Life Sciences Commons^™

European Aspen With High Compared To Low Constitutive Tannin Defenses Grow Taller In Response To Anthropogenic Nitrogen Enrichment, Franziska Bandau, Benedicte Riber Albrectsen, Kathryn M. Robinson, Michael J. Gundale

Aspen Bibliography

Boreal forests receive nitrogen-(N)-enrichment via atmospheric deposition and industrial fertilization. While it is known that N-enrichment can intensify interactions with natural antagonists, it remains poorly understood how genetic variability in plant defense chemistry can affect biotic interactions and height growth in N-enriched environments. We grew replicates of five low- and high-tannin Populus tremula genotypes, respectively, under three N-treatments (ambient, 15, and 150 kg N ha−1 yr−1). We assessed shoot blight occurrence (i.e. symptoms caused by Venturia fungi) during four growing seasons, and tree height growth during the same period. Damage by Venturia spp. increased with N-addition during all years, likely …

Genetic Parameters Of Growth And Adaptive Traits In Aspen (Populus Tremuloides): Implications For Tree Breeding In A Warming World, Chen Ding, Andreas Hamann, Rong-Cai Yang, Jean S. Brouard

Aspen Bibliography

Aspen (Populus tremuloides Michx) is a widespread commercial forest tree of high economic importance in western Canada and has been subject to tree improvement efforts over the past two decades. Such improvement programs rely on accurate estimates of the genetic gain in growth traits and correlated response in adaptive traits that are important for forest health. Here, we estimated genetic parameters in 10 progeny trials containing >30,000 trees with pedigree structures based on a partial factorial mating design that includes 60 half-sibs, 100 full-sib families and 1,400 clonally replicated genotypes. Estimated narrow-sense and broad-sense heritabilities were low for height …

Activated Carbon Decreases Invasive Plant Growth By Mediating Plant-Microbe Interactions, Nicole E. Nolan

All Graduate Theses and Dissertations, Spring 1920 to Summer 2023

To restore lands invaded by dense, non-native vegetation, it may be necessary to develop targeted restoration tools than can remove the mechanism used by these non-native species as a competitive advantage. Activated carbon (AC) is one such tool, with the ability to disrupt the mechanisms of plant to plant communication (allelopathy) and positive plant to microbe communication commonly used by non-native species. Previous studies have shown the success of high concentrations, 1000g/m², of AC in native plant community restoration on a small scale. Here, our goals are twofold: first, to test AC effectiveness in restoring desirable plant communities …

Comparative Ecology Of Narrowly Sympatric Horned Lizards Under Variable Climatic Conditions, Kevin V. Young

All Graduate Theses and Dissertations, Spring 1920 to Summer 2023

We studied the Flat-tailed Horned Lizard, Phrynosoma mcallii, and the Sonoran Horned Lizard, P. goodei, in an area of narrow sympatry near Yuma, Arizona, and found they overlapped broadly in use of available food resources, body size, and growth rates. We compared diet (Chapter 2), growth and reproduction (Chapter 3), and survivorship (Chapter 4) of P. mcallii and P. goodei during two years of drought followed by a year of higher-than-average rainfall. We predicted that P. mcallii would be more tolerant of drought conditions than its congener, since P. mcalliiis found only in an extremely arid region while …

Growth And Water Relations Of Native Wheatgrass Populations, Brian P. Bell

All Graduate Theses and Dissertations, Spring 1920 to Summer 2023

Screening populations for development into released plant materials can be done inexpensively and in a timely manner. A common approach has been to quantify the amount of shoot dry mass produced as a surrogate for competitiveness. Besides dry mass production , other morphological characteristics have been employed , but physiological parameters have received less emphasis. Dry mass production may be an important characteristic, but identifying the traits responsible can be just as imperative . Populations with greater drought tolerance may be less impacted by competition for water from weeds, which could lead to greater establishment of desirable grasses on disturbed …

Examination Of The Ecological Differences Between Two Closely Related Endemic Whitefish In Relation To Growth Conditions And Predation Risk, Benjamen M. Kennedy

