@article {4996,
	title = {Drifting along: Using diatoms to track the contribution of microbial mats to particulate organic matter transport in a glacial meltwater stream in the McMurdo Dry Valleys, Antarctica},
	journal = {Frontiers in Microbiology},
	volume = {15},
	year = {2024},
	month = {05/2024},
	abstract = {<p>Flow pulses mobilize particulate organic matter (POM) in streams from the surrounding landscape and streambed. This POM serves as a source of energy and nutrients, as well as a means for organismal dispersal, to downstream communities. In the barren terrestrial landscape of the McMurdo Dry Valleys (MDV) of Antarctica, benthic microbial mats occupying different in-stream habitat types are the dominant POM source in the many glacier-fed streams. Many of these streams experience daily flow peaks that mobilize POM, and diatoms recovered from underlying stream sediments suggest that mat-derived diatoms in the POM are retained there through hyporheic exchange. Yet, \&lsquo;how much\&rsquo; and \&lsquo;when\&rsquo; different in-stream habitat types contribute to POM diatom assemblages is unknown. To quantify the contribution of different in-stream habitat types to POM diatom assemblages, we collected time-integrated POM samples over four diel experiments, which spanned a gradient of flow conditions over three summers. Diatoms from POM samples were identified, quantified, and compared with dominant habitat types (i.e., benthic \&lsquo;orange\&rsquo; mats, marginal \&lsquo;black\&rsquo; mats, and bare sediments). Like bulk POM, diatom cell concentrations followed a clockwise hysteresis pattern with stream discharge over the daily flow cycles, indicating supply limitation. Diatom community analyses showed that different habitat types harbor distinct diatom communities, and mixing models revealed that a substantial proportion of POM diatoms originated from bare sediments during baseflow conditions. Meanwhile, orange and black mats contribute diatoms to POM primarily during daily flow peaks when both cell concentrations and discharge are highest, making mats the most important contributors to POM diatom assemblages at high flows. These observations may help explain the presence of mat-derived diatoms in hyporheic sediments. Our results thus indicate a varying importance of different in-stream habitats to POM generation and export on daily to seasonal timescales, with implications for biogeochemical cycling and the local diatom metacommunity.</p>},
	keywords = {LTER-MCM, cyanobacteria, diatom, flow regime, hydrology, microbial mat, Nostoc},
	doi = {10.3389/fmicb.2024.1352666},
	url = {https://www.frontiersin.org/journals/microbiology/articles/10.3389/fmicb.2024.1352666/full},
	author = {Lee F. Stanish and Tyler J. Kohler and Darling, Joshua P. and Diane M. McKnight}
}
@article {1067,
	title = {Diel flow pulses drive particulate organic matter transport from microbial mats in a glacial meltwater stream in the McMurdo Dry Valleys},
	journal = {Water Resources Research},
	volume = {50},
	year = {2014},
	month = {01/2014},
	pages = {86-97},
	chapter = {86},
	abstract = { Many glacial meltwater streams in the McMurdo Dry Valleys (MDV) of Antarctica contain abundant microbial mats, representing hot spots of primary production in a barren landscape. These mats persist through the winter in a freeze-dried state and grow in the summer, experiencing a dynamic hydrologic regime as streamflow varies on a diel cycle and with weather conditions. During diel peaks in flow these streams transport particulate organic matter (POM) to the downstream closed-basin lakes. We investigated the spatial and temporal dynamics of POM transport derived from the scouring of microbial mats in Von Guerard Stream of the MDV. The results show clockwise hysteresis effects in POM concentration over diel flood pulses and suggests that POM transport in the MDVs is supply limited. Further studies are required to confirm this and to identify the potential contributing sources of POM. The hysteresis effect was modeled using an approach derived from models of sediment transport in streams. Spatial variations in POM transport indicate that patch-scale variations in bed shear stress and benthic biomass also influence transport which is integrated downstream over several 100{\textquoteright}s of meters. Large variations in the POM transport dynamics between different diel flood pulses were found to be related to the time since a resetting flood event and the regrowth of potentially mobile benthic biomass, providing further evidence of the importance of supply limitation and flow variability in controlling the organic matter flux of stream ecosystems.},
	keywords = {LTER-MCM},
	doi = {10.1002/2013WR014061},
	author = {Cullis, James D.S. and Lee F. Stanish and Diane M. McKnight}
}
@inbook {1170,
	title = {Diatoms as indicators of environmental change in Antarctic and subantarctic freshwaters},
	booktitle = {The Diatoms Applications for the Environmental and Earth Sciences},
	year = {2010},
	publisher = {Cambridge University Press},
	organization = {Cambridge University Press},
	edition = {2},
	keywords = {LTER-MCM},
	isbn = {9780521509961},
	url = {http://www.cambridge.org/us/academic/subjects/life-sciences/plant-science/diatoms-applications-environmental-and-earth-sciences-2nd-edition},
	author = {Sarah A. Spaulding and Bart Van de Vijver and Hodgson, D and Diane M. McKnight and Elie Verleyen and Lee F. Stanish}
}
