Other Environmental Sciences Commons^™

The Uncertain Climate Footprint Of Wetlands Under Human Pressure, Ana Maria Roxana Petrescu, Annalea Lohila, Juha-Pekka Tuovinen, Dennis D. Baldocchi, Ankur R. Desai, Nigel T. Roulet, Timo Vesala, Albertus Johannes Dolman, Walter C. Oechel, Barbara Marcolla, Thomas Friborg, Janne Rinne, Jaclyn Hatala Matthes, Lutz Merbold, Ana Meijide, Gerard Kiely, Matteo Sottocornola, Torsten Sachs, Donatella Zona, Andrej Varlagin, Derrick Y.F. Lai, Elmar Veenendaal, Frans-Jan W. Parmentier, Ute Skiba, Magnus Land, Arjan Hensen, Jacobus Van Huissteden, Lawrence B. Flanagan, Narasinha J. Shurpali, Thomas Grünwald, Elyn R. Humphreys, Marcin Jackowicz-Korczynski, Mika A. Aurela, Tuomas Laurila, Carsten Grüning, Chiara A.R. Corradi, Arina P. Schrier-Uijl, Torben R. Christensen, Mikkel P. Tamstorf, Mikhail Mastepanov, Pertti J. Martikainen, Shashi Verma, Christian Bernhofer, Alessandro Cescatti

School of Natural Resources: Faculty Publications

Significant climate risks are associated with a positive carbon–temperature feedback in northern latitude carbon-rich ecosystems,making an accurate analysis of human impacts on the net greenhouse gas balance of wetlands a priority. Here, we provide a coherent assessment of the climate footprint of a network of wetland sites based on simultaneous and quasi-continuous ecosystem observations of CO₂ and CH₄ fluxes. Experimental areas are located both in natural and in managed wetlands and cover a wide range of climatic regions, ecosystem types, and management practices. Based on direct observations we predict that sustained CH₄ emissions in natural ecosystems are …

Thermal-Based Modeling Of Coupled Carbon, Water, And Energy Fluxes Using Nominal Light Use Efficiencies Constrained By Leaf Chlorophyll Observations, M. A. Schull, M. C. Anderson, R. Houborg, Anatoly A. Gitelson, W. P. Kustas

School of Natural Resources: Faculty Publications

Recent studies have shown that estimates of leaf chlorophyll content (Chl), defined as the combined mass of chlorophyll a and chlorophyll b per unit leaf area, can be useful for constraining estimates of canopy light use efficiency (LUE). Canopy LUE describes the amount of carbon assimilated by a vegetative canopy for a given amount of absorbed photosynthetically active radiation (APAR) and is a key parameter for modeling land-surface carbon fluxes. A carbonenabled version of the remote-sensing-based two-source energy balance (TSEB) model simulates coupled canopy transpiration and carbon assimilation using an analytical submodel of canopy resistance constrained by inputs of nominal …

Phycocyanin-Specific Absorption Coefficient: Eliminating The Effect Of Chlorophylls Absorption, Y. Z. Yacobi, J. Köhler, F. Leunert, Anatoly A. Gitelson

School of Natural Resources: Faculty Publications

The applicability of algorithms for estimation of phycocyanin (PC) concentration based on light spectral reflectance heavily depends on the specific absorption of the pigment. But the determination of PC-specific absorption coefficient is not a straightforward task, as PC optical activity is overlapped by absorption of chlorophylls. The aim of our study was to determine a*_PC(625)—the specific absorption coefficient of PC at 625 nm, in samples with PC concentrations ranging from 0.5 mg m^-3 to 126.4 mg m^-3 and varying proportions of chlorophylls a, b, and c in the samples. The effect of chlorophylls was subtracted from …

Modeling Actual Evapotranspiration With Routine Meteorological Variables In The Data-Scarce Region Of The Tibetan Plateau: Comparisons And Implications, Ning Ma, Yinsheng Zhang, Chong-Yu Xu, Jozsef Szilagyi

School of Natural Resources: Faculty Publications

Quantitative estimation of actual evapotranspiration (ET_a) by in situ measurements and mathematical modeling is a fundamental task for physical understanding of ETa as well as the feedback mechanisms between land and the ambient atmosphere. However, the ETa information in the Tibetan Plateau (TP) has been greatly impeded by the extremely sparse ground observation network in the region. Approaches for estimating ET_a solely from routine meteorological variables are therefore important for investigating spatiotemporal variations of ETa in the data-scarce region of the TP. Motivated by this need, the complementary relationship (CR) and Penman-Monteith approaches were evaluated against in …

Remote Sensing Of Drought: Progress, Challenges And Opportunities, A. Aghakouchak, A. Farahmand, F. S. Melton, J. Teixeira, M. C. Anderson, Brian D. Wardlow, C. R. Hain

