Assemblage Characteristics and Habitat Specificity of Carabid Beetles in a Japanese Alpine-Subalpine Zone

In lowland areas of the world and high-altitude European mountains, the species compositions, body sizes, and wing forms of carabid beetles are known to change according to vegetation structures. However, little is known regarding the assemblage structure and habitat associations of carabid beetles in Japanese alpine-subalpine areas. We surveyed carabid beetles in four habitats (snow beds, alpine meadows, Pinus scrub, and fell-fields) in the alpine-subalpine zone on Mt. Hakusan, Japan. We surveyed carabid beetles six times between mid-July and late September. Nonmetric multidimensional scaling (NMDS) and analysis of similarities (ANOSIM) revealed three distinct carabid beetle assemblages in snow beds and alpine meadows, Pinus scrub, and fell-fields. The carabid beetle assemblages in the four habitats consisted predominantly of small and/or wingless species with differential spatiotemporal variability in abundance. Biota-environment (BIO-ENV) analyses showed that the percentage coverage by Pinus scrub, soil water content, and ground surface temperature were among the most significant variables affecting carabid beetle compositions. Given their small sizes and reduced wings, which are characteristic traits for limited mobility, and high-level habitat specificity, carabid beetles in the alpine-subalpine zone may serve as an important target group to monitor the impacts of global environmental change on mountain ecosystems.