Ecology and Evolutionary Biology Commons^™

Patterns For Populus Spp. Stand Biomass In Gradients Of Winter Temperature And Precipitation Of Eurasia, Vladimir Andreevich Usoltev, Baozhang Chen, Seyed Omid Reza Shobairi, Ivan Stepanovich Tsepordey, Viktor Petrovich Chasovskikh, Shoaib Ahmad Anees

Aspen Bibliography

Based on a generated database of 413 sample plots, with definitions of stand biomass of the genus Populus spp. in Eurasia, from France to Japan and southern China, statistically significant changes in the structure of forest stand biomass were found, with shifts in winter temperatures and average annual precipitation. When analyzing the reaction of the structure of the biomass of the genus Populus to temperature and precipitation in their transcontinental gradients, a clearly expressed positive relationship of all components of the biomass with the temperature in January is visible. Their relationship with precipitation is less clear; in warm climate zones, …

Differences In Soil Water Changes And Canopy Temperature Under Varying Water × Nitrogen Sufficiency For Maize, Tsz Him Lo, Daran Rudnick, Kendall C. Dejonge, Geng Bai, Hope Njuki Nakabuye, Abia Katimbo, Yufeng Ge, Trenton E. Franz, Xin Qiao, Derek M. Heeren

West Central Research and Extension Center, North Platte

Crop nitrogen (N) status is known to affect crop water status and crop water use. To investigate further the N effects on soil water changes and on canopy temperature, three water levels × four N levels were imposed on two growing seasons of maize in west central Nebraska, USA. Soil water changes were measured using a neutron probe, whereas canopy temperature was measured using infrared thermometers on a ground-based mobile platform. At all water levels, soil water losses over monthlong intervals were generally greater as N levels increased. Given equal water levels, early afternoon canopy temperatures were usually lower with …

Genomic Insights Into Speciation History And Local Adaptation Of An Alpine Aspen In The Qinghai–Tibet Plateau And Adjacent Highlands, Jia-Lang Li, Lin-Ling Zhong, Jing Wang, Tao Ma, Kang-Shan Mao, Lei Zhang

Aspen Bibliography

Natural selection serves as an important agent to drive and maintain interspecific divergence. Populus rotundifolia Griff. is an alpine aspen species that mainly occurs in the Qinghai–Tibet Plateau (QTP) and adjacent highlands, whereas its sister species, P. davidiana Dode, is distributed across southwest and central to northeast China in much lower altitude regions. In this study, we collected genome resequencing data of 53 P. rotundifolia and 42 P. davidiana individuals across their natural distribution regions. Our population genomic data suggest that the two species are well delimitated in the allopatric regions, but with hybrid zones in their adjacent region in …

Aspen Next Generation: Conversations From Southern Colorado And Northern New Mexico, Dan Binkley, Bill Romme

Aspen Bibliography

Aspen trees and forests are especially important in the Rocky Mountains. Aspens add beauty to landscapes, foster high diversity and productivity of understory plants, provide for the habitat needs of many species of animals, and moderate fire behavior. There is a perception that aspen trees and stands are not regenerating well in southern Colorado and northern New Mexico; cohorts of trees younger than a few decades are scarce, at least in some areas. The next generation of aspen in the southern Rockies will be influenced by land use decisions, including harvesting, fire policy and management, and browsing by livestock and …

Long-Term Soil Productivity Study: 25-Year Vegetation Response To Varying Degrees Of Disturbance In Aspen-Dominated Forest Spanning The Upper Lake States, Miranda T. Curzon, Brian J. Palik, Anthony W. D'Amato, Julia Schwager

Aspen Bibliography

Installations of the Long-Term Soil Productivity Study were established in northern Minnesota and Michigan at the Chippewa, Ottawa, and Huron-Manistee National Forests (NFs) in the early 1990s and have since provided a wealth of data for assessing the response of aspen-dominated forest ecosystems to varying levels of organic matter removal and soil compaction. An assessment of 25-year standing woody biomass indicates that neither whole-tree harvest nor whole-tree harvest combined with forest floor removal reduced forest productivity on silt-loam soils compared with conventional, stem-only harvest; however, moderate and heavy compaction did negatively impact aspen biomass and stem densities. In contrast, whole-tree …

Storm Surges In The Bohai Sea: The Role Of Waves And Tides, Yuanyi Li, Huan Feng, Guillaume Vigouroux, Dekui Yuan, Guangyu Zhang, Xiaodi Ma, Kun Lei

Department of Earth and Environmental Studies Faculty Scholarship and Creative Works

A storm surge is a complex phenomenon in which waves, tide and current interact. Even though wind is the predominant force driving the surge, waves and tidal phase are also important factors that influence the mass and momentum transport during the surge. Devastating storm surges often occur in the Bohai Sea, a semi-enclosed shallow sea in North China, due to extreme storms. However, the effects of waves on storm surges in the Bohai Sea have not been quantified and the mechanisms responsible for the higher surges that affect part of the Bohai Sea have not been thoroughly studied. In this …

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.

Teaching Natural And Artificial Selection In Production Agriculture, Madhav P. Nepal, Clayton W. Scott

iLEARN Teaching Resources

In this lesson, students will learn how natural selection and artificial selection impact both production agriculture and biological sciences. A natural selection is a mechanism that favors heritable traits that increase species survival and reproduction. Artificial selection is a selective breeding, where humans select for desirable traits in agricultural products.

