Ecology and Evolutionary Biology Commons^™

Molecular Differentiation Of Astragalus Species And Varieties From The Western United States: The Chloroplast Dna Bridge Between Evolution And Molecular Systematics, Marwa Neyaz, Daniel Cook, Rebecca Creamer

Poisonous Plant Research (PPR)

Locoweeds are the most widespread poisonous plant problem in the world and have been reported in the Western United States since the 1800s, causing tremendous losses in livestock. Consumption of locoweeds by grazing animals stimulates the neurological disease, locoism, characterized by weight loss, ataxia, and lack of muscular coordination. The name locoweed is used for Astragalus and Oxytropis species known to contain swainsonine, the toxic principle produced by the plant endophytic fungus Undifilum. Astragalus includes 2,500-3,000 species and many varieties that have almost identical morphological characteristics that overlap among species, leading to improper identification. Therefore, the aim of this study …

Genetic Parameters Of Growth And Adaptive Traits In Aspen (Populus Tremuloides): Implications For Tree Breeding In A Warming World, Chen Ding, Andreas Hamann, Rong-Cai Yang, Jean S. Brouard

Aspen Bibliography

Aspen (Populus tremuloides Michx) is a widespread commercial forest tree of high economic importance in western Canada and has been subject to tree improvement efforts over the past two decades. Such improvement programs rely on accurate estimates of the genetic gain in growth traits and correlated response in adaptive traits that are important for forest health. Here, we estimated genetic parameters in 10 progeny trials containing >30,000 trees with pedigree structures based on a partial factorial mating design that includes 60 half-sibs, 100 full-sib families and 1,400 clonally replicated genotypes. Estimated narrow-sense and broad-sense heritabilities were low for height …

Eelgrass Health Survey And Results, Nicholas B. Anderson, Catherine M. Ashcraft, Dante D. Torio, Frederick T. Short

Natural Resources & the Environment

Researchers at the University of New Hampshire designed, tested, and conducted an eelgrass health survey. The primary goal of the survey was to collect health ratings from respondents who had viewed pre-selected images of eelgrass representing a wide range of health conditions. Survey results were used as a calibration and validation to a novel eelgrass health index developed using video-monitoring. Two secondary goals of this this survey were the identification of plant-specific and environmental characteristics important to respondents and the introduction of the new eelgrass health index. This published dataset includes de-identified survey respondent background and demographic data, the survey …

Availability Of Soil Mutualists May Not Limit Non‐Native Acacia Invasion But Could Increase Their Impact On Native Soil Communities, Elizabeth M. Wandrag, Christina Birnbaum, Metha M. Klock, Luke G. Barrett, Peter H. Thrall

Faculty Publications, Environmental Studies

1. The availability of compatible mutualistic soil microbes could influence the invasion success of non-native plant species. Specifically, there may be spatial variation in the distribution of compatible microbes, and species-specific variation in plant host ability to associate with available microbes. Although either or both factors could promote or limit invasion, the scale over which most studies are conducted makes it difficult to examine these two possibilities simultaneously. However, this is critical to identifying a role of soil microbes in invasion.
2. A series of recent research projects focused on interactions between Australian Acacia and nitrogen-fixing bacteria (rhizobia) at multiple spatial scales, …

Contrasting Root System Structure And Belowground Interactions Between Black Spruce (Picea Mariana (Mill.) B.S.P) And Trembling Aspen (Populus Tremuloides Michx) In Boreal Mixedwoods Of Eastern Canada, Claudele Ghotsa Mekontchou, Daniel Houle, Yves Bergeron, Igor Drobyshev

Aspen Bibliography

This study explored the underground interactions between black spruce and trembling aspen in pure and mixed stands to understand how their soil resource use help these species coexist in the boreal mixedwoods of Western Quebec. We analyzed species-specific fine root foraging strategies (root biomass and root tissue density) along three soil layers (organic, top 0–15 cm, and bottom 15–30 cm mineral soil), using 180 soil cores. We collected cores in three sites, each containing three 20 × 50 m2 plots of pure spruce, pure aspen, and mixed spruce and aspen stands. Spruce had a shallow rooting, whereas aspen had a …

