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School of Natural Resources: Faculty Publications

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Full-Text Articles in Other Environmental Sciences

Fostering Student Sense Making In Elementary Science Learning Environments: Elementary Teachers’ Use Of Science Curriculum Materials To Promote Explanation Construction, Laura Zangori, Cory Forbes, Mandy Biggers Jan 2013

Fostering Student Sense Making In Elementary Science Learning Environments: Elementary Teachers’ Use Of Science Curriculum Materials To Promote Explanation Construction, Laura Zangori, Cory Forbes, Mandy Biggers

School of Natural Resources: Faculty Publications

While research has shown that elementary (K-5) students are capable of engaging in the scientific practice of explanation construction, commonly-used elementary science curriculum materials may not always afford them opportunities to do so. As a result, elementary teachers must often adapt their science curriculum materials to better support students’ explanation construction and foster student sense making. However, little research has been conducted to explore if and, if so, how and why, elementary teachers modify science curriculum materials to engage students in explanation construction. We use an embedded mixed methods research design to explore elementary teachers’ (n = 45) curricular adaptations …


The Under-Ice Microbiome Of Seasonally Frozen Lakes, Stefan Bertilsson, Amy Burgin, Cayelan C. Carey, Samuel B. Fey, Hans-Peter Grossart, Lorena M. Grubisic, Ian D. Jones, Georgiy Kirillin, Jay T. Lennon, Ashley Shade, Robyn L. Smyth Jan 2013

The Under-Ice Microbiome Of Seasonally Frozen Lakes, Stefan Bertilsson, Amy Burgin, Cayelan C. Carey, Samuel B. Fey, Hans-Peter Grossart, Lorena M. Grubisic, Ian D. Jones, Georgiy Kirillin, Jay T. Lennon, Ashley Shade, Robyn L. Smyth

School of Natural Resources: Faculty Publications

Compared to the well-studied open water of the ‘‘growing’’ season, under-ice conditions in lakes are characterized by low and rather constant temperature, slow water movements, limited light availability, and reduced exchange with the surrounding landscape. These conditions interact with ice-cover duration to shape microbial processes in temperate lakes and ultimately influence the phenology of community and ecosystem processes. We review the current knowledge on microorganisms in seasonally frozen lakes. Specifically, we highlight how under-ice conditions alter lake physics and the ways that this can affect the distribution and metabolism of auto- and heterotrophic microorganisms. We identify functional traits that we …


Students Understanding Of Cells And Heredity: Patterns Of Understanding In The Context Of A Curriculum Implementation In Fifth And Seventh Grades, Dante Cisterna, Michelle Williams, Joi Merritt Jan 2013

Students Understanding Of Cells And Heredity: Patterns Of Understanding In The Context Of A Curriculum Implementation In Fifth And Seventh Grades, Dante Cisterna, Michelle Williams, Joi Merritt

School of Natural Resources: Faculty Publications

No abstract provided.


Recent Updates Of The Calibration-Free Evapotranspiration Mapping (Cremap) Method, Jozsef Szilagyi Jan 2013

Recent Updates Of The Calibration-Free Evapotranspiration Mapping (Cremap) Method, Jozsef Szilagyi

School of Natural Resources: Faculty Publications

No abstract provided.


Modeling The Production Of Multiple Ecosystem Services From Agricultural And Forest Landscapes In Rhode Island, Tingting Liu, Nathaniel H. Merrill, Arthur J. Gold, Dorothy Q. Kellogg, Emi Uchida Jan 2013

Modeling The Production Of Multiple Ecosystem Services From Agricultural And Forest Landscapes In Rhode Island, Tingting Liu, Nathaniel H. Merrill, Arthur J. Gold, Dorothy Q. Kellogg, Emi Uchida

School of Natural Resources: Faculty Publications

No abstract provided.


High Spatial Resolution Mapping Of Elevated Atmospheric Carbon Dioxide Using Airborne Imaging Spectroscopy: Radiative Transfer Modeling And Power Plant Plume Detection, Philip E. Dennison, Andrew K. Thorpe, Eric R. Pardyjak, Dar A. Roberts, Yi Qi, Robert O. Green, Eliza S. Bradley, Christopher C. Funk Jan 2013

High Spatial Resolution Mapping Of Elevated Atmospheric Carbon Dioxide Using Airborne Imaging Spectroscopy: Radiative Transfer Modeling And Power Plant Plume Detection, Philip E. Dennison, Andrew K. Thorpe, Eric R. Pardyjak, Dar A. Roberts, Yi Qi, Robert O. Green, Eliza S. Bradley, Christopher C. Funk

School of Natural Resources: Faculty Publications

No abstract provided.


