Other Environmental Sciences Commons^™

U.S. Drought Monitor, January 29, 2013, Mark D. Svoboda

United States Agricultural Commodities in Drought Archive

Drought map of U.S. for January 29, 2013 (1/29/13) plus: U.S. crop areas experiencing drought (map), Approximate percentage of crop located in drought, by state (bar graph), Percent of crop area located in drought, past 52 weeks (line graph) for: Hay, Cattle, Winter wheat.

U.S. Drought Monitor, January 22, 2013, Mark D. Svoboda

United States Agricultural Commodities in Drought Archive

Drought map of U.S. for January 22, 2013 (1/22/13) plus: U.S. crop areas experiencing drought (map), Approximate percentage of crop located in drought, by state (bar graph), Percent of crop area located in drought, past 52 weeks (line graph) for: Hay, Cattle, Winter wheat.

U.S. Drought Monitor, January 15, 2013, David Simeral

United States Agricultural Commodities in Drought Archive

Drought map of U.S. for January 15, 2013 (1/15/13) plus: U.S. crop areas experiencing drought (map), Approximate percentage of crop located in drought, by state (bar graph), Percent of crop area located in drought, past 52 weeks (line graph) for: Hay, Cattle, Winter wheat.

U.S. Drought Monitor, January 8, 2013, David Simeral

United States Agricultural Commodities in Drought Archive

Drought map of U.S. for January 8, 2013 (1/8/13) plus: U.S. crop areas experiencing drought (map), Approximate percentage of crop located in drought, by state (bar graph), Percent of crop area located in drought, past 52 weeks (line graph) for: Hay, Cattle, Winter wheat.

Long-Term Agro-Ecosystem Research (Ltar) Network To Establish The Platte River – High Plains Aquifer Ltar, Brian J. Wienhold, Tala Awada

School of Natural Resources: Faculty Publications

The University of Nebraska-Lincoln (UNL), the USDA-ARS Agro-ecosystem Management Research Unit (AMRU) in Lincoln, and Environmental Management Research Unit (EMRU) in Clay Center propose to establish a Long-term Agro-ecosystem Research (LTAR) Network site with a focus on the northern portion of the High Plains Aquifer. Over 95 percent of the water withdrawn from the aquifer is for agricultural use, and – unlike the portion of the aquifer underlying southern Kansas, Oklahoma, and Texas where significant drawdown has occurred – ground water levels have remained relatively stable since 1960. However, this stability might be in jeopardy with projected climate variability and …

The Importance Of Spring And Autumn Atmospheric Conditions For The Evaporation Regime Of Lake Superior, Christopher Spence, P.D. Blanken, John D. Lenters, N. Hedstrom

School of Natural Resources: Faculty Publications

Feedbacks between ice extent and evaporation have long been suspected to be important for Lake Superior evaporation because it is during autumn and winter when latent heat fluxes are highest. Recent direct measurements of evaporation made at the Stannard Rock Lighthouse have provided new information on the physical controls on Lake Superior evaporation, in particular that evaporation can react within hours to days to a change in synoptic conditions. However, the large heat capacity of the lake creates a strong seasonal cycle of energy storage and release. There is a complex interaction among heat storage, evaporation, and ice cover that …

Aspects Of Northern Bobwhite Ecology On South Florida Rangeland., J. A. Martin, W. E. Palmer, Carroll J. P.

School of Natural Resources: Faculty Publications

Abstract During 2004 and 2005, we monitored breeding season survival, home range, habitat use, density, and reproduction of northern bobwhite (Colinus virginianus) in the peninsular region of Florida, USA. We radio-tagged 81 birds across a 20-km2 cattle ranch consisting predominately of rotationally grazed pastureland. Birds were radio-tracked three to five times per week until mortality or the transition to nonbreeding season. We found no difference in home range size among the sexes, ages, or their interaction. Mean home range size pooled for years, sexes, and age class was 56.28 ha (±7.87 SE). Home ranges of bobwhites were not distributed among …

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 …

Pressures To Publish: Catalysts For The Loss Of Scientific Writing Integrity?, Cari-Ann Hayer, Mark A. Kaemingk, Jason J. Breeggemann, Daniel Dembkowski, David Deslauriers, Tobias Rapp

School of Natural Resources: Faculty Publications

Publishing research is the final step in the scientific process and is used as the primary means for disseminating research findings to the scientific community. Publishing can embody many personal motivations (e.g., gratification, seeing a finished product in print, desire to further science) for authors as well as professional benefits (e.g., promotion, tenure, future funding opportunities). As the scientific workforce and competition for jobs and funding increase, publishing productivity has become a driving factor for many authors, which may lead to writing practices that violate integrity. In this essay, we discuss writing actions that may be considered a violation of …

Field Guide For Nebraska Aquatic Invasive Species (Fg-26)

School of Natural Resources: Faculty Publications

No abstract provided.