Investigating Bat Activity In Various Agricultural Landscapes In Northeastern United States, Katherine Harms, Emmanuel Omondi, Atanu Mukherjee

Agricultural and Environmental Sciences Faculty Research

Bats are estimated to provide between $3.7 and $53 billion annually in ecosystem services in the U.S.A. Determining how bats use land for foraging is important in planning agricultural landscapes to increase their presence and role in insect pest control. A research project was established in 2016 and 2017 to determine bat populations and activity differences between different land use management systems. Bat activity was monitored in 10 conventionally and organically managed systems in the presence of, and at a distance from the tree line. Two acoustic monitoring devices were used to record ultrasonic echolocation calls of bats. Organic systems …

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 …

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 …

Statistical Analysis Of Nutrient Loads From The Mississippi-Atchafalaya River Basin (Marb) To The Gulf Of Mexico, Phyllis Okwan, Yi Zhen, Huan Feng, Shinjae Yoo, Murty S. Kambhampati, Abreione Walker, Shayne Boykin, Joe Omojola, Noel Blackburn

Department of Earth and Environmental Studies Faculty Scholarship and Creative Works

This study investigated the annual and seasonal variations in nutrient loads (NO₂⁻ + NO₃⁻ and orthophosphate) delivered to the Gulf of Mexico from the Mississippi-Atchafalaya River Basin (MARB) and examined the water quality variations. The results indicate that (1) annually, the mean NO₂⁻ + NO₃⁻ and orthophosphate loads showed a steady increase during 1996–1999, a persistent level during 2000–2007, and a moderate increase during 2008–2016; (2) seasonally, NO₂⁻ + NO₃⁻ and orthophosphate in MARB in spring and summer were higher than those in autumn and winter. Analysis of …

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 …

Understanding How Agricultural Intensification Impacts Ring-Necked Pheasant Distribution And Survival In Eastern South Dakota, Hilary R. Kauth

Electronic Theses and Dissertations

Historically, pheasants (Phasianus colchicus) have thrived in South Dakota in conjunction with successful land retirement programs or early farming practices through the 1950s, which created interspersions of agriculture and native landscapes that were ideal for pheasants. Recently, the Prairie Pothole ecosystem has undergone rapid agroeconomic expansion, effectively reducing ideal interspersions of native prairie and cropland into agriculturally homogeneous landscapes. Indices of pheasant abundance have suggested persistent population declines since 2008, raising concerns regarding landscape suitability. Our goal was to understand how agriculture intensification impacts pheasant ecology. The objectives were to: 1) estimate overwinter hen probability of survival, resource …

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

Innovation In Meat Production: A Problem And An Opportunity, Christopher J. Bryant

Animal Sentience

Innovation in meat production has enabled modern humans to inflict far greater harm on animals, the environment, and public health than was possible just a few decades ago. Wiebers & Feigin aptly express the urgency with which these issues must be addressed. Those advocating for animals on moral grounds face resistance from omnivores citing taste, price and convenience. Further innovation in meat production (plant-based and cultured meat) will enable us to preserve the experience of eating meat whilst phasing out the many problems caused by industrial animal farming.

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 …

Spatiotemporal Partitioning Of Mammalian Mesopredators In Response To Drought And Urbanization In California's Central Valley, Chad W. Moura

Cal Poly Humboldt theses and projects

Mammalian mesopredators commonly associated with human dominated landscapes often exhibit generalist diets, behavioral plasticity, and relatively high reproductive rates. Because of this wide range of adaptive traits, ecologists have been speculative of what conditions may drive species to change their activity and behavior to avoid or mitigate against resource competition, intraguild predation, and human disturbance. I investigated a community of common mesopredators within the Sacramento Metropolitan Area of California’s Central Valley to address whether species are spatially and/or temporally partitioning due to a defacto apex predator, coyotes (Canis latrans), and humans alongside large landscape altering disturbances: urbanization and drought. I …

Snowpack Properties Vary In Response To Burn Severity Gradients In Montane Forests, Jordan Maxwell, Samuel B. St. Clair

Aspen Bibliography

Wildfires are altering ecosystems globally as they change in frequency, size, and severity. As wildfires change vegetation structure, they also alter moisture inputs and energy fluxes which influence snowpack and hydrology. In unburned forests, snow has been shown to accumulate more in small clearings or in stands with low to moderate forest densities. Here we investigate whether peak snowpack varies with burn severity or percent overstory tree mortality post-fire in a mid-latitude, subalpine forest. We found that peak snowpack across the burn severity gradients increased 15% in snow-water equivalence (SWE) and 17% in depth for every 20% increase in overstory …

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 …

Future Climate Change Will Have A Positive Effect On Populus Davidiana In China, Jie Li, Guan Liu, Qi Lu, Yanru Zhang, Guoqing Li, Sheng Du

Aspen Bibliography

Since climate change significantly affects global biodiversity, a reasonable assessment of the vulnerability of species in response to climate change is crucial for conservation. Most existing methods estimate the impact of climate change on the vulnerability of species by projecting the change of a species’ distribution range. This single-component evaluation ignores the impact of other components on vulnerability. In this study, Populus davidiana (David’s aspen), a tree species widely used in afforestation projects, was selected as the research subject under four future climate change scenarios (representative concentration pathway (RCP)2.6, RCP4.5, RCP6.0, and RCP8.5). Exposure components of range change as well …