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Full-Text Articles in Physical Sciences and Mathematics

Higher Temperatures Have Contrasting Effects On Different Components Of Forage Quality For Caribou In Northern Alaska, Heidi Becker Jan 2020

Higher Temperatures Have Contrasting Effects On Different Components Of Forage Quality For Caribou In Northern Alaska, Heidi Becker

Electronic Theses and Dissertations

Rising temperatures in the Arctic may affect vegetation, which in turn can affect herbivores, such as caribou, that rely on these plants for forage. Several plant traits contribute to forage quality, including digestibility, nitrogen content, and antiherbivory secondary compounds, but the effect of temperature on these traits individually and combined is unclear. I conducted a three-component study on the effect of higher temperatures on the forage quality of graminoids, deciduous shrubs, and evergreen dwarf shrubs on the North Slope of Alaska. The components included: 1) short and long-term experimental warming, 2) natural temperature variation between south and north-facing slopes, and …


Winter Snow Depth In Arctic Alaska Results In Complex Changes In Caribou Forage Quality, Jessica C. Richert Jan 2019

Winter Snow Depth In Arctic Alaska Results In Complex Changes In Caribou Forage Quality, Jessica C. Richert

Electronic Theses and Dissertations

Caribou (Rangifer tarandus) rely on the short growing season for much of their annual nutrition, making them susceptible to even small changes in forage quantity and quality. Body condition in the summer and fall is linked to winter survival rates and fecundity in cows, critical factors in the robustness of caribou populations. Due to a warmer, wetter climate, snowfall is predicted to increase over Alaska’s North Slope in the next several decades. Deeper snow results in higher soil temperatures, allowing microbial mineralization of nitrogen to continue throughout the winter and increasing the availability of nitrogen for plants in spring and …


Determination Of Volcanic Impact On Perchlorate Using Polar Ice Cores, Alex Georgiev, Collin Livingston, Cody Ward Jan 2016

Determination Of Volcanic Impact On Perchlorate Using Polar Ice Cores, Alex Georgiev, Collin Livingston, Cody Ward

The Journal of Undergraduate Research

Arctic (Greenland) ice core samples covering the time period of 1638-1646 were analyzed for perchlorate and sulfate concentrations. The sulfate data show a signal corresponding to the 1640 eruption of the Komaga-Take volcano in Japan. Perchlorate concentrations show a significant increase at the time of the Komaga-Take eruption. It is concluded that a positive correlation likely exists between stratospheric volcanic eruptions and perchlorate concentration in the environment. When a volcano has enough explosive force to inject substances into the stratosphere, some of the substances, such as sulfate, can remain in the stratosphere for months and spread all over the global …