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Full-Text Articles in Forest Sciences

Human Dimensions Of Woody Encroachment Management In Nebraska, Emily Rowen Dec 2023

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 …


Systematic Review: Effect Of Cover Crop On Working Farm, Noella A. Bahatsi Mar 2023

Systematic Review: Effect Of Cover Crop On Working Farm, Noella A. Bahatsi

Honors Theses

On-farm research is when research techniques such as randomized, replicated treatments strips and large-scale techniques are used on actual farms or ranches. Due to a great deal of interest and curiosity among farmers and researchers who wish to make their farming methods more profitable, efficient, and/or sustainable, this type of research has been conducted more frequently each year. On-farm research has contributed to economic growth and the transfer of knowledge to farmers because of fresh discoveries and upgraded technology (Lacoste et al., 2022). This is also where farmers collaborate with researchers to test new management practices and technologies providing unbiased …


Assessing Functional Biodiversity For The Future Of Plants, Planet, And People, Ali Loker Mar 2023

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 …


Impact Of Eastern Redcedar Encroachment On Water Resources In The Nebraska Sandhills, Yaser Kishawi, Aaron R. Mittelstet, Troy E. Gilmore, Dirac Twidwell, Tirthankar Roy, Nawaraj Shrestha Jan 2023

Impact Of Eastern Redcedar Encroachment On Water Resources In The Nebraska Sandhills, Yaser Kishawi, Aaron R. Mittelstet, Troy E. Gilmore, Dirac Twidwell, Tirthankar Roy, Nawaraj Shrestha

Department of Biological Systems Engineering: Papers and Publications

Worldwide, tree or shrub dominated woodlands have encroached into herbaceous dominated grasslands. While very few studies have evaluated the impact of Eastern Redcedar (redcedar) encroachment on the water budget, none have analyzed the impact on water quality. In this study, we evaluated the impact of redcedar encroachment on the water budget in the Nebraska Sand Hills and how the decreased streamflow would increase nitrate and atrazine concentrations in the Platte River. We calibrated a Soil and Water Assessment Tool (SWAT model) for streamflow, recharge, and evapotranspiration. Using a moving window with a dilate morphological filter, encroachment scenarios of 11.9%, 16.1%, …


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 Feb 2022

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 …


Seed Rain–Successional Feedbacks In Wet Tropical Forests, Nohemi Huanca Nuñez, Robin L. Chazdon, Sabrina E. Russo Apr 2021

Seed Rain–Successional Feedbacks In Wet Tropical Forests, Nohemi Huanca Nuñez, Robin L. Chazdon, Sabrina E. Russo

School of Biological Sciences: Faculty Publications

Abstract

Tropical forest regeneration after abandonment of former agricultural land depends critically on the input of tree seeds, yet seed dispersal is increasingly disrupted in contemporary human-modified landscapes. Here, we introduce the concept of seed rain–successional feedbacks as a deterministic process in which seed rain is shaped by successional dynamics internal to a forest site and that acts to reinforce priority effects. We used a combination of time series and chronosequence approaches to investigate how the quantity and taxonomic and functional composition of seed rain change during succession and to evaluate the strength of seed rain–successional feedbacks, relative to other …


Extreme Fire As A Management Tool To Combat Regime Shifts In The Range Of The Endangered American Burying Beetle, Alison K. Ludwig, Daniel R. Uden, Dirac Twidwell Apr 2020

Extreme Fire As A Management Tool To Combat Regime Shifts In The Range Of The Endangered American Burying Beetle, Alison K. Ludwig, Daniel R. Uden, Dirac Twidwell

Department of Agronomy and Horticulture: Dissertations, Theses, and Student Research

This study is focused on the population of federally-endangered American burying beetles in south-central Nebraska. It is focused on changes in land cover over time and at several levels of spatial scale, and how management efforts are impacting both the beetle and a changing landscape. Our findings are applicable to a large portion of the Great Plains, which is undergoing the same shift from grassland to woodland, and to areas where the beetle is still found.


