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https://www.readbyqxmd.com/read/28715138/microbial-functional-diversity-covaries-with-permafrost-thaw-induced-environmental-heterogeneity-in-tundra-soil
#1
Mengting M Yuan, Jin Zhang, Kai Xue, Liyou Wu, Ye Deng, Jie Deng, Lauren Hale, Xishu Zhou, Zhili He, Yunfeng Yang, Joy D Van Nostrand, Edward A G Schuur, Konstantinos T Konstantinidis, C Ryan Penton, James R Cole, James M Tiedje, Yiqi Luo, Jizhong Zhou
Permafrost soil in high latitude tundra is one of the largest terrestrial carbon (C) stocks and is highly sensitive to climate warming. Understanding microbial responses to warming induced environmental changes are critical to evaluating their influences on soil biogeochemical cycles. In this study, a functional gene array (i.e. GeoChip 4.2) was used to analyze the functional capacities of soil microbial communities collected from a naturally degrading permafrost region in Central Alaska. Varied thaw history was reported to be the main driver of soil and plant differences across a gradient of minimally, moderately and extensively thawed sites...
July 17, 2017: Global Change Biology
https://www.readbyqxmd.com/read/28703199/tundra-uptake-of-atmospheric-elemental-mercury-drives-arctic-mercury-pollution
#2
Daniel Obrist, Yannick Agnan, Martin Jiskra, Christine L Olson, Dominique P Colegrove, Jacques Hueber, Christopher W Moore, Jeroen E Sonke, Detlev Helmig
Anthropogenic activities have led to large-scale mercury (Hg) pollution in the Arctic. It has been suggested that sea-salt-induced chemical cycling of Hg (through 'atmospheric mercury depletion events', or AMDEs) and wet deposition via precipitation are sources of Hg to the Arctic in its oxidized form (Hg(ii)). However, there is little evidence for the occurrence of AMDEs outside of coastal regions, and their importance to net Hg deposition has been questioned. Furthermore, wet-deposition measurements in the Arctic showed some of the lowest levels of Hg deposition via precipitation worldwide, raising questions as to the sources of high Arctic Hg loading...
July 12, 2017: Nature
https://www.readbyqxmd.com/read/28702907/vascular-plants-as-ecological-indicators-of-metals-in-alpine-vegetation-karkonosze-sw-poland
#3
Bronisław Wojtuń, Aleksandra Samecka-Cymerman, Ludwik Żołnierz, Adam Rajsz, Alexander J Kempers
Calluna vulgaris, Carex rigida, Deschampsia flexuosa, Nardus stricta and Vaccinium myrtillus are abundant in the vegetation of mountainous areas in Northern and Central Europe. Knowledge of their ability to accumulate increased amounts of metals could be useful in the evaluation of environmental pollution in the alpine tundra of high mountains. Additionally, this investigation may contribute to understanding the rate and direction of recent vegetation change in Karkonosze and similar types of environments. Our investigation revealed that Carex rigida, C...
July 12, 2017: Environmental Science and Pollution Research International
https://www.readbyqxmd.com/read/28671536/paenibacillus-polysaccharolyticus-sp-nov-a-xylanolytic-and-cellulolytic-bacteria-isolated-from-leaves-of-bamboo-phyllostachys-aureosulcata
#4
Munusamy Madhaiyan, Selvaraj Poonguzhali, Venkatakrishnan Sivaraj Saravanan, Veeramuthu Duraipandiyan, Naif Abdullah Al-Dhabi, Soon-Wo Kwon, William B Whitman
A novel xylanolytic and cellulolytic strain, BL9T, was isolated from leaves of the Bamboo plants maintained at the Tamil Nadu Agricultural University Campus, Coimbatore, India. On the basis of the results of 16S rRNA gene analysis, it was determined to be phylogenetically close to the type strains of Paenibacillus amylolyticus NRRL NRS-290T (98.3 %), Paenibacillus barcinonensis BP-23T (98.1 %), Paenibacillus tundrae A10bT (98.0 %) and Paenibacillus xylanexedens B22aT (97.6 %). The strain stained Gram variable and was aerobic, motile and catalase- and oxidase-positive, with rod-shaped cells...
July 3, 2017: International Journal of Systematic and Evolutionary Microbiology
https://www.readbyqxmd.com/read/28653471/experimental-warming-alters-migratory-caribou-forage-quality
#5
Tara J Zamin, Steeve D Côté, Jean-Pierre Tremblay, Paul Grogan
Global declines in caribou and reindeer (Rangifer) populations have drawn attention to the myriad of stressors that these arctic and boreal forest herbivores currently face. Arctic warming has resulted in increased tundra shrub growth and therefore Rangifer forage quantity. However, its effects on forage quality have not yet been addressed although they may be critical to Rangifer body condition and fecundity. We investigated the impact of summer warming on the quality of forage available to the Bathurst caribou herd using experimental greenhouses (n=5) located in mesic birch hummock tundra in the central Canadian Low Arctic...
