02771nas a2200325   4500008004100000022001400041245013500055210006900190260001200259300001000271490000700281520179400288653001302082653001302095653001002108653001302118653002002131653001702151653001702168653003102185100002602216700001902242700002002261700002102281700001802302700002202320700002102342700002402363856005802387       2022                        eng d  a0022-364600aBlowin’ in the wind: Dispersal, structure, and metacommunity dynamics of aeolian diatoms in the McMurdo Sound region, Antarctica0 aBlowin in the wind Dispersal structure and metacommunity dynamic  c02/2022  a36-540 v583 a<p>Diatom metacommunities are structured by environmental, historical, and spatial factors that are often attributed to organism dispersal. In the McMurdo Sound region (MSR) of Antarctica, wind connects aquatic habitats through delivery of inorganic and organic matter. We evaluated the dispersal of diatoms in aeolian material and its relation to the regional diatom metacommunity using light microscopy and 18S rRNA high-throughput sequencing. The concentration of diatoms ranged from 0 to 8.76 * 10<sup>6</sup> valves &middot; g<sup>-1</sup> dry aeolian material. Up to 15% of whole cells contained visible protoplasm, indicating that up to 3.43 * 10<sup>4</sup> potentially viable individuals could be dispersed in a year to a single 2 cm<sup>2</sup>&nbsp;site. Diatom DNA and RNA was detected at each site, reinforcing the likelihood that we observed dispersal of viable diatoms. Of the 50 known morphospecies in the MSR, 72% were identified from aeolian material using microscopy. Aeolian community composition varied primarily by site. Meanwhile, each aeolian community was comprised of morphospecies found in aquatic communities from the same lake basin. These results suggest that aeolian diatom dispersal in the MSR is spatially structured, is predominantly local, and connects local aquatic habitats via a shared species pool. Nonetheless, aeolian community structure was distinct from that of aquatic communities, indicating that intrahabitat dispersal and environmental filtering also underlie diatom metacommunity dynamics. The present study confirms that a large number of diatoms are passively dispersed by wind across a landscape characterized by aeolian processes, integrating the regional flora and contributing to metacommunity structure and landscape connectivity.</p>10a18S rRNA10aairborne10aalgae10aassembly10aBacillariophyta10abiogeography10aconnectivity10ahigh-throughput sequencing1 aSchulte, Nicholas, O.1 aKhan, Alia, L.1 aSmith, Emma, W.1 aZoumplis, Angela1 aKaul, Drishti1 aAllen, Andrew, E.1 aAdams, Byron, J.1 aMcKnight, Diane, M.  uhttps://onlinelibrary.wiley.com/doi/10.1111/jpy.1322302399nas a2200217   4500008004100000245008500041210006900126260005400195490000700249520171000256653001501966653001701981653002401998653001402022653002402036653001002060653002402070100002502094700002102119856004102140       2022                        eng d00aEffect of climate history on the genetic structure of an Antarctic soil nematode0 aEffect of climate history on the genetic structure of an Antarct  aProvo, UT, USAbBrigham Young Universityc12/20220 vMS3 a<p>Historical climate disturbances such as glacial cycling and fluctuating stream, lake, and sea levels strongly influence the distribution and evolutionary trajectories of Antarctic terrestrial species. Antarctic invertebrates, with limited long-range mobility, including the ubiquitous sentinel nematode species <i>Scottnema lindsayae</i>, are especially sensitive to climate disturbances. We tested hypotheses associated with the historical geographic and population genetic structure of this species as it occurs across the McMurdo Dry Valleys (MDVs) of Antarctica. In order to reconstruct the influence of climate disturbance and ecological conditions on this species, partial mitochondrial COI gene sequences were sequenced and analyzed from individual <i>S. lindsayae</i> collected from sites across the MDVs reflecting a opposing gradients of climate disturbance during the Last Glacial Maximum (LGM). We found that populations were strongly geomorphic barriers with distinct haplotypes associated with valleys except among valleys that experienced glacial advance and retreat during the LGM. One monophyletic clade corresponds with valley systems that were undisturbed during the LGM indicating putative refugia areas. A second monophyletic clade corresponds to recent dispersal and expansion of evolutionarily younger populations into valleys that were strongly reworked by glacial activity during the LGM. Our work shows that contemporary populations of these animals are strongly structured by prior climate history. Such findings can be useful for interpreting long-term monitoring of demographic shifts of soil organisms in response to changing climate trends in the McMurdo Dry Valleys.</p>10aAntarctica10abiogeography10aclimate disturbance10aevolution10aMcMurdo Dry Valleys10apolar10apopulation genetics1 aJackson, Abigail, C.1 aAdams, Byron, J.  uhttp://hdl.lib.byu.edu/1877/etd12622