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University of Vermont

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2017

Articles 1 - 30 of 52

Full-Text Articles in Physical Sciences and Mathematics

Evaluating Spatial Variability In Sediment And Phosphorus Concentration-Discharge Relationships Using Bayesian Inference And Self-Organizing Maps, Kristen L. Underwood, Donna M. Rizzo, Andrew W. Schroth, Mandar M. Dewoolkar Dec 2017

Evaluating Spatial Variability In Sediment And Phosphorus Concentration-Discharge Relationships Using Bayesian Inference And Self-Organizing Maps, Kristen L. Underwood, Donna M. Rizzo, Andrew W. Schroth, Mandar M. Dewoolkar

College of Engineering and Mathematical Sciences Faculty Publications

Given the variable biogeochemical, physical, and hydrological processes driving fluvial sediment and nutrient export, the water science and management communities need data-driven methods to identify regions prone to production and transport under variable hydrometeorological conditions. We use Bayesian analysis to segment concentration-discharge linear regression models for total suspended solids (TSS) and particulate and dissolved phosphorus (PP, DP) using 22 years of monitoring data from 18 Lake Champlain watersheds. Bayesian inference was leveraged to estimate segmented regression model parameters and identify threshold position. The identified threshold positions demonstrated a considerable range below and above the median discharge—which has been used previously …

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Catastrophic Failure Of Nacre Under Pure Shear Stresses Of Torsion, Saleh Alghamdi, Ting Tan, Christopher Hale-Sills, Floyd Vilmont, Tian Xia, Jie Yang, Dryver Huston, Mandar Dewoolkar Dec 2017

Catastrophic Failure Of Nacre Under Pure Shear Stresses Of Torsion, Saleh Alghamdi, Ting Tan, Christopher Hale-Sills, Floyd Vilmont, Tian Xia, Jie Yang, Dryver Huston, Mandar Dewoolkar

College of Engineering and Mathematical Sciences Faculty Publications

Nacre, a composite made from biogenic aragonite and proteins, exhibits excellent strength and toughness. Here, we show that nacreous sections can exhibit complete brittle fracture along the tablet interfaces at the proportional limit under pure shear stresses of torsion. We quantitatively separate the initial tablet sliding primarily resisted by nanoscale aragonite pillars from the following sliding resisted by various microscale toughening mechanisms. We postulate that the ductility of nacre can be limited by eliminating tablet interactions during crack propagations. Our findings should help pursuing further insights of layered materials by using torsion.

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Mining Drives Extensive Deforestation In The Brazilian Amazon, Laura J. Sonter, Diego Herrera, Damian J. Barrett, Gillian L. Galford, Chris J. Moran, Britaldo S. Soares-Filho Dec 2017

Mining Drives Extensive Deforestation In The Brazilian Amazon, Laura J. Sonter, Diego Herrera, Damian J. Barrett, Gillian L. Galford, Chris J. Moran, Britaldo S. Soares-Filho

Rubenstein School of Environment and Natural Resources Faculty Publications

Mining poses significant and potentially underestimated risks to tropical forests worldwide. In Brazil's Amazon, mining drives deforestation far beyond operational lease boundaries, yet the full extent of these impacts is unknown and thus neglected in environmental licensing. Here we quantify mining-induced deforestation and investigate the aspects of mining operations, which most likely contribute. We find mining significantly increased Amazon forest loss up to 70 km beyond mining lease boundaries, causing 11,670 km2 of deforestation between 2005 and 2015. This extent represents 9% of all Amazon forest loss during this time and 12 times more deforestation than occurred within mining leases …

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A Multi-Country Assessment Of Factors Related To Smallholder Food Security In Varying Rainfall Conditions, Meredith T. Niles, Molly E. Brown Dec 2017

A Multi-Country Assessment Of Factors Related To Smallholder Food Security In Varying Rainfall Conditions, Meredith T. Niles, Molly E. Brown

College of Agriculture and Life Sciences Faculty Publications

Given that smallholder farmers are frequently food insecure and rely significantly on rain-fed agriculture, it is critical to examine climate variability and food insecurity. We utilize data from smallholder farmer surveys from 12 countries with 30 years of rainfall data to examine how rainfall variability and household resources are correlated with food security. We find that on average, households that experienced a drier than average year are 3.81 months food insecure, while households within a normal range of rainfall were 3.67 months food insecure, and wetter than average households were 2.86 months food insecure. Reduced odds of food insecurity is …

