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2017

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Articles 271 - 300 of 428

Full-Text Articles in Natural Resources and Conservation

The Giving Trees: The (Un)Sustainability Of Palm Oil In Indonesia, Amber Rosche Mar 2017

The Giving Trees: The (Un)Sustainability Of Palm Oil In Indonesia, Amber Rosche

Seaver College Research And Scholarly Achievement Symposium

Palm oil is the main source of cooking oil for much of Africa, Asia and Brazil. Due to the increasingly high demand for palm oil, countries such as Indonesia and Malaysia have cleared millions of acres of tropical rainforests to create space for oil palm plantations. This deforestation has led to extreme environmental and social concerns such as the burning of peatlands, the endangerment of a number of species, including the Sumatran Tiger, rhinos and orangutans, and the displacement of native populations. Indonesia is the world’s largest consumer and producer of palm oil, producing almost half of the world’s supply …


Feasibility Analysis Of Using Inverse Modeling For Estimating Field-Scale Evapotranspiration In Maize And Soybean Fields From Soil Water Content Monitoring Networks, Foad Foolad, Trenton E. Franz, Teijun Wang, Justin Gibson, Ayse Kilie, Richard Allen, Andrew E. Suyker Mar 2017

Feasibility Analysis Of Using Inverse Modeling For Estimating Field-Scale Evapotranspiration In Maize And Soybean Fields From Soil Water Content Monitoring Networks, Foad Foolad, Trenton E. Franz, Teijun Wang, Justin Gibson, Ayse Kilie, Richard Allen, Andrew E. Suyker

School of Natural Resources: Faculty Publications

In this study, the feasibility of using inverse vadose zone modeling for estimating field-scale actual evapotranspiration (ETa/ was explored at a long-term agricultural monitoring site in eastern Nebraska. Data from both point-scale soil water content (SWC) sensors and the areaaverage technique of cosmic-ray neutron probes were evaluated against independent ETa estimates from a co-located eddy covariance tower. While this methodology has been successfully used for estimates of groundwater recharge, it was essential to assess the performance of other components of the water balance such as ETa. In light of recent evaluations of land surface models (LSMs), independent estimates of hydrologic …


Land Conservation In A Changing Climate:Stewardship Science And Financing, Bradford S. Gentry, Shelley Clark, Colin Kelly, Joshua Morse Mar 2017

Land Conservation In A Changing Climate:Stewardship Science And Financing, Bradford S. Gentry, Shelley Clark, Colin Kelly, Joshua Morse

Yale School of the Environment Publications Series

Report of the 2016 Berkley Workshop

Held at the Pocantico Center of the Rockefeller Brothers Fund, Tarrytown, NY - July 2016


Estimating Seasonal Variation In Condition Of Yellow Perch, Emily Anne Powers Mar 2017

Estimating Seasonal Variation In Condition Of Yellow Perch, Emily Anne Powers

Biology Graduate Theses

Research has shown that Yellow Perch Perca flavescens, found throughout lakes and streams of North America, are good indicators of environmental health. Due to the correlation between fish condition and ecosystem health it is essential to reliably estimate condition to better manage our fisheries. Therefore, the study objectives were to measure the seasonal changes in adult Yellow Perch percent dry weight (PDW), and compare the reliability of bioelectrical impedance analysis (BIA) and morphometric-based estimates of condition. The seasonal fluctuations in average monthly PDW were measured over a two- year period and were sinusoidal in shape with peaks in August 2015 …


Geoengineering, Marine Microalgae, And Climate Stabilization In The 21st Century, Charles H. Greene, Mark E. Huntley, Ian Archibald, Léda N. Gerber, Deborah L. Sills, Joe Granados, Colin M. Beal, Michael J. Walsh Mar 2017

Geoengineering, Marine Microalgae, And Climate Stabilization In The 21st Century, Charles H. Greene, Mark E. Huntley, Ian Archibald, Léda N. Gerber, Deborah L. Sills, Joe Granados, Colin M. Beal, Michael J. Walsh

