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Physical Sciences and Mathematics Commons

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Full-Text Articles in Physical Sciences and Mathematics

Impacts Of Long-Term Precipitation Manipulation On Hydraulic Architecture, Xylem Function, And Canopy Status In A Piñon-Juniper Woodland, Patrick J. Hudson Dec 2016

Impacts Of Long-Term Precipitation Manipulation On Hydraulic Architecture, Xylem Function, And Canopy Status In A Piñon-Juniper Woodland, Patrick J. Hudson

Biology ETDs

The Southwestern US is predicted to become hotter and drier, as global climate change forces increasing temperatures and variability in timing and size of precipitation inputs. Drought stress has become more frequent in recent decades, and resulted in massive forest mortality in piñon-juniper woodlands. During recent severe droughts (2000-2003, 2009-2012), piñon pine (Pinus edulis Englem.) suffered disproportionately high mortality compared to co-occurring one-seed juniper (Juniperus monosperma [Engelm.] Sarg.). A large-scale precipitation manipulation experiment was established in a piñon-juniper woodland in central New Mexico to test hypotheses regarding tree survival and mortality with respect to altered water regimes. Our …


Sea Surface Temperature Rises Shift Migration Patterns Due To Ecosystem Changes, Alexia Skrbic, Hesham El-Askary Dec 2016

Sea Surface Temperature Rises Shift Migration Patterns Due To Ecosystem Changes, Alexia Skrbic, Hesham El-Askary

Student Scholar Symposium Abstracts and Posters

The continuing climate change is negatively impacting ecosystems, specifically oceans which are declining and food webs are being altered by the increase of greenhouse gases. The increase of the carbon dioxide and other greenhouse gases is increasing sea surface temperature of the world’s oceans. Certain organisms lower on the food chain like phytoplankton and zooplankton are directly affected by the warming which alters how they process nutrients and their productivity. The limited amount of these primary producers in the oceans and specifically the location they inhabit directly affects all the organisms above them on the food chain. Several marine animals …


Linking In-Situ Data With Remote Sensing To Analyze Tropical Glacier Stability And Retreat In The Cordillera Blanca, Peru, Chandler H. Santos Jul 2016

Linking In-Situ Data With Remote Sensing To Analyze Tropical Glacier Stability And Retreat In The Cordillera Blanca, Peru, Chandler H. Santos

Masters Theses & Specialist Projects

Glaciers are a major source of freshwater around the world, but they are melting at an increased rate due to atmospheric warming resulting from anthropogenic climate change. In addition to temperature increases, light-absorbing particulates on glaciers also are contributing to glacial melt. This research examines how black carbon, released into the air through partial combustion of biofuels, is affecting the surface albedo of glaciers. I also delineate possible sources of black carbon in the Cordillera Blanca region of Peru. Ground data were collected each year from 2011 to 2013 during the local dry season. Effective black carbon (eBC) values were …


Assessing Drought Vulnerability Using A Socioecological Framework, Joel R. Brown, Doug Kluck, Chad Mcnutt, Michael J. Hayes Jan 2016

Assessing Drought Vulnerability Using A Socioecological Framework, Joel R. Brown, Doug Kluck, Chad Mcnutt, Michael J. Hayes

Drought Mitigation Center: Faculty Publications

Drought is a persistent problem on rangelands and adjusting management to respond appropriately is critical to both preserving natural resources and to maintaining financial viability. • We explore the value of using a structured assessment approach to determining both social and ecological vulnerability. • This approach allows for the identification of vulnerable ecosystems and business operations at regional and local scales as a basis for developing effective policies and programs.


Methane Emissions As Energy Reservoir: Context, Scope, Causes And Mitigation Strategies, Xiaoli Chai, David J. Tonjes, Devinder Mahajan Jan 2016

Methane Emissions As Energy Reservoir: Context, Scope, Causes And Mitigation Strategies, Xiaoli Chai, David J. Tonjes, Devinder Mahajan

Technology & Society Faculty Publications

Methane (CH4) is now considered a bridge fuel between present fossil (carbon) economy and desired renewables and this energy molecule is projected to play an important role in the global energy mix well beyond 2035. The atmospheric warming potential of CH4 is 28-36 times, when averaged over a 100-year period, that of carbon dioxide (CO2) and this necessitates a close scrutiny of global CH4 emissions inventory. As the second most abundant greenhouse gas (GHG), the annual global CH4 emissions were 645 million metric tons (MMT), accounting for 14.3% of the global anthropogenic GHG emissions. Of this, five key anthropogenic sources: …


Body Size Distributions Signal A Regime Shift In A Lake Ecosystem, Trisha L. Spanbauer, Craig R. Allen, David G. Angeler, Tarsha Eason, Sherilyn C. Fritz, Ahjond S. Garmestani, Kirsty L. Nash, Jeffery R. Stone, Craig A. Stow, Shana M. Sundstrom Jan 2016

Body Size Distributions Signal A Regime Shift In A Lake Ecosystem, Trisha L. Spanbauer, Craig R. Allen, David G. Angeler, Tarsha Eason, Sherilyn C. Fritz, Ahjond S. Garmestani, Kirsty L. Nash, Jeffery R. Stone, Craig A. Stow, Shana M. Sundstrom

Nebraska Cooperative Fish and Wildlife Research Unit: Staff Publications

Communities of organisms, from mammals to microorganisms, have discontinuous distributions of body size. This pattern of size structuring is a conservative trait of community organization and is a product of processes that occur at multiple spatial and temporal scales. In this study, we assessed whether body size patterns serve as an indicator of a threshold between alternative regimes. Over the past 7000 years, the biological communities of Foy Lake (Montana, USA) have undergone a major regime shift owing to climate change. We used a palaeoecological record of diatom communities to estimate diatom sizes, and then analysed the discontinuous distribution of …


Until We Meet Again, Richard Snow, Mary Snow Jan 2016

Until We Meet Again, Richard Snow, Mary Snow

Publications

As long ago as 1896, Svanti Arrenius conducted a scientific analysis of the relationship between carbon dioxide (CO2) and atmospheric temperatures. Several decades later, GS Callender collected and compiled temperature data from around the world and found there had been an increase in global temperatures. He hypothesized that the rising temperatures were resulting from increasing levels of CO2. These early studies piqued the interest of Gilbert Plass in the mid-20th century who endeavored to determine how CO2 affects temperature. In his effort to determine the possible effects that higher levels of CO2 in the atmosphere were having on the energy …