Fungal Communities Along a Small-Scale Elevational Gradient in an Alpine Tundra Are Determined by Soil Carbon Nitrogen Ratios.

Yingying Ni,Congcong Shen,Kaoping Zhang,Teng Yang,Haiyan Chu

doi:10.3389/fmicb.2018.01815

Abstract

Elevational gradients are associated not only with variations in temperature and precipitation, but also with shifts in vegetation types and changes in soil physicochemical properties. While large-scale elevational patterns of soil microbial diversity, such as monotonic declines and hump-shaped models, have been reported, it is unclear whether within-ecosystem elevational distribution patterns exist for soil fungal communities at the small scale. Using Illumina Miseq DNA sequencing, we present a comprehensive analysis of soil fungal diversity and community compositions in an alpine tundra ecosystem at elevations ranging from 2000 to 2500 m on the Changbai Mountain, China. Soil fungal community composition differed among elevations, and the fungal diversity (i.e., species richness and Chao1) increased along elevations. Soil fungal richness was negatively correlated with soil carbon/nitrogen (C/N) ratio, and community composition varied according to the C/N ratio. In addition, the relative abundances of Basidiomycota and Leotiomycetes were similarly negatively correlated with C/N ratio. For functional guilds, our data showed that mycoparasite and foliar epiphyte abundances were also influenced by C/N ratio. These results indicated that soil C/N ratio might be a key factor in determining soil fungal distribution at small-scale elevational gradients.

Highlights

The study of elevational diversity patterns contributes to important insights for developing the general theory of species diversity (Lomolino, 2001)
Soil physicochemical properties including soil pH, soil moisture, dissolved organic carbon (DOC), dissolved organic nitrogen (DON), NO−3 −N, NH+4 −N, total carbon (TC), total nitrogen (TN), and C/N ratio have been described in our previous study (Shen et al, 2015)
Soil C/N ratio, the contents of TC and DOC were significantly negatively correlated with elevation (Supplementary Table S1)

Summary

Introduction

The study of elevational diversity patterns contributes to important insights for developing the general theory of species diversity (Lomolino, 2001). It provides novel perspectives on the potential responses of biological communities and ecosystems to the changing environments (Sundqvist et al, 2013). Some studies on bacterial diversity along elevational gradients have showed a range of microbial responses to increasing elevation, including decreasing (Bryant et al, 2008), Determinants of Tundra Fungal Communities unimodal (Singh et al, 2012), and inconsistent trends (Fierer et al, 2011; Shen et al, 2013; Xu et al, 2014; Wang et al, 2017). A temperature was found to be the strongest predictor of soil fungal diversity in the maritime Antarctic (Newsham et al, 2016)

Methods

Results

Discussion

Conclusion