School of Natural Resources: Faculty Publications

This review surveys current and emerging drought monitoring approaches using satellite remote sensing observations from climatological and ecosystem perspectives. We argue that satellite observations not currently used for operational drought monitoring, such as near-surface air relative humidity data from the Atmospheric Infrared Sounder mission, provide opportunities to improve early drought warning. Current and future satellite missions offer opportunities to develop composite and multi-indicator drought models. While there are immense opportunities, there are major challenges including data continuity, unquantified uncertainty, sensor changes, and community acceptability. One of the major limitations of many of the currently available satellite observations is their short …

Evaluating The Complementary Relationship Of Evapotranspiration In The Alpine Steppe Of The Tibetan Plateau, Ning Ma, Yinsheng Zhang, Jozsef Szilagyi, Yanhong Guo, Jianqing Zhai, Haifeng Gao

School of Natural Resources: Faculty Publications

The complementary relationship (CR) of evapotranspiration allows the estimation of the actual evapotranspiration rate (ET_a) of the land surface using only routine meteorological data, which is of great importance in the Tibetan Plateau (TP) due to its sparse observation network. With the highest in situ automatic climate observation system in a typical semiarid alpine steppe region of the TP, the wind function of Penman was replaced by one based on the Monin-Obukhov Similarity theory for calculating the potential evapotranspiration rate (ET_p); the Priestley-Taylor coefficient, a, was estimated using observations in wet days; and the slope of …

Complementary-Relationship-Based 30 Year Normals (1981–2010) Of Monthly Latent Heat Fluxes Across The Contiguous United States, Jozsef Szilagyi

School of Natural Resources: Faculty Publications

Thirty year normal (1981–2010) monthly latent heat fluxes (ET) over the conterminous United States were estimated by a modified Advection-Aridity model from North American Regional Reanalysis (NARR) radiation and wind as well as Parameter-Elevation Regressions on Independent Slopes Model (PRISM) air and dew-point temperature data. Mean annual ET values were calibrated with PRISM precipitation (P) and validated against United States Geological Survey runoff (Q) data. At the six-digit Hydrologic Unit Code level (sample size of 334) the estimated 30 year normal runoff (P – ET) had a bias of 18 mm yr^-1, a root-mean-square error of …

Atmospheric Circulation Processes Contributing To A Multidecadal Variation In Reconstructed And Modeled Indian Monsoon Precipitation, Qianru Wu, Qi Hu

School of Natural Resources: Faculty Publications

An analysis of the recently reconstructed gridded May–September total precipitation in the Indian monsoon region for the past half millennium discloses significant variations at multidecadal timescales. Meanwhile, paleo-climate modeling outputs from the National Center for Atmospheric Research Community Climate System Model 4.0 show similar multidecadal variations in the monsoon precipitation. One of those variations at the frequency of 40–50 years per cycle is examined in this study. Major results show that this variation is a product of the processes in that the meridional gradient of the atmospheric enthalpy is strengthened by radiation loss in the high-latitude and polar region. Driven …

Combined Analysis Of Soil Moisture Measurements From Roving And Fixed Cosmic Ray Neutron Probes For Multiscale Real-Time Monitoring, Trenton E. Franz, Tiejun Wang, William Avery, Catherine E. Finkenbiner, Luca Brocca

School of Natural Resources: Faculty Publications

Soil moisture partly controls land-atmosphere mass and energy exchanges and ecohydrological processes in natural and agricultural systems. Thus, many models and remote sensing products continue to improve their spatiotemporal resolution of soil moisture, with some land surface models reaching 1 km resolution. However, the reliability and accuracy of both modeled and remotely sensed soil moisture require comparison with ground measurements at the appropriate spatiotemporal scales. One promising technique is the cosmic ray neutron probe. Here we further assess the suitability of this technique for real-time monitoring across a large area by combining data from three fixed probes and roving surveys …

Bringing The Passion Back: Using Your Expertise To Gain Experience, Improve Motivation, And Create Real Change In Global Agriculture, J.M.D. Motschenbacher

School of Natural Resources: Faculty Publications

No abstract provided.

Daily Soil Surface Co2 Flux During Non-Flooded Periods In Flood-Irrigated Rice Rotations, J. M. Motschenbacher, K. R. Brye, M. M. Anders, E. E. Gbur, N. A. Slaton, M. A. Evans-White

School of Natural Resources: Faculty Publications

No abstract provided.

