Kevin K Newsham

Kevin K Newsham
British Antarctic Survey | BAS

About

177
Publications
23,507
Reads
How we measure 'reads'
A 'read' is counted each time someone views a publication summary (such as the title, abstract, and list of authors), clicks on a figure, or views or downloads the full-text. Learn more
7,130
Citations
Citations since 2017
29 Research Items
2848 Citations
20172018201920202021202220230100200300400500
20172018201920202021202220230100200300400500
20172018201920202021202220230100200300400500
20172018201920202021202220230100200300400500

Publications

Publications (177)
Preprint
Full-text available
Fungi play pivotal roles in ecosystem functioning, but little is known about their global patterns of diversity, endemicity, vulnerability to global change drivers and conservation priority areas. We applied the high-resolution PacBio sequencing technique to identify fungi based on a long DNA marker that revealed a high proportion of hitherto unkno...
Article
Full-text available
Fungi are highly important biotic components of terrestrial ecosystems, but we still have a very limited understanding about their diversity and distribution. This data article releases a global soil fungal dataset of the Global Soil Mycobiome consortium (GSMc) to boost further research in fungal diversity, biogeography and macroecology. The datase...
Article
Full-text available
Mycothalli, symbioses between liverworts and soil fungi, have not previously been recorded in the Arctic. Here, 13 species of leafy liverwort from west Spitsbergen in the High Arctic are examined for the symbiosis using epifluorescence microscopy and sequencing of fungal ribosomal (r)RNA genes amplified from plant tissues. Microscopy showed that in...
Article
Full-text available
The growing problem of antibiotic resistance has led to the exploration of uncultured bacteria as potential sources of new antimicrobials. PCR amplicon analyses and short-read sequencing studies of samples from different environments have reported evidence of high biosynthetic gene cluster (BGC) diversity in metagenomes, indicating their potential...
Article
Previous studies have shown changes to the frequencies of hyphal coils and other fungal structures in leafy liverwort tissues across latitudinal transects through Antarctica. Although suggestive of a role of temperature in determining the frequencies of fungal structures, these studies could not exclude the possibility that other factors which alte...
Article
Full-text available
We report a metabarcoding study documenting the fungal taxa in 29 barren fellfield soils sampled from along a 1,650 km transect encompassing almost the entire maritime Antarctic (60–72°S) and the environmental factors structuring the richness, relative abundance, and taxonomic composition of three guilds and growth forms. The richness of the lichen...
Article
Full-text available
We report a previously undescribed member of the Helotiales that is superabundant in soils at two maritime Antarctic islands under Antarctic Hairgrass ( Deschampsia antarctica Desv.). High throughput sequencing showed that up to 92% of DNA reads, and 68% of RNA reads, in soils from the islands were accounted for by the fungus. Sequencing of the lar...
Preprint
Full-text available
The growing problem of antibiotic resistance has led to the exploration of uncultured bacteria as potential sources of new antimicrobials. PCR amplicon analyses and short-read sequencing studies of samples from different environments have reported evidence of high biosynthetic gene cluster (BGC) diversity in metagenomes. However, few complete BGCs...
Article
Full-text available
Temperatures approaching or exceeding 20 °C have been measured during summer in polar regions at the surfaces of barren fellfield soils under cloudless skies around solar noon. However, despite the upper temperature limit for the growth of cold‐adapted microbes – which are abundant in polar soils and have pivotal roles in nutrient cycling – typical...
Article
Despite nematodes routinely being the most frequent soil- and bryophyte-associated animals in maritime Antarctica, there is a lack of clarity about the influence of warming on their populations in the region. Here, we report the results of a field experiment on Adelaide Island that tested the effects of warming with open-top chambers (OTCs) for 37...
Article
Full-text available
In this review, we examine the functional roles of microbial symbionts in plant tolerance to cold and freezing stresses. The impacts of symbionts on antioxidant activity, hormonal signaling and host osmotic balance are described, including the effects of the bacterial endosymbionts Burkholderia, Pseudomonas and Azospirillum on photosynthesis and th...
Article
Full-text available
Aim Antarctica's remote and extreme terrestrial environments are inhabited by only two species of native vascular plants. We assessed genetic connectivity amongst Antarctic and South American populations of one of these species, Colobanthus quitensis, to determine its origin and age in Antarctica. Location Maritime Antarctic, sub‐Antarctic islands...
