Life Sciences Commons^™

The Impact Of Heat Load On Cattle, Angela M. Lees, Veerasamy Sejian, Andrea L. Wallage, Cameron C. Steel, Terry L. Mader, Jarrod C. Lees, John B. Gaughan

Department of Animal Science: Faculty Publications

Heat stress and cold stress have a negative influence on cattle welfare and productivity. There have been some studies investigating the influence of cold stress on cattle, however the emphasis within this review is the influence of heat stress on cattle. The impact of hot weather on cattle is of increasing importance due to the changing global environment. Heat stress is a worldwide phenomenon that is associated with reduced animal productivity and welfare, particularly during the summer months. Animal responses to their thermal environment are extremely varied, however, it is clear that the thermal environment influences the health, productivity, and …

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

USDA Forest Service / UNL Faculty Publications

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

Environmental Effects Are Stronger Than Human Effects On Mammalian Predator-Prey Relationships In Arid Australian Ecosystems, Benjamin L. Allen, Alana Fawcett, Alison Anker, Richard M. Engeman, Allan Lisle, Luke K.-P. Leung

USDA Wildlife Services: Staff Publications

Climate (drought, rainfall), geology (habitat availability), land use change (provision of artificial waterpoints, introduction of livestock), invasive species (competition, predation), and direct human intervention (lethal control of top-predators) have each been identified as processes driving the sustainability of threatened fauna populations. We used a systematic combination of empirical observational studies and experimental manipulations to comprehensively evaluate the effects of these process on a model endangered rodent, dusky hopping-mice (Notomys fuscus). We established a large manipulative experiment in arid Australia, and collected information from relative abundance indices, camera traps, GPS-collared dingoes (Canis familiaris) and dingo scats, along …

Development Of On-Shore Behavior Among Polar Bears (Ursus Maritimus) In The Southern Beaufort Sea: Inherited Or Learned?, Kate M. Lillie, Eric M. Gese, Todd C. Atwood, Sarah A. Sonsthagen

USDA Wildlife Services: Staff Publications

Polar bears (Ursus maritimus) are experiencing rapid and substantial changes to their environment due to global climate change. Polar bears of the southern Beaufort Sea (SB) have historically spent most of the year on the sea ice. However, recent reports from Alaska indicate that the proportion of the SB subpopulation observed on-shore during late summer and early fall has increased. Our objective was to investigate whether this on-shore behavior has developed through genetic inheritance, asocial learning, or through social learning. From 2010 to 2013, genetic data were collected from SB polar bears in the fall via hair snags …

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, …

Large But Uneven Reduction In Fish Size Across Species In Relation To Changing Sea Temperatures, Itai Van Rijn, Yehezkel Buba, John Delong, Moshe Kiflawi, Jonathan Belmaker

School of Biological Sciences: Faculty Publications

Ectotherms often attain smaller body sizes when they develop at higher temperatures. This phenomenon, known as the temperature size rule, has important consequences for global fisheries, whereby ocean warming is predicted to result in smaller fish and reduced biomass. However, the generality of this phenomenon and the mechanisms that drive it in natural populations remain unresolved. In this study we document the maximal size of 74 fish species along a steep temperature gradient in the Mediterranean Sea and find strong support for the temperature size rule. Importantly, we additionally find that size reduction in active fish species is dramatically larger …

Long-Term Sandhills Prairie Responses To Precipitation, Temperature, And Cattle Stocking Rate, John A. Guretzky, Cheryl Dunn, Heidi L. Hillhouse

Department of Agronomy and Horticulture: Faculty Publications

Understanding of Sandhills prairie, the most expansive sand dune region stabilized by perennial grasses in the Western Hemisphere, is limited by lack of long-term vegetation data. We used a 26-year dataset to evaluate Sandhills prairie responses to yearto- year variation in precipitation, temperature, and cattle stocking rate. Basal cover, a measurement that is constant seasonally and used to detect long-term changes in bunchgrass vegetation, was measured in 38–40 permanent plots positioned along four transects spanning 769 ha from 1979 to 2007. Across this period, total basal cover averaged 2.4 % and was dominated by warm-season grasses (81.1 %). Schizachyrium scoparium …

A Review Of Fall Sandhill Crane Migration Through Indiana, Allisyn-Marie T. Y. Gillet

