Search Results - "SICKMAN, JAMES O"

Isogeochemical Characterization of Mountain System Recharge Processes in the Sierra Nevada, California by Armengol, Sandra, Ajami, Hoori, Acero Triana, Juan S., O. Sickman, James, Ortega, Lucia

“…Mountain System Recharge processes are significant natural recharge pathways in many arid and semi‐arid mountainous regions. However, Mountain System Recharge…”
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Aridity and plant uptake interact to make dryland soils hotspots for nitric oxide (NO) emissions by Homyak, Peter M., Blankinship, Joseph C., Marchus, Kenneth, Lucero, Delores M., Sickman, James O., Schimel, Joshua P.

“…Nitric oxide (NO) is an important trace gas and regulator of atmospheric photochemistry. Theory suggests moist soils optimize NO emissions, whereas wet or dry…”
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effect of permafrost thaw on old carbon release and net carbon exchange from tundra by Schuur, Edward A.G, Vogel, Jason G, Crummer, Kathryn G, Lee, Hanna, Sickman, James O, Osterkamp, T.E

“…Permafrost soils in boreal and Arctic ecosystems store almost twice as much carbon as is currently present in the atmosphere. Permafrost thaw and the microbial…”
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Acidity and organic matter promote abiotic nitric oxide production in drying soils by Homyak, Peter M., Kamiyama, Matthew, Sickman, James O., Schimel, Joshua P.

“…Soils are an important source of NO, particularly in dry lands because of trade‐offs that develop between biotic and abiotic NO‐producing processes when soils…”
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Climate warming response of mountain lakes affected by variations in snow by Sadro, Steven, Melack, John M., Sickman, James O., Skeen, Kevin

“…Our objectives were to determine how temperatures in mountain lakes respond to changes in climate and to characterize how their responses are mediated by…”
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Assessing Nitrogen-Saturation in a Seasonally Dry Chaparral Watershed: Limitations of Traditional Indicators of N-Saturation by Homyak, Peter M, Sickman, James O, Miller, Amy E, Melack, John M, Meixner, Thomas, Schimel, Joshua P

“…To evaluate nitrogen (N) saturation in xeric environments, we measured hydrologic N losses, soil N pools, and microbial processes, and developed an N-budget…”
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Ecological Effects of Nitrogen Deposition in the Western United States by FENN, MARK E, BARON, JILL S, ALLEN, EDITH B, RUETH, HEATHER M, NYDICK, KOREN R, GEISER, LINDA, BOWMAN, WILLIAM D, SICKMAN, JAMES O, MEIXNER, THOMAS, JOHNSON, DALE W, NEITLICH, PETER

“…In the western United States vast acreages of land are exposed to low levels of atmospheric nitrogen (N) deposition, with interspersed hotspots of elevated N…”
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Nitrogen assessment points: development and application to high‐elevation lakes in the Sierra Nevada, California by Heard, Andrea M., Sickman, James O.

“…Abstract Increased nitrogen (N) inputs to oligotrophic high‐elevation lakes are contributing to long‐term eutrophication, changes in nutrient cycles, and…”
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Effects of Climate Variability on Snowmelt and Implications for Organic Matter in a High‐Elevation Lake by Sadro, Steven, Sickman, James O., Melack, John M., Skeen, Kevin

“…Few coupled lake‐watershed studies examine long‐term effects of climate on the ecosystem function of lakes in a hydrological context. We use 32 years of…”
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Evidence for Nutrient Enrichment of High-Elevation Lakes in the Sierra Nevada, California by Sickman, James O., Melack, John M., Clow, David W.

“…Long-term measurements (1983-2001) of nutrients and seston in Emerald Lake (Sierra Nevada, California) have revealed ecologically significant patterns…”
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Event-Response Ellipses: A Method to Quantify and Compare the Role of Dynamic Storage at the Catchment Scale in Snowmelt-Dominated Systems by Driscoll, Jessica, Meixner, Thomas, Molotch, Noah, Ferre, Ty, Williams, Mark, Sickman, James

“…A method for quantifying the role of dynamic storage as a physical buffer between snowmelt and streamflow at the catchment scale is introduced in this paper…”
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Linking transit times to catchment sensitivity to atmospheric deposition of acidity and nitrogen in mountains of the western United States by Clow, David W., Mast, M. Alisa, Sickman, James O.

“…Transit times are hypothesized to influence catchment sensitivity to atmospheric deposition of acidity and nitrogen (N) because they help determine the amount…”
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Rapid nitrate reduction produces pulsed NO and N2O emissions following wetting of dryland soils by Krichels, Alexander H., Homyak, Peter M., Aronson, Emma L., Sickman, James O., Botthoff, Jon, Shulman, Hannah, Piper, Stephanie, Andrews, Holly M., Jenerette, G. Darrel

“…Soil drying and wetting cycles can produce pulses of nitric oxide (NO) and nitrous oxide (N 2 O) emissions with substantial effects on both regional air…”
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Modeling of Soil Organic Carbon Fractions Using Visible-Near-Infrared Spectroscopy by Vasques, Gustavo M, Grunwald, Sabine, Sickman, James O

“…There is a pressing need for rapid and cost-effective tools to estimate soil C across larger landscapes. Visible-near-infrared diffuse reflectance spectroscopy…”
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Biogeochemical legacy of prescribed fire in a giant sequoia–mixed conifer forest: A 16-year record of watershed balances by Engle, Diana L., Sickman, James O., Moore, Claudette M., Esperanza, Annie M., Melack, John M., Keeley, Jon E.

“…The effects of prescription burning on watershed balances of major ions in mixed conifer forest were examined in a 16‐year paired catchment study in Sequoia…”
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Regional Analysis of Inorganic Nitrogen Yield and Retention in High-Elevation Ecosystems of the Sierra Nevada and Rocky Mountains by Sickman, James O., Melack, John M., Stoddard, John L.

“…Yields and retention of dissolved inorganic nitrogen (DIN: NO3-+NH4+) and nitrate concentrations in surface runoff are summarized for 28 high elevation…”
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Quantifying atmospheric N deposition in dryland ecosystems: A test of the Integrated Total Nitrogen Input (ITNI) method by Sickman, James O., James, Amanda E., Fenn, Mark E., Bytnerowicz, Andrzej, Lucero, Delores M., Homyak, Peter M.

“…Estimating nitrogen (N) deposition to terrestrial ecosystems is complicated by the multiple forms and routes of N loading from the atmosphere. We used the…”
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Influence of soil moisture on the seasonality of nitric oxide emissions from chaparral soils, Sierra Nevada, California, USA by Homyak, Peter M., Sickman, James O.

“…Soil nitric oxide (NO) emissions are variable in both space and time, and are important pathways for N loss in seasonally dry ecosystems that undergo abrupt…”
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Isotope stratigraphy: Insights on paleoclimate and formation of nitrate deposits in the Atacama Desert, Chile by Melchiorre, Erik B., Sickman, James O., Talyn, Becky C., Noblet, James

“…Arid environment nitrate deposits are economically important and analogous to Martian environments, but their formation is poorly understood. Detailed N, O,…”
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Interannual variability of snowmelt in the Sierra Nevada and Rocky Mountains, United States: Examples from two alpine watersheds by Jepsen, Steven M., Molotch, Noah P., Williams, Mark W., Rittger, Karl E., Sickman, James O.

“…The distribution of snow and the energy flux components of snowmelt are intrinsic characteristics of the alpine water cycle controlling the location of source…”
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