Su-Young Woo1, Jong Whan Lim2, Sun Mi Je3, Don Koo Lee4, Mi Jeoung Kwon5, and SooZin Ryang3. (1) University of Seoul/Department of Environmental Horticulture, Dongdaemungu Jeonnongdong, 90, Seoul, 130-743, South Korea, (2) Korea Forest Research Institute, Dongdaemungu Chongrangridong, 207, Seoul, 130-712, South Korea, (3) University of Seoul, Department of Environmental Horticulture, Dongdaemungu Jeonnongdong, 90, Seoul, 130-743, South Korea, (4) Seoul National University, Department Forest Science, Kwanak gu Silim Dong, 56, Seoul, South Korea, (5) Seoul National University, National Instrumentation Center for Environmental Management, Kwanak gu Silim Dong, 56, Seoul, South Korea
We established three permanent plots in the Korean fir forest near the top of Mt. Halla, between damaged and healthy populations. Three sites in this study showed similar physical environments, helping to minimize variations. Meteorological data in the permanent plots, photosynthetic rate, and water use efficiency were evaluated to explain the forest dieback phenomenon on Korean fir population. Obviously, mean air temperatures of study areas during last 40 years have been increased, especially in winter and spring seasons. Irradiance response curve of healthy Korean fir population were higher than unhealthy population at all three sites. In contrast, damaged trees showed higher WUE than those of healthy tress. The both irradiance response curve and WUE showed higher values in lower air temperature. As evidences of Korean fir dieback, climatic change and physiological characteristics have been emerging to explain the cause of decline in this area. It may seem to result in winter desiccation and frost in this area. Warmer climate should have affected on the water balance regime of Korean fir population in case available soil moisture was not enough.