<?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%">Trista J. Vick-Majors</style></author><author><style face="normal" font="default" size="100%">John C. Priscu</style></author></authors></contributors><titles><title><style face="normal" font="default" size="100%">Inorganic carbon fixation in ice-covered lakes of the McMurdo Dry Valleys</style></title><secondary-title><style face="normal" font="default" size="100%">Antarctic Science</style></secondary-title><short-title><style face="normal" font="default" size="100%">Antarctic Science</style></short-title></titles><keywords><keyword><style  face="normal" font="default" size="100%">ammonia oxidation</style></keyword><keyword><style  face="normal" font="default" size="100%">carbon budget</style></keyword><keyword><style  face="normal" font="default" size="100%">chemoautotrophy</style></keyword><keyword><style  face="normal" font="default" size="100%">chemolithoautotrophy</style></keyword></keywords><dates><year><style  face="normal" font="default" size="100%">2019</style></year><pub-dates><date><style  face="normal" font="default" size="100%">04/2019</style></date></pub-dates></dates><urls><web-urls><url><style face="normal" font="default" size="100%">https://www.cambridge.org/core/journals/antarctic-science/article/inorganic-carbon-fixation-in-icecovered-lakes-of-the-mcmurdo-dry-valleys/4B5CA9E91C85B307EFDA69F8D7B5BFD9</style></url></web-urls></urls><volume><style face="normal" font="default" size="100%">72</style></volume><language><style face="normal" font="default" size="100%">eng</style></language><abstract><style face="normal" font="default" size="100%">&lt;p&gt;Inorganic carbon fixation, usually mediated by photosynthetic microorganisms, is considered to form the base of the food chain in aquatic ecosystems. In high-latitude lakes, lack of sunlight owing to seasonal solar radiation limits the activity of photosynthetic plankton during the polar winter, causing respiration-driven demand for carbon to exceed supply. Here, we show that inorganic carbon fixation in the dark, driven by organisms that gain energy from chemical reactions rather than sunlight (chemolithoautotrophs), provides a significant influx of fixed carbon to two permanently ice-covered lakes (Fryxell and East Bonney). Fryxell, which has higher biomass per unit volume of water, had higher rates of inorganic dark carbon fixation by chemolithoautotrophs than East Bonney (trophogenic zone average 1.0 &amp;micro;g C l&lt;sup&gt;&amp;minus;1&lt;/sup&gt; d&lt;sup&gt;&amp;minus;1&amp;nbsp;&lt;/sup&gt;vs 0.08 &amp;micro;g C l&lt;sup&gt;&amp;minus;1&lt;/sup&gt; d&lt;sup&gt;&amp;minus;1&lt;/sup&gt;, respectively). This contribution from dark carbon fixation was partly due to the activity of ammonia oxidizers, which are present in both lakes. Despite the potential importance of new carbon input by chemolithoautotrophic activity, both lakes remain net heterotrophic, with respiratory demand for carbon exceeding supply. Dark carbon fixation increased the ratio of new carbon supply to respiratory demand from 0.16 to 0.47 in Fryxell, and from 0.14 to 0.22 in East Bonney.&lt;/p&gt;</style></abstract></record><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%">Andrew G Fountain</style></author><author><style face="normal" font="default" size="100%">Saba, Grace</style></author><author><style face="normal" font="default" size="100%">Byron Adams</style></author><author><style face="normal" font="default" size="100%">Peter T. Doran</style></author><author><style face="normal" font="default" size="100%">Fraser, William</style></author><author><style face="normal" font="default" size="100%">Michael N. Gooseff</style></author><author><style face="normal" font="default" size="100%">Maciek K. Obryk</style></author><author><style face="normal" font="default" size="100%">John C. Priscu</style></author><author><style face="normal" font="default" size="100%">Sharon E. Stammerjohn</style></author><author><style face="normal" font="default" size="100%">Ross A. Virginia</style></author></authors></contributors><titles><title><style face="normal" font="default" size="100%">The Impact of a Large-Scale Climate Event on Antarctic Ecosystem Processes</style></title><secondary-title><style face="normal" font="default" size="100%">BioScience</style></secondary-title></titles><dates><year><style  face="normal" font="default" size="100%">2016</style></year><pub-dates><date><style  face="normal" font="default" size="100%">10/2016</style></date></pub-dates></dates><urls><web-urls><url><style face="normal" font="default" size="100%">http://academic.oup.com/bioscience/article-pdf/66/10/848/7510601/biw110.pdf</style></url></web-urls></urls><volume><style face="normal" font="default" size="100%">66</style></volume><pages><style face="normal" font="default" size="100%">848 - 863</style></pages><language><style face="normal" font="default" size="100%">eng</style></language><abstract><style face="normal" font="default" size="100%">&lt;p&gt;Extreme climate and weather events, such as a drought, hurricanes, or ice storms, can strongly imprint ecosystem processing and may alter ecosystem structure. Ecosystems in extreme environments are particularly vulnerable because of their adaptation to severe limitations in energy, water, or nutrients. The vulnerability can be expressed as a relatively long-lasting ecosystem response to a small or brief change in environmental conditions. Such an event occurred in Antarctica and affected two vastly different ecosystems: a marine-dominated coastal system and a terrestrial polar desert. Both sites experienced winds that warmed air temperatures above the 0&amp;deg;C threshold, resulting in extensive snow and ice melt and triggering a series of cascading effects through the ecosystems that are continuing to play out more than a decade later. This highlights the sensitivity of Antarctic ecosystems to warming events, which should occur more frequently in the future with global climate warming.