Fostering Student Sense Making In Elementary Science Learning Environments: Elementary Teachers’ Use Of Science Curriculum Materials To Promote Explanation Construction, Laura Zangori, Cory Forbes, Mandy Biggers

School of Natural Resources: Faculty Publications

While research has shown that elementary (K-5) students are capable of engaging in the scientific practice of explanation construction, commonly-used elementary science curriculum materials may not always afford them opportunities to do so. As a result, elementary teachers must often adapt their science curriculum materials to better support students’ explanation construction and foster student sense making. However, little research has been conducted to explore if and, if so, how and why, elementary teachers modify science curriculum materials to engage students in explanation construction. We use an embedded mixed methods research design to explore elementary teachers’ (n = 45) curricular adaptations …

The Under-Ice Microbiome Of Seasonally Frozen Lakes, Stefan Bertilsson, Amy Burgin, Cayelan C. Carey, Samuel B. Fey, Hans-Peter Grossart, Lorena M. Grubisic, Ian D. Jones, Georgiy Kirillin, Jay T. Lennon, Ashley Shade, Robyn L. Smyth

School of Natural Resources: Faculty Publications

Compared to the well-studied open water of the ‘‘growing’’ season, under-ice conditions in lakes are characterized by low and rather constant temperature, slow water movements, limited light availability, and reduced exchange with the surrounding landscape. These conditions interact with ice-cover duration to shape microbial processes in temperate lakes and ultimately influence the phenology of community and ecosystem processes. We review the current knowledge on microorganisms in seasonally frozen lakes. Specifically, we highlight how under-ice conditions alter lake physics and the ways that this can affect the distribution and metabolism of auto- and heterotrophic microorganisms. We identify functional traits that we …

Students Understanding Of Cells And Heredity: Patterns Of Understanding In The Context Of A Curriculum Implementation In Fifth And Seventh Grades, Dante Cisterna, Michelle Williams, Joi Merritt

School of Natural Resources: Faculty Publications

No abstract provided.

Recent Updates Of The Calibration-Free Evapotranspiration Mapping (Cremap) Method, Jozsef Szilagyi

School of Natural Resources: Faculty Publications

No abstract provided.

Modeling The Production Of Multiple Ecosystem Services From Agricultural And Forest Landscapes In Rhode Island, Tingting Liu, Nathaniel H. Merrill, Arthur J. Gold, Dorothy Q. Kellogg, Emi Uchida

School of Natural Resources: Faculty Publications

No abstract provided.

High Spatial Resolution Mapping Of Elevated Atmospheric Carbon Dioxide Using Airborne Imaging Spectroscopy: Radiative Transfer Modeling And Power Plant Plume Detection, Philip E. Dennison, Andrew K. Thorpe, Eric R. Pardyjak, Dar A. Roberts, Yi Qi, Robert O. Green, Eliza S. Bradley, Christopher C. Funk

School of Natural Resources: Faculty Publications

No abstract provided.

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 …

Validation Of Noah-Simulated Soil Temperature In The North American Land Data Assimilation System Phase 2, Youlong Xia, Michael Ek, Justin Sheffield, Ben Livneh, Maoyi Huang, Helin Wei, Song Feng, Lifeng Luo, Jesse Meng, Eric Wood

School of Natural Resources: Faculty Publications

Soil temperature can exhibit considerable memory from weather and climate signals and is among the most important initial conditions in numerical weather and climate models. Consequently, a more accurate long term land surface soil temperature dataset is needed to improve weather and climate simulation and prediction, and is also important for the simulation of agricultural crop yield and ecological processes. The North American Land Data Assimilation phase 2 (NLDAS-2) has generated 31 years (1979–2009) of simulated hourly soil temperature data with a spatial resolution of 1/8°. This dataset has not been comprehensively evaluated to date. Thus, the purpose of this …

Nondetection Sampling Bias In Marked Presence-Only Data, Trevor Hefley, Andrew J. Tyre, David M. Baasch, Erin E. Blankenship

School of Natural Resources: Faculty Publications

1 Species distribution models (SDM) are tools used to determine environmental features that influence the geographic distribution of species’ abundance and have been used to analyze presence-only records. Analysis of presenceonly records may require correction for nondetection sampling bias to yield reliable conclusions. In addition, individuals of some species of animals may be highly aggregated and standard SDMs ignore environmental features that may influence aggregation behavior.