Atmospheric Responses To North Atlantic Sst Anomalies In Idealized Experiments. Part I: Northern Hemispheric Circulation, Michael C. Veres, Qi Hu

School of Natural Resources: Faculty Publications

Idealized model experiments using the NCAR CESM1.0.5 under equinox conditions are designed and performed to address two fundamental questions about the effects of the sea surface temperature (SST) variation associated with the Atlantic multidecadal oscillation (AMO) on circulation and precipitation in North America and Europe: 1) Is the observed relationship between the AMOSST and the warm-season precipitation in North America a statistical coincidence? and 2)Why is the response of negative precipitation anomaly to warm SST in the AMO fairly uniform across most of North America, whereas the positive precipitation anomaly in the cold SST rather spotty? Model experiments are done …

Estimation Of Crop Gross Primary Production (Gpp): Ii. Do Scaledmodis Vegetation Indices Improve Performance?, Qingyuan Zhang, Yen-Ben Cheng, Alexei I. Lyapustin, Yujie Wang, Xiaoyang Zhang, Andrew E. Suyker, Shashi Verma, Yanmin Shuai, Elizabeth M. Middleton

School of Natural Resources: Faculty Publications

Satellite remote sensing estimates of gross primary production (GPP) have routinely been made using spectral vegetation indices (VIs) over the past two decades. The Normalized Difference Vegetation Index(NDVI), the Enhanced Vegetation Index (EVI), the green band Wide Dynamic Range Vegetation Index(WDRVI_green), and the green band Chlorophyll Index (CI_green) have been employed to estimate GPP under the assumption that GPP is proportional to the product of VI and photosynthetically active radiation (PAR)(where VI is one of four VIs: NDVI, EVI, WDRVI_green, or CI_green). However, the empirical regressions between VI*PAR and GPP measured locally …

An Exploration Of The Moderating Effect Of Motivation On The Relationship Between Work Satisfaction And Utilization Of Virtual Team Effectiveness Attributes: A Mixed Methods Study, F. C. Day, Mark E. Burbach

School of Natural Resources: Faculty Publications

No abstract provided.

A Unifying Gravity Framework For Dispersal, E. Jongejans, O. Skarpaas, M. J. Ferrari Et Al.

School of Natural Resources: Faculty Publications

No abstract provided.

Evaluating An Unconfined Aquifer By Analysis Of Age-Dating Tracers In Stream Water, D. K. Solomon, T. E. Gilmore, B. Kimball, D. P. Genereux

School of Natural Resources: Faculty Publications

The mean transit time (MTT) is a fundamental property of a groundwater flow system that is strongly related to the ratio of recharge rate to storage volume. However, obtaining samples for estimating the MTT using environmental tracers is problematic as flow-weighted samples over the full spectrum of transit times are needed. Samples collected fromthe base flow of a gaining stream in the North Carolina Coastal Plain (West Bear Creek) that were corrected for exchange with the atmosphere yielded environmental tracer concentrations (SF₆ and CFC-11) very similar to flow-weighted values from nine or ten streambed piezometers that directly sampled groundwater …

Application Of Remote Sensing For Quantifying And Mapping Surface Energy Fluxes In South Central Nebraska: Analyses With Respect To Field Measurements, Vivek Sharma, Suat Irmak, Ayse Kilic, Denis Mutibwa

School of Natural Resources: Faculty Publications

Large-scale quantification of crop evapotranspiration (ETc) from various vegetation surfaces can aid in planning, managing, and allocating water resources. Field measurement of surface energy fluxes, including ETc, remains (and should remain) a crucial process for calibration and validation of satellite/remote sensing-based methods, which can provide important supporting information for water balance assessments and for analyzing the spatial distribution of energy fluxes on large scales. The Surface Energy Balance System (SEBS) was evaluated in estimating surface energy fluxes in south central Nebraska using Landsat imagery and meteorological data. SEBS-estimated surface energy fluxes were compared to Bowen Ratio Energy Balance System (BREBS) …

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

School of Natural Resources: Faculty Publications

Abstract:

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

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

A Mixed-Methods Approach To Assessing Success In Transitioning Water Management Institutions: A Case Study Of The Platte River Basin, Nebraska, Christina Hoffman Babbitt, Mark E. Burbach, Lisa Pennisi

School of Natural Resources: Faculty Publications

To address increasing conflicts between surface water and groundwater users, the state of Nebraska has adopted a more localized and integrated approach in managing water resources. Integrated approaches offer promise in better managing connected water resources within the state; however, little review of the potential benefits and/or challenges of these actions has been conducted. This case study uses both qualitative and quantitative data collection efforts to take an in-depth look at how this new and innovative management system is working through the eyes of stakeholders living and working in the basin. Data collection reveals that overall the current water management …

Twentieth Century Droughts And Agriculture: Examples From Impacts On Soybean Production In Kentucky, Usa, Rezaul Mahmood

School of Natural Resources: Faculty Publications

No abstract provided.

Investigating Diurnal And Seasonal Climatic Response To Land Use And Land Cover Change Over Monsoon Asia With The Community Earth System Model, Rezaul Mahmood

School of Natural Resources: Faculty Publications

No abstract provided.

