Forest Sciences Commons^™

Human Dimensions Of Woody Encroachment Management In Nebraska, Emily Rowen

School of Natural Resources: Dissertations, Theses, and Student Research

Woody plant encroachment (WPE) is a social-ecological problem that will challenge conservation professionals and agricultural producers to adapt their management strategies. This research first examined WPE from the perspective of individual conservation professionals through an online survey. Conservation professionals’ attitudes about adaptation to vegetation transitions, such as WPE, were of interest because these attitudes are one measure of how prepared this group is to respond to WPE. Hypothesized predictors of adaptation attitude were tested through linear regression modeling. These predictors included ecological change, observation of WPE, or risk perception. It was found that risk perception was the strongest predictor of …

Soil Succession: Short And Long-Term Impacts Of Grazing On Soil Properties In A Tropical Montane Cloud Forest, June Curtis

Independent Study Project (ISP) Collection

Cattle ranching is the leading cause of deforestation in South America, causing long-lasting alterations to the continent's landscape and ecology. Tropical montane cloud forests (TMCFs) are a rare ecosystem particularly vulnerable to the effects of land conversion to pasture, a process which has implications ranging from biodiversity loss to soil degradation. Grazing is known to significantly alter soils' physical structure through processes of compaction and erosion as well as significant additions of organic matter. Silvopasture, or the integration of pasture and forest, has emerged as an alternative to traditional grazing practices with the hope of mitigating environmental and soil degradation. …

Willow Abundance And Condition Mapping In Rocky Mountain National Park, Eric M. Nielsen

Institute for Natural Resources Publications

Riparian and wetland willow species have undergone serious declines in Rocky Mountain National Park as a consequence of a variety of environmental changes and, most recently, damage resulting from moose overpopulation. To address concerns about the long-term status of willows in the park, we developed remote sensing-based raster maps of riparian and wetland willow species presence, canopy cover percentage, canopy height, and leaf area index. All outputs were produced at 3-meter resolution, and represent willows as they existed in 2021. The mapping was performed via random forests classification and regression models trained on several hundred vegetation plots from a variety …

Agroforestry For The Future: Motivations Behind Tasmanian Farmers Planting Trees, Josh Lipp

Independent Study Project (ISP) Collection

Agroforestry is the act of combining farming and tree planting, and many Tasmanian farmers are starting to plant trees on their properties for multiple reasons. Through conducting 9 interviews with farmers and researchers and visiting field sites, 3 main themes were identified to answer the question: why are Tasmanian farmers planting trees, and what are the benefits and downsides to agroforestry? Interviews help us understand farmers’ perceptions of agroforestry, and field data collection will prove the benefits of agroforestry in the future. Tasmania was chosen as the location of study as it is a state in Australia that largely focuses …

Assessing Functional Biodiversity For The Future Of Plants, Planet, And People, Ali Loker

Doctor of Plant Health Program: Dissertations and Student Research

Biodiversity plays a critical role in supporting life in global ecosystems and its links to ecosystem services and sustainability are recognized by scientific and non-scientific communities. Growing awareness of the importance of biodiversity is accelerated by discussions of its loss, and how to design interventions to conserve and mitigate a biodiversity crisis. Stakeholders are funding and implementing assessment strategies at various scales to help direct conservation efforts. There is also growing interest in measuring and communicating biodiversity outcomes.

