The distribution shift of forest species due to the fact of climate change may negatively affect ecosystem services including the production of medicinal resources. Climate change impact assessments of habitat range changes are essential to sustainably manage forest resources. A change in the habitat suitability due to the fact of climate change was predicted for Angelica gigas, which has high economic value among forest medicinal resources in South Korea. The habitat suitability was predicted by an ensemble species distribution model that combined the results of nine single algorithm models using the committee averaging method. A total 168 occurrence data and 10 environmental variables were used for the single algorithm models. The area under the receiver operation characteristic curve (AUC) and true skill statistic (TSS) were applied to evaluate the models’ performance, and the contribution of the environmental variables was calculated as an important value for each single algorithm model. Climate change scenarios were projected to predict future habitat suitability. The future suitable habitat for A. gigas was gradually reduced to the high mountain regions of the eastern part of South Korea regardless of the climate change scenarios. The main environmental variable was the annual mean temperature, and the rise in temperature due to the fact of climate change was found to have a negative effect on the habitat suitability for A. gigas. The decline in the habitat suitability for A. gigas, a major forest medicinal resource, is expected to result in the reduction in its production. Therefore, it is required to establish adaptation measures to mitigate the negative impact of this decrease, such as protecting the natural habitats of A. gigas.

Oak decline syndrome has been observed in South Korea and Japan and variously referred to as Korean oak wilt (KOW) and Japanese oak wilt (JOW). We reviewed aspects of the historical occurrence of KOW, disease cycle, and its potential causes. KOW has been seen principally in Mongolian oak (Quercus mongolica Fisch. ex Ledeb.). The first occurrence of KOW was in 2004 in Seongnam, South Korea. KOW is associated with the fungus Raffaelea quercus-mongolicae, which is vectored by the ambrosia beetle Platypus koryoensis. In addition, it has been suggested that yeasts have evolved a symbiotic relationship with the vector without antagonism for the pathogenic fungus. The number of trees in Korea killed by KOW increased to about 331,000 in 2011, but then decreased to about 157,000 in 2019. We hypothesized that trees infected by R. quercus-mongolicae accumulate phenolic compounds in the sapwood and the vector (P. koryoensis) beetles then avoid these trees. Therefore, the number of hosts available for the beetle after a KOW outbreak decrease due to accumulation of phenolic compounds in the wood, although most oak trees survive outbreaks. Therefore, P. koryoensis beetles move longer distances after outbreaks to find susceptible host trees. Novel occurrence of KOW in Korea may be due to either (1) an increase in tree age (size) in Korean oak stands, for which the beetle has a known preference or (2) climate change, which may be increasing the number of weakened or stressed trees, for which P. koryoensis also shows a preference.

Exotic species plantations are increasing for timber production and other economic benefits. However, evaluation of species adaptation to local climates requires long-term research and the information is still limited. This study was conducted to understand the growth response of three exotic tree species, Abies firma, Cryptomeria japonica, and Chamaecyparis obtusa, to regional moisture conditions during the dry spring and wet summer in plantations located in south-central Korea. We examined the growth response of A. firma, C. japonica, and C. obtusa to monthly precipitation and drought indices from 1950 to 1998 using tree-ring analysis. The radial growth of A. firma showed a significantly positive relationship with precipitation and drought indices in spring (p < 0.05). Water stress in spring was the main limitation to radial growth in A. firma. In contrast, C. japonica and C. obtusa, with indeterminate growth, had negative correlations with precipitation and drought indices in summer (p < 0.05). Abnormally high summer precipitation may interrupt photosynthesis by reducing sunshine duration and evaporation, negatively affecting the growth of C. japonica and C. obtusa. The different responses of these species to monthly precipitation and drought indices imply that regional precipitation patterns should be carefully considered in species selection for the establishment of exotic species plantations.