Digital Commons Network^™

Rqgis: Integrating R With Qgis For Statistical Geocomputing, Jannes Muenchow, Patrick Schratz, Alexander Brenning

The R Journal

Integrating R with Geographic Information Systems (GIS) extends R’s statistical capabilities with numerous geoprocessing and data handling tools available in a GIS. QGIS is one of the most popular open-source GIS, and it furthermore integrates other GIS programs such as the System for Automated Geoscientific Analyses (SAGA) GIS and the Geographic Resources Analysis Support System (GRASS) GIS within a single software environment. This and its QGIS Python API makes it a perfect candidate for console-based geoprocessing. By establishing an interface, the R package RQGIS makes it possible to use QGIS as a geoprocessing workhorse from within R. Compared to other …

Mode And Rate Of Evolution Of Haemosporidian Mitochondrial Genomes: Timing The Radiation Of Avian Parasites, M. Andreína Pacheco, Nubia E. Matta, Gediminas Valkiūnas, Patricia G. Parker, Beatriz Mello, Craig E. Stanley Jr., Miguel Lentino, Maria Alexandra Garcia-Amado, Michael Cranfield, Sergei L. Kosakovsky Pond, Ananias A. Escalante

Harold W. Manter Laboratory of Parasitology: Library Materials

Haemosporidians are a diverse group of vector-borne parasitic protozoa that includes the agents of human malaria; however, most of the described species are found in birds and reptiles. Although our understanding of these parasites’ diversity has expanded by analyses of their mitochondrial genes, there is limited information on these genes’ evolutionary rates. Here, 114 mitochondrial genomes (mtDNA) were studied from species belonging to four genera: Leucocytozoon, Haemoproteus, Hepatocystis, and Plasmodium. Contrary to previous assertions, the mtDNA is phylogenetically informative. The inferred phylogeny showed that, like the genus Plasmodium, the Leucocytozoon and Haemoproteus genera are not monophyletic groups. Although …

Influence Of An Internal Parasite Control On Cattle Grazing Behavior And Production, Jace Stott

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

Six herds of 45 to 90 cow/calf pairs grazing on upland range were used to examine the efficacy of an injectable extended release eprinomectin parasite control on production traits, activity behavior, and efficacy against internal parasitism. In 2016, treatment cows were given a subcutaneous injection of LongRange^tm. In 2017, all cows in the study were treated with a short acting Synanthic^tm treatment and only treatment cows were given an additional LongRange^tm treatment. In both 2016 and 2017, fecal egg counts were significantly lower (P < 0.05) in eprinomectin treated cows compared to control cows. Calf gains were 4.8 kg and 8.7 kg greater (P < 0.1) for the calves of dams treated with eprinomectin compared to calves of control cows in 2016 and 2017, respectively. Activity characteristics of cattle were inconclusive, with treated cows having lower (P < 0.01) grazing and traveling times compared to control cows in 2016, and more (P < 0.01) grazing and traveling in 2017.

Differences in grazing behaviors based on time within pasture at different times …

An Unparalleled Opportunity For An Important Ecological Study, L. David Mech, Shannon M. Barber-Meyer, Juan Carlos Blanco, Luigi Boitani, Ludwig Carbyn, Glenn Delgiudice, Steven H. Fritts, Djuro Huber, Olof Liberg, Brent Patterson, Richard R. Thiel

United States Geological Survey, Northern Prairie Wildlife Research Center: Publications

Wolves (Canis lupus) and moose (Alces americanus) have been studied since 1958 on 540-squarekilometer Isle Royale National Park, in Lake Superior. Wolves arrived there across the ice around 1949, and the population once increased to about 50, averaging about 25 annually (Mech 1966, Jordan et al. 1967, Vucetich and Peterson 2009). However, for various reasons, wolf numbers there have now dwindled to 2 nonbreeders, and the US National Park Service has proposed reintroducing 20–30 wolves over 3 years (National Park Service 2016). This situation offers an unparalleled opportunity to promote science-based management of this unique national park. …

Information In The Ecosystem: Against The “Information Ecosystem”, Timothy B. Norris, Todd Suomela

Copyright, Fair Use, Scholarly Communication, etc.