&lt;/p&gt;</style></abstract><issue><style face="normal" font="default" size="100%">10</style></issue></record><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%">Pocock, T</style></author><author><style face="normal" font="default" size="100%">Lachance, M</style></author><author><style face="normal" font="default" size="100%">Proschold, T</style></author><author><style face="normal" font="default" size="100%">John C. Priscu</style></author><author><style face="normal" font="default" size="100%">Kim, S</style></author><author><style face="normal" font="default" size="100%">Norman P.A. Huner</style></author></authors></contributors><titles><title><style face="normal" font="default" size="100%">Identification of a psychrophilic green alga from Lake Bonney, Antarctica: Chlamydomonas raudensis ETTL. (UWO 241) (Chlorophyceae)</style></title><secondary-title><style face="normal" font="default" size="100%">Journal of Phycology</style></secondary-title></titles><dates><year><style  face="normal" font="default" size="100%">2004</style></year></dates><volume><style face="normal" font="default" size="100%">40</style></volume><pages><style face="normal" font="default" size="100%">1138-1148</style></pages><language><style face="normal" font="default" size="100%">eng</style></language><issue><style face="normal" font="default" size="100%">6</style></issue><accession-num><style face="normal" font="default" size="100%">LTER63380</style></accession-num></record><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%">Christine M. Foreman</style></author><author><style face="normal" font="default" size="100%">Wolf, C</style></author><author><style face="normal" font="default" size="100%">John C. Priscu</style></author></authors></contributors><titles><title><style face="normal" font="default" size="100%">Impact of episodic warming events on the physical, chemical and biological relationships of lakes in the McMurdo Dry Valleys, Antarctica</style></title><secondary-title><style face="normal" font="default" size="100%">Aquatic Geochemistry</style></secondary-title></titles><keywords><keyword><style  face="normal" font="default" size="100%">Climate Response</style></keyword><keyword><style  face="normal" font="default" size="100%">stoichiometry</style></keyword></keywords><dates><year><style  face="normal" font="default" size="100%">2004</style></year><pub-dates><date><style  face="normal" font="default" size="100%">09/2004</style></date></pub-dates></dates><urls><web-urls><url><style face="normal" font="default" size="100%">http://link.springer.com/article/10.1007%2Fs10498-004-2261-3</style></url></web-urls></urls><volume><style face="normal" font="default" size="100%">10</style></volume><pages><style face="normal" font="default" size="100%">239-268</style></pages><language><style face="normal" font="default" size="100%">eng</style></language><issue><style face="normal" font="default" size="100%">3-4</style></issue><work-type><style face="normal" font="default" size="100%">Journal</style></work-type><accession-num><style face="normal" font="default" size="100%">LTER63365</style></accession-num></record><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%">W. Berry Lyons</style></author><author><style face="normal" font="default" size="100%">Andrew G Fountain</style></author><author><style face="normal" font="default" size="100%">Peter T. Doran</style></author><author><style face="normal" font="default" size="100%">John C. Priscu</style></author><author><style face="normal" font="default" size="100%">Klaus Neumann</style></author><author><style face="normal" font="default" size="100%">Kathleen A. Welch</style></author></authors></contributors><titles><title><style face="normal" font="default" size="100%">The importance of landscape position and legacy: The evolution of the Taylor  Valley Lake District, Antarctica.</style></title><secondary-title><style face="normal" font="default" size="100%">Freshwater Biology</style></secondary-title></titles><dates><year><style  face="normal" font="default" size="100%">2000</style></year></dates><volume><style face="normal" font="default" size="100%">43</style></volume><pages><style face="normal" font="default" size="100%">355-367</style></pages><language><style face="normal" font="default" size="100%">eng</style></language><accession-num><style face="normal" font="default" size="100%">LTER49553</style></accession-num></record><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%">Richard D.  Bartlett</style></author><author><style face="normal" font="default" size="100%">John C. Priscu</style></author><author><style face="normal" font="default" size="100%">Christopher D. Woolston</style></author></authors></contributors><titles><title><style face="normal" font="default" size="100%">Influence of high salinity levels on ambient inorganic nitrogen and nitrogen-15 extraction efficiency in Lake Bonney</style></title><secondary-title><style face="normal" font="default" size="100%">Antarctic Journal of the U.S.</style></secondary-title></titles><dates><year><style  face="normal" font="default" size="100%">1993</style></year></dates><volume><style face="normal" font="default" size="100%">28</style></volume><pages><style face="normal" font="default" size="100%">245-246</style></pages><language><style face="normal" font="default" size="100%">eng</style></language><issue><style face="normal" font="default" size="100%">5</style></issue><accession-num><style face="normal" font="default" size="100%">LTER12788</style></accession-num></record><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%">John C. Priscu</style></author><author><style face="normal" font="default" size="100%">Warwick F. Vincent</style></author><author><style face="normal" font="default" size="100%">Clive Howard-Williams</style></author></authors></contributors><titles><title><style face="normal" font="default" size="100%">Inorganic Nitrogen Uptake and Regeneration in Perennially Ice-Covered Lakes Fryxell and Vanda, Antarctica</style></title><secondary-title><style face="normal" font="default" size="100%">Journal of Plankton Research</style></secondary-title></titles><dates><year><style  face="normal" font="default" size="100%">1989</style></year></dates><volume><style face="normal" font="default" size="100%">11</style></volume><pages><style face="normal" font="default" size="100%">335-351</style></pages><language><style face="normal" font="default" size="100%">eng</style></language><issue><style face="normal" font="default" size="100%">2</style></issue><accession-num><style face="normal" font="default" size="100%">LTER12929</style></accession-num></record></records></xml>