Physical Sciences and Mathematics Commons^™

Catfish Population Characteristics Among River Segments With Altered Fluvial Geomorphic Conditions In The Missouri River, Nebraska, Usa, Martin J. Hamel, Jonathan J. Spurgeon, Mark A. Pegg

School of Natural Resources: Faculty Publications

Alteration of river systems around the world has created novel environments that have been fragmented, homogenized, or transformed from their natural state, thus posing challenges for understanding how fish populations function. The Missouri River has undergone significant alteration through reservoir construction and channelization. Channel Catfish Ictalurus punctatus and Flathead Catfish Pylodictis olivaris both reside in various fragmented sections of the river, and there is a substantial gap in knowledge of how catfishes synchronously function in this modified system. From 2009 to 2018, we assessed catfishes with baited hoop nets and low-frequency electrofishing among four different areas: upper and lower unchannelized …

A Review Of Vegetation Phenological Metrics Extraction Using Time-Series, Multispectral Satellite Data, Linglin Zeng, Brian D. Wardlow, Daxiang Xiang, Shun Hu, Deren Li

School of Natural Resources: Faculty Publications

Vegetation dynamics and phenology play an important role in inter-annual vegetation changes in terrestrial ecosystems and are key indicators of climate-vegetation interactions, land use/land cover changes, and variation in year-to-year vegetation productivity. Satellite remote sensing data have been widely used for vegetation phenology monitoring over large geographic domains using various types of observations and methods over the past several decades. The goal of this paper is to present a detailed review of existing methods for phenology detection and emerging new techniques based on the analysis of time-series, multispectral remote sensing imagery. This paper summarizes the objective and applications of detecting …

The Role Of Topography, Soil, And Remotely Sensed Vegetation Condition Towards Predicting Crop Yield, Trenton E. Franz, Sayli Pokal, Justin P. Gibson, Yuzhen Zhou, Hamed Gholizadeh, Fatima Amor Tenorio, Daran Rudnick, Derek M. Heeren, Matthew F. Mccabe, Matteo Ziliani, Zhenong Jin, Kaiyu Guan, Ming Pan, John Gates, Brian Wardlow

School of Natural Resources: Faculty Publications

Foreknowledge of the spatiotemporal drivers of crop yield would provide a valuable source of information to optimize on-farm inputs and maximize profitability. In recent years, an abundance of spatial data providing information on soils, topography, and vegetation condition have become available from both proximal and remote sensing platforms. Given the wide range of data costs (between USD $0−50/ha), it is important to understand where often limited financial resources should be directed to optimize field production. Two key questions arise. First, will these data actually aid in better fine-resolution yield prediction to help optimize crop management and farm economics? Second, what …

Leveraging Image Analysis For High-Throughput Plant Phenotyping, Sruti Das Choudhury, Ashok Samal, Tala Awada

School of Natural Resources: Faculty Publications

The complex interaction between a genotype and its environment controls the biophysical properties of a plant, manifested in observable traits, i.e., plant’s phenome, which influences resources acquisition, performance, and yield. High-throughput automated image-based plant phenotyping refers to the sensing and quantifying plant traits non-destructively by analyzing images captured at regular intervals and with precision. While phenomic research has drawn significant attention in the last decade, extracting meaningful and reliable numerical phenotypes from plant images especially by considering its individual components, e.g., leaves, stem, fruit, and flower, remains a critical bottleneck to the translation of advances of phenotyping technology into genetic …

Gene Flow From Single And Stacked Herbicide-Resistant Rice (Oryza Sativa): Modeling Occurrence Of Multiple Herbicide-Resistant Weedy Rice, Joseph Dauer, Andrew Hulting, Dale Carlson, Luke Mankin, John Harden, Carol Mallory-Smith

School of Natural Resources: Faculty Publications

Background: Provisia™ rice (PV), a non-genetically engineered (GE) quizalofop-resistant rice, will provide growers with an additional option for weed management to use in conjunction with Clearfield® rice (CL) production. Modeling compared the impact of stacking resistance traits versus single traits in rice on introgression of the resistance trait to weedy rice (also called red rice). Common weed management practices were applied to 2-, 3- and 4-year crop rotations, and resistant and multiple-resistant weedy rice seeds, seedlings and mature plants were tracked for 15 years.

