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Carbon dioxide fluxes of tundra vegetation communities on an esker top in the low-Arctic
Get PDFPrevious studies have shown that carbon dioxide fluxes vary considerably among Arctic environments and it is important to assess these differences in order to develop our understanding of the role of Arctic tundra in the global carbon cycle. Although many previous studies have examined tundra carbon dioxide fluxes, few have concentrated on elevated terrain (hills and ridge tops) that is exposed to harsh environmental conditions resulting in sparse vegetation cover and seemingly low productivity. In this study we measured carbon dioxide (CO2) exchange of four common tundra communities on the crest of an esker located in the central Canadian low-Arctic. The objectives were to quantify and compare CO2 fluxes from these communities, investigate responses to environmental variables and qualitatively compare fluxes with those from similar communities growing in less harsh lowland tundra environments. Measurements made during July and August 2010 show there was little difference in net ecosystem exchange (NEE) and gross ecosystem production (GEP) among the three deciduous shrub communities, Arctous alpina, Betula glandulosa and Vaccinium uliginosum, with means ranging from −4.09 to −6.57 μmol·m−2·s−1 and −7.92 to −9.24 μmol·m−2·s−1, respectively. Empetrum nigrum communities had significantly smaller mean NEE and GEP (−1.74 and −4.08 μmol·m−2·s−1, respectively). Ecosystem respiration (ER) was similar for all communities (2.56 to 3.03 μmol·m−2·s−1), except the B. glandulosa community which had a larger mean flux (4.66 μmol·m−2·s−1). Overall, fluxes for these esker-top communities were near the upper range of fluxes reported for other tundra communities. ER was related to soil temperature in all of the communities. Only B. glandulosa GEP and ER showed sensitivity to a persistent decline in soil moisture throughout the study. These findings may have important implications for how esker tops would be treated in construction of regional carbon budgets and for predicting the impacts of climate change on Arctic tundra future carbon budgets
Effects of sunlight on tundra nitrous oxide and methane fluxes in maritime Antarctica
Get PDFThe relationships of nitrous oxide (N2O) and methane (CH4) emissions to other environmental parameters have been studied extensively in Antarctic terrestrial ecosystems. However, the effects of sunlight on soil N2O and CH4 fluxes are neglected across the Antarctic tundra. Here, fluxes of N2O and CH4 from maritime Antarctic tundra soils were measured in the absence and presence of sunlight during three summers. The N2O fluxes averaged −4.6±1.2 μg·m−2·h−1 in the absence of sunlight and 5.7±1.5 μg·m−2·h−1 in its presence; CH4 fluxes averaged 119.8±24.5 μg·m−2·h−1 (absence) and −40.5±28.3 μg·m−2·h−1 (presence). The correlations between N2O and CH4 fluxes and other environmental variables (e.g., soil moisture, temperature, organic and inorganic material) were not statistically significant (P>0.05) at all sites. On average, sunlight significantly increased N2O emissions and CH4 uptake by 10.3 μg·m−2·h−1 and 160.3 μg·m−2·h−1, respectively. This study indicates that sunlight is critical for accurately estimating N2O and CH4 budgets from maritime Antarctica and necessary for constraining the role of their emissions from tundra soil
Structure and function of a novel cold regulated cold shock domain containing protein from an obligate psychrophilic yeast, Glaciozyma antarctica
Get PDFCold shock domain (CSD)-containing proteins are one of the groups of the evolutionarily conserved nucleic acid-binding proteins in all three domains of life consisting of an ancient beta-barrel fold that serves to bind nucleic acids. The cDNA of a novel protein-coding gene containing CSD was cloned from Glaciozyma antarctica designated as Ga16676. The full length of Ga16676 gene with the size of 1335 bp encodes for an N-terminal CSD with conserved nucleic acids binding motif RNP1 and RNP2. The Ga16676 gene was cloned in pET30 Ek/LIC, sequenced, expressed and its resistance towards cold was characterized. Recombinant protein expression of Ga16676 showed overexpressed soluble expression in both supernatant and pellet forms at 20 ℃. The effects of recombinant CSD protein overexpression on colony formation shows that E. coli cells were able to grow at 37 ℃ and 20 ℃ but not at 4 ℃ while E. coli_Ga16676 cells were able to grow at all temperatures tested. In addition, E. coli_Ga16676 cells showed higher growth rate compared to empty E. coli cells at 10 ℃. Structural analysis of Ga16676 reveals some interesting findings such as more aromatic interactions for efficient binding in low energy environment, a longer loop that may contribute to structural flexibility and clustering of charged amino acids on the protein surface that is important for protein stability and flexibility
Evaluation of the Polar Code in different environments and for different maritime activities in the two polar regions
