@article {4839, title = {Impact of meltwater flow intensity on the spatiotemporal heterogeneity of microbial mats in the McMurdo Dry Valleys, Antarctica}, journal = {ISME Communications}, volume = {3}, year = {2023}, month = {01/2023}, pages = {3}, abstract = {

The meltwater streams of the McMurdo Dry Valleys are hot spots of biological diversity in the climate-sensitive polar desert landscape. Microbial mats, largely comprised of cyanobacteria, dominate the streams which flow for a brief window of time (~10 weeks) over the austral summer. These communities, critical to nutrient and carbon cycling, display previously uncharacterized patterns of rapid destabilization and recovery upon exposure to variable and physiologically detrimental conditions. Here, we characterize changes in biodiversity, transcriptional responses and activity of microbial mats in response to hydrological disturbance over spatiotemporal gradients. While diverse metabolic strategies persist between marginal mats and main channel mats, data collected from 4 time points during the austral summer revealed a homogenization of the mat communities during the mid-season peak meltwater flow, directly influencing the biogeochemical roles of this stream ecosystem. Gene expression pattern analyses identified strong functional sensitivities of nitrogen-fixing marginal mats to changes in hydrological activities. Stress response markers detailed the environmental challenges of each microhabitat and the molecular mechanisms underpinning survival in a polar desert ecosystem at the forefront of climate change. At mid and end points in the flow cycle, mobile genetic elements were upregulated across all mat types indicating high degrees of genome evolvability and transcriptional synchronies. Additionally, we identified novel antifreeze activity in the stream microbial mats indicating the presence of ice-binding proteins (IBPs). Cumulatively, these data provide a new view of active intra-stream diversity, biotic interactions and alterations in ecosystem function over a high-flow hydrological regime.

}, keywords = {LTER-MCM}, doi = {10.1038/s43705-022-00202-8}, url = {https://www.nature.com/articles/s43705-022-00202-8}, author = {Zoumplis, Angela and Kolody, Bethany C. and Kaul, Drishti and Zheng, Hong and Venepally, Pratap and Diane M. McKnight and Cristina D. Takacs-Vesbach and DeVries, Arthur L. and Allen, Andrew E.} } @article {4335, title = {Sabbea gen. nov., a new diatom genus (Bacillariophyta) from continental Antarctica}, journal = {Phytotaxa}, volume = {418}, year = {2019}, month = {09/2019}, abstract = {

The non-marine diatom flora of the Antarctic Continent includes several endemic taxa recorded over the past 100 years. One of these taxa, Navicula adminensis D.Roberts \& McMinn, was described from the Vestfold Hills, East Antarctica. Detailed light and scanning electron microscopy observations have shown that based on its morphological features, the species does not belong to the genus Navicula sensu stricto. To determine the most closely related genera to N. adminensis, the morpho- logical features of Adlafia, Kobayasiella, Envekadea, Stenoneis, Berkeleya, Climaconeis, and Parlibellus were compared with those of N. adminensis. Although each of these genera shows one or more similar features, none of them accommodates the salient morphological characteristics of N. adminensis. Therefore, a new genus, Sabbea gen. nov., is herein described, and Navicula adminensis is formally transferred to the new genus as Sabbea adminensis comb. nov. The genus Sabbea is characterized by uniseriate striae composed of small, rounded areolae occluded externally by individual hymenes, a rather simple raphe structure with straight, short proximal ends and short terminal raphe fissures, open girdle bands with double perforation and a very shallow mantle.

}, keywords = {LTER-MCM, Bacillariophyta, Cape Royds, East Antarctica, McMurdo Dry Valleys, new genus, Vestfold Hills}, doi = {10.11646/phytotaxa.418.1.2}, url = {https://www.mapress.com/j/pt/article/view/phytotaxa.418.1.2}, author = {Bishop, Jordan and Kopalov{\'a}, Kate{\v r}ina and Darling, Joshua P. and Schulte, Nicholas O. and Tyler J. Kohler and McMinn, Andrew and Sarah A. Spaulding and Diane M. McKnight and Bart Van de Vijver} } @article {1087, title = {The influence of stream thermal regimes and preferential flow paths on hyporheic exchange in a glacial meltwater stream}, journal = {Water Resources Research}, volume = {49}, year = {2013}, month = {09/2013}, pages = {5552 - 5569}, keywords = {LTER-MCM}, doi = {10.1002/wrcr.20410}, url = {http://onlinelibrary.wiley.com/doi/10.1002/wrcr.20410/pdf}, author = {Cozzetto, K and Kenneth E. Bencala and Michael N. Gooseff and Diane M. McKnight} } @article {1216, title = {Inland diatoms from the McMurdo Dry Valleys and James Ross Island, Antarctica}, journal = {Botany-Botanique}, volume = {12}, year = {2008}, pages = {1378-1392}, keywords = {LTER-MCM}, doi = {LTER}, author = {Rhea M.M. Esposito and Sarah A. Spaulding and Diane M. McKnight and De Vijver, B and Kopalova, K and Lubinski, D and Brenda L. Hall and Whittaker, T} } @article {1335, title = {Inorganic nitrogen and phosphorus dynamics of Antarctic glacial meltwater streams as controlled by hyporheic exchange and benthic autotrophic communities}, journal = {Journal of the North American Benthological Society}, volume = {23}, year = {2004}, pages = {171-188}, keywords = {LTER-MCM}, author = {Diane M. McKnight and Robert L. Runkel and John H. Duff and Cathy M. Tate and Daryl L. Moorhead} } @mastersthesis {1391, title = {Interannual variation in phytoplankton dynamics in Lake Fryxell}, volume = {M.S.}, year = {2002}, school = {University of Colorado}, type = {masters}, keywords = {LTER-MCM}, doi = {LTER}, author = {Van Matre, E} } @mastersthesis {1417, title = {The influence of mixotroph growth on DOM chemistry in Pony Lake, a eutrophic coastal pond in Antarctica}, volume = {M.S.}, year = {2001}, school = {University of Colorado}, type = {masters}, keywords = {LTER-MCM}, doi = {LTER}, author = {Brown, A} } @article {1587, title = {The influence of stream channel characteristics on streamflow and annual water budgets for lakes in Taylor Valley}, journal = {Antarctic Journal of the U.S.}, volume = {30}, year = {1995}, pages = {284-287}, keywords = {LTER-MCM}, author = {Harold R. House and Diane M. McKnight and Paul Von Guerard} }