Other Forestry and Forest Sciences Commons^™

Senescent Trees Stabilize Aboveground Wood Net Primary Production Immediately After Disturbance, Maxim S. Grigri

Theses and Dissertations

In the United States, forests sequester 17% of national carbon (C) emissions annually (UGCRP, 2018), however shifting forest disturbances threaten the stability of this essential C sink. Unlike the high severity, stand-replacing disturbances that were widespread a century ago, today’s eastern temperate forests experience frequent low-to-moderate severity disturbances from invasive pests and pathogens with mixed effects on net primary production (NPP). Carbon cycling stability after disturbance has been reported, however, the mechanisms underlying immediate NPP stability or decline are not well understood. Through weekly measurements of production in a landscape scale experiment, we show that the sustained growth of senescent …

Interspecific Gene Flow Potentiates Adaptive Evolution In A Hybrid Zone Formed Between Pinus Strobiformis And Pinus Flexilis, Mitra Menon

Theses and Dissertations

Species range margins are often characterised by high degrees of habitat fragmentation resulting in low genetic diversity and higher gene flow from populations at the core of the species range. Interspecific gene flow from a closely related species with abutting range margins can increase standing genetic diversity and generate novel allelic combinations thereby alleviating limits to adaptive evolution in range margin populations. Hybridization driven interspecific gene flow has played a key role in the demographic history of several conifer due to their life history characteristics such as weak crossability barriers and long generation times. Nevertheless, demonstrating whether introgression is adaptive …

Aspen Growth Response In The Presence Of Inter-Annual Climate Fluctuation And Disturbance In The Lake Tahoe Basin, Keath K. Sakihara

Cal Poly Humboldt theses and projects

In the western US, aspen forests tend to be small and rare, but have great ecological importance. There is much interest and concern over how aspen in the Sierra Nevada Mountains of the western USA will respond to a changing climate and future disturbances. Impacts from climate change create stress on aspen trees that further compound threats to aspen communities. This analysis assessed the radial growth response of aspen under previously recorded climate conditions to better understand how measurable climate variables affect aspen growth. Along with aspen’s growth response to climate, this analysis also assessed the growth response of aspen …

Resource Selection And Calving Success Of Moose In Colorado, Forest P. Hayes

Graduate Student Theses, Dissertations, & Professional Papers

Across much of North America, moose populations (Alces alces) are declining due to disease, predation, climate, and anthropogenic pressures. Despite this, populations of moose in Colorado have continued to grow. Studying successful (i.e., persistent or growing) populations of moose can facilitate the continued conservation of the species by identifying habitat features critical for moose persistence.

First, I evaluated calving success of moose in Colorado and the impact of willow habitat quality and nutrition. I then estimated the probability of female moose having a calf using repeated observations in a Bayesian occupancy model. I assigned values for dry matter …

Comparison Of The Batch And Individual Log Study Methods For Use In Determining Log Breakeven Pricing, Levi Eric Sisler

Graduate Theses, Dissertations, and Problem Reports (ETD)

Understanding log yields and overrun is critical to a profitable sawmill operation. Lumber yield and overrun data can be gathered through one of two types of sawmill studies: batch studies or individual log studies. Little to no research has previously been conducted to determine if one method provides more reliable results than the other method. For this effort, 16 batch studies were conducted. Individual log studies were also conducted on the same logs, allowing a direct comparison of the results from both study types. A breakeven analysis was conducted for each study type, which determined the amount of variability in …

Stable Aggregate Dynamics And Carbon Storage In Acidified Forest Soils: Influence Of Atmospheric Deposition And Conifer Conversion At The Fernow Experimental Forest, J E. Kemner

Graduate Theses, Dissertations, and Problem Reports (ETD)

This research explored effects of ecosystem change from increased atmospheric nitrogen (N) deposition and stand conversion from mixed-species hardwood to Norway spruce in three experimental watersheds at the Fernow Experimental Forest (FEF). I measured soil aggregation and organic matter (OM) content to investigate the influence of forest fertilization in Watershed 3 (WS3), a hardwood forest receiving (NH₄)₂SO₄ fertilizer, versus Watershed 7 (WS7), a natural hardwood forest. I compared WS7 to Watershed 6 (WS6), a converted Norway spruce (Picea abies) monoculture. I quantified WS6 and WS7 C and N ecosystem pools, including vegetation biomass, …

Long-Term Study Of Prescribed Fire Effects On Stand Dynamics And Oak Regeneration Potentials In Degraded Upland Oak-Hickory Stands In Northwestern Arkansas, Mason C. Danheim, Kathryn R. Kidd Dr, Hal O. Liechty Dr, Brian P. Oswald Dr

