Alpine Snow Algae Microbiome Diversity in the Coast Range of British Columbia

Abstract

Snow algae blooms contain bacteria, fungi, and other microscopic organisms. We surveyed 55 alpine snow algae blooms, collecting a total of 68 samples, from 12 mountains in the Coast Range of British Columbia, Canada. We used microscopy and rDNA metabarcoding to document biodiversity and query species and taxonomic associations. Across all samples, we found 173 algal, 2,739 bacterial, 380 fungal, and 540 protist/animalia operational taxonomic units (OTUs). In a previous study, we reported that most algal species were distributed along an elevational gradient. In the current study, we were surprised to find no corresponding distribution in any other taxa. We also tested the hypothesis that certain bacterial and fungal taxa co-occur with specific algal taxa. However, despite previous evidence that particular genera co-occur, we found no significant correlations between taxa across our 68 samples. Notably, seven bacterial, one fungal, and two cercozoan OTUs were widely distributed across our study regions. Taken together, these data suggest that any mutualisms with algae may not be taxon specific. We also report evidence of snow algae predation by rotifers, tardigrades, springtails, chytrid fungi, and ciliates, establishing the framework for a complex food web.

Snow Algae Blooming Are Benefitable for Microinvertebrates Assemblages (Tardigrada and Rotifera) on the Seasonal Snow Patches in Japan

“…The need for holistic studies on snow and biosphere including microbial activity which change the chemical composition of snow is well acknowledged 7 . Many taxa inhabit the seasonal snow 5,6,16 , however in many cases it is hard to infer which faunal elements are true snow ecosystems element and which randomly feed on snow algae. Herein we showed that tardigrades and rotifers are abundant where snow algae blooming occurred with preferences towards green snow (Chloromonas sp.)…”

“…Although snow patches are important element supporting the functioning of other ecosystems, seasonal snow provide also speci c environments for microorganisms. Despite the harsh conditions of snow surface like a low temperature and high UV irradiation, there are many taxa inhabiting unique snow ecosystems including primary producers (snow algae and cyanobacteria), microbial heterotrophs like fungi 5 , and consumers represented mostly by insects 6 . Activity of microorganisms in seasonal snow could in uence their melting by reduction of snow albedo, change air composition and effects on climate by releasing e.g.…”

“…Snow algae blooming has been shown to in uence melt rates of snow due to reduction of albedo on the snow surface, at the same providing liquid water for further biological processes 13,14 , and act as mediator in nutrient and carbon cycles 7,15 . Potential consumers of algae on snow patches have been also reported 5,6,16 , but without detailed ecological data explaining links between their densities, biomass, sources and seasonality. Although invertebrates are common apex consumers in snow ecosystems, knowledge on their diversity is related mostly to macroinvertebrates in high mountains 17,18 with limited data on microinvertebrates particularly tardigrades and rotifers which are one of the most common faunal groups in polar and high mountain ecosystems 19 .…”

“…Tardigrades and rotifers in snow habitats, although important, are particularly overlooked or just anecdotally recorded 5 .…”

Cysts of the Snow Alga Chloromonas krienitzii (Chlorophyceae) Show Increased Tolerance to Ultraviolet Radiation and Elevated Visible Light

“…Long-lasting, melting snow is an extremophilic habitat for specialised phototrophic eukaryotes (Hoham and Remias, 2020). Cryoflora represents the primary producers in an ecosystem containing heterotrophic members like bacteria, ciliates, mites, rotifers, tardigrades, springtails in combination with fungi like chytrids (Yakimovich et al, 2020). During the melting period, snow algae cause the macroscopic phenomenon of coloured snow.…”