Natural & Applied Sciences Faculty Publications

Society has set ambitious targets for stabilizing mean global temperature. To attain these targets, it will have to reduce CO2 emissions to near zero by mid-century and subsequently remove CO2 from the atmosphere during the latter half of the century. There is a recognized need to develop technologies for CO2 removal; however, attempts to develop direct air-capture systems have faced both energetic and financial constraints. Recently, BioEnergy with Carbon Capture and Storage (BECCS) has emerged as a leading candidate for removing CO2 from the atmosphere. However, BECCS can have negative consequences on land, nutrient, and water use as well as …


Death And Destruction: Insight Into The Rhino Poaching Epidemic In South Africa, Richard Wayne Charlton Feb 2017

Death And Destruction: Insight Into The Rhino Poaching Epidemic In South Africa, Richard Wayne Charlton

Theses and Dissertations

The poaching of wildlife has been a concern to many involved in the protection of wildlife. Poaching is found throughout the world and has been around for thousands of years. In the past century, poaching has reached new heights and the concern of an extinction of a species has bought the topic of poaching to new light. Whilst poaching has been seen as a biological or conservation topic in the past, criminologists around the world have now started to delve into the topic. The poaching of wildlife and more so in recent years, rhino poaching, has been a concern in …


Legacies Of Stream Channel Modification Revealed Using General Land Office Surveys, With Implications For Water Temperature And Aquatic Life, Seth M. White, Casey Justice, Denise A. Kelsey, Dale A. Mccullough, Tyanna Smith Feb 2017

Legacies Of Stream Channel Modification Revealed Using General Land Office Surveys, With Implications For Water Temperature And Aquatic Life, Seth M. White, Casey Justice, Denise A. Kelsey, Dale A. Mccullough, Tyanna Smith

Environmental Science and Management Faculty Publications and Presentations

Land use legacies can have a discernible influence in present-day watersheds and should be accounted for when designing conservation strategies for riverine aquatic life. We describe the environmental history of three watersheds within the Grande Ronde subbasin of the Columbia River using General Land Office survey field notes from the 19th century. In the two watersheds severely impacted by Euro-American land use, stream channel widths—a metric representing habitat simplification—increased from an average historical width of 16.8 m to an average present width of 20.8 m in large streams; 4.3 m to 5.5 m in small, confined or partly confined streams; …


Incorporating Sociocultural Phenomena Into Ecosystem-Service Valuation: The Importance Of Critical Pluralism, Carena J. Van Riper, Adam C. Landon, Sarah Kidd, Patrick Bitterman, Lee A. Fitzgerald, Elise F. Granek, Sonia Ibarra, David Iwaniec, Christopher Raymond, David Toledo Feb 2017

Incorporating Sociocultural Phenomena Into Ecosystem-Service Valuation: The Importance Of Critical Pluralism, Carena J. Van Riper, Adam C. Landon, Sarah Kidd, Patrick Bitterman, Lee A. Fitzgerald, Elise F. Granek, Sonia Ibarra, David Iwaniec, Christopher Raymond, David Toledo

Environmental Science and Management Faculty Publications and Presentations

Ecosystem-services scholarship has largely focused on monetary valuation and the material contributions of ecosystems to human well-being. Increasingly, research is calling for a deeper understanding of how less tangible, nonmaterial values shape management and stakeholder decisions. We propose a framework that characterizes a suite of sociocultural phenomena rooted in key social science disciplines that are currently underrepresented in the ecosystem-services literature. The results from three example studies are presented to demonstrate how the tenets of this conceptual model can be applied in practice. We consider the findings from these studies in light of three priorities for future research: (1) complexities …


Roosevelt, Naturally, Duane G. Jundt Jan 2017

Roosevelt, Naturally, Duane G. Jundt

Northwestern Review

This essay examines the outpouring of works on Theodore Roosevelt the conservationist and hunter since the publication of Douglas Brinkley’s The Wilderness Warrior in 2009. It provides brief reviews of several books, including children’s books, and an episode of a television documentary series. It also looks at two museum exhibitions and a play that deal with Roosevelt and conservation. The essay emphasizes the centrality that many of the works give to the connection between Roosevelt’s environmental ethos and his hunting. Under review are Douglas Brinkley, The Wilderness Warrior: Theodore Roosevelt and the Crusade for America; R.L. Wilson, Theodore Roosevelt: …


Effects Of Initial Aquifer Conditions On Economic Benefits From Groundwater Conservation, T. Foster, N. Brozovic, A. P. Butler Jan 2017