Article
The soils of the Maritime and sub‐Antarctic experience extreme environmental conditions but nonetheless host biological communities that can survive low temperatures, limited water availability and short day lengths or even the complete absence of solar radiation during the winter. We determined the soil organic carbon (SOC) and total nitrogen (N),...
Article
Full-text available
In contrast to the situation in plants inhabiting most of the world’s ecosystems, mycorrhizal fungi are usually absent from roots of the only two native vascular plant species of maritime Antarctica, Deschampsia antarctica and Colobanthus quitensis. Instead, a range of ascomycete fungi, termed dark septate endophytes (DSEs), frequently colonise the...
Article
Full-text available
A resumption of climate warming in maritime Antarctica, arising from continued greenhouse gas emissions to the atmosphere, is predicted to lead to further expansions of plant populations across the region, with consequent increases in nutrient inputs to soils. Here, we test the main and interactive effects of warming, applied with open top chambers...
Article
Full-text available
We report a space-for-time substitution study predicting the impacts of climate change on vegetated maritime Antarctic soils. Analyses of soils from under Deschampsia antarctica sampled from three islands along a 2200 km climatic gradient indicated that those from sub-Antarctica had higher moisture, organic matter and carbon (C) concentrations, mor...
Article
Full-text available
Background The emergence of antibiotic-resistant pathogens has created an urgent need for novel antimicrobial treatments. Advances in next-generation sequencing have opened new frontiers for discovery programmes for natural products allowing the exploitation of a larger fraction of the microbial community. Polyketide (PK) and non-ribosomal pepetide...
Data
Fig. S1 Alpha diversity rarefaction plots. Fig. S2 Snow algae community biomass and cell counts. Fig. S3 Representative ultraviolet–visible absorption spectra of solvent ethanol extracts from green‐ or red‐dominant snow algae communities. Fig. S4 Pigment content of snow algae blooms. Fig. S5 Alpha diversity boxplots. Fig. S6 Screen shots of be...
Article
Full-text available
Terrestrial ecosystems in the maritime Antarctic experienced rapid warming during the latter half of the 20th century. While warming ceased at the turn of the millennium, significant increases in air temperature are expected later this century, with predicted positive effects on soil fungal diversity, plant growth and ecosystem productivity. Here,...
Article
Full-text available
Snow algae are found in snowfields across cold regions of the planet, forming highly visible red and green patches below and on the snow surface. In Antarctica, they contribute significantly to terrestrial net primary productivity due to the paucity of land plants, but our knowledge of these communities is limited. Here we provide the first descrip...
Article
Full-text available
Our understanding of the diversity and community dynamics of soil fungi has increased greatly through the use of DNA‐based identification. Community characterisation of metabolically active communities via RNA sequencing has previously revealed differences between ‘active’ and ‘total’ fungal communities, which may be influenced by the persistence o...
Article
Soil microbial communities in the Arctic, one of the most rapidly warming regions on Earth, play an important role in a range of ecological processes. This report describes initial studies of natural soil bacterial diversity at a High Arctic site on Svalbard, as part of a long-term field environmental manipulation study. The impact of increased soi...
Article
Full-text available
The harsh climatic conditions and low levels of human activity in Antarctica, relative to other regions, means few non-native species have established. However, the risk of introductions is becoming greater as human activity increases. Non-native microorganisms can be imported to Antarctica in association with fresh food, cargo and personal clothin...
Article
Full-text available
Different organic compounds have distinct residence times in soil and are degraded by specific taxa of saprotrophic fungi. It hence follows that specific fungal taxa should respire carbon of different ages from these compounds to the atmosphere. Here, we test whether this is the case by radiocarbon (14C) dating CO2 evolved from two gamma radiation-...
Poster
Full-text available
Whilst it has been established that plants acquire amino acids in the rhizosphere, the effects of competition from soil microbes & their rapid amino acid turnover remain poorly-characterised.However, conventional pulse labelling techniques may be unrepresentative of nutrient flows in situ. Therefore, microdialysis may offer the potential to continu...
