@article {1054,
	title = {Bacterial community composition of divergent soil habitats from a polar desert.},
	journal = {FEMS Microbiology Ecology},
	volume = {89},
	year = {2014},
	month = {08/2014},
	pages = {490-494},
	type = {Short Communication},
	chapter = {490},
	abstract = {Edaphic factors such as pH, organic matter, and salinity are often the most significant drivers of diversity patterns in soil bacterial communities. Desert ecosystems in particular are model locations for examining such relationships as food web complexity is low and the soil environment is biogeochemically heterogeneous. Here, we present the findings from a 16S rRNA gene sequencing approach used to observe the differences in diversity and community composition among three divergent soil habitats of the McMurdo Dry Valleys, Antarctica. Results show that alpha diversity is significantly lowered in high pH soils, which contain higher proportions of the phyla Acidobacteria and Actinobacteria, while mesic soils with higher soil organic carbon (and ammonium) content contain high proportions of Nitrospira, a nitrite-oxidizing bacteria. Taxonomic community resolution also had a significant impact on our conclusions, as pH was the primary predictor of phylum-level diversity, while moisture was the most significant predictor of diversity at the genus level. Predictive power also increased with increasing taxonomic resolution, suggesting a potential increase in nic},
	keywords = {LTER-MCM},
	doi = {10.1111/1574-6941.12306},
	author = {Kevin M. Geyer and Adam E. Altrichter and Cristina D. Takacs-Vesbach and Michael N. Gooseff and John E. Barrett}
}
@article {1084,
	title = {Environmental controls over bacterial communities in polar desert soils},
	journal = {Ecosphere},
	volume = {4},
	year = {2013},
	month = {10/2013},
	pages = {art127},
	keywords = {LTER-MCM},
	doi = {10.1890/ES13-00048.1},
	author = {Kevin M. Geyer and Adam E. Altrichter and David J. Van Horn and Cristina D. Takacs-Vesbach and Michael N. Gooseff and John E. Barrett}
}
@article {1092,
	title = {Factors Controlling Soil Microbial Biomass and Bacterial Diversity and Community Composition in a Cold Desert Ecosystem: Role of Geographic Scale},
	journal = {PLoS ONE},
	volume = {8},
	year = {2013},
	month = {06/2013},
	pages = {e66103},
	keywords = {LTER-MCM},
	doi = {10.1371/journal.pone.0066103.s003},
	url = {http://www.plosone.org/article/info\%3Adoi\%2F10.1371\%2Fjournal.pone.0066103},
	author = {David J. Van Horn and Van Horn, M. Lee and John E. Barrett and Michael N. Gooseff and Adam E. Altrichter and Kevin M. Geyer and Lydia H. Zeglin and Cristina D. Takacs-Vesbach}
}
@mastersthesis {4082,
	title = {Landscape history and contemporary environmental drivers of microbial community structure and function},
	volume = {MS},
	year = {2010},
	school = {Virginia Tech},
	type = {masters},
	address = {Blacksburg, VA},
	abstract = {<p>Recent work in microbial ecology has focused on elucidating controls over biogeographic patterns and connecting microbial community composition to ecosystem function. My objective was to investigate the relative influences of landscape legacies and contemporary environmental factors on the distribution of soil microbial communities and their contribution to ecosystem processes across a glacial till sequence in Taylor Valley, Antarctica. Within each till unit, I sampled from dry areas and areas with visible evidence of recent surface water movement generated by seasonal melting of ephemeral snow packs and hillslope ground ice. Using T-RFLP 16S rRNA gene profiles of microbial communities, I analyzed the contribution of till and environmental factors to community similarity, and assessed the functional potential of the microbial community using extracellular enzyme activity assays. Microbial communities were influenced by geochemical differences among both tills and local environments, but especially organized by variables associated with water availability as the first axis of an NMDS ordination was strongly related to shifts in soil moisture content. CCA revealed that tills explained only 3.4\% of the variability in community similarity among sites, while geochemical variables explained 18.5\%. Extracellular enzyme activity was correlated with relevant geochemical variables reflecting the influence of nutrient limitation on microbial activity. In addition, enzyme activity was related to changes in community similarity, particularly in wet environments with a partial Mantel correlation of 0.32. These results demonstrate how landscape history and environmental conditions can shape the functional potential of a microbial community mediated through shifts in microbial community composition.</p>},
	keywords = {LTER-MCM, community similarity, extracellular enzyme activity, McMurdo Dry Valleys, microbial biogeography, soil geochemistry, T-RFLP},
	url = {http://hdl.handle.net/10919/31883},
	author = {Adam E. Altrichter},
	editor = {John E. Barrett}
}
