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Articles 601 - 630 of 1603

Full-Text Articles in Environmental Indicators and Impact Assessment

What, Where, Why: A Survey Of Felidae Populations At Enashiva Nature Refuge, Tanzania, Lucrecia Aguilar Apr 2017

What, Where, Why: A Survey Of Felidae Populations At Enashiva Nature Refuge, Tanzania, Lucrecia Aguilar

Independent Study Project (ISP) Collection

As felid populations worldwide continue to deteriorate due to human activities, understanding how felid species utilize various landscapes, along with what factors affect such use or disuse, becomes essential to the preservation of these species. While previous research has examined felid populations around the world, many species and locations remain understudied. This study surveyed felid species at Enashiva Nature Refuge (ENR) in the Serengeti-Mara ecosystem to determine (1) what felid species are present at ENR, (2) where these species generally occur, and (3) why felids reside at ENR in low or high numbers. Through the use of opportunistic camera trapping, …


Modeling Gross Primary Production Of Midwest Maize And Soybean Croplands With Satellite And Gridded Weather Data, Gunnar Malek-Madani Apr 2017

Modeling Gross Primary Production Of Midwest Maize And Soybean Croplands With Satellite And Gridded Weather Data, Gunnar Malek-Madani

Department of Geography: Dissertations, Theses, and Student Research

The gross primary production (GPP) metric is useful in determining trends in the terrestrial carbon cycle. Models that determine GPP utilizing the light use efficiency (LUE) approach in conjunction with biophysical parameters that account for local weather conditions and crop specific factors are beneficial in that they combine the accuracy of the biophysical model with the versatility of the LUE model. One such model developed using in situ data was adapted to operate with remote sensing derived leaf area index (LAI) data and gridded weather datasets. The model, known as the Light Use Efficiency GPP Model (EGM), uses a four …


The Coastal Monitor: Vol 2. No 1., John Tanacredi Ph.D. Apr 2017

The Coastal Monitor: Vol 2. No 1., John Tanacredi Ph.D.

The Coastal Monitor

There is something enchanting and vibrant about viewing the coast. Every day at CERCOM we are welcomed by either a vivid sunrise, a view of the barrier island Fire Island and a blending of the sky across the horizon, ultimately flooding the Great South Bay with either clouds or sunshine that reveals the Bay’s surface as either shimmering with sunlight, or an integration of sky and water as an endless ocean. I don’t normally wax poetic but the varying sights along the near shore ocean and this embayment beckon our scientific inquisitiveness. What’s below the surface water? How do animals …


A Web Based Real Time Nitrogen Leaching Calculator, Saeideh Samani, Babak Samani, Haishun Yang Apr 2017

A Web Based Real Time Nitrogen Leaching Calculator, Saeideh Samani, Babak Samani, Haishun Yang

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

While nitrogen (N) is an essential nutrient for corn, its leaching to ground water is an serious environmental issue and a hazard to public health. N leaching is closely linked to weather factors, especially rainfall. Prediction of N leaching in cropping systems is critical to improvement of crop management and reduction of N leaching. The objective of this project is to develop a web app that predicts in real-time mode N leaching across Nebraska using real-time weather data.

We are in the processing of developing the web app and expect a prototype to be running in 2017 cropping season. Field …


Homestead National Monument Of America, Bat Acoustic Monitoring, September 2016, Daniel S. Licht Mar 2017

Homestead National Monument Of America, Bat Acoustic Monitoring, September 2016, Daniel S. Licht

United States National Park Service: Publications

Abstract

Homestead National Monument of America is a 211-acre park located in an agrarian landscape in southeastern Nebraska. From September 16 to October 1, 2016, park staff deployed acoustic monitors at three sites in the park for purposes of monitoring night-time bat activity. The three sites averaged 179, 48, and 33 bat detections per night. Night-time bat activity was generally highest in the 1-2 hours following sunset.

