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Full-Text Articles in Physical Sciences and Mathematics

Simulation Of The Effects Of Photodecay On Long-Term Litter Decay Using Daycent, Maosi Chen, William J. Parton, E. Carol Adair, Shinichi Asao, Melannie D. Hartman, Wei Gao Dec 2016

Simulation Of The Effects Of Photodecay On Long-Term Litter Decay Using Daycent, Maosi Chen, William J. Parton, E. Carol Adair, Shinichi Asao, Melannie D. Hartman, Wei Gao

Rubenstein School of Environment and Natural Resources Faculty Publications

Recent studies have found that solar ultraviolet (UV) radiation significantly shifts the mass loss and nitrogen dynamics of plant litter decomposition in semi-arid and arid ecosystems. In this study, we examined the role of photodegradation in litter decomposition by using the DayCent-UV biogeochemical model. DayCent-UV incorporated the following mechanisms related to UV radiation: (1) direct photolysis, (2) facilitation of microbial decomposition via production of labile materials, and (3) microbial inhibition effects. We also allowed maximum photodecay rate of the structural litter pool to vary with litter's initial lignin fraction in the model. We calibrated DayCent-UV with observed ecosystem variables (e.g., …


Reducing Emissions From Agriculture To Meet The 2 °C Target, Eva Wollenberg, Meryl Richards, Pete Smith, Petr Havlík, Michael Obersteiner, Francesco N. Tubiello, Martin Herold, Pierre Gerber, Sarah Carter, Andrew Reisinger, Detlef P. Van Vuuren, Amy Dickie, Henry Neufeldt, Björn O. Sander, Reiner Wassmann, Rolf Sommer, James E. Amonette, Alessandra Falcucci, Mario Herrero, Carolyn Opio, Rosa Maria Roman-Cuesta, Elke Stehfest, Henk Westhoek, Ivan Ortiz-Monasterio, Tek Sapkota, Mariana C. Rufino, Philip K. Thornton, Louis Verchot, Paul C. West, Jean François Soussana, Tobias Baedeker Dec 2016

Reducing Emissions From Agriculture To Meet The 2 °C Target, Eva Wollenberg, Meryl Richards, Pete Smith, Petr Havlík, Michael Obersteiner, Francesco N. Tubiello, Martin Herold, Pierre Gerber, Sarah Carter, Andrew Reisinger, Detlef P. Van Vuuren, Amy Dickie, Henry Neufeldt, Björn O. Sander, Reiner Wassmann, Rolf Sommer, James E. Amonette, Alessandra Falcucci, Mario Herrero, Carolyn Opio, Rosa Maria Roman-Cuesta, Elke Stehfest, Henk Westhoek, Ivan Ortiz-Monasterio, Tek Sapkota, Mariana C. Rufino, Philip K. Thornton, Louis Verchot, Paul C. West, Jean François Soussana, Tobias Baedeker

Rubenstein School of Environment and Natural Resources Faculty Publications

More than 100 countries pledged to reduce agricultural greenhouse gas (GHG) emissions in the 2015 Paris Agreement of the United Nations Framework Convention on Climate Change. Yet technical information about how much mitigation is needed in the sector vs. how much is feasible remains poor. We identify a preliminary global target for reducing emissions from agriculture of ~1 GtCO2e yr−1 by 2030 to limit warming in 2100 to 2 °C above pre-industrial levels. Yet plausible agricultural development pathways with mitigation cobenefits deliver only 21–40% of needed mitigation. The target indicates that more transformative technical and policy options will be needed, …


Coupled Impacts Of Climate And Land Use Change Across A River-Lake Continuum: Insights From An Integrated Assessment Model Of Lake Champlain's Missisquoi Basin, 2000-2040, Asim Zia, Arne Bomblies, Andrew W. Schroth, Christopher Koliba, Peter D.F. Isles, Yushiou Tsai, Ibrahim N. Mohammed, Gabriela Bucini, Patrick J. Clemins, Scott Turnbull, Morgan Rodgers, Ahmed Hamed, Brian Beckage, Jonathan Winter Nov 2016

