Management and landscape of shelterbelts contribute to butterfly and flowering plant diversity in northern Japan

A considerably large number of shelterbelts were established in Japan to increase crop yields in agricultural landscapes. Shelterbelt landscapes have multiple functions; they not only help to control wind damage but also to conserve biodiversity, including forest and grassland species. However, previous studies on biodiversity conservation in shelterbelts, and the target taxa were limited since this aspect of shelterbelts has not received much attention in Japan. This study examines the effects of shelterbelts and their regeneration on the diversity of butterflies and flowering plants in the Tokachi region of Hokkaido, Japan. Using a transect method, we compared environmental factors, butterfly, and flowering plant diversity in four habitats: inside forest, forest edge, regeneration sites, and semi-natural grasslands which include shelterbelts and surrounding landscapes. There were significant differences in photosynthetically active radiation (PAR) among habitats, with higher PAR corresponding to higher numbers of butterfly species and individuals, and flowering plant species and flowers. Nonmetric multidimensional scaling results also showed that the species composition of flowering plants and butterflies differed among habitats. In addition, indicator value analysis showed that semi-natural grasslands and regeneration sites were characterized by endangered butterflies and their host plants. Our results indicated that shelterbelt regeneration and the surrounding environment (e.g., semi-natural grasslands) contributed to the diversity of butterflies and flowering plants, including endangered species. Future studies evaluating the diversity of various taxa would provide a more comprehensive understanding of the effects of shelterbelts on biodiversity conservation.