The “information ecosystem” metaphor is widely used in academic libraries and has become nearly ubiquitous when speaking of the information systems that support scholarly communication and varied forms of data sharing and publication. The trending use of this language arises from non-academic applications — for example in big data (the Hadoop ecosystem) or software development (the node.js ecosystem) — and there remains little critical examination of the use of this metaphor. Indeed, the definition of ecosystem as the set of relations between living organisms and their surrounding non-living environment is apparently not directly a part of the metaphor. This paper …

An Economic Analysis Of A Total Allowable Catch-Individual Transferable Quota System In A Developing Country Heterogeneous Fishery: An Application To The Digha Fishery In West Bengal, India, Nadeeka Weerasekara

Department of Agricultural Economics: Dissertations, Theses, and Student Research

This thesis contributes to the literature of economics of small-scale fishery communities and fishery management in developing nations. In the first section we review literature on state of the fishery resource and the livelihoods in the globe and performance of fishery management systems in developing and developed countries. Second section discusses the results of an empirical study on the economics of subsistence fishers in Digha-Shankarpur in Eastern India. Results of the empirical study shows by-catch by the trawlers leads to the depletion of target fish stock of the subsistence fishers. Underutilization of the capacity by the subsistence fishers due to …

Center For Grassland Studies, Volume 23, Issue 2, Summer 2017

Center for Grassland Studies: Newsletters

2017 Nebraska Grazing Conference

Grazing Livestock Systems Internship

2017 Fall Seminar Series & Leu Lecture

PGA Golf Management Club Officers Selected for 2017-2018

Workshop … The Changing Face of Engagement: Reaching the 21st Century Forest and Rangeland Client

Congratulations, Graduates!

CGS Alumni Updates

2017 Nike Golf Camp

Kudos to PGAM Faculty and Staff

Frank L. and Mary Bruning Honored with First Annual Nebraska Grazing Lands Coalition Lifetime Achievement Award

Roadside Vegetation in Nebraska

Katie Cumming—Grazing Livestock Systems Graduate Research Assistant

An Update on Prairies in the Sky: Green Roofs

Spring Creek Prairie’s Outdoor Dinner Fundraiser

UNL Alum Qualifies for 99th …

Heterogeneity Of Avian Breeding Habitat On Grazing Lands Of The Northern Great Plains, Maggi S. Sliwinski

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

Native rangelands in the Great Plains are largely privately owned and used for beef production. Vegetation heterogeneity is important for maintaining biodiversity, but private land may be more homogenous than desired. My research had two components: 1) to examine whether a variety of grazing strategies created vegetation heterogeneity in a large, intact rangeland, and 2) to understand beef producers’ attitudes about vegetation heterogeneity.

First, I sampled vegetation structure, composition, and bird abundance at multiple plots on eleven management units in Cherry County, Nebraska. Units were managed with commonly used grazing strategies (e.g., short-duration grazing and season-long continuous grazing). I examined …

Common Carp Disrupt Ecosystem Structure And Function Through Middle-Out Effects, Mark A. Kaemingk, Jeffrey C. Jolley, Craig P. Paukert, David W. Willis, Kjetil Henderson, Richard S. Holland, Greg A. Wanner, Mark L. Lindvall

School of Natural Resources: Faculty Publications

Middle-out effects or a combination of top-down and bottom-up processes create many theoretical and empirical challenges in the realm of trophic ecology. We propose using specific autecology or species trait (i.e. behavioural) information to help explain and understand trophic dynamics that may involve complicated and nonunidirectional trophic interactions. The common carp (Cyprinus carpio) served as our model species for whole-lake observational and experimental studies; four trophic levels were measured to assess common carp-mediated middle-out effects across multiple lakes. We hypothesised that common carp could influence aquatic ecosystems through multiple pathways (i.e. abiotic and biotic foraging, early life feeding, nutrient). Both …

Greater Sage-Grouse Population Trends Across Wyoming, David R. Edmunds, Cameron L. Aldridge, Michael S. O'Donnell, Adrian P. Monroe