Article
A previous study of 76 plant species on Spitsbergen in the High Arctic concluded that structures resembling arbuscular mycorrhizas were absent from roots. Here, we report a survey examining the roots of 13 grass and forb species collected from 12 sites on the island for arbuscular mycorrhizal (AM) colonisation. Of the 102 individuals collected, we...
Article
Antarctica's extreme environment and geographical isolation offers a useful platform for testing the relative roles of environmental selection and dispersal barriers influencing fungal communities. The former process should lead to convergence in community composition with other cold environments, such as those in the Arctic. Alternatively, dispers...
Article
Gelifluction, thixotropy and yield stress were measured from < 5 g soil samples taken from Signy, Alectoria, Greenwich, Wiencke and Livingston islands in the maritime Antarctic using a temperature-controlled rotational rheometer. The small sample size that this method permitted is compatible with sampling from sensitive sample locations. An oscilla...
Article
Soil fungi have pivotal ecological roles as decomposers, pathogens and symbionts. Alterations to their diversity arising from climate change could have substantial effects on ecosystems, particularly those undergoing rapid warming that contain few species. Here, we report a study using pyrosequencing to assess fungal diversity in 29 soils sampled f...
Article
Full-text available
The ever increasing microbial resistome means there is an urgent need for new antibiotics. Metagenomics is an underexploited tool in the field of drug discovery. In this study we aimed to produce a new updated assay for the discovery of biosynthetic gene clusters encoding bioactive secondary metabolites. PCR assays targeting the polyketide synthase...
Article
Understanding relationships between environmental changes and soil microbial respiration is critical for predicting changes in soil organic carbon (SOC) fluxes and content. The maritime Antarctic is experiencing one of the fastest rates of warming in the world and is therefore a key location to examine the effect of temperature on SOC mineralizatio...
Article
Full-text available
l-isomeric amino acids and oligopeptides are thought to represent a key nitrogen (N) source for plants and soil microorganisms, bypassing the need to take up inorganic N, whilst self-cycling of d-enantiomers within peptidoglycan-containing bacteria may provide a further short circuit within the N cycle. Here we use stable isotope profiling (SIP) to...
Article
Forty-four herbarium specimens of the hepatic Barbilophozia hatcheri, collected from across the entire range of the species in Antarctica (54–68 °S), were examined for fungal colonisation. Mycothalli, consisting of hyaline hyphae in rhizoids or hyphal coils in rhizoid bases and stem medullary cells, were present in 42 specimens. The frequencies of...
Article
Full-text available
We have investigated how the microbially-driven processes of carbon (C) mineralization (respiration) and nitrogen (N) mineralization/immobilization in a soil from the northern Maritime Antarctic respond to differences in water availability (20% and 80% water-holding capacity) and temperature (5 degrees C and 15 degrees C) in the presence and absenc...
Conference Paper
Applications of compound-specific mass spectrometry to investigate microbial dynamics in Antarctic soils? Claire A Horrocks1, Jennifer A.J. Dungait1, Filipa Cox2, Kevin K. Newsham3, Roland Bol4, Clare H. Robinson2 1Sustainable Soils and Grassland Systems Department, Rothamsted Research-North Wyke, Okehampton, Devon EX20 2SB, UK 2School of Earth,...
Chapter
Antarctica is not a single ecological model. Substantial differences in the temperature, precipitation (which combine to affect the available water) and radiation determine the distribution and the habit of primary producers that in turn structure the trophic. Because terrestrial primary production is operating at environmental extremes in some par...
Article
We investigated the effects of increased soil temperature, water and nutrient availability on soil bacterial communities at Wynn Knolls on Signy Island (60 °S) in the northern maritime Antarctic and at Mars Oasis (71 °S) in the southern maritime Antarctic. After 10–12 months, analyses of the concentrations of ester linked fatty acids (ELFAs) in soi...
Article
Full-text available
Our current understanding of Antarctic soils is derived from direct culture on selective media, biodiversity studies based on clone library construction and analysis, quantitative PCR amplification of specific gene sequences and the application of generic microarrays for microbial community analysis. Here, we investigated the biodiversity and funct...
Article
We investigated the relationships between fungal community composition, latitude and a range of physicochemical parameters in 58 soils sampled from a 2370 km latitudinal gradient between South Georgia (54°S, 38°W) in the sub-Antarctic and Mars Oasis (72°S, 68°W) on Alexander Island in the southern maritime Antarctic. Our study, which is based on ap...
