Alpine soil microbial ecology in a changing world

Abstract

Climate change has a disproportionally large impact on alpine soil ecosystems, leading to pronounced changes in soil microbial diversity and function associated with effects on biogeochemical processes at the local and supraregional scales. However, due to restricted accessibility, high-altitude soils remain largely understudied and a considerable heterogeneity hampers the comparability of different alpine studies. Here, we highlight differences and similarities between alpine and arctic ecosystems, and we discuss the impact of climatic variables and associated vegetation and soil properties on microbial ecology. We consider how microbial alpha-diversity, community structures and function change along altitudinal gradients and with other topographic features such as slope aspect. In addition, we focus on alpine permafrost soils, harboring a surprisingly large unknown microbial diversity and on microbial succession along glacier forefield chronosequences constituting the most thoroughly studied alpine habitat. Finally, highlighting experimental approaches, we present climate change studies showing shifts in microbial community structures and function in response to warming and altered moisture, interestingly with some contradiction. Collectively, despite harsh environmental conditions, many specially adapted microorganisms are able to thrive in alpine environments. Their community structures strongly correlate with climatic, vegetation and soil properties and thus closely mirror the complexity and small-scale heterogeneity of alpine soils.

The “Plastisphere” of Biodegradable Plastics Is Characterized by Specific Microbial Taxa of Alpine and Arctic Soils

“…Overall, the microbial communities of the plastisphere and bulk soil were characterized by taxonomic groups commonly observed in Arctic and alpine soils (Frey et al, 2016;Rime et al, 2016;Donhauser and Frey, 2018;Malard and Pearce, 2018). Only few phyla of this endemic microbiome showed an altered relative abundance in the plastisphere.…”

Carbon dioxide emissions from periglacial patterned ground under changing permafrost conditions and shrub encroachment in an alpine landscape, Jotunheimen, Norway

“…For example, an increase of 1,000 m in altitude provides a comparable change in temperature as travelling 1,000 km towards higher latitudes. 53,54 This study similarly uses an altitudinal transect as a proxy for future climate warming. 55,56 We identified a number of variables that are likely to affect R e in this alpine environment and estimated how their control over R e changed across an altitudinal transect.…”

“…The remaining three proxies (Elongation, Isotropy and average dip angle) are less significant ( Figure 5 and Table 2) in explaining the variance in R e . 53 Both have a strong relationship with soil respiration (R s ). [64][65][66] While soil temperature has often been identified as the main controlling factor of R s , 64,65,67 this was not the case in our study.…”

“…For example, increased soil moisture is predicted to affect soil and root respiration, especially in dry Arctic regions. 6,66 Concurrently, higher temperatures could create a more favorable environment for soil microbes in alpine regions, with the capacity to speed up carbon and nitrogen cycling, 53 leading to net losses from these ecosystems. 88 Furthermore, warming conditions facilitate the expansion of deciduous shrubs relative to other tundra vegetation, such as graminoids, bryophytes, and lichens.…”

Microbial communities across a hillslope-riparian transect shaped by proximity to the stream, groundwater table, and weathered bedrock

“…Runoff and groundwater transport solutes along the elevation gradient and into aquifers, rivers and 91 lakes. Soils ay hillslopes and floodplains, and in general, harbor considerable microbial diversity 92 (Rime et al, 2014;Frey et al, 2016;Donhauser and Frey, 2018). Most studies of microbial 93 communities in mountainous soils have been concerned with the microbial community structure 94 across different climate zones on the mountain slopes (Djukic et al, 2010;Zhang et al, 2013;Xu 95 et al, 2014;Klimek et al, 2015;Bardelli et al, 2017).…”