Subalpine Forest Tree Seedling Response To Drought, Alex Goke

Electronic Theses and Dissertations

Knowledge of tree species’ ability to tolerate drought is necessary to anticipate future forest dynamics with climate change, especially at the seedling stage given their role in shaping forest structure. We used precipitation reduction shelters to mimic drought for subalpine conifer seedlings (A. lasiocarpa and P. engelmannii) in the Rocky Mountains and compared survivorship and morphological and physiological responses to assess relative degrees of drought tolerance. We detected no significant investment in morphological tolerance traits (e.g. root biomass, leaf:stem area ratio) but substantial reductions in net photosynthesis. While shading partially ameliorated drought effects when precipitation reduction was moderate, …

Integration Of Crop-Livestock Systems: An Opportunity Toprotect Grasslands From Conversion To Cropland In The Us Great Plains, Alexander J. Smart, Daren Redfearn, Robert Mitchell, Tong Wang, Cody Zilverberg, Pete J. Bauman, Justin D. Derner, Julie Walker, Cody Wright

Native Plant Focused Publications

The Great Plains is a mixture of cropland and grassland mainly used for agricultural purposes, with grasslands under continual threat of conversion to cropland. Agriculturists are advocating for the integration of crop-livestock systems (ICLS) to recouple nutrient cycles, improve biodiversity, and increase resilience of agricultural operations. We address the benefits of ICLS in the Great Plains, contending that focus on improving soil health and financial stability of agricultural operations should reduce the conversion of grasslands to cropland. Using US Department of Agriculture National Agricultural Statistics Service Census of Agriculture survey data from the 1925 to 2017 category “cropland used only …

Influence Of Burner Position On Temperature Distribution In Soybean Flaming, Miloš Miloš Rajkovic, Goran Malidža, Strahinja Stepanovic, Marko Kostic, Kristina Petrovic

West Central Research and Extension Center, North Platte

The main objective of this study was to identify optimal burner orientation for a newly designed flame cultivator by quantifying the flame temperature distributions of cross, back, and parallel position of burners at different heights of the soybean canopy (distance from the soil surface). Flame temperatures were measured within-row for three burner orientations at seven propane doses (20–100 kg/ha) and eight different canopy heights (0–18 cm above soil surface). Soybean plants in V3 growth stage were flamed with the same doses and burner orientations, and 28 days after treatment (DAT) crop injury (0%–100%), plant height (cm), dry matter (g) and …

Weed Science Research Summary 2020

West Central Research and Extension Center, North Platte

Contents

Assessment of Industrial Hemp Susceptibility to Off-target Movement of Commonly Applied Corn and Soybean Postemergence Herbicides; Milos Zaric, Bruno Canella Vieira, Marija Savic, Barbara Vukoja, Guilherme Sousa Alves, Greg R. Kruger

Effects of Drift-reducing Nozzles and Adjuvants on Dicamba Efficacy; Milos Zaric, Kasey P. Schroeder, Bruno Canella Vieira, Guilherme Sousa Alves, Jesaelen Gizotti de Moraes, Jeffrey A. Golus, Greg R. Kruger

Dicamba Simulated Tank-contamination in Common Postemergence Non-dicamba-tolerant Soybean Herbicide Programs; Milos Zaric, Guilherme Sousa Alves, Bruno Canella Vieira, Jeffrey A. Golus, Greg R. Kruger

Air Induction nozzles pattern distribution influenced by work pressure and boom height; Antonio Augusto …

Planting Date, Cultivar, Seed Treatment, And Seeding Rate Effects On Soybean Growth And Yield, Thandiwe Nleya, Matthew Schutte, David Clay, Graig Reicks, Nathan Mueller

West Central Research and Extension Center, North Platte

Soybean [Glycine max (L.) Merr.] yield is a function of many factors including genetic attributes of the cultivar, environmental conditions, and management practices. Temporally variable weather patterns in North America, especially in the northern Great Plains, have resulted in the re-examination of how spring production practices interact with the environmental conditions to influence yield. This study evaluated the impact of four plantings dates, four seeding rates, and two soybean maturity groups (MGs) using treated and untreated (control) seed on soybean growth, seed yield, and composition. The study was conducted at Volga, SD, in 2014, 2015, and 2016. The planting …

Comparison Of Water-Sensitive Paper, Kromekote And Mylar Collectors For Droplet Deposition With A Visible Fluorescent Dye Solution, J. Connor Ferguson, Andrew J. Hewitt, Chris C. O’Donnell, Greg R. Kruger