Atrazine And Nitrate In Public Drinking Water Supplies And Non-Hodgkin Lymphoma In Nebraska, Usa, Martha G. Rhoades, Jane L. Meza, Cheryl L. Beseler, Patrick J. Shea, Andy Kahle, Julie M. Vose, Kent M. Eskridge, Roy F. Spalding Jan 2013

Atrazine And Nitrate In Public Drinking Water Supplies And Non-Hodgkin Lymphoma In Nebraska, Usa, Martha G. Rhoades, Jane L. Meza, Cheryl L. Beseler, Patrick J. Shea, Andy Kahle, Julie M. Vose, Kent M. Eskridge, Roy F. Spalding

School of Natural Resources: Faculty Publications

A secondary analysis of 1999–2002 Nebraska case-control data was conducted to assess the risk of non-Hodgkin lymphoma (NHL) associated with exposure to nitrate- and atrazine-contaminated drinking water. Water chemistry data were collected and weighted by well contribution and proximity of residence to water supply, followed by logistic regression to determine odds ratios (OR) and 95% confidence intervals (CI). We found no association between NHL risk and exposure to drinking water containing atrazine or nitrate alone. Risk associated with the interaction of nitrate and atrazine in drinking water was elevated (OR, 2.5; CI, 1.0–6.2). Risk of indolent B-cell lymphoma was higher …


Validation Of Noah-Simulated Soil Temperature In The North American Land Data Assimilation System Phase 2, Youlong Xia, Michael Ek, Justin Sheffield, Ben Livneh, Maoyi Huang, Helin Wei, Song Feng, Lifeng Luo, Jesse Meng, Eric Wood Jan 2013

Validation Of Noah-Simulated Soil Temperature In The North American Land Data Assimilation System Phase 2, Youlong Xia, Michael Ek, Justin Sheffield, Ben Livneh, Maoyi Huang, Helin Wei, Song Feng, Lifeng Luo, Jesse Meng, Eric Wood

School of Natural Resources: Faculty Publications

Soil temperature can exhibit considerable memory from weather and climate signals and is among the most important initial conditions in numerical weather and climate models. Consequently, a more accurate long term land surface soil temperature dataset is needed to improve weather and climate simulation and prediction, and is also important for the simulation of agricultural crop yield and ecological processes. The North American Land Data Assimilation phase 2 (NLDAS-2) has generated 31 years (1979–2009) of simulated hourly soil temperature data with a spatial resolution of 1/8°. This dataset has not been comprehensively evaluated to date. Thus, the purpose of this …


Nondetection Sampling Bias In Marked Presence-Only Data, Trevor Hefley, Andrew J. Tyre, David M. Baasch, Erin E. Blankenship Jan 2013

Nondetection Sampling Bias In Marked Presence-Only Data, Trevor Hefley, Andrew J. Tyre, David M. Baasch, Erin E. Blankenship

School of Natural Resources: Faculty Publications

1 Species distribution models (SDM) are tools used to determine environmental features that influence the geographic distribution of species’ abundance and have been used to analyze presence-only records. Analysis of presenceonly records may require correction for nondetection sampling bias to yield reliable conclusions. In addition, individuals of some species of animals may be highly aggregated and standard SDMs ignore environmental features that may influence aggregation behavior.

2 We contend that nondetection sampling bias can be treated as missing data. Statistical theory and corrective methods are well developed for missing data, but have been ignored in the literature on SDMs. We …


Correction Of Location Errors For Presence-Only Species Distribution Models, Trevor Hefley, David M. Baasch, Andrew J. Tyre, Erin E. Blankenship Jan 2013

Correction Of Location Errors For Presence-Only Species Distribution Models, Trevor Hefley, David M. Baasch, Andrew J. Tyre, Erin E. Blankenship

School of Natural Resources: Faculty Publications

1. Species distribution models (SDMs) for presence-only data depend on accurate and precise measurements of geographical and environmental covariates that influence presence and abundance of the species. Some data sets, however, may contain both systematic and random errors in the recorded location of the species. Environmental covariates at the recorded location may differ from those at the true location and result in biased parameter estimates and predictions from SDMs.