Results: Two-year crop rotations resulted in resistant weedy rice after 2 years with abundant populations (exceeding …

Acoustic Characteristics Of Lekking Male Greater Prairie-Chicken (Tympanuchus Cupido Pinnatus) Vocalizations (Supplement), Cara E. Whalen, Mary Bomberger Brown, Joann Mcgee, Larkin A. Powell, Edward J. Walsh

School of Natural Resources: Faculty Publications

Boom

Cackle

Whine

Whoop

Exploring Elementary Students’ Scientific Knowledge Of Agriculture Using Evidence-Centered Design, Molly Brandt, Cory Forbes, Jenny Keshwani

School of Natural Resources: Faculty Publications

The public is more disconnected from agriculture than ever. Americans are now two to four generations removed from the farm with a majority of Americans having no direct experience in agriculture. As a result, the public lacks the knowledge and appreciation of the food, fuel, and fiber it demands. The National Agricultural Learning Objectives (NALOs) were recently developed to describe students’ agricultural knowledge but have, as yet, not been used to guide research into students’ agricultural literacy. The purpose of this project is to further understand students’ agricultural literacy through NALO-based assessment of students’ knowledge. This study focused on the …

Assessment Of A Channel Catfish Population In A Large Open River System, A. J. Blank, M. J. Hamel, Jonathan J. Spurgeon, Mark A. Pegg

School of Natural Resources: Faculty Publications

Estimates of dynamic rate functions for riverine channel catfish, Ictalurus punctatus (Rafinesque), populations are limited. The open nature and inherent difficulty in sampling riverine environments and the propensity for dispersal of channel catfish impede estimation of population variables. However, contemporary population models (i.e. robust design models) can incorporate the open nature of these systems. The purpose of this study was to determine channel catfish population abundance, survival and size structure and to characterize growth in the lower Platte River, Nebraska, USA. Annual survival estimates of adult channel catfish were 13%–49%, and channel catfish abundance estimates ranged from 8,281 to 24,261 …

Fluctuating Survival Selection Explains Variation In Avian Group Size, Charles R. Brown, Mary Bomberger Brown, Erin A. Roche, Valerie A. O'Brien, Catherine E. Page

School of Natural Resources: Faculty Publications

Most animal groups vary extensively in size. Because individuals in certain sizes of groups often have higher apparent fitness than those in other groups, why wide group size variation persists in most populations remains unexplained. We used a 30-y mark– recapture study of colonially breeding cliff swallows (Petrochelidon pyrrhonota) to show that the survival advantages of different colony sizes fluctuated among years. Colony size was under both stabilizing and directional selection in different years, and reversals in the sign of directional selection regularly occurred. Directional selection was predicted in part by drought conditions: birds in larger colonies tended …

Acoustic Detection Reveals Fine-Scale Distributions Of Myotis Lucifugus, Myotis Septentrionalis, And Perimyotis Subflavus In Eastern Nebraska, Jeremy A. White, Cliff Lemen, Patricia Freeman

School of Natural Resources: Faculty Publications

ABSTRACT.—Before white-nose syndrome arrives in Nebraska, it is important to document the preexposure distributions of cave bats in the state. We examined the distributions of Myotis lucifugus (little brown myotis), Myotis septentrionalis (northern long-eared myotis), and Perimyotis subflavus (tri-colored bat) in eastern Nebraska by setting acoustic detectors for a single night at 105 sites in wooded habitats during summers of 2012 and 2014. We compared 2 methods of determining presence at each site. Results of our analyses are fine-scale distributional maps for these bats and some range extensions from published records. Results for M. septentrionalis and P. subflavus are largely …

Flight Initiation Distances Of Nesting Piping Plovers (Charadrius Melodus) In Response To Human Disturbance, Joel G. Jorgensen, Lauren R. Dinan, Mary Bomberger Brown