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Genomic Signature Of Adaptive Divergence Despite Strong Nonadaptive Forces On Edaphic Islands: A Case Study Of Primulina Juliae, Jing Wang, Chao Feng, Tenglong Jiao, Eric Bishop Von Wettberg, Ming Kang Dec 2017

Genomic Signature Of Adaptive Divergence Despite Strong Nonadaptive Forces On Edaphic Islands: A Case Study Of Primulina Juliae, Jing Wang, Chao Feng, Tenglong Jiao, Eric Bishop Von Wettberg, Ming Kang

College of Agriculture and Life Sciences Faculty Publications

Both genetic drift and divergent selection are expected to be strong evolutionary forces driving population differentiation on edaphic habitat islands. However, the relative contribution of genetic drift and divergent selection to population divergence has rarely been tested simultaneously. In this study, restriction-site associated DNA-based population genomic analyses were applied to assess the relative importance of drift and divergent selection on population divergence of Primulina juliae, an edaphic specialist fromsouthern China. All populations were found with low standing genetic variation, small effective population size (NE), and signatures of bottlenecks. Populations with the lowest genetic variation were most genetically differentiated from other …

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The Complete Chloroplast Genome Of Primulina And Two Novel Strategies For Development Of High Polymorphic Loci For Population Genetic And Phylogenetic Studies, Chao Feng, Meizhen Xu, Chen Feng, Eric J.B. Von Wettberg, Ming Kang Nov 2017

The Complete Chloroplast Genome Of Primulina And Two Novel Strategies For Development Of High Polymorphic Loci For Population Genetic And Phylogenetic Studies, Chao Feng, Meizhen Xu, Chen Feng, Eric J.B. Von Wettberg, Ming Kang

College of Agriculture and Life Sciences Faculty Publications

Background: Primulina Hance is an emerging model for studying evolutionary divergence, adaptation and speciation of the karst flora. However, phylogenetic relationships within the genus have not been resolved due to low variation detected in the cpDNA regions. Chloroplast genomes can provide important information for phylogenetic and population genetic studies. Recent advances in next-generation sequencing (NGS) techniques greatly facilitate sequencing whole chloroplast genomes for multiple individuals. Consequently, novel strategies for development of highly polymorphic loci for population genetic and phylogenetic studies based on NGS data are needed. Methods: For development of high polymorphic loci for population genetic and phylogenetic studies, two …

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Climate Change And Food Systems: Assessing Impacts And Opportunities, Meredith T. Niles, Richie Ahuja, Jimena M. Esquivel, Nelson Mango, Mil Duncan, Martin Heller, Cristina Tirado Nov 2017

Climate Change And Food Systems: Assessing Impacts And Opportunities, Meredith T. Niles, Richie Ahuja, Jimena M. Esquivel, Nelson Mango, Mil Duncan, Martin Heller, Cristina Tirado

College of Agriculture and Life Sciences Faculty Publications

No abstract provided.

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Deciphering The Enigma Of Undetected Species, Phylogenetic, And Functional Diversity Based On Good-Turing Theory, Anne Chao, Chun Huo Chiu, Robert K. Colwell, Luiz Fernando S. Magnago, Robin L. Chazdon, Nicholas J. Gotelli Nov 2017

Deciphering The Enigma Of Undetected Species, Phylogenetic, And Functional Diversity Based On Good-Turing Theory, Anne Chao, Chun Huo Chiu, Robert K. Colwell, Luiz Fernando S. Magnago, Robin L. Chazdon, Nicholas J. Gotelli

College of Arts and Sciences Faculty Publications

Estimating the species, phylogenetic, and functional diversity of a community is challenging because rare species are often undetected, even with intensive sampling. The Good-Turing frequency formula, originally developed for cryptography, estimates in an ecological context the true frequencies of rare species in a single assemblage based on an incomplete sample of individuals. Until now, this formula has never been used to estimate undetected species, phylogenetic, and functional diversity. Here, we first generalize the Good-Turing formula to incomplete sampling of two assemblages. The original formula and its two-assemblage generalization provide a novel and unified approach to notation, terminology, and estimation of …

