Life Sciences Commons^™

The Role Of Fire In Aspen Ecology And Restoration, Douglas J. Shinneman, Kevin D. Krasnow, Susan K. Mcilroy

Aspen Bibliography

Quaking aspen is generally considered to be a fire-adapted species because it regenerates prolifically after fire, and it can be replaced by more shade-tolerant tree species in the absence of fire. As early-successional aspen stands transition to greater conifer-dominance, they become increasingly fire prone, until fire returns, and aspen again temporarily dominate. While this disturbance-succession cycle is critical to the persistence of aspen on many landscapes, some aspen stands persist on the landscape without fire. The complex role of fire is an important consideration for developing conservation and restoration strategies intended to sustain aspen.

Variation In Trembling Aspen And White Spruce Wood Quality Grown In Mixed And Single Species Stands In The Boreal Mixedwood Forest, Francis De Araujo, James F. Hart, Shawn D. Mansfield

Aspen Bibliography

The Canadian boreal forest is largely represented by mixed wood forests of white spruce (Picea glauca (Moench) Voss) and trembling aspen (Populus tremuloides Michx). In this study, a total of 300 trees originating from three sites composed of trembling aspen and white spruce with varying compositions were investigated for wood quality traits: one site was composed mainly of aspen, one mainly of spruce and a third was a mixed site. Four wood quality traits were examined: wood density, microfibril angle (MFA), fibre characteristics, and cell wall chemistry. Social classes were also determined for each site in an attempt …

Development Of Genetic Goat And Hamster Models Of Atrial Fibrillation And Long Qt Syndrome; And Genetic Hamster Models Of Middle East Respiratory Syndrome, Dane A. Rasmussen

All Graduate Theses and Dissertations, Spring 1920 to Summer 2023

Atrial fibrillation (AF) and long QT syndrome (LQTS) are potentially lethal heart rhythm disorders that can be caused by mutations in the potassium channel gene KCNQ1. Middle East Respiratory Syndrome (MERS) is a viral infection with the potential to replicate the devastating effects of the SARS outbreak in 2003. All three of these diseases are in need of genetic animal models.

To address these needs, my thesis project focused on the development of genetic goat and hamster models of AF and LQTS, and genetic hamster models of MERS. Because of the goat’s similar organ size/physiology and the hamster’s similar lipid …

Annotation Tools For Multivariate Gene Set Testing Of Non-Model Organisms, Russell K. Banks

All Graduate Theses and Dissertations, Spring 1920 to Summer 2023

Microarray chip technology enables researchers to obtain measures of gene activity for essentially all genes in an organism. After grouping genes into biologically meaningful sets, researchers employ certain statistical tests to identify which gene sets (biological processes) show different levels of activity across different treatment groups. The idea is to identify which biological processes are significantly affected by a certain treatment/condition in a given organism.

Non-model organisms (such as sheep) are not widely studied so gene set membership information is not always readily accessible. This thesis work utilizes two microarray studies involving sheep to provide researchers with working examples of …

Building Resilience Into Quaking Aspen Management, Paul C. Rogers

Aspen Bibliography

Throughout the 20^th century, forest scientists and land managers were guided by principles of succession with regard to aspen forests. The historical model depicted aspen as a "pioneer species" that colonizes a site following disturbance and is eventually overtopped by conifers. Aspen systems are more diverse, however, than previously described. Not only are there distinctive seral and stable aspen, but variations within these types require appropriate management considerations (Rogers et al. 2014). We recommend a strategic approach to aspen resilience that builds upon traditional aspen ecology and incorporates knowledge of varying aspen functional types, effective monitoring, historical disturbance ecology, …

Managing Ungulate Browsing For Sustainable Aspen, Samuel B. St. Clair, Paul C. Rogers, Michael R. Kuhns

Aspen Bibliography

In montane forests of the Intermountain West composition and function are often defined by what happens with quaking aspen. Aspen is a pioneer species that regenerates quickly following disturbance and then establishes ecological conditions under which the rest of the biological community develops. Quaking aspen forests have high biodiversity and provide ideal habitat for many animals. Aspen regeneration from root sprouts is highly palatable to wildlife and livestock. When browsing becomes chronic it leads to regeneration failure and eventual loss of aspen forests and associated species. Ironically, this can result in habitat and forage loss for wildlife and livestock. Here …

