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- Department of Agronomy and Horticulture: Dissertations, Theses, and Student Research (2)
- Mathematics, Physics, and Computer Science Faculty Articles and Research (2)
- Biosystems and Agricultural Engineering Faculty Publications (1)
- Department of Plant Pathology: Faculty Publications (1)
- OES Faculty Publications (1)
Articles 1 - 12 of 12
Full-Text Articles in Physical Sciences and Mathematics
The Vulnerability And Resilience Of Seagrass Ecosystems To Marine Heatwaves In New Zealand: A Remote Sensing Analysis Of Seascape Metrics Using Planetscope Imagery, Ken Joseph E. Clemente, Mads S. Thomsen, Richard C. Zimmerman
The Vulnerability And Resilience Of Seagrass Ecosystems To Marine Heatwaves In New Zealand: A Remote Sensing Analysis Of Seascape Metrics Using Planetscope Imagery, Ken Joseph E. Clemente, Mads S. Thomsen, Richard C. Zimmerman
OES Faculty Publications
Seagrasses are foundation species that provide ecosystem functions and services, including increased biodiversity, sediment retention, carbon sequestration, and fish nursery habitat. However, anthropogenic stressors that reduce water quality, impose large-scale climate changes, and amplify weather patterns, such as marine heatwaves, are altering seagrass meadow configurations. Quantifying large-scale trends in seagrass distributions will help evaluate the impacts of climate drivers on their functions and services. Here, we quantified spatiotemporal dynamics in abundances and configurations of intertidal and shallow subtidal seagrass (Zostera muelleri) meadows in 20 New Zealand (NZ) estuaries that span a 5-year period (mid/late 2016–early 2022) just before, …
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
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.
Evaluating Potential Effects Of 2019 Australian Bushfires On Animal Species, Protected Land, And Land Cover, Alyssa J. Kaewwilai
Evaluating Potential Effects Of 2019 Australian Bushfires On Animal Species, Protected Land, And Land Cover, Alyssa J. Kaewwilai
Student Publications
The 2019-2020 Australian bushfire event had exceptionally dry, hot conditions as well as high potential impacts on the country’s wildlife and natural resources. The purpose of the study was to analyze the potential impacts of the 2019 Australian bushfire event on animal species, protected land, and varied land cover types. The research question of this project is: how does the location of the Australian Bushfires of 2020 potentially impact animal species, protected land and national parks, as well as different land covers? Raster calculator was used to combine and classify layers from the MODIS Burned Area Product of burned (1) …
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 …
Estimating Live Fuel Moisture In Southern California Using Remote Sensing Vegetation Water Content Proxies, Shenyue Jia, Seung Hee Kim, Son V. Nghiem, Wonhee Cho, Menas Kafatos
Estimating Live Fuel Moisture In Southern California Using Remote Sensing Vegetation Water Content Proxies, Shenyue Jia, Seung Hee Kim, Son V. Nghiem, Wonhee Cho, Menas Kafatos
Mathematics, Physics, and Computer Science Faculty Articles and Research
Wildfires are a major ecological disturbance in Southern California and often lead to great destruction along the Wildland-Urban Interface. Live fuel moisture has been used as an important indicator of wildfire risk in measurements of vegetation water content. However, the limited field measurements of live fuel moisture in both time and space have affected the accuracy of wildfire risk estimations. Traditional estimation of live fuel moisture using remote sensing data was based on vegetation indices, indirect proxies of vegetation water content and subject to influence from weather conditions. In this study, we investigated the feasibility of estimating live fuel moisture …
A Method For Reflectance Index Wavelength Selection From Moisture-Controlled Soil And Crop Residue Samples, Ali Hamidisepehr, Michael P. Sama, Aaron P. Turner, Ole O. Wendroth
A Method For Reflectance Index Wavelength Selection From Moisture-Controlled Soil And Crop Residue Samples, Ali Hamidisepehr, Michael P. Sama, Aaron P. Turner, Ole O. Wendroth
Biosystems and Agricultural Engineering Faculty Publications
Reflectance indices are a method for reducing the dimensionality of spectral measurements used to quantify material properties. Choosing the optimal wavelengths for developing an index based on a given material and property of interest is made difficult by the large number of wavelengths typically available to choose from and the lack of homogeneity when remotely sensing agricultural materials. This study aimed to determine the feasibility of using a low-cost method for sensing the moisture content of background materials in traditional crop remote sensing. Moisture-controlled soil and wheat stalk residue samples were measured at varying heights using a reflectance probe connected …
Developing The Framework For A Risk Map For Mite Vectored Viruses In Wheat Resulting From Pre-Harvest Hail Damage, Anthony L. Nguy-Robertson, Arthur Zygielbaum, Anthony J. Mcmechan, Gary L. Hein, Stephen N. Wegulo, Abby R. Stilwell, Travis M. Smith
Developing The Framework For A Risk Map For Mite Vectored Viruses In Wheat Resulting From Pre-Harvest Hail Damage, Anthony L. Nguy-Robertson, Arthur Zygielbaum, Anthony J. Mcmechan, Gary L. Hein, Stephen N. Wegulo, Abby R. Stilwell, Travis M. Smith
Department of Plant Pathology: Faculty Publications