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A Comprehensive Framework For The Study Of Species Co-Occurrences, Nestedness And Turnover, Werner Ulrich, Wojciech Kryszewski, Piotr Sewerniak, Radosław Puchałka, Giovanni Strona, Nicholas J. Gotelli Nov 2017

A Comprehensive Framework For The Study Of Species Co-Occurrences, Nestedness And Turnover, Werner Ulrich, Wojciech Kryszewski, Piotr Sewerniak, Radosław Puchałka, Giovanni Strona, Nicholas J. Gotelli

College of Arts and Sciences Faculty Publications

Binary presence–absence matrices (rows = species, columns = sites) are often used to quantify patterns of species co-occurrence, and to infer possible biotic interactions from these patterns. Previous classifications of co-occurrence patterns as nested, segregated, or modular have led to contradictory results and conclusions. These analyses usually do not incorporate the functional traits of the species or the environmental characteristics of the sites, even though the outcomes of species interactions often depend on trait expression and site quality. Here we address this shortcoming by developing a method that incorporates realized functional and environmental niches, and relates them to species co-occurrence …

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Isolation By Distance, Not Rivers, Control The Distribution Of Termite Species In The Amazonian Rain Forest, Cristian S. Dambros, José W. Morais, Renato A. Azevedo, Nicholas J. Gotelli Oct 2017

Isolation By Distance, Not Rivers, Control The Distribution Of Termite Species In The Amazonian Rain Forest, Cristian S. Dambros, José W. Morais, Renato A. Azevedo, Nicholas J. Gotelli

College of Arts and Sciences Faculty Publications

The spatial distribution of species is affected by dispersal barriers, local environmental conditions and climate. However, the effect of species dispersal and their adaptation to the environment across geographic scales is poorly understood. To investigate the distribution of species from local to broad geographic scales, we sampled termites in 198 transects distributed in 13 sampling grids in the Brazilian Amazonian forest. The sampling grids encompassed an area of 271 500 km2 and included the five major biogeographic regions delimited by Amazonian rivers. Environmental data for each transect were obtained from local measurements and remote sensing. Similar to previous studies, termite …

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Environmental Proteomics Reveals Taxonomic And Functional Changes In An Enriched Aquatic Ecosystem, Amanda C. Northrop, Rachel K. Brooks, Aaron M. Ellison, Nicholas J. Gotelli, Bryan A. Ballif Oct 2017

Environmental Proteomics Reveals Taxonomic And Functional Changes In An Enriched Aquatic Ecosystem, Amanda C. Northrop, Rachel K. Brooks, Aaron M. Ellison, Nicholas J. Gotelli, Bryan A. Ballif

College of Arts and Sciences Faculty Publications

Aquatic ecosystem enrichment can lead to distinct and irreversible changes to undesirable states. Understanding changes in active microbial community function and composition following organic matter loading in enriched ecosystems can help identify biomarkers of such state changes. In a field experiment, we enriched replicate aquatic ecosystems in the pitchers of the northern pitcher plant, Sarracenia purpurea. Shotgun metaproteomics using a custom metagenomic database identified proteins, molecular pathways, and contributing microbial taxa that differentiated control ecosystems from those that were enriched. The number of microbial taxa contributing to protein expression was comparable between treatments; however, taxonomic evenness was higher in controls. …

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Studying Human Behavior For Species Conservation, Hilary Byerly, Brendan Fisher Oct 2017

Studying Human Behavior For Species Conservation, Hilary Byerly, Brendan Fisher

Rubenstein School of Environment and Natural Resources Faculty Publications

No abstract provided.