Proceedings of the North American Crane Workshop

The Indiana Division of Fish and Wildlife conducts surveys from October to December to collect long-term data on greater sandhill cranes (Grus canadensis tabida). Results from these censuses contribute to a fall index of the Eastern Population, which informs wildlife management decisions and research priorities. Recent findings from the annual U. S. Fish and Wildlife Service Fall Sandhill Crane Migration Survey demonstrate a decline in the number of cranes observed at fall staging areas throughout Indiana since 1979. However, nationwide data exhibit a trend of population increase. I provide evidence to show that the apparent decline in the …

Is The Relationship Between Mast-Seeding And Weather In Oaks Related To Their Life-History Or Phylogeny?, Walter D. Koenig, Reyes Alejano, Maria Dolores Carbonero, Pilar Fernández-Rebollo, Johannes Knops, Teodoro Marañón, Carmen M. Padilla-Díaz, Ian S. Pearse, Ignacio M. Pérez-Ramos, Javier Vázquez-Piqué, Mario B. Pesendorfer

School of Biological Sciences: Faculty Publications

Although the functional basis of variable and synchronous seed production (masting behavior) has been extensively investigated, only recently has attention been focused on the proximate mechanisms driving this phenomenon. We analyzed the relationship between weather and acorn production in 15 species of oaks (genus Quercus) from three geographic regions on two continents, with the goals of determining the extent to which similar sets of weather factors affect masting behavior across species and to explore the ecological basis for the similarities detected. Lag-1 temporal autocorrelations were predominantly negative, supporting the hypothesis that stored resources play a role in masting behavior …

Invasion During Extreme Weather: Success And Failure In A Temperate Perennial Grassland, James C. Han, Stephen L. Young

West Central Research and Extension Center, North Platte

Invasive and native plant species compete for resources in similar pools, with disturbances often favoring the invader. Yet, increased climate variability may be shifting the competitive edge back toward the natives. We conducted field studies in perennial grasslands to determine the effects of clipping and drought on resource availability (light and moisture) and subsequent establishment of Carduus nutans. We measured light penetration and soil moisture content in C. nutans monoculture, clipped and non clipped grassland with C. nutans, and bare ground control plots. We also tracked phenology of the invader and grasses. Our studies revealed that light was a limiting …

Body Size Distributions Signal A Regime Shift In A Lake Ecosystem, Trisha L. Spanbauer, Craig R. Allen, David G. Angeler, Tarsha Eason, Sherilyn C. Fritz, Ahjond S. Garmestani, Kirsty L. Nash, Jeffery R. Stone, Craig A. Stow, Shana M. Sundstrom

Nebraska Cooperative Fish and Wildlife Research Unit: Staff Publications

Communities of organisms, from mammals to microorganisms, have discontinuous distributions of body size. This pattern of size structuring is a conservative trait of community organization and is a product of processes that occur at multiple spatial and temporal scales. In this study, we assessed whether body size patterns serve as an indicator of a threshold between alternative regimes. Over the past 7000 years, the biological communities of Foy Lake (Montana, USA) have undergone a major regime shift owing to climate change. We used a palaeoecological record of diatom communities to estimate diatom sizes, and then analysed the discontinuous distribution of …

Riparian Trees And Aridland Streams Of The Southwestern United States: An Assessment Of The Past, Present, And Future, D. Max Smith, Deborah M. Finch

USDA Forest Service / UNL Faculty Publications

Riparian ecosystems are vital components of aridlands within the southwestern United States. Historically, surface flows influenced population dynamics of native riparian trees. Many southwestern streams has been altered by regulation, however, and will be further affected by greenhouse warming. Our analysis of stream gage data revealed that decreases in volume of annual discharge and mean peak discharge and a shift to earlier peak discharge will occur in the Southern Rockies region of Colorado, New Mexico, and Utah. These changes will likely decrease rates of reproduction and survival of cottonwood (Populus fremontii and Populus deltoides ssp. wislizenii), Goodding's willow …

A Forest Vulnerability Index Based On Drought And High Temperatures, David Mildrexler, Zhiqiang Yang, Warren B. Cohen, David M. Bell

USDA Forest Service / UNL Faculty Publications

Increasing forest stress and tree mortality has been directly linked to combinations of drought and high temperatures. The climatic changes expected during the next decades – large increases in mean temperature, increased heat waves, and significant long-term regional drying in the western USA – will likely increase chronic forest stress and mortality. The aim of this research is to develop and apply a new forest vulnerability index (FVI) associated with drought and high temperatures across the Pacific Northwest region (PNW; Oregon and Washington) of the USA during the MODIS Aqua era (since 2003). Our technique incorporates the alterations to canopy …

Contributing Factors For Drought In United States Forest Ecosystems Under Projected Future Climates And Their Uncertainty, Charles H. Luce, James M. Vose, Neil Pederson, John Campbell, Connie Millar, Patrick Kormos, Ross Woods