Draft Genome Assembly Of Passalora Sequoiae A Needle Blight Pathogen On Leyland Cypress, Warren E. Copes, Jorge Ibarra Caballero, Ebrahiem Babiker, Jane E. Stewart, Valerie A. Orner, Alan S. Windham, Renee Arias Jan 2020

Draft Genome Assembly Of Passalora Sequoiae A Needle Blight Pathogen On Leyland Cypress, Warren E. Copes, Jorge Ibarra Caballero, Ebrahiem Babiker, Jane E. Stewart, Valerie A. Orner, Alan S. Windham, Renee Arias

United States Department of Agriculture-Agricultural Research Service / University of Nebraska-Lincoln: Faculty Publications

Objective: Passalora sequoiae (family Mycosphaerellaceae) causes a twig blight on Leyland cypress that requires numerous fungicide applications annually to minimize economic losses for ornamental plant nursery and Christmas tree producers. The objective was to generate a high-quality draft assembly of the genome of P. sequoiae as a resource for primer development to investigate genotype diversity. Data description: We report here the genome sequence of P. sequoiae 9LC2 that was isolated from Leyland cypress ‘Leighton Green’ in 2017 in southern Mississippi, USA. The draft genome was obtained using Pacific Biosciences (PacBio) SMRT and Illumina HiSeq 2500 sequencing. Illumina reads were mapped …


Lithological Constraints On Resource Economies Shape The Mycorrhizal Composition Of A Bornean Rain Forest, Monique Weemstra, Kabir G. Peay, Stuart J. Davies, Mohizah Mohamad, Akira Itoh, Sylvester Tan, Sabrina E. Russo Jan 2020

Lithological Constraints On Resource Economies Shape The Mycorrhizal Composition Of A Bornean Rain Forest, Monique Weemstra, Kabir G. Peay, Stuart J. Davies, Mohizah Mohamad, Akira Itoh, Sylvester Tan, Sabrina E. Russo

School of Biological Sciences: Faculty Publications

• Arbuscular mycorrhizal fungi (AMF) and ectomycorrhizal fungi (EMF) produce contrasting plant–soil feedbacks, but how these feedbacks are constrained by lithology is poorly understood.

• We investigated the hypothesis that lithological drivers of soil fertility filter plant resource economic strategies in ways that influence the relative fitness of trees with AMF or EMF symbioses in a Bornean rain forest containing species with both mycorrhizal strategies.

• Using forest inventory data on 1245 tree species, we found that although AMF-hosting trees had greater relative dominance on all soil types, with declining lithological soil fertility EMF-hosting trees became more dominant. Data on …


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 Jul 2019

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

USDA Forest Service / UNL 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 …


Introduction To Sorghum Paper Production, Zachary Christman May 2019

Introduction To Sorghum Paper Production, Zachary Christman

Department of Agronomy and Horticulture: Dissertations, Theses, and Student Research

Sorghum is a tall grass used for many commercial products such as fodder and syrup. The 10 to 15 feet stalk of the plant has lower lignin than wood and provides a fiber length of 2.31 mm in the outer covering and 1.38 mm for the leaf. Sorghum fiber makes a high quality, strong paper suitable for printing, packaging and paperboard.


Habitat Characteristics And Selection By Ornate Box Turtles In The Sandhills Of South Dakota, Daniel W, Uresk, Alessandra Higa Apr 2019

Habitat Characteristics And Selection By Ornate Box Turtles In The Sandhills Of South Dakota, Daniel W, Uresk, Alessandra Higa

USDA Forest Service / UNL Faculty Publications

The ornate box turtle (Terrapene ornata Agassiz) is a species of greatest conservation need in South Dakota. Habitat loss through agricultural development and fragmentation is the main threat to the species throughout its range, which extends from Wisconsin and northern Indiana through the central Great Plains, and from southern South Dakota to Arizona, northern Mexico, and the Gulf Coast of Texas. The objectives of this study were to determine the ornate box turtle’s preferred vegetation characteristics (microhabitat) compared to the available habitat (macrohabitat) on the Pine Ridge Reservation, South Dakota Sandhills region, during 2010–2011. In both years, using a modified …


Hillslope Hydrology In Global Change Research And Earth System Modeling, Y. Fan, M. Clark, D. M. Lawrence, S. Swenson, L.E. Band, S. L. Brantley, P. D. Brooks, W. E. Dietrich, A. Flores, G. Grant, J.W. Kirchner, D. S. Mackay, J. J. Mcdonnell, P. C. D. Milly, P. L. Sullivan, C. Tague, H. Ajami, N. Chaney, A. Hartmann, P. Hazenberg, J. Mcnamara, J. Pelletier, J. Perket, E. Rouholahnejad‐Freund, T. Wagener, X. Zeng, E. Beighley, J. Buzan, M. Huang, B. Livneh, B. P. Mohanty, B. Nijssen, M. Safeeq, C. Shen, W. Van Verseveld, J. Volk, D. Yamazaki Feb 2019

