Lean and keen: Microbial activity in soils from the Maritime Antarctic

Hopkins, D. W.; Dennis, Paul G.; Rushton, Steven; Newsham, Kevin K.; O'Donnell, Anthony G.

doi:10.1111/ejss.12957

Cited by 3 publications

(2 citation statements)

References 43 publications

(78 reference statements)

Supporting

Mentioning

Contrasting

Order By: Relevance

“…Annual minimum, mean and maximum temperatures of unchambered soil at 25–30 mm depth are −32, −7, and 19°C ( Misiak et al, 2021 ). The oligotrophic soil has mean organic C and N concentrations of 0.26% and 0.02%, respectively, an average pH value of 7.9, and is arid, with water potential declining to −7 MPa within a month of snowmelt ( Hopkins et al, 2021 ; Misiak et al, 2021 ). Precipitation at Mars Oasis is extremely sparse, with approximately one snow- or rainfall event occurring each year between December and mid February ( Misiak et al, 2021 ).…”

Section: Methodsmentioning

confidence: 99%

Experimental warming increases fungal alpha diversity in an oligotrophic maritime Antarctic soil

Newsham

Misiak²,

Goodall‐Copestake³

et al. 2022

Front. Microbiol.

Self Cite

View full text Add to dashboard Cite

The climate of maritime Antarctica has altered since the 1950s. However, the effects of increased temperature, precipitation and organic carbon and nitrogen availability on the fungal communities inhabiting the barren and oligotrophic fellfield soils that are widespread across the region are poorly understood. Here, we test how warming with open top chambers (OTCs), irrigation and the organic substrates glucose, glycine and tryptone soy broth (TSB) influence a fungal community inhabiting an oligotrophic maritime Antarctic fellfield soil. In contrast with studies in vegetated soils at lower latitudes, OTCs increased fungal community alpha diversity (Simpson’s index and evenness) by 102–142% in unamended soil after 5 years. Conversely, OTCs had few effects on diversity in substrate-amended soils, with their only main effects, in glycine-amended soils, being attributable to an abundance of Pseudogymnoascus. The substrates reduced alpha and beta diversity metrics by 18–63%, altered community composition and elevated soil fungal DNA concentrations by 1–2 orders of magnitude after 5 years. In glycine-amended soil, OTCs decreased DNA concentrations by 57% and increased the relative abundance of the yeast Vishniacozyma by 45-fold. The relative abundance of the yeast Gelidatrema declined by 78% in chambered soil and increased by 1.9-fold in irrigated soil. Fungal DNA concentrations were also halved by irrigation in TSB-amended soils. In support of regional- and continental-scale studies across climatic gradients, the observations indicate that soil fungal alpha diversity in maritime Antarctica will increase as the region warms, but suggest that the accumulation of organic carbon and nitrogen compounds in fellfield soils arising from expanding plant populations are likely, in time, to attenuate the positive effects of warming on diversity.

show abstract

Section: Methodsmentioning

confidence: 99%

Experimental warming increases fungal alpha diversity in an oligotrophic maritime Antarctic soil

Newsham

Misiak²,

Goodall‐Copestake³

et al. 2022

Front. Microbiol.

Self Cite

View full text Add to dashboard Cite

show abstract

“…Warmer temperatures increase the availability of meltwater from permafrost and glaciers, affecting N-cycling by soil microbial communities [ 116 , 121 ]. For instance, warm and wet conditions stimulated microbial activity when glycine and tryptic soy broth were added to a maritime Antarctic soil in the Signy Island [ 122 ], resulting in the increase in both organic and inorganic N. In particular, the input of carbon in Antarctic soils (either through meltwater or other sources) has been shown to significantly change the kinetics of N-cycling, resulting in net N immobilization [ 117 , 118 ] and changes in the N mineralization process [ 108 , 118 , 119 , 122 , 123 ]. Meltwater pulses with C and N addition induced a positive nutrient cycling response in McMurdo Dry Valley soils [ 116 ], but increased water and organic substrate availability led to a loss of prokaryotic taxonomic diversity [ 115 , 124 , 125 ].…”

Section: N Supplementation Experimentsmentioning

confidence: 99%

Microbial Nitrogen Cycling in Antarctic Soils

et al. 2020

View full text Add to dashboard Cite

The Antarctic continent is widely considered to be one of the most hostile biological habitats on Earth. Despite extreme environmental conditions, the ice-free areas of the continent, which constitute some 0.44% of the total continental land area, harbour substantial and diverse communities of macro-organisms and especially microorganisms, particularly in the more “hospitable” maritime regions. In the more extreme non-maritime regions, exemplified by the McMurdo Dry Valleys of South Victoria Land, nutrient cycling and ecosystem servicing processes in soils are largely driven by microbial communities. Nitrogen turnover is a cornerstone of ecosystem servicing. In Antarctic continental soils, specifically those lacking macrophytes, cold-active free-living diazotrophic microorganisms, particularly Cyanobacteria, are keystone taxa. The diazotrophs are complemented by heterotrophic bacterial and archaeal taxa which show the genetic capacity to perform elements of the entire N cycle, including nitrification processes such as the anammox reaction. Here, we review the current literature on nitrogen cycling genes, taxa, processes and rates from studies of Antarctic soils. In particular, we highlight the current gaps in our knowledge of the scale and contribution of these processes in south polar soils as critical data to underpin viable predictions of how such processes may alter under the impacts of future climate change.

show abstract

Highly differentiated soil bacterial communities in Victoria Land macro-areas (Antarctica)

Canini

Consolandi

Camboni

et al. 2021

FEMS Microbiology Ecology

View full text Add to dashboard Cite

Ice-free areas of Victoria Land, in Antarctica, are characterized by different terrestrial ecosystems, that are dominated by microorganisms supporting highly adapted communities. Despite the unique conditions of these ecosystems, reports on their bacterial diversity are still fragmentary. From this perspective, 60 samples from 14 localities were analyzed. These localities were distributed in coastal sites with differently developed biological soil crusts, inner sites in the McMurdo Dry Valleys with soils lacking of plant coverage, and a site called Icarus Camp, with a crust developed on a thin locally weathered substrate of the underlying parent granitic-rock. Bacterial diversity was studied through 16S rRNA metabarcoding sequencing. Communities diversity, composition and the abundance and composition of different taxonomic groups were correlated to soil physicochemical characteristics. Firmicutes, Bacteroidetes, Cyanobacteria and Proteobacteria dominated these communities. Most phyla were mainly driven by soil granulometry, an often disregarded parameter and other abiotic parameters. Bacterial composition differed greatly among the three macrohabitats, each having a distinct bacterial profile. Communities within the two main habitats (coastal and inner ones) were well differentiated from each other as well, therefore depending on site-specific physicochemical characteristics. A core community of the whole samples was observed, mainly represented by Firmicutes and Bacteroidetes.

show abstract

Lean and keen: Microbial activity in soils from the Maritime Antarctic

Cited by 3 publications

References 43 publications

Experimental warming increases fungal alpha diversity in an oligotrophic maritime Antarctic soil

Experimental warming increases fungal alpha diversity in an oligotrophic maritime Antarctic soil

Microbial Nitrogen Cycling in Antarctic Soils

Highly differentiated soil bacterial communities in Victoria Land macro-areas (Antarctica)

Contact Info

Product

Resources

About