Based on the acoustic surveys the big brown (Eptesicus fuscus), eastern red (Lasiurus borealis), northern long-eared (Myotis septentrionalis) and evening bats (Nycticeius humeralis) were present at the …


Composition And Quantification Of Polycyclic Aromatic Hydrocarbons In Deep-Pelagic Fauna, Cruises Dp01 And Dp02 From May 2015 - August 2015, Isabel C. Romero Feb 2017

Composition And Quantification Of Polycyclic Aromatic Hydrocarbons In Deep-Pelagic Fauna, Cruises Dp01 And Dp02 From May 2015 - August 2015, Isabel C. Romero

DEEPEND Datasets

This data set includes the biological PAH (Polycyclic Aromatic Hydrocarbons) data of target species collected during the DP01 (May 1-8, 2015) and DP02 cruises (August 8-21, 2015) in the Northern Gulf of Mexico. The target fish species include Ceratoscopelus warmingii, Chaulidus spp., Diaphus spp., Argyropelecus spp, Lampanyctus alatus, and Sigma elongatum. Also, analysis of shrimp (Acanthephyra purpurea) and cephalopod (Grimalditeuthis bonplandi, Histioteuthis corona, Japetella diaphana) samples were conducted. PAHs were analyzed following modified EPA method 8270D and QA/QC strict protocols. Detection and quantification of PAHs were performed using a gas chromatograph/mass spectrometric detector (GC/MS/MS).


U.S. Drought Monitor, January 17, 2017, Richard Tinker Jan 2017

U.S. Drought Monitor, January 17, 2017, Richard Tinker

United States Agricultural Commodities in Drought Archive

Drought map of U.S. for January 17, 2017 (1/17/17) plus: U.S. crop areas experiencing drought (map), Approximate percentage of crop located in drought, by state (bar graph), Percent of crop area located in drought, past 52 weeks (line graph) for: Corn, Soybeans, Hay, Cattle, Winter wheat.


U.S. Drought Monitor, January 10, 2017, David Miskus Jan 2017

U.S. Drought Monitor, January 10, 2017, David Miskus

United States Agricultural Commodities in Drought Archive

Drought map of U.S. for January 10, 2017 (1/10/17) plus: U.S. crop areas experiencing drought (map), Approximate percentage of crop located in drought, by state (bar graph), Percent of crop area located in drought, past 52 weeks (line graph) for: Corn, Soybeans, Hay, Cattle, Winter wheat.


U.S. Drought Monitor, January 3, 2017, David Miskus Jan 2017

U.S. Drought Monitor, January 3, 2017, David Miskus

United States Agricultural Commodities in Drought Archive

Drought map of U.S. for January 3, 2017 (1/3/17) plus: U.S. crop areas experiencing drought (map), Approximate percentage of crop located in drought, by state (bar graph), Percent of crop area located in drought, past 52 weeks (line graph) for: Corn, Soybeans, Hay, Cattle, Winter wheat.


Coral Bleaching And The Effect Of Disturbances On The Damselfish Community On Lizard Island, Australia, Alejandra Munoz Jan 2017

Coral Bleaching And The Effect Of Disturbances On The Damselfish Community On Lizard Island, Australia, Alejandra Munoz

Independent Study Project (ISP) Collection

Coral reefs are characterized by their dynamic ecological processes that supports a high diversity through the recruitment of marine species and temporal disturbances that can have positive effects on the system. In the face of global climate change however, coral reefs face intense coral bleaching and increased degradation as they may begin to have less time to recover between bleaching events in the near future. Little is known on the long term effects of coral bleaching and habitat degradation on reef fish communities and much less is known about the mechanisms that bring about changes to reef fish assemblages.

This …


A Spanner In The Works: Human–Elephant Conflict Complicates The Food–Water–Energy Nexus In Drylands Of Africa, Bruce Schulte, Mwangi Githiru, Urbanus Mutwiwa, Simon Kasaine Jan 2017

A Spanner In The Works: Human–Elephant Conflict Complicates The Food–Water–Energy Nexus In Drylands Of Africa, Bruce Schulte, Mwangi Githiru, Urbanus Mutwiwa, Simon Kasaine

