Bacterial and fungal communities in boreal forest soil are insensitive to changes in snow cover conditions

Abstract

The northern regions are experiencing considerable changes in winter climate leading to more frequent warm periods, rain-on-snow events and reduced snow pack diminishing the insulation properties of snow cover and increasing soil frost and freeze-thaw cycles. In this study, we investigated how the lack of snow cover, formation of ice encasement and snow compaction affect the size, structure and activities of soil bacterial and fungal communities. Contrary to our hypotheses, snow manipulation treatments over one winter had limited influence on microbial community structure, bacterial or fungal copy numbers or enzyme activities. However, microbial community structure and activities shifted seasonally among soils sampled before snow melt, in early and late growing season and seemed driven by substrate availability. Bacterial and fungal communities were dominated by stress-resistant taxa such as the orders Acidobacteriales, Chaetothyriales and Helotiales that are likely adapted to adverse winter conditions. This study indicated that microbial communities in acidic northern boreal forest soil may be insensitive to direct effects of changing snow cover. However, in long term, the detrimental effects of increased ice and frost to plant roots may alter plant derived carbon and nutrient pools to the soil likely leading to stronger microbial responses.

Immediate and legacy effects of snow exclusion on soil fungal diversity and community composition

“…Both phylum Ascomycota and Basidiomycota were the two dominant phyla in the study site. Similar findings are observed in other cold ecosystems, such as glacier ecosystems, alpine meadows and boreal forests (Yao et al 2013;Antony et al 2016;Gao and Yang 2016;Chen et al 2017aChen et al , 2017bHan et al 2017;Männistö et al 2018). Hypocreales, Archaeorhizomycetales and Eurotiales were the dominant orders in the phylum Ascomycota.…”

“…As stated above, there might be similar common soil fungal communities among different snowy environments, indicating these fungal communities have an extensive adaptability. A growing number of studies have revealed that snow cover changes leaded to significant impacts on soil fungal community composition and diversity in cold ecosystems (Mundra et al 2016;Semenova et al 2016;Männistö et al 2018). For example, deeper snow cover decreased saprotrophic fungi but increased ECM fungi richness (Mundra et al 2016).…”

Immediate and legacy effects of snow exclusion on soil fungal diversity and community composition

“…In addition, increased snow cover significantly altered the composition of soil fungal communities in arctic tundra (Morgado et al 2016;Semenova et al 2016). In contrast, the lack of snow cover resulted in the slight effects on soil fungal community structure and activity in a boreal coniferous forest (Minna et al 2018). Our results are consistent with the observations found in alpine tundra (Zinger et al 2009) and in temperate and boreal forest ecosystems (Gao et al 2018), which indicated that snow cover change did not induce significant changes in soil fungal diversity and communities composition.…”

“…A growing number of studies have revealed that snow cover changes leaded to significant impacts on soil fungal community composition and diversity in cold ecosystems (Mundra et al 2016;Semenova et al 2016;Minna et al 2018). For example, deeper snow cover decreased saprotrophic fungi but increased ECM fungi richness (Mundra et al 2016).…”

Estimation of Fungal Diversity and Identification of Major Abiotic Drivers Influencing Fungal Richness and Communities in Northern Temperate and Boreal Quebec Forests

“…The three most frequent orders that characterized our regions were the Agaricales, Helotiales, and Russulales (Figure 2). These three groups are generally dominant in boreal forest [11,[53][54][55]. The genus Lactarius and Russula, from the order Russulales, are abundant and diverse ectomycorrhizal fungi in northern forests, especially because there are host generalists [14,56,57].…”