Determinants of Butterfly Community Structure and Composition at the Local Habitat Level: Importance of Neighbouring Vegetation and Management Status

Exploring the determinants of biological community structure is important not only for understanding the formation of the community, but also for promoting its biodiversity conservation. We monitored butterfly communities in a grassland and woodland area of Mount Fuji, Japan, and explored the environmental factors that influenced them. Multivariate regression tree (MRT) analysis generated a 3-leaved MRT (G1, G2, and G3) and showed the total explained variation of 64.4% in the species composition. The explanatory variables discriminating between the two branches in the first node and in the second node of the MRT were neighbouring plant community and management status, respectively. The neighbouring plant community was related to the distribution of butterfly dietary resources and contributed much in determining the species composition of the community. While the management status was largely related to the amount of their dietary resources, affecting the species richness and diversity. The PCA results revealed that the three key groups (G1, G2, and G3) were formed along the gradients of these two factors. Consequently, to maintain mowing management and the diversity of neighbouring vegetation is very important for the continuance of butterfly community diversity and composition and the conservation of Red Listed species in the area.