<?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%">John E. Barrett</style></author><author><style face="normal" font="default" size="100%">Ross A. Virginia</style></author><author><style face="normal" font="default" size="100%">W. Berry Lyons</style></author><author><style face="normal" font="default" size="100%">Diane M. McKnight</style></author><author><style face="normal" font="default" size="100%">John C. Priscu</style></author><author><style face="normal" font="default" size="100%">Andrew G Fountain</style></author><author><style face="normal" font="default" size="100%">Diana H. Wall</style></author><author><style face="normal" font="default" size="100%">Daryl L. Moorhead</style></author><author><style face="normal" font="default" size="100%">Peter T. Doran</style></author></authors></contributors><titles><title><style face="normal" font="default" size="100%">Biogeochemical stoichiometry of Antarctic Dry Valley ecosystems</style></title><secondary-title><style face="normal" font="default" size="100%">Journal of Geophysical Research</style></secondary-title></titles><keywords><keyword><style  face="normal" font="default" size="100%">Biggie</style></keyword></keywords><dates><year><style  face="normal" font="default" size="100%">2007</style></year><pub-dates><date><style  face="normal" font="default" size="100%">02/2007</style></date></pub-dates></dates><volume><style face="normal" font="default" size="100%">112</style></volume><pages><style face="normal" font="default" size="100%">G01010+12</style></pages><language><style face="normal" font="default" size="100%">eng</style></language><abstract><style face="normal" font="default" size="100%">&lt;p&gt;&lt;span style=&quot;color: rgb(51, 51, 51); font-family: 'Open Sans', Arial, Helvetica, 'Lucida Sans Unicode', sans-serif; font-size: 16px; line-height: 24px; background-color: rgb(249, 249, 249);&quot;&gt;Among aquatic and terrestrial landscapes of the McMurdo Dry Valleys, Antarctica, ecosystem stoichiometry ranges from values near the Redfield ratios for C:N:P to nutrient concentrations in proportions far above or below ratios necessary to support balanced microbial growth. This polar desert provides an opportunity to evaluate stoichiometric approaches to understand nutrient cycling in an ecosystem where biological diversity and activity are low, and controls over the movement and mass balances of nutrients operate over 10&amp;ndash;10&lt;/span&gt;&lt;span style=&quot;line-height: 0; top: -0.5em; padding-right: 1px; padding-left: 1px; outline: 0px; font-size: 0.688em; position: relative; color: rgb(51, 51, 51); font-family: 'Open Sans', Arial, Helvetica, 'Lucida Sans Unicode', sans-serif; background: 0px 0px rgb(249, 249, 249);&quot;&gt;6&lt;/span&gt;&lt;span style=&quot;color: rgb(51, 51, 51); font-family: 'Open Sans', Arial, Helvetica, 'Lucida Sans Unicode', sans-serif; font-size: 16px; line-height: 24px; background-color: rgb(249, 249, 249);&quot;&gt;&amp;nbsp;years. The simple organisms (microbial and metazoan) comprising dry valley foodwebs adhere to strict biochemical requirements in the composition of their biomass, and when activated by availability of liquid water, they influence the chemical composition of their environment according to these ratios. Nitrogen and phosphorus varied significantly in terrestrial and aquatic ecosystems occurring on landscape surfaces across a wide range of exposure ages, indicating strong influences of landscape development and geochemistry on nutrient availability. Biota control the elemental ratio of stream waters, while geochemical stoichiometry (e.g., weathering, atmospheric deposition) evidently limits the distribution of soil invertebrates. We present a conceptual model describing transformations across dry valley landscapes facilitated by exchanges of liquid water and biotic processing of dissolved nutrients. We conclude that contemporary ecosystem stoichiometry of Antarctic Dry Valley soils, glaciers, streams, and lakes results from a combination of extant biological processes superimposed on a legacy of landscape processes and previous climates.