2. Regression calibration is a well-developed statistical method that can be used to correct the bias in estimated coefficients and predictions from SDMs when the recorded geographical location differs from the …


Statistical Indicators And State–Space Population Models Predict Extinction In A Population Of Bobwhite Quail, Trevor Hefley, Andrew J. Tyre, Erin E. Blankenship Jan 2013

Statistical Indicators And State–Space Population Models Predict Extinction In A Population Of Bobwhite Quail, Trevor Hefley, Andrew J. Tyre, Erin E. Blankenship

School of Natural Resources: Faculty Publications

Early warning systems of extinction thresholds have been developed for and tested in microcosm experiments, but have not been applied to populations of wild animals. We used state–space population models and a statistical indicator to detect a transcritical bifurcation extinction threshold in a population of bobwhite quail (Colinus virginianus) located in an agricultural region experiencing habitat deterioration and loss. The extinction threshold was detectible using two independent data sets. We compared predictions from state–space population models to predictions from a statistical indicator and found that predictions were corroborated. Using state–space population models, we estimated that our study population …


Miscanthus Establishment And Overwintering In The Midwest Usa: A Regional Modeling Study Of Crop Residue Management On Critical Minimum Soil Temperatures, Christopher J. Kucharik, Andy Vanloocke, John D. Lenters, Melissa M. Motew Jan 2013

Miscanthus Establishment And Overwintering In The Midwest Usa: A Regional Modeling Study Of Crop Residue Management On Critical Minimum Soil Temperatures, Christopher J. Kucharik, Andy Vanloocke, John D. Lenters, Melissa M. Motew

School of Natural Resources: Faculty Publications

Miscanthus is an intriguing cellulosic bioenergy feedstock because its aboveground productivity is high for low amounts of agrochemical inputs, but soil temperatures below ‒3.5°C could threaten successful cultivation in temperate regions. We used a combination of observed soil temperatures and the Agro-IBIS model to investigate how strategic residue management could reduce the risk of rhizome threatening soil temperatures. This objective was addressed using a historical (1978–2007) reconstruction of extreme minimum 10 cm soil temperatures experienced across the Midwest US and model sensitivity studies that quantified the impact of crop residue on soil temperatures. At observation sites and for simulations that …


Assessing Migration Of Ruby-Throated Hummingbirds (Archilochus Colubris) At Broad Spatial And Temporal Scales Evaluación De La Migración De Archilochus Colubris A Escalas Amplias De Tiempo Y Espacio, Jason Courter, Ron J. Johnson, William C. Bridges Jr., Kenneth Hubbard Jan 2013

Assessing Migration Of Ruby-Throated Hummingbirds (Archilochus Colubris) At Broad Spatial And Temporal Scales Evaluación De La Migración De Archilochus Colubris A Escalas Amplias De Tiempo Y Espacio, Jason Courter, Ron J. Johnson, William C. Bridges Jr., Kenneth Hubbard

School of Natural Resources: Faculty Publications

Phenological patterns in birds appear to be temperature-dependent in part, and global temperatures are undergoing change. Many studies of bird phenology are conducted at broad temporal but local spatial scales, making it difficult to assess how temperature affects bird migration across landscapes. Recently, networks of “citizen science” volunteers have emerged whose collective efforts may improve phenology studies as biases associated with such efforts are recognized and addressed. We compared mean Rubythroated Hummingbird (Archilochus colubris) first arrival dates from Journey North (2001-2010) with data from the North American Bird Phenology Program (1880-1969). Ruby-throated Hummingbirds arrived earlier in the more recent period …


The Agricultural Model Intercomparison And Improvement Project (Agmip): Protocols And Pilot Studies, Cynthia Rosenzweig, J. W. Jones, J. L. Hatfield, Alex Ruane, K. J. Thornburn, J. M. Antle, G. C. Nelson, C. Porter, S. Janssen, B. Basso, F. Ewert, D. Wallach, G. Baigorria, J. M. Winter Jan 2013

