Abstract:The historic expedition huts located in the Ross Sea Region of the Antarctic and the thousands of artifacts left behind by the early explorers represent important cultural heritage from the "Heroic Era" of Polar exploration. The hut at Cape Royds built by Ernest Shackleton and members of the 1907-1908 British Antarctic Expedition has survived the extreme Antarctic environment for over 100 years, but recent studies have shown many forms of deterioration are causing serious problems, and microbial degradation is… Show more
“…That these were common to soils but not to rocky niches offers further evidence that they have been selected for on this basis, because rocky niches are not reservoirs for the "legacy" carbon that is known to endure in Antarctic soils (4). Our results of lignin-like degradative pathways are supported by the findings of wood-degrading fungi in a wide variety of Antarctic soils (20,61,62). A link has been suggested between these saprophytic fungi and those found in the fossil record of the Triassic and Jurassic forests of Antarctica (61).…”
Section: Discussionsupporting
confidence: 78%
“…A link has been suggested between these saprophytic fungi and those found in the fossil record of the Triassic and Jurassic forests of Antarctica (61). Fungi are notorious contaminants especially on imported materials and around sites of human activity and the difficulty of discerning transient/introduced vs. indigenous and endemic organisms and their input to the environment is acknowledged, although indigenous and not exotic fungi dominate on imported wood (62). The structural similarities between lignins and other naturally occurring complex organics and many xenobiotic compounds led us to propose that because of the presence of these fungi, Antarctic soils may possess an innate ability to respond to future pollution threats from these compounds (38).…”
The McMurdo Dry Valleys are the largest ice-free region in Antarctica and are critically at risk from climate change. The terrestrial landscape is dominated by oligotrophic mineral soils and extensive exposed rocky surfaces where biota are largely restricted to microbial communities, although their ability to perform the majority of geobiological processes has remained largely uncharacterized. Here, we identified functional traits that drive microbial survival and community assembly, using a metagenomic approach with GeoChip-based functional gene arrays to establish metabolic capabilities in communities inhabiting soil and rock surface niches in McKelvey Valley. Major pathways in primary metabolism were identified, indicating significant plasticity in autotrophic, heterotrophic, and diazotrophic strategies supporting microbial communities. This represents a major advance beyond biodiversity surveys in that we have now identified how putative functional ecology drives microbial community assembly. Significant differences were apparent between open soil, hypolithic, chasmoendolithic, and cryptoendolithic communities. A suite of previously unappreciated Antarctic microbial stress response pathways, thermal, osmotic, and nutrient limitation responses were identified and related to environmental stressors, offering tangible clues to the mechanisms behind the enduring success of microorganisms in this seemingly inhospitable terrain. Rocky substrates exposed to larger fluctuations in environmental stress supported greater functional diversity in stress-response pathways than soils. Soils comprised a unique reservoir of genes involved in transformation of organic hydrocarbons and lignin-like degradative pathways. This has major implications for the evolutionary origin of the organisms, turnover of recalcitrant substrates in Antarctic soils, and predicting future responses to anthropogenic pollution.
“…That these were common to soils but not to rocky niches offers further evidence that they have been selected for on this basis, because rocky niches are not reservoirs for the "legacy" carbon that is known to endure in Antarctic soils (4). Our results of lignin-like degradative pathways are supported by the findings of wood-degrading fungi in a wide variety of Antarctic soils (20,61,62). A link has been suggested between these saprophytic fungi and those found in the fossil record of the Triassic and Jurassic forests of Antarctica (61).…”
Section: Discussionsupporting
confidence: 78%
“…A link has been suggested between these saprophytic fungi and those found in the fossil record of the Triassic and Jurassic forests of Antarctica (61). Fungi are notorious contaminants especially on imported materials and around sites of human activity and the difficulty of discerning transient/introduced vs. indigenous and endemic organisms and their input to the environment is acknowledged, although indigenous and not exotic fungi dominate on imported wood (62). The structural similarities between lignins and other naturally occurring complex organics and many xenobiotic compounds led us to propose that because of the presence of these fungi, Antarctic soils may possess an innate ability to respond to future pollution threats from these compounds (38).…”
The McMurdo Dry Valleys are the largest ice-free region in Antarctica and are critically at risk from climate change. The terrestrial landscape is dominated by oligotrophic mineral soils and extensive exposed rocky surfaces where biota are largely restricted to microbial communities, although their ability to perform the majority of geobiological processes has remained largely uncharacterized. Here, we identified functional traits that drive microbial survival and community assembly, using a metagenomic approach with GeoChip-based functional gene arrays to establish metabolic capabilities in communities inhabiting soil and rock surface niches in McKelvey Valley. Major pathways in primary metabolism were identified, indicating significant plasticity in autotrophic, heterotrophic, and diazotrophic strategies supporting microbial communities. This represents a major advance beyond biodiversity surveys in that we have now identified how putative functional ecology drives microbial community assembly. Significant differences were apparent between open soil, hypolithic, chasmoendolithic, and cryptoendolithic communities. A suite of previously unappreciated Antarctic microbial stress response pathways, thermal, osmotic, and nutrient limitation responses were identified and related to environmental stressors, offering tangible clues to the mechanisms behind the enduring success of microorganisms in this seemingly inhospitable terrain. Rocky substrates exposed to larger fluctuations in environmental stress supported greater functional diversity in stress-response pathways than soils. Soils comprised a unique reservoir of genes involved in transformation of organic hydrocarbons and lignin-like degradative pathways. This has major implications for the evolutionary origin of the organisms, turnover of recalcitrant substrates in Antarctic soils, and predicting future responses to anthropogenic pollution.