USDA Forest Service / UNL Faculty Publications

Observations of increasing global forest die-off related to drought are leading to more questions about potential increases in drought occurrence, severity, and ecological consequence in the future. Dry soils and warm temperatures interact to affect trees during drought; so understanding shifting risks requires some understanding of changes in both temperature and precipitation. Unfortunately, strong precipitation uncertainties in climate models yield substantial uncertainty in projections of drought occurrence. We argue that disambiguation of drought effects into temperature and precipitation-mediated processes can alleviate some of the implied uncertainty. In particular, the disambiguation can clarify geographic diversity in forest sensitivity to multifarious drivers …

Simulating Long-Term Impacts Of Cover Crops And Climate Change On Crop Production And Environmental Outcomes In The Midwestern United States, Andrea D. Basche, Sotririos V. Archontoulis, Thomas C. Kaspar, Dan B. Jaynes, Timothy B. Parkin, Fernando E. Miguez

Department of Agronomy and Horticulture: Faculty Publications

It is critical to evaluate conservation practices that protect soil and water resources from climate change in the Midwestern United States, a region that produces one-quarter of the world’s soybeans and one-third of the world’s maize. An over-winter cover crop in a maize–soybean rotation offers multiple potential benefits that can reduce the impacts of higher temperatures and more variable rainfall; some of the anticipated changes for the Midwest. In this experiment we used the Agricultural Production Systems sIMulator (APSIM) to understand how winter rye cover crops impact crop production and environmental outcomes, given future climate change. We first tested APSIM …

At Home And At Large In The Great Plains: Essays And Memories, Paul A. Johnsgard

Zea E-Books Collection

This volume presents fourteen essays (some updated) that originally appeared in Prairie Fire, a monthly free newspaper that for seven years (as of 2015) has carried important messages of social, environmental, and economic issues in a mature and nonpartisan manner to tens of thousands of residents of Nebraska, western Iowa, eastern Colorado, and southern South Dakota, and by mail to subscribers in the rest of the world. These essays discuss the North American east-west ecological boundaries, spring migration events, birds at the bird feeder, feathered survivors of a glacial past, the threatened sharp-tailed grouse of Nebraska and South Dakota, and …

Global Warming And Population Responses Among Great Plains Birds, Paul A. Johnsgard

Zea E-Books Collection

Based on an analysis of 47 years (1967–2014) of Audubon Christmas Bird Counts (CBC), evidence for population changes and shifts in early winter (late December) ranges of nearly 150 species of birds in the Great Plains states is summarized, a region defined as including the Dakotas, Nebraska, Kansas, Oklahoma, and the Texas panhandle. The rationale for this study had its origins in Terry Root’s 1988 Atlas of North American Wintering Birds. Root’s landmark study provided a baseline for evaluating the nationwide winter distributions of 253 North American birds in the mid-20th century, using data from the National Audubon Society’s …

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 …

Evolution In Action: Climate Change, Biodiversity Dynamics And Emerging Infectious Disease, Eric P. Hoberg, Daniel R. Brooks

Harold W. Manter Laboratory of Parasitology: Faculty and Staff Publications

Climatological variation and ecological perturbation have been pervasive drivers of faunal assembly, structure and diversification for parasites and pathogens through recurrent events of geographical and host colonization at varying spatial and temporal scales of Earth history. Episodic shifts in climate and environmental settings, in conjunction with ecological mechanisms and host switching, are often critical determinants of parasite diversification, a view counter to more than a century of coevolutionary thinking about the nature of complex host–parasite assemblages. Parasites are resource specialists with restricted host ranges, yet shifts onto relatively unrelated hosts are common during phylogenetic diversification of parasite lineages and directly …

Effects Of Drought On Forests And Rangelands In The United States: A Comprehensive Science Synthesis, James M. Vose, James S. Clark, Charles H. Luce, Toral Patel-Weynand

USDA Forest Service / UNL Faculty Publications

This assessment provides input to the reauthorized National Integrated Drought Information System (NIDIS) and the National Climate Assessment (NCA), and it establishes the scientific foundation needed to manage for drought resilience and adaptation. Focal areas include drought characterization; drought impacts on forest processes and disturbances such as insect outbreaks and wildfire; and consequences on forest and rangeland values. Drought can be a severe natural disaster with substantial social and economic consequences. Drought becomes most obvious when large-scale changes are observed; however, even moderate drought can have long-lasting impacts on the structure and function of forests and rangelands without these obvious …

