<?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%">Ball, Becky</style></author><author><style face="normal" font="default" size="100%">Byron Adams</style></author><author><style face="normal" font="default" size="100%">John E. Barrett</style></author><author><style face="normal" font="default" size="100%">Diana H. Wall</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%">Soil biological responses to C, N and P fertilization in a polar desert of Antarctica</style></title><secondary-title><style face="normal" font="default" size="100%">Soil Biology and Biochemistry</style></secondary-title><short-title><style face="normal" font="default" size="100%">Soil Biology and Biochemistry</style></short-title></titles><dates><year><style  face="normal" font="default" size="100%">2018</style></year><pub-dates><date><style  face="normal" font="default" size="100%">07/2018</style></date></pub-dates></dates><urls><web-urls><url><style face="normal" font="default" size="100%">http://linkinghub.elsevier.com/retrieve/pii/S0038071718301081</style></url></web-urls></urls><volume><style face="normal" font="default" size="100%">122</style></volume><language><style face="normal" font="default" size="100%">eng</style></language><abstract><style face="normal" font="default" size="100%">&lt;p&gt;&amp;nbsp;&lt;/p&gt;&lt;div title=&quot;Page 1&quot;&gt;&lt;div&gt;&lt;div&gt;&lt;p&gt;In the polar desert ecosystem of the McMurdo Dry Valleys of Antarctica, biology is constrained by available liquid water, low temperatures, as well as the availability of organic matter and nutrient elements. These soil ecosystems are climate-sensitive, where projected future warming may have profound effects on biological communities and biogeochemical cycling. Warmer temperatures will mobilize meltwater from permafrost and glaciers, may increase precipitation and may be accompanied by pulses of nutrient availability. Enhanced water and nutrient availability have the potential to greatly influence desert soil biology and ecosystem processes. The objectives of this 5-year study were to determine which nutrient elements (C, N, P) are most limiting to dry valley soil communities and whether landscape history (i.e.,&amp;nbsp;in situ&amp;nbsp;soil type and stoichiometry) influences soil community response to nutrient additions. After 3 years of no noticeable response, soil CO2&amp;nbsp;flux was significantly higher under addition of C+ N than the other treatments, regardless of&amp;nbsp;in situ&amp;nbsp;soil stoichiometry, but microbial biomass and invertebrate abundance were variable and not influenced in the same manner. A stable isotope incubation suggests that fertilization increases C and N mineralization from organic matter via stimulating microbial activity, with loss of both the applied treatments as well&amp;nbsp;in situ&amp;nbsp;C and N. However, these responses are relatively short-lived, suggesting long-term impacts on C and N cycling would only occur if meltwater and nutrient pulses are sustained over time, a scenario that is increasingly likely for the dry valleys.&lt;/p&gt;&lt;/div&gt;&lt;/div&gt;&lt;/div&gt;&lt;p&gt;&amp;nbsp;&lt;/p&gt;</style></abstract><section><style face="normal" font="default" size="100%">7</style></section></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%">Aanderud, Zachary T.</style></author><author><style face="normal" font="default" size="100%">Saurey, Sabrina D.</style></author><author><style face="normal" font="default" size="100%">Ball, Becky</style></author><author><style face="normal" font="default" size="100%">Diana H. Wall</style></author><author><style face="normal" font="default" size="100%">John E. Barrett</style></author><author><style face="normal" font="default" size="100%">Muscarella, Mario E.</style></author><author><style face="normal" font="default" size="100%">Griffin, Natasha A.</style></author><author><style face="normal" font="default" size="100%">Ross A. Virginia</style></author><author><style face="normal" font="default" size="100%">Byron Adams</style></author></authors></contributors><titles><title><style face="normal" font="default" size="100%">Stoichiometric Shifts in Soil C:N:P Promote Bacterial Taxa Dominance, Maintain Biodiversity, and Deconstruct Community Assemblages</style></title><secondary-title><style face="normal" font="default" size="100%">Frontiers in Microbiology</style></secondary-title><short-title><style face="normal" font="default" size="100%">Front. Microbiol.</style></short-title></titles><keywords><keyword><style  face="normal" font="default" size="100%">ecological stoichiometry</style></keyword><keyword><style  face="normal" font="default" size="100%">Lake Fryxell Basin</style></keyword><keyword><style  face="normal" font="default" size="100%">McMurdo Dry Valleys</style></keyword><keyword><style  face="normal" font="default" size="100%">network community modeling</style></keyword><keyword><style  face="normal" font="default" size="100%">nutrient colimitation</style></keyword><keyword><style  face="normal" font="default" size="100%">Solirubrobacteriaceae</style></keyword></keywords><dates><year><style  face="normal" font="default" size="100%">2018</style></year><pub-dates><date><style  face="normal" font="default" size="100%">07/2018</style></date></pub-dates></dates><urls><web-urls><url><style face="normal" font="default" size="100%">https://www.frontiersin.org/article/10.3389/fmicb.2018.01401/full</style></url></web-urls></urls><volume><style face="normal" font="default" size="100%">9</style></volume><language><style face="normal" font="default" size="100%">eng</style></language><abstract><style face="normal" font="default" size="100%">&lt;p&gt;Imbalances in C:N:P supply ratios may cause bacterial resource limitations and constrain biogeochemical processes, but the importance of shifts in soil stoichiometry are complicated by the nearly limitless interactions between an immensely rich species pool and a multiple chemical resource forms. To more clearly identify the impact of soil C:N:P on bacteria, we evaluated the cumulative effects of single and coupled long-term nutrient additions (i.e., C as mannitol, N as equal concentrations NH4 + and NO3 &amp;minus; , and P as Na3PO4) and water on communities in an Antarctic polar desert, Taylor Valley. Untreated soils possessed relatively low bacterial diversity, simplified organic C sources due to the absence of plants, limited inorganic N, and excess soil P potentially attenuating links between C:N:P. After 6 years of adding resources, an alleviation of C and N colimitation allowed one rare Micrococcaceae, an Arthrobacter species, to dominate, comprising 47% of the total community abundance and elevating soil respiration by 136% relative to untreated soils. The addition of N alone reduced C:N ratios, elevated bacterial richness and diversity, and allowed rare taxa relying on ammonium and nitrite for metabolism to become more abundant [e.g., nitrite oxidizing Nitrospira species (Nitrosomonadaceae), denitrifiers utilizing nitrite (Gemmatimonadaceae) and members of Rhodobacteraceae with a high affinity for ammonium]. Based on community co-occurrence networks, lower C:P ratios in soils following P and CP additions created more diffuse and less connected communities by disrupting 73% of species interactions and selecting for taxa potentially exploiting abundant P. Unlike amended nutrients, water additions alone elicited no lasting impact on communities. Our results suggest that as soils become nutrient rich a wide array of outcomes are possible from species dominance and the deconstruction of species interconnectedness to the maintenance of biodiversity.&lt;/p&gt;</style></abstract></record></records></xml>