Other Environmental Sciences Commons^™

Monitoring Grassland Seasonal Carbon Dynamics, By Integrating Modis Ndvi, Proximal Optical Sampling, And Eddy Covariance Measurements, Enrica Nestola, Carlo Calfapietra, Craig A. Emmerton, Christopher Y. S. Wong, Donnette R. Thayer, John A. Gamon

School of Natural Resources: Faculty Publications

This study evaluated the seasonal productivity of a prairie grassland (Mattheis Ranch, in Alberta, Canada) using a combination of remote sensing, eddy covariance, and field sampling collected in 2012–2013. A primary objective was to evaluate different ways of parameterizing the light-use efficiency (LUE) model for assessing net ecosystem fluxes at two sites with contrasting productivity. Three variations on the NDVI (Normalized Difference Vegetation Index), differing by formula and footprint, were derived: (1) a narrow-band NDVI (NDVI680,800, derived from mobile field spectrometer readings); (2) a broad-band proxy NDVI (derived from an automated optical phenology station consisting of broad-band radiometers); and (3) …

Integrated Analysis Of Productivity And Biodiversity In A Southern Alberta Prairie, Ran Wang, John A. Gamon, Craig A. Emmerton, Haitao Li, Enrica Nestola, Gilberto Z. Pastorello, Olaf Menzer

School of Natural Resources: Faculty Publications

Grasslands play important roles in ecosystem production and support a large farming and grazing industry. An accurate and efficient way is needed to estimate grassland health and production for monitoring and adjusting management to get sustainable products and other ecosystem services. Previous studies of grasslands have shown varying relationships between productivity and biodiversity, with most showing either a positive or a hump-shaped relationship where productivity peaks at intermediate diversity. In this study, we used airborne imaging spectrometry combined with ground sampling and eddy covariance measurements to estimate the spatial pattern of production and biodiversity for two sites of contrasting productivity …

Interannual Variability In Dry Mixed-Grass Prairie Yield: A Comparison Of Modis, Spot, And Field Measurements, Donald C. Wehlage, John A. Gamon, Donnette Thayer, David V. Hildebrand

School of Natural Resources: Faculty Publications

Remote sensing is often used to assess rangeland condition and biophysical parameters across large areas. In particular, the relationship between the Normalized Difference Vegetation Index (NDVI) and above-ground biomass can be used to assess rangeland primary productivity (seasonal carbon gain or above-ground biomass “yield”). We evaluated the NDVI–yield relationship for a southern Alberta prairie rangeland, using seasonal trends in NDVI and biomass during the 2009 and 2010 growing seasons, two years with contrasting rainfall regimes. The study compared harvested biomass and NDVI from field spectrometry to NDVI from three satellite platforms: the Aqua and Terra Moderate Resolution Imaging Spectroradiometer (MODIS) …

Caught Between A Rock And A Hard Mineral Encrustation: Long-Lived Aquatic Insects Accumulate Calcium Carbonate Deposits In A Montane Desert Stream, Eric K. Moody, Jessica R. Corman, Michael T. Bogan

School of Natural Resources: Faculty Publications

Aquatic ecosystems overlying regions of limestone bedrock can feature active deposition of calcium carbonate in the form of travertine or tufa. Although most travertine deposits form a cement-like layer on stream substrates, mineral deposits can also form on benthic invertebrates. However, little is known about which taxa may be prone to calcium carbonate encrustation and which life history traits may make taxa more susceptible to becoming encrusted. Here we report the presence of calcium carbonate deposits on live insects collected from a montane stream in the Madrean Sky Islands (Huachuca Mountains) of Arizona between 2011 and 2013. Life history differences …

Avian Interactions With Renewable Energy Infrastructure: An Update, Jennifer A. Smith, James F. Dwyer