Case Study: Producer Concerns And Perceptions Regarding The Effect Of Methane On Cattle Production And The Environment: A Survey Of Nebraska Producers, B. M. Boyd, A. Jones, Lisa Franzen-Castle, K. Jenkins, Richard J. Rasby, Matt K. Luebbe, Richard R. Stowell, Samodha C. Fernando, Galen E. Erickson

Department of Animal Science: Faculty Publications

Enteric methane production from cattle and its effect on climate change has been a topic of debate. Multiple studies have explored methods to reduce cattle enteric methane production while simultaneously improving performance. However, most strategies developed have not been widely implemented by cattle producers. Knowledge of producer concerns and perceptions on methane production from cattle and its effect on the environment may be limited. Therefore, the objectives of this survey were to determine what Nebraska producers know about methane production by cattle and how it affects performance and to determine whether different age groups, regions of Nebraska, and production size …

On Underestimation Of Global Vulnerability To Tree Mortality And Forest Die-Off From Hotter Drought In The Anthropocene, Craig D. Allen, David D. Breshears, Nate G. Mcdowell

United States Geological Survey: Staff Publications

Patterns, mechanisms, projections, and consequences of tree mortality and associated broadscale forest die-off due to drought accompanied by warmer temperatures—‘‘hotter drought’’, an emerging characteristic of the Anthropocene—are the focus of rapidly expanding literature. Despite recent observational, experimental, and modeling studies suggesting increased vulnerability of trees to hotter drought and associated pests and pathogens, substantial debate remains among research, management and policy-making communities regarding future tree mortality risks. We summarize key mortalityrelevant findings, differentiating between those implying lesser versus greater levels of vulnerability. Evidence suggesting lesser vulnerability includes forest benefits of elevated [CO2] and increased water-use efficiency; observed and modeled increases …

Breeding Time In A Migratory Songbird Is Predicted By Drought Severity And Group Size, Charles R. Brown, Mary Bomberger Brown

School of Natural Resources: Faculty Publications

Global climate change is altering the breeding phenology of many organisms, and one reported consequence of warmer average temperatures is earlier breeding times in migratory songbirds of north temperate latitudes. Less studied are the potential interactions between earlier breeding and social behavior in colonial species. We investigated how breeding time, as measured by colony initiation dates across the entire summer, in Cliff Swallows (Petrochelidon pyrrhonota) of southwestern Nebraska, USA, changed over a 30-year period and could be predicted by climatic variables, year, and colony size. Mean colony initiation date became earlier over the study, with variation best predicted …

Ecotypes Of An Ecologically Dominant Prairie Grass (Andropogon Gerardii) Exhibit Genetic Divergence Across The U.S. Midwest Grasslands’ Environmental Gradient, Miranda M. Grey, Paul St. Amand, Nora M. Bello, Matthew B. Galliart, Mary Knapp, Karen A. Garrett, Theodore J. Morgan, Sarah G. Baer, Brian R. Maricle, Eduard D. Akhunov, Loretta C. Johnson

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

Big bluestem (Andropogon gerardii) is an ecologically dominant grass with wide distribution across the environmental gradient of U.S. Midwest grasslands. This system offers an ideal natural laboratory to study population divergence and adaptation in spatially varying climates.

Objectives were to: (i) characterize neutral genetic diversity and structure within and among three regional ecotypes derived from 11 prairies across the U.S. Midwest environmental gradient, (ii) distinguish between the relative roles of isolation by distance (IBD) vs. isolation by environment (IBE) on ecotype divergence, (iii) identify outlier loci under selection and (iv) assess the association between outlier loci and climate.

Using two …

Finding Them Before They Find Us: Informatics, Parasites, And Environments In Accelerating Climate Change, Daniel R. Brooks, Eric P. Hoberg, Walter A. Boeger, Scott Lyell Gardner, Kurt E. Galbreath, David Herczeg, Hugo H. Mejía-Madrid, S. Elizabeth Rácz, Altangerel Tsogtsaikhan Dursahinhan

Harold W. Manter Laboratory of Parasitology: Faculty and Staff Publications

Parasites are agents of disease in humans, livestock, crops, and wildlife and are powerful representations of the ecological and historical context of the diseases they cause. Recognizing a nexus of professional opportunities and global public need, we gathered at the Cedar Point Biological Station of the University of Nebraska in September 2012 to formulate a cooperative and broad platform for providing essential information about the evolution, ecology, and epidemiology of parasites across host groups, parasite groups, geographical regions, and ecosystem types. A general protocol, documentation–assessment–monitoring–action (DAMA), suggests an integrated proposal to build a proactive capacity to understand, anticipate, and respond …