West Central Research and Extension Center, North Platte

The study was conducted at the University of Nebraska Pesticide Application and Tech-nology Laboratory in North Platte, Nebraska in July 2015. Two application volume rates (100 and 200 l · ha−1) and three nozzle types (XR, AIXR, TTI) were selected at two flow rates (0.8 and 1.6 l · min−1) and at a single application speed of 7.7 km · h−1. Each collec-tor type [Mylar washed (MW), Mylar image analysis (MIA), water-sensitive paper (WSP), and Kromekote (KK)] was arranged in a randomized complete block design. Each nozzle treatment was replicated twice, providing six cards of each collector type for each …

Herbicide Drift Exposure Leads To Reduced Herbicide Sensitivity In Amaranthus Spp., Bruno Viera, Joe Luck, Keenan Amundsen, Rodrigo Werle, Todd A. Gaines, Greg R. Kruger

West Central Research and Extension Center, North Platte

While the introduction of herbicide tolerant crops provided growers new options to manage weeds, the widespread adoption of these herbicides increased the risk for herbicide spray drift to surrounding vegetation. The impact of herbicide drift in sensitive crops is extensively investigated, whereas scarce information is available on the consequences of herbicide drift in non-target plants. Weeds are often abundant in field margins and ditches surrounding agricultural landscapes. Repeated herbicide drift exposure to weeds could be detrimental to long-term management as numerous weeds evolved herbicide resistance following recurrent-selection with low herbicide rates. The objective of this study was to evaluate if …

The Impact Of Cow Size On Cow–Calf And Postweaning Progeny Performance In The Nebraska Sandhills, Rob L. Ziegler, Jacki A. Musgrave, Tanya L. Meyer, R. Funston, Elliott James Dennis, Kathy Hanford, J. C. Macdonald, Travis Mulliniks

West Central Research and Extension Center, North Platte

Optimizing beef production system efficiency requires an understanding of genetic potential suitable for a given production environment. Therefore, the objective of this retrospective analysis was to determine the influence of cow body weight (BW) adjusted to a common body condition score (BCS) of 5 at weaning-influenced cow-calf performance and postweaning steer and heifer progeny performance. Data were collected at the Gudmundsen Sandhills Laboratory, Whitman, NE, on crossbred, mature cows (n = 1,607) from 2005 to 2017. Cow BCS at calving, prebreeding, and weaning were positively associated (P < 0.01) with greater cow BW. Increasing cow BW was positively associated (P < 0.01) with the percentage of cows that conceived during a 45-d breeding season. For every additional 100-kg increase in cow BW, calf BW increased (P < 0.01) at birth by 2.70 kg and adjusted 205-d weaning BW by 14.76 kg. Calf preweaning average daily gain (ADG) increased (P < 0.01) 0.06 kg/d for every additional 100-kg increase in cow BW. Heifer progeny BW increased (P < 0.01) postweaning with every additional 100-kg increase in dam BW. Dam BW did not influence (P ≥ 0.11) heifer puberty status prior to breeding, overall pregnancy rates, or the percentage of heifers calving in the first 21 d of the calving season. Steer initial feedlot BW increased by 7.20 kg, reimplant BW increased by 10.47 kg, and final BW increased by 10.29 kg (P ≤ 0.01) for every additional 100-kg increase in dam BW. However, steer feedlot ADG was not influenced (P > 0.67) by dam BW. Hot carcass weights of steers were increased (P = …

Diurnal And Seasonal Activity Patterns Of Drosophilid Species (Diptera: Drosophilidae) Present In Blackberry Agroecosystems With A Focus On Spotted-Wing Drosophila, Katharine A. Swoboda-Bhattarai, Hannah Burrack

West Central Research and Extension Center, North Platte

Drosophilid species with different life histories have been shown to exhibit similar behavioral patterns related to locating and utilizing resources such as hosts, mates, and food sources. Drosophila suzukii (Matsumura) is an invasive species that differs from other frugivorous drosophilids in that females lay eggs in ripe and ripening fruits instead of overripe or rotten fruits. We hypothesized that there may be diurnal and/or seasonal patterns associated with the movement of drosophilid species into and out of crop fields and their attraction to fermentation-odor-based monitoring traps, and that D. suzukii would conform to similar patterns. To test these hypotheses, we …