Biology Faculty Publications

The two major conservation issues for drylands of Africa are habitat loss or degradation and habitat fragmentation, largely fromagriculture, charcoal production, and infrastructural development. A key question for management is how these landscapes can retain their critical ecological functions and services, while simultaneously supporting resilient livelihoods. It is a clear nexus question involving food (agriculture), water, and energy (fuelwood), which is complicated by human–wildlife conflicts. While these could appear disparate issues, they are closely connected in dryland forest landscapes of Africa where elephants occur close to areas of human habitation. For instance, crop failure, whether due to weather or wildlife …


Distribution, Diversity, And Den Locations Of Canidae And Hyaenidae Species Across Habitat Type At Enashiva Nature Refuge, Grace Bullington Jan 2017

Distribution, Diversity, And Den Locations Of Canidae And Hyaenidae Species Across Habitat Type At Enashiva Nature Refuge, Grace Bullington

Independent Study Project (ISP) Collection

Due to the importance of top-trophic level predators have on their environment including regulating prey species and influencing ecosystem biodiversity, it is important to monitor top-trophic level predators to understand how they shape their ecosystem. While top-trophic level predators can benefit the ecosystem, they can also cause problems for surrounding human settlements like predation on livestock. Species in the Canidae and Hyaenidae families occupy the top-trophic level and can influence their ecosystem and cause human-wildlife conflict.

This study looked at the distribution, diversity, and den locations of Canidae and Hyaenidae species at Enashiva Nature Refuge over the course of 21 …


Estimating The Number Of Recreational Anglers For A Given Waterbody, Kevin L. Pope, Larkin A. Powell, Brian S. Harmon, Mark A. Pegg, Christopher J. Chizinski Jan 2017

Estimating The Number Of Recreational Anglers For A Given Waterbody, Kevin L. Pope, Larkin A. Powell, Brian S. Harmon, Mark A. Pegg, Christopher J. Chizinski

Nebraska Cooperative Fish and Wildlife Research Unit: Staff Publications

Knowing how many anglers use a given body of water is paramount for understanding components of a fishery related to angling pressure and harvest, yet no study has attempted to provide an estimate of the population size of anglers for a given waterbody. Here, we use information from creel surveys in a removal-sampling framework to estimate total numbers of anglers using six reservoirs in Nebraska, USA, and we examine the influence of the duration of sampling period on those estimates. Population estimates (N ± SE) of unique anglers were 2050 ± 45 for Branched Oak Lake, 1992 ± 29 for …


A Descriptive Analysis Of Regal Fritillary (Speyeria Idalia) Habitat Utilizing Biological Monitoring Data Along The Big Bend Of The Platte River, Ne, Andrew J. Caven, Kelsey C. King, Joshua D. Wiese, Emma M. Brinley Buckley Jan 2017

A Descriptive Analysis Of Regal Fritillary (Speyeria Idalia) Habitat Utilizing Biological Monitoring Data Along The Big Bend Of The Platte River, Ne, Andrew J. Caven, Kelsey C. King, Joshua D. Wiese, Emma M. Brinley Buckley

Nebraska Cooperative Fish and Wildlife Research Unit: Staff Publications

Speyeria idalia populations have declined as much as 95 percent over the last three decades. Here we critically evaluate prairie habitat components along the Platte River in central Nebraska that S. idalia populations require in an effort to better inform conservation efforts. We utilized S. idalia count data from biological monitoring transects where vegetation, soils, land management, and flooding frequency data were also collected to describe the habitat constituents associated with S. idalia presence. We utilize comparative statistics, Pearson’s correlation analysis, and random forest analysis to model S. idalia habitat on land owned and managed by a small conservation NGO. …


Modeling With A Conceptual Representation: Is It Necessary? Does It Work?, Rebecca C. Jordan, Steven Gray, Amanda E. Sorensen, Samantha Pasewark, Suparna Sinha, Cindy E. Hmelo-Silver Jan 2017

Modeling With A Conceptual Representation: Is It Necessary? Does It Work?, Rebecca C. Jordan, Steven Gray, Amanda E. Sorensen, Samantha Pasewark, Suparna Sinha, Cindy E. Hmelo-Silver

