Inventory of woody plants at landslide-prone areas in the Yufeng watershed of Taiwan

Abstract:

Native woody plants are fundamental considerations for natural-based landscape conservation in landslide-prone areas. However, comprehensive inventory of woody plants in these areas are quite rare in Taiwan. To build native woody plant database in landslide-prone areas, we investigated the woody species composition and phenology using a high magnification camera at 6 landslide areas in the Yufeng watershed. With pictures taken once a month for a year, we recorded the woody species at each site, and explored linkages with historical landslide disturbances. Investigation results showed a high diversity of woody species richness ranging from 19 to 46 at these sites. Compiling the composition of woody species we discovered different vegetation succession stages, including the pioneering colonization of Japanese mallotus (Mallotus japonicus), India-charcoal trema (Trema orientalis), common paper mulberry (Broussonetia papyrifera), Formosan alder (Alnus formosana), and Taiwan red pine (Pinus taiwanensis), with a mix of a variety of woody plants representing the afterward succession stages, including many indigenous endemic species, like Taiwan eugenia (Syzygium formosanum), Taiwan flame gold (Koelreuteria henryi), indigenous cinnamon tree (Cinnamomum insularimontanum), and Taiwan hibiscus (Hibiscus taiwanensis Hu). Moreover, we found a total of 13 woody species commonly seen at these landslide areas. Under successive landslide events, we revealed that the woody species composition was structured by the composite stimuli from complex interaction and competition of natural disturbances. This suggests that effective landscape conservation planning requires understanding of the local native woody plant composition, as well as consideration of the current landscape conditions, the historical environmental settings, and natural disturbances.