Coupled Impacts Of Climate And Land Use Change Across A River-Lake Continuum: Insights From An Integrated Assessment Model Of Lake Champlain's Missisquoi Basin, 2000-2040, Asim Zia, Arne Bomblies, Andrew W. Schroth, Christopher Koliba, Peter D.F. Isles, Yushiou Tsai, Ibrahim N. Mohammed, Gabriela Bucini, Patrick J. Clemins, Scott Turnbull, Morgan Rodgers, Ahmed Hamed, Brian Beckage, Jonathan Winter

College of Engineering and Mathematical Sciences Faculty Publications

Global climate change (GCC) is projected to bring higher-intensity precipitation and higher-variability temperature regimes to the Northeastern United States. The interactive effects of GCC with anthropogenic land use and land cover changes (LULCCs) are unknown for watershed level hydrological dynamics and nutrient fluxes to freshwater lakes. Increased nutrient fluxes can promote harmful algal blooms, also exacerbated by warmer water temperatures due to GCC. To address the complex interactions of climate, land and humans, we developed a cascading integrated assessment model to test the impacts of GCC and LULCC on the hydrological regime, water temperature, water quality, bloom duration and severity …


Coupled Impacts Of Climate And Land Use Change Across A River-Lake Continuum: Insights From An Integrated Assessment Model Of Lake Champlain's Missisquoi Basin, 2000-2040, Asim Zia, Arne Bomblies, Andrew W. Schroth, Christopher Koliba, Peter D.F. Isles, Yushiou Tsai, Ibrahim N. Mohammed, Gabriela Bucini, Patrick J. Clemins, Scott Turnbull, Morgan Rodgers, Ahmed Hamed, Brian Beckage, Jonathan Winter, Carol Adair, Gillian L. Galford, Donna Rizzo, Judith Van Houten Nov 2016

Coupled Impacts Of Climate And Land Use Change Across A River-Lake Continuum: Insights From An Integrated Assessment Model Of Lake Champlain's Missisquoi Basin, 2000-2040, Asim Zia, Arne Bomblies, Andrew W. Schroth, Christopher Koliba, Peter D.F. Isles, Yushiou Tsai, Ibrahim N. Mohammed, Gabriela Bucini, Patrick J. Clemins, Scott Turnbull, Morgan Rodgers, Ahmed Hamed, Brian Beckage, Jonathan Winter, Carol Adair, Gillian L. Galford, Donna Rizzo, Judith Van Houten

Rubenstein School of Environment and Natural Resources Faculty Publications

Global climate change (GCC) is projected to bring higher-intensity precipitation and higher-variability temperature regimes to the Northeastern United States. The interactive effects of GCC with anthropogenic land use and land cover changes (LULCCs) are unknown for watershed level hydrological dynamics and nutrient fluxes to freshwater lakes. Increased nutrient fluxes can promote harmful algal blooms, also exacerbated by warmer water temperatures due to GCC. To address the complex interactions of climate, land and humans, we developed a cascading integrated assessment model to test the impacts of GCC and LULCC on the hydrological regime, water temperature, water quality, bloom duration and severity …


Influence Of Topography And Human Activity On Apparent In Situ 10be-Derived Erosion Rates In Yunnan, Sw China, Amanda H. Schmidt, Thomas B. Neilson, Paul R. Bierman, Dylan H. Rood, William B. Ouimet, Veronica Sosa Gonzalez Nov 2016

Influence Of Topography And Human Activity On Apparent In Situ 10be-Derived Erosion Rates In Yunnan, Sw China, Amanda H. Schmidt, Thomas B. Neilson, Paul R. Bierman, Dylan H. Rood, William B. Ouimet, Veronica Sosa Gonzalez