June 27, 2017: Ecological Applications: a Publication of the Ecological Society of America
https://www.readbyqxmd.com/read/28637304/effects-of-alternative-electron-acceptors-on-the-activity-and-community-structure-of-methane-producing-and-consuming-microbes-in-the-sediments-of-two-shallow-boreal-lakes
#6
Antti J Rissanen, Anu Karvinen, Hannu Nykänen, Sari Peura, Marja Tiirola, Anita Mäki, Paula Kankaala
The role of anaerobic CH4 oxidation in controlling lake sediment CH4 emissions remains unclear. Therefore, we tested how relevant EAs (SO42-, NO3-, Fe3+, Mn4+, O2) affect CH4 production and oxidation in the sediments of two shallow boreal lakes. The changes induced to microbial communities by the addition of Fe3+ and Mn4+ were studied using next-generation sequencing targeting the 16S rRNA and methyl-coenzyme M reductase (mcrA) genes and mcrA transcripts. Putative anaerobic CH4 oxidizing archaea (ANME-2D) and bacteria (NC 10) were scarce (up to 3...
June 15, 2017: FEMS Microbiology Ecology
https://www.readbyqxmd.com/read/28629109/biological-methanol-production-by-immobilized-methylocella-tundrae-using-simulated-biohythane-as-a-feed
#7
Sanjay K S Patel, Raushan K Singh, Ashok Kumar, Jae-Hoon Jeong, Seong Hun Jeong, Vipin C Kalia, In-Won Kim, Jung-Kul Lee
Biohythane may be used as an alternative feed for methanol production instead of costly pure methane. In this study, methanol production potential of Methylocella tundrae immobilized through covalent immobilization, adsorption, and encapsulation was evaluated. Cells covalently immobilized on groundnut shells and chitosan showed a relative methanol production potential of 83.9 and 91.6%, respectively, compared to that of free cells. The maximum methanol production by free cells and cells covalently immobilized on groundnut shells and chitosan was 6...
October 2017: Bioresource Technology
https://www.readbyqxmd.com/read/28620357/the-effectiveness-of-nitrate-mediated-control-of-the-oil-field-sulfur-cycle-depends-on-the-toluene-content-of-the-oil
#8
Navreet Suri, Johanna Voordouw, Gerrit Voordouw
The injection of nitrate is one of the most commonly used technologies to impact the sulfur cycle in subsurface oil fields. Nitrate injection enhances the activity of nitrate-reducing bacteria, which produce nitrite inhibiting sulfate-reducing bacteria (SRB). Subsequent reduction of nitrate to di-nitrogen (N2) alleviates the inhibition of SRB by nitrite. It has been shown for the Medicine Hat Glauconitic C (MHGC) field, that alkylbenzenes especially toluene are important electron donors for the reduction of nitrate to nitrite and N2...
2017: Frontiers in Microbiology
https://www.readbyqxmd.com/read/28591201/hippocampal-neurogenesis-and-volume-in-migrating-and-wintering-semipalmated-sandpipers-calidris-pusilla
#9
Nara Gyzely de Morais Magalhães, Cristovam Guerreiro Diniz, Daniel Guerreiro Diniz, Ediely Pereira Henrique, Patrick Douglas Corrêa Pereira, Isis Ananda Matos Moraes, Mauro André Damasceno de Melo, David Francis Sherry, Cristovam Wanderley Picanço Diniz
Long distance migratory birds find their way by sensing and integrating information from a large number of cues in their environment. These cues are essential to navigate over thousands of kilometers and reach the same breeding, stopover, and wintering sites every year. The semipalmated sandpiper (Calidris pusilla) is a long-distance migrant that breeds in the arctic tundra of Canada and Alaska and winters on the northeast coast of South America. Its fall migration includes a 5,300-kilometer nonstop flight over the Atlantic Ocean...
2017: PloS One
https://www.readbyqxmd.com/read/28566722/community-and-species-specific-responses-of-plant-traits-to-23-years-of-experimental-warming-across-subarctic-tundra-plant-communities
#10
Gaurav Baruah, Ulf Molau, Yang Bai, Juha M Alatalo
To improve understanding of how global warming may affect competitive interactions among plants, information on the responses of plant functional traits across species to long-term warming is needed. Here we report the effect of 23 years of experimental warming on plant traits across four different alpine subarctic plant communities: tussock tundra, Dryas heath, dry heath and wet meadow. Open-top chambers (OTCs) were used to passively warm the vegetation by 1.5-3 °C. Changes in leaf width, leaf length and plant height of 22 vascular plant species were measured...