Effects Of Initial Aquifer Conditions On Economic Benefits From Groundwater Conservation, T. Foster, N. Brozovic, A. P. Butler

Daugherty Water for Food Global Institute: Faculty Publications

Worldwide, there is growing recognition of the need to reduce agricultural groundwater use in response to rapid rates of aquifer depletion. To date, however, few studies have evaluated how benefits of conservation vary along an aquifer’s depletion pathway. To address this question, we develop an integrated modeling framework that couples an agro-economic model of farmers’ field-level irrigation decisionmaking with a borehole-scale groundwater flow model. Unique to this framework is the explicit consideration of the dynamic reductions in well yields that occur as an aquifer is depleted, and how these changes in intraseasonal groundwater supply affect farmers’ ability to manage production …


A Six Thousand-Year Record Of Climate And Land-Use Change From Mediterranean Seagrass Mats, Lourdes Lopez-Merino, Nieves Colas-Ruiz, Maria Adame, Oscar Serrano, Antonio Cortizas, Miguel-Angel Mateo Jan 2017

A Six Thousand-Year Record Of Climate And Land-Use Change From Mediterranean Seagrass Mats, Lourdes Lopez-Merino, Nieves Colas-Ruiz, Maria Adame, Oscar Serrano, Antonio Cortizas, Miguel-Angel Mateo

Research outputs 2014 to 2021

The Mediterranean seagrass Posidonia oceanica maintains a biodiverse ecosystem and it is a world-wide important carbon sink. It grows for millennia, accumulating organic-rich soils (mats) beneath the meadows. This marine habitat is protected by the European Union; however, it is declining rapidly due to coastal development. Understanding its response to disturbances could inform habitat restoration, but many environmental impacts predate monitoring programs (years).
This research explores the palaeoecological potential of Posidonia mats to reconstruct six thousand years of environmental change that could have affected Posidonia meadows and, in turn, left an imprint on the mats.
Palynological, microcharcoal, magnetic susceptibility and …


Factors Affecting Snowy Plover Chick Survival In A Managed Population, Stephen J. Dinsmore, Eleanor P. Gaines, Scott F. Pearson, David J. Lauten, Kathleen J. Castelein Jan 2017

Factors Affecting Snowy Plover Chick Survival In A Managed Population, Stephen J. Dinsmore, Eleanor P. Gaines, Scott F. Pearson, David J. Lauten, Kathleen J. Castelein

Institute for Natural Resources Publications

Understanding survival of precocial chicks in the period immediately following hatching has important conservation implications because population growth is often sensitive to post-hatching survival. We studied federally threatened Western Snowy Plover (Charadrius nivosus nivosus) broods at the northern limit of their range in coastal Oregon (n ¼ 1,157) and Washington (n ¼ 84) from 1991 to 2011 in an attempt to understand seasonal, annual, and spatial patterns of chick survival. In Oregon, plover chick survival increased with age, varied between sites, and was greater at sites with predator management. The mean probability of surviving from hatch to fledging at 28 …


The Irreversible Momentum Of Clean Energy, Barack Obama Jan 2017

The Irreversible Momentum Of Clean Energy, Barack Obama

United States Department of Energy: Publications

The release of carbon dioxide (CO2) and other greenhouse gases (GHGs) due to human activity is increasing global average surface air temperatures, disrupting weather patterns, and acidifying the ocean. Left unchecked, the continued growth of GHG emissions could cause global average temperatures to increase by another 4°C or more by 2100 and by 1.5 to 2 times as much in many midcontinent and far northern locations. Although our understanding of the impacts of climate change is increasingly and disturbingly clear, there is still debate about the proper course for U.S. policy—a debate that is very much on display …


Long-Term Analysis Of The Asynchronicity Between Temperature And Precipitation Maxima In The United States Great Plains, Paul Flanagan, Jeffrey B. Basara, Xiangming Xiao Jan 2017

Long-Term Analysis Of The Asynchronicity Between Temperature And Precipitation Maxima In The United States Great Plains, Paul Flanagan, Jeffrey B. Basara, Xiangming Xiao

