Fungal Growth and Biomass Development is Boosted by Plants in Snow-Covered Soil

Abstract

Soil microbial communities follow distinct seasonal cycles which result in drastic changes in processes involving soil nutrient availability. The biomass of fungi has been reported to be highest during winter, but is fungal growth really occurring in frozen soil? And what is the effect of plant cover on biomass formation and on the composition of fungal communities? To answer these questions, we monitored microbial biomass N, ergosterol, and the amount of fungal hyphae during summer and winter in vegetated and unvegetated soils of an alpine primary successional habitat. The winter fungal communities were identified by rDNA ITS clone libraries. Winter soil temperatures ranged between -0.6°C and -0.1°C in snow-covered soil. We found distinct seasonal patterns for all biomass parameters, with highest biomass concentrations during winter in snow-covered soil. The presence of plant cover had a significant positive effect on the amount of biomass in the soil, but the type of plant cover (plant species) was not a significant factor. A mean hyphal ingrowth of 5.6 m g(-1) soil was detected in snow-covered soil during winter, thus clearly proving fungal growth during winter in snow-covered soil. Winter fungal communities had a typical species composition: saprobial fungi were dominating, among them many basidiomycete yeasts. Plant cover had no influence on the composition of winter fungal communities.

Myrmecridium hiemale sp. nov. from snow-covered alpine soil is the first eurypsychrophile in this genus of anamorphic fungi

“…1). Soil characteristics at the site were described in detail by Kuhnert et al (2012). Briefly, the parent material of the soil is mainly neoglacial moraine till (mica slate and granite with local grains of carbonate minerals) and fluvioglacial sands.…”

“…However, little research has focused on the biodiversity of organisms growing in snow-covered soil, and most studies are based on molecular data only (Kuhnert et al, 2012;Zinger et al, 2009). Therefore, we studied fungi growing in snow-covered soil by using a polyphasic approach, integrating selective isolation of fungi actively growing into in-growth mesh bags (Kuhnert et al, 2012), morphological characterization, determination of the temperature range of growth and phylogenetic analysis.…”

“…Mesh bags were buried in snow-covered, unvegetated soil on 28 November 2007 and harvested on 20 February 2008. Soil temperatures at 10 cm depth were constantly slightly below 0 C (À0.61 to À0.16 C) (Kuhnert et al, 2012). Mesh bags were stored at -80 C. Isolation of fungi was carried out on Melin-Norkrams modified medium (MNM), potato dextrose agar (PDA) and synthetic nutrient agar (SNA) (all pH 5.6).…”

Gromochytrium mamkaevae gen. & sp. nov. and two new orders: Gromochytriales and Mesochytriales (Chytridiomycetes)

“…2); its closest relatives are three uncultured clones: one from Lake Koronia in Greece (clone kor_110904_17), another from snow-covered soil in alpine Austria (clone IIN1-34), and one more from a hyposaline soda lake in Kenya, East Africa (Genitsaris et al 2009, Kuhnert et al 2012, Luo et al 2013). Together these sequences form a new phylogenetic group.…”

Temporal variation of Bistorta vivipara‐associated ectomycorrhizal fungal communities in the High Arctic

“…; Kuhnert et al . ). The overall higher ECM fungal richness observed in April may therefore be due to a more even distribution of ECM lineages in April under snow cover conditions, leading to successful amplification of more OTUs.…”