carolinense in Austria.
Solanum carolinense is a perennial herb native to the United States which was accidentally introduced to Austria over 20 years ago. In this study, the current distribution of S. carolinense in Austria and its local spread dynamics in a selected agricultural area have been evaluated based on a literature search and a survey carried out in 2019. The species is an example of an invasive weed that is currently still rare in Austria as its distribution is restricted to southern Austria with only nine occupied grid cells. This corresponds to 0.3% of all grid cells (n = 2625) in Austria. However, the clustered appearance of the occupied grid cells and the small-scale spread observed within grid cells indicate an incipient spread. Thus, it can be assumed that the species will likely expand its range in Austria and beyond. It is therefore of importance to further survey S. carolinense and to observe its appearance in new areas in particular by raising awareness among farmers and agricultural advisors.