School of Natural Resources: Faculty Publications

Agriculture is a critical industry to the economy of the Great Plains (GP) region of North America and sensitive to change in weather and climate. Thus, improved knowledge of meteorological and climatological conditions during the growing season and associated variability across spatial and temporal scales is important. A distinct climate feature in the GP is the asynchronicity (AS) between the timing of temperature and precipitation maxima. This study investigated a long-term observational data set to quantify the AS and to address the impacts of climate variability and change. Global Historical Climate Network Daily (GHCN-Daily) data were utilized for this study; …


Enhancing Dynamical Seasonal Predictions Through Objective Regionalization, Saleh Satti, Benjamin F. Zaitchik, Hamaba S. Babr, Tsegaye Tadesse Jan 2017

Enhancing Dynamical Seasonal Predictions Through Objective Regionalization, Saleh Satti, Benjamin F. Zaitchik, Hamaba S. Babr, Tsegaye Tadesse

School of Natural Resources: Faculty Publications

Improving seasonal forecasts in East Africa has great implications for food security and water resources planning in the region. Dynamically based seasonal forecast systems have much to contribute to this effort, as they have demonstrated ability to represent and, to some extent, predict large-scale atmospheric dynamics that drive interannual rainfall variability in East Africa. However, these global models often exhibit spatial biases in their placement of rainfall and rainfall anomalies within the region, which limits their direct applicability to forecast-based decision-making. This paper introduces a method that uses objective climate regionalization to improve the utility of dynamically based forecast-system predictions …


Complex Variation In Habitat Selection Strategies Among Individuals Driven By Extrinsic Factors, Edward J. Raynor, Hawthorne L. Beyer, John M. Briggs, Anthony Joern Jan 2017

Complex Variation In Habitat Selection Strategies Among Individuals Driven By Extrinsic Factors, Edward J. Raynor, Hawthorne L. Beyer, John M. Briggs, Anthony Joern

School of Natural Resources: Faculty Publications

Understanding behavioral strategies employed by animals to maximize fitness in the face of environmental heterogeneity, variability, and uncertainty is a central aim of animal ecology. Flexibility in behavior may be key to how animals respond to climate and environmental change. Using a mechanistic modeling framework for simultaneously quantifying the effects of habitat preference and intrinsic movement on space use at the landscape scale, we investigate how movement and habitat selection vary among individuals and years in response to forage quality–quantity tradeoffs, environmental conditions, and variable annual climate. We evaluated the association of dynamic, biotic forage resources and static, abiotic landscape …


Carbon Flux Phenology From The Sky: Evaluation For Maize And Soybean, Alexandria G. Mccombs, Cuizhen Wang, Ankur Desai, Andrew E. Suyker, Sebastien C. Bird Jan 2017

Carbon Flux Phenology From The Sky: Evaluation For Maize And Soybean, Alexandria G. Mccombs, Cuizhen Wang, Ankur Desai, Andrew E. Suyker, Sebastien C. Bird

School of Natural Resources: Faculty Publications

Carbon flux phenology is widely used to understand carbon flux dynamics and surface exchange processes. Vegetation phenology has been widely evaluated by remote sensors; however, very few studies have evaluated the use of vegetation phenology for identifying carbon flux phenology. Currently available techniques to derive net ecosystem exchange (NEE) from a satellite image use a single generic modeling subgroup for agricultural crops. But, carbon flux phenological processes vary highly with crop types and land management practices; this paper reexamines this assumption. Presented here are an evaluation of ground-truth remotely sensed vegetation indices with in situ NEE measurements and an identification …


The Roles Of Ecology, Behavior And Effective Population Size In The Evolution Of A Community., C.M. Hung, S. Drovetski, R. M. Zink Jan 2017

The Roles Of Ecology, Behavior And Effective Population Size In The Evolution Of A Community., C.M. Hung, S. Drovetski, R. M. Zink

School of Natural Resources: Faculty Publications

No abstract provided.