Article
Snow moulds are fungi and fungal-like microbes that occur frequently as pathogens of moss and vascular plant species in the Arctic and Antarctic, chiefly in maritime areas with permanent snow cover for several months of each year. Here, we review the environments inhabited by polar snow moulds, their distribution and the macroscopic features of inf...
Chapter
This book with twenty-eight chapters including the concluding remarks discusses the range of extreme environments that exist on earth, and the organisms that live in them and their evolutionary implications. Particularly, the book explores the following extreme environments: polar marine and terrestrial environments; high altitude and latitude as w...
Article
• Dark septate endophytes (DSE) frequently colonize roots in the natural environment, but the effects of these fungi on plants are obscure, with previous studies indicating negative, neutral or positive effects on plant performance. • In order to reach a consensus for how DSE influence plant performance, meta-analyses were performed on data from 18...
Article
Full-text available
Nitrogen is a key regulator of primary productivity in many terrestrial ecosystems. Historically, only inorganic N (NH4+ and NO3-) and L-amino acids have been considered to be important to the N nutrition of terrestrial plants. However, amino acids are also present in soil as small peptides and in D-enantiomeric form. We compared the uptake and ass...
Article
Previous studies have shown the leafy liverwort Cephaloziella varians to associate consistently with fungi, typically the ericoid mycorrhizal symbiont Rhizoscyphus ericae, across a wide latitudinal gradient in the maritime and sub-Antarctic. Hitherto, however, there are no quantitative data on the intensity of colonisation of C. varians by fungal s...
Article
Full-text available
For the past 50 years there has been rapid warming in the maritime Antarctic, with concurrent, and probably temperature-mediated, proliferation of the two native plants, Antarctic pearlwort (Colobanthus quitensis) and especially Antarctic hair grass (Deschampsia antarctica). In many terrestrial ecosystems at high latitudes, nitrogen (N) supply regu...
Article
Full-text available
Solute yields, laboratory dissolution data and both chemical and isotopic markers of rock weathering reactions are used to characterise the biogeochemistry of glacial meltwaters draining a maritime Antarctic glacier. We find that delayed flowpaths through ice-marginal talus and moraine sediments are critical for the acquisition of solute from rock...
Article
The biology and ecology of Cephaloziella varians, the most widespread and abundant liverwort in Antarctica, are reviewed. A description of the species is given, together with information on its geographical distribution, reproduction, habitats, associated organisms and responses to environmental stresses. Characteristics of its photosynthetic physi...
Article
Full-text available
The Antarctic climate system varies on timescales from orbital, through millennial to sub-annual, and is closely coupled to other parts of the global climate system. We review these variations from the perspective of the geological and glaciological records and the recent historical period from which we have instrumental data (the last 50 years). W...
Article
Bacterial community composition was determined by culture-independent PCR-based methods in two soils differing markedly in their water, C, N and P contents sampled from Mars Oasis on Alexander Island, western Antarctic Peninsula. 16S rRNA sequences of the phyla Actinobacteria, Cyanobacteria, α-Proteobacteria and Acidobacteria were commonly (> 8% fr...
Article
We report a meta-analysis of data from 34 field studies into the effects of ultraviolet B (UVB) radiation on Arctic and Antarctic bryophytes and angiosperms. The studies measured plant responses to decreases in UVB radiation under screens, natural fluctuations in UVB irradiance or increases in UVB radiation applied from fluorescent UV lamps. Exposu...
Article
Although dark septate fungal endophytes (DSE) occur widely in association with plant roots in cold-stressed habitats, little is known of the taxonomic status of DSE in Antarctica. Here we investigate the phylogenetic affinities of DSE colonising the roots of Colobanthus quitensis and Deschampsia antarctica, the two maritime Antarctic vascular plant...
Article
The leafy liverwort Lophozia excisa, which is colonised by basidiomycete fungi in other biomes and which evidence suggests may be colonised by mycorrhizal fungi in Antarctica, was sampled from Léonie Island in the southern maritime Antarctic (67 degrees 36' S, 68 degrees 21' W). Microscopic examination of plants indicated that fungal hyphae colonis...
