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Full-Text Articles in Physical Sciences and Mathematics

Enhancing Urban Water Quality Through Biological-Chemical Treatment: Aquatic Macroinvertebrate Community And Temporal Chlorophyll-A Response, Matthew Chaffee Dec 2023

Enhancing Urban Water Quality Through Biological-Chemical Treatment: Aquatic Macroinvertebrate Community And Temporal Chlorophyll-A Response, Matthew Chaffee

Department of Agricultural and Biological Systems Engineering: Dissertations, Theses, and Student Research

With a growing human population, urbanization is impeding a plethora of natural waterways. Of these, urban ponds play a vital role in nutrient sequestration, flood prevention, and habitat sanctuaries. However, nutrient loading can reduce habitat effectiveness and promote harmful algae blooms. To reduce internal nutrient loads, a biological-chemical treatment strategy consisting of floating treatment wetlands (FTWs) and lanthanum were applied to two urban retention ponds, Densmore and Wilderness Ridge Ponds. To measure effectiveness, chlorophyll-a samples were collected and correlated with Sentinel-2. A novel band algorithm termed 3BR1 produced a strong correlation (R2 = 0.72) to physical chlorophyll-a …


Coupling Dendroecological And Remote Sensing Techniques To Assess The Biophysical Traits Of Juniperus Virginiana And Pinus Ponderosa Within The Semi-Arid Grasslands Of The Nebraska Sandhills, R. Allen, Anastasios Mazis, Brian Wardlow, P. Cherubini, J. Hiller, David A. Wedin, Tala Awada Jun 2023

Coupling Dendroecological And Remote Sensing Techniques To Assess The Biophysical Traits Of Juniperus Virginiana And Pinus Ponderosa Within The Semi-Arid Grasslands Of The Nebraska Sandhills, R. Allen, Anastasios Mazis, Brian Wardlow, P. Cherubini, J. Hiller, David A. Wedin, Tala Awada

School of Natural Resources: Faculty Publications

Woody species encroachment is occurring within the semi-arid grasslands of the Nebraska Sandhills U.S., primarily driven by native Juniperus virginiana and Pinus ponderosa, altering ecosystems and the services they provide. Effective, low cost, and cross-scale monitoring of woody species growth and performance is necessary for integrated grassland and forest management in the face of climate variability and change. In this study, we sought to establish a relationship between remote sensing-derived vegetation indices (VIs), tree dendrochronological (raw and standardized tree ring width) measurements, and the abiotic environment [(precipitation, temperature, Palmer Drought Severity Index (PDSI), and soil water content (0–300 cm …


Revisiting The Carbon–Biodiversity Connection, John Gamon Jan 2023

Revisiting The Carbon–Biodiversity Connection, John Gamon

School of Natural Resources: Faculty Publications

This article is a Commentary on Schuldt et al., https://doi.org/10.1111/gcb.16697

The link between biodiversity and ecosystem function has long been a subject of intense interest and debate among biologists, going back to the time of Charles Darwin, whose ideas on species interactions presaged subsequent discussions of biodiversity and ecosystem function (Peterson et al., 1998). Since then, many considerations of community diversity have centered on the importance of species or functional diversity for maintaining system resilience in the face of disturbance, analogous to the way that interwoven threads maintain the function and integrity of fabric. While our language, concepts, and methods …


A Workshop On Using Nasa Airs Data To Monitor Drought For The U.S. Drought Monitor, Alireza Farahmand,, Sharon Ray, Heidar Thrastarson, Stephen Licata, Stephanie Granger, Brian Fuchs Jan 2023

A Workshop On Using Nasa Airs Data To Monitor Drought For The U.S. Drought Monitor, Alireza Farahmand,, Sharon Ray, Heidar Thrastarson, Stephen Licata, Stephanie Granger, Brian Fuchs

Drought Mitigation Center: Faculty Publications

Recent studies indicate that drought indicators based on near-surface air relative humidity (RH), air temperature (T), and air vapor pressure deficit (VPD), derived from the Atmospheric Infrared Sounder (AIRS) instrument aboard NASA’s Aqua satellite can detect the onset of drought earlier than other drought indicators, specifically standardized precipitation index (SPI), which is widely used for drought onset detection. A recent study showed that standardized relative humidity index (SRHI) can detect drought signals earlier than SPI (Farahmand et al. 2015). Relative humidity is a climate variable defined as the ratio of air vapor pressure to saturated vapor pressure. Precipitation and relative …


