<?xml version="1.0" encoding="UTF-8"?><xml><records><record><source-app name="Biblio" version="7.x">Drupal-Biblio</source-app><ref-type>17</ref-type><contributors><authors><author><style face="normal" font="default" size="100%">Singley, Joel G.</style></author><author><style face="normal" font="default" size="100%">Salvatore, Mark R.</style></author><author><style face="normal" font="default" size="100%">Michael N. Gooseff</style></author><author><style face="normal" font="default" size="100%">Diane M. McKnight</style></author><author><style face="normal" font="default" size="100%">Eve-Lyn S. Hinckley</style></author></authors></contributors><titles><title><style face="normal" font="default" size="100%">Differentiating physical and biological storage of nitrogen along an intermittent Antarctic stream corridor</style></title><secondary-title><style face="normal" font="default" size="100%">Freshwater Science</style></secondary-title><short-title><style face="normal" font="default" size="100%">Freshwater Science</style></short-title></titles><keywords><keyword><style  face="normal" font="default" size="100%">hyporheic zone</style></keyword><keyword><style  face="normal" font="default" size="100%">McMurdo LTER</style></keyword><keyword><style  face="normal" font="default" size="100%">nitrogen cycling</style></keyword><keyword><style  face="normal" font="default" size="100%">nutrient budget</style></keyword><keyword><style  face="normal" font="default" size="100%">organic matter</style></keyword><keyword><style  face="normal" font="default" size="100%">periphyton</style></keyword></keywords><dates><year><style  face="normal" font="default" size="100%">2023</style></year><pub-dates><date><style  face="normal" font="default" size="100%">09/2023</style></date></pub-dates></dates><urls><web-urls><url><style face="normal" font="default" size="100%">https://www.journals.uchicago.edu/doi/10.1086/725676</style></url></web-urls></urls><volume><style face="normal" font="default" size="100%">42</style></volume><language><style face="normal" font="default" size="100%">eng</style></language><abstract><style face="normal" font="default" size="100%">&lt;p&gt;In many temperate streams, biological uptake of N acts to attenuate the transport of excess N from allochthonous anthropogenic imports. Relatively few studies have determined how this N uptake relates to the magnitude of physical vs. biological N storage in the stream corridor, especially for intermittent systems where allochthonous N imports are often low and N transport may only occur during brief periods of streamflow. Glacial meltwater streams in the McMurdo Dry Valleys of Antarctica provide an excellent setting to quantify autochthonous N cycling and storage processes supported by abundant algal mats and well-connected hyporheic zones. We combined historic point-scale sediment and periphyton sample datasets with remote sensing-based modeling of periphyton coverage to estimate how much N was stored in periphyton biomass and the hyporheic zone of a 5-km long McMurdo Dry Valley stream corridor (&amp;gt;100,000 m&lt;sup&gt;2&lt;/sup&gt;). We contextualized these N storage calculations by estimating the magnitude of annual N imports to and exports from the stream corridor based on &amp;gt;2 decades of streamflow and surface water data, source glacier ice cores and meltwater data, and past studies of local aeolian deposition and biological N fixation rates. We found that in this highly oligotrophic system, stream corridor-scale N storage was ~1000x that of total annual N import or export fluxes. More than 90% of this temporarily stored N was autochthonous organic matter in the shallow (&amp;lt;10 cm) hyporheic zone, which acts as a reservoir that sustains N availability in the water column. Despite its location in a polar desert devoid of higher-order vegetation, area-normalized N storage (~40 g N/m&lt;sup&gt;2&lt;/sup&gt;) was greater than that reported for streams at lower latitudes (~1&amp;ndash;22 g N/m&lt;sup&gt;2&lt;/sup&gt;). We also demonstrated that NH&lt;sub&gt;4&lt;/sub&gt;&lt;sup&gt;+&lt;/sup&gt; sorption to stream sediment may be an important physicochemical N storage mechanism that responds to short-term fluctuations in streamflow and governs the mobility of inorganic N. Altogether, this research illustrates the importance of quantifying N storage within stream corridors when evaluating the significance of internal cycling and physical retention processes that modulate N availability.&lt;/p&gt;</style></abstract><issue><style face="normal" font="default" size="100%">3</style></issue></record></records></xml>