Functional biodiversity characterizes the multiplicity of life forms into groups based on their diverse contributions to natural and agro-ecosystems. Assessing functional biodiversity …

Estimating Northern Spotted Owl (Strix Occidentalis Caurina) Pair Detection Probabilities Based On Call-Back Surveys Associated With Long-Term Mark-Recapture Studies, 1993–2018, Katie M. Dugger, Alan B. Franklin, Damon B. Lesmeister, Raymond J. Davis, J. David Wiens, Gary C. White, James D. Nichols, James E. Hines, Charles B. Yackulic, Carl J. Schwarz, Steven A. Ackers, L. Steven Andrews, Larissa L. Bailey, Robin Bown, Jesse Burgher, Kenneth P. Burnham, Peter C. Carlson, Tara Chestnut, Mary M. Conner, Krista E. Dilione, Eric D. Forsman, Scott A. Gremel, Keith A. Hamm, Dale R. Herter, J. Mark Higley, Rob B. Horn, Julianna M. Jenkins, William L. Kendall, David W. Lapmphear, Christopher Mccafferty, Trent L. Mcdonald, Janice A. Reid, Jeremy T. Rockweit, David C. Simon, Stan G. Sovern, James K. Swingle, Heather Wise

USDA Wildlife Services: Staff Publications

The northern spotted owl (Strix occidentalis caurina; hereinafter NSO) was listed as “threatened” under the Endangered Species Act in 1990 and population declines have continued since that listing. Given the species’ protected status, any proposed activities on Federal lands that might impact NSO require consultation with U.S. Fish and Wildlife Service and part of that consultation often includes surveys to determine presence and occupancy status of the species in the proposed activity area. The objective of this report is to present study-area specific estimates of the probability of detection for NSO pairs from twelve 2-week seasonal survey periods …

Nexus Between Animal Welfare, Environment, And Sustainable Development: Resource Document, Wellbeing International

Nexus – UNEP – Animal Welfare, Environment, Sustainable Development

This Resource Document has been developed to explore the Nexus (links) between Animal Welfare, the Environment, and Sustainable Development. The document includes relevant citations and reports addressing the topics encompassed by the Nexus. It will be maintained as a “living document” (subject to revision) in the WellBeing International Studies Repository. The original document and subsequent revisions will be kept in the Repository to provide a record of the changes.

Monitoring Whitebark Pine Stand Health In The Central Washington Cascades, Nancy H. Parra, Teresa J. Lorenz, Taza D. Schaming, Alison Scoville

Student Published Works

Whitebark pine (Pinus albicaulis) plays a vital role in colonizing newly disturbed areas, providing shade for other tree species to germinate, and supplying food for a variety of birds and mammals, such as Clark’s Nutcrackers (Nucifraga columbiana) and grizzly bears (Ursus arctos horribilis). Decline of whitebark pine populations has been attributed to several factors, including white pine blister rust (Cronartium ribicola), mountain pine beetle (Dendroctonus ponderosae) outbreaks, and fire exclusion. In 2009, the U.S. Forest Service began to install permanent plots in whitebark pine stands in Washington and Oregon as …

Disturbance Reduces Fungal White-Rot Litter Mat Cover In A Wet Subtropical Forest, D. Jean Lodge, Ashley E. Van Beusekom, Grizelle González, Mareli Sánchez-Julia, Sarah Stankavich

USDA Forest Service / UNL Faculty Publications

Fungi that bind leaf litter into mats and produce white-rot via degradation of lignin and other aromatic compounds influence forest nutrient cycling and soil fertility. Extent of white-rot litter mats formed by basidiomycete fungi in Puerto Rico decreased in response to disturbances—a simulated hurricane treatment executed by canopy trimming and debris addition in 2014, a drought in 2015, a treefall, and two hurricanes 10 days apart in September 2017. Percent fungal litter mat cover ranged from 0.4% after Hurricanes Irma and Maria to a high of 53% in forest with undisturbed canopy prior to the 2017 hurricanes, with means mostly …

Annals Of Forest Science Promotes Multidisciplinary Research On Forests And Wood In A Changing World And Is Now A Full Open Access Journal, Erwin Dreyer, Jean Michel Leban, Shuguang Léo Liu, Andreas Bolte, John M. Lhotka, Marco Ferretti, Véronique Lesage

Forestry and Natural Resources Faculty Publications

No abstract provided.