Nebraska Cooperative Fish and Wildlife Research Unit: Staff Publications

In response to recent educational imperatives in the United States, modeling and systems thinking have been identified as being critical for science learning. In this paper, we investigate models in the classroom from two important perspectives: (1) from the teacher perspective to understand how teachers perceive models and use models in the classroom and (2) from the students perspective to understand how student use model-based reasoning to represent their understanding in a classroom setting. Qualitative data collected from 19 teachers who attended a professional development workshop in the northeastern United States indicate that while teachers see the value in teaching …


Severe Drought Impacts Female Pheasant Physiology In Southwest Nebraska, Jessica A. Laskowski, Gwendolyn C. Bachman, Joseph J. Fontaine Jan 2017

Severe Drought Impacts Female Pheasant Physiology In Southwest Nebraska, Jessica A. Laskowski, Gwendolyn C. Bachman, Joseph J. Fontaine

Nebraska Cooperative Fish and Wildlife Research Unit: Staff Publications

In 2012, Nebraska experienced one of the worst droughts since the 1930s, accompanied by abnormally high temperatures. We studied the impacts of the 2012 summer drought on female ring-necked pheasant (Phasianus colchicus) body condition and baseline and stress-induced corticosterone concentrations (CORT). We hypothesized that drought conditions would reduce pheasant body condition, increase chronic stress resulting in elevated baseline CORT levels, and down-regulate pheasant stress response to acute stressors, resulting in reduced stress-induced CORT concentrations. In southwestern Nebraska, we captured female pheasants in 2012 (pre-drought) and 2013 (post-drought). Pheasants had poorer body condition after the drought. Although female CORT …


Frobenius Betti Numbers And Modules Of Finite Protective Dimension, Alessandro De Stefani, Craig Huneke, Luis Nunez-Betancourt Jan 2017

Frobenius Betti Numbers And Modules Of Finite Protective Dimension, Alessandro De Stefani, Craig Huneke, Luis Nunez-Betancourt

Nebraska Cooperative Fish and Wildlife Research Unit: Staff Publications

Let (R,m,K) be a local ring, and let M be an R-module of finite length. We study asymptotic invariants, bfi (M,R), defined by twisting with Frobenius the free resolution of M. This family of invariants includes the Hilbert-Kunz multiplicity (eHK (m,R) = BF0 (K,R)). We discuss several properties of these numbers that resemble the behavior of the Hilbert-Kunz multiplicity. Furthermore, we study when the vanishing of BFI (M,R,) implies that M complete characterization of the vanishing of BFi (M,R0 for one-dimensional rings. As a consequence of our methods we give conditions for the non-existence of syzygies of finite length.


Balancing Stability And Flexibility In Adaptive Governance: An Analysis Of Tools Available In U.S. Environmental Law, Robin Kundis Craig, Ahjond S. Garmestani, Craig R. Allen, Craig Anthony (Tony) Arnold, Hannah E. Birge, Daniel A. Decaro, Alexander K. Fremier, Hannah Gosnell, Edella Schlager Jan 2017

Balancing Stability And Flexibility In Adaptive Governance: An Analysis Of Tools Available In U.S. Environmental Law, Robin Kundis Craig, Ahjond S. Garmestani, Craig R. Allen, Craig Anthony (Tony) Arnold, Hannah E. Birge, Daniel A. Decaro, Alexander K. Fremier, Hannah Gosnell, Edella Schlager

Nebraska Cooperative Fish and Wildlife Research Unit: Staff Publications

Adaptive governance must work “on the ground,” that is, it must operate through structures and procedures that the people it governs perceive to be legitimate and fair, as well as incorporating processes and substantive goals that are effective in allowing social-ecological systems (SESs) to adapt to climate change and other impacts. To address the continuing and accelerating alterations that climate change is bringing to SESs, adaptive governance generally will require more flexibility than prior governance institutions have often allowed. However, to function as good governance, adaptive governance must pay real attention to the problem of how to balance this increased …


Capturing Change: The Duality Of Time-Lapse Imagery To Acquire Data And Depict Ecological Dynamics, Emma Brinley Buckley, Craig R. Allen, Michael L. Forsberg, Michael Farrell, Andrew J. Caven Jan 2017

Capturing Change: The Duality Of Time-Lapse Imagery To Acquire Data And Depict Ecological Dynamics, Emma Brinley Buckley, Craig R. Allen, Michael L. Forsberg, Michael Farrell, Andrew J. Caven