Hillslope Hydrology In Global Change Research And Earth System Modeling, Y. Fan, M. Clark, D. M. Lawrence, S. Swenson, L.E. Band, S. L. Brantley, P. D. Brooks, W. E. Dietrich, A. Flores, G. Grant, J.W. Kirchner, D. S. Mackay, J. J. Mcdonnell, P. C. D. Milly, P. L. Sullivan, C. Tague, H. Ajami, N. Chaney, A. Hartmann, P. Hazenberg, J. Mcnamara, J. Pelletier, J. Perket, E. Rouholahnejad‐Freund, T. Wagener, X. Zeng, E. Beighley, J. Buzan, M. Huang, B. Livneh, B. P. Mohanty, B. Nijssen, M. Safeeq, C. Shen, W. Van Verseveld, J. Volk, D. Yamazaki

USDA Forest Service / UNL Faculty Publications

Earth System Models (ESMs) are essential tools for understanding and predicting global change, but they cannot explicitly resolve hillslope‐scale terrain structures that fundamentally organize water, energy, and biogeochemical stores and fluxes at subgrid scales. Here we bring together hydrologists, Critical Zone scientists, and ESM developers, to explore how hillslope structures may modulate ESM grid‐level water, energy, and biogeochemical fluxes. In contrast to the one‐dimensional (1‐D), 2‐ to 3‐mdeep, and free‐draining soil hydrology in most ESM land models, we hypothesize that 3‐D, lateral ridge‐to‐valley flow through shallow and deep paths and insolation contrasts between sunny and shady slopes are the top …


Testing The Competition-Colonization Trade-Off And Its Correlations With Functional Trait Variations Among Subtropical Tree Species, Yue Bin, Guojun Lin, Sabrina E. Russo, Zhongliang Huang, Yong Shen, Honglin Cao, Juyu Lian, Wanhui Ye Jan 2019

Testing The Competition-Colonization Trade-Off And Its Correlations With Functional Trait Variations Among Subtropical Tree Species, Yue Bin, Guojun Lin, Sabrina E. Russo, Zhongliang Huang, Yong Shen, Honglin Cao, Juyu Lian, Wanhui Ye

School of Biological Sciences: Faculty Publications

The competition-colonization trade-off, by which species can partition spatial niches, is a potentially important mechanism allowing the maintenance of species diversity in plant communities. We examined whether there was evidence for this trade-off among tree species in a subtropical forest and how it correlated with eight functional traits. We developed and estimated a metric for colonization ability that incorporates both fecundity and seed dispersal based on seed trap data and the sizes and distributions of adult trees. Competitive ability was estimated as survival probability under high crowding conditions based on neighborhood models. Although we found no significant relationship between colonization …


Biological Aspects Of Mountain Pine Beetle In Lodgepole Pine Stands Of Different Densities In Colorado, Usa, Jose Negron Dec 2018

Biological Aspects Of Mountain Pine Beetle In Lodgepole Pine Stands Of Different Densities In Colorado, Usa, Jose Negron

USDA Forest Service / UNL Faculty Publications

Research Highlights: The biology of mountain pine beetle (MPB), Dendroctonus ponderosae Hopkins, in Colorado’s lodgepole pine forests exhibits similarities and differences to other parts of its range. Brood emergence was not influenced by stand density nor related to tree diameter. The probability of individual tree attack is influenced by stocking and tree size. Findings have implications for understanding MPB as a disturbance agent and for developing management strategies. Background and Objectives: MPB causes extensive tree mortality of lodgepole pine, Pinus contorta Douglas ex Loudon, across the western US and Canada and is probably the most studied bark beetle in North …


Improving Ecological Restoration To Curb Biotic Invasion—A Practical Guide, Qinfeng Guo, Dale G. Brockway, Diane L. Larson, Deli Wang, Hai Ren Nov 2018

Improving Ecological Restoration To Curb Biotic Invasion—A Practical Guide, Qinfeng Guo, Dale G. Brockway, Diane L. Larson, Deli Wang, Hai Ren