The Agricultural Model Intercomparison And Improvement Project (Agmip): Protocols And Pilot Studies, Cynthia Rosenzweig, J. W. Jones, J. L. Hatfield, Alex Ruane, K. J. Thornburn, J. M. Antle, G. C. Nelson, C. Porter, S. Janssen, B. Basso, F. Ewert, D. Wallach, G. Baigorria, J. M. Winter

School of Natural Resources: Faculty Publications

The Agricultural Model Intercomparison and Improvement Project (AgMIP) is a major international effort linking the climate, crop, and economic modeling communities with cutting-edge information technology to produce improved crop and economic models and the next generation of climate impact projections for the agricultural sector. The goals of AgMIP are to improve substantially the characterization of world food security due to climate change and to enhance adaptation capacity in both developing and developed countries. Analyses of the agricultural impacts of climate variability and change require a transdisciplinary effort to consistently link state-of-the-art climate scenarios to crop and economic models. Crop model …


The Agricultural Model Intercomparison And Improvement Project (Agmip): Protocols And Pilot Studies, Cynthia Rosenzweig, J. W. Jones, J. L. Hatfield, A. C. Ruane, K. J. Boote, P. Thornburn, J. M. Antle, G. C. Nelson, C. Porter, S. Janssen, S. Asseng, B. Basso, F. Ewert, D. Wallach, G. Baigorria, J. M. Winter Jan 2013

The Agricultural Model Intercomparison And Improvement Project (Agmip): Protocols And Pilot Studies, Cynthia Rosenzweig, J. W. Jones, J. L. Hatfield, A. C. Ruane, K. J. Boote, P. Thornburn, J. M. Antle, G. C. Nelson, C. Porter, S. Janssen, S. Asseng, B. Basso, F. Ewert, D. Wallach, G. Baigorria, J. M. Winter

School of Natural Resources: Faculty Publications

The Agricultural Model Intercomparison and Improvement Project (AgMIP) is a major international effort linking the climate, crop, and economic modeling communities with cutting-edge information technology to produce improved crop and economic models and the next generation of climate impact projections for the agricultural sector. The goals of AgMIP are to improve substantially the characterization of world food security due to climate change and to enhance adaptation capacity in both developing and developed countries. Analyses of the agricultural impacts of climate variability and change require a transdisciplinary effort to consistently link state-of-the-art climate scenarios to crop and economic models. Crop model …


Spatial And Temporal Unpredictability Of Colony Size In Cliff Swallows Across 30 Years, Charles R. Brown, Mary Bomberger Brown, Erin A. Roche Jan 2013

Spatial And Temporal Unpredictability Of Colony Size In Cliff Swallows Across 30 Years, Charles R. Brown, Mary Bomberger Brown, Erin A. Roche

School of Natural Resources: Faculty Publications

Most colonially breeding animals occupy colonies that range in size from a few pairs to thousands of individuals, but the causes of colony size variation are largely unknown. Three general hypotheses are: (1) that variation in colony size is maintained by fluctuating selection via spatial and temporal changes in fitness associated with different colony sizes; (2) that colony formation reflects heterogeneity in habitat, with some sites having resources to support more individuals than others; and (3) that individuals assess the presence or annual reproductive success of current colony residents at each site and aggregate preferentially at high-quality sites. These hypotheses …


The Relative Importance Of Exogenous And Substrate-Derived Nitrogen For Microbial Growth During Leaf Decomposition, B. M. Cheever, J. R. Webster, E. E. Bilger, S. A. Thomas Jan 2013

The Relative Importance Of Exogenous And Substrate-Derived Nitrogen For Microbial Growth During Leaf Decomposition, B. M. Cheever, J. R. Webster, E. E. Bilger, S. A. Thomas

School of Natural Resources: Faculty Publications

Heterotrophic microbes colonizing detritus obtain nitrogen (N) for growth by assimilating N from their substrate or immobilizing exogenous inorganic N. Microbial use of these two pools has different implications for N cycling and organic matter decomposition in the face of the global increase in biologically available N. We used sugar maple leaves labeled with 15N to differentiate between microbial N that had been assimilated from the leaf substrate (enriched with 15N) or immobilized from the water (natural abundance 15N:14N) in five Appalachian streams ranging in ambient NO3-N concentrations from about 5 to 900 …


