Soil mesofauna and diversity of vegetation: Collembola in pristine taiga forests (Pechora-Ilych Biosphere Reserve, Russia)

摘要

Unique 600-year-old tall herb taiga forests are located in the European North-East of Russia at the foothills of the Middle Urals and are characterized by extremely diverse and vertically differentiated vegetation. This study addresses how vegetation parameters such as net primary productivity and diversity influence the community structure of Collembola in fir forests of different ages. Sample plots were arranged along diversity and biomass gradients of vegetation: Vaccinium-moss, short herb-moss, and nitrophilous tall herb fir-spruce forests. Plants and collembolans were compared with respect to their species richness, abundance, species structure and traits. The number of species of vascular plants, mosses and liverworts along the studied gradient increased by about double, whereas the species richness of collembolans did not differ significantly. The biomass of vascular plants increased, whereas that of mosses declined, and the abundance of collembolans remained approximately consistent. Despite sharp differences in ground vegetation, in all phytocenoses the dominant Collembola species were widespread. However, the collembolan community of old-growth tall herb forests showed a trend of more complex structure reflected by greater evenness of abundances compared to younger ecosystems with less diverse ground vegetation. In conclusion, the springtail communities in forests that have developed spontaneously for over 600years appeared to be no more complex than those in 200-year-old stands. Multi-species ground vegetation did not increase collembolan diversity and abundance indices. Thus, soil mesofauna (in this case, springtails) appeared to be relatively independent of long-term spontaneous development in vegetation in the studied area.