Nebraska Cooperative Fish and Wildlife Research Unit: Staff Publications

We investigate the scientific and communicative value of time-lapse imagery by exploring applications for data collection and visualization. Time-lapse imagery has a myriad of possible applications to study and depict ecosystems and can operate at unique temporal and spatial scales to bridge the gap between large-scale satellite imagery projects and observational field research. Time-lapse data sequences, linking time-lapse imagery with data visualization, have the ability to make data come alive for a wider audience by connecting abstract numbers to images that root data in time and place. Utilizing imagery from the Platte Basin Timelapse Project, water inundation and vegetation phenology …


Adaptive Management Of Rangeland Systems, Craig R. Allen, David G. Angeler, Joseph J. Fontaine, Ahjond S. Garmestani, Noelle M. Chaine, Kevin L. Pope, Dirac L. Twidwell Jr. Jan 2017

Adaptive Management Of Rangeland Systems, Craig R. Allen, David G. Angeler, Joseph J. Fontaine, Ahjond S. Garmestani, Noelle M. Chaine, Kevin L. Pope, Dirac L. Twidwell Jr.

Nebraska Cooperative Fish and Wildlife Research Unit: Staff Publications

Adaptive management is an approach to natural resource management that uses structured learning to reduce uncertainties for the improvement of management over time. The origins of adaptive management are linked to ideas of resilience theory and complex systems. Rangeland management is particularly well suited for the application of adaptive management, having sufficient controllability and reducible uncertainties. Adaptive management applies the tools of structured decision making and requires monitoring, evaluation, and adjustment of management. Adaptive governance, involving sharing of power and knowledge among relevant stakeholders, is often required to address conflict situations. Natural resource laws and regulations can present a barrier …


Network Analysis Of A Regional Fishery: Implications For Management Of Natural Resources, And Recruitment And Retention Of Anglers, Dustin R. Martin, Daizaburo Shizuka, Christopher J. Chizinski, Kevin L. Pope Jan 2017

Network Analysis Of A Regional Fishery: Implications For Management Of Natural Resources, And Recruitment And Retention Of Anglers, Dustin R. Martin, Daizaburo Shizuka, Christopher J. Chizinski, Kevin L. Pope

Nebraska Cooperative Fish and Wildlife Research Unit: Staff Publications

Angler groups and water-body types interact to create a complex social-ecological system. Network analysis could inform detailed mechanistic models on, and provide managers better information about, basic patterns of fishing activity. Differences in behavior and reservoir selection among angler groups in a regional fishery, the Salt Valley fishery in southeastern Nebraska, USA, were assessed using a combination of cluster and network analyses. The four angler groups assessed ranged from less active, unskilled anglers (group One) to highly active, very skilled anglers (group Four). Reservoir use patterns and the resulting network communities of these four angler groups differed; the number of …


Shorebird Stopover Habitat Decisions In A Changing Landscape, Caitlyn Gillespie, Joseph J. Fontaine Jan 2017

Shorebird Stopover Habitat Decisions In A Changing Landscape, Caitlyn Gillespie, Joseph J. Fontaine

Nebraska Cooperative Fish and Wildlife Research Unit: Staff Publications

To examine how habitat use by sandpipers (Calidris spp.; Baird’s sandpipers, dunlin, least sandpipers, pectoral sandpipers, semipalmated sandpipers, stilt sandpipers, and white-rumped sandpipers) varies across a broad suite of environmental conditions, we conducted surveys at wetlands throughout the spring migratory period in 2013 and 2014 in 2 important stopover regions: the Rainwater Basin (RWB) in Nebraska, USA, and the Prairie Pothole Region (PPR) in South Dakota, USA. Because providing adequate energetic resources for migratory birds is a high priority for wetland management, we also measured invertebrate abundance at managed wetlands in the RWB to determine how food abundance influences …


Species Distributions Models In Wildlife Planning: Agricultural Policy And Wildlife Management In The Great Plains, Joseph J. Fontaine, Christopher F. Jorgensen, Erica F. Stuber, Lutz F. Gruber, Andrew A. Bishop, Jeffrey J. Lusk, Eric S. Zach, Karie L. Decker Jan 2017