School of Natural Resources: Faculty Publications

Birds frequently interact with people when they occur in coupled human-ecological or anthropogenic environments, which makes the protection of legally protected species a challenge. Flight initiation distances (FIDs) are often used to inform development of appropriate buffer distances required for human exclusion zones used to protect birds nesting in anthropogenic landscapes. Piping Plovers (Charadrius melodus) are protected by the Endangered Species Act in the United States and often nest in areas used by humans. Studies evaluating Piping Plover FIDs are limited and implementation of exclusion zones has been inconsistent across the species’ range. We measured Piping Plover response …

Temporal Variability In Aboveground Plant Biomass Decreases As Spatial Variability Increases, Devan Allen Mcgranahan, Torre J. Hovick, R. Dwayne Elmore, David M. Engle, Samuel D. Fuhlendorf, Stephen L. Winter, James R. Miller, Diane M. Debinski

School of Natural Resources: Faculty Publications

Ecological theory predicts that diversity decreases variability in ecosystem function. We predict that, at the landscape scale, spatial variability created by a mosaic of contrasting patches that differ in time since disturbance will decrease temporal variability in aboveground plant biomass. Using data from a multi-year study of seven grazed tallgrass prairie landscapes, each experimentally managed for one to eight patches, we show that increased spatial variability driven by spatially patchy fire and herbivory reduces temporal variability in aboveground plant biomass. This pattern is associated with statistical evidence for the portfolio effect and a positive relationship between temporal variability and functional …

Temporal Variability In Aboveground Plant Biomass Decreases As Spatial Variability Increases, Devan Allen Mcgranahan, Torre J. Hovick, R. Dwayne Elmore, David M. Engle, Samuel D. Fuhlendorf, Stephen L. Winter, James R. Miller, Diane M. Debinski

School of Natural Resources: Faculty Publications

Ecological theory predicts that diversity decreases variability in ecosystem function. We predict that, at the landscape scale, spatial variability created by a mosaic of contrasting patches that differ in time since disturbance will decrease temporal variability in aboveground plant biomass. Using data from a multi-year study of seven grazed tallgrass prairie landscapes, each experimentally managed for one to eight patches, we show that increased spatial variability driven by spatially patchy fire and herbivory reduces temporal variability in aboveground plant biomass. This pattern is associated with statistical evidence for the portfolio effect and a positive relationship between temporal variability and functional …

Parent-Offspring Resemblance In Colony-Specific Adult Survival Of Cliff Swallows, Charles R. Brown, Erin A. Roche, Mary Bomberger Brown

School of Natural Resources: Faculty Publications

Survival is a key component of fitness. Species that occupy discrete breeding colonies with different characteristics are often exposed to varying costs and benefits associated with group size or environmental conditions, and survival is an integrative net measure of these effects. We investigated the extent to which survival probability of adult (≥ 1-year old) cliff swallows (Petrochelidon pyrrhonota) occupying different colonies resembled that of their parental cohort and thus whether the natal colony had long-term effects on individuals. Individuals were cross-fostered between colonies soon after hatching and their presence as breeders monitored at colonies in the western Nebraska …

Variation In Avian Vocalizations During The Non-Breeding Season In Response To Traffic Noise, Amy I. Oden, Mary Bomberger Brown, Mark E. Burbach, James R. Brandle, John E. Quinn

School of Natural Resources: Faculty Publications

Low-frequency traffic noise that leads to acoustic masking of vocalizations may cause birds to alter the frequencies or other components of their vocalizations in order to be heard by conspecifics and others. Altering parts of a vocalization may result in poorer vocal performance or the message contained in the vocalization being received incorrectly. During the winters of 2011–2012 and 2012–2013, we recorded and measured the “chick-a-dee” call of Black-capped Chickadees (Poecile atricapillus) and the “po-ta-to-chip” call of American Goldfinches (Spinus tristis) to determine whether components of the calls produced in areas of high traffic noise and …

Uncertainty In Simulating Gross Primary Production Of Cropland Ecosystem From Satellite-Based Models, Wenping Yuan, Wenwen Cai, Anthony L. Nguy-Robertson, Huajun Fang, Andrew E. Suyker, Yang Chen, Wenjie Dong, Shuguang Liu, Haicheng Zhang

