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• 1. [Article] Microbial Biogeochemistry of Boiling Springs Lake: a Physically Dynamic, Oligotrophic, Low-p H Geothermal Ecosystem

  Boiling Springs Lake (BSL) in Lassen Volcanic National Park, California, is North America's largest hot spring, but little is known about the physical, chemical, and biological features of the system. ...

  Citation × Citation Citation Abstract Copy Title: Microbial Biogeochemistry of Boiling Springs Lake: a Physically Dynamic, Oligotrophic, Low-p H Geothermal Ecosystem Author: Siering, Patricia Lynne, Wolfe, Gordon V., Wilson, Mark S., Yip, A. N., Carey, Cynthia M., Wardman, Colin D., Shapiro, Russell Scott, Stedman, Kenneth M., Kyle, Jennifer E., Yuan, Tong, Van Nostrand, Joy D., He, Zhili, Zhou, Jizhong Year: 2013 Boiling Springs Lake (BSL) in Lassen Volcanic National Park, California, is North America's largest hot spring, but little is known about the physical, chemical, and biological features of the system. Using a remotely operated vessel, we characterized the bathymetry and near-surface temperatures at sub-meter resolution. The majority of the 1.2 ha, pH 2.2 lake is 10 m deep and 50-52 [degrees]C, but temperatures reach 93 [degrees]C locally. We extracted DNA from water and sediments collected from warm (52 [degrees]C) and hot (73-83 [degrees]C) sites separated by 180 m. Gene clone libraries and functional gene microarray (GeoChip 3.0) were used to investigate the BSL community, and uptake of radiolabeled carbon sources was used to assess the relative importance of heterotrophic vs. autotrophic production. Microbial assemblages are similar in both sites despite the strong temperature differential, supporting observations of a dynamic, convectively mixed system. Bacteria in the Actinobacteria and Aquificales phyla are abundant in the water column, and Archaea distantly related to known taxa are abundant in sediments. The functional potential appears similar across a 5-year time span, indicating a stable community with little inter-annual variation, despite the documented seasonal temperature cycle. BSL water-derived DNA contains genes for complete C, N, and S cycles, and low hybridization to probes for N and S oxidation suggests that reductive processes dominate. Many of the detected genes for these processes were from uncultivated bacteria, suggesting novel organisms are responsible for key ecosystem services. Selection imposed by low nutrients, low pH, and high temperature appear to result in low diversity and evenness of genes for key functions involved in C, N, and S cycling. Conversely, organic degradation genes appear to be functionally redundant, and the rapid assimilation of radiolabeled organic carbon into BSL cells suggests the importance of allochthonous C fueling heterotrophic production in the BSL C cycle. Title: Microbial Biogeochemistry of Boiling Springs Lake: a Physically Dynamic, Oligotrophic, Low-p H Geothermal Ecosystem Author: Siering, Patricia Lynne, Wolfe, Gordon V., Wilson, Mark S., Yip, A. N., Carey, Cynthia M., Wardman, Colin D., Shapiro, Russell Scott, Stedman, Kenneth M., Kyle, Jennifer E., Yuan, Tong, Van Nostrand, Joy D., He, Zhili, Zhou, Jizhong Year: 2013 Boiling Springs Lake (BSL) in Lassen Volcanic National Park, California, is North America's largest hot spring, but little is known about the physical, chemical, and biological features of the system. Using a remotely operated vessel, we characterized the bathymetry and near-surface temperatures at sub-meter resolution. The majority of the 1.2 ha, pH 2.2 lake is 10 m deep and 50-52 [degrees]C, but temperatures reach 93 [degrees]C locally. We extracted DNA from water and sediments collected from warm (52 [degrees]C) and hot (73-83 [degrees]C) sites separated by 180 m. Gene clone libraries and functional gene microarray (GeoChip 3.0) were used to investigate the BSL community, and uptake of radiolabeled carbon sources was used to assess the relative importance of heterotrophic vs. autotrophic production. Microbial assemblages are similar in both sites despite the strong temperature differential, supporting observations of a dynamic, convectively mixed system. Bacteria in the Actinobacteria and Aquificales phyla are abundant in the water column, and Archaea distantly related to known taxa are abundant in sediments. The functional potential appears similar across a 5-year time span, indicating a stable community with little inter-annual variation, despite the documented seasonal temperature cycle. BSL water-derived DNA contains genes for complete C, N, and S cycles, and low hybridization to probes for N and S oxidation suggests that reductive processes dominate. Many of the detected genes for these processes were from uncultivated bacteria, suggesting novel organisms are responsible for key ecosystem services. Selection imposed by low nutrients, low pH, and high temperature appear to result in low diversity and evenness of genes for key functions involved in C, N, and S cycling. Conversely, organic degradation genes appear to be functionally redundant, and the rapid assimilation of radiolabeled organic carbon into BSL cells suggests the importance of allochthonous C fueling heterotrophic production in the BSL C cycle. Close

• 2. [Article] An examination of vegetation modeling-related issues and the variation and climate sensitivity of vegetation and hydrology in China

  xvi, 156 p. A print copy of this thesis is available through the UO Libraries. Search the library catalog for the location and call number.

  Citation × Citation Citation Abstract Copy Title: An examination of vegetation modeling-related issues and the variation and climate sensitivity of vegetation and hydrology in China Author: Tang, Guoping Year: 2009, 2008 xvi, 156 p. A print copy of this thesis is available through the UO Libraries. Search the library catalog for the location and call number. Title: An examination of vegetation modeling-related issues and the variation and climate sensitivity of vegetation and hydrology in China Author: Tang, Guoping Year: 2009, 2008 xvi, 156 p. A print copy of this thesis is available through the UO Libraries. Search the library catalog for the location and call number. Close

• 3. [Article] Microbial activity in the marine deep biosphere: progress and prospects

  This is the publisher’s final pdf. The published article is copyrighted by the author(s) and published by Frontiers Research Foundation. The published article can be found at: http://www.frontiersin.or...