May 31, 2017: Scientific Reports
https://www.readbyqxmd.com/read/28559886/global-diversity-of-desert-hypolithic-cyanobacteria
#11
Donnabella C Lacap-Bugler, Kevin K Lee, Stephen Archer, Len N Gillman, Maggie C Y Lau, Sebastian Leuzinger, Charles K Lee, Teruya Maki, Christopher P McKay, John K Perrott, Asunción de Los Rios-Murillo, Kimberley A Warren-Rhodes, David W Hopkins, Stephen B Pointing
Global patterns in diversity were estimated for cyanobacteria-dominated hypolithic communities that colonize ventral surfaces of quartz stones and are common in desert environments. A total of 64 hypolithic communities were recovered from deserts on every continent plus a tropical moisture sufficient location. Community diversity was estimated using a combined t-RFLP fingerprinting and high throughput sequencing approach. The t-RFLP analysis revealed desert communities were different from the single non-desert location...
2017: Frontiers in Microbiology
https://www.readbyqxmd.com/read/28559346/increased-nitrous-oxide-emissions-from-arctic-peatlands-after-permafrost-thaw
#12
Carolina Voigt, Maija E Marushchak, Richard E Lamprecht, Marcin Jackowicz-Korczyński, Amelie Lindgren, Mikhail Mastepanov, Lars Granlund, Torben R Christensen, Teemu Tahvanainen, Pertti J Martikainen, Christina Biasi
Permafrost in the Arctic is thawing, exposing large carbon and nitrogen stocks for decomposition. Gaseous carbon release from Arctic soils due to permafrost thawing is known to be substantial, but growing evidence suggests that Arctic soils may also be relevant sources of nitrous oxide (N2O). Here we show that N2O emissions from subarctic peatlands increase as the permafrost thaws. In our study, the highest postthaw emissions occurred from bare peat surfaces, a typical landform in permafrost peatlands, where permafrost thaw caused a fivefold increase in emissions (0...
June 13, 2017: Proceedings of the National Academy of Sciences of the United States of America
https://www.readbyqxmd.com/read/28558420/understanding-the-drivers-of-extensive-plant-damage-in-boreal-and-arctic-ecosystems-insights-from-field-surveys-in-the-aftermath-of-damage
#13
Jarle W Bjerke, Rachael Treharne, Dagrun Vikhamar-Schuler, Stein R Karlsen, Virve Ravolainen, Stef Bokhorst, Gareth K Phoenix, Zbigniew Bochenek, Hans Tømmervik
The exact cause of population dieback in nature is often challenging to identify retrospectively. Plant research in northern regions has in recent decades been largely focussed on the opposite trend, namely increasing populations and higher productivity. However, a recent unexpected decline in remotely-sensed estimates of terrestrial Arctic primary productivity suggests that warmer northern lands do not necessarily result in higher productivity. As large-scale plant dieback may become more frequent at high northern latitudes with increasing frequency of extreme events, understanding the drivers of plant dieback is especially urgent...
December 1, 2017: Science of the Total Environment
https://www.readbyqxmd.com/read/28515896/a-worldwide-phylogeography-of-the-whiteworm-lichens-thamnolia-reveals-three-lineages-with-distinct-habitats-and-evolutionary-histories
#14
Ioana Onuţ-Brännström, Leif Tibell, Hanna Johannesson
Thamnolia is a lichenized fungus with an extremely wide distribution, being encountered in arctic and alpine environments in most continents. In this study, we used molecular markers to investigate the population structure of the fungal symbiont and the associated photosynthetic partner of Thamnolia. By analyzing molecular, morphological, and chemical variation among 253 specimens covering the species distribution range, we revealed the existence of three mycobiont lineages. One lineage (Lineage A) is confined to the tundra region of Siberia and the Aleutian Islands, a second (Lineage B) is found in the high alpine region of the Alps and the Carpathians Mountains, and a third (Lineage C) has a worldwide distribution and covers both the aforementioned ecosystems...
May 2017: Ecology and Evolution
https://www.readbyqxmd.com/read/28508037/arctic-greening-from-warming-promotes-declines-in-caribou-populations
#15
Per Fauchald, Taejin Park, Hans Tømmervik, Ranga Myneni, Vera Helene Hausner
The migratory tundra caribou herds in North America follow decadal population cycles, and browsing from abundant caribou could be expected to counteract the current climate-driven expansion of shrubs in the circumpolar tundra biome. We demonstrate that the sea ice cover in the Arctic Ocean has provided a strong signal for climate-induced changes on the adjacent caribou summer ranges, outperforming other climate indices in explaining the caribou-plant dynamics. We found no evidence of a negative effect of caribou abundance on vegetation biomass...