Species Distributions Models In Wildlife Planning: Agricultural Policy And Wildlife Management In The Great Plains, Joseph J. Fontaine, Christopher F. Jorgensen, Erica F. Stuber, Lutz F. Gruber, Andrew A. Bishop, Jeffrey J. Lusk, Eric S. Zach, Karie L. Decker

Nebraska Cooperative Fish and Wildlife Research Unit: Staff Publications

We know economic and social policy has implications for ecosystems at large, but the consequences for a given geographic area or specific wildlife population are more difficult to conceptualize and communicate. Species distribution models, which extrapolate species-habitat relationships across ecological scales, are capable of predicting population changes in distribution and abundance in response to management and policy, and thus, are an ideal means for facilitating proactive management within a larger policy framework. To illustrate the capabilities of species distribution modeling in scenario planning for wildlife populations, we projected an existing distribution model for ring-necked pheasants (Phasianus colchicus) onto …


Protected Areas As Social-Ecological Systems: Perspectives From Resilience And Social-Ecological Systems Theory, Graeme S. Cumming, Craig R. Allen Jan 2017

Protected Areas As Social-Ecological Systems: Perspectives From Resilience And Social-Ecological Systems Theory, Graeme S. Cumming, Craig R. Allen

Nebraska Cooperative Fish and Wildlife Research Unit: Staff Publications

Conservation biology and applied ecology increasingly recognize that natural resource management is both an outcome and a driver of social, economic, and ecological dynamics. Protected areas offer a fundamental approach to conserving ecosystems, but they are also social-ecological systems whose ecological management and sustainability are heavily influenced by people. This editorial, and the papers in the invited feature that it introduces, discuss three emerging themes in social-ecological systems approaches to understanding protected areas: (1) the resilience and sustainability of protected areas, including analyses of their internal dynamics, their effectiveness, and the resilience of the landscapes within which they occur; (2) …


A Bayesian Method For Assessing Multi-Scale Species-Habitat Relationships, Erica F. Stuber, Lutz F. Gruber, Joseph J. Fontaine Jan 2017

A Bayesian Method For Assessing Multi-Scale Species-Habitat Relationships, Erica F. Stuber, Lutz F. Gruber, Joseph J. Fontaine

Nebraska Cooperative Fish and Wildlife Research Unit: Staff Publications

Context Scientists face several theoretical and methodological challenges in appropriately describing fundamental wildlife-habitat relationships in models. The spatial scales of habitat relationships are often unknown, and are expected to follow a multi-scale hierarchy. Typical frequentist or information theoretic approaches often suffer under collinearity in multiscale studies, fail to converge when models are complex or represent an intractable computational burden when candidate model sets are large.

Objectives Our objective was to implement an automated, Bayesian method for inference on the spatial scales of habitat variables that best predict animal abundance.

Methods We introduce Bayesian latent indicator scale selection (BLISS), a Bayesian …


Reframing Communication About Zika And Mosquitoes To Increase Disease Prevention Behavior, Amanda E. Sorensen, Rebecca C. Jordan, Shannon Ladeau Jan 2017

Reframing Communication About Zika And Mosquitoes To Increase Disease Prevention Behavior, Amanda E. Sorensen, Rebecca C. Jordan, Shannon Ladeau

Nebraska Cooperative Fish and Wildlife Research Unit: Staff Publications

Emergence of invasive vector species and the diseases they carry present a clear danger to the public as well as a challenge for scientists and experts to control effectively. Given the urgent need to address this phenomenon, we suggest that desired public action toward these invasive vectors can be motivated through intentional framing in science communication. In this paper, we sought to evaluate the effect of framing about ZIKV (Zika virus) on reported willingness to comply with mosquito prevention action. Post framing intervention, we found a significant increase (N = 26, p < 0.001) in individuals willing to take preventative action against mosquitoes. By methodically investigating best communication practices, this study and others can help practitioners mobilize communities to address large-scale ecological problems. Additionally, the principles outlined here may be transferrable to other communication efforts about ecological issues outside of ZIKV and mosquitoes.