Soil Microbial Community Dynamics In Response To Prescribed Extreme Fires Following Juniperus Virginiana Invasion In The Loess Canyons Of Nebraska, Julie A. Fowler

School of Natural Resources: Dissertations, Theses, and Student Research

In Nebraska and other regions of the Great Plains, the conifer Juniperus virginiana (eastern redcedar) is converting grasslands to dense woodlands. This is driven by the interacting drivers of fire suppression, altered grazing regimes, climate change and other anthropogenic factors, impacting the provisioning of ecosystem services. This vegetation state transition modifies water resource regulation and biogeochemical cycles leading to altered edaphic properties including soil microbial community composition. To restore these grasslands and control J. virginiana spread, prescribed extreme burns are implemented as a management tool through local prescribed burn associations. We hypothesized that the alternative state transition to dense J. …

Tapping The Sweet Spot: Predicting The Suitability Of A Woodlot’S Potential To Transition Into A Productive Sugarbush In Maine, Deven M. Teisl

Non-Thesis Student Work

Through conversations with Dr. Sara Velardi, a postdoctoral research associate who has been doing research on maple producers’ scale management decisions in Maine, most current owners and operators in the maple syrup industry have the common interest of expanding their current operations, but they are unsure of how to approach that problem. Due to these current issues, my research focused on creating a sugarbush assessment tool. This assessment tool consists of a set of guidelines which can be utilized by current or future producers and can be used to easily assess woodlots without having to hire a consulting forester to …

Reviewing Fire, Climate, Deer, And Foundation Species As Drivers Of Historically Open Oak And Pine Forests And Transition To Closed Forests, Brice B. Hanberry, Marc D. Abrams, Mary A. Arthur, J. Morgan Varner

Forestry and Natural Resources Faculty Publications

Historically open oak and pine savannas and woodlands have transitioned to closed forests comprised of increased numbers of tree species throughout the eastern United States. We reviewed evidence for and against a suite of previously postulated drivers of forest transition focused on (1) change in fire regimes, (2) increased precipitation, (3) increased white-tailed deer densities, and (4) loss of American chestnut. We found that fire and fire exclusion provide a parsimonious mechanism for historical dominance by open forests of fire-tolerant oak and/or pine species and subsequent transition to closed forests with fire-sensitive tree species that fill the vertical profile. Based …

Green Strategic Planning Approach For International Shipping Activities, Xiaofang Wu, Luoping Zhang, Huan Feng

Department of Earth and Environmental Studies Faculty Scholarship and Creative Works

Sustainability is a long-term and ultimate goal for international shipping, although it is slowly making progress. The shipping perspective that moves away from “port-to-port” operations to “door-to-door” services also requires international shipping to take a long-term and holistic view instead of fragmented efforts. How to achieve the long-term sustainability goal becomes a key issue for door-to-door international shipping. Hence, green strategic planning for door-to-door international shipping was proposed with green development that puts forward the eco-centric point of view as its basic theory for sustainability. This study used a strategic decision-making approach, a so-called multi-dimensional decision-making (MDDM), coupled with the …

Stakeholders’ Perceptions Of Geographical Criteria For Loblolly Pine Management For Bioenergy Production In Virginia, Meghann Smith, Gia Nguyen, Taylor Wieczerak, Bernabas Wolde, Pankaj Lal, John Munsell

Department of Earth and Environmental Studies Faculty Scholarship and Creative Works

This study analyzed the perceptions of four stakeholder groups (forest landowners, private forest consultants, forest management researchers or educators, and federal or state agency foresters), regarding their management practices and preferred geographic growing conditions of loblolly pine in Virginia by combining AHP (analytical hierarchy process) and regression modeling. By ranking the importance of different geographical conditions for managing loblolly pine, we aimed to identify ways to support loblolly growth as a potential feedstock for biofuel generation. We achieved this through collecting survey responses from 43 stakeholders during the 2019 Virginia Forestry Summit. The results showed that the landowner, researcher/educator, and …

Stand Location Variance As An Indicator Of Disturbance Regime In A Monotypic Tsuga Canadensis Forest, Cole J. Doolittle