All Graduate Theses and Dissertations, Spring 1920 to Summer 2023

Benthic Bear Lake whitefish (Prosopium abyssicola) and Bonneville whitefish (P. spilontus) are closely related, yet the extent of ecological separation remains poorly understood. We described their spring and summer distribution and diet in Bear Lake and examined how these were related to environmental growth conditions, and predation risk. In spring and summer, Bonneville whitefish dominated shallower depths (5-30 m), whereas Bear Lake whitefish dominated deeper depths (45-55 m). At intermediate depths (35-40 m), low numbers of both species occurred. Bonneville whitefish ate mostly Chironomidae, whereas Bear Lake whitefish ate mostly Ostracoda. Habitats occupied by Bonneville whitefish …

Alternative Future Growth Scenarios For Conserving Open Space Along Utah's Wasatch Front: A Case Study For The Mountain Land Association Of Governments, Richard E. Toth

All Graduate Plan B and other Reports, Spring 1920 to Spring 2023

Over the past 20 years, rapid suburban and second-home development along Utah's Wasatch Front has threatened to irreversibly alter the region 's character and quality of life. This rapid development has raised concern among federal, state, county and community leaders with respect to the protection of surface and subsurface water; public health, safety and welfare; public services and infrastructure, and open space. The major areas being developed include the valley edges and bottom lands, riparian zones, agricultural lands and bench areas. Since most of these areas are under private ownership, they are highly vulnerable to an array of development activities.

Stratospheric Ozone Reduction, Solar Uv-B Radiation And Terrestrial Ecosystems, Martyn M. Caldwell, Stephan D. Flint

Green Canyon Environmental Research Area, Logan Utah

Stratospheric ozone reduction is occurring and will continue to increase in magnitude into the next century. Yet, the consequences for terrestrial ecosystems of the increased solar W-B (280-320 nm) radiation resulting from total column ozone reduction are not understood. Based on studies of higher plant response to UV-B, several possible consequences for ecosystems include decreased primary production, altered plant species composition, and altered secondary chemistry with implications for herbivory, litter decomposition and biogeochemical cycles. However, like the assessment of increased atmospheric CO2, extrapolation from studies with isolated plants to ecosystem function is very tenuous at best. Very few UV-B studies …

Growth And Water Relations Of Mountain Big Sagebrush On Reclaimed Mine Soils In Southwestern Wyoming, Alan T. Carpenter

All Graduate Theses and Dissertations, Spring 1920 to Summer 2023

Mined-land reclamation practices in shrub-steppe ecosystems can be augmented by planting seedlings of locally dominant shrubs, e.g., mountain big sagebrush. Dispersion pattern could affect sagebrush performance by influencing amounts of windborne snow, soil and litter which accumulate around shrubs and by influencing water withdrawal by roots. Mountain big sagebrush seedlings were planted in plots on a reclaimed coal strip mine in two dispersion patterns: singly and in clumps of four at the same overall density.

Performance of mountain big sagebrush was monitored during two growing seasons. Measures included plant survival, end-of-growing season aboveground biomass, leaf water potential components, soil water …

Internal Filters : Prospects For Uv-Acclimation In Higher Plants, Martyn M. Caldwell, Ronald Robberecht, Stephan D. Flint

Green Canyon Environmental Research Area, Logan Utah

Wavelength-selective absorption of solar radiation within plant leaves allows penetration of visible radiation to the chloroplats, while removing much of the damaging ultraviolet-B radiation. Flavonoids are important in this wavelength-selective absorption. Induction of flavonoid synthesis by solar radiation, and specifically by UV-B radiation, is discussed as this relates to the potential acclimation of plants to enhanced solar UV-B radiation that would result from stratospheric ozone reduction.

Age And Growth Of The Brown Trout Salmo Trutta Fario Linnaeus In Logan River, Utah, William Sigler

All Graduate Theses and Dissertations, Spring 1920 to Summer 2023

The Logan River flowing southwesterly through the mountains of Cache County, Utah is comparatively cold to the mouth of Logan Canyon. The stream is characterized by steep gradient, a high velocity and relatively few pools. A total of 1053 brown trout were examined during the course of this study; 286 were retained for age and growth determinations. The body-scale relationship is L = 40.46 mm. + 0.44185R + 0.01908R² where L equals standard length in millimeters, and R equals scale radius times 80. The relationship of standard length to weight is described by the formula W = 0.000022 L …