United States Geological Survey: Staff Publications

The scale at which analyses are performed can have an effect on model results and often one scale does not accurately describe the ecological phenomena of interest (e.g., population trends) for wide-ranging species: yet, most ecological studies are performed at a single, arbitrary scale. To best determine local and regional trends for greater sage-grouse (Centrocercus urophasianus) in Wyoming, USA, we modeled density-independent and -dependent population growth across multiple spatial scales relevant to management and conservation (Core Areas [habitat encompassing approximately 83% of the sage-grouse population on ~24% of surface area in Wyoming], local Working Groups [7 regional areas for …

Balancing Stability And Flexibility In Adaptive Governance: An Analysis Of Tools Available In U.S. Environmental Law, Robin Kundis Craig, Ahjond S. Garmestani, Craig R. Allen, Craig Anthony (Tony) Arnold, Hannah E. Birge, Hannah Birge, Daniel A. Decaro, Alexander K. Fremier, Alexander K. Fremier, Hannah Gosnell, Edella C. Schlager

United States Geological Survey: Staff Publications

Adaptive governance must work “on the ground,” that is, it must operate through structures and procedures that the people it governs perceive to be legitimate and fair, as well as incorporating processes and substantive goals that are effective in allowing social-ecological systems (SESs) to adapt to climate change and other impacts. To address the continuing and accelerating alterations that climate change is bringing to SESs, adaptive governance generally will require more flexibility than prior governance institutions have often allowed. However, to function as good governance, adaptive governance must pay real attention to the problem of how to balance this increased …

Semi-Arid Grassland Bird Responses To Patch-Burn Grazing And Drought, Susan K. Skagen, David J. Augustine, Justin D. Derner

United States Geological Survey: Staff Publications

As grassland birds of central North America experience steep population declines with changes in land use, management of remaining tracts becomes increasingly important for population viability. The integrated use of fire and grazing may enhance vegetation heterogeneity and diversity in breeding birds, but the subsequent effects on reproduction are unknown. We examined the influence of patch-burn grazing management in shortgrass steppe in eastern Colorado on habitat use and reproductive success of 3 grassland bird species, horned lark (Eremophila alpestris), lark bunting (Calamospiza melanocorys), and McCown’s longspur (Rhynchophanes mccownii), at several spatial scales during 2011 …

Climate Dynamics, Invader Fitness, And Ecosystem Resistance In An Invasion-Factor Framework, Stephen L. Young, David R. Clements, Antonio Ditommaso

West Central Research and Extension Center, North Platte

As researchers and land managers increasingly seek to understand plant invasions and the external (climate) and internal (plant genetics) conditions that govern the process, new insight is helping to answer the elusive question of what makes some invasions successful and others not. Plant invasion success or failure is based on a combination of evolutionary and ecological processes. Abiotic (e.g., climate) and biotic (e.g., plant competition) conditions in the environment and plant genetics (e.g., fitness) combine in either decreasing or increasing invasion, yet it has proven challenging to know exactly which of these conditions leads to success for a given species, …

Population Structure And Genetic Diversity Of Bromus Tectorum Within The Small Grain Production Region Of The Pacific Northwest, Nevin C. Lawrence, Amber L. Hauvermale, Amit Dhingra, Ian C. Burke

Department of Agronomy and Horticulture: Faculty Publications

Bromus tectorum L. is an invasive winter annual grass naturalized across the United States. Numerous studies have investigated B. tectorum population structure and genetics in the context of B. tectorum as an ecological invader of natural areas and rangeland. Despite the wealth of information regarding B. tectorum, previous studies have not focused on, or made comparisons to, B. tectorum as it persists in individual agroecosystems. The objectives of this study were to assess the genetic diversity and structure, the occurrence of generalist and specialist genotypes, and the influence of climate on distribution of B. tectorum sourced exclusively from within …

Balancing Stability And Flexibility In Adaptive Governance: An Analysis Of Tools Available In U.S. Environmental Law, Robin Kundis Craig, Ahjond S. Garmestani, Craig R. Allen, Craig Anthony (Tony) Arnold, Hannah E. Birge, Daniel A. Decaro, Alexander K. Fremier, Hannah Gosnell, Edella Schlager

Nebraska Cooperative Fish and Wildlife Research Unit: Staff Publications

Adaptive governance must work “on the ground,” that is, it must operate through structures and procedures that the people it governs perceive to be legitimate and fair, as well as incorporating processes and substantive goals that are effective in allowing social-ecological systems (SESs) to adapt to climate change and other impacts. To address the continuing and accelerating alterations that climate change is bringing to SESs, adaptive governance generally will require more flexibility than prior governance institutions have often allowed. However, to function as good governance, adaptive governance must pay real attention to the problem of how to balance this increased …