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Identifying The Spatial Pattern And Importance Of Hydro-Geomorphic Drainage Impairments On Unpaved Roads In The Northeastern Usa, Beverley C. Wemple, Gordon E. Clark, Donald S. Ross, Donna M. Rizzo Sep 2017

Identifying The Spatial Pattern And Importance Of Hydro-Geomorphic Drainage Impairments On Unpaved Roads In The Northeastern Usa, Beverley C. Wemple, Gordon E. Clark, Donald S. Ross, Donna M. Rizzo

College of Arts and Sciences Faculty Publications

Roads have been widely studied as sources of runoff and sediment and identified as pollutant production sources to receiving waters. Despite the wealth of research on logging roads in forested, upland settings, little work has been conducted to examine the role of extensive networks of rural, low-volume, unpaved roads on water quality degradation at the catchment scale. We studied a network of municipal unpaved roads in the northeastern US to identify the type and spatial extent of ‘hydro-geomorphic impairments’ to water quality. We mapped erosional and depositional features on roads to develop an estimate of pollutant production. We also mapped …

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Ecological Network Metrics: Opportunities For Synthesis, Matthew K. Lau, Stuart R. Borrett, Benjamin Baiser, Nicholas J. Gotelli, Aaron M. Ellison Aug 2017

Ecological Network Metrics: Opportunities For Synthesis, Matthew K. Lau, Stuart R. Borrett, Benjamin Baiser, Nicholas J. Gotelli, Aaron M. Ellison

College of Arts and Sciences Faculty Publications

Network ecology provides a systems basis for approaching ecological questions, such as factors that influence biological diversity, the role of particular species or particular traits in structuring ecosystems, and long-term ecological dynamics (e.g., stability). Whereas the introduction of network theory has enabled ecologists to quantify not only the degree, but also the architecture of ecological complexity, these advances have come at the cost of introducing new challenges, including new theoretical concepts and metrics, and increased data complexity and computational intensity. Synthesizing recent developments in the network ecology literature, we point to several potential solutions to these issues: integrating network metrics …

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Mountain Forests And Sustainable Development: The Potential For Achieving The United Nations' 2030 Agenda, Georg Gratzer, William S. Keeton Aug 2017

Mountain Forests And Sustainable Development: The Potential For Achieving The United Nations' 2030 Agenda, Georg Gratzer, William S. Keeton

Rubenstein School of Environment and Natural Resources Faculty Publications

The world is facing numerous and severe environmental, social, and economic challenges. To address these, in September 2015 the General Assembly of the United Nations adopted the resolution Transforming our World: The 2030 Agenda for Sustainable Development. The United Nations' 17 sustainable development goals (SDGs) and their 169 targets are ambitious, broadly encompassing, and indivisible. They are intended to guide nations and communities toward attaining healthy and peaceful livelihoods free of poverty and hunger. Collectively the goals envision sound and safe environments, where global threats like climate change are successfully combated through both mitigation and adaptation. Agenda 2030 envisages sustainable …

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Nutrient Leaching From Compost: Implications For Bioretention And Other Green Stormwater Infrastructure, Stephanie Hurley, Paliza Shrestha, Amanda Cording Aug 2017

Nutrient Leaching From Compost: Implications For Bioretention And Other Green Stormwater Infrastructure, Stephanie Hurley, Paliza Shrestha, Amanda Cording

College of Agriculture and Life Sciences Faculty Publications

This work is made available under the terms of the Creative Commons Attribution 4.0 International license,. Compost is often used as a soil amendment in gardens, agricultural fields, and other landscaped systems to alter soil biophysical characteristics and increase availability of valuable nutrients including nitrogen (N), phosphorus (P), and carbon (C). However, leaching of soluble nutrients from compost is of concern, particularly in wet settings, such as within green stormwater infrastructure, riparian areas, and floodplains. This research highlights the importance of saturation as an influencing factor on the nutrient leaching potential of different composts and compost-amended bioretention soils. Nutrient leaching …

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Community-Level Regulation Of Temporal Trends In Biodiversity, Nicholas J. Gotelli, Hideyasu Shimadzu, Maria Dornelas, Brian Mcgill, Faye Moyes, Anne E. Magurran Jul 2017

Community-Level Regulation Of Temporal Trends In Biodiversity, Nicholas J. Gotelli, Hideyasu Shimadzu, Maria Dornelas, Brian Mcgill, Faye Moyes, Anne E. Magurran