  Citation × Citation Citation Abstract Copy Title: Microbial activity in the marine deep biosphere: progress and prospects Author: Kirkpatrick, John B., Sylvan, Jason B., Colwell, Frederick S., Lapham, Laura L., Glazer, Brian T., Wheat, C. Geoff, Wankel, Scott D., Mills, Heath J., Reese, Brandi Kiel, Orcutt, Beth N., Biddle, Jennifer F., LaRowe, Douglas E. This is the publisher’s final pdf. The published article is copyrighted by the author(s) and published by Frontiers Research Foundation. The published article can be found at: http://www.frontiersin.org/Microbiology. Title: Microbial activity in the marine deep biosphere: progress and prospects Author: Kirkpatrick, John B., Sylvan, Jason B., Colwell, Frederick S., Lapham, Laura L., Glazer, Brian T., Wheat, C. Geoff, Wankel, Scott D., Mills, Heath J., Reese, Brandi Kiel, Orcutt, Beth N., Biddle, Jennifer F., LaRowe, Douglas E. This is the publisher’s final pdf. The published article is copyrighted by the author(s) and published by Frontiers Research Foundation. The published article can be found at: http://www.frontiersin.org/Microbiology. Close

• 4. [Article] Snow-Patch Influence on Soil Biogeochemical Processes and Invertebrate Distribution in the McMurdo Dry Valleys, Antarctica

  The McMurdo Dry Valleys is the largest of the ice-free areas in Antarctica. Precipitation events in excess of 1 cm of snow accumulation are rare. During the winter, snow is transported by strong katabatic ...

  Citation × Citation Citation Abstract Copy Title: Snow-Patch Influence on Soil Biogeochemical Processes and Invertebrate Distribution in the McMurdo Dry Valleys, Antarctica Author: Gooseff, Michael N., Barrett, John E., Doran, Peter T., Fountain, Andrew G., Lyons, W. Berry, Parsons, Andrew N., Porazinska, Dorota L., Virginia, Ross A., Wall, Diana H. Year: 2003 The McMurdo Dry Valleys is the largest of the ice-free areas in Antarctica. Precipitation events in excess of 1 cm of snow accumulation are rare. During the winter, snow is transported by strong katabatic winds blowing from the polar plateau, and deposited into the lee of topographic features (e.g., stream channels and other topographic depressions). At the start of the austral summer (early October), as much as 10% of the valley soils may be covered by distributed snow patches. Because liquid water is the primary driver of biological, physical, and chemical processes in this polar desert, quantifying fluxes of water from snow patches is important to understanding the influence of hydrology on soil biology and nutrient cycling. During the austral summer of 1999-2000, four snow patches that had developed during the previous winter in Taylor Valley were studied. We measured snow-patch area, depth, and snow water equivalent, as well as subnivian (under snow) and nearby exposed (control) soil temperature, light intensity, soil moisture, invertebrate abundance, soil organic matter content, and 95-d labile pools of C and N. Subnivian soils differed from exposed soils being as much as 26.88 ⁰C colder than exposed soils; average soil moisture ranging from 6.9 to 13.6% compared to 0.4% in exposed soils; soil invertebrate populations exceeding 7900 individuals kg⁻¹ dry soil versus less than 1200 individuals kg⁻¹ dry soil in exposed soils; and soil invertebrate species richness values greater than 2 taxa, compared to 1.3 taxa in exposed soils. The results of this study show that these seasonal, sparse snow patches may be an important source of moisture and control habitat of soil ecosystems in this extreme environment. Title: Snow-Patch Influence on Soil Biogeochemical Processes and Invertebrate Distribution in the McMurdo Dry Valleys, Antarctica Author: Gooseff, Michael N., Barrett, John E., Doran, Peter T., Fountain, Andrew G., Lyons, W. Berry, Parsons, Andrew N., Porazinska, Dorota L., Virginia, Ross A., Wall, Diana H. Year: 2003 The McMurdo Dry Valleys is the largest of the ice-free areas in Antarctica. Precipitation events in excess of 1 cm of snow accumulation are rare. During the winter, snow is transported by strong katabatic winds blowing from the polar plateau, and deposited into the lee of topographic features (e.g., stream channels and other topographic depressions). At the start of the austral summer (early October), as much as 10% of the valley soils may be covered by distributed snow patches. Because liquid water is the primary driver of biological, physical, and chemical processes in this polar desert, quantifying fluxes of water from snow patches is important to understanding the influence of hydrology on soil biology and nutrient cycling. During the austral summer of 1999-2000, four snow patches that had developed during the previous winter in Taylor Valley were studied. We measured snow-patch area, depth, and snow water equivalent, as well as subnivian (under snow) and nearby exposed (control) soil temperature, light intensity, soil moisture, invertebrate abundance, soil organic matter content, and 95-d labile pools of C and N. Subnivian soils differed from exposed soils being as much as 26.88 ⁰C colder than exposed soils; average soil moisture ranging from 6.9 to 13.6% compared to 0.4% in exposed soils; soil invertebrate populations exceeding 7900 individuals kg⁻¹ dry soil versus less than 1200 individuals kg⁻¹ dry soil in exposed soils; and soil invertebrate species richness values greater than 2 taxa, compared to 1.3 taxa in exposed soils. The results of this study show that these seasonal, sparse snow patches may be an important source of moisture and control habitat of soil ecosystems in this extreme environment. Close