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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 …


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.


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 …


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 …


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 …


The Use Of Extrafloral Nectar In Pest Management: Overcoming Context Dependence, Ian Matthew Jones, Suzanne Koptur, Eric J. Von Wettberg Apr 2017

The Use Of Extrafloral Nectar In Pest Management: Overcoming Context Dependence, Ian Matthew Jones, Suzanne Koptur, Eric J. Von Wettberg

College of Agriculture and Life Sciences Faculty Publications

Extrafloral nectar (EFN) provides plants with indirect defence against herbivores by attracting predatory insects, predominantly ants. Decades of research have supported the role of EFN as an effective plant defence, dating back to Thomas Belt's description of ants on acacia in 1874. Despite this extensive body of literature, knowledge of the ecological role of EFN has rarely been applied in the field of pest management. We review the existing literature on the use of EFN in agriculture and consider the obstacles that have hindered this transition. Chief among these obstacles is the influence of ecological context on the outcome of …


Effect Of Drive Row Ground Covers On Hop (Rosales: Cannabaceae) Yard Arthropod Pests In Vermont, Usa, L. Calderwood, J. Cubins, D. Vesty, H. Darby Apr 2017

Effect Of Drive Row Ground Covers On Hop (Rosales: Cannabaceae) Yard Arthropod Pests In Vermont, Usa, L. Calderwood, J. Cubins, D. Vesty, H. Darby

College of Agriculture and Life Sciences Faculty Publications

Alternatives to pesticides are necessary for the management of hop (Humulus lupulus L.) arthropod pests. The three major arthropod pests in northeastern US hop production include two-spotted spider mite, Tetranychus urticae Koch, hop aphid Phorodon humuli (Schrank), and potato leafhopper, Empoasca fabae Harris. This 3-yr study (2012-2014) in Vermont investigated the effect of flowering ground covers on arthropod pest abundance. Hop cultivars 'Nugget' and 'Cascade' were evaluated under a strip-split plot experimental design. Ground cover treatments included 1) Control: mowed red clover (Trifolium pratense) and resident weeds, 2) Clover: red clover, and 3) Diverse: common yarrow (Achillea millefolium), beebalm (Monarda …


Policies For Reintegrating Crop And Livestock Systems: A Comparative Analysis, Rachael D. Garrett, Meredith Niles, Juliana Gil, Philip Dy, Julio Reis, Judson Valentim Mar 2017

Policies For Reintegrating Crop And Livestock Systems: A Comparative Analysis, Rachael D. Garrett, Meredith Niles, Juliana Gil, Philip Dy, Julio Reis, Judson Valentim

College of Agriculture and Life Sciences Faculty Publications

The reintegration of crop and livestock systems within the same land area has the potential to improve soil quality and reduce water and air pollution, while maintaining high yields and reducing risk. In this study, we characterize the degree to which federal policies in three major global food production regions that span a range of socioeconomic contexts, Brazil, New Zealand, and the United States, incentivize or disincentivize the use of integrated crop and livestock practices (ICLS). Our analysis indicates that Brazil and New Zealand have the most favorable policy environment for ICLS, while the United States provides the least favorable …


Integrating Fisheries And Agricultural Programs For Food Security, Brendan Fisher, Robin Naidoo, John Guernier, Kiersten Johnson, Daniel Mullins, Dorcas Robinson, Edward H. Allison Jan 2017

Integrating Fisheries And Agricultural Programs For Food Security, Brendan Fisher, Robin Naidoo, John Guernier, Kiersten Johnson, Daniel Mullins, Dorcas Robinson, Edward H. Allison

Rubenstein School of Environment and Natural Resources Faculty Publications

Background: Despite the connections between terrestrial and marine/freshwater livelihood strategies that we see in coastal regions across the world, the contribution of wild fisheries and fish farming is seldom considered in analyses of the global food system and is consequently underrepresented in major food security and nutrition policy initiatives. Understanding the degree to which farmers also consume fish, and how fishers also grow crops, would help to inform more resilient food security interventions. Results: By compiling a dataset for 123,730 households across 6781 sampling clusters in 12 highly food-insecure countries, we find that between 10 and 45% of the population …


Reducing Greenhouse Gas Emissions In Agriculture Without Compromising Food Security?, Stefan Frank, Petr Havlík, Jean François Soussana, Antoine Levesque, Hugo Valin, Eva Wollenberg, Ulrich Kleinwechter, Oliver Fricko, Mykola Gusti, Mario Herrero, Pete Smith, Tomoko Hasegawa, Florian Kraxner, Michael Obersteiner Jan 2017

