02236nas a2200241   4500008004100000245006500041210006400106260001200170300000900182490000700191520155500198653001501753653002401768653001801792653002601810653001201836653002201848100002501870700001701895700001501912700002101927856004601948       2022                        eng d00aGlacial legacies: Microbial communities of Antarctic refugia0 aGlacial legacies Microbial communities of Antarctic refugia  c10/2022  a14400 v113 a<p>In the cold deserts of the McMurdo Dry Valleys (MDV) the suitability of soil for microbial life is determined by both contemporary processes and legacy effects. Climatic changes and accompanying glacial activity have caused local extinctions and lasting geochemical changes to parts of these soil ecosystems over several million years, while areas of refugia may have escaped these disturbances and existed under relatively stable conditions. This study describes the impact of historical glacial and lacustrine disturbance events on microbial communities across the MDV to investigate how this divergent disturbance history influenced the structuring of microbial communities across this otherwise very stable ecosystem. Soil bacterial communities from 17 sites representing either putative refugia or sites disturbed during the Last Glacial Maximum (LGM) (22&ndash;17 kya) were characterized using 16 S metabarcoding. Regardless of geographic distance, several putative refugia sites at elevations above 600 m displayed highly similar microbial communities. At a regional scale, community composition was found to be influenced by elevation and geographic proximity more so than soil geochemical properties. These results suggest that despite the extreme conditions, diverse microbial communities exist in these putative refugia that have presumably remained undisturbed at least through the LGM. We suggest that similarities in microbial communities can be interpreted as evidence for historical climate legacies on an ecosystem-wide scale.</p>10aAntarctica10aMcMurdo Dry Valleys10ametabarcoding10amicrobial communities10arefugia10asoil biodiversity1 aJackson, Abigail, C.1 aJorna, Jesse1 aChaston, J1 aAdams, Byron, J.  uhttps://www.mdpi.com/2079-7737/11/10/144001902nas a2200181   4500008004100000245011100041210006900152260003900221490000900260520124000269653001901509653002401528653002601552653001801578100002601596700002901622856006901651       2020                        eng d00aResponse of microbial communities to climatic disturbances in Lake Bonney, McMurdo Dry Valleys, Antarctica0 aResponse of microbial communities to climatic disturbances in La  aOxford, OHbMiami Universityc20200 vM.S.3 a<p>The McMurdo Dry Valleys is a polar desert ecosystem which composes the largest ice-free area in Antarctica, with the exception of perennially ice-covered lakes and ponds. The lakes in the valleys are the only landscape unit that support metabolic activity year-round. Recent increases in air temperature and solar radiation have led to a chain of disturbances altering the environmental conditions of these lakes. In this study, we test the impact of climatic disturbances on microbial communities in Lake Bonney, one of the lakes in the MDV. Through an integrated approach of combining field studies on natural communities in the lake (in situ) and laboratory experiments on algal isolates (ex situ), this study will attempt to understand how phytoplankton, eukaryal and bacterial communities respond to simulated disturbances. Results from the in situ experiments showed that the moat is a unique and stressful environment for under-ice communities and that under-ice shallow communities are highly sensitive to climatic disturbances. The ex situ experiments showed that certain phytoplankton species, like the chlorophytes, are more resistant to environmental alterations and thus will outcompete other phytoplankton species.</p>10aclimate change10aMcMurdo Dry Valleys10amicrobial communities10aphytoplankton1 aSherwell, Shasten, S.1 aMorgan-Kiss, Rachael, M.  uhttp://rave.ohiolink.edu/etdc/view?acc_num=miami1595958688364877