College of Arts and Sciences Faculty Publications

In order to understand better if and where erosion rates calculated using in situ 10Be are affected by contemporary changes in land use and attendant deep regolith erosion, we calculated erosion rates using measurements of in situ 10Be in quartz from 52 samples of river sediment collected from three tributaries of the Mekong River (median basin areaD46.5 km2). Erosion rates range from 12 to 209mm kyr-1 with an area-weighted mean of 117±49mm kyr-1 (1 standard deviation) and median of 74mm kyr-1.We observed a decrease in the relative influence of human activity from our steepest and least altered watershed in the …


A Stochastic Model For Landscape Patterns Of Biodiversity, Jayme A. Prevedello, Nicholas J. Gotelli, Jean Paul Metzger Nov 2016

A Stochastic Model For Landscape Patterns Of Biodiversity, Jayme A. Prevedello, Nicholas J. Gotelli, Jean Paul Metzger

College of Arts and Sciences Faculty Publications

Many factors have been proposed to affect biodiversity patterns across landscapes, including patch area, patch isolation, edge distances, and matrix quality, but existing models emphasize only one or two of these factors at a time. Here we introduce a synthetic but simple individual-based model that generates realistic patterns of species richness and density as a function of landscape structure. In this model, we simulated the stochastic placement of home ranges in landscapes, thus combining features of existing random placement and mid-domain effect models. As such, the model allows investigation of whether and how geometric constraints on home range placement of …


Climatic Warming Destabilizes Forest Ant Communities, Sarah E. Diamond, Lauren M. Nichols, Shannon L. Pelini, Clint A. Penick, Grace W. Barber, Sara Helms Cahan, Robert R. Dunn, Aaron M. Ellison, Nathan J. Sanders, Nicholas J. Gotelli Oct 2016

Climatic Warming Destabilizes Forest Ant Communities, Sarah E. Diamond, Lauren M. Nichols, Shannon L. Pelini, Clint A. Penick, Grace W. Barber, Sara Helms Cahan, Robert R. Dunn, Aaron M. Ellison, Nathan J. Sanders, Nicholas J. Gotelli

College of Arts and Sciences Faculty Publications

How will ecological communities change in response to climate warming? Direct effects of temperature and indirect cascading effects of species interactions are already altering the structure of local communities, but the dynamics of community change are still poorly understood. We explore the cumulative effects of warming on the dynamics and turnover of forest ant communities that were warmed as part of a 5-year climate manipulation experiment at two sites in eastern North America. At the community level, warming consistently increased occupancy of nests and decreased extinction and nest abandonment. This consistency was largely driven by strong responses of a subset …


Variation Of Organic Matter Quantity And Quality In Streams At Critical Zone Observatory Watersheds, Matthew P. Miller, Elizabeth W. Boyer, Diane M. Mcknight, Michael G. Brown, Rachel S. Gabor, Carolyn T. Hunsaker, Lidiia Iavorivska, Shreeram Inamdar, Dale W. Johnson, Louis A. Kaplan, Henry Lin, William H. Mcdowell, Julia N. Perdrial Oct 2016

Variation Of Organic Matter Quantity And Quality In Streams At Critical Zone Observatory Watersheds, Matthew P. Miller, Elizabeth W. Boyer, Diane M. Mcknight, Michael G. Brown, Rachel S. Gabor, Carolyn T. Hunsaker, Lidiia Iavorivska, Shreeram Inamdar, Dale W. Johnson, Louis A. Kaplan, Henry Lin, William H. Mcdowell, Julia N. Perdrial

College of Arts and Sciences Faculty Publications

The quantity and chemical composition of dissolved organic matter (DOM) in surface waters influence ecosystem processes and anthropogenic use of freshwater. However, despite the importance of understanding spatial and temporal patterns in DOM, measures of DOM quality are not routinely included as part of large-scale ecosystem monitoring programs and variations in analytical procedures can introduce artifacts. In this study, we used consistent sampling and analytical methods to meet the objective of defining variability in DOM quantity and quality and other measures of water quality in streamflow issuing from small forested watersheds located within five Critical Zone Observatory sites representing contrasting …


