Physical Sciences and Mathematics Commons^™

Revision Of Nationwide Design Flood Levels (In Hungarian), T. Kramer, Jozsef Szilagyi, J. Jozsa

School of Natural Resources: Faculty Publications

No abstract provided.

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 …

The Need For A Common Basis For Defining Light-Use Efficiency: Implications For Productivity Estimation, Anatoly A. Gitelson, John A. Gamon

School of Natural Resources: Faculty Publications

A primary focus of this short communication is to show how the operational definition of light use efficiency (LUE) influences the results and interpretation of the LUE model. Our study was motivated by the observation that multiple LUE definitions are reported in the literature. The temporal behavior of three operational definitions of LUE, based on (i) incident radiation, (ii) total absorbed radiation and (iii) radiation absorbed by photosynthetically active/green vegetation was examined for two contrasting crops (soybean and maize) having different physiologies, leaf structures and canopy architectures. Over the course of a growing season, the behavior of these three contrasting …

Joint Leaf Chlorophyll Content And Leaf Area Index Retrieval From Landsat Data Using A Regularized Model Inversion System (Regflec), Rasmus Houborg, Matthew Mccabe, Alessandro Cescatti, Feng Gao, Mitchell Schull, Anatoly A. Gitelson

School of Natural Resources: Faculty Publications

Leaf area index (LAI) and leaf chlorophyll content (Chll) represent key biophysical and biochemical controls on water, energy and carbon exchange processes in the terrestrial biosphere. In combination, LAI and Chll provide critical information on vegetation density, vitality and photosynthetic potentials.However, simultaneous retrieval of LAI and Chll fromspace observations is extremely challenging. Regularization strategies are required to increase the robustness and accuracy of retrieved properties and enable more reliable separation of soil, leaf and canopy parameters. To address these challenges, the REGularized canopy reFLECtance model (REGFLEC) inversion system was refined to incorporate enhanced techniques for exploiting ancillary LAI and temporal …

Soil Processes Drive Seasonal Variation In Retention Of 15N Tracers In A Deciduous Forest Catchment, Christine L. Goodale, Guinevere Fredriksen, Marissa S. Weiss, Carmody K. Mccalley, Jed P. Sparks, Steven A. Thomas

School of Natural Resources: Faculty Publications

Seasonal patterns of stream nitrate concentration have long been interpreted as

demonstrating the central role of plant uptake in regulating stream nitrogen loss from forested

catchments. Soil processes are rarely considered as important drivers of these patterns. We

examined seasonal variation in N retention in a deciduous forest using three whole-ecosystem

¹⁵N tracer additions: in late April (post-snowmelt, pre-leaf-out), late July (mid-growingseason),

and late October (end of leaf-fall). We expected that plant ¹⁵N uptake would peak in

late spring and midsummer, that immobilization in surface litter and soil would peak the

following autumn leaf-fall, and that leaching losses …

A Global Perspective On Wetland Salinization: Ecological Consequences Of A Growing Threat To Freshwater Wetlands, Ellen R. Herbert, Paul Boon, Amy J. Burgin, Scott C. Neubauer, Rima B. Franklin, Marcelo Ardón, Kristine N. Hopfensperger, Leon P.M. Lamers, Peter Gell

School of Natural Resources: Faculty Publications

Salinization, a widespread threat to the structure and ecological functioning of inland and coastal wetlands, is currently occurring at an unprecedented rate and geographic scale. The causes of salinization are diverse and include alterations to freshwater flows, land-clearance, irrigation, disposal of wastewater effluent, sea level rise, storm surges, and applications of de-icing salts. Climate change and anthropogenic modifications to the hydrologic cycle are expected to further increase the extent and severity of wetland salinization. Salinization alters the fundamental physicochemical nature of the soil-water environment, increasing ionic concentrations and altering chemical equilibria and mineral solubility. Increased concentrations of solutes, especially sulfate, …

Factors Affecting Female Space Use In Ten Populations Of Prairie Chickens, Virginia L. Winder, Kaylan M. Carrlson, Andrew J. Gregory, Christian A. Hagen, David A. Haukos, Dylan C. Kesler, Lena C. Larsson, Ty W. Matthews, Lance B. Mcnew, Michael A. Patten, Jim C. Pitman, Larkin A. Powell, Jennifer A. Smith, Tom Thompson, Donald H. Wolfe, Brett K. Sandercock

