The loss, gain, and diversity of butterfly species due to the development of PT PKWE oil palm plantation, West Kalimantan Province

Abstract

An increase in oil palm plantation area of ± 9.3 million hectares within 20 years (1997 – 2006) raises concerns of the international communities on the loss of diversity, including butterflies. Butterflies have multiple ecological functions, including as pollinator and ecosystem balancer, hence research about the impact of oil palm plantation development on the loss, gain, and diversity is important to conduct. The research was conducted in March 2018 in PKWE Plantation, West Kalimantan Province, by using Pollard transect method and trap in seven land covers. The land covers consist of two original land covers before made into oil palm plantation, in the form of shrubs and secondary forest, and five land covers after made into oil palm plantation, in the form of old, medium, young oil palm plantation, High Conservation Value (NKT) area, and yard. The total butterfly species found amounted to 49 species, 315 individuals, four families: Papilionidae (8 species), Pieridae (8 species), Nymphalidae (31 species), and Lycanidae (2 species). The highest number of species and diversity were discovered in the High Conservation Value (HCV) area (S=26; Dmg=6.24), while the lowest ones were located in a yard area (S=11; Dmg=2.09). Based on conservation status, there were a butterfly species which is protected namely Troides helena. Regarding the loss and gain of butterfly species, oil palm plantation development had caused a much lower loss than gain. With the loss of five species and gain of 27 species compared to the original land cover in the form of secondary forest, and the loss of three species and gain of 26 species compared to the original land cover in the form of shrubs.