Temperate forest ecosystems in Korea are currently undergoing a successional transition from Pinus densiflora Siebold & Zucc. (evergreen conifer) communities to Quercus mongolica Fisch. ex Ledeb. (deciduous broadleaf) communities. This study aimed to assess interspecific differences in ecological responses to climate change [Representative Concentration Pathway (RCP) 4.5] by evaluating changes in ecological niche characteristics and species distribution. Controlled-environment experiments, principal component analysis (PCA), and MaxEnt species distribution modeling were employed to quantify and predict ecological shifts in the two dominant species under climate change scenarios. Both species exhibited increases in niche breadth and interspecific overlap under climate change conditions. However, Q. mongolica showed a more pronounced increase in niche breadth compared to P. densiflora, indicating greater ecological flexibility and adaptive potential to warming conditions. According to the MaxEnt model projections, climate change is expected to result in an approximate 30% reduction in suitable habitat for P. densiflora in lowland areas. In contrast, Q. mongolica is projected to expand its suitable habitat by over 80%, notably in both low-elevation (below 800 m) and high-elevation (above 1400 m) zones, without being restricted to any specific altitudinal range. Our findings suggest that climate change may increase ecological similarity between P. densiflora and Q. mongolica, thereby raising the potential for interspecific competition. This convergence in niche traits could contribute to an accelerated successional transition, although actual competitive interactions in natural ecosystems require further empirical validation. Consequently, Korean forests are likely to transform into predominantly deciduous forest ecosystems under future climate conditions.

Ju-Seon Lee, Young-Han You*, Ji-Won Park, Yeo-Bin Park, Yoon-Seo Kim, Jung-Min Lee, Hae-In Yu, Bo-Yeon Jeon, Kyeong-Mi Cho and Eui-Joo Kim*. J Ecol Environ 2024;48:. https://doi.org/10.5141/jee.24.051

Managed plantation forests are important for timber production and carbon sequestration, but their biodiversity value compared with unmanaged secondary forests remains debated. We compared vascular plant diversity between a managed Japanese larch (Larix kaempferi) planted forest (MPF) and a nearby unmanaged secondary Mongolian oak (Quercus mongolica) forest (USF) in the Garisan Leading Forest Management Complex, Hongcheon-gun, Republic of Korea, where stand age and site conditions were broadly comparable. Using Modified-Whittaker plots across 1–1,000 m² at five sites per forest type, we analyzed pooled species richness of total vascular plants, spring-active herbs, native species, and alien species, and estimated species accumulation using species–area slopes. We also examined taxonomic structure with hierarchical diversity partitioning and dominance patterns using rank–abundance curves. Total species richness was significantly higher in the MPF across all plot sizes, and species accumulated more rapidly with area than in the USF (b = 14.14 vs. 4.48). Spring-active herbs and native species were also richer in the MPF, with steeper species–area slopes. Alien species occurred slightly more often in the MPF but remained scarce in both forest types. The MPF had significantly higher within-family genus diversity, whereas within-genus species diversity did not differ. These results suggest that early understory control, periodic thinning, microsite heterogeneity, and the spring light window under deciduous larch can promote understory plant diversity in mid-aged managed plantations.

Jung-min Lee, Eui-Joo Kim, Ji-won Park, Yeo-bin Park, Jae-hoon Park and Young-Han You. J Ecol Environ 2025;49:. https://doi.org/10.5141/jee.25.035

Tidal flats contain large sediment carbon reservoirs, but blue-carbon accounting has generally focused on soil organic carbon (SOC), whereas shell-derived particulate inorganic carbon (PIC) has rarely been quantified in unvegetated tidal flats. Here, we quantified SOC, PIC, and total carbon (TC) stocks in 0-50 cm sediment cores collected from three sediment facies (mud, mixed, and sand flats) in the Shinan tidal flats along the southwestern coast of Korea. Sediment facies strongly controlled carbon storage, with mean SOC stocks of 159.84, 72.06, and 28.31 Mg C ha−1 and mean PIC stocks of 26.46, 9.10, and 4.53 Mg C ha−1 in mud, mixed, and sand flats, respectively. PIC contributed 11-14% of TC across all facies. Factorial ANOVA showed significant sediment-facies effects on SOC, PIC, and TC, whereas depth (0-50 cm) was not significant. The sediment facies x depth interaction was significant for SOC and TC but not for PIC, suggesting that the vertical distribution of organic carbon varied among sediment types. These results demonstrate strong spatial heterogeneity in sediment carbon storage across tidal-flat facies and indicate that PIC can represent a durable, non-negligible component of sediment carbon inventories. In this study, PIC is interpreted as a sediment carbon stock rather than a net atmospheric CO2 sequestration flux.