Ingmar R. Staude

Amidst global challenges like climate change, plant dispersal corridors are essential. In human-dominated landscapes, urban and rural green spaces are key dispersal avenues. Non-native plants are known to benefit from these, yet the potential benefits for endangered plants remain unclear. To address this question, I compared dispersal traits of endangered native plants with those of non-endangered and non-native species in Germany. I also compared endangered species amenable to gardening with non-native garden escapees to make my analysis pertinent to understanding the potential role of gardens in aiding native plant dispersal. I analyzed several traits including seed weight, terminal velocity, dispersal distance, germination rate, dispersal mode, seed structures, and seedbank type. Overall, dispersal traits between native and non-native plants showed minor, but in some cases statistically clear differences. Endangered plants were more often wind-dispersed and had more frequently seed appendages that might encourage a wider range of dispersal vectors. In contrast, non-native plants leaned more towards non-assisted local dispersal with slightly heavier seeds and more persistent seed banks. The other traits were largely consistent across groups. Given the minor differences in dispersal traits, green corridors may provide no lesser dispersal avenue for endangered native species. Gardens that have historically aided the dispersal of many non-native plants, could support the dispersal of endangered native plants instead.