Get PDFBecause of the decrease in sea ice coverage, maritime activities in the polar regions have increased steadily over the years and several issues related to maritime activities have arisen. It is essential to understand these challenges because they could have serious political, environmental, and economic consequences. Although there are significant geographical and legal differences and differences in the types of activities between the Arctic and the Antarctic, a single International Maritime Organization Polar Code covers both regions. In this analysis, changes in polar regions are introduced, and the differences between the Arctic and Antarctic are discussed. The differences in maritime activities in the two polar regions are then discussed, and the Polar Code is evaluated in terms of these differences
Outcomes of the webinar: Potential of O&G projects in the Far East in new economic realities
Get PDFAs a preamble to the 5th Annual International East Russia Oil and Gas Forum, which is scheduled to take place in Vladivostok on 7-8 July 2021, British consultancy Vostock Capital hosted a free webinar “Potential of O&G projects in the Far East in new economic realities”
Post-pandemic Prospects of O&G Projects
Get PDFA presentation that was held on the webinar: Potential of O&G Projects of the Far East in New Economic Realities in May 2020 by Vostock Capita
Effects of elevated temperatures on growth and photosynthetic performance of polar Chlorella
Get PDFGlobal warming has been the subject of concern in today’s world with elevating temperature causing the melting of polar ice and increasing sea level. The aim of this study was to investigate the physiological and photosynthetic performance of two polar Chlorella, namely Chlorella UMACC 250 and Chlorella UMACC 234 to elevating temperatures as might be experienced under future warming scenarios. The cultures were exposed to three different temperatures of 4 ℃, 8 ℃ and 12 ℃. The growth and photosynthetic activity were determined every 2 d for a period of 10 d. At the end of the experiment, the cultures were harvested and analysed for biochemical composition. Both Chlorella strains were able to tolerate higher temperatures than their ambient temperature. The final pigments content showed an increasing trend with increased temperatures for both strains. The photosynthetic activities were measured using pulse-amplitude modulation (PAM) fluorometer. The photosynthetic parameters including maximum quantum efficiency (Fv/Fm), maximum relative electron transport rate (rETRmax), light harvesting efficiency () and photoadaptive index (Ek) were derived from the rapid light curves (RLCs). Both Chlorella strains showed a slight decline in growth and photosynthetic activities at the initial part of the experiment. However, they showed the ability to recuperate with Chlorella UMACC 250 recovers better compared to Chlorella UMACC 234. Both Chlorella strains showed similar trend in their carbohydrate content at 12 ℃, while the protein content of Chlorella UMACC 234 decreased when exposed to increasing temperatures. The results indicated that polar Chlorella are able to survive at increased temperatures throughout the experiment
Sino-Russian cooperation on the sustainable utilization of Arctic biological resources: modernizing traditional knowledge
Get PDFConsidering the effects of global warming, humans need to face the possibility of an ice-free Arctic during summer. Russia spans Eurasia and occupies more Arctic lands than any other country. This vast area has a great variety of species, and the geography and environment of the Arctic have endowed these species with unique and valuable properties. All the world’s ancient nations have their traditional knowledge. The indigenous traditional knowledge of the Arctic and the knowledge embedded in traditional Chinese medicine are part of the world’s time-honored wisdom. Some of this ancient lore cannot be verified by modern scientific methods, but the methods are effective in practice, triggering further exploration and innovation. Russian Arctic indigenous people have a long history of using the Arctic biological resources. The use of therapeutic materials in traditional Chinese medicine has many similarities with the use of Arctic biological resources by indigenous peoples. Both types of traditional knowledge can inspire new approaches to the development of the Arctic biological resources. China and Russia are among the world’s largest countries, and it is important that they cooperate in developing the Arctic biological resources. The development of sustainable use of these resources, while updating traditional knowledge, is an urgently needed investment that requires an innovative approach
Tropical–Antarctic connections of an explosive cyclone in southern Brazil: rainfall stable isotope ratios and atmospheric analysis
Get PDFThis study analyzes the stable isotopic ratio (δ18O) and the synoptic characteristics of a precipitation event that occurred in the southernmost state of Brazil, Rio Grande do Sul, a region sensitive to explosive cyclogenesis in years with enhanced tropic-pole interactions. The main objective was to evaluate the influence of tropical and Antarctic climate systems on the event. Cavity ring-down spectroscopy was used for the water isotopic analysis, and NCEP CFSv2 data were employed for the synoptic analysis of rainfall over a 48-h period. An Amazonian isotopic signature on precipitated water was identified. A strong, low-level meridional flow from the Amazon Basin, combined with the development of a frontal system, resulted in intense cyclogenesis that generated an explosive cyclone