Electronic Theses and Dissertations

Upland oak-hickory forests in the Ozark Mountains of northwestern Arkansas and south central Missouri were impacted by oak decline during the early 2000s. This decline event was caused by predisposing (e.g., mature, dense stand conditions), inciting (i.e., drought), and contributing (e.g., red oak borer, E. rufulus H., outbreak) factors. Immediately following onset of the decline, substantial crown dieback and tree mortality, particularly for two red oak species (northern red oak, Quercus rubra Michx. and black oak, Q. velutina Lam.), were observed. In addition, densities of advanced oak regeneration were inadequate at this time, resulting in poor regeneration potentials for …

Forests And Mental Health In South Africa: Panel Data Evidence, Dambala Gelo

Forest Collaborative Research

Slides from a presentation that examines the linkages between the green environment (urban forests, green open urban space) and mental health in South Africa. The author used representative panel data from the National Income Dynamics Survey, including the Center for Epidemiological Studies Short Depression Scale, to uncover these links.

Visitor Characteristics, Attitudes, And Management Preferences Of The Bob Marshall Wilderness Complex, Samuel J. Rhodes

Electronic Theses and Dissertations

The Bob Marshall Wilderness Complex (BMWC) encompasses 3 federal wilderness areas and spans over 1.5 million acres of iconic mountains and valleys in northwestern Montana. Here visitors can find a plethora of recreation opportunity that give access to some of the most rugged country that can be found in the lower 48 states. However, managing wilderness areas comes with the challenge of both preserving the natural resources found within their borders and enabling opportunities for recreational experiences. Wilderness social scientists always have striven to determine the type of visitors coming to wilderness, and see what sorts of experiences they pursue. …

Comparison Of The Survival And Growth Of West Gulf Coastal Plain Pine In East Texas, Jamie Hooker

Electronic Theses and Dissertations

West Gulf Coastal Plain provenance loblolly (Pinus taeda L.), longleaf (Pinus palustris Mill.), shortleaf (Pinus echinata Mill.), and slash pines (Pinus elliottii Engelm.) were planted in East Texas to compare initial growth and survival. Containerized seedlings were planted in December 2015 on three study sites in Shelby, Houston, and Cherokee counties using a randomized complete block design. Seedlings were measured in January-February 2016 and again January-February 2017, January 2018, and January 2019. Three years after planting, survival was best (76.4%) in Houston County and was lowest in Cherokee County (26.4). Damage by Texas leafcutter ants (Atta …

Synthesizing Conservation Motivations And Barriers: What Have We Learned From Qualitative Studies Of Farmers’ Behaviors In The United States?, Pranay Ranjan, Sarah P. Church, Kristin Floress, Linda S. Prokopy

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

Since 2011, qualitative studies examining adoption of conservation practices and programs (CPPs) have burgeoned. This article presents a systematic review of all U.S.-based qualitative investigations into CPP adoption since 1996. We found three themes are discussed primarily as motivating adoption: farmer characteristics, environmental awareness, and trust in information sources. Four themes are discussed primarily as barriers to adoption: farm management, negative perceptions of a conservation practice, perceptions that adoption is a risk, and land tenure. Four themes were discussed as both motivations and barriers: economic factors, social norms, perceptions of government programs, and farm characteristics. Overall, we found farmers’ economic …

Cogongrass (Imperata Cylindrica (L.) Beauv.) In Louisiana: Cause And Consequence, Lorissa A. Radunzel-Davis

LSU Master's Theses

Cogongrass (Imperata cylindrica (L.) Beauv.), an invasive species from East Asia, is found worldwide and is problematic in several countries. In the United States, it grows primarily in the Southeast, reducing biodiversity by growing in dense patches and potentially causing mortality and reducing value of native and planted pinelands due to a high burning temperature. Using Lee Memorial Forest, a Louisiana State University AgCenter property in Washington Parish as a study site, this thesis explores cogongrass in Louisiana with emphasis on soil microbes and soil legacy effects on native plant species. Cogongrass populations at Lee Memorial Forest were more …

Matrix Recharge In A Shrink-Swell Floodplain Forest Soil, Savannah R. Morales

LSU Master's Theses

Despite the global distribution of fine-grained Vertisols, the hydrology of these floodplain soils is still not well understood. Vertisols shrink and swell depending on soil moisture leading to a range of soil pore sizes, from large macropore cracks to smaller micropores, and consequently a range of hydraulic conductivities. Despite the plethora of research indicating the importance of both flooding and soil moisture in floodplain ecosystems, the specific role that flooding plays in soil moisture recharge has been less widely studied and remains of interest. Blue food dye and deuterated water were used as tracers to determine the role of the …

Integration Of Random Forest Classifiers And Deep Convolutional Neural Networks For Classification And Biomolecular Modeling Of Cancer Driver Mutations, Steve Agajanian, Odeyemi Oluyemi, Gennady M. Verkhivker