Managing Invasive Plants On Great Plains Grasslands: A Discussion Of Current Challenges, John Gaskin, Erin Espeland, Casey D. Johnson, Jane M. Mangold, Rachel A. Mcgee, Chuck Milner, Shishir Paudel, Dean E. Pearson, Lora B. Perkins, Chadley W. Prosser, Justin B. Runyon, Sharlene E. Sing, Zachary A. Sylvain, Amy J. Symstad, Daniel R. Tekiela

Native Plant Focused Publications

The Great Plains of North America encompass approximately 1,300,000 km² of land from Texas to Saskatchewan. The integrity of these lands is under continual assault by long-established and newly-arrived invasive plant species, which can threaten native species and diminish land values and ecological goods and services by degrading desired grassland resources. The Great Plains are a mixture of privately and publicly owned lands, which leads to a patchwork of varying management goals and strategies for controlling invasive plants. Continually updated knowledge is required for efficient and effective management of threats posed by changing environments and invasive plants. Here we …

Captive Ring-Necked Pheasant Response To Very High Experimental Doses Of Lead, Travis J. Runia, Alex J. Solem

The Prairie Naturalist

Ingestion of spent lead pellets is a well-documented source of lead exposure in free-ranging birds, although the consequence of lead ingestion varies widely among avian guilds. Ring-necked pheasants (Phasianus colchicus) appear to be less susceptible to lead poisoning than other game birds. Our objectives were to determine survival, liver lead accumulation, and body mass change of 129 captive-raised pheasants in response to being gavage-fed 5, 10, 20, or 40 lead pellets. All pheasants survived the 21-day experiment. Liver-lead levels were positively correlated with the number of lead pellets retained and negatively correlated with beginning body mass. Change in percent body …

Evaluation Of Four Larval Fish Sampling Methods In A Large Midwestern River, Nathan J. Lederman, Anthony R. Sindt, Douglas J. Dieterman, John D. Krenz, Shannon J. Fisher

The Prairie Naturalist

Understanding limitations of larval fish capture gears is critical for developing appropriate sampling protocols and interpreting catch data. We evaluated genera richness, genera diversity, assemblage similarities, abundance indices (i.e., density or catch per unit effort [CPUE]), and sample size requirements between a surface slednet and glow-stick light traps used in 2014 and 2015 and a benthic slednet and light-emitting diode light (LED) traps used in 2015 in the Minnesota River. The surface slednet captured the greatest number of larval fish genera (15) while the LED light trap captured the fewest (1). Similarities of assemblages sampled was highest between surface and …

Comparing Native Bee Communities On Reconstructed And Remnant Prairie In Missouri, Joseph Larose, Elisabeth B. Webb, Deborah Finke

The Prairie Naturalist

The tallgrass prairie of North America is an imperiled ecosystem that has been the subject of considerable restoration effort and research in the past two decades. While native prairie plant species are purposely introduced during restoration, prairie invertebrates, including native bees (Anthophila), are not and must colonize from surrounding remnants. Prairie restorations may not support the same bee communities as remnant prairies because of habitat differences and dispersal limitations. We sampled native bees on reconstructed and remnant prairies in Missouri in the summers of 2016 and 2017 and compared the communities by evaluating species richness, diversity, and community composition. We …

Greater Prairie-Chickens And Sharp-Tailed Grouse Have Similarly High Nest Survival In The Nebraska Sandhills, Larkin Powell, Walter Schacht, Julia P. Ewald, Kathryn R. Mccollum

The Prairie Naturalist

The ranges of two native galliform species overlap in the Nebraska Sandhills, the largest contiguous grassland in North America. We monitored nests of greater prairie-chickens (Tympanuchus cupido) and sharp-tailed grouse (Tympanuchus phasianellus) in Cherry County, Nebraska, in 2015 and 2016. Our objectives were to 1) compare daily probability of nest survival between species, 2) evaluate vegetation structure at nests for potential effects on nest survival, 3) compare nest site topography between species, and 4) use a simple model of breeding season success to evaluate the potential for stable populations at our study sites. We captured and …

Impacts Of Rock Climbing On Lichen And Bryophyte Cliff Communities In The Arid West, Giovanna M. Bishop

