The Spine of a Peninsula
The Baekdudaegan is a continuous mountain range forming the primary watershed of the Korean Peninsula. This uninterrupted ridgeline stretches approximately 1,500 kilometers from Baekdusan mountain on the Chinese border south to Jirisan mountain in South Korea. Often called the "spine" of Korea, it is a critical ecological corridor and a reservoir of biodiversity. The South Korean portion alone is about 701 kilometers long and contains a large portion of the peninsula's wildlife.
The range acts as a refugium for species that survived the Last Glacial Maximum. This has resulted in high levels of genetic diversity. The South Korean section of the range may contain up to 1,500 plant species, which is about one-third of the total flora of the Korean Peninsula. It is a hotspot for threatened species, providing a habitat for at least 30 endangered animal species. Mammals found along the corridor include the long-tailed goral and leopard cats. At the Baekdudaegan National Arboretum, a 3.8-hectare "Tiger Forest" has been created to house Siberian tigers, reintroducing the symbolic predator to the mountain ecosystem.
A Tale of Two Slopes
The Baekdudaegan's north-south orientation creates a sharp climatic divide. The eastern slope faces the East Sea (Sea of Japan) and experiences a wetter, maritime climate with heavy snowfall. The western slope has a drier, more continental climate. This difference, occurring over just a few hundred meters of ridgeline, creates distinct habitats that limit gene flow for many species. As a result, populations of the same species on opposite slopes can show significant genetic differences.
This phenomenon is observable in both plants and animals. Studies on the Asian common toad (Bufo gargarizans) found a higher number of unique mitochondrial haplotypes in populations within the Baekdudaegan compared to lowland areas. Populations of the striped field mouse (Apodemus agrarius) along the ridge show significantly higher genetic diversity than those in lower habitats. For plants, the ridge is a barrier, leading to isolated evolution. Endemic species like the Korean fir (Abies koreana) are now largely restricted to subalpine zones above 1,000 meters. Climate change is causing these subalpine conifer habitats to shrink, placing species that are unable to migrate further up in elevation at risk.