April 2017: Science Advances
https://www.readbyqxmd.com/read/28488798/a-comparison-of-sedimentary-dna-and-pollen-from-lake-sediments-in-recording-vegetation-composition-at-the-siberian-treeline
#16
Bastian Niemeyer, Laura S Epp, Kathleen R Stoof-Leichsenring, Luidmila A Pestryakova, Ulrike Herzschuh
Reliable information on past and present vegetation is important to project future changes, especially for rapidly transitioning areas such as the boreal treeline. To study past vegetation, pollen analysis is common, while current vegetation is usually assessed by field surveys. Application of detailed sedimentary DNA (sedDNA) records has the potential to enhance our understanding of vegetation changes, but studies systematically investigating the power of this proxy are rare to date. This study compares sedDNA metabarcoding and pollen records from surface sediments of 31 lakes along a north-south gradient of increasing forest cover in northern Siberia (Taymyr peninsula) with data from field surveys in the surroundings of the lakes...
May 10, 2017: Molecular Ecology Resources
https://www.readbyqxmd.com/read/28488280/open-tundra-persist-but-arctic-features-decline-vegetation-changes-in-the-warming-fennoscandian-tundra
#17
Katariina E M Vuorinen, Lauri Oksanen, Tarja Oksanen, Anni Pyykönen, Johan Olofsson, Risto Virtanen
In the forest-tundra ecotone of the North Fennoscandian inland, summer and winter temperatures have increased by two to three centigrades since 1965, which is expected to result in major vegetation changes. To document the expected expansion of woodlands and scrublands and its impact on the arctic vegetation, we repeated a vegetation transect study conducted in 1976 in the Darju, spanning from woodland to a summit, 200 m above the tree line. Contrary to our expectations, tree line movement was not detected, and there was no increase in willows or shrubby mountain birches, either...
May 10, 2017: Global Change Biology
https://www.readbyqxmd.com/read/28484237/no-protection-of-permafrost-due-to-desertification-on-the-qinghai-tibet-plateau
#18
Qingbai Wu, Wenbing Yu, Huijun Jin
Desertification of tundra regions may form an escalating cycle with permafrost degradation where more permafrost thaw leads to continued desertification. This traditional viewpoint has been challenged in recent reports that state desertification protects the underlying permafrost. However, our measurements of soil temperature from nine sites in the Honglianghe River Basin, interior Qinghai-Tibet Plateau, show that desertification can degrade permafrost. If one compares the permafrost temperatures at sites with thin sand covers (e...
May 8, 2017: Scientific Reports
https://www.readbyqxmd.com/read/28484001/carbon-dioxide-sources-from-alaska-driven-by-increasing-early-winter-respiration-from-arctic-tundra
#19
Róisín Commane, Jakob Lindaas, Joshua Benmergui, Kristina A Luus, Rachel Y-W Chang, Bruce C Daube, Eugénie S Euskirchen, John M Henderson, Anna Karion, John B Miller, Scot M Miller, Nicholas C Parazoo, James T Randerson, Colm Sweeney, Pieter Tans, Kirk Thoning, Sander Veraverbeke, Charles E Miller, Steven C Wofsy
High-latitude ecosystems have the capacity to release large amounts of carbon dioxide (CO2) to the atmosphere in response to increasing temperatures, representing a potentially significant positive feedback within the climate system. Here, we combine aircraft and tower observations of atmospheric CO2 with remote sensing data and meteorological products to derive temporally and spatially resolved year-round CO2 fluxes across Alaska during 2012-2014. We find that tundra ecosystems were a net source of CO2 to the atmosphere annually, with especially high rates of respiration during early winter (October through December)...
May 23, 2017: Proceedings of the National Academy of Sciences of the United States of America
https://www.readbyqxmd.com/read/28476175/biochemical-and-proteomics-analyses-of-antioxidant-enzymes-reveal-the-potential-stress-tolerance-in-rhododendron-chrysanthum-pall
#20
Xiaofu Zhou, Silin Chen, Hui Wu, Yi Yang, Hongwei Xu
BACKGROUND: Rhododendron chrysanthum Pall., an endangered species with significant ornamental and medicinal value, is endemic to the Changbai Mountain of China and can also serve as a significant plant resource for investigating the stress tolerance in plants. Proteomics is an effective analytical tool that provides significant information about plant metabolism and gene expression. However, no proteomics data have been reported for R. chrysanthum previously. In alpine tundra, the abiotic stress will lead to a severe over-accumulation of reactive oxygen species (ROS)...
May 3, 2017: Biology Direct
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