Coupling Dendrochronology And Remote Sensing Techniques To Assess The Biophysical Traits Of Juniperus Virginiana And Pinus Ponderosa Within Grassland Communities In The Semi-Arid Grasslands Of The Nebraska Sandhills, Reece Allen Jul 2022

Coupling Dendrochronology And Remote Sensing Techniques To Assess The Biophysical Traits Of Juniperus Virginiana And Pinus Ponderosa Within Grassland Communities In The Semi-Arid Grasslands Of The Nebraska Sandhills, Reece Allen

School of Natural Resources: Dissertations, Theses, and Student Research

Woody species encroachment is occurring within the sandhills region in Nebraska, primarily driven by Juniperus virginiana and Pinus ponderosa, altering ecosystems and the services they provide. Effective, low cost, and cross-scale monitoring of woody species growth and performance is necessary for integrated grassland and forest management in the face of climate variability and change. In this study, we sought to establish a relationship between remote sensing-derived vegetation indices (VIs) and dendrochronological (raw and standardized tree ring width) measurements to assess the performance of encroaching woody J. virginiana and P. ponderosa located within the Nebraska National Forest in the sandhills. …


Multi-Criteria Evaluation Model For Classifying Marginal Cropland In Nebraska Using Historical Crop Yield And Biophysical Characteristics, Andrew Laws May 2022

Multi-Criteria Evaluation Model For Classifying Marginal Cropland In Nebraska Using Historical Crop Yield And Biophysical Characteristics, Andrew Laws

School of Natural Resources: Dissertations, Theses, and Student Research

Marginal cropland is suboptimal due to historically low and variable productivity and limiting biophysical characteristics. To support future agricultural management and policy decisions in Nebraska, U.S.A, it is important to understand where cropland is marginal for its two most economically important crops: corn (Zea mays) and soybean (Glycine max). As corn and soybean are frequently planted in a crop rotation, it is important to consider if there is a relationship with cropland marginality. Based on the current literature, there exists a need for a flexible yet robust methodology for identifying marginal land at different scales, which …


Canopy Spectral Reflectance Detects Oak Wilt At The Landscape Scale Using Phylogenetic Discrimination, Gerard Sapes, Cathleen Lapadat, Anna K. Schweiger, Jennifer Juzwik, Rebecca Montgomery, Hamed Gholizadeh, Philip A. Townsend, John A. Gamon, Jeannine Cavender-Bares Mar 2022

Canopy Spectral Reflectance Detects Oak Wilt At The Landscape Scale Using Phylogenetic Discrimination, Gerard Sapes, Cathleen Lapadat, Anna K. Schweiger, Jennifer Juzwik, Rebecca Montgomery, Hamed Gholizadeh, Philip A. Townsend, John A. Gamon, Jeannine Cavender-Bares

School of Natural Resources: Faculty Publications

The oak wilt disease caused by the invasive fungal pathogen Bretziella fagacearum is one of the greatest threats to oak-dominated forests across the Eastern United States. Accurate detection and monitoring over large areas are necessary for management activities to effectively mitigate and prevent the spread of oak wilt. Canopy spectral reflectance contains both phylogenetic and physiological information across the visible near-infrared (VNIR) and short-wave infrared (SWIR) ranges that can be used to identify diseased red oaks. We develop partial least square discriminant analysis (PLS-DA) models using airborne hyperspectral reflectance to detect diseased canopies and assess the importance of VNIR, SWIR, …


Recent Advances Toward Transparent Methane Emissions Monitoring: A Review, Broghan M. Erland, Andrew K. Thorpe, John Gamon Jan 2022

Recent Advances Toward Transparent Methane Emissions Monitoring: A Review, Broghan M. Erland, Andrew K. Thorpe, John Gamon

