@article {4713, title = {Blowin{\textquoteright} in the wind: Dispersal, structure, and metacommunity dynamics of aeolian diatoms in the McMurdo Sound region, Antarctica}, journal = {Journal of Phycology}, volume = {58}, year = {2022}, month = {02/2022}, pages = {36-54}, abstract = {

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 * 106 valves \· g-1 dry aeolian material. Up to 15\% of whole cells contained visible protoplasm, indicating that up to 3.43 * 104 potentially viable individuals could be dispersed in a year to a single 2 cm2\ 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.

}, keywords = {LTER-MCM, 18S rRNA, airborne, algae, assembly, Bacillariophyta, biogeography, connectivity, high-throughput sequencing}, issn = {0022-3646}, doi = {10.1111/jpy.13223}, url = {https://onlinelibrary.wiley.com/doi/10.1111/jpy.13223}, author = {Schulte, Nicholas O. and Khan, Alia L. and Smith, Emma W. and Zoumplis, Angela and Kaul, Drishti and Allen, Andrew E. and Adams, Byron J. and Diane M. McKnight} } @thesis {4835, title = {Effect of climate history on the genetic structure of an Antarctic soil nematode}, volume = {MS}, year = {2022}, month = {12/2022}, school = {Brigham Young University}, type = {Master{\textquoteright}s thesis}, address = {Provo, UT, USA}, abstract = {

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 Scottnema lindsayae, 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 S. lindsayae 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.

}, keywords = {LTER-MCM, Antarctica, biogeography, climate disturbance, evolution, McMurdo Dry Valleys, polar, population genetics}, url = {http://hdl.lib.byu.edu/1877/etd12622}, author = {Jackson, Abigail C.}, editor = {Adams, Byron J.} }