Vegetation Changes and Management Plans for the Godeok Riverside Restoration Area along the Hangang River in Seoul

Background and objective: This study aimed to identify trends in plant ecosystem changes and propose management measures to enhance biodiversity by monitoring the flora and existing vegetation in the Godeok Riverside Ecological Restoration Area along the Hangang River in Seoul, Korea, from 2003 to 2021. Methods: Flora identification took place in 2003, 2005, 2010, 2015, and 2021, aligning with Lee's studies (2003). The existing vegetation was also surveyed at the same intervals, plotting it on a 1:1,000 scale topographic map of Seoul according to the vegetation association of the dominant layers, whether woody or herbaceous. Results: Observations indicate a consistent decline in the number of species from 2003 to 2021. Naturalized species levels remained stable after a slight decrease in 2003, with ecosystem-disturbing plants consistently observed at 4-6 species. Since the stabilization of vegetation in 2005, there has been no significant change in species composition. Regarding changes in existing vegetation, the vegetation type was initially simple after the 2003 restoration. However, after stabilization in 2005, some planted native riparian species became established and formed communities, with the area of Salix pierotii communities notably increasing. Native wetland herbs have shown fluctuating trends since 2003, with an overall decrease. Naturalized herbs expanded in 2005 after restoration, but subsequently declined with continued management. Conclusion: The management plan for enhancing biodiversity proposes managing the riverside Salix pierotii community inside the restoration area based on the monitored growth of Salix pierotii and changes in understory vegetation. The waterside planting area, subject to disturbance and transitional vegetation changes, requires the introduction of native species, and the maintenance and removal of vegetation. For the primary disturbed area, the focus should be on conserving native plant vegetation and securing a buffer zone.