2 We contend that nondetection sampling bias can be treated as missing data. Statistical theory and corrective methods are well developed for missing data, but have been ignored in the literature on SDMs. We …

Correction Of Location Errors For Presence-Only Species Distribution Models, Trevor Hefley, David M. Baasch, Andrew J. Tyre, Erin E. Blankenship

School of Natural Resources: Faculty Publications

1. Species distribution models (SDMs) for presence-only data depend on accurate and precise measurements of geographical and environmental covariates that influence presence and abundance of the species. Some data sets, however, may contain both systematic and random errors in the recorded location of the species. Environmental covariates at the recorded location may differ from those at the true location and result in biased parameter estimates and predictions from SDMs.

2. Regression calibration is a well-developed statistical method that can be used to correct the bias in estimated coefficients and predictions from SDMs when the recorded geographical location differs from the …

Statistical Indicators And State–Space Population Models Predict Extinction In A Population Of Bobwhite Quail, Trevor Hefley, Andrew J. Tyre, Erin E. Blankenship

School of Natural Resources: Faculty Publications

Early warning systems of extinction thresholds have been developed for and tested in microcosm experiments, but have not been applied to populations of wild animals. We used state–space population models and a statistical indicator to detect a transcritical bifurcation extinction threshold in a population of bobwhite quail (Colinus virginianus) located in an agricultural region experiencing habitat deterioration and loss. The extinction threshold was detectible using two independent data sets. We compared predictions from state–space population models to predictions from a statistical indicator and found that predictions were corroborated. Using state–space population models, we estimated that our study population …

Miscanthus Establishment And Overwintering In The Midwest Usa: A Regional Modeling Study Of Crop Residue Management On Critical Minimum Soil Temperatures, Christopher J. Kucharik, Andy Vanloocke, John D. Lenters, Melissa M. Motew

School of Natural Resources: Faculty Publications

Miscanthus is an intriguing cellulosic bioenergy feedstock because its aboveground productivity is high for low amounts of agrochemical inputs, but soil temperatures below ‒3.5°C could threaten successful cultivation in temperate regions. We used a combination of observed soil temperatures and the Agro-IBIS model to investigate how strategic residue management could reduce the risk of rhizome threatening soil temperatures. This objective was addressed using a historical (1978–2007) reconstruction of extreme minimum 10 cm soil temperatures experienced across the Midwest US and model sensitivity studies that quantified the impact of crop residue on soil temperatures. At observation sites and for simulations that …

Assessing Migration Of Ruby-Throated Hummingbirds (Archilochus Colubris) At Broad Spatial And Temporal Scales Evaluación De La Migración De Archilochus Colubris A Escalas Amplias De Tiempo Y Espacio, Jason Courter, Ron J. Johnson, William C. Bridges Jr., Kenneth Hubbard

School of Natural Resources: Faculty Publications

Phenological patterns in birds appear to be temperature-dependent in part, and global temperatures are undergoing change. Many studies of bird phenology are conducted at broad temporal but local spatial scales, making it difficult to assess how temperature affects bird migration across landscapes. Recently, networks of “citizen science” volunteers have emerged whose collective efforts may improve phenology studies as biases associated with such efforts are recognized and addressed. We compared mean Rubythroated Hummingbird (Archilochus colubris) first arrival dates from Journey North (2001-2010) with data from the North American Bird Phenology Program (1880-1969). Ruby-throated Hummingbirds arrived earlier in the more recent period …

The Agricultural Model Intercomparison And Improvement Project (Agmip): Protocols And Pilot Studies, Cynthia Rosenzweig, J. W. Jones, J. L. Hatfield, Alex Ruane, K. J. Thornburn, J. M. Antle, G. C. Nelson, C. Porter, S. Janssen, B. Basso, F. Ewert, D. Wallach, G. Baigorria, J. M. Winter

School of Natural Resources: Faculty Publications

The Agricultural Model Intercomparison and Improvement Project (AgMIP) is a major international effort linking the climate, crop, and economic modeling communities with cutting-edge information technology to produce improved crop and economic models and the next generation of climate impact projections for the agricultural sector. The goals of AgMIP are to improve substantially the characterization of world food security due to climate change and to enhance adaptation capacity in both developing and developed countries. Analyses of the agricultural impacts of climate variability and change require a transdisciplinary effort to consistently link state-of-the-art climate scenarios to crop and economic models. Crop model …