School of Natural Resources: Faculty Publications

Energy infrastructure is widespread worldwide. Renewable energy technologies, which are expanding their footprint on the landscape and their contribution to energy availability, represent a different kind of infrastructure from extractive energy technologies. Although renewable energy sources may offer a ‘greener alternative’ to traditional extractive energy sources, mounting evidence suggests that renewable energy infrastructure, and the transmission lines needed to convey energy from renewable energy facilities to users, may impact birds. Peer-reviewed literature historically has focused on the direct effects of electrocution and, to a lesser extent, collisions with overhead power systems, and on avian collisions at wind energy facilities, with …

Estimation Of Energy Balance Components Over A Drip-Irrigated Olive Orchard Using Thermal And Multispectral Cameras Placed On A Helicopter-Based Unmanned Aerial Vehicle (Uav), Samuel Ortega-Farias, Samuel Ortega-Salazar, Tomas Poblete, Ayse Kilic, Richard Allen, Carlos Poblete-Echeverria, Luis Ahumada-Orellana, Mauricio Zuniga, Daniel Sepulveda

School of Natural Resources: Faculty Publications

A field experiment was carried out to implement a remote sensing energy balance (RSEB) algorithm for estimating the incoming solar radiation (Rsi), net radiation (Rn), sensible heat flux (H), soil heat flux (G) and latent heat flux (LE) over a drip-irrigated olive (cv. Arbequina) orchard located in the Pencahue Valley, Maule Region, Chile (35^◦25'S; 71^◦44'W; 90 m above sea level). For this study, a helicopter-based unmanned aerial vehicle (UAV) was equipped with multispectral and infrared thermal cameras to obtain simultaneously the normalized difference vegetation index (NDVI) and surface temperature (Tsurface) at very high resolution (6 cm …

Acute 𝛽-N-Methylamino-L-Alanine Toxicity In A Mouse Model, Maitham Ahmed Al-Sammak, Douglas G. Rogers, Kyle D. Hoagland

School of Natural Resources: Faculty Publications

The cyanobacterial neurotoxin 𝛽-N-methylamino-L-alanine (BMAA) is considered to be an “excitotoxin,” and its suggested mechanism of action is killing neurons. Long-termexposure to L-BMAAis believed to lead to neurodegenerative diseases including Parkinson’s and Alzheimer’s diseases and amyotrophic lateral sclerosis (Lou Gehrig’s disease). Objectives of this study were to determine the presumptive median lethal dose (LD50), the Lowest-Observed-Adverse-Effect Level (LOAEL), and histopathologic lesions caused by the naturally occurring BMAA isomer, L-BMAA, in mice. Seventy NIH Swiss Outbred mice (35 male and 35 female) were used. Treatment group mice were injected intraperitoneally with 0.03, 0.3, 1, 2, and 3mg/g body weight L-BMAA, respectively, …

Advanced Space Vehicle Design Taking Into Account Multidisciplinary Couplings And Mixed Epistemic/Aleatory Uncertainties, Mathieu Balesdent, Loic Brevault, Nathaniel B. Price, Sebastien Defoort, Rodolphe Le Riche, Nam-Ho Kim, Raphael T. Haftka, Nicolas Berend

School of Natural Resources: Faculty Publications

No abstract provided.

Basic Forms And Orbit Spaces:A Diffeological Approach, Yael Karshon, Jordan Watts

School of Natural Resources: Faculty Publications

No abstract provided.

Seasonal Relationships Between Foliar Moisture Content, Heat Content And Biochemistry Of Lodgepole Pine And Big Sagebrush Foliage, Yi Qi, W. Matt Jolly, Philip E. Dennison, Rachael C. Kropp

School of Natural Resources: Faculty Publications

No abstract provided.

Rescaling Of The Complementary Relationship For Land Surface Evaporation, R. Crago, J. Szilagyi, R. Qualls, J. Huntington

School of Natural Resources: Faculty Publications

No abstract provided.