Department of Earth and Atmospheric Sciences: Faculty Publications

Given that anthropogenic greenhouse gas (GHG) emissions must be immediately reduced to avoid drastic increases in global temperature, methane emissions have been placed center stage in the fight against climate change. Methane has a significantly larger warming potential than carbon dioxide. A large percentage of methane emissions are in the form of industry emissions, some of which can now be readily identified and mitigated. This review considers recent advances in methane detection that allow accurate and transparent monitoring, which are needed for reducing uncertainty in source attribution and evaluating progress in emissions reductions. A particular focus is on complementary methods …


Groundwater Level Assessment And Prediction In The Nebraska Sand Hills Using Lidar-Derived Lake Water Level, Nawaraj Shrestha, Aaron R. Mittelstet, Aaron R. Young, Troy E. Gilmore, David C. Gosselin, Yi Qi, Caner Zeyrek Jun 2021

Groundwater Level Assessment And Prediction In The Nebraska Sand Hills Using Lidar-Derived Lake Water Level, Nawaraj Shrestha, Aaron R. Mittelstet, Aaron R. Young, Troy E. Gilmore, David C. Gosselin, Yi Qi, Caner Zeyrek

School of Natural Resources: Faculty Publications

The spatial variability of groundwater levels is often inferred from sparsely located hydraulic head observations in wells. The spatial correlation structure derived from sparse observations is associated with uncertainties that spread to estimates at unsampled locations. In areas where surface water represents the nearby groundwater level, remote sensing techniques can estimate and increase the number of hydraulic head measurements. This research uses light detection and ranging (LIDAR) to estimate lake surface water level to characterize the groundwater level in the Nebraska Sand Hills (NSH), an area with few observation wells. The LIDAR derived lake groundwater level accuracy was within 40 …


Aquatic Habitat Changes Within The Channelized And Impounded Arkansas River, Arkansas, Usa, Jonathan J. Spurgeon, Mike Rhodes, J. Wesley Neal, Kristine O. Evans Jan 2021

Aquatic Habitat Changes Within The Channelized And Impounded Arkansas River, Arkansas, Usa, Jonathan J. Spurgeon, Mike Rhodes, J. Wesley Neal, Kristine O. Evans

School of Natural Resources: Faculty Publications

River-wide changes in morphologic character following channelization and impoundment alter the occurrence and distribution of surface water and available habitats for aquatic organisms. Quantifying patterns of creation, redistribution or disappearance of habitats at river-wide and decadal spatiotemporal scales can promote understanding regarding trajectories of different habitat types following alteration and prospects of direct habitat enhancement projects within altered alluvial rivers. Newly available remote-sensing tools and databases may improve detection of river-wide changes in habitat through time. We used a combination of remote-sensing data and generalized linear models to assess changes in surface water coverage from 1984 to 2015 among aquatic …


Evaluation Of Remotely Sensed Precipitation Estimates From The Nasa Power Project For Drought Detection Over Jordan, Muhammad Rasool Al‑Kilani, Michel Rahbeh, Jawad Al‑Bakri, Tsegaye Tadesse, Cody Knutson Jan 2021

Evaluation Of Remotely Sensed Precipitation Estimates From The Nasa Power Project For Drought Detection Over Jordan, Muhammad Rasool Al‑Kilani, Michel Rahbeh, Jawad Al‑Bakri, Tsegaye Tadesse, Cody Knutson

Drought Mitigation Center: Faculty Publications

Droughts can cause devastating impacts on water and land resources and therefore monitoring these events forms an integral part of planning. The most common approach for detecting drought events and assessing their intensity is use of the Standardized Precipitation Index (SPI), which requires abundant precipitation records at good spatial distribution. This may restrict SPI usage in many regions around the world, particularly in areas with limited numbers of ground meteorological stations. Therefore, the use of remotely sensed derived data of precipitation can contribute to drought monitoring. In this study, remotely sensed precipitation estimates from the POWER/Agroclimatology archive of NASA and …


Remote Sensing And Three-Dimensional Photogrammetric Analysis Of Glaciofluvial Sand And Gravel Deposits For Aggregate Resource Assessment In Mchenry County, Illinois, Usa, Xiaodong Miao, Christopher J. Stohr, Paul R. Hanson, Qiansuo Wang Jun 2020

