Yeonsook Choung, Kyu Song Lee, Hyun Kyung Oh, Soyeon Cho, Youngjin Kim, Kyungeun Lee, Jaeyeon Lee and Sangyeop Jung. J Ecol Environ 2024;48:. https://doi.org/10.5141/jee.24.089

Aims: This study examines how burn severity and postfire initial regeneration shape long‐term forest recovery and successional trajectories in cool‐temperate Pinus densiflora forests of Korea. Location: Samcheok‐si, Gangwon Province, Republic of Korea, affected by the large‐scale East Coast Fire of 2000. Methods: Permanent plots were established in five stand types representing unburned (UB), light‐burn (LB), and severe‐burn (SB) conditions and, within SB stands, high (H), intermediate (I), and low (L) initial regeneration levels. Vegetation structure and species composition were monitored repeatedly over 20 years and analyzed using generalized additive mixed models and ordination techniques. Results: Postfire vegetation developed along distinct successional trajectories that were established shortly after fire and persisted throughout the 20‐year monitoring period. Temporal changes in vegetation structure and species richness differed consistently according to burn severity and postfire initial regeneration pattern. Tree regeneration played a central role in vertical stratification and canopy development. SB stands with high initial regeneration rapidly developed early‐stage forest structure and showed increasing dominance of Quercus and associated deciduous species. In contrast, stands with low regeneration exhibited delayed canopy development and prolonged dominance of shrub and herbaceous layers. LB stands followed a distinct recovery pathway, retaining P. densiflora dominance through the persistence of surviving canopy trees. Variation in regeneration level among SB stands resulted in divergent trajectories, ranging from Quercus ‐dominated stands to mixed Quercus – P. densiflora forests, indicating a successional shift away from prefire pine dominance. Species richness exhibited hump‐shaped temporal dynamics following fire. Conclusions: Postfire initial regeneration provides a strong and persistent signal of long‐term forest structure and successional trajectories. In particular, within SB stands, differences in early regeneration level further constrained recovery pathways for at least two decades. These findings highlight early postfire regeneration as a practical indicator for anticipating long‐term forest development and guiding postfire management strategies.

Long-term ecological research (LTER) provides an essential foundation for understanding ecosystem responses to climate change and environmental disturbances. Traditional dendrometry, based on one or two manual diameter breast height measurements per year, cannot capture short-term or seasonal growth fluctuations, highlighting the need for automated high-frequency monitoring. In Korea, however, high-resolution stem growth data for dominant temperate tree species remain scarce at the national scale. To address this gap, systematic high-resolution stem growth monitoring has been carried out at Mt. Jeombong since 2024, a core site of the “National Long-Term Ecological Research in Korea” program. This dataset presents high-resolution stem radial growth measurements for three representative temperate tree species (Quercus mongolica, Acer pseudosieboldianum, and Carpinus laxiflora) in the deciduous oak forest near the ecological observation tower in Mt. Jeombong. Automatic point dendrometers generated stem radial displacement and temperature measurements at 10-minute intervals for the entire year of 2024. From the raw measurements, hourly values were extracted and subsequently averaged to generate daily mean time series for visualization and interpretation. Analysis of the 2024 dataset showed that the three species exhibited broadly similar seasonal patterns of growth initiation, stabilization, and cessation, although some interspecific and individual-level differences were observed. Integrating these measurements with climate and other environmental variables is expected to yield deeper insights into the physiological drivers of these growth dynamics. Furthermore, the continuous radial growth data serve as valuable input for estimating stem carbon accumulation and improving assessments of forest net primary productivity. Long-term accumulation of comparable datasets will contribute to detecting climate-driven shifts in growth timing and carbon dynamics in Korean temperate forests.

Understanding the demographic mechanisms underlying the decline of endangered tree species is essential for developing effective conservation strategies. This study aimed to quantify the population trajectory and its demographic drivers in the Korean fir (Abies koreana), a subalpine conifer endemic to South Korea and listed as endangered by the IUCN, using a Bayesian Integral Projection Model (IPM). Based on eight years of field monitoring of survival, growth, and recruitment, the Bayesian IPM estimated the population growth rate (λ_s) and quantified its uncertainty under interannual environmental variation. The results indicated that interannual variation in drought, represented by the Standardized Precipitation–Evapotranspiration Index (SPEI), was a key driver of demographic changes. The mean population growth rate (λ = 0.983) suggests a slow decline, primarily driven by high mortality among intermediate-sized individuals, which are vital for maintaining population stability. In contrast, the growth of small to medium trees showed a weak but positive elasticity, implying that management actions targeting these size classes could benefit population persistence. Accordingly, effective conservation of A. koreana should focus on mitigating drought stress through reducing competition and improving soil moisture and structure.