Acoustic Characteristics Of Lekking Male Greater Prairie-Chicken (Tympanuchus Cupido Pinnatus) Vocalizations (Supplement), Cara E. Whalen, Mary Bomberger Brown, Joann Mcgee, Larkin A. Powell, Edward J. Walsh Jan 2017

Acoustic Characteristics Of Lekking Male Greater Prairie-Chicken (Tympanuchus Cupido Pinnatus) Vocalizations (Supplement), Cara E. Whalen, Mary Bomberger Brown, Joann Mcgee, Larkin A. Powell, Edward J. Walsh

School of Natural Resources: Faculty Publications

Boom

Cackle

Whine

Whoop


Reproductive Ecology Of Interior Least Tern And Piping Plover In Relation To Platte River Hydrology And Sandbar Dynamics, Jason M. Farnsworth, David M. Baasch, Chadwin B. Smith, Kevin L. Werbylo Jan 2017

Reproductive Ecology Of Interior Least Tern And Piping Plover In Relation To Platte River Hydrology And Sandbar Dynamics, Jason M. Farnsworth, David M. Baasch, Chadwin B. Smith, Kevin L. Werbylo

School of Natural Resources: Faculty Publications

Investigations of breeding ecology of interior least tern (Sternula antillarum athalassos) and piping plover (Charadrius melodus) in the Platte River basin in Nebraska, USA, have embraced the idea that these species are physiologically adapted to begin nesting concurrent with the cessation of spring floods. Low use and productivity on contemporary Platte River sandbars have been attributed to anthropomorphically driven changes in basin hydrology and channel morphology or to unusually late annual runoff events. We examined distributions of least tern and piping plover nest initiation dates in relation to the hydrology of the historical central Platte River …


Temporal Migration Shifts In The Aransas-Wood Buffalo Population Of Whooping Cranes (Grus Americana) Across North America, Joel G. Jorgensen, Mary Bomberger Brown Jan 2017

Temporal Migration Shifts In The Aransas-Wood Buffalo Population Of Whooping Cranes (Grus Americana) Across North America, Joel G. Jorgensen, Mary Bomberger Brown

School of Natural Resources: Faculty Publications

Birds are altering the phenology of critical life history events, including migration, in response to the effects of global climate change. Whooping Cranes (Grus americana) are one of the most critically endangered birds in the world. Their remnant population, referred to as the Aransas-Wood Buffalo Population, numbers between 300-400 individuals and migrates between the U.S. Gulf of Mexico coast and north-central Canada twice each year. Previous analyses suggested Whooping Crane migration was temporally constant in spring and fall. New analyses of observations spanning 1942-2016 show Whooping Crane migration is now occurring earlier in spring by approximately 22 days …


Drivers Of Nitrogen Transfer In Stream Food Webs Across Continents, B. C. Norman, M. R. Whiles, S. M. Collins, A. S. Flecker, S. K. Hamilton, S. L. Johnson, E. J. Rosi-Marshall, L. R. Ashkenas, W. B. Bowden, C. L. Crenshaw, T. Crowl, W. K. Dodds, R. O. Hall, R. El-Sabaawi, N. A. Griffiths, E. Marti, W. H. Mcdowell, S. D. Peterson, H. M. Rantala, T. Riis, K. S. Simon, J. L. Tank, S. A. Thomas, D. Von Schiller, J. R. Webster Jan 2017

Drivers Of Nitrogen Transfer In Stream Food Webs Across Continents, B. C. Norman, M. R. Whiles, S. M. Collins, A. S. Flecker, S. K. Hamilton, S. L. Johnson, E. J. Rosi-Marshall, L. R. Ashkenas, W. B. Bowden, C. L. Crenshaw, T. Crowl, W. K. Dodds, R. O. Hall, R. El-Sabaawi, N. A. Griffiths, E. Marti, W. H. Mcdowell, S. D. Peterson, H. M. Rantala, T. Riis, K. S. Simon, J. L. Tank, S. A. Thomas, D. Von Schiller, J. R. Webster

School of Natural Resources: Faculty Publications

Studies of trophic-level material and energy transfers are central to ecology. The use of isotopic tracers has now made it possible to measure trophic transfer efficiencies of important nutrients and to better understand how these materials move through food webs. We analyzed data from thirteen 15N-ammonium tracer addition experiments to quantify N transfer from basal resources to animals in headwater streams with varying physical, chemical, and biological features. N transfer efficiencies from primary uptake compartments (PUCs; heterotrophic microorganisms and primary producers) to primary consumers was lower (mean: 11.5%, range:100%). Total N transferred (as a rate) was greater in streams …


