Species Assemblage and Biogeography of Japanese Protura (Hexapoda) in Forest Soils

The distribution and species assembly of Japanese Protura collected from forest soils were examined using published databases and statistical analysis. We used records from 3110 sites where 71 taxa were found. The species richness of Protura ranged from one to 16 species, and TWINSPAN analysis of regional populations indicated that the northern and southern regions could be separated into distinct groups. Three major species assemblages were identified by cluster analysis from points containing more than six species. Three groups reflected historical migration from northern and western linkages to the Asian continent. The northern assemblage showed a negative correlation to winter minimum temperature and the other two assemblages exhibited relationships to precipitation and temperature. Vegetation was not responsible for proturan distribution. These results suggest that the history of Protura invasion explains the biogeography of these soil-based, small arthropods and also that climate change will induce a shift in the distribution of species irrespective of changes in vegetation type.