Opportunities For Biodiversity Gains Under The World's Largest Reforestation Programme, Fangyuan Hua, Xiaoyang Wang, Xinlei Zheng, Brendan Fisher, Lin Wang, Jianguo Zhu, Ya Tang, Douglas W. Yu, David S. Wilcove Sep 2016

Opportunities For Biodiversity Gains Under The World's Largest Reforestation Programme, Fangyuan Hua, Xiaoyang Wang, Xinlei Zheng, Brendan Fisher, Lin Wang, Jianguo Zhu, Ya Tang, Douglas W. Yu, David S. Wilcove

Rubenstein School of Environment and Natural Resources Faculty Publications

Reforestation is a critical means of addressing the environmental and social problems of deforestation. China's Grain-for-Green Program (GFGP) is the world's largest reforestation scheme. Here we provide the first nationwide assessment of the tree composition of GFGP forests and the first combined ecological and economic study aimed at understanding GFGP's biodiversity implications. Across China, GFGP forests are overwhelmingly monocultures or compositionally simple mixed forests. Focusing on birds and bees in Sichuan Province, we find that GFGP reforestation results in modest gains (via mixed forest) and losses (via monocultures) of bird diversity, along with major losses of bee diversity. Moreover, all …


Zirconium-Catalyzed Alkene Hydrophosphination And Dehydrocoupling With An Air-Stable, Fluorescent Primary Phosphine, Christine A. Bange, Neil T. Mucha, Morgan E. Cousins, Abigail C. Gehsmann, Anna Singer, Taylor Truax, Lee J. Higham Sep 2016

Zirconium-Catalyzed Alkene Hydrophosphination And Dehydrocoupling With An Air-Stable, Fluorescent Primary Phosphine, Christine A. Bange, Neil T. Mucha, Morgan E. Cousins, Abigail C. Gehsmann, Anna Singer, Taylor Truax, Lee J. Higham

College of Arts and Sciences Faculty Publications

Zirconium-catalyzed alkene hydrophosphination and dehydrocoupling with an air-stable, fluorescent primary phosphine 8-[(4-phosphino)phenyl]-4,4-dimethyl-1,3,5,7-tetramethyl-2,6-diethyl- 4-bora-3a,4a-diaza-s-indacene furnishes fluorescent phosphine products. Hydrophosphination of the fluorescent phosphine produces products with a complete selectivity for the secondary product. A key intermediate in catalysis, a zirconium phosphido compound, was isolated.


Limited Role Of Character Displacement In The Coexistence Of Congeneric Anelosimus Spiders In A Madagascan Montane Forest, Ingi Agnarsson, Nicholas J. Gotelli, Diego Agostini, Matjaž Kuntner Aug 2016

Limited Role Of Character Displacement In The Coexistence Of Congeneric Anelosimus Spiders In A Madagascan Montane Forest, Ingi Agnarsson, Nicholas J. Gotelli, Diego Agostini, Matjaž Kuntner

College of Arts and Sciences Faculty Publications

Evolutionary and ecological theory predicts that closely related and similar species should coexist infrequently because speciation is more likely to occur allopatrically than sympatrically, and because co-occurring species with similar traits may compete for limited resources, leading to competitive exclusion or character displacement. Here we study the unusual coexistence of 10 similar congeneric species of Anelosimus spiders within a small forest fragment in Madagascar. We asked if these species radiated in sympatry or allopatry, and if there was evidence for local-scale character displacement in body size and other species-level traits. We sampled ∼ 350 colonies (6346 individuals) along a 2800 …


Changing Forests-Changing Streams: Riparian Forest Stand Development And Ecosystem Function In Temperate Headwaters, Dana R. Warren, William S. Keeton, Peter M. Kiffney, Matthew J. Kaylor, Heather A. Bechtold, John Magee Aug 2016