Partitioning Assimilatory Nitrogen Uptake In Streams: An Analysis Of Stable Isotope Tracer Additions Across Continents, J. L. Tank, E. Martí, T. Riis, D. Von Schiller, A. J. Reisinger, W. K. Dodds, M. R. Whiles, L. R. Ashkenas, W. B. Bowden, S. M. Collins, C. L. Crenshaw, T. A. Crowl, N. A. Griffiths, N. B. Grimm, S. K. Hamilton, S. L. Johnson, W. H. Mcdowell, B. M. Norman, E. J. Rosi, K. S. Simon, S. A. Thomas, J. R. Webster Jan 2017

Partitioning Assimilatory Nitrogen Uptake In Streams: An Analysis Of Stable Isotope Tracer Additions Across Continents, J. L. Tank, E. Martí, T. Riis, D. Von Schiller, A. J. Reisinger, W. K. Dodds, M. R. Whiles, L. R. Ashkenas, W. B. Bowden, S. M. Collins, C. L. Crenshaw, T. A. Crowl, N. A. Griffiths, N. B. Grimm, S. K. Hamilton, S. L. Johnson, W. H. Mcdowell, B. M. Norman, E. J. Rosi, K. S. Simon, S. A. Thomas, J. R. Webster

School of Natural Resources: Faculty Publications

Headwater streams remove, transform, and store inorganic nitrogen (N) delivered from surrounding watersheds, but excessive N inputs from human activity can saturate removal capacity. Most research has focused on quantifying N removal from the water column over short periods and in individual reaches, and these ecosystem-scale measurements suggest that assimilatory N uptake accounts for most N removal. However, cross-system comparisons addressing the relative role of particular biota responsible for incorporating inorganic N into biomass are lacking. Here we assess the importance of different primary uptake compartments on reach-scale ammonium (NH4+-N) uptake and storage across a wide range …


Tolerance: The Forgotten Child Of Plant Resistance, Robert K. D. Peterson, Andrea C. Varella, Leon G. Higley Jan 2017

Tolerance: The Forgotten Child Of Plant Resistance, Robert K. D. Peterson, Andrea C. Varella, Leon G. Higley

School of Natural Resources: Faculty Publications

Plant resistance against insect herbivory has greatly focused on antibiosis, whereby the plant has a deleterious effect on the herbivore, and antixenosis, whereby the plant is able to direct the herbivore away from it. Although these two types of resistance may reduce injury and yield loss, they can produce selection pressures on insect herbivores that lead to pest resistance. Tolerance, on the other hand, is a more sustainable pest management strategy because it involves only a plant response and therefore does not cause evolution of resistance in target pest populations. Despite its attractive attributes, tolerance has been poorly studied and …


Review Of Great Plains Geology By Robert F. Diffendal, Jon Trevelyan Jan 2017

Review Of Great Plains Geology By Robert F. Diffendal, Jon Trevelyan

School of Natural Resources: Faculty Publications

Professor Robert Diffendal Jr's little guidebook to the Great Plains of the USA makes for a fascinating read for an Englishman like me, who has never been there (but wants to). As he says in the article opposite, they rarely correspond to the impression most people have of them. For example, they are not just flat plains with cowboys herding longhorn cattle as you might imagine from the movies (in fact, they probably rarely were). Rather, it is clear from the guide that they can provide a visitor with an interesting mixture of geology, palaeontology, ecotourism and archaeology. In addition, …


Parallel Seasonal Patterns Of Photosynthesis, Fluorescence, And Reflectance Indices In Boreal Trees, Kyle R. Springer, Ran Wang, John A. Gamon Jan 2017

Parallel Seasonal Patterns Of Photosynthesis, Fluorescence, And Reflectance Indices In Boreal Trees, Kyle R. Springer, Ran Wang, John A. Gamon

School of Natural Resources: Faculty Publications

Tree species in the boreal forest cycle between periods of active growth and dormancy alter their photosynthetic processes in response to changing environmental conditions. For deciduous species, these changes are readily visible, while evergreen species have subtler foliar changes during seasonal transitions. In this study, we used remotely sensed optical indices to observe seasonal changes in photosynthetic activity, or photosynthetic phenology, of six boreal tree species. We evaluated the normalized difference vegetation index (NDVI), the photochemical reflectance index (PRI), the chlorophyll/carotenoid index (CCI), and steady-state chlorophyll fluorescence (FS) as a measure of solar-induced fluorescence (SIF), and compared these …


Parallel Seasonal Patterns Of Photosynthesis, Fluorescence, And Reflectance Indices In Boreal Trees, Kyle R. Springer, Ran Wang, John A. Gamon Jan 2017