Metapopulation Viability Of An Endangered Shorebird Depends On Dispersal And Human-Created Habitats: Piping Plovers (Charadrius Melodus) And Prairie Rivers, Sara L. Zeigler, Daniel H. Catlin, Mary Bomberger Brown, Lauren R. Dinan, James D. Fraser, Kelsi L. Hunt, Joel G. Jorgensen

School of Natural Resources: Faculty Publications

Background: Many species are distributed as metapopulations in dynamic landscapes, where habitats change through space and time. Individuals locate habitat through dispersal, and the relationship between a species and landscape characteristics can have profound effects on population persistence. Despite the importance of connectivity in dynamic environments, few empirical studies have examined temporal variability in dispersal or its effect on metapopulation dynamics. In response to this knowledge gap, we studied the dispersal, demography, and viability of a metapopulation of an endangered, disturbance-dependent shorebird. We examined three subpopulations of piping plovers (Charadrius melodus) on the lower Platte and Missouri rivers …

Local Perspectives On Environmental Insecurity And Its Influence On Illegal Biodiversity Exploitation, Meredith L. Gore, Michelle L. Lute, Jonah H. Ratsimbazafy, Andry Rajaonson

School of Natural Resources: Faculty Publications

Environmental insecurity is a source and outcome of biodiversity declines and social conflict. One challenge to scaling insecurity reduction policies is that empirical evidence about local attitudes is overwhelmingly missing. We set three objectives: determine how local people rank risk associated with different sources of environmental insecurity; assess perceptions of environmental insecurity, biodiversity exploitation, myths of nature and risk management preferences; and explore relationships between perceptions and biodiversity exploitation. We conducted interviews (N = 88) with residents of Madagascar’s Torotorofotsy Protected Area, 2014. Risk perceptions had a moderate effect on perceptions of environmental insecurity. We found no effects of environmental …

Sustainable Grassland Management: An Exploratory Study Of Progressive Ranchers In Nebraska, Stephanie M. Kennedy, Mark E. Burbach, Maggi S. Sliwinski

School of Natural Resources: Faculty Publications

Well-managed grasslands provide numerous ecosystem services. Ranchers who employ sustainable grazing practices limit grassland conversion and conserve critical habitats. This phenomenological study explored the grassland management decisions of progressive ranchers in Nebraska. Each individual interviewed for this study is proactive about the state of their grasslands, whether they are motivated by financial or conservation factors. Throughout the evolution of their businesses, these ranchers have taken steps to improve their management techniques and continue to employ new strategies while planning for the long-term productivity of their grasslands. For policy makers and educators seeking to improve grassland management decisions, demonstrating new methods …

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 …

A Framework For Understanding The Characteristics Of Complexity In Biology, Joseph Dauer, Jenny Dauer

School of Natural Resources: Faculty Publications

Understanding the functioning of natural systems is not easy, although there is general agreement that understanding complex systems is an important goal for science education. Defining what makes a natural system complex will assist in identifying gaps in research on student reasoning about systems. The goal of this commentary is to propose a framework that explicitly defines the ways in which biological systems are complex and to discuss the potential relevance of these complexity dimensions to conducting research on student reasoning about complexity in biology classrooms. We use an engineering framework for dimensions of complexity and discuss how this framework …

Consequences Of Hatch Phenology On Stages Of Fish Recruitment, David M. Bogner, Mark A. Kaemingk, Melissa R. Wuellner

School of Natural Resources: Faculty Publications

Little is known about how hatch phenology (e.g., the start, peak, and duration of hatching) could influence subsequent recruitment of freshwater fishes into a population. We used two commonly sympatric fish species that exhibit different hatching phenologies to examine recruitment across multiple life stages. Nine yellow perch (Perca flavescens) and bluegill (Lepomis macrochirus) annual cohorts were sampled from 2004 through 2013 across larval, age-0, age-1, and age-2 life stages in a Nebraska (U.S.A.) Sandhill lake. Yellow perch hatched earlier in the season and displayed a more truncated hatch duration compared to bluegill. The timing of hatch …

Estimating Carbon Storage In Windbreak Trees On U.S. Agricultural Lands, W. B. Possu, James R. Brandle, G. M. Domke, M. Schoeneberger, Erin E. Blankenship