Land Use/Land Cover Changes And Regional Climate Over The Loess Plateau During 2001-2009 – Part I. Observed Evidences, Rezaul Mahmood

School of Natural Resources: Faculty Publications

No abstract provided.

Land Use/Land Cover Changes And Regional Climate Over The Loess Plateau During 2001-2009 – Part Ii., Rezaul Mahmood

School of Natural Resources: Faculty Publications

No abstract provided.

Neural Network Analysis On The Effect Of Heat Fluxes On Greenhouse Gas Emissions From Anaerobic Swine Waste Treatment Lagoon, N. Lovanh, J. Loughrin, M. Rysz, A. I. Quintanar, B. T. Oh, Rezaul Mahmood

School of Natural Resources: Faculty Publications

No abstract provided.

Enso Teleconnection Pattern Changes Over The Southeastern United States Under A Climate Change Scenario In Cmip5 Models, Ji-Hyun Oh, D.W. Shin, Steven D. Cocke, Guillermo A. Baigorria

School of Natural Resources: Faculty Publications

A strong teleconnection exists between the sea surface temperature (SST) over the tropical Pacific and the winter precipitation in the southeastern United States (SE US).This feature is adopted to validate the fidelity of Coupled Model Intercomparison Project Phase 5 (CMIP5) in this study. In addition, the authors examine whether the teleconnection pattern persists in the future under a global warming scenario. Generally, most of the eight selected models show a positive correlation between November SST over Ni˜no 3 region and December–February (DJF) mean daily precipitation anomalies over the SE US, consistent with the observation. However, the models with poor realization …

Modeling The Snow Surface Temperature With A One-Layer Energy Balance Snowmelt Model, J. You, D. G. Tarboton, C. H. Luce

School of Natural Resources: Faculty Publications

Snow surface temperature is a key control on and result of dynamically coupled energy exchanges at the snow surface. The snow surface temperature is the result of the balance between external forcing (incoming radiation) and energy exchanges above the surface that depend on surface temperature (outgoing longwave radiation and turbulent fluxes) and the transport of energy into the snow by conduction and meltwater influx. Because of the strong insulating properties of snow, thermal gradients in snow packs are large and nonlinear, a fact that has led many to advocate multiple layer snowmelt models over single layer models. In an effort …

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

School of Natural Resources: Faculty Publications

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

Translating Aboveground Cosmic-Ray Neutron Intensity To High-Frequency Soil Moisture Profiles At Sub-Kilometer Scale, R. Rosolem, T. Hoar, A. Arellano, J. L. Anderson, W. J. Shuttleworth, X. Zeng, Trenton E. Franz

School of Natural Resources: Faculty Publications

Above-ground cosmic-ray neutron measurements provide an opportunity to infer soil moisture at the subkilometer scale. Initial efforts to assimilate those measurements have shown promise. This study expands such analysis by investigating (1) how the information from aboveground cosmic-ray neutrons can constrain the soil moisture at distinct depths simulated by a land surface model, and (2) how changes in data availability (in terms of retrieval frequency) impact the dynamics of simulated soil moisture profiles. We employ ensemble data assimilation techniques in a “nearly-identical twin” experiment applied at semi-arid shrubland, rainfed agricultural field, and mixed forest biomes in the USA. The performance …

Connections Between Student Explanations And Arguments From Evidence About Plant Growth, Jenny Dauer, Jennifer H. Doherty, Allison L. Freed, Charles W. Anderson

School of Natural Resources: Faculty Publications

We investigate how students connect explanations and arguments from evidence about plant growth and metabolism—two key practices described by the Next Generation Science Standards. This study reports analyses of interviews with 22 middle and high school students postinstruction, focusing on how their sense-making strategies led them to interpret—or misinterpret—scientific explanations and arguments from evidence. The principles of conservation of matter and energy can provide a framework for making sense of phenomena, but our results show that some students reasoned about plant growth as an action enabled by water, air, sunlight, and soil rather than a process of matter and energy …

Macroinvertebrate Prey Availability And Food Web Dynamics Of Nonnative Trout In A Colorado River Tributary, Grand Canyon, Daniel P. Whiting, Craig P. Paukert, Brian D. Healy, Jonathan Spurgeon

School of Natural Resources: Faculty Publications

Nonnative fishes have been linked to the decline of native fishes and may affect aquatic food webs through direct and indirect pathways. These concerns have led to efforts to remove nonnative Brown and Rainbow Trout, which are abundant in tributaries of the Colorado River, to enhance native fish communities. We sampled fish, benthic, and drifting macroinvertebrates in November 2010, January 2011, June 2011, and September 2011 to assess resource availability and to evaluate the effects of nonnative Brown and Rainbow Trout in a tributary of the Colorado River in the Grand Canyon. We evaluated trout diets from stomach samples collected …