School of Natural Resources: Faculty Publications

Accurate estimates of gross primary production (GPP) for croplands are needed to assess carbon cycle and crop yield. Satellite-based models have been developed to monitor spatial and temporal GPP patterns. However, there are still large uncertainties in estimating cropland GPP. This study compares three light use efficiency (LUE) models (MODIS-GPP, EC-LUE, and VPM) with eddy-covariance measurements at three adjacent AmeriFlux crop sites located near Mead, Nebraska, USA. These sites have different croprotation systems (continuous maize vs. maize and soybean rotated annually) and water management practices (irrigation vs. rainfed). The results reveal several major uncertainties in estimating GPP which need to …

How Climate Change Has Affected The Spatio-Temporal Patterns Of Precipitation And Temperature At Various Time Scales In North Korea, Won-Ho Nam, Eun-Mi Hong, Guillermo A. Baigorria

School of Natural Resources: Faculty Publications

Detecting changes in the spatio-temporal patterns of temperature and precipitation is a prerequisite for developing effective adaptation options and strategies for the future. An effective method for assessing climate change and for providing information to decision makers and stakeholders is needed to implement appropriate adaptation strategies. The objective of this study was to determine whether climate change has caused spatio-temporal changes in meteorological elements in North Korea. We delineated the spatio-temporal patterns of temperature and precipitation caused by climate change in specific time periods based on statistically significant differences using a statistically robust method. Historical weather data from 27 meteorological …

2015 Interior Least Tern And Piping Plover Monitoring, Research, Management, And Outreach Report For The Lower Platte River, Nebraska, Mary Bomberger Brown, Lauren R. Dinan, Joel G. Jorgensen

School of Natural Resources: Faculty Publications

Abstract:

This document reports on our monitoring, research, management, and outreach activities during the past 12 months (2014–2015). We prepared it to inform our partners, cooperating agencies, funding sources, and other interested parties of our activities and to provide a preliminary summary of our results.

The lower Platte River and its major tributaries provide important nesting and migratory stopover habitat for two bird species of special conservation concern: the state and federally endangered Interior Least Tern (Sternula antillarum athalassos) and threatened Piping Plover (Charadrius melodus). The Tern and Plover Conservation Partnership (TPCP), based at the University …

The Effect Of Weather During Rearing On Morphometric Traits Of Juvenile Cliff Swallows, Erin A. Roche, Mary Bomberger Brown, Charles R. Brown

School of Natural Resources: Faculty Publications

Episodes of food deprivation may change how nestling birds allocate energy to the growth of skeletal and feather morphological traits during development. Cliff swallows (Petrochelidon pyrrhonota) are colonial, insectivorous birds that regu­larly experience brief periods of severe weather–induced food deprivation during the nesting season which may affect offspring development. We investigated how annual variation in timing of rearing and weather were associated with length of wing and tail, skeletal traits, and body mass in juvenile cliff swallows reared in southwestern Nebraska during 2001–2006. As predicted under conditions of food deprivation, nestling skeletal and feather measurements were generally smaller …

Juvenile Green Sturgeon (Acipenser Medirostris) And White Sturgeon (Acipenser Transmontanus) Behavior Near Water-Diversion Fish Screens: Experiments In A Laboratory Swimming Fume, Jamilynn B. Poletto, Dennis E. Cocherell, Natalie Ho, Joseph J. Cech Jr., A. Peter Klimley, Nann A. Fangue

School of Natural Resources: Faculty Publications

Water diversions that extract fresh water for urban, industrial, and agricultural uses, as well as export to southern California, are prevalent throughout the Sacramento–San Joaquin watershed. Many water diversions are fitted with fish-exclusion screens designed to prevent fish from entrainment (i.e., being drawn in). The impact of fish screens on the behavior of migrating juvenile fishes remains largely unknown, especially for threatened species such as sturgeon. We placed individual juvenile green (Acipenser medirostris) or white (Acipenser transmontanus) sturgeon in a laboratory swimming flume in the presence of standard fish screens (2 mm bar spacing) at two …

Patch-Burn Grazing Effects On Cattle Performance: Research Conducted In A Working Landscape, Stephen L. Winter, Samuel D. Fuhlendorf, Mark Goes

School of Natural Resources: Faculty Publications

• Patch-burn grazing is a range management strategy that might be able to simultaneously optimize livestock production objectives and wildlife habitat objectives.

