Other Forestry and Forest Sciences Commons^™

Long-Term Changes In Four Plant Communities Along An Elevational Gradient In The Front Range Of Colorado, Gregory J. Sproull

Electronic Theses and Dissertations

We surveyed four plant communities along an elevational gradient in the Front Range of the Colorado Rocky Mountains for long-term overstory and understory changes. Our results were compared to those found in 1981 and 1996. We evaluated changes in succession, elevational species migration and range expansion, community diversity, and composition. We related temporal floristic shifts to prior literature on disturbance history at each site. Over time, all communities changed significantly, though in different manners. This analysis shows that plant communities are changing in dynamic and idiosyncratic ways that correspond to individualistic distribution shifts. Moreover, we exhibit the necessity of comprehensively …

Producing “Society-Ready” Foresters: A Research-Based Process To Revise The Bachelor Of Science In Forestry Curriculum At Stephen F. Austin State University, Steven H. Bullard, Pat Stephens Williams, Theresa Coble, Dean W. Coble, Ray Darville, Laurie Rogers

Faculty Publications

“Society-ready” foresters are capable of dealing effectively with the complex economic, ecological, and social issues involving forestry in the 21st century. To assess the knowledge areas, skill sets, abilities, and behaviors needed by society-ready, entry-level foresters today, we surveyed 800 forestry employers and forestry alumni from Stephen F. Austin State University (SFASU), and we also conducted focus group sessions with a total of 58 forestry employers. Important areas of knowledge on emerging issues for society-ready Bachelor of Science in Forestry (BSF) graduates included climate change, water availability and quality, and dealing with invasive plants, pathogens, and insects. However, the skill …

Development And Evaluation Of High Resolution Simulation Tools To Improve Fire Weather Forecasts, Brian K. Lamb, Jason M. Forthofer, Peter R. Robichaud

Joint Fire Science Program Research Project Reports

Fire weather forecasts rely on numerical weather simulations where the grid size is 4 km x 4 km or larger. In areas of complex terrain, this model resolution will not capture the details of wind flows associated with complicated topography. Wind channeling in valleys, wind speed-up over mountains and ridges, and enhanced turbulence associated with rough terrain and tall forest canopies are poorly represented in current weather model applications. A number of numerical wind flow models have been developed for simulating winds at high resolution; however, there are limited observational data available at the spatial scales appropriate for evaluating these …

Exploring How Deliberation On Scientific Information Shapes Stakeholder Perceptions Of Forest Management And Climate Change, Troy E. Hall, Jarod J. Blades

Joint Fire Science Program Research Project Reports

Climate change has resulted in rapid biophysical changes in forests of the western U.S. and has prompted the need for an increased understanding of potential impacts and adaption measures. Land managers, policy makers, and community officials lack locally relevant climate change science and are urgently calling for research to inform management decisions. Nevertheless, a substantial disconnect remains between emerging scientific information and its application in management decisions. Effective action depends on understanding regional and local implications of climate change and open, reasoned discussions about current research and potential mitigation actions among researchers, land managers, and other stakeholders. Boundary objects have …

Fire Effects On Seedling Establishment Success Across Treeline: Implications For Future Tree Migration And Flammability In A Changing Climate, F. S. Chapin Iii, Teresa N. Hollingsworth, Rebecca E. Hewitt

Joint Fire Science Program Research Project Reports

Understanding the complex mechanisms controlling treeline advance or retreat in the arctic and subarctic has important implications for projecting ecosystem response to changes in climate. Changes in landcover due to a treeline biome shift would alter climate feedbacks (carbon storage and energy exchange), ecosystem services such as wildlife and berry habitat, and landscape flammability. Wildfire frequency and extent has increased in the last half-century in the boreal forest and tundra in response to warmer weather and lower precipitation. Invasion of tundra by trees may be facilitated by wildfire disturbance, which exposes new seedbeds, increases nutrient availability immediately post-fire, and creates …

Drought-Induced Woody Plant Mortality In An Encroached Semi-Arid Savanna Depends On Topoedaphic Factors And Land Management, Dirac L. Twidwell Jr, Carissa L. Wonkka, Charles A. Taylor, Chris B. Zou, Jeremiah J. Twidwell, William E. Rogers

Department of Agronomy and Horticulture: Faculty Publications

Questions: How do recent patterns of drought-induced woody plant mortality in Texas semi-arid savanna compare to the extended drought of the 1950s? Does the relative composition of the woody plant community shift ubiquitously across the landscape following woody plant mortality and dieback or are shifts dependent on differences among species, soils, land use and plant demography?

Location: Texas Agrilife Research Station, Sonora, Texas, USA (30.1° N 100.3° W).