USDA Forest Service / UNL Faculty Publications

Common practices for invasive species control and management include physical, chemical, and biological approaches. The first two approaches have clear limitations and may lead to unintended (negative) consequences, unless carefully planned and implemented. For example, physical removal rarely completely eradicates the targeted invasive species and can cause disturbances that facilitate new invasions by nonnative species from nearby habitats. Chemical treatments can harm native, and especially rare, species through unanticipated side effects. Biological methods may be classified as biocontrol and the ecological approach. Similar to physical and chemical methods, biocontrol also has limitations and sometimes leads to unintended consequences. Therefore, a …


Short Communications: First Tracking Of Individual American Robins (Turdus Migratorius) Across Seasons, Alex E. Jahn, Susannah B. Lerman, Laura M. Phillips, Thomas B. Ryder, Emily J. Williams Sep 2018

Short Communications: First Tracking Of Individual American Robins (Turdus Migratorius) Across Seasons, Alex E. Jahn, Susannah B. Lerman, Laura M. Phillips, Thomas B. Ryder, Emily J. Williams

USDA Forest Service / UNL Faculty Publications

The American Robin (Turdus migratorius) is one of the most widespread, common bird species in North America; yet, very little is known about its migratory connectivity, migration timing, and migratory routes. Using archival GPS tags, we tracked the movements of 7 individual robins from 3 breeding populations in the United States. Four robins captured in Denali National Park and Preserve, Alaska, overwintered in Texas, Nebraska, Oklahoma, and Montana, up to 4,500 km from the capture location. One robin captured in Amherst, Massachusetts, overwintered in South Carolina 1,210 km from the capture location, whereas 2 robins captured in Washington, D.C., spent …


Tamm Review: Reforestation For Resilience In Dry Western U.S. Forests, Malcolm P. North, Jens T. Stevens, David F. Greene, Michelle Coppoletta, Eric E. Knapp, Andrew M. Latimer, Christina M. Restaino, Ryan E. Tompkins, Kevin R. Welch, Rob A. York, Derek J.N. Young, Jodi N. Axelson, Tom N. Buckley, Becky L. Estes, Rachel N. Hager, Jonathan W. Long, Marc D. Meyer, Steven M. Ostoja, Hugh D. Safford, Kristen L. Shive, Carmen L. Tubbesing, Dana Walsh, Chhaya M. Werner, Peter Wyrsch, Heather Vice Sep 2018

Tamm Review: Reforestation For Resilience In Dry Western U.S. Forests, Malcolm P. North, Jens T. Stevens, David F. Greene, Michelle Coppoletta, Eric E. Knapp, Andrew M. Latimer, Christina M. Restaino, Ryan E. Tompkins, Kevin R. Welch, Rob A. York, Derek J.N. Young, Jodi N. Axelson, Tom N. Buckley, Becky L. Estes, Rachel N. Hager, Jonathan W. Long, Marc D. Meyer, Steven M. Ostoja, Hugh D. Safford, Kristen L. Shive, Carmen L. Tubbesing, Dana Walsh, Chhaya M. Werner, Peter Wyrsch, Heather Vice

USDA Forest Service / UNL Faculty Publications

The increasing frequency and severity of fire and drought events have negatively impacted the capacity and success of reforestation efforts in many dry, western U.S. forests. Challenges to reforestation include the cost and safety concerns of replanting large areas of standing dead trees, and high seedling and sapling mortality rates due to water stress, competing vegetation, and repeat fires that burn young plantations. Standard reforestation practices have emphasized establishing dense conifer cover with gridded planting, sometimes called 'pines in lines', followed by shrub control and pre-commercial thinning. Resources for such intensive management are increasingly limited, reducing the capacity for young …


On-Road Emissions Of Ammonia: An Underappreciated Source Of Atmospheric Nitrogen Deposition, Mark E. Fenn, Andrzej Bytnerowicz, Susan L. Schilling, Dena M. Vallano, Erika S. Zavaleta, Stuart B. Weiss, Connor Morozumi, Linda H. Geiser, Kenneth Hanks Jan 2018

On-Road Emissions Of Ammonia: An Underappreciated Source Of Atmospheric Nitrogen Deposition, Mark E. Fenn, Andrzej Bytnerowicz, Susan L. Schilling, Dena M. Vallano, Erika S. Zavaleta, Stuart B. Weiss, Connor Morozumi, Linda H. Geiser, Kenneth Hanks