Changing Forests-Changing Streams: Riparian Forest Stand Development And Ecosystem Function In Temperate Headwaters, Dana R. Warren, William S. Keeton, Peter M. Kiffney, Matthew J. Kaylor, Heather A. Bechtold, John Magee

Rubenstein School of Environment and Natural Resources Faculty Publications

Light availability influences temperature, primary production, nutrient dynamics, and secondary production in aquatic ecosystems. In forested freshwater ecosystems, shading by streamside (riparian) vegetation is a dominant control on light flux and represents an important interaction at the aquatic-terrestrial interface. Changes in forest structure over time, particularly tree mortality processes that gradually increase light penetration through maturing forest canopies, are likely to influence stream light fluxes and associated ecosystem functions. We provide a set of conceptual models describing how stream light dynamics change with the development of complex canopy structure and how changes in light availability are likely to affect stream …


Pyrogenic Fuels Produced By Savanna Trees Can Engineer Humid Savannas, William J. Platt, Darin P. Ellair, Jean M. Huffman, Stephen E. Potts, Brian Beckage Aug 2016

Pyrogenic Fuels Produced By Savanna Trees Can Engineer Humid Savannas, William J. Platt, Darin P. Ellair, Jean M. Huffman, Stephen E. Potts, Brian Beckage

College of Agriculture and Life Sciences Faculty Publications

Natural fires ignited by lightning strikes following droughts frequently are posited as the ecological mechanism maintaining discontinuous tree cover and grass-dominated ground layers in savannas. Such fires, however, may not reliably maintain humid savannas. We propose that savanna trees producing pyrogenic shed leaves might engineer fire characteristics, affecting ground-layer plants in ways that maintain humid savannas. We explored our hypothesis in a high-rainfall, frequently burned pine savanna in which the dominant tree, longleaf pine (Pinus palustris), produces resinous needles that become highly flammable when shed and dried. We postulated that pyrogenic needles should have much greater influence on fire characteristics …


Farmer Perceptions Of Climate Change: Associations With Observed Temperature And Precipitation Trends, Irrigation, And Climate Beliefs, Meredith T. Niles, Nathaniel D. Mueller Jul 2016

Farmer Perceptions Of Climate Change: Associations With Observed Temperature And Precipitation Trends, Irrigation, And Climate Beliefs, Meredith T. Niles, Nathaniel D. Mueller

College of Agriculture and Life Sciences Faculty Publications

How individuals perceive climate change is linked to whether individuals support climate policies and whether they alter their own climate-related behaviors, yet climate perceptions may be influenced by many factors beyond local shifts in weather. Infrastructure designed to control or regulate natural resources may serve as an important lens through which people experience climate, and thus may influence perceptions. Likewise, perceptions may be influenced by personal beliefs about climate change and whether it is human-induced. Here we examine farmer perceptions of historical climate change, how perceptions are related to observed trends in regional climate, how perceptions are related to the …


Endangered Right Whales Enhance Primary Productivity In The Bay Of Fundy, Joe Roman, John Nevins, Mark Altabet, Heather Koopman, James Mccarthy Jun 2016

Endangered Right Whales Enhance Primary Productivity In The Bay Of Fundy, Joe Roman, John Nevins, Mark Altabet, Heather Koopman, James Mccarthy

Rubenstein School of Environment and Natural Resources Faculty Publications

This is an open access article distributed under the terms of the Creative Commons Attribution License, which permits unrestricted use, distribution, and reproduction in any medium, provided the original author and source are credited. Marine mammals have recently been documented as important facilitators of rapid and efficient nutrient recycling in coastal and offshore waters. Whales enhance phytoplankton nutrition by releasing fecal plumes near the surface after feeding and by migrating from highly productive, high-latitude feeding areas to low-latitude nutrient-poor calving areas. In this study, we measured NH4 + and PO4 3- release rates from the feces of North Atlantic right …


Surface Permeability Of Natural And Engineered Porous Building Materials, David Grover, Cabot R. Savidge, Laura Townsend, Odanis Rosario, Liang Bo Hu, Donna M. Rizzo, Mandar M. Dewoolkar Jun 2016

