Soil microbial biomass, activity and community composition along altitudinal gradients in the High Arctic (Billefjorden, Svalbard)

Abstract

Abstract. The unique and fragile High Arctic ecosystems are vulnerable to global climate warming. The elucidation of factors driving microbial distribution and activity in arctic soils is essential for a comprehensive understanding of ecosystem functioning and its response to environmental change. The goals of this study were to investigate microbial biomass and activity, microbial community structure (MCS), and their environmental controls in soils along three elevational transects in the coastal mountains of Billefjorden, central Svalbard. Soils from four different altitudes (25, 275, 525 and 765 m above sea level) were analyzed for a suite of characteristics including temperature regimes, organic matter content, base cation availability, moisture, pH, potential respiration, and microbial biomass and community structure using phospholipid fatty acids (PLFAs). We observed significant spatial heterogeneity of edaphic properties among transects, resulting in transect-specific effects of altitude on most soil parameters. We did not observe any clear elevation pattern in microbial biomass, and microbial activity revealed contrasting elevational patterns between transects. We found relatively large horizontal variability in MCS (i.e., between sites of corresponding elevation in different transects), mainly due to differences in the composition of bacterial PLFAs, but also a systematic altitudinal shift in MCS related to different habitat preferences of fungi and bacteria, which resulted in high fungi-to-bacteria ratios at the most elevated sites. The biological soil crusts on these most elevated, unvegetated sites can host microbial assemblages of a size and activity comparable to those of the arctic tundra ecosystem. The key environmental factors determining horizontal and vertical changes in soil microbial properties were soil pH, organic carbon content, soil moisture and Mg 2+ availability.

How microbial community composition, sorption and simultaneous application of six pharmaceuticals affect their dissipation in soils

“…Phospholipids were eluted with 2 cm 3 methanol and subjected to mild alkaline metanolysis according to Dowling et al (1986) and Oravecz et al (2004). Samples were analyzed on an Agilent Trace 1310 GC (Agilent, Wilmington, Delaware, USA) equipped with a flame ionization detector and a 60 m × 0.32 mm BPX70 × 0.25 μm column (SGE Analytical Science) (Kotas et al, 2018). The results were processed using Chromeleon 7.2.…”

A nematode in the mist: Scottnema lindsayae is the only soil metazoan in remote Antarctic deserts, at greater densities with altitude

“…Similar inconsistencies with altitude were found in microbial communities. Kotas et al (2017) showed that in the Arctic, microbial biomass increases with altitude, but it seems that such responses may be taxon dependent (Gremmen et al 2007;Bryant et al 2008).…”

Distribution of Soil Extracellular Enzymatic, Microbial, and Biological Functions in the C and N-Cycle Pathways Along a Forest Altitudinal Gradient

“…Although altitude may not have a direct impact on soil organic matter (SOM) turnover, it can still influence this process indirectly by shaping soil, climatic, and vegetation conditions (Sierra and Causeret, 2018;Devi and Sherpa, 2019). Climatic conditions (i.e., decreased temperature and humidity) are heavily influenced by altitude, which in turn affects vegetation distribution/composition and alters the quality and quantity of litter/soil characteristics and C loss (Kotas et al, 2018;Quan et al, 2019). Recent studies have documented how changes in climatic conditions and forest canopy composition associated with altitude can affect the litter decomposition rate (Cardelli et al, 2019), soil microbial/enzyme activities (Feng et al, 2019;D'Alò et al, 2021), and nutrient storage in different ways (Bello et al, 2015).…”