Butterflies are commonly used for environmental monitoring to assess biodiversity changes in the world. Occurrence of butterflies were monitored by a line transect method in Gwangneung forest for 10 years from 2005 to 2014. Totally, 8,484 individuals of 96 species of butterflies were identified. Among them, two species Libythea celtis (2807 individuals) and Pieris melete (1517 individuals) were the most abundant species, followed by Argynnis paphia (381 individuals) and Neptis philyroides (277 individuals). Meanwhile, Pieris melete and Libythea celtis showed high occurrence frequency with 84.6% (99 times among the 117 monitoring times) and 76.9% (90 times) respectively, followed by Argynnis paphia (42.7%) and Pieris canidia (40.2%). Species richness and abundance were varied at different years, and they were slightly decreasing in recent years. Most species showed annual variation in their abundance. Species abundance distribution model showed a log-normal distribution.

• Tae-Sung Kwon(Forest Insect Pests and Diseases Division, Korea Forest Research Institute)
• Sung-Soo Kim(Research Institute for East Asian Environment and Biology)
• Cheol Min Lee(Forest and Climate Change Center, Korea Forest Research Institute)
• Young-Seuk Park(Department of Biology, Kyung Hee University)