Surface Permeability Of Natural And Engineered Porous Building Materials, David Grover, Cabot R. Savidge, Laura Townsend, Odanis Rosario, Liang Bo Hu, Donna M. Rizzo, Mandar M. Dewoolkar

College of Engineering and Mathematical Sciences Faculty Publications

Characterization of surface gas permeability measurements on a variety of natural and engineered building materials using two relatively new, non-destructive surface permeameters is presented. Surface gas permeability measurements were consistent for both laboratory and field applications and correlated well with bulk gas permeability measurements. This research indicates that surface permeability measurements could provide reliable estimates of bulk gas permeability; and due to the non-destructive nature and relative sampling ease of both surface gas permeability tools, it is possible to quantify the range of the spatial autocorrelation, heterogeneity, and anisotropy in porous building materials and their degree of degradation from weathering.


Limits Of Agricultural Greenhouse Gas Calculators To Predict Soil N2O And Ch4 Fluxes In Tropical Agriculture, Meryl Richards, Ruth Metzel, Ngonidzashe Chirinda, Proyuth Ly, George Nyamadzawo, Quynh Duong Vu, Andreas De Neergaard, Myles Oelofse, Eva Wollenberg, Emma Keller, Daniella Malin, Jørgen E. Olesen, Jonathan Hillier, Todd S. Rosenstock May 2016

Limits Of Agricultural Greenhouse Gas Calculators To Predict Soil N2O And Ch4 Fluxes In Tropical Agriculture, Meryl Richards, Ruth Metzel, Ngonidzashe Chirinda, Proyuth Ly, George Nyamadzawo, Quynh Duong Vu, Andreas De Neergaard, Myles Oelofse, Eva Wollenberg, Emma Keller, Daniella Malin, Jørgen E. Olesen, Jonathan Hillier, Todd S. Rosenstock

Rubenstein School of Environment and Natural Resources Faculty Publications

Demand for tools to rapidly assess greenhouse gas impacts from policy and technological change in the agricultural sector has catalyzed the development of ' GHG calculators'-simple accounting approaches that use a mix of emission factors and empirical models to calculate GHG emissions with minimal input data. GHG calculators, however, rely on models calibrated from measurements conducted overwhelmingly under temperate, developed country conditions. Here we show that GHG calculators may poorly estimate emissions in tropical developing countries by comparing calculator predictions against measurements from Africa, Asia, and Latin America. Estimates based on GHG calculators were greater than measurements in 70% of …


Tracking Climate Change Through The Spatiotemporal Dynamics Of The Teletherms, The Statistically Hottest And Coldest Days Of The Year, Peter Sheridan Dodds, Lewis Mitchell, Andrew J. Reagan, Christopher M. Danforth May 2016

Tracking Climate Change Through The Spatiotemporal Dynamics Of The Teletherms, The Statistically Hottest And Coldest Days Of The Year, Peter Sheridan Dodds, Lewis Mitchell, Andrew J. Reagan, Christopher M. Danforth

College of Engineering and Mathematical Sciences Faculty Publications

Instabilities and long term shifts in seasons, whether induced by natural drivers or human activities, pose great disruptive threats to ecological, agricultural, and social systems. Here, we propose, measure, and explore two fundamental markers of location-sensitive seasonal variations: the Summer and Winter Teletherms - the on-average annual dates of the hottest and coldest days of the year. We analyse daily temperature extremes recorded at 1218 stations across the contiguous United States from 1853-2012, and observe large regional variation with the Summer Teletherm falling up to 90 days after the Summer Solstice, and 50 days for the Winter Teletherm after the …


Species Interactions And Random Dispersal Rather Than Habitat Filtering Drive Community Assembly During Early Plant Succession, Werner Ulrich, Markus Klemens Zaplata, Susanne Winter, Wolfgang Schaaf, Anton Fischer, Santiago Soliveres, Nicholas J. Gotelli May 2016