School of Natural Resources: Faculty Publications

Assessing carbon (C) capture and storage potential by the agroforestry practice of windbreaks has been limited. This is due, in part, to a lack of suitable data and associated models for estimating tree biomass and C for species growing under more opengrown conditions such as windbreaks in the Central Plains region of the United States (U.S.). We evaluated 15 allometric models using destructively sampled Pinus ponderosa (Lawson & C. Lawson) data from field windbreaks in Nebraska and Montana. Several goodness-of-fit metrics were used to select the optimal model. The Jenkins’ et al. model was then used to estimate biomass for …

Foraging Decisions Underlying Restricted Space Use: Effects Of Fire And Forage Maturation On Large Herbivore Nutrient Uptake, Edward J. Raynor, Anthony Joern, Jesse B. Nippert, John M. Briggs

School of Natural Resources: Faculty Publications

Recent models suggest that herbivores optimize nutrient intake by selecting patches of low to intermediate vegetation biomass. We assessed the application of this hypothesis to plains bison (Bison bison) in an experimental grassland managed with fire by estimating daily rates of nutrient intake in relation to grass biomass and by measuring patch selection in experimental watersheds in which grass biomass was manipulated by prescribed burning. Digestible crude protein content of grass declined linearly with increasing biomass, and the mean digestible protein content relative to grass biomass was greater in burned watersheds than watersheds not burned that spring (intercept; F_{1,251 …}

A Remotely Sensed Pigment Index Reveals Photosynthetic Phenology In Evergreen Conifers, John A. Gamon, K. Fred Huemmrich, Christopher Y.S. Wong, Ingo Ensminger, Steven Garrity, David Y. Hollinger, Asko Noormets, Josep Peñuelas

School of Natural Resources: Faculty Publications

In evergreen conifers, where the foliage amount changes little with season, accurate detection of the underlying “photosynthetic phenology” from satellite remote sensing has been difficult, presenting challenges for global models of ecosystem carbon uptake. Here, we report a close correspondence between seasonally changing foliar pigment levels, expressed as chlorophyll/carotenoid ratios, and evergreen photosynthetic activity, leading to a “chlorophyll/carotenoid index” (CCI) that tracks evergreen photosynthesis at multiple spatial scales. When calculated from NASA’s Moderate Resolution Imaging Spectroradiometer satellite sensor, the CCI closely follows the seasonal patterns of daily gross primary productivity of evergreen conifer stands measured by eddy covariance. This discovery …

Mesoscale Climatology And Variation Of Surface Winds Over The Chukchi–Beaufort Coastal Areas, Jing Zhang, Fuhong Liu, Wei Tao, Jeremy Krieger, Martha Shulski, Xiangdong Zhang

School of Natural Resources: Faculty Publications

The detailed mesoscale climatology of surface winds in the Chukchi–Beaufort Seas and adjacent Arctic Slope region is analyzed using the recently developed Chukchi–Beaufort High-Resolution Atmospheric Reanalysis (CBHAR). Within the study area, surface winds are mainly driven by the prevailing synoptic weather patterns of the Beaufort high and Aleutian low and are further modulated by local geographic features through thermodynamic and dynamic processes. Sea breezes, up- or downslope winds, and the mountain barrier jets are all clearly captured by CBHAR. Sea breezes emerge in June–September and last most of the day, with a maximum spatial extent 100km inland and 50 km …

Winter Diet And Hunting Success Of Canada Lynx In Colorado, Jacob S. Ivan, Tanya M. Shenk

School of Natural Resources: Faculty Publications

Information regarding the diet of Canada lynx (Lynx canadensis) at the southernmost extent of its range is critical for managing the species under current and predicted climate conditions. Therefore, from 1999–2009, we investigated winter diet and hunting strategies of Canada lynx in Colorado, USA by tracking individuals in the snow to identify sites where lynx encountered and killed prey. Similar to other parts of lynx range, snowshoe hares (Lepus americanus) were the primary winter food in Colorado, especially when considering total biomass consumed. Red squirrels (Tamiasciurus hudsonicus) comprised the bulk of the remaining food …