Honors Program Projects

Disturbance regimes, which are critical components of forest ecosystems, influence forest morphology, biodiversity, and regeneration. The heterogeneity of disturbance regimes are not well understood on small scales. In this study I analyzed tree cores from five sites within a Tsuga canadensis (Eastern hemlock) forest in northern Wisconsin to investigate disturbance regimes through mean growth release criteria. This study investigated the following questions: 1) Are disturbance regimes in T. canadensis stand level or site specific? 2) If disturbances are site specific, is site location an indicator of disturbance regime? 3) Do site characteristics such as density and tree diameter at breast …

Mammals Of The Northern Andes: An Analysis Of Camera Trap Data And Observation In Angochagua, Ecuador, Risa Berman

Independent Study Project (ISP) Collection

The high Andes of Ecuador are home to a diverse community of mammals, many of which are threatened. These include the Andean bear, Andean fox, puma, and mountain tapir. This study used camera traps, direct observation, and indirect observation over three weeks to monitor the wildlife in the mountains of the Parroquia of Angochagua. The five species observed during this period were Andean bear, Andean fox, dog, mountain paca, and mouse. While this short study did not completely survey the mammalian community of the area, it confirmed the presence, diet, sociality, temporal habits, elevational range, and habitat preferences of the …

It's Essential: The Ylang-Ylang Trade On Nosy Be, James Sleigh

Independent Study Project (ISP) Collection

This paper attempts to describe the production and sale of Ylang-Ylang from cultivation of the tree to the export of the flower, and examines the roles and power that each stakeholder has in the value chain. From there, the paper will look at issues associated with the trade; namely of the threat to the terrestrial ecosystem and the profit imbalance in the industry. Finally, the paper turns to potential strategies to resolve the previously stated issues associated with the production and sale of Ylang-Ylang. As a whole I hope that the paper can be seen as a rough survey of …

Competition And Burn Severity Determine Post-Fire Sapling Recovery In A Nationally Protected Boreal Forest Of China: An Analysis From Very High-Resolution Satellite Imagery, Lei Fang, Ellen V. Crocker, Jian Yang, Yan Yan, Yuanzheng Yang, Zhihua Liu

Forestry and Natural Resources Faculty Publications

Anticipating how boreal forest landscapes will change in response to changing fire regime requires disentangling the effects of various spatial controls on the recovery process of tree saplings. Spatially explicit monitoring of post-fire vegetation recovery through moderate resolution Landsat imagery is a popular technique but is filled with ambiguous information due to mixed pixel effects. On the other hand, very-high resolution (VHR) satellite imagery accurately measures crown size of tree saplings but has gained little attention and its utility for estimating leaf area index (LAI, m²/m²) and tree sapling abundance (TSA, seedlings/ha) in post-fire landscape remains …

Potential Economic Impacts Of Allocating More Land For Bioenergy Biomass Production In Virginia, Thomas O. Ochuodho, Janaki R. R. Alavalapati, Pankaj Lal, Domena A. Agyeman, Bernabas Wolde, Pralhad Burli

Forestry and Natural Resources Faculty Publications

The growing attention to renewable energy and rural development has created greater demand for production of biomass feedstock for bioenergy. However, forest growth rates and the amount of land in most existing forests may not be sufficient to sustainably supply the forest biomass required to support existing forest products industries and the expanding bioenergy industry. Additionally, concerns about agricultural land use competition have dampened expansion of biomass production on agricultural land base. One of the ways to meet the growing forest biomass feedstock demand for bioenergy production is by allocating currently marginal non-forested land for growing bioenergy feedstocks. In Virginia, …

Wildfire Alters Spatial Patterns Of Available Soil Nitrogen And Understory Environments In A Valley Boreal Larch Forest, Jianjian Kong, Jian Yang, Bo Liu, Lin Qi