Stand Dynamics, Humus Type And Water Balance Explain Aspen Long Term Productivity Across Canada, Kenneth A. Anyomi, Francois Lorenzetti, Yves Bergeron, Alain Leduc

Aspen Bibliography

This study examined the relative importance of soil, stand development and climate hypotheses in driving productivity for a species that is widely distributed in North America. Inventory plots, 3548 of such, either dominated by aspen or made up of species mixture of which aspen occurs in dominant canopy position were sampled along a longitudinal gradient from Quebec to British Columbia. Site index (SI), was used as a measure of productivity, and soil, climate and stand attributes were correlated with site index in order to determine their effects on productivity. Results show a decline in productivity with high moisture deficit. Soil …

Year-End Report On Rac Project Entitled "Propagating Aspen Clones: Survival In The 21st Century", Ralph Baierlein

Aspen Bibliography

No abstract provided.

Altered Fire Regimes And The Persistence Of Quaking Aspen In The Rocky Mountains: A Literature Review, Aaron Rosenblum

Aspen Bibliography

The persistence of quaking aspen (Populus tremuloides Michx.) is of significant importance to land managers in the Rocky Mountain region. Fire suppression in the past century has been implicated as a mechanism influencing aspen population dynamics, as aspen are generally considered an early seral disturbance adapted species. The heterogeneity of aspen community assemblages and fire regimes makes it difficult to discern what the result of fire suppression has been at large spatial and temporal scales. Decision makers should investigate the questions at hand at the stand level in their study location to best determine the mechanisms at play, as well …

Long-Term Vegetation Change In Utah's Henry Mountains: A Study In Repeat Photography, Charles E. Kay

Aspen Bibliography

An extensive search was conducted of archival and other sources to locate as many historical photographs as possible for the Henry Mountains in south-central Utah. Those images were then taken into the field, the original camera stations relocated, and modern pictures made of the historical scenes to evaluate long-term vegetation change and land management activities. In all, 626 repeat photo sets were compiled—608 by the author and 18 by Earl Hindley. This book includes 126 photo sets that were representative of the areas studied.

Quaking Aspen At The Residential-Wildland Interface: Elk Herbivory Hinders Forest Conservation., Paul C. Rogers, Allison Jones, James Catlin, James Shuler, Arthur Morris, Michael R. Kuhns

Aspen Bibliography

T: Quaking aspen (Populus tremuloides) forests are experiencing numerous impediments across North America. In the West, recent drought, fire suppression, insects, diseases, climate trends, inappropriate management, and ungulate herbivory are impacting these high biodiversity forests. Additionally, ecological tension zones are sometimes created at residential-wildland interfaces with divergent management directives. For example, private conservation reserves bordering public land may be degraded from browsing where game species find refuge from hunting and plentiful forage. We examined putative herbivore impacts to nearly pure aspen forests at Wolf Creek Ranch (WCR), a sparsely developed residential landscape in northern Utah. Forty-three one-hectare monitoring …

Regeneration Dynamics Of White Spruce, Trembling Aspen, And Balsam Poplar In Response To Disturbance, Climatic, And Edaphic Factors In The Cold, Dry Boreal Forests Of The Southwest Yukon, Canada, Shyam K. Paudel, Craig R. Nitschke, Suzanne W. Simard, John L. Innes

Aspen Bibliography

The southwestern region of the Yukon Territory of Canada has experienced an unprecedented spruce bark beetle outbreak (Dendroctonus rufipennis) and an increase in the frequency of forest fires that extend beyond historical trends and that have caused significant impacts on forest structure and composition. A Strategic Forest Management Plan (SFMP) for the Champagne and Aishihik Traditional Territory located in the southwest Yukon was implemented in 2004 in response to the spruce bark beetle (D. rufipennis) infestation and increased fire risk. The plan has recommended salvage harvesting of beetle-killed stands as a strategy to facilitate the development …