“…Blanchette et al (2004) first reported an unusual form of soft rot decay caused by Cadophora species which can cause degradation of the historic huts and artefacts. This type of decay has subsequently been found to be prevalent in historic woods and in soils from the immediate vicinity of the huts at many Antarctic locations and variety of filamentous fungi and yeasts such as Cadophora, Cladosporium, Cryptococcus and Geomyces species were discovered with a high frequency (Arenz et al 2006; Arenz and Blanchette 2009; Blanchette et al 2010). Although there are few woody plants on the Antarctic continent, researches provide strong evidence that Antarctic fungi are able to colonise and degrade-introduced wood and other organic materials (Blanchette et al 2004, 2010).…”
Section: Cold-adapted Fungi and Their Living Strategiesmentioning
confidence: 99%
“…This type of decay has subsequently been found to be prevalent in historic woods and in soils from the immediate vicinity of the huts at many Antarctic locations and variety of filamentous fungi and yeasts such as Cadophora, Cladosporium, Cryptococcus and Geomyces species were discovered with a high frequency (Arenz et al 2006; Arenz and Blanchette 2009; Blanchette et al 2010). Although there are few woody plants on the Antarctic continent, researches provide strong evidence that Antarctic fungi are able to colonise and degrade-introduced wood and other organic materials (Blanchette et al 2004, 2010). Held et al (2005) found that Antarctic summer above 0°C and 75% relative humidity occurred for many weeks, which are conducive for fungal growing inside the historic huts on Ross Island.…”
Section: Cold-adapted Fungi and Their Living Strategiesmentioning
confidence: 99%
“…and Pseudeurotium desertorum dominated the air environments within the huts and fungal spores are widespread particularly in the interiors of the huts (Duncan et al 2010). Blanchette et al (2010) reported that large numbers of degradative fungi colonised the exterior wood of Shackleton’s Cape Royds hut, presumably due to large carbon and nutrient input from the historic materials as well as introductions from the penguin colony nearby. Both culture-dependent and culture-independent methods demonstrated that low temperature may not adversely affect these fungal species unless they were out-competed by new arrivals or unfavourable changes in ecosystem domination occurred (Farrell et al 2011).…”
Section: Cold-adapted Fungi and Their Living Strategiesmentioning
Our planet is dominant with cold environments that harbour enormously diverse cold-adapted fungi comprising representatives of all phyla. Investigation based on culture-dependent and independent methods has demonstrated that cold-adapted fungi are cosmopolitan and occur in diverse habitants and substrates. They live as saprobes, symbionts, plant and animal parasites and pathogens to perform crucial functions in different ecosystems. Pseudogymnoascus destructans caused bat white-nose syndrome and Ophiocordyceps sinensis as Chinese medicine are the representative species that have significantly ecological and economic significance. Adaptation to cold niches has made this group of fungi a fascinating resource for the discovery of novel enzymes and secondary metabolites for biotechnological and pharmaceutical uses. This review provides the current understanding of living strategy and ecological functions of cold-adapted fungi, with particular emphasis on how those fungi overcome the extreme low temperature and perform their ecological function.
Data concerning driftwood is of value to researchers in fields as diverse as oceanography, geomorphology, and human occupation. Yet studies on the subject in the Canadian Arctic have only recently been carried out, and the present study is the first in Nunavik (northeastern Canada). This paper documents the composition, characteristics, and origin of modern driftwood pieces on the beaches of the eastern coast of Hudson Bay. A total of 1057 samples from Ivujivik, Akulivik, Inukjuak, and Umiujaq were identified as belonging to four coniferous species (Picea sp., Larix sp., Abies sp. likely balsamea, and Thuja sp. likely occidentalis) and four deciduous species (Salix sp., Populus sp., Alnus sp., and Betula sp., likely papyrifera). Spruce largely predominate; white birch, white cedar, and fir are rare. The presence of the latter species proves that some of the wood originated from south-southeast of James Bay. Driftwood found in the southern area (Umiujaq) are more numerous, larger, and less degraded than driftwood in the north (Ivujivik). However, many large coniferous samples were found as far north as Akulivik, indicating that they likely traveled a great distance, unlike the smaller wood specimens (especially deciduous samples). All of the wood that we analyzed died relatively young, with an average age of 63 years for conifers and 23 years for deciduous. Measurements of ring widths and the cross-dating of samples with existing reference chronologies of living trees along Hudson Bay and James Bay revealed several possible correlations and origins for wood found in same areas.
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