2020 Symposium Posters

Lichens and bryophytes make up the majority of the diversity and cover in cliff systems around the world. Recently, with the rapid rise of rock climbing, there are concerns rock climbers are negatively impacting cliff communities. My study will compare climbed and unclimbed granite cliffs to better understand the impacts of rock climbing on lichen and bryophyte diversity and cover in eastern Washington. The objectives of this study are to assess the impacts of rock climbing on lichen and bryophyte cliff community diversity and cover and improve route development and cliff management practices for lichens and bryophytes. This study will …

Temperate Eurasian Origins Of Hawaiian Chenopodium (Amaranthaceae) Plus Description Of A New Species Endemic To Moloka‘I, Jason T. Cantley, Angela J. Mcdonnell, J Branson, S R. Long, W Garnett, Christopher T. Martine

Faculty Journal Articles

Chenopodium taxa of Hawai‘i are tetraploids distinguished from other members of the circumglobally distributed genus by minute morphological characters. Because of these reasons, the geographic origin of Hawaiian Chenopodium has remained unclear. Across the Hawaiian Archipelago, Chenopodium taxa are morphologically variable and grow in highly disparate xeric habitats, especially in terms of precipitation, temperature, wind, salt spray, and solar irradiation. Habitats include dry subalpine shrublands, sandy beach strand of atolls in the Northwest Hawaiian Islands, dry forests, and precipitously tall sea cliffs of northwestern Moloka‘i. From the Moloka‘i sea cliffs, which are battered by high energy winds, salt spray, and …

The Chumash Heritage National Marine Sanctuary: An Exploration Of Changing The Discourse On Conservation, Arielle Ben-Hur

Pitzer Senior Theses

In 2015, the Northern Chumash Tribal Council submitted a National Marine Sanctuary Nomination to establish the Chumash Heritage National Marine Sanctuary– a means by which to ensure the protection of one of the most culturally and biologically diverse coastlines in the world. On October 5, 2015, John Armor of the National Oceanic and Atmospheric Administration (NOAA) responded to the nomination, adding it to the inventory of areas NOAA may consider in the future for national marine sanctuary designation.

In my thesis, I explore how the nomination of the Chumash Heritage National Marine Sanctuary acts as a platform from which Traditional …

Belowground Characteristics Of Dominant Coastal Dune Grasses And Potential Community-Level Effects On Coastal Erosion, Shannon L. Walker

Theses and Dissertations

Natural dunes arise out of complex relationships between ecological, hydrological, and geological processes and are important for reducing erosion along coastlines. Aboveground structures of coastal dune grasses are known to impact erosional dynamics, and recent studies have shown that belowground structures—such as roots, rhizomes, and belowground stems— may be important in erosional resistance. My objectives were to 1) characterize above- and belowground characteristics of prominent dune grasses and 2) combine these data with functional group abundances and distribution to evaluate community effects on two adjacent locations of distinctive morphology and erosional characteristics and their response to storm disturbance. Whole plant …

The Origin And Evolution Of Flower Characters In Angiosperms With A Case Study On The Genetic Basis Of Zygomorphic Corolla Development In Bee And Hummingbird Pollinated Species Of Schizanthus (Solanaceae), Ghadeer Bukhari

Theses and Dissertations

This Ph.D. dissertation investigates two main projects separated into two chapters, one for each. The first chapter explores the evolution of flowering plants (angiosperms), a macro-scale study. The second project is on a micro-scale that focus on exploring the genes that regulate the similarities and the differences of flower morphology reflecting their different pollination syndromes in two species of Schizanthus (Solanaceae), i.e., S. pinnatus, a bee-pollinated flower, and S. grahamii, a hummingbird- pollinated flower.

In the first chapter, I used floral diagrams to study the origin and the evolution of floral traits in angiosperms, a new set of morphological data …

Dispelling The Mirage Of C4-Driven Drought Tolerance In Poaceae: A Phylogenomic Study, Matthew P. Nissenbaum

Graduate Research Theses & Dissertations

Climate change has been considered a key driver for adaptations in water usage efficiency (WUE) in plants. Perceptions persist that C4 photosynthesis is indicative of some level of WUE. Here, we examined the interaction and evolution of WUE within the grass family, Poaceae, as it pertains to photosynthetic pathway. Unique to this study is the magnitude of taxa sampled, presence of intrageneric sampling, and use of complete plastid genomes (plastomes) for phylogenomic analyses.

