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Full-Text Articles in Life Sciences
Fire Severity And Size Alter Quaking Aspen (Populus Tremuloides) Regeneration And Defense Against Ungulate Herbivory, Ho Yi Wan
Theses and Dissertations
Human activities and rapid global climate change are altering fire regimes with potential threat to the stability of aspen ecosystems in North America. Aspen is an early successional species that plays an important role in post-fire forest reestablishment, but chronic browsing on juvenile aspen by large ungulate herbivores after fire can be detrimental and lead to regeneration failure. Although larger and more severe fires are expected to become more prominent, whether and how this may influence aspen and ungulate communities remains unclear. The objective of this research was to examine how the relationship between aspen and ungulate communities might be …
Plant-Soil Feedbacks And Subalpine Fir Facilitation In Aspen-Conifer Forests, Joshua R. Buck
Plant-Soil Feedbacks And Subalpine Fir Facilitation In Aspen-Conifer Forests, Joshua R. Buck
Theses and Dissertations
This thesis includes two studies. The first study examined changes in soil characteristics as a result of prolonged conifer dominance in successional aspen-conifer forests. Changing disturbance patterns in aspen-conifer forests appear to be altering successional dynamics that favors conifer expansion in aspen forests. The primary objective of this paper was to identify how increasing conifer dominance that develops in later successional stages alters forest soil characteristics. Soil measurements were collected along a stand composition gradient: aspen dominated, aspen-conifer mix, conifer dominated and open meadow, which includes the range of conditions that exists through the stages of secondary succession in aspen-conifer …
Variable Palatability Of Quaking Aspen For Large Ungulate Herbivores, Patrice Alexa Nielson
Variable Palatability Of Quaking Aspen For Large Ungulate Herbivores, Patrice Alexa Nielson
Theses and Dissertations
Aspen is a key resource in the Rocky Mountain Region for wildlife forage and habitat, lumber products, scenery, and plays important roles in fire ecology and hydrological processes. There is evidence of aspen decline over much of the Intermountain West for approximately 100 years. In Dixie and Fishlake National Forests, UT, aspen distribution has decreased by nearly half. Causes of this decline are not well understood, although wildlife browsing by ungulates has been implicated as playing a major role. The objective of this research was to examine what soil or plant factors might be involved in wildlife browse choice in …
Developmental Contributions To Variation In Aspen Clones And The Influence Of Pre-Fire Succession Status On Aspen Regeneration Success, Eric A. Smith
Developmental Contributions To Variation In Aspen Clones And The Influence Of Pre-Fire Succession Status On Aspen Regeneration Success, Eric A. Smith
Theses and Dissertations
This thesis includes two studies: The first examined developmental changes that take place in the physiology of aspen (Populus tremuloides Michx.) and to characterize developmental influences on patterns of phenotypic trait variation among different aged ramets within the aspen clones. We surveyed eight clones, each with 8 distinct age classes ranging from 1 to 170 yrs in age. Using regression analysis we examined the relationships between ramet age and expression of functional phenotypes. Eight of the phenotypic traits demonstrated a non-linear relationship in which large changes in phenotype occurred in the early stages of ramet development and stabilized thereafter. …