Remote Sensing And Three-Dimensional Photogrammetric Analysis Of Glaciofluvial Sand And Gravel Deposits For Aggregate Resource Assessment In Mchenry County, Illinois, Usa, Xiaodong Miao, Christopher J. Stohr, Paul R. Hanson, Qiansuo Wang

School of Natural Resources: Faculty Publications

Sand and gravel deposits, one of the most common natural resources, are used as aggregates mostly by the construction industry, and their extraction contributes significantly to a region's economy. Thus, it is critical to locate sand and gravel deposits, and evaluate their quantity and quality safely and quickly. However, information on aggregate resources is generally only available from conventional two-dimensional (2-D) geologic maps, and direct field measurements for quality analysis at outcrops are time consuming and are often not possible due to safety concerns, or simply because exposures are too difficult to access. In this study, we presented a methodology …


Extreme Fire As A Management Tool To Combat Regime Shifts In The Range Of The Endangered American Burying Beetle, Alison K. Ludwig, Daniel R. Uden, Dirac Twidwell Apr 2020

Extreme Fire As A Management Tool To Combat Regime Shifts In The Range Of The Endangered American Burying Beetle, Alison K. Ludwig, Daniel R. Uden, Dirac Twidwell

Department of Agronomy and Horticulture: Dissertations, Theses, and Student Research

This study is focused on the population of federally-endangered American burying beetles in south-central Nebraska. It is focused on changes in land cover over time and at several levels of spatial scale, and how management efforts are impacting both the beetle and a changing landscape. Our findings are applicable to a large portion of the Great Plains, which is undergoing the same shift from grassland to woodland, and to areas where the beetle is still found.


Leaf Reflectance Spectra Capture The Evolutionary History Of Seed Plants, Jose Eduardo Meireles, Jeannine Cavender-Bares, Philip A. Townsend, Susan Ustin, John A. Gamon, Anna K. Schweiger, Michael E. Schaepman, Gregory P. Asner, Roberta E. Martin, Aditya Singh, Franziska Schrodt, Adam Chlus, Brian C. O’Meara Jan 2020

Leaf Reflectance Spectra Capture The Evolutionary History Of Seed Plants, Jose Eduardo Meireles, Jeannine Cavender-Bares, Philip A. Townsend, Susan Ustin, John A. Gamon, Anna K. Schweiger, Michael E. Schaepman, Gregory P. Asner, Roberta E. Martin, Aditya Singh, Franziska Schrodt, Adam Chlus, Brian C. O’Meara

School of Natural Resources: Faculty Publications

  • Leaf reflection spectra have been increasingly used to assess plant diversity. However, we do not yet understand how spectra vary across the tree of life or how the evolution of leaf traits affects the differentiation of spectra among species and lineages.
  • Here we describe a framework that integrates spectra with phylogenies and apply it to aglobal dataset of over 16 000 leaf-level spectra (400–2400 nm) for 544 seed plant species. We test for phylogenetic signal in spectra, evaluate their ability to classify lineages, and characterize their evolutionary dynamics.
  • We show that phylogenetic signal is present in leaf spectra but that …


Czech Drought Monitor System For Monitoring And Forecasting Of Agricultural Drought And Drought Impacts, Miroslav Trnka, Petr Hlavinka, Martin Možný, Daniela Semerádová, Petr Štěpánek, Jan Balek, Lenka Bartošová, Pavel Zahradníček, Monika Bláhová, Petr Skalák, Aleš Farda, Michael Hayes, Mark D. Svoboda, Wolfgang Wagner, Josef Eitzinger, Milan Fischer, Zdeněk Zalud Jan 2020

Czech Drought Monitor System For Monitoring And Forecasting Of Agricultural Drought And Drought Impacts, Miroslav Trnka, Petr Hlavinka, Martin Možný, Daniela Semerádová, Petr Štěpánek, Jan Balek, Lenka Bartošová, Pavel Zahradníček, Monika Bláhová, Petr Skalák, Aleš Farda, Michael Hayes, Mark D. Svoboda, Wolfgang Wagner, Josef Eitzinger, Milan Fischer, Zdeněk Zalud

