Analysis of Species Composition and Distribution Changes in South Korean Forests Using the Individual Tree Data

The distribution and composition of tree species in forests play a pivotal role in forest ecology, management, and carbon cycling. Consequently, their assessment and prediction are of paramount importance for effective forest management planning and the formulation of climate change adaptation strategies, both at local and national scales. The primary objective of this study was to interpret and forecast patterns of tree species distribution changes observed within Korean forests. To achieve this goal, we utilized data from the 5th to 7th National Forest Inventory to construct basal area data for all tree species within each permanent plot. Subsequently, we conducted a comprehensive analysis of the changing trends exhibited by each tree species. Additionally, we calculated climatic environmental indices highly relevant to tree species distribution using meteorological data provided by the Korea Meteorological Administration. Furthermore, a tree species distribution prediction model was developed by applying the Generalized Additive Model (GAM). Our analysis revealed that prominent tree species with a significant distribution presence in Korean forests included Pinus densiflora (36.2%), Quercus mongolica (14.6%), Quercus variabilis BL (11.0%), Quercus serrata Murray (4.3%), Pinus rigida (3.6%), Larix kaempferi (3.2%), Quercus acutissima (2.8%), and Pinus koraiensis (2.4%), based on basal area. Notably, Pinus densiflora, Quercus mongolica, and Pinus rigida showed a consistent decline in forest area. Furthermore, the results from the GAM analysis highlighted a substantial correlation between changes in basal area among major tree species and climate indices, including the Warmth Index (WI), Precipitation Effectiveness Index (PEI), and Minimum Temperature of the Coldest Month Index (MTCI). Forest age also emerged as a closely associated factor. The findings of this study hold significant implications, as they enable us to anticipate future alterations in tree species distributions attributable to natural selection and climate change. In addition, this is the first research using the individual tree-level for develping the tree species distribution model in South Korea. 

∗This work was supported by Korea Environment Industry & Technology Institute through Climate Change R&D Project for New Climate Regime, funded by Korea Ministry of Environment (RS-2022-KE002294).