Reducing Greenhouse Gas Emissions In Agriculture Without Compromising Food Security?, Stefan Frank, Petr Havlík, Jean François Soussana, Antoine Levesque, Hugo Valin, Eva Wollenberg, Ulrich Kleinwechter, Oliver Fricko, Mykola Gusti, Mario Herrero, Pete Smith, Tomoko Hasegawa, Florian Kraxner, Michael Obersteiner

Rubenstein School of Environment and Natural Resources Faculty Publications

To keep global warming possibly below 1.5◦C and mitigate adverse effects of climate change, agriculture, like all other sectors, will have to contribute to efforts in achieving net negative emissions by the end of the century. Cost-efficient distribution of mitigation across regions and economic sectors is typically calculated using a global uniform carbon price in climate stabilization scenarios. However, in reality such a carbon price would substantially affect food availability. Here, we assess the implications of climate change mitigation in the land use sector for agricultural production and food security using an integrated partial equilibrium modelling framework and explore ways …


Challenges Facing Gap-Based Silviculture And Possible Solutions For Mesic Northern Forests In North America, Christel C. Kern, Julia I. Burton, Patricia Raymond, Anthony W. D'Amato, William S. Keeton, Alejandro A. Royo, Michael B. Walters, Christopher R. Webster, John L. Willis Jan 2017

Challenges Facing Gap-Based Silviculture And Possible Solutions For Mesic Northern Forests In North America, Christel C. Kern, Julia I. Burton, Patricia Raymond, Anthony W. D'Amato, William S. Keeton, Alejandro A. Royo, Michael B. Walters, Christopher R. Webster, John L. Willis

Rubenstein School of Environment and Natural Resources Faculty Publications

Gap-based silvicultural systems were developed under the assumption that richness, and diversity of tree species and other biota positively respond to variation in size of harvest-created canopy gaps. However, varying gap size alone often does not meet diversity objectives and broader goals to address contemporary forest conditions. Recent research highlights the need to consider site factors and history, natural disturbance models, within-gap structure and recruitment requirements in addition to light resources for desired tree diversity. This synthesis brings together silvicultural developments and ecological literature on gap-based management, highlighting interactions with other factors such as microsite conditions, non-tree vegetation and more. …


Integrating Agroecology And Participatory Action Research (Par): Lessons From Central America, V. Ernesto Méndez, Martha Caswell, Stephen R. Gliessman, Roseann Cohen Jan 2017

Integrating Agroecology And Participatory Action Research (Par): Lessons From Central America, V. Ernesto Méndez, Martha Caswell, Stephen R. Gliessman, Roseann Cohen

College of Agriculture and Life Sciences Faculty Publications

The last decade has seen an increasing advancement and interest in the integration of agroecology and participatory action research (PAR). This article aims to: (1) analyze the key characteristics and principles of two case studies that integrated PAR and agroecology in Central America; and (2) learn from the lessons offered by these case studies, as well as others from the literature, on how to better integrate PAR and agroecology. Key principles identified for effective PAR agroecological processes include a shared interest in research by partners, a belief in collective power/action, a commitment to participation, practicing humility and establishing trust and …


Harnessing Local Strength For Sustainable Coffee Value Chains In India And Nicaragua: Reevaluating Certification To Global Sustainability Standards, Dagmar Mithöfer, V. Ernesto Méndez, Arshiya Bose, Philippe Vaast Jan 2017

Harnessing Local Strength For Sustainable Coffee Value Chains In India And Nicaragua: Reevaluating Certification To Global Sustainability Standards, Dagmar Mithöfer, V. Ernesto Méndez, Arshiya Bose, Philippe Vaast

College of Agriculture and Life Sciences Faculty Publications

Coffee is generally grown in areas derived from forest, and both its expansion and management cause biodiversity loss. Sustainability standards in coffee are well established but have been criticized while social and environmental impact is elusive. This paper assesses the issue-attention cycle of coffee production in India and Nicaragua, including producer concerns and responses over time to concerns (sustainability standards, public regulations and development projects). Systematic comparison of the socioeconomic, environmental and policy context in both countries is then used to explore potential effects of sustainability standards. Results show limits, in local context, to relevance of global certification approaches: in …