Species Interactions And Random Dispersal Rather Than Habitat Filtering Drive Community Assembly During Early Plant Succession, Werner Ulrich, Markus Klemens Zaplata, Susanne Winter, Wolfgang Schaaf, Anton Fischer, Santiago Soliveres, Nicholas J. Gotelli

College of Arts and Sciences Faculty Publications

Theory on plant succession predicts a temporal increase in the complexity of spatial community structure and of competitive interactions: initially random occurrences of early colonising species shift towards spatially and competitively structured plant associations in later successional stages. Here we use long-term data on early plant succession in a German post mining area to disentangle the importance of random colonisation, habitat filtering, and competition on the temporal and spatial development of plant community structure. We used species co-occurrence analysis and a recently developed method for assessing competitive strength and hierarchies (transitive versus intransitive competitive orders) in multispecies communities. We found …


Do Insect Outbreaks Reduce The Severity Of Subsequent Forest Fires?, Garrett W. Meigs, Harold S.J. Zald, John L. Campbell, William S. Keeton, Robert E. Kennedy Apr 2016

Do Insect Outbreaks Reduce The Severity Of Subsequent Forest Fires?, Garrett W. Meigs, Harold S.J. Zald, John L. Campbell, William S. Keeton, Robert E. Kennedy

Rubenstein School of Environment and Natural Resources Faculty Publications

Understanding the causes and consequences of rapid environmental change is an essential scientific frontier, particularly given the threat of climate- and land use-induced changes in disturbance regimes. In western North America, recent widespread insect outbreaks and wildfires have sparked acute concerns about potential insect-fire interactions. Although previous research shows that insect activity typically does not increase wildfire likelihood, key uncertainties remain regarding insect effects on wildfire severity (i.e., ecological impact). Recent assessments indicate that outbreak severity and burn severity are not strongly associated, but these studies have been limited to specific insect or fire events. Here, we present a regional …


Thermal Reactionomes Reveal Divergent Responses To Thermal Extremes In Warm And Cool-Climate Ant Species, John Stanton-Geddes, Andrew Nguyen, Lacy Chick, James Vincent, Mahesh Vangala, Robert R. Dunn, Aaron M. Ellison, Nathan J. Sanders, Nicholas J. Gotelli, Sara Helms Cahan Mar 2016

Thermal Reactionomes Reveal Divergent Responses To Thermal Extremes In Warm And Cool-Climate Ant Species, John Stanton-Geddes, Andrew Nguyen, Lacy Chick, James Vincent, Mahesh Vangala, Robert R. Dunn, Aaron M. Ellison, Nathan J. Sanders, Nicholas J. Gotelli, Sara Helms Cahan

College of Arts and Sciences Faculty Publications

Background: The distributions of species and their responses to climate change are in part determined by their thermal tolerances. However, little is known about how thermal tolerance evolves. To test whether evolutionary extension of thermal limits is accomplished through enhanced cellular stress response (enhanced response), constitutively elevated expression of protective genes (genetic assimilation) or a shift from damage resistance to passive mechanisms of thermal stability (tolerance), we conducted an analysis of the reactionome: the reaction norm for all genes in an organism's transcriptome measured across an experimental gradient. We characterized thermal reactionomes of two common ant species in the eastern …


The Moral Basis For Conservation - Reflections On Dickman Et Al., Douglas Sheil, Jane Cohen, Carol J.Pierce Colfer, David Price, Rajindra Puri, Manuel Ruiz-Perez, Yulia Sugandi, Paul Vedeld, Eva Wollenberg, Yurdi Yasmi Mar 2016

The Moral Basis For Conservation - Reflections On Dickman Et Al., Douglas Sheil, Jane Cohen, Carol J.Pierce Colfer, David Price, Rajindra Puri, Manuel Ruiz-Perez, Yulia Sugandi, Paul Vedeld, Eva Wollenberg, Yurdi Yasmi

Rubenstein School of Environment and Natural Resources Faculty Publications

No abstract provided.