Article
The effects of elevated UV-B (280–315 nm) radiation on the long-term decomposition of Quercus robur leaf litter were assessed at an outdoor facility in the UK by exposing saplings to elevated UV-B radiation (corresponding to a 30% increase above the ambient level of erythemally weighted UV-B, equivalent to that resulting from a c. 18% reduction in...
Article
Populations of the two native Antarctic vascular plant species (Deschampsia antarctica and Colobanthus quitensis) have expanded rapidly in recent decades, yet little is known about the effects of these expansions on soil nutrient cycling. We measured the concentrations of dissolved organic carbon (DOC) and nitrogen (DON), amino acids and inorganic...
Article
Fungi with dematiaceous septate hyphae, termed dark septate endophytes (DSE), are common in plant roots, particularly in cold-stressed habitats, but their effects on their host plants remain obscure. Here, we report a study that assessed the effects of six DSE on the growth and nutrient balance of Deschampsia antarctica when plants were supplied wi...
Article
PCR amplification of ITS1-5.8S-ITS2 regions of rDNA followed by cloning was used to determine the fungi present in soil from three sites at Mars Oasis in the southern maritime Antarctic. The soils sampled were adjacent to, or distant from, a meltwater pond, and had moisture contents of 8 %, 3.6 % and 2.5 %. Sequences bearing close similarity to Chy...
Article
We quantified the metabolic cost to the Antarctic leafy liverwort Cephaloziella varians of responding to an abrupt increase in ultraviolet B (UVB) radiation exposure in the natural environment at Rothera Point on the western Antarctic Peninsula (67 °34′S, 68 °07′W). The liverwort was protected from exposure to UVB radiation for 44 days with screens...
Article
Full-text available
1] Understanding and accurately predicting the fate of carbon and nitrogen in the terrestrial biosphere remains a central goal in ecosystem science. Amino acids represent a key pool of C and N in soil, and their availability to plants and microorganisms has been implicated as a major driver in regulating ecosystem functioning. Because of potential...
Article
We review the distributions and functions of mycorrhizas and dark septate root endophytes in polar regions. Arbuscular mycorrhizas (AM) are present in the Arctic and Antarctic to 82 °N and 63 °S, respectively, with fine endophyte being the dominant form of AM in roots at higher latitudes. Ecto- (ECM) and ericoid (ERM) mycorrhizas both occur in the...
Article
Full-text available
The instrumental period began with the first voyages to the Southern Ocean during the Seventeenth and Eighteenth centuries when scientists such as Edmund Halley made observations of quantities such as geomagnetism. During the early voyages information was collected on the meteorological conditions across the Southern Ocean, ocean conditions, the se...
Article
The pathogenicity of an isolate of a Pythium species from Signy Island in the South Orkney Islands was tested against the Antarctic hairgrass Deschampsia antarctica. The isolate was found to infect plants at 8ºC and to cause foliar and root symptoms similar to those seen in other Pythium infections in grasses. Analysis of ribosomal RNA sequences pl...
Article
The two native Antarctic vascular plant species, Colobanthus quitensis and Deschampsia antarctica, were sampled from 15 points along a 1480 km latitudinal transect from South Georgia (54°S, 36°W) through to the Léonie Islands on the western Antarctic Peninsula (67°S, 68°W). Roots of plants were cleared and stained and fungal structures recorded. Th...
Article
The effects of u. v.-B radiation (280–315 nm) on the fungi occurring on the lammas leaves of pedunculate oak (Quercus robur L.) were examined using saplings that were exposed at an outdoor facility to supplemental levels of u. v.-B radiation under treatment arrays of cellulose diacetate-filtered fluorescent lamps, which also produce u. v.-A radiati...
Article
Although soil-borne bacteria represent the world's greatest source of biological diversity, it is not well understood whether extreme environmental conditions, such as those found in Antarctic habitats, result in reduced soil-borne microbial diversity. To address this issue, patterns of bacterial diversity were studied in soils sampled along a > 32...
Article
Full-text available
We measured the responses of pigments and chlorophyll a fluorescence parameters of the Antarctic leafy liverwort Cephaloziella varians to snowmelt during austral spring 2005 at Rothera Point on the western Antarctic Peninsula. Although no changes to the concentrations of UV-B photoprotective pigments were detected during snowmelt, chlorophyll and c...