Life Sciences Commons^™

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 …

Effect Of Foliage And Root Carbon Quantity, Quality, And Fluxes On Soil Organic Carbon Stabilization In Montane Aspen And Conifer Stands In Utah, Antra Boča

All Graduate Theses and Dissertations, Spring 1920 to Summer 2023

Soil organic carbon (SOC) positively affects many soil properties (e.g., fertility and water holding capacity), and the amount of carbon (C) in soil exceeds the amount in the atmosphere by about three times. Forest soils store as much C as is found in trees. Tree species differ in their effect on SOC pools. Quaking aspen forests in the Western US often store more stable SOC in the mineral soil than nearby conifers. During the last decades a decline in aspen cover, often followed by conifer encroachment, has been documented. A shift from aspen to conifer overstories may negatively affect the …

Comparison Of Water Dynamics In Aspen And Conifer: Implications For Ecology Water Yield Augmentation, Eric Martin Lamalfa

All Graduate Theses and Dissertations, Spring 1920 to Summer 2023

Differences in water dynamics between deciduous aspen (Populus tremuloides) and co-occurring evergreen conifer species in the Northern Rocky Mountains result from complex physical and biological interactions. A comprehensive evaluation of individual water transfer mechanisms was used to elucidate the relative importance of several components of the hydro logic cycles of aspen and conifer, and determine which water transfer mechanisms have potential to cause differences in net water yield.

Adjacent aspen and conifer stands were monitored to determine snow accumulation and ablation (snow survey), soil moisture recharge (capacitance probes), snowpack sublimation (sublimation pan), transpiration period (thermal dissipation probes), and …

Restoration Of Aspen In Different Stages Of Mortality In Southern Utah, Seth Ray Ohms

All Graduate Theses and Dissertations, Spring 1920 to Summer 2023

Aspen clones of an aspen-dominated community in Southwestern Utah are declining, some having experienced high mortality coupled with in sufficient regeneration. The objectives of this study were to (I) determine if decadent, non-regenerating mature aspen stands could be regenerated through disturbance of the 111 auxin/cytokinin hormone relationship by clearcutting; (2) determine the extent of ungulate use of regenerating aspen ramets. Clearcuts were made in late summer of 2001 in 10 different clones that exhibited various levels of decline on a continuum from relatively healthy to extremely deteriorated. Nested wildlife/livestock exclosures were constructed in each clearcut plot, as well as in …