A Bayesian Method For Assessing Multi-Scale Species-Habitat Relationships, Erica F. Stuber, Lutz F. Gruber, Joseph J. Fontaine

Nebraska Cooperative Fish and Wildlife Research Unit: Staff Publications

Context Scientists face several theoretical and methodological challenges in appropriately describing fundamental wildlife-habitat relationships in models. The spatial scales of habitat relationships are often unknown, and are expected to follow a multi-scale hierarchy. Typical frequentist or information theoretic approaches often suffer under collinearity in multiscale studies, fail to converge when models are complex or represent an intractable computational burden when candidate model sets are large.

Objectives Our objective was to implement an automated, Bayesian method for inference on the spatial scales of habitat variables that best predict animal abundance.

Methods We introduce Bayesian latent indicator scale selection (BLISS), a Bayesian …

Evaluating The Influence Of Water Developments On The Demography And Spatial Ecology Of A Rare, Desert-Adapted Carnivore: The Kit Fox (Vulpes Macrotis), Bryan M. Kluever, Eric M. Gese

United States Department of Agriculture Wildlife Services: Staff Publications

Constructing water developments to support anthropogenic activities and particular fauna is pervasive across many arid regions of the globe. Despite their prevalence and a predicted increase as a management and conservation tool, water developments may have complex and unanticipated impacts on wildlife. For example, the addition of water developments to the Great Basin Desert in the western United States may have indirectly contributed to a decrease in distribution and abundance of kit foxes (Vulpes macrotis). From 2010 to 2013, we examined survival, relative abundance, and habitat characteristics of kit foxes in relation to water developments on the U.S. …

Using Publicly Available Data To Quantify Plant–Pollinator Interactions And Evaluate Conservation Seeding Mixes In The Northern Great Plains, Clint R.V. Otto, S. O'Dell, R. B. Bryant, N. H. Euliss Jr., R. M. Bush, Matthew D. Smart

Department of Entomology: Faculty Publications

Concern over declining pollinators has led to multiple conservation initiatives for improving forage for bees in agroecosystems. Using data available through the Pollinator Library (npwrc.usgs.gov/pollinator/), we summarize plant–pollinator interaction data collected from 2012–2015 on lands managed by the U.S. Fish and Wildlife Service and private lands enrolled in U.S. Department of Agriculture conservation programs in eastern North Dakota (ND). Furthermore, we demonstrate how plant–pollinator interaction data from the Pollinator Library and seed cost information can be used to evaluate hypothetical seeding mixes for pollinator habitat enhancements. We summarize records of 314 wild bee and 849 honey bee (Apis mellifera …

Regeneration And Invasion Of Cottonwood Riparian Forest Following Wildfire, Carissa L. Wonkka, Dirac L. Twidwell Jr., Christine H. Bielski, Craig R. Allen, Michael C. Stambaugh

Department of Agronomy and Horticulture: Faculty Publications

Populus deltoides is considered to be a weak resprouter and highly susceptible to wildfire, but few post-wildfire studies have tracked P. deltoides response and resprouting within the Great Plains of North America. Following a wildfire in southwestern Kansas, U.S.A., we surveyed burned and unburned areas of a cottonwood riparian forest along the Cimarron River that included a major understory invader, tamarisk (Tamarix ramosissima Ledeb.). We tested the following hypotheses, which are consistent with the current understanding of P. deltoides response to wildfire in the Great Plains: (1) regeneration of P. deltoides will be low in areas burned by the …

Different Prey Resources Suggest Little Competition Between Non-Native Frogs And Insectivorous Birds Despite Isotopic Niche Overlap, Robyn L. Smith, Karen H. Beard, Aaron B. Shiels