&lt;/span&gt;&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%">Rhea M.M. Esposito</style></author><author><style face="normal" font="default" size="100%">Horn, S</style></author><author><style face="normal" font="default" size="100%">Diane M. McKnight</style></author><author><style face="normal" font="default" size="100%">Cox, M</style></author><author><style face="normal" font="default" size="100%">Grant, M</style></author><author><style face="normal" font="default" size="100%">Sarah A. Spaulding</style></author><author><style face="normal" font="default" size="100%">Peter T. Doran</style></author><author><style face="normal" font="default" size="100%">Cozzetto, K</style></author></authors></contributors><titles><title><style face="normal" font="default" size="100%">Antarctic Climate Cooling and Response of Diatoms in Glacial Meltwater Streams</style></title><secondary-title><style face="normal" font="default" size="100%">Geophysical Research Letters</style></secondary-title></titles><keywords><keyword><style  face="normal" font="default" size="100%">Biggie</style></keyword></keywords><dates><year><style  face="normal" font="default" size="100%">2006</style></year><pub-dates><date><style  face="normal" font="default" size="100%">04/2006</style></date></pub-dates></dates><volume><style face="normal" font="default" size="100%">33</style></volume><pages><style face="normal" font="default" size="100%">L07406</style></pages><language><style face="normal" font="default" size="100%">eng</style></language><abstract><style face="normal" font="default" size="100%">&lt;p&gt;&lt;span style=&quot;color: rgb(51, 51, 51); font-family: 'Open Sans', Arial, Helvetica, 'Lucida Sans Unicode', sans-serif; font-size: 16px; line-height: 24px; background-color: rgb(249, 249, 249);&quot;&gt;To understand biotic responses to an Antarctic cooling trend, we analyzed diatom samples from glacial meltwater streams in the McMurdo Dry Valleys, the largest ice-free area in Antarctica. Diatoms are abundant in these streams, and 24 of 40 species have only been found in the Antarctic. The percentage of these Antarctic diatom species increased with decreasing annual stream flow and increasing harshness of the stream habitat. The species diversity of assemblages reached a maximum when the Antarctic species accounted for 40&amp;ndash;60% of relative diatom abundance. Decreased solar radiation and air-temperatures reduce annual stream flow, raising the dominance of these Antarctic species to levels above 60%. Thus, cooling favors the Antarctic species, and lowers diatom species diversity in this region.&lt;/span&gt;&lt;/p&gt;</style></abstract><work-type><style face="normal" font="default" size="100%">Journal</style></work-type></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%">Michael N. Gooseff</style></author><author><style face="normal" font="default" size="100%">John E. Barrett</style></author><author><style face="normal" font="default" size="100%">Peter T. Doran</style></author><author><style face="normal" font="default" size="100%">Andrew G Fountain</style></author><author><style face="normal" font="default" size="100%">W. Berry Lyons</style></author><author><style face="normal" font="default" size="100%">Andrew N. Parsons</style></author><author><style face="normal" font="default" size="100%">Porazinska, D</style></author><author><style face="normal" font="default" size="100%">Ross A. Virginia</style></author><author><style face="normal" font="default" size="100%">Diana H. Wall</style></author></authors></contributors><titles><title><style face="normal" font="default" size="100%">Snow patch influence on soil biogeochemical processes and invertebrate distribution in the McMurdo Dry Valleys, Antarctica</style></title><secondary-title><style face="normal" font="default" size="100%">Arctic, Antarctic, and Alpine Research</style></secondary-title></titles><keywords><keyword><style  face="normal" font="default" size="100%">Biggie</style></keyword></keywords><dates><year><style  face="normal" font="default" size="100%">2002</style></year><pub-dates><date><style  face="normal" font="default" size="100%">02/2003</style></date></pub-dates></dates><urls><web-urls><url><style face="normal" font="default" size="100%">http://instaar.metapress.com/content/r086455ju7213711/</style></url></web-urls></urls><volume><style