Effects of landscape structural changes on species composition in mountainous rural communities

Abstract

Farming and other traditional land uses are being abandoned in mountainous rural communities throughout Japan. This study investigated factors influencing this trend and the effects of resulting landscape structural changes on species composition and function in four taxa in 20 rural communities of the village of Otari, at the foot of the Hakuba Mountains in Nagano Prefecture, Japan. The four taxa (birds, butterflies, ground-dwelling beetles, and plants) were selected for their different dispersal and resource dependence characteristics. Generalised linear model (GLM) analyses showed that the number of houses (as an index of workforce) and solar radiation amount (as an index of crop productivity) significantly influenced declines in farmland and landscape diversity from the 1950s to the present. Landscape structural changes significantly affected the species composition of the four taxa according to nonmetric multidimensional scaling ordination, as well as the numbers of individual migratory birds, univoltine butterflies, and specialist ground beetles according to GLM analysis. We conclude that the natural and socioeconomic factors controlling the persistence of rural communities played a significant role in altering the landscape structure in the study region, which in turn affected the species and functional composition of biological communities.