The Agricultural Model Intercomparison And Improvement Project (Agmip): Protocols And Pilot Studies, Cynthia Rosenzweig, J. W. Jones, J. L. Hatfield, A. C. Ruane, K. J. Boote, P. Thornburn, J. M. Antle, G. C. Nelson, C. Porter, S. Janssen, S. Asseng, B. Basso, F. Ewert, D. Wallach, G. Baigorria, J. M. Winter

School of Natural Resources: Faculty Publications

The Agricultural Model Intercomparison and Improvement Project (AgMIP) is a major international effort linking the climate, crop, and economic modeling communities with cutting-edge information technology to produce improved crop and economic models and the next generation of climate impact projections for the agricultural sector. The goals of AgMIP are to improve substantially the characterization of world food security due to climate change and to enhance adaptation capacity in both developing and developed countries. Analyses of the agricultural impacts of climate variability and change require a transdisciplinary effort to consistently link state-of-the-art climate scenarios to crop and economic models. Crop model …

Spatial And Temporal Unpredictability Of Colony Size In Cliff Swallows Across 30 Years, Charles R. Brown, Mary Bomberger Brown, Erin A. Roche

School of Natural Resources: Faculty Publications

Most colonially breeding animals occupy colonies that range in size from a few pairs to thousands of individuals, but the causes of colony size variation are largely unknown. Three general hypotheses are: (1) that variation in colony size is maintained by fluctuating selection via spatial and temporal changes in fitness associated with different colony sizes; (2) that colony formation reflects heterogeneity in habitat, with some sites having resources to support more individuals than others; and (3) that individuals assess the presence or annual reproductive success of current colony residents at each site and aggregate preferentially at high-quality sites. These hypotheses …

The Relative Importance Of Exogenous And Substrate-Derived Nitrogen For Microbial Growth During Leaf Decomposition, B. M. Cheever, J. R. Webster, E. E. Bilger, S. A. Thomas

School of Natural Resources: Faculty Publications

Heterotrophic microbes colonizing detritus obtain nitrogen (N) for growth by assimilating N from their substrate or immobilizing exogenous inorganic N. Microbial use of these two pools has different implications for N cycling and organic matter decomposition in the face of the global increase in biologically available N. We used sugar maple leaves labeled with ¹⁵N to differentiate between microbial N that had been assimilated from the leaf substrate (enriched with ¹⁵N) or immobilized from the water (natural abundance ¹⁵N:¹⁴N) in five Appalachian streams ranging in ambient NO₃-N concentrations from about 5 to 900 …

2013 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 (2012–2013). 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 …

Surface Energy Balance Model Of Transpiration From Variable Canopy Cover And Evaporation From Residue-Covered Or Bare Soil Systems: Model Evaluation, Luis Octavio Lagos, Derrel Martin, Shashi B. Verma, Suat Irmak, Ayse Kilic, Dean E. Eisenhauer, Andrew E. Suyker

School of Natural Resources: Faculty Publications

A surface energy balance model (SEB) was extended by Lagos et al. Irrig Sci 28:51–64 (2009) to estimate evapotranspiration (ET) from variable canopy cover and evaporation from residue-covered or bare soil systems. The model estimates latent, sensible, and soil heat fluxes and provides a method to partition evapotranspiration into soil/residue evaporation and plant transpiration. The objective of this work was to perform a sensitivity analysis of model parameters and evaluate the performance of the proposed model to estimate ET during the growing and non-growing season of maize (Zea Mays L.) and soybeans (Glycine max) in eastern …

Influence Of Management And Precipitation On Carbon Fluxes In Great Plains Grasslands, Matthew Rigge, Bruce K. Wylie, Li Zhang, Stephen P. Boyte

United States Geological Survey: Staff Publications

Suitable management and sufficient precipitation on grasslands can provide carbon sinks. The net carbon accumulation of a site from the atmosphere, modeled as the Net Ecosystem Productivity (NEP), is a useful means to gauge carbon balance. Previous research has developed methods to integrate flux tower data with satellite biophysical datasets to estimate NEP across large regions. A related method uses the Ecosystem Performance Anomaly (EPA) as a satellite-derived indicator of disturbance intensity (e.g., livestock stocking rate, fire, and insect damage). To better understand the interactions among management, climate, and carbon dynamics, we evaluated the relationship between EPA and NEP data …