2013 Interior Least Tern And Piping Plover Monitoring, Research, Management, And Outreach Report For The Lower Platte River, Nebraska, Mary Bomberger Brown, Joel G. Jorgensen, Lauren R. Dinan Jan 2013

2013 Interior Least Tern And Piping Plover Monitoring, Research, Management, And Outreach Report For The Lower Platte River, Nebraska, Mary Bomberger Brown, Joel G. Jorgensen, Lauren R. Dinan

School of Natural Resources: Faculty Publications

This document reports on our monitoring, research, management, and outreach activities during the past 12 months (2012–2013). We prepared it to inform our partners, cooperating agencies, funding sources, and other interested parties of our activities and to provide a preliminary summary of our results.

The lower Platte River and its major tributaries provide important nesting and migratory stopover habitat for two bird species of special conservation concern: the state and federally endangered Interior Least Tern (Sternula antillarum athalassos) and threatened Piping Plover (Charadrius melodus). The Tern and Plover Conservation Partnership (TPCP), based at the University of …


Surface Energy Balance Model Of Transpiration From Variable Canopy Cover And Evaporation From Residue-Covered Or Bare Soil Systems: Model Evaluation, Luis Octavio Lagos, Derrel Martin, Shashi B. Verma, Suat Irmak, Ayse Kilic, Dean E. Eisenhauer, Andrew E. Suyker Jan 2013

Surface Energy Balance Model Of Transpiration From Variable Canopy Cover And Evaporation From Residue-Covered Or Bare Soil Systems: Model Evaluation, Luis Octavio Lagos, Derrel Martin, Shashi B. Verma, Suat Irmak, Ayse Kilic, Dean E. Eisenhauer, Andrew E. Suyker

School of Natural Resources: Faculty Publications

A surface energy balance model (SEB) was extended by Lagos et al. Irrig Sci 28:51–64 (2009) to estimate evapotranspiration (ET) from variable canopy cover and evaporation from residue-covered or bare soil systems. The model estimates latent, sensible, and soil heat fluxes and provides a method to partition evapotranspiration into soil/residue evaporation and plant transpiration. The objective of this work was to perform a sensitivity analysis of model parameters and evaluate the performance of the proposed model to estimate ET during the growing and non-growing season of maize (Zea Mays L.) and soybeans (Glycine max) in eastern …


The Influence Of Different Cover Types On American Robin Nest Success In Organic Agroecosystems, John E. Quinn, Amy I. Oden, James R. Brandle Jan 2013

The Influence Of Different Cover Types On American Robin Nest Success In Organic Agroecosystems, John E. Quinn, Amy I. Oden, James R. Brandle

School of Natural Resources: Faculty Publications

There are many opportunities for biodiversity conservation in organic farm systems. Successful and sustainable conservation efforts in organic systems, however, need to measure appropriate outcomes. In particular, data are needed on the breeding success of associated wildlife species. We measured nesting success of the American Robin (Turdus migratorius) in woodlands embedded within eight organic farms in eastern Nebraska. We modeled daily nest survival rate to identify land use and land cover patterns that optimize conservation of birds in organic farm systems. The percentage of a crop in the fields adjacent to linear woodlands best predicted daily survival rate. …


Field Guide For Nebraska Invasive Plants (Fg-27) Jan 2013

Field Guide For Nebraska Invasive Plants (Fg-27)

School of Natural Resources: Faculty Publications

What are Invasive Species: Invasive species are non-native organisms introduced into new ecosystem whose introduction and ability to spread causes environmental or economic harm, or harm to human health. Once established, these species cause irreparable harm, including: introducing disease; competing with native specics; changing the physical characteristics of natural areas; and negatively impacting local and national economies.

