Microbial carbon use and associated changes in microbial community structure in high-Arctic tundra soils under elevated temperature

In the high-Arctic, increased temperature results in permafrost thawing and increased primary production. This fresh plant-derived material is predicted to prime microbial consortia for degradation of the organic matter stored in tundra soils. However, the effects of warming and plant input on the microbial community structure is hardly known. We assessed the use of glycine, a readily available C and N source, and cellulose, a long C-biopolymer, by prokaryotic and fungal communities using DNA-SIP in tundra soils incubated at 8 °C or 16 °C. Glycine addition contributed mainly to instantaneous microbial carbon use and priming of soil organic matter decomposition, particularly under elevated temperature. By contrast, cellulose was linked to the dominant and active microbial communities, with potential carbon stabilization in soils. Our findings stress the importance of the type of plant-derived material in relation to microbial metabolism in high-Arctic soils and their consequences for the carbon cycle in response to global warming

What is APECS Belgium?

The Association of Polar Early Career Scientists (APECS) is an international and interdisciplinary organization for undergraduate and graduate students, postdoctoral researchers, early faculty members, educators and other people with interests in Polar Regions and the wider cryosphere. Its main goals are communication, education, outreach, and assistance to early career scientists. The APECS leadership team is comprised of early career researchers that are interested in and committed to furthering the activities and the future directions of the organisation. Project initiation and management, web-based or in-person events, are carried out by a number of member-initiated working groups and committees made up of both members and mentors. APECS Belgium, the Belgian National Committee of APECS, was founded in 2011 and has organized and participated in many events and activities since; for example: Conference Symposia, Science fair, school visits, workshops, documentary screenings, outreach events and much more. APECS Belgium encourages polar research at the national level by promoting research projects and institutes in the Belgian territory and sharing the fascination of the Poles with other researchers and the community. Every early career scientist based in Belgium with an interest in the Polar Regions is highly encouraged to join us! We also invite people with links to polar education and research to become part of APECS Belgium. For more information, visit our website: www.apecsbelgium.wordpress.com

Comparative vegetation survey with focus on cryptogamic covers in the high Arctic along two differing catenas

Although cryptogamic covers are important ecosystem engineers in high Arctic tundra, they were often neglected in vegetation surveys. Hence we conducted a systematic survey of cryptogamic cover and vascular plant coverage and composition at two representative, but differing Arctic sites (Ny-angstrom lesund, Svalbard) along catenas with a natural soil moisture gradient, and integrated these data with physical-chemical soil properties. Soil samples were taken for comprehensive pedological and mineralogical analyses. Vegetation surveys were conducted based on classification by functional groups. Vascular plants were identified to species level. Correlation and multivariate statistical analysis were applied to determine the key environmental factors explaining vegetation patterns along the soil moisture gradients. We observed significant differences in gravimetric water, soil organic matter and nutrient contents along the moisture gradients. These differences were coincident with a shift in vegetation cover and species composition. While chloro- and cyanolichens were abundant at the drier sites, mosses dominated the wetter and vascular plants the intermediate plots. Twenty four vascular plant species could be identified, of which only six were present at both sites. Cryptogamic covers generally dominated with maximum areal coverage up to 70% and hence should be considered as a new additional syntaxon in future ground-truth and remote sensing based vegetation surveys of Svalbard. Multivariate analysis revealed that soil moisture showed the strongest relation between vegetation patterns, together with NH4-N and pH. In conclusion, soil moisture is a key driver in controlling cryptogamic cover and vegetation coverage and vascular plant species composition in high Arctic tundra