School of Natural Resources: Faculty Publications

The awareness of drought and its impacts on Central Europe increased after the significant drought episodes in 2000, 2003, 2012 and 2015, which were all estimated to have caused over 500 million Euro in damage in the Czech Republic alone. These events indicated the need for timely and highresolution monitoring tools that would enable analysing, monitoring and forecasting of drought events. Monitoring soil water availability in near real time and at high-resolution (up to 0.5 × 0.5 km for some products) helps farmers and water managers to mitigate impacts of these extreme events. The Czech Drought Monitor was developed between …


A Review Of Drought Monitoring Using Remote Sensing And Data Mining Methods, R. Inoubli, A.B. Abbes, I.R. Farah, V. Singh, T. Tadesse, A.Z. Abiy Jan 2020

A Review Of Drought Monitoring Using Remote Sensing And Data Mining Methods, R. Inoubli, A.B. Abbes, I.R. Farah, V. Singh, T. Tadesse, A.Z. Abiy

School of Natural Resources: Faculty Publications

No abstract provided.


Beyond Inventories: Emergence Of A New Era In Rangeland Monitoring, Matthew O. Jones, David E. Naugle, Dirac Twidwell, Daniel R. Uden, Jeremy D. Maestas, Brady W. Allred Jan 2020

Beyond Inventories: Emergence Of A New Era In Rangeland Monitoring, Matthew O. Jones, David E. Naugle, Dirac Twidwell, Daniel R. Uden, Jeremy D. Maestas, Brady W. Allred

School of Natural Resources: Faculty Publications

In the absence of technology-driven monitoring platforms, US rangeland policies, management practices, and outcome assessments have been primarily informed by the extrapolation of local information from national-scale rangeland inventories. A persistent monitoring gap between plot-level inventories and the scale at which rangeland assessments are conducted has required decision makers to fill data gaps with statistical extrapolations or assumptions of homogeneity and equilibrium. This gap is now being bridged with spatially comprehensive, annual, rangeland monitoring data across all western US rangelands to as- sess vegetation conditions at a resolution appropriate to inform cross-scale assessments and decisions. In this paper, 20-yr trends …


Current Frameworks For Reference Et And Crop Coefficient Calculation, R G. Allen, Ayse Kilic, Clarence W. Robison Jan 2020

Current Frameworks For Reference Et And Crop Coefficient Calculation, R G. Allen, Ayse Kilic, Clarence W. Robison

School of Natural Resources: Faculty Publications

Estimation of evapotranspiration is under continual development and evolution, with significant developments and standardizations made during the past three decades for both reference ET (ETref) and for crop coefficients (Kc). These standardizations provide consistency and reproducibility in estimating ETref and a consistent basis for determining and expressing Kc curves, especially at the local scale. The application of the dual Kc procedure is growing, and has strong potential for improving accuracy of ET estimates as compared to the single Kc approach. This article describes current structures for estimating crop coefficients including the standardized FAO-56 dual Kc approach, with example applications. Emphasis …


Metric-Gis: An Advanced Energy Balance Model For Computing Crop Evapotranspiration In A Gis Environment, J. M. Ramírez-Cuesta, R G. Allen, D. S. Intrigliolo, Ayse Kilic, Clarence W. Robison, Ricardo Trezza, C. Santos, I. J. Lorite Jan 2020

Metric-Gis: An Advanced Energy Balance Model For Computing Crop Evapotranspiration In A Gis Environment, J. M. Ramírez-Cuesta, R G. Allen, D. S. Intrigliolo, Ayse Kilic, Clarence W. Robison, Ricardo Trezza, C. Santos, I. J. Lorite

School of Natural Resources: Faculty Publications

A novel ArcGIS toolbox that applies the Mapping Evapotranspiration with Internalized Calibration model was developed and tested in a semi-arid environment. The tool, named METRIC-GIS, facilitates the pre-processing operations and the automatic identification of potential calibration and pixels review. The energy balance components obtained from METRIC-GIS were contrasted with those from the original METRIC version (R2 = 1; RMSE = 0 W m–2 or mm day–1 for ETc) Additionally, an irrigated scheme located at southern Spain was considered for assessing Kc variability in the maize fields with METRIC-GIS. The identified spatial variability was mainly due …


