Growth Dynamics of Korean fir (Abies koreana) Populations in the Western Area of Jirisan National Park (2011~2018)

This study analyzed species composition, population dynamics, diameter growth, vitality, and competition pressure to un- derstand the growth dynamics of the Abies koreana population in the western part of Jirisan National Park. Extreme drought in the spring of 2011 and powerful typhoons in Bolaven and Sanba in 2012 had direct and indirect effects on mortality, growth decline, vital- ity, and changes in species composition of A. koreana communities after 2014. Additionally, competition pressure from the climbing plant Tripterygium regelii was found to contribute to the decline in A. koreana. Notably, even within the western region, the degree of mortality varied by microhabitat, and younger A. koreana populations tended to remain stable. In areas with high mortality rates, a transition to broad-leaved tree species such as Quercus mongolica and Betula ermanii was observed. Unlike A. koreana, these broad-leaved tree species, unlike A. koreana, did not exhibit a tendency to decline under the same environmental conditions. Through this study, we were able to infer the environmental events that directly and indirectly influenced the mortality of A. koreana and recognized the importance of its life cycle in determining resistance to such environmental events.