School of Natural Resources: Faculty Publications

Conservation of wildlife depends on an understanding of the interactions between animal

movements and key landscape factors. Habitat requirements of wide-ranging species often vary spatially,

but quantitative assessment of variation among replicated studies at multiple sites is rare. We investigated

patterns of space use for 10 populations of two closely related species of prairie grouse: Greater Prairie-

Chickens (Tympanuchus cupido) and Lesser Prairie-Chickens (T. pallidicinctus). Prairie chickens require large,

intact tracts of native grasslands, and are umbrella species for conservation of prairie ecosystems in North

America. We used resource utilization functions to investigate space use by female prairie chickens during …

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 …

Biotic And Climatic Controls On Interannual Variability In Carbon Fluxes Across Terrestrial Ecosystems, Junjiong Shao, Xuhui Zhou, Yiqi Luo, Bo Li, Mika Aurela, David Billesbach, Peter D. Blanken, Rosvel Bracho, Jiquan Chen, Marc L. Fischer, Yuling Fu, Lianhong Gu, Shijie Han, Yongtao He, Thomas Kolb, Yingnian Li, Zoltan Nagy, Shuli Niu, Walter C. Oechel, Krisztina Pinter, Peili Shi, Andrew E. Suyker, Margaret Torn, Andrej Varlagin, Huimin Wang, Junhua Yan, Guirui Yu, Junhui Zhang

School of Natural Resources: Faculty Publications

Interannual variability (IAV, represented by standard deviation) in net ecosystem exchange of CO₂ (NEE) is mainly driven by climatic drivers and biotic variations (i.e., the changes in photosynthetic and respiratory responses to climate), the effects of which are referred to as climatic (CE) and biotic effects (BE), respectively. Evaluating the relative contributions of CE and BE to the IAV in carbon (C) fluxes and understanding their controlling mechanisms are critical in projecting ecosystem changes in the future climate. In this study, we applied statistical methods with flux data from 65 sites located in the Northern Hemisphere to address this …

Estimation And Analysis Of Gross Primary Production Of Soybean Under Various Management Practices And Drought Conditions, Pradeep Wagle, Xiangming Xiao, Andrew E. Suyker

School of Natural Resources: Faculty Publications

Gross primary production (GPP) of croplands may be used to quantify crop productivity and evaluate a range of management practices. Eddy flux data from three soybean (Glycine max L.) fields under different management practices (no-till vs. till; rainfed vs. irrigated) and Moderate Resolution Imaging Spectroradiometer (MODIS) derived vegetation indices (VIs) were used to test the capabilities of remotely sensed VIs and soybean phenology to estimate the seasonal dynamics of carbon fluxes. The modeled GPP (GPP_VPM) using vegetation photosynthesis model (VPM) was compared with the GPP (GPP_EC) estimated from eddy covariance measurements. The VIs tracked soybean …

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 …

Are Preserved Farms Actively Engaged In Agriculture And Conservation?, Paul D. Gottlieb, Brian J. Schilling, Kevin Sullivan, J. Dixon Esseks, Lori Lynch, Joshua M. Duke

School of Natural Resources: Faculty Publications

This study addresses the question of whether farms enrolled in land preservation programs are actively engaged in agricultural or conservation activities. Data are drawn from an original survey administered to preserved farm owners in the states of New Jersey, Maryland, and Delaware in 2011. “Actively engaged” is defined as investment in conservation projects, buildings, equipment, or irrigation since the land was preserved. Affirmative answers to the survey’s investment questions range from a low of 19% for irrigation to a high of 69% for equipment. Special attention was paid to differences between lifestyle farmers and small and large commercial farmers, which …

The Accumulated Winter Season Severity Index (Awssi), Barbara E. Mayes Boustead, Steven D. Hilberg, Martha Shulski, Kenneth Hubbard

School of Natural Resources: Faculty Publications

The character of a winter can be defined by many of its features, including temperature averages and extremes, snowfall totals, snow depth, and the duration between onset and cessation of winter-weather conditions. The accumulated winter season severity index incorporates these elements into one site-specific value that defines the severity of a particular winter, especially when examined in the context of climatological values for that site. Thresholds of temperature, snowfall, and snow depth are assigned points that accumulate through the defined winter season; a parallel index uses temperature and precipitation to provide a snow proxy where snow data are unavailable or …

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 …

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.

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.

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.

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.