College of Arts and Sciences Faculty Publications

Many theoretical models of community dynamics predict that species richness (S) and total abundance (N) are regulated in their temporal fluctuations. We present novel evidence for widespread regulation of biodiversity. For 59 plant and animal assemblages from around the globe monitored annually for a decade or more, the majority exhibited regulated fluctuations compared to the null hypothesis of an unconstrained random walk. However, there was little evidence for statistical artifacts, regulation driven by correlations with average annual temperature, or local-scale compensatory fluctuations in S or N. In the absence of major environmental perturbations, such as urbanization or cropland transformation, species …

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Heat Tolerance Predicts The Importance Of Species Interaction Effects As The Climate Changes, Sarah E. Diamond, Lacy Chick, Clint A. Penick, Lauren M. Nichols, Sara Helms Cahan, Robert R. Dunn, Aaron M. Ellison, Nathan J. Sanders, Nicholas J. Gotelli Jul 2017

Heat Tolerance Predicts The Importance Of Species Interaction Effects As The Climate Changes, Sarah E. Diamond, Lacy Chick, Clint A. Penick, Lauren M. Nichols, Sara Helms Cahan, Robert R. Dunn, Aaron M. Ellison, Nathan J. Sanders, Nicholas J. Gotelli

College of Arts and Sciences Faculty Publications

Few studies have quantified the relative importance of direct effects of climate change on communities versus indirect effects that are mediated thorough species interactions, and the limited evidence is conflicting. Trait-based approaches have been popular in studies of climate change, but can they be used to estimate direct versus indirect effects? At the species level, thermal tolerance is a trait that is often used to predict winners and losers under scenarios of climate change. But thermal tolerance might also inform when species interactions are likely to be important because only subsets of species will be able to exploit the available …

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Accounting For Photodegradation Dramatically Improves Prediction Of Carbon Losses In Dryland Systems, E. Carol Adair, William J. Parton, Jennifer Y. King, Leslie A. Brandt, Yang Lin Jul 2017

Accounting For Photodegradation Dramatically Improves Prediction Of Carbon Losses In Dryland Systems, E. Carol Adair, William J. Parton, Jennifer Y. King, Leslie A. Brandt, Yang Lin

Rubenstein School of Environment and Natural Resources Faculty Publications

Traditional models of decomposition fail to capture litter mass loss patterns in dryland systems. This shortcoming has stimulated research into alternative drivers of decomposition, including photodegradation. Here, we use aboveground litter decomposition data for dryland (arid) sites from the Long-term Intersite Decomposition Experiment Team data set to test hypotheses (models) about the mechanisms and impacts of photodegradation. Incorporating photodegradation into a traditional biotic decomposition model substantially improved model predictions for mass loss at these dryland sites, especially after four years. The best model accounted for the effects of solar radiation via photodegradation loss from the intermediate cellulosic and lignin pools …

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Crowdsourced Delphis: Designing Solutions To Complex Environmental Problems With Broad Stakeholder Participation, Sarah Coleman, Stephanie Hurley, Christopher Koliba, Asim Zia Jul 2017

Crowdsourced Delphis: Designing Solutions To Complex Environmental Problems With Broad Stakeholder Participation, Sarah Coleman, Stephanie Hurley, Christopher Koliba, Asim Zia

College of Agriculture and Life Sciences Faculty Publications

There is a well-established need for increased stakeholder participation in the generation of adaptive management approaches and specific solutions to complex environmental problems. However, integrating participant feedback into current science, research, and decision-making processes is challenging. This paper presents a novel approach that marries a rigorous Delphi method, borrowed from policy and organizational sciences, with contemporary “crowdsourcing” to address the complex problems of water pollution exacerbated by climate change in the Lake Champlain Basin. In an online Delphi forum that occurred over a six-week period during the Spring of 2014, fifty-three participants proposed and commented on adaptive solutions to address …

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Crowdsourced Delphis: Designing Solutions To Complex Environmental Problems With Broad Stakeholder Participation, Sarah Coleman, Stephanie Hurley, Christopher Koliba, Asim Zia Jul 2017

Crowdsourced Delphis: Designing Solutions To Complex Environmental Problems With Broad Stakeholder Participation, Sarah Coleman, Stephanie Hurley, Christopher Koliba, Asim Zia