A Review Of Vegetation Phenological Metrics Extraction Using Time-Series, Multispectral Satellite Data, Linglin Zeng, Brian D. Wardlow, Daxiang Xiang, Shun Hu, Deren Li Jan 2020

A Review Of Vegetation Phenological Metrics Extraction Using Time-Series, Multispectral Satellite Data, Linglin Zeng, Brian D. Wardlow, Daxiang Xiang, Shun Hu, Deren Li

School of Natural Resources: Faculty Publications

Vegetation dynamics and phenology play an important role in inter-annual vegetation changes in terrestrial ecosystems and are key indicators of climate-vegetation interactions, land use/land cover changes, and variation in year-to-year vegetation productivity. Satellite remote sensing data have been widely used for vegetation phenology monitoring over large geographic domains using various types of observations and methods over the past several decades. The goal of this paper is to present a detailed review of existing methods for phenology detection and emerging new techniques based on the analysis of time-series, multispectral remote sensing imagery. This paper summarizes the objective and applications of detecting …


Improving The Accessibility And Transferability Of Machine Learning Algorithms For Identification Of Animals In Camera Trap Images: Mlwic2, Michael A. Tabak, Mohammad S. Norouzzadeh, David W. Wolfson, Erica J. Newton, Raoul K. Boughton, Jacob S. Ivan, Eric Odell, Eric S. Newkirk, Reesa Y. Conrey, Jennifer Stenglein, Fabiola Iannarilli, John Erb, Ryan K. Brook, Amy J. Davis, Jesse Lewis, Daniel P. Walsh, James C. Beasley, Kurt C. Vercauteren, Jeff Clune, Ryan S. Miller Jan 2020

Improving The Accessibility And Transferability Of Machine Learning Algorithms For Identification Of Animals In Camera Trap Images: Mlwic2, Michael A. Tabak, Mohammad S. Norouzzadeh, David W. Wolfson, Erica J. Newton, Raoul K. Boughton, Jacob S. Ivan, Eric Odell, Eric S. Newkirk, Reesa Y. Conrey, Jennifer Stenglein, Fabiola Iannarilli, John Erb, Ryan K. Brook, Amy J. Davis, Jesse Lewis, Daniel P. Walsh, James C. Beasley, Kurt C. Vercauteren, Jeff Clune, Ryan S. Miller

USDA Wildlife Services: Staff Publications

Motion-activated wildlife cameras (or “camera traps”) are frequently used to remotely and noninvasively observe animals. The vast number of images collected from camera trap projects has prompted some biologists to employ machine learning algorithms to automatically recognize species in these images, or at least filter-out images that do not contain animals. These approaches are often limited by model transferability, as a model trained to recognize species from one location might not work as well for the same species in different locations. Furthermore, these methods often require advanced computational skills, making them inaccessible to many biologists. We used 3 million camera …


The Role Of Topography, Soil, And Remotely Sensed Vegetation Condition Towards Predicting Crop Yield, Trenton E. Franz, Sayli Pokal, Justin P. Gibson, Yuzhen Zhou, Hamed Gholizadeh, Fatima Amor Tenorio, Daran Rudnick, Derek M. Heeren, Matthew F. Mccabe, Matteo Ziliani, Zhenong Jin, Kaiyu Guan, Ming Pan, John Gates, Brian Wardlow Jan 2020

The Role Of Topography, Soil, And Remotely Sensed Vegetation Condition Towards Predicting Crop Yield, Trenton E. Franz, Sayli Pokal, Justin P. Gibson, Yuzhen Zhou, Hamed Gholizadeh, Fatima Amor Tenorio, Daran Rudnick, Derek M. Heeren, Matthew F. Mccabe, Matteo Ziliani, Zhenong Jin, Kaiyu Guan, Ming Pan, John Gates, Brian Wardlow

School of Natural Resources: Faculty Publications

Foreknowledge of the spatiotemporal drivers of crop yield would provide a valuable source of information to optimize on-farm inputs and maximize profitability. In recent years, an abundance of spatial data providing information on soils, topography, and vegetation condition have become available from both proximal and remote sensing platforms. Given the wide range of data costs (between USD $0−50/ha), it is important to understand where often limited financial resources should be directed to optimize field production. Two key questions arise. First, will these data actually aid in better fine-resolution yield prediction to help optimize crop management and farm economics? Second, what …