• We compared patch-burn grazing to a traditional range management strategy in multiple pastures, representing a variety of land ownership and management histories, dispersed across a relatively large geographic area. Our results likely represent what land managers could expect if they adopted patch-burn grazing in similar situations.

• We found that cattle performance in pastures managed with patch-burn grazing did not differ from that found in pastures managed with a traditional range management strategy. This suggests that land …

Variation In Age Composition Among Colony Sizes In Cliff Swallows, Charles R. Brown, Erin A. Roche, Mary Bomberger Brown

School of Natural Resources: Faculty Publications

Variation in group size is characteristic of most social species. The extent to which individuals sort among group sizes based on age may yield insight into why groups vary in size and the age-specific costs and benefits of different social environments. We investigated the age composition of Cliff Swallow (Petrochelidon pyrrhonota) colonies of different sizes over 18 yr at a long-term study site in western Nebraska, USA. Using years elapsed since banding as a relative measure of age for over 194,000 birds, we found that the proportion of age-class-1 swallows (birds banded as nestlings or juveniles or adults in the …

2014 Interior Least Tern And Piping Plover Monitoring, Research, Management, And Outreach Report For The Lower Platte River, Nebraska, Mary Bomberger Brown, Joel G. Jorgensen, Lauren R. Dinan

School of Natural Resources: Faculty Publications

This document reports on our monitoring, research, management, and outreach activities during the past 12 months (2013–2014). We prepared it to inform our partners, cooperating agencies, funding sources, and other interested parties of our activities and to provide a preliminary summary of our results.

The lower Platte River and its major tributaries provide important nesting and migratory stopover habitat for two bird species of special conservation concern: the state and federally endangered Interior Least Tern (Sternula antillarum athalassos) and threatened Piping Plover (Charadrius melodus). The Tern and Plover Conservation Partnership (TPCP), based at the University of …

Inconsistent Outcomes Of Heterogeneity-Based Management Underscore Importance Of Matching Evaluation To Conservation Objectives, Devan Allen Mcgranahan, David M. Engle, Samuel D. Fuhlendorf, Stephen L. Winter, James R. Miller, Diane M. Debinski

School of Natural Resources: Faculty Publications

Conservation policy often incentivizes managers of human-impacted areas to create landscape heterogeneity to maximize biodiversity. In rangeland, patchy disturbance regimes create landscape heterogeneity (patch contrast), but outcomes of heterogeneity-based management are rarely tested for a universal response. We analyzed four habitat variables—vegetation structure, plant functional group composition, litter cover, and bare ground—from five experimental rangelands in Oklahoma and Iowa, USA. We tested for response consistency to heterogeneity-based management across and within locations. We calculated effect sizes for each variable to compare patch contrast on pastures managed for heterogeneity (patch burn-grazing) and pastures managed for homogeneity (grazing with homogeneous fire regimes). …

Seasonal Fires, Bison Grazing, And The Tallgrass Prairie Forb Arnoglossum Plantagineum Raf., Stephen L. Winter, Karen R. Hickman, Carla L. Goad, Samuel D. Fuhlendorf, Mark S. Gregory

School of Natural Resources: Faculty Publications

Fire and grazing can interact to affect the structure and composition of vegetation communities in a manner that may differ from the effects of fire or grazing that occurs in isolation of the other. In order to better understand the effects of a fire-grazing interaction at the level of an individual plant species, we studied the response of a perennial tallgrass prairie forb, Arnoglossum plantagineum Raf., to the interaction of spring and summer fires with grazing by bison (Bison bison L.). During one field season (2006), we collected data in areas that had been treated with summer fires while …