USDA Forest Service / UNL Faculty Publications

We provide updated spatial distribution and inventory data for on-road NH3 emissions for the continental United States (U.S.) On-road NH3 emissions were determined from on-road CO2 emissions data and empirical NH3:CO2 vehicle emissions ratios. Emissions of NH3 from on-road sources in urbanized regions are typically 0.1– 1.3 t km−2 yr−1 while NH3 emissions in agricultural regions generally range from 0.4–5.5 t km−2 yr−1, with a few hot spots as high as 5.5–11.2 t km−2 yr−1. Counties with higher vehicle NH3 emissions than from agriculture …


Ecological-Economic Assessment Of The Effects Of Freshwater Flow In The Florida Everglades On Recreational Fisheries, Christina Estela Brown, Mahadev G. Bhat, Jennifer S. Rehage, Ali Mirchi, Ross Boucek, Victor Engel, Jerald S. Ault, Pallab Mozumder, David Watkins, Michael Sukop Jan 2018

Ecological-Economic Assessment Of The Effects Of Freshwater Flow In The Florida Everglades On Recreational Fisheries, Christina Estela Brown, Mahadev G. Bhat, Jennifer S. Rehage, Ali Mirchi, Ross Boucek, Victor Engel, Jerald S. Ault, Pallab Mozumder, David Watkins, Michael Sukop

USDA Forest Service / UNL Faculty Publications

This research develops an integrated methodology to determine the economic value to anglers of recreational fishery ecosystem services in Everglades National Park that could result from different water management scenarios. The study first used bio-hydrological models to link managed freshwater inflows to indicators of fishery productivity and ecosystem health, then link those models to anglers' willingness-to-pay for various attributes of the recreational fishing experience and monthly fishing effort. This approach allowed us to estimate the foregone economic benefits of failing to meet monthly freshwater delivery targets. The study found that the managed freshwater delivery to the Park had declined substantially …


Variation In Density Dependent Seedling Survival Across Forests Of Different Successional Age And Hunting Protection Status, Nohemi Huanca-Nunez May 2017

Variation In Density Dependent Seedling Survival Across Forests Of Different Successional Age And Hunting Protection Status, Nohemi Huanca-Nunez

School of Biological Sciences: Dissertations, Theses, and Student Research

Over 50% of the original extent of tropical forests has been cleared. Restoration of secondary forests is important for maintaining the ecosystem services that mature tropical forests provide. Density dependence (DD) is thought to be a major mechanism for shaping forest community structure and may cause reduced spatial aggregation among individuals of the same species, allowing for maintenance of diversity. While much research has focused on DD in mature tropical forests, few studies have examined how DD may influence community structure in secondary forests, many of which are also exposed to hunting. There are several important agents of negative and …


Assessing Responses Of Betula Papyrifera (Paper Birch) To Climate Variability In A Remnant Population Along The Niobrara River In Nebraska Through Dendroecological And Remote Sensing Techniques, Evan Bumann Jan 2017

Assessing Responses Of Betula Papyrifera (Paper Birch) To Climate Variability In A Remnant Population Along The Niobrara River In Nebraska Through Dendroecological And Remote Sensing Techniques, Evan Bumann

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

Remnant populations of the boreal species Betula papyrifera, found along north-facing canyons and river banks of the Niobrara River Valley in north-central Nebraska, represent one of the southernmost distributions of the species in North America. Although, the species has persisted in the Great Plains after the Wisconsin Glaciation due to the local topography and microclimatic conditions, canopy dieback has been reported in recent years, which is believed to be attributed to temperature change. Therefore, the goals of this research are to: 1) use dendroecological techniques, or the study of tree rings to assess the responses B. papyrifera to intra- and …


Native And Agricultural Forests At Risk To A Changing Climate In The Northern Plains, Linda A. Joyce, Gary Bentrup, Antony S. Cheng, Peter Kolb, Michele Schoeneberger, Justin Derner Jan 2017

Native And Agricultural Forests At Risk To A Changing Climate In The Northern Plains, Linda A. Joyce, Gary Bentrup, Antony S. Cheng, Peter Kolb, Michele Schoeneberger, Justin Derner

USDA Forest Service / UNL Faculty Publications

Native and agricultural forests in the Northern Plains provide ecosystem services that benefit human society—diversified agricultural systems, forest-based products, and rural vitality. The impacts of recent trends in temperature and disturbances are impairing the delivery of these services. Climate change projections identify future stressors of greater impact, placing at risk crops, soils, livestock, biodiversity, and agricultural and forest-based livelihoods. While these native and agricultural forests are also a viable option for providing mitigation and adaptation services to the Northern Plains, they themselves must be managed in terms of climate change risks. Because agricultural forests are planted systems, the primary approaches …