The Sensitivity Of Carbon Exchanges In Great Plains Grasslands To Precipitation Variability, M. D. Petrie, N. A. Brunsell, R. Vargas, S. L. Collins, L. B. Flanagan, N. P. Hanan, M. E. Litvak, Andrew E. Suyker

School of Natural Resources: Faculty Publications

In the Great Plains, grassland carbon dynamics differ across broad gradients of precipitation and temperature, yet finer-scale variation in these variables may also affect grassland processes. Despite the importance of grasslands, there is little information on how fine-scale relationships compare between them regionally. We compared grassland C exchanges, energy partitioning and precipitation variability in eight sites in the eastern and western Great Plains using eddy covariance and meteorological data. During our study, both eastern and western grasslands varied between an average net carbon sink and a net source. Eastern grasslands had a moderate vapor pressure deficit (VPD = 0.95 kPa) …

Status Of Knowledge Of The Shovelnose Sturgeon (Scaphirhynchus Platorynchus, Rafinesque, 1820), Q. E. Phelps, S. J. Tripp, M. J. Hamel, J. Koch, E. J. Heist, J. E. Garvey, K. M. Kappenman, M. A. H. Webb

School of Natural Resources: Faculty Publications

The range of Shovelnose Sturgeon (SVS) Scaphirhynchus platorynchus in the great rivers of central North America has contracted, but most remaining populations are considered stable, likely due to a combination of successful harvest regulations and longitudinal continuity of many river reaches, despite damming in upper reaches. The evolutionary relationships of SVS relative to sister taxa is still a matter of debate. Genetic diversity varies across the range, with substantial haplotype overlap among SVS and its congeners. Shovelnose Sturgeon mature early at 5–7 years, and spawn every 2– 3 years. Some individuals may spawn in fall. Whether this species migrates is …

Spatiotemporal Patterns Of Water Table Fluctuations And Evapotranspiration Induced By Riparian Vegetation In A Semiarid Area, Weifeng Yue, Tiejun Wang, Trenton E. Franz, Xunhong Chen

School of Natural Resources: Faculty Publications

Groundwater evapotranspiration (ET_g) links various ecohydrological processes and is an important component in regional water budgets. In this study, an extensive monitoring network was established in a semiarid riparian area to investigate various controls on the spatiotemporal pattern of water table fluctuations (WTFs) and ET_g induced by riparian vegetation. Along a vegetation gradient (~1200 m), diurnal WTFs were observed during a growing season in areas covered by woody species (Populus sect. Aigeiros and Juniperus virginiana) and wet slough vegetation (Panicum virgatum and Bromus inermis) with deeper root systems; whereas, no diurnal WTFs were …

Developing Coherent Conceptual Storylines: Two Elementary Challenges, Deborah Hanuscin, Kelsey Lipsitz, Dante Cisterna-Alburquerque, Kathryn A. Arnone, Delinda Van Garderen, Zandra De Araujo, Eun Ju Lee

School of Natural Resources: Faculty Publications

No abstract provided.

2016 Interior Least Tern And Piping Plover Monitoring, Research, Management, And Outreach Report For The Lower Platte River, Nebraska, Mary Bomberger Brown, 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 (2015 – 2016). 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 data, data analyses, results, summaries, and interpretations found in this document are not final and should be considered as such when being cited or referred to in documents, reports, proposals, or presentations. Please contact us before using any of this material and for additional information that may be available.

In an effort to …

Agroforestry Horizons: Experiences And Reflections: Report-Out, Steve Rasmussen

United States Department of Agriculture, Forest Service / University of Nebraska-Lincoln: Faculty Publications

The USDA National Agroforestry Center (NAC) is charting a course for the next five years. As part of this process, NAC and the USDA Interagency Agroforestry Team hosted a meeting of leaders in the fields of agroforestry, agriculture, and forestry, from government, universities, and the private sector, to share experiences and insights on agroforestry opportunities and challenges. The meeting occurred on April 27th and 28th, 2016, in Washington, DC, and entailed presentations and discussions on current and potential roles of agroforestry in supporting water quality, soil health, economic diversification, food security, and pollinator/wildlife habitat. This report-out provides a summary of …

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 …