This chapter addresses the critical issue of diminishing biodiversity resulting from climate change and habitat loss in Korea and is largely based on a study by Choi et al. (Journal of Environmental Management 288, 2021). International endeavors to safeguard biodiversity face the challenge of accurately quantifying and predicting its shifts. Focusing on the Republic of Korea (ROK), a region renowned for its rapid reforestation, the study seeks to evaluate the enduring biodiversity of plant species from the 1960s to the 2050s, with a specific emphasis on the consequences of reforestation efforts. Employing a fusion of global-scale methodologies and localized data, the study simulates transformations in climate change, land use, and habitat condition, culminating in an analysis of their collective influence on biodiversity. The specific methodology details can be found in Choi et al. (Journal of Environmental Management 288, 2021), with key findings presented in this chapter. It is simulated that biodiversity is deteriorating due to habitat fragmentation and reduced connectivity caused by urbanization, alongside the impacts of climate change. However, a key conclusion drawn is that consistent efforts in forest conservation can mitigate these adverse effects. This research augments our understanding of biodiversity preservation amid the intricate interplay of complex factors, exemplified by the case of the ROK.