Current Status And Long-Term Trends In Water Quality And Living Resources In The Virginia Tributaries And Chesapeake Bay Mainstem From 1985 Through 2015, Daniel M. Dauer, Todd A. Egerton, John R. Donat, Michael F. Lane, Suzanne C. Doughten, Cindy Johnson, Monika Arora Jan 2017

Current Status And Long-Term Trends In Water Quality And Living Resources In The Virginia Tributaries And Chesapeake Bay Mainstem From 1985 Through 2015, Daniel M. Dauer, Todd A. Egerton, John R. Donat, Michael F. Lane, Suzanne C. Doughten, Cindy Johnson, Monika Arora

Status and Trends for Virginia Chesapeake Bay

(First paragraph) The period prior to the implementation of the Chesapeake Bay Monitoring Program was characterized by a marked decline in the water quality of the Chesapeake Bay. The disappearance of submerged aquatic vegetation in certain regions of the Bay, declines in the abundance of some commercially and recreationally important species, increases in the incidence of low dissolved oxygen events, changes in the Bay's food web, and other ecological problems have been related to the deteriorating water quality (e.g. USEPA, 1982,1983;Officer et al.,1984; Orth and Moore, 1984). The results of concentrated research efforts in the late 1970s and early 1980s …


Assessing Responses Of Betula Papyrifera (Paper Birch) To Climate Variability In A Remnant Population Along The Niobrara River In Nebraska Through Dendroecological And Remote Sensing Techniques, Evan Bumann Jan 2017

Assessing Responses Of Betula Papyrifera (Paper Birch) To Climate Variability In A Remnant Population Along The Niobrara River In Nebraska Through Dendroecological And Remote Sensing Techniques, Evan Bumann

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

Remnant populations of the boreal species Betula papyrifera, found along north-facing canyons and river banks of the Niobrara River Valley in north-central Nebraska, represent one of the southernmost distributions of the species in North America. Although, the species has persisted in the Great Plains after the Wisconsin Glaciation due to the local topography and microclimatic conditions, canopy dieback has been reported in recent years, which is believed to be attributed to temperature change. Therefore, the goals of this research are to: 1) use dendroecological techniques, or the study of tree rings to assess the responses B. papyrifera to intra- and …


Effects Of Post Eviction Resettlement On Land-Use And Cover Change In Uganda’S Oil Exploration Areas, Joseph Ssekandi, John Mburu, Oliver Wasonga, Laban Macopiyo, Charles A. Francis Jan 2017

Effects Of Post Eviction Resettlement On Land-Use And Cover Change In Uganda’S Oil Exploration Areas, Joseph Ssekandi, John Mburu, Oliver Wasonga, Laban Macopiyo, Charles A. Francis

Department of Agronomy and Horticulture: Faculty Publications

Evaluation of the changes in land use and land cover change (LULCC) in respect to oil exploration across the Albertine region in Uganda has been focused around the exploration areas and protected areas, with no attention to the potential impacts of evictees’ activities on resettled areas. This study used LANDSAT images to analyze the land use and land cover changes (LULCC) among the period before eviction (2002 and 2005) at the climax of eviction and resettlements (2005-2011), and during the post-resettlement period (2011-2015) to quantify the impacts of resettlements on the environment. LANDSAT images were processed using ERDAS IMAGINE software …


Effects Of Grazers And Elevated Temperature On The Dynamics Of A Wastewater Algal Treatment System, Mengyuan Li Jan 2017

Effects Of Grazers And Elevated Temperature On The Dynamics Of A Wastewater Algal Treatment System, Mengyuan Li

Theses and Dissertations

Wastewater algal treatment systems (ATS) have been shown to effectively remove excessive nutrients from wastewater and prevent eutrophication. However, the performance of ATS could be strongly affected by environmental factors. This study examined (1) the effect of grazers on nutrient removal rates and (2) the effect of 1.7 °C increase in temperature on algal biomass. The effect of grazers was assessed outdoors by analyzing dissolved and tissue nutrient concentrations in ATS with and without biological pesticide in two 20-day trials. The effect of elevated temperature was evaluated indoors by comparing algal biomass between heated and non-heated ATS for 20 days. …