College of Agriculture and Life Sciences Faculty Publications

There is a well-established need for increased stakeholder participation in the generation of adaptive management approaches and specific solutions to complex environmental problems. However, integrating participant feedback into current science, research, and decision-making processes is challenging. This paper presents a novel approach that marries a rigorous Delphi method, borrowed from policy and organizational sciences, with contemporary “crowdsourcing” to address the complex problems of water pollution exacerbated by climate change in the Lake Champlain Basin. In an online Delphi forum that occurred over a six-week period during the Spring of 2014, fifty-three participants proposed and commented on adaptive solutions to address …

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Adults And Children In Low-Income Households That Participate In Cost-Offset Community Supported Agriculture Have High Fruit And Vegetable Consumption, Karla L. Hanson, Jane Kolodinsky, Weiwei Wang, Emily H. Morgan, Stephanie B. Jilcott Pitts, Alice S. Ammerman, Marilyn Sitaker, Rebecca A. Seguin Jul 2017

Adults And Children In Low-Income Households That Participate In Cost-Offset Community Supported Agriculture Have High Fruit And Vegetable Consumption, Karla L. Hanson, Jane Kolodinsky, Weiwei Wang, Emily H. Morgan, Stephanie B. Jilcott Pitts, Alice S. Ammerman, Marilyn Sitaker, Rebecca A. Seguin

College of Agriculture and Life Sciences Faculty Publications

Licensee MDPI, Basel, Switzerland. This paper examines fruit and vegetable intake (FVI) in low-income households that participated in a cost-offset (CO), or 50% subsidized, community-supported agriculture (CSA) program. CSA customers paid farms upfront for a share of the harvest, and received produce weekly throughout the growing season. A cohort of adults and children 2-12 y in a summer CO-CSA were surveyed online twice: August 2015 (n = 41) and February 2016 (n = 23). FVI was measured by the National Cancer Institute’s (NCI) Fruit and Vegetable Screener (FVS) and an inventory of locally grown fruits and vegetables. FVI relative to …

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Addressing Climate Change Impacts On Agriculture And Natural Resources: Barriers And Priorities For Land-Grant Universities In The Northeastern United States, Daniel Tobin, Rama Radhakrishna, Allison Chatrchyan, Shorna B. Allred Jul 2017

Addressing Climate Change Impacts On Agriculture And Natural Resources: Barriers And Priorities For Land-Grant Universities In The Northeastern United States, Daniel Tobin, Rama Radhakrishna, Allison Chatrchyan, Shorna B. Allred

College of Agriculture and Life Sciences Faculty Publications

Climate change has serious implications for agricultural production, natural resource management, and food security. In the United States, land-grant universities and the U.S. Cooperative Extension System have a critical role to play in conducting basic and applied research related to climate change and translating findings into meaningful programming. However, land-grant universities and Extension have had difficulty maintaining their roles as the preeminent source of trusted information on complex topics like climate change. To help guide research and programming agendas of land-grant universities, the authors explored the barriers and priorities that researchers and Extension personnel at 16 northeastern land-grant universities perceive …

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Evaluation Of A Proposal For Reliable Low-Cost Grid Power With 100% Wind, Water, And Solar, Christopher T.M. Clack, Staffan A. Qvist, Jay Apt, Morgan Bazilian, Adam R. Brandt, Ken Caldeira, Steven J. Davis, Victor Diakov, Mark A. Handschy, Paul D.H. Hines, Paulina Jaramillo, Daniel M. Kammen, Jane C.S. Long, M. Granger Morgan, Adam Reed, Varun Sivaram, James Sweeney, George R. Tynan, David G. Victor, John P. Weyant, Jay F. Whitacre Jun 2017

Evaluation Of A Proposal For Reliable Low-Cost Grid Power With 100% Wind, Water, And Solar, Christopher T.M. Clack, Staffan A. Qvist, Jay Apt, Morgan Bazilian, Adam R. Brandt, Ken Caldeira, Steven J. Davis, Victor Diakov, Mark A. Handschy, Paul D.H. Hines, Paulina Jaramillo, Daniel M. Kammen, Jane C.S. Long, M. Granger Morgan, Adam Reed, Varun Sivaram, James Sweeney, George R. Tynan, David G. Victor, John P. Weyant, Jay F. Whitacre