Shape Indexes For Semi-Automated Detection Of Windbreaks In Thematic Tree Cover Maps From The Central United States, Greg C. Liknes, Dacia M. Meneguzzo, Todd A. Kellerman Jan 2017

Shape Indexes For Semi-Automated Detection Of Windbreaks In Thematic Tree Cover Maps From The Central United States, Greg C. Liknes, Dacia M. Meneguzzo, Todd A. Kellerman

USDA Forest Service / UNL Faculty Publications

Windbreaks are an important ecological resource across the large expanse of agricultural land in the central United States and are often planted in straight-line or L-shaped configurations to serve specific functions. As high-resolution (i.e., <5 m) land cover data sets become more available for these areas, semi-or fully-automated methods for distinguishing windbreaks from other patches of trees are needed for use with thematic raster data sets. To address this need, we created three shape indexes: a morphology-based index that we have named the Straight and Narrow Feature Index (SNFI), a windbreak sinuosity index, and an area index indicating the occupied fractional area of a bounding box. The indexes were tested in two study areas: (1) a riparian area dominated by sinuous bands of trees but mixed with row crop agriculture and (2) an agricultural area with a mix of straight-line and L-shaped windbreaks. In the riparian area, a Kruskall–Wallis rank sum test indicated class differences for all three indexes, and pairwise comparisons indicate windbreaks and riparian trees are separable using any of the three indexes. SNFI also produced significant differences between windbreaks oriented in different directions (east–west vs. north–south). In the agricultural area, the Kruskall–Wallis rank sum test indicated differences between classes for all three indexes, and pairwise comparisons show that all class pairs have significant differences for at least one index, with the exception of L-shaped windbreaks vs. non-windbreak tree patches. We also used classification trees to objectively assign representative samples of tree patches to classes using both single indexes and multiple indexes. Classes were correctly assigned for more than 90% of the samples in both the riparian and agricultural study areas. In the riparian area, combining indexes did not improve accuracy compared to using SNFI alone, whereas in the agricultural area, combining the three indexes produced the best result. Thematic data sets derived from high-resolution imagery are becoming more available, and extracting useful information can be a challenge, partly due to the large amount of data to assess. Calculating the three shape indexes presented can assist with efficient identification of candidate windbreaks and as such, hold good promise for value-added analysis of tree function in the central United States.


Are Northeastern U.S. Forests Vulnerable To Extreme Drought?, Adam P. Coble, Matthew A. Vadeboncoeur, Z. Carter Berry, Katie A. Jennings, Cameron D. Mcintire, John L. Campbell, Lindsey E. Rustad, Pamela H. Temper, Heidi Asbjornsen Jan 2017

Are Northeastern U.S. Forests Vulnerable To Extreme Drought?, Adam P. Coble, Matthew A. Vadeboncoeur, Z. Carter Berry, Katie A. Jennings, Cameron D. Mcintire, John L. Campbell, Lindsey E. Rustad, Pamela H. Temper, Heidi Asbjornsen

USDA Forest Service / UNL Faculty Publications

In the Northeastern U.S., drought is expected to increase in frequency over the next century, and therefore, the responses of trees to drought are important to understand. There is recent debate about whether land-use change or moisture availability is the primary driver of changes in forest species composition in this region. Some argue that fire suppression from the early twentieth century to present has resulted in an increase in shade-tolerant and pyrophobic tree species that are drought intolerant, while others suggest precipitation variability as a major driver of species composition. From this debate, an emerging hypothesis is that mesophication and …


An Artificial Neural Network For Real-Time Hardwood Lumber Grading, Edward Thomas Jan 2017

An Artificial Neural Network For Real-Time Hardwood Lumber Grading, Edward Thomas

USDA Forest Service / UNL Faculty Publications

Computerized grading of hardwood lumber according to NHLA rules would permit fast assessment of sawn lumber and the evaluation of potential edging and trimming operations to improve lumber value. More importantly, to enable optimization of the hardwood lumber sawing process, a fast means of evaluating the potential value of boards before they are sawn is necessary. As log and lumber scanning systems become prevalent and common, these needs become more pressing. From an automation perspective, the NHLA lumber grades are difficult to implement efficiently in a computer program. Exhaustive approaches that examine every potential cutting size and combination to determine …