Fluctuating Viability Selection On Morphology Of Cliff Swallows Is Driven By Climate, Charles R. Brown, Mary Bomberger Brown, Erin A. Roche

School of Natural Resources: Faculty Publications

The extent to which fluctuating selection can maintain evolutionary stasis in most populations remains an unresolved question in evolutionary biology. Climate has been hypothesized to drive reversals in the direction of selection among different time periods and may also be responsible for intense episodic selection caused by rare weather events. We measured viability selection associated with morphological traits in cliff swallows (Petrochelidon pyrrhonota) in western Nebraska, USA, over a 14-year period following a rare climatic event. We used mark-recapture to estimate the annual apparent survival of over 26 000 individuals whose wing, tail, tarsus, and bill had been …

Where Has All The Road Kill Gone?, Charles R. Brown, Mary Bomberger Brown

School of Natural Resources: Faculty Publications

An estimated 80 million birds are killed by colliding with vehicles on U.S. roads each year [1], and millions more die annually in Europe [2] and elsewhere. Losses to vehicles are a serious problem for which various changes in roadway design and maintenance have been proposed [3]. Yet, given the magnitude of the mortality reported for some species [4], we might expect natural selection to favor individuals that either learn to avoid cars or that have other traits making them less likely to collide with vehicles. If so, the frequency of road kill should decline over time. No information is …

Behavioural Salinity Preferences Of Juvenile Green Sturgeon Acipenser Medirostris Acclimated To Fresh Water And Full-Strength Salt Water, J. B. Poletto, D. E. Cocherell, A. P. Klimley, J. J. Cech Jr., N. A. Fangue

School of Natural Resources: Faculty Publications

To quantify the salinity preference of juvenile green sturgeon Acipenser medirostris, two groups of A. medirostris [140 days post hatch (dph); total length (L_T) 38.0–52.5 cm] were acclimated to either near fresh water (mean ± S.E. salinity = 3.2 ± 0.6) or full-strength salt water (34.1 ± 1.2) over 8 weeks. Following acclimation, the two groups were divided into experimental and control groups, where experimental A. medirostris from both freshwater and saltwater acclimations were individually introduced (200–220 dph) into a rectangular salinity-preference flume (maximum salinity gradient: 5–33). Control A. medirostris were presented with only their acclimation …

Overwinter Mortality Of Sympatric Juvenile Bluegill And Yellow Perch In Mid-Temperate Prairie Lakes, Jeffrey C. Jolley, Mark A. Kaemingk, David W. Willis, Richard S. Holland

School of Natural Resources: Faculty Publications

Substantial mortality can occur in age-0 fish populations during their first year of life, especially in winter; this can potentially influence overall recruitment into the adult population. As such, we compared relative abundances between fall and spring catches of sympatric juvenile bluegill Lepomis macrochirus Rafinesque and yellow perch Perca flavescens (Mitchill) to evaluate the magnitude of overwinter mortality across locations (five lakes for two years) and through time (one lake for six years). In addition, we compared both quantile-quantile and increment plots, based on length-frequency histograms from fall- and spring-caught cohorts from 2004 to 2010, to determine if mortality was …

Atrazine And Nitrate In Public Drinking Water Supplies And Non-Hodgkin Lymphoma In Nebraska, Usa, Martha G. Rhoades, Jane L. Meza, Cheryl L. Beseler, Patrick J. Shea, Andy Kahle, Julie M. Vose, Kent M. Eskridge, Roy F. Spalding

School of Natural Resources: Faculty Publications

A secondary analysis of 1999–2002 Nebraska case-control data was conducted to assess the risk of non-Hodgkin lymphoma (NHL) associated with exposure to nitrate- and atrazine-contaminated drinking water. Water chemistry data were collected and weighted by well contribution and proximity of residence to water supply, followed by logistic regression to determine odds ratios (OR) and 95% confidence intervals (CI). We found no association between NHL risk and exposure to drinking water containing atrazine or nitrate alone. Risk associated with the interaction of nitrate and atrazine in drinking water was elevated (OR, 2.5; CI, 1.0–6.2). Risk of indolent B-cell lymphoma was higher …