There is a strong economic incentive to reduce mite-vectored virus outbreaks. Most outbreaks in the central High Plains of the United States occur in the presence of volunteer wheat that emerges before harvest as a result of hail storms. This study provides a conceptual framework for developing a risk map for wheat diseases caused by mite-vectored viruses based on pre-harvest hail events. Traditional methods that use NDVI were found to be unsuitable due to low chlorophyll content in wheat at harvest. Site-level hyperspectral reflectance from mechanically hailed wheat showed increased canopy albedo. Therefore, any increase in NIR combined with large …
Detection Of Temporal Changes In Vegetative Cover On South Padre Island, Texas Using Image Classifications Derived From Aerial Color-Infrared Photographs, Ruben A. Mazariegos, Kenneth R. Summy, Frank W. Judd, Robert I. Lonard, James H. Everitt
Detection Of Temporal Changes In Vegetative Cover On South Padre Island, Texas Using Image Classifications Derived From Aerial Color-Infrared Photographs, Ruben A. Mazariegos, Kenneth R. Summy, Frank W. Judd, Robert I. Lonard, James H. Everitt
Physics and Astronomy Faculty Publications and Presentations
Supervised image classifications developed from 23 x 23 cm aerial color-infrared aerial photographs (1:5,000 scale) were used to evaluate temporal changes in vegetative cover occurring within three 150 x 300-m research sites on South Padre Island, Texas. Use of high-resolution digitized imagery (ground pixel resolution of ca. 0.1 m) and survey-grade GPS for positional measurements of ground control points (20-25 1.0m2 targets within each research site) resulted in consistently high levels of geometric accuracy, with root mean square errors (RMSEs) ranging between 0.397 – 2.867. Similarly, use of relatively simple information categories (dry and wet sand, live and dead vegetative …
Chlorophyll-Based Approach For Remote Estimation Of Crop Gross Primary Production: From In Situ Measurements To Satellite Imagery, Yi Peng
School of Natural Resources: Dissertations, Theses, and Student Research
The synoptic and accurate quantification of crop gross primary production (GPP) is essential for studying carbon budgets in croplands and monitoring crop status. The objective of this dissertation is to develop a quantitative technique to estimate crop GPP using remotely sensed data collected from close range to satellite altitudes. In this study, a model based on a recently developed paradigm, which relates crop GPP to a product of total crop chlorophyll content and incident radiation affecting vegetation photosynthesis, was justified for the remote estimation of GPP in crops. The model was tested with ground-observed incoming photosynthetically active radiation (PARin …
Relating Surface Backscatter Response From Trmm Precipitation Radar To Soil Moisture: Results Over A Semi-Arid Region, Haroon Stephen, Sajjad Ahmad, Thomas C. Piechota, Chunling Tang
Relating Surface Backscatter Response From Trmm Precipitation Radar To Soil Moisture: Results Over A Semi-Arid Region, Haroon Stephen, Sajjad Ahmad, Thomas C. Piechota, Chunling Tang
Public Policy and Leadership Faculty Publications
The Tropical Rainfall Measuring Mission (TRMM) carries aboard the Precipitation Radar (TRMMPR) that measures the backscatter (σº) of the surface. σº is sensitive to surface soil moisture and vegetation conditions. Due to sparse vegetation in arid and semi-arid regions, TRMMPR σº primarily depends on the soil water content. In this study we relate TRMMPR σº measurements to soil water content (m(s)) in the Lower Colorado River Basin (LCRB). σº dependence on ms is studied for different vegetation greenness values determined through Normalized Difference Vegetation Index (NDVI). A new model of σº that couples incidence angle, m(s), and NDVI is used …
Using Local Knowledge And Remote Sensing To Map Known And Potential Prairie-Chicken Distribution In Kansas, Michael E. Houts, Randy D. Rodgers, Roger D. Applegate, William H. Busby
Using Local Knowledge And Remote Sensing To Map Known And Potential Prairie-Chicken Distribution In Kansas, Michael E. Houts, Randy D. Rodgers, Roger D. Applegate, William H. Busby
The Prairie Naturalist
The greater prairie-chicken (Tympanuchus cupido) and lesser prairie-chicken (Tympanuchus pallidicinctus) have experienced considerable fluctuations in their range and distribution over time. Having current range maps would help wildlife managers and policy makers with decisions regarding prairie-chicken habitat. To create an updated and accurate map of the Kansas prairie-chicken range, a two-pronged approach was implemented. First, a map of potential habitat was created by using known habitat preferences and avoidance factors. Second, a preliminary map showing the distribution of greater and lesser prairie-chickens was created and mailed to regional experts for comments and edits. The returned edits …
Correlation Between Atmospheric Co2 Concentration And Vegetation Greenness In North America: Co2 Fertilization Effect, C. Lim, Menas Kafatos, P. Megonigal
Correlation Between Atmospheric Co2 Concentration And Vegetation Greenness In North America: Co2 Fertilization Effect, C. Lim, Menas Kafatos, P. Megonigal
Mathematics, Physics, and Computer Science Faculty Articles and Research
The possibility that rising atmospheric CO2 concentrations are influencing plant growth in contemporary ecosystems has received little attention, and the studies that exist have been done on a small spatial scale. We correlated the monthly rate of relative change in normalized differenced vegetation index (NDVI) from advanced very high resolution radiometer (AVHRR) data to the rate of change in atmospheric CO2 concentration during the natural vegetation growing season for evidence of a possible CO2 fertilization effect on vegetation development. The study addressed seasonal and annual patterns in spatially averaged NDVI for 3 different ecological regions in North America from 1982 …