310 species were sampled, including 26 with newly sequenced plastomes, which were assembled de novo from next-generation sequencing data. Additional plastomes were downloaded from the National Center …

Patterns Of Epiphytic Lichen Abundance On Aspen Stands In Proximity To Roads Of Varying Vehicular Traffic, D. Aragon, C. Castillo, J. Moffroid, G. Thomas

Aspen Bibliography

Although present in nearly any wild space with available moisture and on a wide variety of substrates, lichen, and its importance as a bioindicator for an ecosystem, is often overlooked. As air pollution becomes a greater concern for flora, fauna, and even humans, the story told by lichen growth becomes more useful as we try to make sense of the downstream effects of anthropogenic contributions to poor air quality. One such human-driven pollutant is the level of emissions that result from vehicular travel. The Jackson Hole area has experienced a large increase in vehicular traffic in the past five to …

Pando Clone Recovery: Repeat Photos 2014-2019, Mary O'Brien, Marc Coles-Ritchie

Aspen Bibliography

The world's largest known clone of aspen (Populus tremuloides), called the "Pando Clone" is located in the Fishlake National Forest in central Utah. For many decades, significant pressure from ungulate (deer and cattle) browsing has prevented growth of young aspen stems in to trees that would replace the mature trees as they die of natural causes. There has been concern that this impressive 104-acre Pando Clone could be lost altogether due to the excessive browsing of young aspen stems. In 2013, 16 acres of this clone were fenced to exclude all ungulates (deer and cattle) so that recovery …

Geographic Distribution Of Bacillus Thuringiensis Cry1f Toxin Resistance In Western Bean Cutworm (Lepidoptera: Noctuidae) Populations In The United States, Brad S. Coates, Craig A. Abel, Katharine A. Swoboda-Bhattarai, Debra E. Palmquist, Débora Goulart Montezano, Sarah N. Zukoff, Yangzhou Wang, Jeffery D. Bradshaw, Christina D. Difonzo, Elson Shields, Kelley J. Tilmon, Thomas Hunt, Julie A. Peterson

West Central Research and Extension Center, North Platte

The western bean cutworm (WBC), Striacosta albicosta (Lepidoptera: Noctuidae), can be a severe pest of transgenic corn in the western Plains and Great Lakes regions of North America, including on hybrids expressing the Bacillus thuringiensis (Bt) Cry1F toxin. The level and geographic distribution of Cry1F resistance are not completely known. Neonate S. albicosta from 10 locations between Nebraska and New York state were subjected to dose–response trypsin-activated native Cry1F toxin overlay bioassays. In 2017, the mean estimated lethal concentration causing 50% larval mortality (LC50) ranged from 15.1 to 18.4 μg Cry1F cm−2, and were not significantly different among locations. In …

Agroecosystems Entomology Lab, Research Summary 2020

West Central Research and Extension Center, North Platte

Contents

Introduction: Agroecosystems Entomology Lab

Project # 1: Chemigation efficacy and spray deposition on corn for the control of western bean cutworm

Project #2: Insecticide application on western bean cutworm eggs and response of predators to treated eggs

Project #3: Investigating the Role of Spiders in Integrated Pest Management for Biological Control of Nebraska Crop Pests

Project #4: Modeling the potential global geographic distribution of Striacosta albicosta using MaxEnt

Project #5: Diversity and abundance of arthropods in industrial hemp fields of Nebraska

The Influence Of Land Use On The Pollen Diet Of Honey Bee (Apis Mellifera) Colonies In Ellis County, Kansas, Ryan Engel

Master's Theses or Doctor of Nursing Practice

Pollinators are integral to plant ecology as well as to worldwide food availability and security. Understanding how human-driven land use change impacts the nutrition of managed honey bees is important in pollinator conservation efforts and can contribute towards combating recent pollinator declines. The objective of this study was to determine sources of forage for honey bees across different land use types in Ellis County, Kansas, through pollen analysis and taxonomic identification. Replicate study colonies were placed in three separate land use types: Urban, Cropland, or Native/Semi-native prairie. Pollen was sampled every 7 to 14 days throughout a growing season (April …