United States Department of Agriculture Wildlife Services: Staff Publications

Non-native amphibians often compete with native amphibians in their introduced range, but their competitive effects on other vertebrates are less well known. The Puerto Rican coqui frog (Eleutherodactylus coqui) has colonized the island of Hawaii, and has been hypothesized to compete with insectivorous birds and bats. To address if the coqui could compete with these vertebrates, we used stable isotope analyses to compare the trophic position and isotopic niche overlap between the coqui, three insectivorous bird species, and the Hawaiian hoary bat. Coquis shared similar trophic position to Hawaii amakihi, Japanese white-eye, and red-billed leiothrix. Coquis were about …

Ontogenetic And Ecological Variation In Invasion Risk Of Brown Treesnakes (Boiga Irregularis) On Guam, Shane R. Siers, Julie A. Savidge, Robert N. Reed

United States Department of Agriculture Wildlife Services: Staff Publications

Size structure within populations of invasive species may have consequences for relative risk at all stages of the invasion process, with implications for management interventions such as interdiction, suppression, and eradication. To assess relative distributions of invasive Brown Treesnakes (Boiga irregularis) among demographic categories of management interest, we undertook the most comprehensive and controlled sampling in > 25 years of research into this ecologically and economically destructive introduced predator. We collected a seasonally-balanced sample of 100 snakes from each of 18 sites, stratified by six habitat types, encompassing the species’ entire extralimital range. Samples indicated significant differences in distributions …

History Of Regulations, Policy, And Research Related To Conflicts Between Blackbirds And People, George M. Linz, Michael L. Avery, Richard A. Dolbeer

United States Department of Agriculture Wildlife Services: Staff Publications

The United States and Canada have invested substantial resources over the past 60 years for developing methods to reduce blackbird (Icteridae) damage to agricultural crops, to manage large winter roosts that create nuisance and public health problems, and to mitigate conflicts with endangered species. It is an indication of the challenging nature of the conflicts with these abundant, highly mobile birds that we are still attempting to improve existing methods and develop new approaches to mitigate the problems. Scientists have tested chemical frightening agents and repellents, mechanical scare devices, bird-resistant sunflowers, decoy crops, habitat management, population management, and cultural modifications …

Can We Save Large Carnivores Without Losing Large Carnivore Science?, Benjamin L. Allen, Lee R. Allen, Henrik Andrén, Guy Ballard, Luigi Boitani, Richard M. Engeman, Peter J. S. Fleming, Adam T. Ford, Peter M. Haswell, Rafal Kowalczyk, John D. C. Linnell, L. David Mech, Daniel M. Parker

United States Department of Agriculture Wildlife Services: Staff Publications

Large carnivores are depicted to shape entire ecosystems through top-down processes. Studies describing these processes are often used to support interventionist wildlife management practices, including carnivore reintroduction or lethal control programs. Unfortunately, there is an increasing tendency to ignore, disregard or devalue fundamental principles of the scientific method when communicating the reliability of current evidence for the ecological roles that large carnivores may play, eroding public confidence in large carnivore science and scientists. Here, we discuss six interrelated issues that currently undermine the reliability of the available literature on the ecological roles of large carnivores: (1) the overall paucity of …

Scavenger Removal Of Bird Carcasses At Simulated Wind Turbines: Does Carcass Type Matter?, Travis L. Devault, Thomas W. Seamans, Kimberly E. Linnell, Dale W. Sparks, James C. Beasley

United States Department of Agriculture Wildlife Services: Staff Publications

Wind energy development can negatively impact bird populations due to bird–turbine collisions. To accurately estimate bird mortality at wind farms, the number of dead birds found under turbines is commonly corrected for carcass removal by scavengers, which is quantified by measuring persistence of experimental carcasses through time. These studies often use domestic birds as surrogates because carcasses of wild birds (e.g., raptors) are difficult to obtain. We assessed scavenger removal of carcasses from five bird species at simulated turbines to determine whether domestic surrogates are scavenged at a different rate than raptors, species of interest for wind turbine mortality. The …

Effective Dose And Persistence Of Rhodamine-B In Wild Pig Vibrissae, Sarah C. Webster, Fred L. Cunningham, John C. Kilgo, Mark A. Vukovich, Olin E. Rhodes Jr., James C. Beasley

