A four year survey reveals a coherent pattern between occurrence of fruit bodies and soil amoebae populations for nivicolous myxomycetes

Mathilde Borg Dahl,Christian Schunk,Martin Schnittler,Oleg Shchepin,Yuri K Novozhilov,Annette Menzel

doi:10.1038/s41598-018-30131-3

Abstract

Among soil-inhabiting protists, myxomycetes stand out by their macroscopic fructifications which have allowed studies on their ecology and distribution for more than two hundred years. One of the most distinct ecological guilds in myxomycetes are the nivicolous or “snowbank” myxomycete species, which produce fruit bodies at the edge of melting snowbanks in spring. Relationship between the occurrence of fructifications and myxamoebae remain unknown. In this study we used modern molecular techniques, by direct DNA amplification from soil extracts (NGS metabarcoding) to compare the distribution of soil-inhabiting myxamoebae found in 2016 with fructifications from the same sites collected over the course of four years (2013, 2015–17) along an elevational transect in the northern German Alps. A coherent community composition between fructification and soil myxamoebae, though with species-specific differences in relative abundance, was revealed. Although patterns varied among species, myxamoebae were found at both low and high elevations, whereas fruit bodies were mainly found at higher elevations, likely explained by the presence of a stable and long-lasting snow cover. In addition, a year to year comparison of fructification records support the hypothesis that the abundance of fructifications strongly depends on the onset of snowfall in the previous autumn and the soil temperature regime throughout the winter.

Highlights

Soil protists are a diverse assemblage of basal Eukaryotic lineages[1,2], which play a crucial role in decomposition where they through their predation regulate and stimulate activity of other microbes and influence higher trophic levels and plant growth[3,4,5,6,7,8]
This paper compares a quantitative survey of fruit bodies from a transect of the German northern limestone Alps with a dataset of soil amoebal populations of nivicolous myxomycetes obtained by environmental PCR from the same transect
All but four sequences clustered within the clade forming the respective morphospecies – at this level virtually no contradictions were found between the morphospecies determination and barcoding results (Supplementary S2)

Summary

Introduction

Soil protists are a diverse assemblage of basal Eukaryotic lineages[1,2], which play a crucial role in decomposition where they through their predation regulate and stimulate activity of other microbes and influence higher trophic levels and plant growth[3,4,5,6,7,8]. One of the most distinct ecological guilds in myxomycetes are the nivicolous or “snowbank” species Their specific habitat along the edge of melting snowbanks was first described in 1908 by Meylan[25]. These myxamoebae thrive and multiply in snow-covered soil[26], benefiting from the constant temperatures of 0 to 1 °C maintained by the snowpacks[27]. This paper compares a quantitative survey of fruit bodies (from four years) from a transect of the German northern limestone Alps with a dataset of soil amoebal populations of nivicolous myxomycetes obtained by environmental PCR from the same transect (one year, publication under review[34]). We ask if 1) the occurrence of fructifications reflects that of myxamoebae in soil and 2) if year-to-year variations in fructification records can be explained by winter temperatures and the stability and duration of the snow cover

Methods

Results

Discussion

Conclusion