Methods: Following an exceptional drought from 1951 to 1957, a study was conducted to quantify rates of mortality for various woody plant species. In 2011, we repeated this study within three long-term …

Growth Of Black Walnut In Southeast Nebraska, Benjamin A. Loseke, Dennis M. Adams

Nebraska Forest Service: Publications

Black walnut (Juglans nigra L.), within the family Juglandaceae, is a premier hardwood timber species in the United States. Its native range encompasses most of the eastern U.S., roughly extending from eastern South Dakota and eastern Texas on its western edge to Massachusetts and western Florida in the east (Figure 1). The occurrence and productivity of black walnut on the western edge of its native range, including eastern Nebraska, is largely a function of available water during the growing season. However, black walnut has been extensively planted west and north of its native range. Studies have shown black walnut can …

Nitrogen And Carbon Dynamics In Prairie Vegetation Strips Across Topographical Gradients In Mixed Central Iowa Agroecosystems, Marlin Perez-Suarez, Michael J. Castellano, Randall Kolka, Heidi Asbjornsen, Matthew J. Helmers

United States Department of Agriculture, Forest Service / University of Nebraska-Lincoln: Faculty Publications

Reductions of nitrogen (N) export from agricultural lands because of changes in specific N stocks andfluxes by incorporation of small amounts of prairie vegetation strips (PVS) are poorly understood. Theprimary objective of this study was to evaluate the effect of the presence and topographical position of PVSon soil and plant carbon (C) and N stocks relative to annual crop and native prairie vegetation. The studywas implemented within three small adjacent watersheds, treated with one of the following cover types:(1) 100% row-crop agriculture (CROP); (2) 20% prairie vegetation (PVS) distributed along the contouracross three topographical positions: upslope, sideslope and footslope position; …

Recovery Of Wolverines In The Western United States: Recent Extirpation And Recolonization Or Range Retraction And Expansion?, Kevin S. Mckelvey, Keith B. Aubry, Neil J. Anderson, Anthony P. Clevenger, Jeffrey P. Copeland, Kimberley S. Heinemeyer, Robert M. Iman, John R. Squires, John S. Waller, Kristine L. Pilgrim, Michael K. Schwartz

United States Department of Agriculture, Forest Service / University of Nebraska-Lincoln: Faculty Publications

Wolverines were greatly reduced in number and possibly extirpated from the contiguous United States (U.S.) by the early 1900s. Wolverines currently occupy much of their historical range in Washington, Idaho, Montana, and Wyoming, but are absent from Utah and only single individuals are known to occur in California and Colorado. In response, the translocation of wolverines to California and Colorado is being considered. If wolverines are to be reintroduced, managers must identify appropriate source populations based on the genetic affinities of historical and modern wolverine populations. We amplified the mitochondrial control region of 13 museum specimens dating from the late …

Housing Development Erodes Avian Community Structure In U.S. Protected Areas, Eric M. Wood, Anna M. Pidgeon, Volker C. Radeloff, David Helmers, Patrick D. Culbert, Nicholas S. Keuler, Curtis H. Flather

United States Department of Agriculture, Forest Service / University of Nebraska-Lincoln: Faculty Publications

Protected areas are a cornerstone for biodiversity conservation, but they also provide amenities that attract housing development on inholdings and adjacent private lands. We explored how this development affects biodiversity within and near protected areas among six ecological regions throughout the United States. We quantified the effect of housing density within, at the boundary, and outside protected areas, and natural land cover within protected areas, on the proportional abundance and proportional richness of three avian guilds within protected areas. We developed three guilds from the North American Breeding Bird Survey, which included Species of Greatest Conservation Need, land cover affiliates …

Performance Of Species Richness Estimators Across Assemblage Types And Survey Parameters, Gordon C. Reese, Kenneth R. Wilson, Curtis H. Flather

United States Department of Agriculture, Forest Service / University of Nebraska-Lincoln: Faculty Publications

Aim A raw count of the species encountered across surveys usually underestimates species richness. Statistical estimators are often less biased. Nonparametric estimators of species richness are widely considered the least biased, but no particular estimator has consistently performed best. This is partly a function of estimators responding differently to assemblage-level factors and survey design parameters. Our objective was to evaluate the performance of raw counts and nonparametric estimators of species richness across various assemblages and with different survey designs.

Location We used both simulated and published field data.

Methods We evaluated the bias, precision and accuracy of raw counts and …

Spatial Patterns And Physical Factors Of Smokejumper Utilization Since 2004, Tyson A. Atkinson

Graduate Student Theses, Dissertations, & Professional Papers

This research examines patterns of aerial smokejumper usage in the United States. I assess landscape and environmental factors of their deployment using a detailed nine-year record of smokejumper activity in combination with terrain, fuels, and transportation network data. Specifically, the research seeks to identify commonalities in location (proximity), terrain, fuels, fire occurrence, and accessibility of smokejumper actions that inform current usage and identify opportunities for improved utilization. Terrain parameters (steep, rugged, inaccessible) of the western U.S. were classified and a baseline travel time grid was created (30 meter resolution). Fires in which smokejumpers responded were compared with all fires that …

Effects Of Road-Stream Crossings On Populations Of The Idaho Giant Salamander (Dicamptodon Aterrimus), Richard K. Honeycutt