face="normal" font="default" size="100%">35</style></volume><pages><style face="normal" font="default" size="100%">91-99</style></pages><language><style face="normal" font="default" size="100%">eng</style></language><issue><style face="normal" font="default" size="100%">1</style></issue><work-type><style face="normal" font="default" size="100%">Journal</style></work-type><accession-num><style face="normal" font="default" size="100%">LTER49857</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%">Peter T. Doran</style></author><author><style face="normal" font="default" size="100%">Christopher P. McKay</style></author><author><style face="normal" font="default" size="100%">Gary D. Clow</style></author><author><style face="normal" font="default" size="100%">Gayle L. Dana</style></author><author><style face="normal" font="default" size="100%">Andrew G Fountain</style></author><author><style face="normal" font="default" size="100%">Thomas H. Nylen</style></author><author><style face="normal" font="default" size="100%">W. Berry Lyons</style></author></authors></contributors><titles><title><style face="normal" font="default" size="100%">Valley floor climate observations from the McMurdo Dry Valleys, Antarctica, 1986-2000</style></title><secondary-title><style face="normal" font="default" size="100%">Journal of Geophysical Research</style></secondary-title></titles><keywords><keyword><style  face="normal" font="default" size="100%">Biggie</style></keyword></keywords><dates><year><style  face="normal" font="default" size="100%">2002</style></year><pub-dates><date><style  face="normal" font="default" size="100%">12/2002</style></date></pub-dates></dates><volume><style face="normal" font="default" size="100%">107</style></volume><pages><style face="normal" font="default" size="100%">4772-4784</style></pages><language><style face="normal" font="default" size="100%">eng</style></language><abstract><style face="normal" font="default" size="100%">&lt;p&gt;&lt;span style=&quot;color: rgb(51, 51, 51); font-family: 'Open Sans', Arial, Helvetica, 'Lucida Sans Unicode', sans-serif; font-size: 16px; line-height: 24px; background-color: rgb(249, 249, 249);&quot;&gt;Climate observations from the McMurdo dry valleys, East Antarctica are presented from a network of seven valley floor automatic meteorological stations during the period 1986 to 2000. Mean annual temperatures ranged from &amp;minus;14.8&amp;deg;C to &amp;minus;30.0&amp;deg;C, depending on the site and period of measurement. Mean annual relative humidity is generally highest near the coast. Mean annual wind speed increases with proximity to the polar plateau. Site-to-site variation in mean annual solar flux and PAR is due to exposure of each station and changes over time are likely related to changes in cloudiness. During the nonsummer months, strong katabatic winds are frequent at some sites and infrequent at others, creating large variation in mean annual temperature owing to the warming effect of the winds. Katabatic wind exposure appears to be controlled to a large degree by the presence of colder air in the region that collects at low points and keeps the warm less dense katabatic flow from the ground. The strong influence of katabatic winds makes prediction of relative mean annual temperature based on geographical position (elevation and distance from the coast) alone, not possible. During the summer months, onshore winds dominate and warm as they progress through the valleys creating a strong linear relationship (r&lt;/span&gt;&lt;span style=&quot;line-height: 0; top: -0.5em; padding-right: 1px; padding-left: 1px; outline: 0px; font-size: 0.688em; position: relative; color: rgb(51, 51, 51); font-family: 'Open Sans', Arial, Helvetica, 'Lucida Sans Unicode', sans-serif; background: 0px 0px rgb(249, 249, 249);&quot;&gt;2&lt;/span&gt;&lt;span style=&quot;color: rgb(51, 51, 51); font-family: 'Open Sans', Arial, Helvetica, 'Lucida Sans Unicode', sans-serif; font-size: 16px; line-height: 24px; background-color: rgb(249, 249, 249);&quot;&gt;&amp;nbsp;= 0.992) of increasing potential temperature with distance from the coast (0.09&amp;deg;C km&lt;/span&gt;&lt;span style=&quot;line-height: 0; top: -0.5em; padding-right: 1px; padding-left: 1px; outline: 