Use Of Uav Imagery And Nutrient Analyses For Estimation Of The Spatial And Temporal Contributions Of Cattle Dung To Nutrient Cycling In Grazed Ecosystems, Amanda Shine Dec 2019

Use Of Uav Imagery And Nutrient Analyses For Estimation Of The Spatial And Temporal Contributions Of Cattle Dung To Nutrient Cycling In Grazed Ecosystems, Amanda Shine

Department of Agronomy and Horticulture: Dissertations, Theses, and Student Research

Nutrient inputs from cattle dung are crucial drivers of nutrient cycling processes in grazed ecosystems. These inputs are important both spatially and temporally and are affected by variables such as grazing strategy, water location, and the nutritional profile of forage being grazed. Past research has attempted to map dung deposition patterns in order to more accurately estimate nutrient input, but the large spatial extent of a typical pasture and the tedious nature of identifying and mapping individual dung pats has prohibited the development of a time- and cost-effective methodology. The first objective of this research was to develop and validate …


Satellite-Based Decadal Change Assessments Of Pan-Arctic Environments, Liza K. Jenkins, Tom Barry, Karl R. Bosse, William S. Currie, Tom Christensen, Sara Longan, Robert A. Shuchman, Danielle Tanzer, Jason J. Taylor Nov 2019

Satellite-Based Decadal Change Assessments Of Pan-Arctic Environments, Liza K. Jenkins, Tom Barry, Karl R. Bosse, William S. Currie, Tom Christensen, Sara Longan, Robert A. Shuchman, Danielle Tanzer, Jason J. Taylor

United States National Park Service: Publications

Remote sensing can advance the work of the Circumpolar Biodiversity Monitoring Program through monitoring of satellite-derived terrestrial and marine physical and ecological variables. Standardized data facilitate an unbiased comparison across variables and environments. Using MODIS standard products of land surface temperature, percent snow-covered area, NDVI, EVI, phenology, burned area, marine chlorophyll, CDOM, sea surface temperature, and marine primary productivity, significant trends were observed in almost all variables between 2000 and 2017. Analysis of seasonal data revealed significant breakpoints in temporal trends. Within the terrestrial environment, data showed significant increasing trends in land surface temperature and NDVI. In the marine environment, …


Drought Impacts Assessment In Brazil - A Remote Sensing Approach, Denis Mariano Aug 2019

Drought Impacts Assessment In Brazil - A Remote Sensing Approach, Denis Mariano

School of Natural Resources: Dissertations, Theses, and Student Research

Climate extremes are becoming more frequent in Brazil; studies project an increase in drought occurrences in many regions of the country. In the south, drought events lead to crop yield losses affecting the value chain and, therefore, the local economy. In the northeast, extended periods of drought lead to potential land degradation, affecting the livelihood and hindering local development. In the southern Amazon, an area that experienced intense land use change (LUC) in the last, the impacts are even more complex, ranging from crop yield loss and forest resilience loss, affecting ecosystem health and putting a threat on the native …


Spectrally Based Bathymetric Mapping Of A Dynamic, Sandbedded Channel: Niobrara River, Nebraska, Usa, E. Dilbone, C.J. Legleiter, J.S. Alexander, B. Mcelroy Feb 2018

Spectrally Based Bathymetric Mapping Of A Dynamic, Sandbedded Channel: Niobrara River, Nebraska, Usa, E. Dilbone, C.J. Legleiter, J.S. Alexander, B. Mcelroy

United States Geological Survey: Staff Publications

Methods for spectrally based mapping of river bathymetry have been developed and tested in clear‐flowing, gravel‐bed channels, with limited application to turbid, sandbed rivers. This study used hyperspectral images and field surveys from the dynamic, sandy Niobrara River to evaluate three depth retrieval methods. The first regressionbased approach, optimal band ratio analysis (OBRA), paired in situ depth measurements with image pixel values to estimate depth. The second approach used ground‐based field spectra to calibrate an OBRA relationship. The third technique, image‐to‐depth quantile transformation (IDQT), estimated depth by linking the cumulative distribution function (CDF) of depth to the CDF of an …