Parallel Seasonal Patterns Of Photosynthesis, Fluorescence, And Reflectance Indices In Boreal Trees, Kyle R. Springer, Ran Wang, John A. Gamon

School of Natural Resources: Faculty Publications

Tree species in the boreal forest cycle between periods of active growth and dormancy alter their photosynthetic processes in response to changing environmental conditions. For deciduous species, these changes are readily visible, while evergreen species have subtler foliar changes during seasonal transitions. In this study, we used remotely sensed optical indices to observe seasonal changes in photosynthetic activity, or photosynthetic phenology, of six boreal tree species. We evaluated the normalized difference vegetation index (NDVI), the photochemical reflectance index (PRI), the chlorophyll/carotenoid index (CCI), and steady-state chlorophyll fluorescence (FS) as a measure of solar-induced fluorescence (SIF), and compared these …


Potential Of Windbreak Trees To Reduce Carbon Emissions By Agricultural Operations In The Us, William Ballesteros Possu, James R. Brandle, Michele Schoeneberger Jan 2017

Potential Of Windbreak Trees To Reduce Carbon Emissions By Agricultural Operations In The Us, William Ballesteros Possu, James R. Brandle, Michele Schoeneberger

School of Natural Resources: Faculty Publications

Along with sequestering C in forest, trees on farms are able to contribute to greenhouse mitigation through emission avoidance mechanisms. To evaluate the magnitude of these contributions, emission avoidance contributions for field and farmstead windbreak designs in regions across the United States were estimated, along with greenhouse gas (GHG) emission budgets for corn, soybean, winter wheat, and potato operations. We looked at farming scenarios with large (600 ha), mid (300 ha), and small-size (60 ha) farms containing farmsteads built before and after 2000, and growing different cropping systems. Windbreak scenarios were assumed to be up to 5% of the crop …


Common Carp Disrupt Ecosystem Structure And Function Through Middle-Out Effects, Mark A. Kaemingk, Jeffrey C. Jolley, Craig P. Paukert, David W. Willis, Kjetil Henderson, Richard S. Holland, Greg A. Wanner, Mark L. Lindvall Jan 2017

Common Carp Disrupt Ecosystem Structure And Function Through Middle-Out Effects, Mark A. Kaemingk, Jeffrey C. Jolley, Craig P. Paukert, David W. Willis, Kjetil Henderson, Richard S. Holland, Greg A. Wanner, Mark L. Lindvall

School of Natural Resources: Faculty Publications

Middle-out effects or a combination of top-down and bottom-up processes create many theoretical and empirical challenges in the realm of trophic ecology. We propose using specific autecology or species trait (i.e. behavioural) information to help explain and understand trophic dynamics that may involve complicated and nonunidirectional trophic interactions. The common carp (Cyprinus carpio) served as our model species for whole-lake observational and experimental studies; four trophic levels were measured to assess common carp-mediated middle-out effects across multiple lakes. We hypothesised that common carp could influence aquatic ecosystems through multiple pathways (i.e. abiotic and biotic foraging, early life feeding, nutrient). Both …


How Do Undergraduate Stem Mentors Reflect Upon Their Mentoring Experiences In An Outreach Program Engaging K-8 Youth?, Kari Nelson, Jaime Sabel, Cory Forbes, Neal Grandgenett, William Tapprich, Christine E. Cutucache Jan 2017

How Do Undergraduate Stem Mentors Reflect Upon Their Mentoring Experiences In An Outreach Program Engaging K-8 Youth?, Kari Nelson, Jaime Sabel, Cory Forbes, Neal Grandgenett, William Tapprich, Christine E. Cutucache

School of Natural Resources: Faculty Publications

Background: Many university students are becoming involved in mentoring programs, yet few studies describe the impact of mentoring on the mentor. Additionally, many studies report that students graduating from college are not prepared to enter the workforce in terms of key career skills and/or content knowledge. Herein, we examine the impact of our program, NE STEM 4U (Nebraska Science, Technology, Engineering and Math for You), in which undergraduate (UG) mentors engage K-8 youth in after-school STEM experiments. The UGs reflected upon their experiences using post-mentoring evaluations, 12- and 24-week interviews, and exit surveys. Many of the questions asked of the …