Forestry and Natural Resources Faculty Publications

Wildfire, a primary natural disturbance in many forests, affects soil nutrient availability and spatial distributions of forest plants. However, post-fire changes in soil nutrients and spatial patterns of understory environments at fine scales are poorly understood. Here, we characterized spatial patterns of soil nitrogen availability and site characteristics at a 3-year-post-fire and an unburned site in a valley boreal larch forest. We also examined the relationship between soil nitrogen availability and site characteristics. The results showed that the burned site had higher NO₃⁻ and lower NH₄⁺ than the control. The herb, litter and coarse wood debris …

Dynamics Of Postfire Aboveground Carbon In A Chronosequence Of Chinese Boreal Larch Forests, Yuan Z. Yang, Wen H. Cai, Jian Yang, Megan White, John M. Lhotka

Forestry and Natural Resources Faculty Publications

Boreal forests store a large proportion of the global terrestrial carbon (C), while wildfire plays a crucial role in determining their C storage and dynamics. The aboveground C (AC) pool is an important component of forest C stocks. To quantify the turning point (transforming from C source to C sink) and recovery time of postfire AC, and assess how stand density affects the AC, 175 plots from eight stand age classes were surveyed as a chronosequence in the Great Xing'an Mountains of Northeast China. Linear and nonlinear regression analyses were conducted to describe postfire AC recovery patterns. The results showed …

Understory Community Assembly Following Wildfire In Boreal Forests: Shift From Stochasticity To Competitive Exclusion And Environmental Filtering, Bo Liu, Han Y. H. Chen, Jian Yang

Forestry and Natural Resources Faculty Publications

Understory vegetation accounts for the majority of plant species diversity and serves as a driver of overstory succession and nutrient cycling in boreal forest ecosystems. However, investigations of the underlying assembly processes of understory vegetation associated with stand development following a wildfire disturbance are rare, particularly in Eurasian boreal forests. In this study, we measured the phylogenetic and functional diversity and trait dispersions of understory communities and tested how these patterns changed with stand age in the Great Xing'an Mountains of Northeastern China. Contrary to our expectation, we found that understory functional traits were phylogenetically convergent. We found that random …

Impacts Of Climate Change And Bioenergy Markets On The Profitability Of Slash Pine Pulpwood Production In The Southeastern United States, Andrea Susaeta, Pankaj Lal

Department of Earth and Environmental Studies Faculty Scholarship and Creative Works

In this study, we assessed the impacts of climate change on the production of pulpwood and biomass for bioenergy, and the profitability of slash pine stands in the Southeastern United States. We employed the 3-PG (Physiological Processes Predicting Growth) model to determine the effects of future climates on forest growth and integrated it with a stand-level economic model to determine their impacts on optimal forest management. We found that the average production of pulpwood increased for all sites by 7.5 m³ ha⁻¹ for all climatic scenarios and productivity conditions. In the case of forest biomass for bioenergy, the …

Assessing Ecosystem Services From The Forestry-Based Reclamation Of Surface Mined Areas In The North Fork Of The Kentucky River Watershed, Kumari Gurung, Jian Yang, Lei Fang

Forestry and Natural Resources Faculty Publications

Surface mining is a major driver of land use land cover (LULC) change in many mountainous areas such as the Appalachian region. Typical reclamation practices often result in land cover dominated by grass and shrubs. Assessing ecosystem services that can be obtained from a forest landscape may help policy-makers and other stakeholders fully understand the benefits of forestry-based reclamation (FRA). The objectives of this study are to (1) identify how surface mining and reclamation changed the LULC of a watershed encompassing the north fork of the Kentucky River, (2) assess the biophysical value of four major ecosystem services under the …

Does Environment Filtering Or Seed Limitation Determine Post-Fire Forest Recovery Patterns In Boreal Larch Forests?, Wen H. Cai, Zhihua Liu, Yuan Z. Yang, Jian Yang

