제주 동부지역에 위치한 2차 초지대의 생태환경에 따른 나비 분포특성

Abstract

This study was conducted to monitor and analyze the characteristics of butterfly distribution and community in various geographic and ecological environments in Jeju Island. The monitoring areas are mainly focused on farmland and wetlands, slope of Oreum, and Gotjawal region among the secondary grassland in the Eastern Jeju Island. Through the study, a total 3,575 butterflies of 37 species belong to 5 families were observed. Out of five Families, Nymphalidae were dominant group with 13 species and 1,560 individuals. The remainings were followed by Papilionidae with 5 families and 394 individuals, Pieridae with 6 families and 440 individuals, Lycaenidae with 7 families and 828 individuals, and Hesperiidae with 6 families and 353 individuals. Reviewing the monthly species abundance, August was highest with the number of 32 species, followed by September (28 species), April and July (26 species), and May (19 species). In the individual abundance, the number of individuals were peaked to 920 in July, followed by 785 in August, 774 in September, 655 in June, and 441 in May. When reviewing population by areas, Susan Gotjawal had the largest number of butterfly species with 34, while Yeongjusan and Hanmot were the next with 31 and 25 species, respectively. In the total number of butterflies, there were 1,556 in Yeongjusan, 1,037 in Hanmot, and 982 in Gotjawal. According to the individual number of major species in each area, species appeared in the order of Pseudozizeeria maha (361), Ypthima multistriata (197) and Minois dryas (183) in Yeongjusan. And it was occurred by Ypthima multistriata (171), Argyronome laodice (108) and Melanargia halimede (102) in Hanmot, and Ypthima multistriata (182), Pseudozizeeria maha (116) and Minois dryas (105) in Susan Gotjawal. The number of species per site was highest in Yeongjusan site 2 (30), followed by Susan Gotjawal site 1 (28) and site 2 (28). These sites had vegetatively various structures in comparison with the other sites: a mixed forest composed of herbaceous plants, shrubs and trees in the site 2 of Yeongjusan, shrubs and trees in Susan Gotjawal site, and herbaceous plants and shrubs in Susan Gotjawal site 2. The number of individuals per site was highest in Yeongjusan site 2 (743), followed by Youngjusan site 1(591) and Susan Gotjawal site 2 (512). In the analysis of species diversity indies, the dominance index was highest in Yeongjusan (0.35), while Susan Gotjawal (0.30) was ranked in the second and Hanmot (0.27) in the third with slight difference. Diversity index was similar among areas, with Yeongjusan 2.72, Hanmot 2.80, and Susan Gotjawal 2.76. Uniformity index was in the order of Hanmot (0.87), Yeongjusan (0.79), and Susan Gotjawal (0.78), and species abundance index was in the order of Susan Gotjawal (4.79), Yeongjusan (4.08) and Hanmot (3.46). In the cluster analysis based on the similarity of species composition, site 1 and 2 in Yeongjusan and site 2 in Susan Gotjawal were included in Group A, while remaining sites were included in Group B, indicating that sites in Group A had better environmental conditions for butterfly habitats. All three areas included grassland in common, but ecological environment were various: Yeongjusan with shrubs and black pine forests, Hanmot with wetland plants and agricultural crops, and Susan Gotjawal with shrubs and deciduous forests. There were 28 species of butterflies: Papilio xuthus, Eurema mandarina, Parnara guttatus etc. that feed on nectar plants. Pseudozizeeria maha obtained nectars from 13 kinds of plants such as Ranunculus japonicus and Potentilla fragarioides, and thus this species used the most nectar plants. A total 37 plant species were used as nectar source by butterflies, and 21 species of butterflies including Papilio xuthus and Eurema mandarina used the plant of Cirsium japonicum. Yeongjusan and Susan Gotjawal that include grazing area was recorded as high population abundance and species diversity among the monitoring areas, indicating the positive correlation between grazing and biodiversity of butterfly species. The grassland area in Jeju Island is decreasing rapidly due to the expansion of agricultural land, forestation by tree planting, and various industrial development. Considering the environmental risk above, studies on the ecological environment in the secondary grassland of eastern Jeju Island and related characteristics of butterfly distribution will be the fundamental basis of further study in butterfly habitats and preservation of ecosystem in Jeju Island.