United States Department of Agriculture Wildlife Services: Staff Publications

As a result of substantial ecological and economic damage attributed to wild pigs (Sus scrofa), there is international interest in using pharmaceutical baits to control populations. To assess the efficacy and specificity of baiting programs, chemical biomarkers can be used to evaluate uptake of pharmaceutical baits. Rhodamine B (RB) is known to be an effective biomarker in wild pigs. However, significant data gaps exist regarding the minimum effective dosage and persistence of RB in wild pigs. We used a controlled doubleblind study experiment conducted in spring of 2014 on the Savannah River Site, Aiken, South Carolina, USA, wherein …

The Persistence Of Multiple Strains Of Avian Influenza In Live Bird Markets, Amy Pinsent, Kim M. Pepin, Huachen Zhu, Yi Guan, Michael T. White, Steven Riley

United States Department of Agriculture Wildlife Services: Staff Publications

Multiple subtypes of avian influenza (AI) and novel reassortants are frequently isolated from live bird markets (LBMs). However, our understanding of the drivers of persistence of multiple AI subtypes is limited. We propose a stochastic model of AI transmission within an LBM that incorporates market size, turnover rate and the balance of direct versus environmental transmissibility. We investigate the relationship between these factors and the critical community size (CCS) for the persistence of single and multiple AI strains within an LBM. We fit different models of seeding from farms to two-strain surveillance data collected from Shantou, China. For a single …

Key Differences Between Lakes And Reservoirs Modify Climate Signals: A Case For A New Conceptual Model, Nicole M. Hayes, Bridget R. Deemer, Jessica R. Corman, N. Roxanna Razavi, Kristin E. Strock

United States Geological Survey: Staff Publications

Lakes and reservoirs are recognized as important sentinels of climate change, integrating catchment and atmospheric climate change drivers. Climate change conceptual models generally consider lakes and reservoirs together despite the possibility that these systems respond differently to climate-related drivers. Here, we synthesize differences between lake and reservoir characteristics that are likely important for predicting waterbody response to climate change. To better articulate these differences, we revised the energy mass flux framework, a conceptual model for the effects of climate change on lentic ecosystems, to explicitly consider the differential responses of lake versus reservoir ecosystems. The model predicts that catchment and …

Quantile Regression Of Microgeographic Variation In Population Characteristics Of An Invasive Vertebrate Predator, Shane R. Siers, Julie A. Savidge, Robert N. Reed

United States Department of Agriculture Wildlife Services: Staff Publications

Localized ecological conditions have the potential to induce variation in population characteristics such as size distributions and body conditions. The ability to generalize the influence of ecological characteristics on such population traits may be particularly meaningful when those traits influence prospects for successful management interventions. To characterize variability in invasive Brown Treesnake population attributes within and among habitat types, we conducted systematic and seasonally-balanced surveys, collecting 100 snakes from each of 18 sites: three replicates within each of six major habitat types comprising 95% of Guam's geographic expanse. Our study constitutes one of the most comprehensive and controlled samplings of …

Effective Dose And Persistence Of Rhodamine-B In Wild Pig Vibrissae, Sarah C. Webster, Fred L. Cunningham, John C. Kilgo, Mark A. Vukovich, Olin E. Rhodes Jr., James C. Beasley

United States Department of Agriculture Wildlife Services: Staff Publications

As a result of substantial ecological and economic damage attributed to wild pigs (Sus scrofa), there is international interest in using pharmaceutical baits to control populations. To assess the efficacy and specificity of baiting programs, chemical biomarkers can be used to evaluate uptake of pharmaceutical baits. Rhodamine B (RB) is known to be an effective biomarker in wild pigs. However, significant data gaps exist regarding the minimum effective dosage and persistence of RB in wild pigs. We used a controlled doubleblind study experiment conducted in spring of 2014 on the Savannah River Site, Aiken, South Carolina, USA, wherein …

Weighted Distance Based Discriminant Analysis: The R Package Wedibadis, Itziar Irigoien, Francesc Mestres, Concepcion Arenas

The R Journal

The WeDiBaDis package provides a user friendly environment to perform discriminant analysis (supervised classification). WeDiBaDis is an easy to use package addressed to the biological and medical communities, and in general, to researchers interested in applied studies. It can be suitable when the user is interested in the problem of constructing a discriminant rule on the basis of distances between a relatively small number of instances or units of known unbalanced-class membership measured on many (possibly thousands) features of any type. This is a current situation when analyzing genetic biomedical data. This discriminant rule can then be used both, as …