0px; font-size: 0.688em; position: relative; color: rgb(51, 51, 51); font-family: 'Open Sans', Arial, Helvetica, 'Lucida Sans Unicode', sans-serif; background: 0px 0px rgb(249, 249, 249);&quot;&gt;&amp;minus;1&lt;/span&gt;&lt;span style=&quot;color: rgb(51, 51, 51); font-family: 'Open Sans', Arial, Helvetica, 'Lucida Sans Unicode', sans-serif; font-size: 16px; line-height: 24px; background-color: rgb(249, 249, 249);&quot;&gt;). In contrast to mean annual temperature, summer temperature lends itself quite well to model predictions, and is used to construct a statistical model for predicting summer dry valley temperatures at unmonitored sites.&lt;/span&gt;&lt;/p&gt;</style></abstract><issue><style face="normal" font="default" size="100%">4772</style></issue><work-type><style face="normal" font="default" size="100%">Journal</style></work-type><accession-num><style face="normal" font="default" size="100%">LTER49856</style></accession-num></record><record><source-app name="Biblio" version="7.x">Drupal-Biblio</source-app><ref-type>5</ref-type><contributors><authors><author><style face="normal" font="default" size="100%">Peter T. Doran</style></author><author><style face="normal" font="default" size="100%">Peter Adams</style></author><author><style face="normal" font="default" size="100%">Ecclestone, M</style></author></authors><tertiary-authors><author><style face="normal" font="default" size="100%">A. G. Lewkowicz</style></author></tertiary-authors></contributors><titles><title><style face="normal" font="default" size="100%">Arctic and Antarctic lakes: contrast or continuum?</style></title><secondary-title><style face="normal" font="default" size="100%">Poles Apart: A Study in Contrasts</style></secondary-title></titles><keywords><keyword><style  face="normal" font="default" size="100%">Biggie</style></keyword></keywords><dates><year><style  face="normal" font="default" size="100%">1999</style></year></dates><publisher><style face="normal" font="default" size="100%">University of Ottawa Press</style></publisher><pages><style face="normal" font="default" size="100%">59-68</style></pages><language><style face="normal" font="default" size="100%">eng</style></language></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%">Christian H. Fritsen</style></author><author><style face="normal" font="default" size="100%">Edward E. Adams</style></author><author><style face="normal" font="default" size="100%">Stephen J. Giovannoni</style></author><author><style face="normal" font="default" size="100%">Hans W. Paerl</style></author><author><style face="normal" font="default" size="100%">Christopher P. McKay</style></author><author><style face="normal" font="default" size="100%">Peter T. Doran</style></author><author><style face="normal" font="default" size="100%">Douglas A. Gordon</style></author><author><style face="normal" font="default" size="100%">Brian D. Lanoil</style></author><author><style face="normal" font="default" size="100%">James L. Pinckney</style></author></authors></contributors><titles><title><style face="normal" font="default" size="100%">Perennial Antarctic Lake Ice:  An Oasis for Life in a Polar Desert</style></title><secondary-title><style face="normal" font="default" size="100%">Science</style></secondary-title></titles><keywords><keyword><style  face="normal" font="default" size="100%">Biggie</style></keyword></keywords><dates><year><style  face="normal" font="default" size="100%">1998</style></year><pub-dates><date><style  face="normal" font="default" size="100%">06/1998</style></date></pub-dates></dates><urls><web-urls><url><style face="normal" font="default" size="100%">http://www.sciencemag.org/content/280/5372/2095.short</style></url></web-urls></urls><volume><style face="normal" font="default" size="100%">280</style></volume><pages><style face="normal" font="default" size="100%">2095-2098</style></pages><language><style face="normal" font="default" size="100%">eng</style></language><issue><style face="normal" font="default" size="100%">5372</style></issue><work-type><style face="normal" font="default" size="100%">Journal</style></work-type><accession-num><style face="normal" font="default" size="100%">LTER12940</style></accession-num></record></records></xml>