Identifying characteristics of post-landslide habitats and potential native herbaceous species for revegetation after landslides across Taiwan

In Taiwan, using exotic plants for landslide revegetation has sparked concerns over biological invasion. This study focuses on identifying native herbaceous species suitable for landslide revegetation across Taiwan. We analyzed environmental factors of post-landslide habitats (PLHs) island-wide and developed a classification system with 20 habitat types, which were organized by elevation (0–3,100 m) and aspect. A preliminary list of 319 species with potential for landslide revegetation was established with three sources: revegetation guidebooks, field studies, and expert questionnaires. These species were refined to 42 native species by excluding exotics and less-mentioned or -abundant species. Many of these native species were characterized by traits of long-distance dispersal, heat, and drought tolerance, which can promote plant establishment and survival in PLHs. To determine species suitable for the 20 identified PLHs, we used GIS to segment Taiwan into these habitat categories and assessed the presence frequency of the 42 species across them. The analysis indicated that the number of suitable species decreases with elevation, with a shift towards temperate species at higher altitudes, while the aspect had minimal impact on species suitability. This suggests that elevation is a key determinant in selecting appropriate species for revegetation. Our study developed a systematic method for compiling a native species list for Taiwan's varied PLHs, highlighting the importance of native plant diversity in sustainable landslide recovery and ecosystem restoration, while reducing the risks of biological invasions by minimizing the use of exotic species.