The Spatial Sensitivity Of The Spectral Diversity–Biodiversity Relationship: An Experimental Test In A Prairie Grassland, Ran Wang, John A. Gamon, Jeannine Cavender-Bares, Philip A. Townsend, Arthur I. Zygielbaum Jan 2018

The Spatial Sensitivity Of The Spectral Diversity–Biodiversity Relationship: An Experimental Test In A Prairie Grassland, Ran Wang, John A. Gamon, Jeannine Cavender-Bares, Philip A. Townsend, Arthur I. Zygielbaum

School of Natural Resources: Faculty Publications

Remote sensing has been used to detect plant biodiversity in a range of ecosystems based on the varying spectral properties of different species or functional groups. However, the most appropriate spatial resolution necessary to detect diversity remains unclear. At coarse resolution, differences among spectral patterns may be too weak to detect. In contrast, at fine resolution, redundant information may be introduced. To explore the effect of spatial resolution, we studied the scale dependence of spectral diversity in a prairie ecosystem experiment at Cedar Creek Ecosystem Science Reserve, Minnesota, USA. Our study involved a scaling exercise comparing synthetic pixels resampled from …


The Spatial Sensitivity Of The Spectral Diversity–Biodiversity Relationship: An Experimental Test In A Prairie Grassland, Ran Wang, John A. Gamon, Jeannine Cavender-Bares, Philip A. Townsend, Arthur I. Zygielbaum Jan 2018

The Spatial Sensitivity Of The Spectral Diversity–Biodiversity Relationship: An Experimental Test In A Prairie Grassland, Ran Wang, John A. Gamon, Jeannine Cavender-Bares, Philip A. Townsend, Arthur I. Zygielbaum

School of Natural Resources: Faculty Publications

Remote sensing has been used to detect plant biodiversity in a range of ecosystems based on the varying spectral properties of different species or functional groups. However, the most appropriate spatial resolution necessary to detect diversity remains unclear. At coarse resolution, differences among spectral patterns may be too weak to detect. In contrast, at fine resolution, redundant information may be introduced. To explore the effect of spatial resolution, we studied the scale dependence of spectral diversity in a prairie ecosystem experiment at Cedar Creek Ecosystem Science Reserve, Minnesota, USA. Our study involved a scaling exercise comparing synthetic pixels resampled from …


Drought And Land-Cover Conditions In The Great Plains, Heather Tollerud, Jesslyn Brown, Thomas Loveland, Rezaul Mahmood, Norman Bliss Jan 2018

Drought And Land-Cover Conditions In The Great Plains, Heather Tollerud, Jesslyn Brown, Thomas Loveland, Rezaul Mahmood, Norman Bliss

HPRCC Personnel Publications

Land–atmosphere interactions play a critical role in the Earth system, and a better understanding of these interactions could improve weather and climate models. The interaction among drought, vegetation productivity, and land cover is of particular significance. In a semiarid environment, such as the U.S. Great Plains, droughts can have a large influence on the productivity of agriculture and grasslands, with serious environmental and economic impacts. Here, we used the vegetation drought response index (VegDRI) drought indicator to investigate the response of vegetation to weather and climate for landcover types in the Great Plains in the United States from 1989 to …


Utilizing A Consumer-Grade Camera System To Quantify Surface Reflectance, Joseph J. Lehnert Aug 2017

Utilizing A Consumer-Grade Camera System To Quantify Surface Reflectance, Joseph J. Lehnert

Department of Geography: Dissertations, Theses, and Student Research

Consumer-grade camera systems are often employed in aerial remote sensing to provide insight into patterns and processes of interest to science and industry, a trend that has largely been encouraged by the rapid growth of the small unmanned aircraft system (sUAS) industry. However, little research exists on the ability of these systems to accurately measure surface reflectance in specific wavebands, a crucial consideration for many remote sensing applications. This research was conducted on the premise that with proper equipment and calibration techniques consumer-grade cameras would be capable of accurately measuring surface reflectance in user-defined wavebands of interest. A stereo-pair, Fujifilm …