Graduate Student Theses, Dissertations, & Professional Papers

Habitat disturbances affect wildlife populations through numerous mechanisms, and determining specific components of habitat disturbances affecting those populations is challenging. For example, a single disturbance can both change local habitat conditions and impose limitations on dispersal of animals. Both of these components can negatively affect biological responses, such as body condition, local movement patterns, or survival. Culverts are a habitat disturbance having both of these components. Culverts affect local habitat conditions by increasing sediment levels in downstream reaches, negatively affecting animals downstream of culverts. Culverts also impose limits on dispersal by blocking passage of stream organisms to upstream reaches, negatively …

Heat Transfer Characteristics In Wildland Fuelbeds, Justin English

Theses and Dissertations--Mechanical and Aerospace Engineering

The fundamental physics governing wildland fire spread are still largely misunderstood. This thesis was motivated by the need to better understand the role of radiative and convective heat transfer in the ignition and spread of wildland fires. The focus of this work incorporated the use of infrared thermographic imaging techniques to investigate fuel particle response from three different heating sources: convective dominated heating from an air torch, radiative dominated heating from a crib fire, and an advancing flame front in a laboratory wind tunnel test. The series of experiments demonstrated the uniqueness and valuable characteristics of infrared thermography to reveal …

Effects Of Regeneration Opening Size And Simulated Crop Tree Release On Volume Yields And Economic Value In Oak-Dominated Stands, Russell Andrew Cunningham

Theses and Dissertations--Forestry and Natural Resources

Patch clearcutting can be put to effective use for landowners with relatively small stands of timber. This project was designed to determine how clearcut opening size and mid-rotation crop tree release affects the value and volume of sawtimber at the end of rotation. In 1960 patch clearcuts were established in three different diameters, 50ft (.05ac), 150ft (.41ac), and 250ft (1.13ac). Current stand data (2011) was collected to determine trees per acre, basal area, average tree diameter, volume, and value. These data were input into a growth simulator to determine future trees per acre, basal area, average tree diameter, volume, and …

The Distance From Necessity: A Bourdieusian Analysis Of Gathering Practices In Vermont, Alan Robert Pierce

Antioch University Dissertations & Theses

This study examines why contemporary Americans continue to gather wild plants and fungi. Vermont, a state with a rich history of gathering, serves as a study site. I interviewed twenty-four gatherers using ethnographic methods. I applied a Bourdieusian framework to analyze the differences between gathering practices as they related to gathering knowledge, views of nature, and uses of gathered products. The interviews indicated that gathering is important to the physical and mental well-being of its practitioners and instills a connection to nature as well as to place. Interviewees cited spending time in nature and enjoyment of engaging the senses as …

Genetic Variation, Local Adaptation And Population Structure In North American Red Oak Species, Quercus Rubra L. And Q. Ellipsoidalis E. J. Hill, Jennifer F. Lind-Riehl

Dissertations, Master's Theses and Master's Reports - Open

Forest trees, like oaks, rely on high levels of genetic variation to adapt to varying environmental conditions. Thus, genetic variation and its distribution are important for the long-term survival and adaptability of oak populations. Climate change is projected to lead to increased drought and fire events as well as a northward migration of tree species, including oaks. Additionally, decline in oak regeneration has become increasingly concerning since it may lead to decreased gene flow and increased inbreeding levels. This will in turn lead to lowered levels of genetic diversity, negatively affecting the growth and survival of populations. At the same …

Illuminating Capacity-Building Strategies For Landscape-Scale Collaborative Forest Management Through Constructivist Grounded Theory, Marcelle Elise Dupraw

Department of Conflict Resolution Studies Theses and Dissertations

This dissertation uses the constructivist grounded theory methods of Charmaz (2011) to explore: 1) the unique characteristics of landscape-scale collaboration; 2) implications for collaborative capacity-building strategies; and 3) the relationship between conflict, landscape-scale collaboration, and conflict resolution. The study was conducted through the US Forest Service's Collaborative Forest Landscape Restoration Program (CFLRP). In the 1980s and 1990s, national forest management conflicts brought the forest industry to a standstill, with many jobs lost. In addition, historic fire suppression practices have made our national forests highly vulnerable to catastrophic wildfire. Many have strong opinions about what should be done and how. The …

Developing Strategies To Initialize Landscape-Scale Vegetation Maps From Fia Data To Enhance Resolution Of Individual Species-Size Cohort Representation In The Landscape Disturbance Model, Simpplle, Jacob Muller

Graduate Student Theses, Dissertations, & Professional Papers

The ability of forest resource managers to understand and anticipate landscape-scale change in composition and structure relies upon an adequate characterization of the current forest composition and structure of various patches (or stands), along with the capacity of forest landscape models (FLMs) to predict patterns of growth, succession, and disturbance at multiple scales over time. Comprehensive vegetation maps, which classify patch polygons or raster cells into forest cover types, can be developed from available inventory data (e.g., FIA Grid) in combination with remotely sensed data, but a simple categorical forest type, even one incorporating average size, may not provide adequate …