Invasive Species Regulations: This guide identifies federal and state-listed noxious weeds. Federal noxious weeds are regulated by the U.S. Department of Agriculture; State noxious weeds are regulated by the Nebraska Department of Agriculture Animal and Plant Health Noxious Weed Program. Aquatic invasive …


A Farm-Scale Biodiversity And Ecosystem Services Assessment Tool: The Healthy Farm Index, John E. Quinn, James R. Brandle, Ron J. Johnson Jan 2013

A Farm-Scale Biodiversity And Ecosystem Services Assessment Tool: The Healthy Farm Index, John E. Quinn, James R. Brandle, Ron J. Johnson

School of Natural Resources: Faculty Publications

Farm management focused on maximizing biomass production results in biological simplification and ultimately a degraded production potential for the future. Despite the large and growing body of evidence pointing to the need to restore biodiversity to farm systems, incorporation of biodiversity and ecosystem services into local agricultural land use decision- making remains limited. The lack of planned and associated biodiversity may reduce resiliency of local managed ecosystems and add management costs; however, the trade-off for individual landowners of greater diversity is increased management complexity and uncertainty. To assist farmers in managing biodiversity and to encourage ecological thinking, we developed the …


Drought And Corn In Kentucky, Rezaul Mahmood Jan 2013

Drought And Corn In Kentucky, Rezaul Mahmood

School of Natural Resources: Faculty Publications

No abstract provided.


Did Irrigation Impact 20th Century Temperature In The High Plains Aquifer Region?, Rezaul Mahmood Jan 2013

Did Irrigation Impact 20th Century Temperature In The High Plains Aquifer Region?, Rezaul Mahmood

School of Natural Resources: Faculty Publications

No abstract provided.


Insights From Characterizing Extinct Human Gut Microbiomes, Raul Y. Tito, Dan Knights, Jessica Metcalf, Alexandra J. Obregon-Tito, Lauren Cleeland, Fares Najar, Bruce Roe, Karl Reinhard, Kristin Sobolik, Samuel Belknap, Morris Foster, Paul Spicer, Rob Knight, Cecil M. Lewis, Jr. Dec 2012

Insights From Characterizing Extinct Human Gut Microbiomes, Raul Y. Tito, Dan Knights, Jessica Metcalf, Alexandra J. Obregon-Tito, Lauren Cleeland, Fares Najar, Bruce Roe, Karl Reinhard, Kristin Sobolik, Samuel Belknap, Morris Foster, Paul Spicer, Rob Knight, Cecil M. Lewis, Jr.

School of Natural Resources: Faculty Publications

In an effort to better understand the ancestral state of the human distal gut microbiome, we examine feces retrieved from archaeological contexts (coprolites). To accomplish this, we pyrosequenced the 16S rDNA V3 region from duplicate coprolite samples recovered from three archaeological sites, each representing a different depositional environment: Hinds Cave (~8000 years B.P.) in the southern United States, Caserones (1600 years B.P.) in northern Chile, and Rio Zape in northern Mexico (1400 years B.P.). Clustering algorithms grouped samples from the same site. Phyletic representation was more similar within sites than between them. A Bayesian approach to source-tracking was used to …


Evolutionary And Practical Implications Of Pseudo-Estrus Behavior In Florida Panthers (Puma Concolor Coryi), John F. Benson, Mark A. Lotz, E. Darrell Land, Dave P. Onorato Nov 2012

Evolutionary And Practical Implications Of Pseudo-Estrus Behavior In Florida Panthers (Puma Concolor Coryi), John F. Benson, Mark A. Lotz, E. Darrell Land, Dave P. Onorato

School of Natural Resources: Faculty Publications

Estrus behavior by females for reasons other than reproduction (pseudo-estrus) has been reported in species of primates and felids, and alternative hypotheses have been put forth to explain its evolution and function. We observed 3 separate cases of pseudo-estrus behavior by 2 Puma concolor coryi (Florida Panther) females while they were nursing young (old) kittens. We used VHF and GPS telemetry data, genetic pedigree analysis, and visual observations to provide insight into the evolutionary and practical implications of this behavior for Panthers. We suggest that female Panthers likely consort with males while nursing kittens to maintain amicable relations with these …


Comparative Transcriptome Analysis Of Two Olive Cultivars In Response To Nacl-Stress, Christos Bazakos, Maria E. Manioudaki, Ioannis Therios, Demetrios Voyiatzis, Dimitris Kafetzopoulos, Tala Awada, Panagiotis Kalaitzis Aug 2012

Comparative Transcriptome Analysis Of Two Olive Cultivars In Response To Nacl-Stress, Christos Bazakos, Maria E. Manioudaki, Ioannis Therios, Demetrios Voyiatzis, Dimitris Kafetzopoulos, Tala Awada, Panagiotis Kalaitzis

School of Natural Resources: Faculty Publications

Background: Olive (Olea europaea L.) cultivation is rapidly expanding and low quality saline water is often used for irrigation. The molecular basis of salt tolerance in olive, though, has not yet been investigated at a system level. In this study a comparative transcriptomics approach was used as a tool to unravel gene regulatory networks underlying salinity response in olive trees by simulating as much as possible olive growing conditions in the field. Specifically, we investigated the genotype-dependent differences in the transcriptome response of two olive cultivars, a salt-tolerant and a salt-sensitive one.

