Changes in diversity and body size of Onychiurinae (Collembola: Onychiuridae) along an altitudinal gradient in Changbai Mountain, China

Abstract

Collembola are among the most abundant and diverse soil animals contributing significantly to major ecosystem processes. Global climate changes in temperature and precipitation are likely to affect their community structure and functioning and this is likely to differ along altitudinal gradients. In this study, changes in richness, abundance, and body size of onychiurin Collembola with altitude have been investigated in the Changbai Mountain range of northeast China. Sampling was carried out on a 30 km long transect along forested slopes of the Changbai Mountains. Standardized samples were taken from 800 to 1700 m at seven altitudinal levels. More than 5000 specimens of Onychiurinae representing 13 species were collected, making Onychiuridae (with the sole subfamily Onychiurinae in Changbai) the most abundant Collembolan family in the area. The number of species of Onychiurinae slightly increased along the altitudinal gradient. The average number of species per sample, but not the total abundance, changed significantly but not monotonically with altitude. Body size of Onychiurinae species decreased significantly with increasing altitude contradicting Bergmann’s rule. Furthermore, the abundance of the three body-size groups differentially responded to increasing altitude, with the abundance of the large body-size group decreasing and the abundance of the small body-size group increasing. Our results suggest that the distribution patterns of Collembola along the altitudinal gradient are complicated and may be linked to taxonomic groups and bioclimatic zones.