Life Sciences Commons^™

Using Biophysical Geospatial And Remotely Sensed Data To Classify Ecological Sites And States, Carson A. Stam

All Graduate Theses and Dissertations, Spring 1920 to Summer 2023

Within the Intermountain West, vast expanses of big sagebrush shrubland and steppe are considered emblems of the western range. Currently, there are approximately 60 million hectares of big sagebrush within the 11 western states, four million of which are in the state of Utah. However, the historic distribution of sagebrush has been impacted by conversion to other types of land cover through juniper encroachment, urbanization, invasive weeds, and agricultural expansion. In Utah alone, big sagebrush communities have been reduced to approximately 55% of their historic extent. A primary and current example of the cumulative impact of big sagebrush loss is …

Characterizing Water And Nitrogen Dynamics In Urban/Suburban Landscapes, Hongyan Sun

All Graduate Theses and Dissertations, Spring 1920 to Summer 2023

This research investigated the water use of different plant types in urban landscapes, nitrogen (N) and water transport in turf, and potential N leaching from urban landscapes to ground water. In the first study, three landscape treatments integrating different types of plants—woody, herbaceous perennial, turf—and putative water use classifications—Mesic, Mixed, Xeric—were grown in large drainage lysimeters. Each landscape plot was divided into woody, turf, and herbaceous perennial plant hydrozones and irrigated for optimum water status over two years, with water use measured using a water balance approach. For woody plants and herbaceous perennials, canopy cover, rather than plant type or …

Object-Based Segmentation And Classification Of One Meter Imagery For Use In Forest Management Plans, W. Kevin Wells

All Graduate Theses and Dissertations, Spring 1920 to Summer 2023

This research developed an ArcGIS Python model that extracts polygons from aerial imagery and assigns each polygon a vegetation type based on a modified set of landcover classes from the Southwest Regional Gap Analysis Project. The model showed an ability to generate polygons that accurately represent vegetation community boundaries across a large landscape. The model is for use by the Utah Division of Forestry, Fire, and State Lands to assist in the preparation of forest management plans. The model was judged useful because it was easy to use, it met a designated 50% threshold of useable polygons, and it met …

Assessing Quaking Aspen (Populus Tremuloides) Decline On Cedar Mountain In Southern Utah Using Remote Sensing And Geographic Information Systems, Chad M. Oukrop

All Graduate Theses and Dissertations, Spring 1920 to Summer 2023

Quaking aspen (Populus tremuloides Michx.) is the most widespread deciduous tree species in North America and aspen ecosystems are highly valued for multiple use, being noted for forage production, understory diversity, wildlife habitat, timber, hydrological assets, and aesthetics. However, aspen communities in the Intermountain Region of the western United States are in evident decline, with certain areas experiencing rapid mortality over the past decade. One location of special interest is the quaking aspen on Cedar Mountain in Southern Utah, USA, an isolated population in the southwestern portion of aspen's geographic range.

Lacking critical information on the location, extent, and …

Modeling Bark Beetle Outbreak And Fire Interactions In Western U.S. Forests And The Invasion Potential Of An Invasive Puerto Rican Frog In Hawaii Using Remote Sensing Data, Simon A. Bisrat

All Graduate Theses and Dissertations, Spring 1920 to Summer 2023

I used Moderate-Resolution Imaging Spectroradiometer (MODIS) imagery to answer two ecological questions. In the first project, I investigated the interactions between bark beetle-caused tree mortality and fire occurrence in western U.S. forests. I used remotely sensed fire data detected by MODIS satellite and bark beetle-caused tree mortality data. I tested the hypothesis that there is an increased probability of fire incidence in bark beetle-damaged forests compared to healthy forests using conditional probability modeling across the national forests of the western U.S. regardless of forest type. My results did not show a consistent pattern (increase or decrease of conditional probability of …

Modeling Potential Native Plant Species Distributions In Rich County, Utah, Kathryn A. Peterson

All Graduate Theses and Dissertations, Spring 1920 to Summer 2023

Georeferenced field data were used to develop logistic regression models of the geographic distribution of 38 frequently common plant species throughout Rich County, Utah, to assist in the future correlation of Natural Resources Conservation Service Ecological Site Descriptions to soil map units. Field data were collected primarily during the summer of 2007, and augmented with previously existing data collected in 2001 and 2006. Several abiotic parameters and Landsat Thematic Mapper imagery were used to stratify the study area into sampling units prior to the 2007 field season.

Models were initially evaluated using an independent dataset extracted from data collected by …

Statmod: A Tool For Interfacing Arcview® Gis With Statistical Software To Facilitate Predictive Ecological Modeling, Christine M. Garrard

All Graduate Theses and Dissertations, Spring 1920 to Summer 2023

As geographical information systems and spatial data become more accessible, predictive spatial modeling in ecology is becoming more common. Unfortunately, not all ecologists possess the necessary skills to successfully combine statistical models and geographical information systems. In response to this problem, I wrote an extension for ArcView^® GIS called StatMod. This extension interfaces ArcView GIS with SAS^® and S-PLUS^® statistical software and walks the user through creating and mapping logistic regression and classification and regression tree models.

StatMod was then used to run a series of analyses that would have been difficult without such a tool. A …

A Geographic Information System Assessment Method For Fire Management: Identifying Fire Danger Areas, Richard D. Stratton

All Graduate Theses and Dissertations, Spring 1920 to Summer 2023

In partnership with the USDA Forest Service and the Utah Division of Forestry, Fire, and State Lands, a geographic information system (GIS) was used to create a wildland fire assessment methodology. GIS layers (or themes) include topography, infrastructure, vegetation, climate, "sensitive" natural values, and fire history. Two phases of assessment are presented: a preliminary analysis designed for planning use at the landscape level, and a detailed analysis for site-specific use.

Results of the phase 1 assessment are density grids delineating areas of high fire occurrence and suggesting to managers where a phase 2 assessment is needed. By using the environmental, …