The forest at the Changdeokgung Rear Garden is under ecological threat from factors such as soil acidification due to the growing influence of nearby metropolitan Seoul. It is difficult to maintain biodiversity in forests without first setting a clear direction for ecosystem management. Conservation and management should be based on the history and natural ecological succession of the Rear Garden forest. This study classified the ecology of the Rear Garden at Changdeokgung, a world cultural heritage site, based on soil characteristics, actual vegetation, and plant community structure and identified ecological changes over time (1986–2018) through the analysis of past survey data. The soil pH in the forest of the Changdeokgung’s Rear Garden has decreased over time, and the organic matter content has also decreased. Changdeokgung’s Rear Garden was first created and managed as a Pinus densiflora forest, and subsequently as a Quercus aliena forest. It includes a series of Quercus spp., predominantly Q. serrate. The plant community in the forest is unstable due to the absence of deciduous broad-leaved trees in the understory layer in most of the regions of the garden. Therefore, vegetation management is required in areas with high densities of Acer pseudosieboldianum, Acer palmatum, and Sorbus alnifolia to ensure the stability of the ecosystem.
