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Full-Text Articles in Life Sciences
Environmental Factors Associated With Triploid Aspen Occurrence In Intermountain West Landscapes, James A. Walton
Environmental Factors Associated With Triploid Aspen Occurrence In Intermountain West Landscapes, James A. Walton
All Graduate Theses and Dissertations, Fall 2023 to Present
Polyploidy is common among plants and can contribute to physiological and morphological differences, altering how plants respond to environmental changes, promoting genetic diversification and even species radiation. Quaking aspen (Populus tremuloides), a keystone species associated with high plant and animal diversity is frequently found in mixed diploid/triploid populations in the Intermountain West. Triploid aspen carries an extra chromosomal copy, whereas the diploid type contains two chromosomal copies. High mortality rates and widespread population declines in aspen are of increasing concern in the Intermountain West, and often ascribed to changing climates and drought stress events. The goal of this …
The Influence Of Aspen Chemistry And The Nutritional Context On Aspen Herbivory, Kristen Y. Heroy
The Influence Of Aspen Chemistry And The Nutritional Context On Aspen Herbivory, Kristen Y. Heroy
All Graduate Theses and Dissertations, Spring 1920 to Summer 2023
Consumption of aspen by herbivores is one major force causing aspen decline in North America. In this Dissertation, I aimed to determine why herbivores prefer browsing on certain aspen stands over others, and why they prefer consuming aspen that contains chemical defenses over understory forages like grasses, forbs, and shrubs. I explored the influence of nutrients and chemical defenses within aspen on aspen intake and preference by lambs in pen experiments. I also explored drivers of aspen preference on the landscape by looking at relationships between aspen herbivory, indicators of aspen health, amount of nutrients available in the understory, and …
Aspen Regeneration And Response To Fire In The Intermountain West, Kelly J. Mccloskey
Aspen Regeneration And Response To Fire In The Intermountain West, Kelly J. Mccloskey
All Graduate Theses and Dissertations, Spring 1920 to Summer 2023
The history of Populus tremuloides regeneration in the Intermountain West, particularly western Wyoming, is one of prolific vegetative reproduction following wildland fire. The reproductive physiology of aspen and its disturbance-response characteristics are explored through a review of previous studies. The combination of fire suppression and increased herbivory on aspen by wild and domestic ungulates is likely facilitating conifer invasion of areas historically dominated by aspen as has been observed in parts of Wyoming, Utah, and Colorado over the past 100 years. A case study of the regenerative response of aspen to wildland fire in western Wyoming demonstrates how physiology, life …