Climate Change Impact on Forest Cover using Warmth Index and Minimum Temperature in Korea

The objective of study was to predict the changes in regional forest distribution using the Warmth Index (WI) and minimum temperature index (MTI) in Korea. Previously, there were several trials to explain the forest cover changes in Korea using global-scale models, such as MC1 (MAPSS-CENTURY) and CEVSA (Carbon Exchange between Vegetation, Soil, and Atmosphere). However, these global vegetation models are not pertinent to simulate the climate change impact on relatively small Korean ecosystem. Therefore, the zonal distribution of WI and MTI was applied to interpret the spatial patterns of forest vegetation. Firstly, the climate data of past years (1971-2000) was prepared by Korea Meteorological Administration (KMA), and ECHO-G model provided future climate data under A1B scenario. Then, the optimal habitat rages of tree species were plotted by spatial distribution patterns of WI and MTI. In terms of cold tolerance for tree species, minimum monthly mean temperature of January (the coldest month) was converted to MTI, which related to intercellular freezing. MTI distribution of Korea in past years was ranged from -84.85 to 14. Overall MTI will be inclined in future period (2021-2050) and period (2071-2100), ranged from -80.91 to 19.45 and from 34.36 to -58.73, respectively. Also, WI was calculated by summing up of monthly mean temperature above 5 degrees Celsius. WI distribution of Korea in past years (1971-2000) was ranged from 72 to 132.9 degrees Celsius month. Overall WI will be increased in future period (2021-2050) and period (2071-2100), ranged from 81 to 147.9 degrees Celsius month and from 98 to 174.1 degrees Celsius month, respectively. As results of simulations, there were certain changes in vegetation distribution by climate change. The optimal habitat range of evergreen needleleaf species will be decreased and the range of deciduous and evergreen broadleaf species will be increased in the future; 1) especially, the optimal range of Pinus densiflora will shrink in the future, and 2) in southern part of Korea, the integration of WI and MTI tends to be laid over the optimal range for evergreen broadleaf species, such as Camellia japonica and Cyclobalanopsis glauca. The zonal distribution of integrated WI and MTI can explain more specifically than previous studies using only WI or MTI and global scale models.