College of Engineering and Mathematical Sciences Faculty Publications

A number of analyses, meta-Analyses, and assessments, including those performed by the Intergovernmental Panel on Climate Change, the National Oceanic and Atmospheric Administration, the National Renewable Energy Laboratory, and the International Energy Agency, have concluded that deployment of a diverse portfolio of clean energy technologies makes a transition to a low-carbon-emission energy system both more feasible and less costly than other pathways. In contrast, Jacobson et al. [Jacobson MZ, Delucchi MA, Cameron MA, Frew BA (2015) Proc Natl Acad Sci USA 112(49):15060-15065] argue that it is feasible to provide "low-cost solutions to the grid reliability problem with 100% penetration of …

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An Automated Approach To Map Winter Cropped Area Of Smallholder Farms Across Large Scales Using Modis Imagery, Meha Jain, Pinki Mondal, Gillian L. Galford, Greg Fiske, Ruth S. Defries Jun 2017

An Automated Approach To Map Winter Cropped Area Of Smallholder Farms Across Large Scales Using Modis Imagery, Meha Jain, Pinki Mondal, Gillian L. Galford, Greg Fiske, Ruth S. Defries

Rubenstein School of Environment and Natural Resources Faculty Publications

Fine-scale agricultural statistics are an important tool for understanding trends in food production and their associated drivers, yet these data are rarely collected in smallholder systems. These statistics are particularly important for smallholder systems given the large amount of fine-scale heterogeneity in production that occurs in these regions. To overcome the lack of ground data, satellite data are often used to map fine-scale agricultural statistics. However, doing so is challenging for smallholder systems because of (1) complex sub-pixel heterogeneity; (2) little to no available calibration data; and (3) high amounts of cloud cover as most smallholder systems occur in the …

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Total And Extreme Precipitation Changes Over The Northeastern United States, Huanping Huang, Jonathan M. Winter, Erich C. Osterberg, Radley M. Horton, Brian Beckage Jun 2017

Total And Extreme Precipitation Changes Over The Northeastern United States, Huanping Huang, Jonathan M. Winter, Erich C. Osterberg, Radley M. Horton, Brian Beckage

College of Agriculture and Life Sciences Faculty Publications

The northeastern United States has experienced a large increase in precipitation over recent decades. Annual and seasonal changes of total and extreme precipitation from station observations in the Northeast were assessed over multiple time periods spanning 1901-2014. Spatially averaged, both annual total and extreme precipitation across the Northeast increased significantly since 1901, with changepoints occurring in 2002 and 1996, respectively. Annual extreme precipitation experienced a larger increase than total precipitation; extreme precipitation from 1996 to 2014 is 53% higher than from 1901 to 1995. Spatially, coastal areas receive more total and extreme precipitation on average, but increases across the changepoints …

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Characterizing Landscape-Scale Erosion Using 10be In Detrital Fluvial Sediment: Slope-Based Sampling Strategy Detects The Effect Of Widespread Dams, Lucas J. Reusser, Paul R. Bierman, Donna M. Rizzo, Eric W. Portenga, Dylan H. Rood May 2017

Characterizing Landscape-Scale Erosion Using 10be In Detrital Fluvial Sediment: Slope-Based Sampling Strategy Detects The Effect Of Widespread Dams, Lucas J. Reusser, Paul R. Bierman, Donna M. Rizzo, Eric W. Portenga, Dylan H. Rood

College of Engineering and Mathematical Sciences Faculty Publications

Concentrations of in situ 10Be measured in detrital fluvial sediment are frequently used to estimate long-term erosion rates of drainage basins. In many regions, basin-averaged erosion rates are positively correlated with basin average slope. The slope dependence of erosion allows model-based erosion rate estimation for unsampled basins and basins where human disturbance may have biased cosmogenic nuclide concentrations in sediment. Using samples collected from southeastern North America, we demonstrate an approach that explicitly considers the relationship between average basin slope and erosion rate. Because dams and reservoirs are ubiquitous on larger channels in the field area, we selected 36 undammed …

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Tropical River Suspended Sediment And Solute Dynamics In Storms During An Extreme Drought, Kathryn E. Clark, James B. Shanley, Martha A. Scholl, Nicolas Perdrial, Julia N. Perdrial, Alain F. Plante, William H. Mcdowell May 2017