Forestry and Natural Resources Faculty Publications

Wildfire is a primary natural disturbance in boreal forests, and post-fire vegetation recovery rate influences carbon, water, and energy exchange between the land and atmosphere in the region. Seed availability and environmental filtering are two important determinants in regulating post-fire vegetation recovery in boreal forests. Quantifying how these determinants change over time is helpful for understanding post-fire forest successional trajectory. Time series of remote sensing data offer considerable potential in monitoring the trajectory of post-fire vegetation recovery dynamics beyond current field surveys about structural attributes, which generally lack a temporal perspective across large burned areas. We used a time series …

Assessment Of The Ponderosa Woodlands In Nebraska's Wildcat Hills: Implications For Juniperus Encroachment And Management, Allie Victoria Schiltmeyer

School of Natural Resources: Dissertations, Theses, and Student Research

Ponderosa pine (Pinus ponderosa) is a dominant tree species across western North America. Its eastern distribution includes three populations in western Nebraska. This study assesses the distribution, structure and age of ponderosa pine woodlands in one of those regions, the Wildcat Hills. The Wildcat Hills have escaped severe wildfires seen in recent decades in other ponderosa pine regions. Nevertheless, the Wildcat Hills woodlands face multiple threats including climate change, wildfire, drought, pine beetles, and invasive species. Key to these threats is the stand structure of pine woodlands, which have increased in density across much of ponderosa pine’s range. …

Restoration Of Legacy Trees As Roosting Habitat For Myotis Bats In Eastern North American Forests, Michael J. Lacki

Forestry and Natural Resources Faculty Publications

Most eastern North American Myotis roost in forests during summer, with species forming maternity populations, or colonies, in cavities or crevices or beneath the bark of trees. In winter, these bats hibernate in caves and are experiencing overwinter mortalities due to infection from the fungus Pseudogymnoascus destructans, which causes white-nose syndrome (WNS). Population recovery of WNS-affected species is constrained by the ability of survivors to locate habitats suitable for rearing pups in summer. Forests in eastern North America have been severely altered by deforestation, land-use change, fragmentation and inadvertent introduction of exotic insect pests, resulting in shifts in tree …

First-Year Vitality Of Reforestation Plantings In Response To Herbivore Exclusion On Reclaimed Appalachian Surface-Mined Land, Zachary J. Hackworth, John M. Lhotka, John J. Cox, Christopher D. Barton, Matthew T. Springer

Forestry and Natural Resources Faculty Publications

Conventional Appalachian surface-mine reclamation techniques repress natural forest regeneration, and tree plantings are often necessary for reforestation. Reclaimed Appalachian surface mines harbor a suite of mammal herbivores that forage on recently planted seedlings. Anecdotal reports across Appalachia have implicated herbivory in the hindrance and failure of reforestation efforts, yet empirical evaluation of herbivory impacts on planted seedling vitality in this region remains relatively uninitiated. First growing-season survival, height growth, and mammal herbivory damage of black locust (Robinia pseudoacacia L.), shortleaf pine (Pinus echinata Mill.), and white oak (Quercus alba L.) are presented in response to varying intensities …

Phytophthora Cinnamomi Colonized Reclaimed Surface Mined Sites In Eastern Kentucky: Implications For The Restoration Of Susceptible Species, Kenton L. Sena, Kevin M. Yeager, Tyler J. Dreaden, Christopher D. Barton

Forestry and Natural Resources Faculty Publications

Appalachian forests are threatened by a number of factors, especially introduced pests and pathogens. Among these is Phytophthora cinnamomi, a soil-borne oomycete pathogen known to cause root rot in American chestnut, shortleaf pine, and other native tree species. This study was initiated to characterize the incidence of P. cinnamomi on surface mined lands in eastern Kentucky, USA, representing a range of time since reclamation (10, 12, 15, and 20 years since reclamation). Incidence of P. cinnamomi was correlated to soil properties including overall soil development, as indicated by a variety of measured soil physical and chemical parameters, especially the …