Monitoring the spread of invasive plant species in Germany – how many species can we possibly detect by remote sensing and what data do we need?

Combining remote sensing and field data allows for the detection of some invasive alien plant species with an adequate accuracy. Especially the use of satellite data for larger areas or UAS (unmanned aerial system) data for smaller sites may provide alternatives to classical field mapping approaches. A main advantage is that satellite or UAS data is potentially more cost-efficient then the use of for example hyperspectral data, which was frequently applied in research on the detectability of invasive species in the past. This study discusses the possibilities and limitations of remote sensing to contribute to the detection of invasive alien plant species in Germany. Taking into account previous studies on the topic, we estimate the potential for a successful detection of relevant invasive plant species in Germany. Main criteria to determine the potential for detection are the species characteristics (size, detectable traits, habitat) as well as their similarity to other native species. For 19 of the 42 species examined, the use of remote sensing data is most probably successful, mainly for larger species and species with characteristic features such as colorful flowers or leaves. For another 10 species the detection might eventually be feasible. For about 13 species, especially hydrophytes living below the water surface and other species lacking any characteristic features, the detection is currently not possible. We can conclude that remote sensing remote may offer efficient solutions for a small or large scale monitoring of certain invasive plant species or to control the management success and thus support decision-making. In general, more research is needed to develop cost-efficient and user-friendly solutions.