Changing Forest Water Yields In Response To Climate Warming: Results From Long-Term Experimental Watershed Sites Across North America, Irena F. Creed, Adam T. Spargo, Julia A. Jones, Jim M. Buttle, Mary B. Adams, Fred D. Beall, Eric G. Booth, John L. Campbell, Dave Clow, Kelly Elder, Mark B. Green, Nancy B. Grimm, Chelcy Miniat, Patricia Ramlal, Amartya Saha, Stephen Sebestyen, Dave Spittlehouse, Shannon Sterling, Mark W. Williams, Rita Wrinkler, Huaxia Yao

USDA Forest Service / UNL Faculty Publications

Climate warming is projected to affect forest water yields but the effects are expected to vary. We investigated how forest type and age affect water yield resilience to climate warming. To answer this question, we examined the variability in historical water yields at long-term experimental catchments across Canada and the United States over 5-year cool and warm periods. Using the theoretical framework of the Budyko curve, we calculated the effects of climate warming on the annual partitioning of precipitation (P) into evapotranspiration (ET) and water yield. Deviation (d) was defined as a catchment’s change in actual ET divided by P …

Drought-Induced Woody Plant Mortality In An Encroached Semi-Arid Savanna Depends On Topoedaphic Factors And Land Management, Dirac L. Twidwell Jr, Carissa L. Wonkka, Charles A. Taylor, Chris B. Zou, Jeremiah J. Twidwell, William E. Rogers

Department of Agronomy and Horticulture: Faculty Publications

Questions: How do recent patterns of drought-induced woody plant mortality in Texas semi-arid savanna compare to the extended drought of the 1950s? Does the relative composition of the woody plant community shift ubiquitously across the landscape following woody plant mortality and dieback or are shifts dependent on differences among species, soils, land use and plant demography?

Location: Texas Agrilife Research Station, Sonora, Texas, USA (30.1° N 100.3° W).

Methods: Following an exceptional drought from 1951 to 1957, a study was conducted to quantify rates of mortality for various woody plant species. In 2011, we repeated this study within three long-term …

Predicted Wildlife Disease-Related Climate Change Impacts Of Specific Concern To Usda Aphis Wildlife Services, Timothy P. Algeo, Richard B. Chipman, Dennis Slate, Jerome E. Freier, Thomas J. Deliberto

USDA Wildlife Services: Staff Publications

USDA APHISWildlife Services plans for and responds to a variety of exigencies such as wildlife hazards to aircraft, disease emergence from wildlife translocations, oral rabies vaccine barrier compromises, and extreme weather events. These are often collaborative efforts with state and federal agencies and others. Climate change based in part on fossil fuel use and methane gas emissions has predictable as well as unknown consequences. As a federal leader in wildlife disease research and management, it is incumbent upon Wildlife Services to be current with the scientific literature; assess potential impacts and wildlife disease management intervention needs from predicted climate change …

Critical Research Needs For Successful Food Systems Adaptation To Climate Change, Michelle Miller, Molly Anderson, Charles A. Francis, Chad Kruger, Carol Barford, Jacob Park, Brent H. Mccown

Department of Agronomy and Horticulture: Faculty Publications

There is a growing sense of the fragility of agricultural production in the Global North and South and of increasing risks to food security, as scientific observations confirm significant changes in the Gulf Stream, polar ice, atmospheric CO₂, methane release, and other measures of climate change. This sense is heightened as each of us experiences extreme weather, such as the increasing frequency of droughts, floods, unseasonal temperatures, and erratic seasonality. The central research challenge before us is how global, national, regional, and local food systems may adapt to accelerating climate change stresses and uncertainties to ensure the availability, …

Diversity And Distribution Of Mongolian Fish: Recent State, Trends And Studies, Yuri Dgebuadze, Bud Mendsaikhan, Ayurin Dulmaa

Erforschung biologischer Ressourcen der Mongolei / Exploration into the Biological Resources of Mongolia, ISSN 0440-1298

The studies in recent years (2000-2011) have allowed to make more precise the list and ranges of Mongolian fish. This is connected with new findings as well as the continuing process of invasion of alien species. Climate change and increase of human impact transformed ranges and local distribution of fish during last 30 years. Bias on ratio of ecological guilds, number of pathological findings are increasing, and declining of local diversity, rate of growth and fecundity of many species of fish are observed. In the course of long-term observation was confirmed periodically drying of waters of the Central Asian Lake …