Discrepancies between non-native and invasive species classifications

Biological invasions pose a growing threat to ecosystems, biodiversity, and socio-economic interests. In the European Union, the introduction of non-native species through trade, tourism, and other pathways has led to unintended consequences. Among these non-native species, a subset exhibits negative impacts and is commonly referred to as ‘invasive’. However, the number of non-native species and the proportion considered invasive vary across different member states of the European Union. Classifications and definitions of invasive species also differ among countries potentially leading to an underrepresentation. Here, we use Germany as a case study to highlight gaps in invasive species classifications. The number of non-native species reported as invasive in Germany remains low (~ 14%) compared to other European Union member states (~ 22%), despite Germany’s strong economy, significant research investments, and well-established trade networks. This disparities may be attributed to complex and multifaceted factors, encompassing differences in classifications, variations in research effort and focus, and diverse national priorities. We further propose that the impacts of non-native species on resources and biodiversity may be more likely to be overlooked, principally in large economies reliant on international trade, such as Germany. This oversight could negatively affect conservation efforts and funding for research aimed at improving understanding invasive species threats. We suggest that this underreporting may stem from a focus on maintaining economic growth, which might have taken precedence over addressing the potential ecological and economic impacts of invasive species.