Divergent patterns and assembly processes of soil fungal abundant and rare communities along an elevational gradient in subalpine areas of Southwest China

Abstract

Abstract Aim Understanding the patterns and assembly processes of microbial communities along an elevational gradient remains largely debated. Methods We examined soil fungal abundant and rare communities and the underlying drives across a wide elevation from 2100-3950 m (a. s. l.) along the Yulong Mountain of Southwest China. Results We found the abundant and rare taxa were divergent in diversity, and only the α diversity of abundant taxa followed a humpback trend and peaked at 2900 m, despite the β diversity were significantly dependent on elevation gradients. Soil fungal abundant and rare taxa showed significant elevation-decay relationship, with more dispersal limitation to abundant taxa than that of rare taxa. Along the elevational gradients, the assembly of abundant fungal sub-communities were governed by combined effect of both environmental factors (soil nitrogen and potassium, soil temperature) and dispersal limitation, whereas the rare fungal sub-communities were merely dominated by stochastic processes (ecological drifts). Network modules analysis revealed higher functional redundancy in rare fungal sub-communities and this influence reinforced neutrality, and hence impelled rare fungal more susceptible to drift. Conclusion Our results suggested the divergent pattern and assembly process for soil fungal abundant and rare fungal taxa along an elevational gradient emphasized the stochastic process in fungal communities’ assembly, especially for low abundant taxa.