Tropical River Suspended Sediment And Solute Dynamics In Storms During An Extreme Drought, Kathryn E. Clark, James B. Shanley, Martha A. Scholl, Nicolas Perdrial, Julia N. Perdrial, Alain F. Plante, William H. Mcdowell

College of Arts and Sciences Faculty Publications

Droughts, which can strongly affect both hydrologic and biogeochemical systems, are projected to become more prevalent in the tropics in the future. We assessed the effects of an extreme drought during 2015 on stream water composition in the Luquillo Mountains of Puerto Rico. We demonstrated that drought base flow in the months leading up to the study was sourced from trade-wind orographic rainfall, suggesting a resistance to the effects of an otherwise extreme drought. In two catchments (Mameyes and Icacos), we sampled a series of four rewetting events that partially alleviated the drought. We collected and analyzed dissolved constituents (major …

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Geochemical Evolution Of The Critical Zone Across Variable Time Scales Informs Concentration-Discharge Relationships: Jemez River Basin Critical Zone Observatory, Jennifer C. Mcintosh, Courtney Schaumberg, Julia Perdrial, Adrian Harpold, Angélica Vázquez-Ortega, Craig Rasmussen, David Vinson, Xavier Zapata-Rios, Paul D. Brooks, Thomas Meixner, Jon Pelletier, Louis Derry, Jon Chorover May 2017

Geochemical Evolution Of The Critical Zone Across Variable Time Scales Informs Concentration-Discharge Relationships: Jemez River Basin Critical Zone Observatory, Jennifer C. Mcintosh, Courtney Schaumberg, Julia Perdrial, Adrian Harpold, Angélica Vázquez-Ortega, Craig Rasmussen, David Vinson, Xavier Zapata-Rios, Paul D. Brooks, Thomas Meixner, Jon Pelletier, Louis Derry, Jon Chorover

College of Arts and Sciences Faculty Publications

This study investigates the influence of water, carbon, and energy fluxes on solute production and transport through the Jemez Critical Zone (CZ) and impacts on C-Q relationships over variable spatial and temporal scales. Chemical depletion-enrichment profiles of soils, combined with regolith thickness and groundwater data indicate the importance to stream hydrochemistry of incongruent dissolution of silicate minerals during deep bedrock weathering, which is primarily limited by water fluxes, in this highly fractured, young volcanic terrain. Under high flow conditions (e.g., spring snowmelt), wetting of soil and regolith surfaces and presence of organic acids promote mineral dissolution and provide a constant …

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Farm Fresh Foods For Healthy Kids (F3hk): An Innovative Community Supported Agriculture Intervention To Prevent Childhood Obesity In Low-Income Families And Strengthen Local Agricultural Economies, Rebecca A. Seguin, Emily H. Morgan, Karla L. Hanson, Alice S. Ammerman, Stephanie B. Jilcott Pitts, Jane Kolodinsky, Marilyn Sitaker, Florence A. Becot, Leah M. Connor, Jennifer A. Garner, Jared T. Mcguirt Apr 2017

Farm Fresh Foods For Healthy Kids (F3hk): An Innovative Community Supported Agriculture Intervention To Prevent Childhood Obesity In Low-Income Families And Strengthen Local Agricultural Economies, Rebecca A. Seguin, Emily H. Morgan, Karla L. Hanson, Alice S. Ammerman, Stephanie B. Jilcott Pitts, Jane Kolodinsky, Marilyn Sitaker, Florence A. Becot, Leah M. Connor, Jennifer A. Garner, Jared T. Mcguirt

College of Agriculture and Life Sciences Faculty Publications

Background: Childhood obesity persists in the United States and is associated with serious health problems. Higher rates of obesity among children from disadvantaged households may be, in part, attributable to disparities in access to healthy foods such as fruits and vegetables. Community supported agriculture can improve access to and consumption of fresh produce, but the upfront payment structure, logistical barriers, and unfamiliarity with produce items may inhibit participation by low-income families. The aim of this project is to assess the impact of subsidized, or "cost-offset," community supported agriculture participation coupled with tailored nutrition education for low-income families with children. Methods/design: …

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