Methodology/Principal Findings: A 135-day long …


Flow, Nutrients, And Light Availability Influence Neotropical Epilithon Biomass And Stoichiometry, Tyler J. Kohler, Thomas N. Heatherly Ii, Rana W. El-Sabaawi, Eugenia Zandona, Michael C. Marshall, Alexander S. Flecker, Catherine M. Pringle, David N. Reznick, Steven A. Thomas Aug 2012

Flow, Nutrients, And Light Availability Influence Neotropical Epilithon Biomass And Stoichiometry, Tyler J. Kohler, Thomas N. Heatherly Ii, Rana W. El-Sabaawi, Eugenia Zandona, Michael C. Marshall, Alexander S. Flecker, Catherine M. Pringle, David N. Reznick, Steven A. Thomas

School of Natural Resources: Faculty Publications

Light, nutrient availability, and flow are strong factors controlling the elemental composition and biomass of epilithon in temperate stream ecosystems. However, comparatively little is known about these relationships in tropical streams. We investigated how gradients of light and nutrient availability, seasonality, and habitat influenced epilithon biomass, chlorophyll a, and nutrient ratios in montane streams of Trinidad, West Indies. We sampled 4 focal tributaries of a single river, 2 of which had canopies experimentally thinned, every other month over a 2-y period to observe temporal dynamics and light effects on epilithon. We also sampled 18 sites across Trinidad’s Northern Range Mountains …


Denitrification By Sulfur-Oxidizing Bacteria In A Eutrophic Lake, Amy J. Burgin, Stephen K. Hamilton, Stuart E. Jones, Jay T. Lennon Jul 2012

Denitrification By Sulfur-Oxidizing Bacteria In A Eutrophic Lake, Amy J. Burgin, Stephen K. Hamilton, Stuart E. Jones, Jay T. Lennon

School of Natural Resources: Faculty Publications

Understanding the mechanistic controls of microbial denitrification is of central importance to both environmental microbiology and ecosystem ecology. Loss of nitrate (NO3 −) is often attributed to carbon-driven (heterotrophic) denitrification. However, denitrification can also be coupled to sulfur (S) oxidation by chemolithoautotrophic bacteria. In the present study, we used an in situ stable isotope (15NO3 −) tracer addition in combination with molecular approaches to understand the contribution of sulfur-oxidizing bacteria to the reduction of NO3 − in a eutrophic lake. Samples were incubated across a total dissolved sulfide (H2S) gradient (2 to …


Impacts Of An Invasive Snail (Tarebia Granifera) On Nutrient Cycling In Tropical Streams: The Role Of Riparian Deforestation In Trinidad, West Indies, Jennifer M. Moslemi, Sunny B. Snider, Keeley Macneill, James F. Gilliam, Alexander S. Flecker Jun 2012

Impacts Of An Invasive Snail (Tarebia Granifera) On Nutrient Cycling In Tropical Streams: The Role Of Riparian Deforestation In Trinidad, West Indies, Jennifer M. Moslemi, Sunny B. Snider, Keeley Macneill, James F. Gilliam, Alexander S. Flecker

School of Natural Resources: Faculty Publications

Non-native species and habitat degradation are two major catalysts of environmental change and often occur simultaneously. In freshwater systems, degradation of adjacent terrestrial vegetation may facilitate introduced species by altering resource availability. Here we examine how the presence of intact riparian cover influences the impact of an invasive herbivorous snail, Tarebia granifera, on nitrogen (N) cycling in aquatic systems on the island of Trinidad. We quantified snail biomass, growth, and N excretion in locations where riparian vegetation was present or removed to determine how snail demographics and excretion were related to the condition of the riparian zone. In three …