Interactions Between White-Tailed Deer Density And The Composition Of Forest Understories In The Northern United States, Matthew B. Russell, Christopher W. Woodall, Kevin M. Potter, Brian F. Walters, Grant M. Domke, Christopher M. Oswalt Jan 2017

Interactions Between White-Tailed Deer Density And The Composition Of Forest Understories In The Northern United States, Matthew B. Russell, Christopher W. Woodall, Kevin M. Potter, Brian F. Walters, Grant M. Domke, Christopher M. Oswalt

USDA Forest Service / UNL Faculty Publications

Forest understories across the northern United States (US) are a complex of tree seedlings, endemic forbs, herbs, shrubs, and introduced plant species within a forest structure defined by tree and forest floor attributes. The substantial increase in white-tailed deer (Odocoileus virginianus Zimmerman) populations over the past decades has resulted in heavy browse pressure in many of these forests. To gain an objective assessment of the role of deer in forested ecosystems, a region-wide forest inventory across the northern US was examined in concert with white-tailed deer density information compiled at broad scales. Results indicate that deer density may be …


Residential Building Energy Conservation And Avoided Power Plant Emissions By Urban And Community Trees In The United States, David J. Nowak, Nathaniel Appleton, Alexis Ellis, Eric Greenfield Jan 2017

Residential Building Energy Conservation And Avoided Power Plant Emissions By Urban And Community Trees In The United States, David J. Nowak, Nathaniel Appleton, Alexis Ellis, Eric Greenfield

USDA Forest Service / UNL Faculty Publications

Urban trees and forests alter building energy use and associated emissions from power plants by shading buildings, cooling air temperatures and altering wind speeds around buildings. Field data on urban trees were combined with local urban/community tree and land cover maps, modeling of tree effects on building energy use and pollutant emissions, and state energy and pollutant costs to estimate tree effects on building energy use and associated pollutant emissions at the state to national level in the conterminous United States. Results reveal that trees and forests in urban/community areas in the conterminous United States annually reduce electricity use by …


Quantifying Fish Habitat Associated With Stream Simulation Design Culverts In Northern Wisconsin, A. Timm, D. Higgins, J. Stanovick, R. Kolka, S. Eggert Jan 2017

Quantifying Fish Habitat Associated With Stream Simulation Design Culverts In Northern Wisconsin, A. Timm, D. Higgins, J. Stanovick, R. Kolka, S. Eggert

USDA Forest Service / UNL Faculty Publications

This study investigated the effects of culvert replacement design on fish habitat and fish weight by comparing substrate diversity and weight at three stream simulation (SS)-design and three bankfull and backwater (BB)-design sites on the Chequamegon-Nicolet National Forest, Wisconsin. Stream channel cross-sections, Wolman substrate particle counts, and single-pass backpack electro-fishing survey data were used to quantify fish habitat and fish weight in 50-m upstream and downstream sample reaches at each site. We applied generalized linear mixed models to test the hypothesis that substrate size and fish weight did not differ according to stream-crossing design type (SS or BB) and location …


Invasibility Of Three Major Non-Native Invasive Shrubs And Associated Factors In Upper Midwest U.S. Forest Lands, W. Keith Moser, Zhaofei Fan, Mark H. Hansen, Michael K. Crosby, Shirley X. Fan Jan 2016

Invasibility Of Three Major Non-Native Invasive Shrubs And Associated Factors In Upper Midwest U.S. Forest Lands, W. Keith Moser, Zhaofei Fan, Mark H. Hansen, Michael K. Crosby, Shirley X. Fan

USDA Forest Service / UNL Faculty Publications

We used non-native invasive plant data from the US Forest Service’s Forest Inventory and Analysis (FIA) program, spatial statistical methods, and the space (cover class)-for-time approach to quantify the invasion potential and success (‘‘invasibility”) of three major invasive shrubs (multiflora rose, non-native bush honeysuckles, and common buckthorn) in broadly classified forest-type groups in seven Upper Midwest states. Smoothed maps of presence and cover percent showed a strong clustering pattern for all three invasive shrubs despite their different ranges. The species are clustered around major cities or urban areas (e.g., Chicago, Illinois, and Des Moines, Iowa), indicating the potential role humans …