Mathematics, Physics, and Computer Science Faculty Articles and Research

Development of machine learning solutions for prediction of functional and clinical significance of cancer driver genes and mutations are paramount in modern biomedical research and have gained a significant momentum in a recent decade. In this work, we integrate different machine learning approaches, including tree based methods, random forest and gradient boosted tree (GBT) classifiers along with deep convolutional neural networks (CNN) for prediction of cancer driver mutations in the genomic datasets. The feasibility of CNN in using raw nucleotide sequences for classification of cancer driver mutations was initially explored by employing label encoding, one hot encoding, and embedding to …

Enhancing Rural Economies Through Agroforestry, Gary Bentrup, Dean Current, Christopher Hartley, Marlen Eve, Tricia Kovacs, Kate Mcfarland, Eric Norland, David Smith, Susan Stein, Richard Straight

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

Executive Summary

Accelerating the adoption of agroforestry will require a better understanding of the economic opportunities and financial benefits to society, says a recent assessment of United States agroforestry.1 Providing this understanding is critical for agroforestry to reach its full potential, whereby it enhances rural economies and provides ecological services that people need, such as clean drinking water. To assess emerging opportunities, the United States Department of Agriculture (USDA) convened more than 60 people in March 2018 to learn, network, and, above all, generate ideas for raising the economic profile and viability of agroforestry in the United States.

The effort …

Forest Feedstock Supply Chains And Market Potential For Wood Pellet Facilities In The Ozark And Appalachia Regions, James Robert Criger

Graduate Theses/Dissertations

The pellet wood industry in the United States has grown exponentially in recent years, due mostly to the expanding export market to Europe. At this time, the European market for pellet wood is highly subsidized as part of the Renewable Energy Directive (RED) in an effort to mitigate fossil fuel consumption for power production. Although there are other popular renewable resources such as wind, water, and solar, the burning of biomass is among the most utilized sources of renewable energy today. This study examines the existing pellet wood industry in the United States, particularly within the Ozarks and Appalachia Regions, …

Forest Structure Of Long-Term Conserved Areas Utilizing Different Strategies On A Continental, Glacial Moraine Formed Island, Christopher Coggin

Masters Theses, 2010-2019

Understanding patterns of forest succession can help advise management plans within New England nature preserves. This study took place on Block Island, 13 miles off the coast of Rhode Island. The island has greater than 200+ years of farming practices. After 1960, conservation groups began reforesting the island using different strategies, such as actively planting with native and exotic tree species, mowing, and preventing further development. In 2018, woody vegetation was inventoried along transects within four reforested sites. Sites were characterized as the following: actively planted with exotic and native tree species and mowed (AP-M), actively planted with exotic and …

A Qualitative Case Study Of Student Persistence In A Bachelor Of Science In Forestry Program, Maxwell Holmes

Electronic Theses and Dissertations

Educational leaders in forestry have been challenged to increase and diversify the pipeline of ‘society ready’ foresters. To meet these challenges, leaders must shift their focus to student retention. By understanding the factors that influence student engagement and persistence, these leaders will be better positioned to support students in forestry programs, thus positively impacting retention. This qualitative case study investigated student persistence of second-year forestry students in an undergraduate forestry program. The study was guided by Social Cognitive Theory and Social Capital Theory and explored the malleable psychosocial mechanisms of self-efficacy, sense of belonging, emotion, and well-being proposed by Kahu …

Using The Forestry Reclamation Approach For Reclaimed Surface Mineland In The Western Gulf: Effects On Pinus Taeda Seedling Growth And Survival, Cassie Phillips, Jeremy Stovall, Hans Williams, Kenneth Farrish

Electronic Theses and Dissertations

While land reclamation efforts of surface mines have considerably increased soil stability since the implementation of SMCRA (Surface Mining Control and Reclamation Act), research suggests that resulting soil compaction hinders the productivity of forests post-mining. The Forestry Reclamation Approach (FRA) was developed to improve forest health in the Appalachian region through a five-step process that minimizes soil compaction and establishes a productive forest. The FRA has not yet been tested in the western Gulf Coastal Plain (GCP). The higher clay content of some GCP soils and the dearth of coarse fragments (e.g. cobbles, stones and boulders) may affect reclamation practices …

Outdoor Education’S Relationship To Adolescent Behavior And Academic Performance In Two East Texas Middle Schools, Trenton Stiefel

Electronic Theses and Dissertations

Historically, a key part of a child’s development was their exposure to and relationship with the world outdoors – nature. The current movement to promote the inclusion of environmental and outdoor education into curricular and extracurricular activities stems from the mounting evidence that experiences in the outdoors may improve a child’s behavior and mood, as well as improve their academic performance. This mixed-methods study hoped to discover whether or not, on average, children improve their academic performance and/or their individual behavior in school when provided with outdoor education learning experiences. The mindset used in outdoor education research may have to …