Predicting Flow Reversals In A Computational Fluid Dynamics Simulated Thermosyphon Using Data Assimilation, Andrew J. Reagan, Yves Dubief, Peter Sheridan Dodds, Christopher M. Danforth Feb 2016

Predicting Flow Reversals In A Computational Fluid Dynamics Simulated Thermosyphon Using Data Assimilation, Andrew J. Reagan, Yves Dubief, Peter Sheridan Dodds, Christopher M. Danforth

College of Engineering and Mathematical Sciences Faculty Publications

A thermal convection loop is a annular chamber filled with water, heated on the bottom half and cooled on the top half. With sufficiently large forcing of heat, the direction of fluid flow in the loop oscillates chaotically, dynamics analogous to the Earth's weather. As is the case for state-of-the-art weather models, we only observe the statistics over a small region of state space, making prediction difficult. To overcome this challenge, data assimilation (DA) methods, and specifically ensemble methods, use the computational model itself to estimate the uncertainty of the model to optimally combine these observations into an initial condition …


The Evolution Of Heat Shock Protein Sequences, Cis-Regulatory Elements, And Expression Profiles In The Eusocial Hymenoptera, Andrew D. Nguyen, Nicholas J. Gotelli, Sara Helms Cahan Jan 2016

The Evolution Of Heat Shock Protein Sequences, Cis-Regulatory Elements, And Expression Profiles In The Eusocial Hymenoptera, Andrew D. Nguyen, Nicholas J. Gotelli, Sara Helms Cahan

College of Arts and Sciences Faculty Publications

Background: The eusocial Hymenoptera have radiated across a wide range of thermal environments, exposing them to significant physiological stressors. We reconstructed the evolutionary history of three families of Heat Shock Proteins (Hsp90, Hsp70, Hsp40), the primary molecular chaperones protecting against thermal damage, across 12 Hymenopteran species and four other insect orders. We also predicted and tested for thermal inducibility of eight Hsps from the presence of cis-regulatory heat shock elements (HSEs). We tested whether Hsp induction patterns in ants were associated with different thermal environments. Results: We found evidence for duplications, losses, and cis-regulatory changes in two of the three …


Dating The Incision Of The Yangtze River Gorge At The First Bend Using Three-Nuclide Burial Ages, Devin Mcphillips, Gregory D. Hoke, Jing Liu-Zeng, Paul R. Bierman, Dylan H. Rood, Samuel Niedermann Jan 2016

Dating The Incision Of The Yangtze River Gorge At The First Bend Using Three-Nuclide Burial Ages, Devin Mcphillips, Gregory D. Hoke, Jing Liu-Zeng, Paul R. Bierman, Dylan H. Rood, Samuel Niedermann

College of Arts and Sciences Faculty Publications

Incision of the Yangtze River gorge is widely interpreted as evidence for lower crustal flow beneath the southeast margin of the Tibetan Plateau. Previous work focused on the onset of incision, but the duration of incision remains unknown. Here we present cosmogenic nuclide burial ages of sediments collected from caves on the walls of the gorge that show the gorge was incised ~1 km sometime between 18 and 9 Ma. Thereafter, incision slowed substantially. We resolve middle Miocene burial ages by using three nuclides and accounting for in situ muogenic production. This approach explains the absolute concentrations of 10Be, 26Al, …


Farmer Perceptions Of Climate Change Risk And Associated On-Farm Management Strategies In Vermont, Northeastern United States, Rachel E. Schattman, David Conner, V. Ernesto Méndez Jan 2016

Farmer Perceptions Of Climate Change Risk And Associated On-Farm Management Strategies In Vermont, Northeastern United States, Rachel E. Schattman, David Conner, V. Ernesto Méndez

College of Agriculture and Life Sciences Faculty Publications

Little research has been conducted on how agricultural producers in the northeastern United States conceptualize climate-related risk and how these farmers address risk through on-farm management strategies. Two years following Tropical Storm Irene, our team interviewed 15 farmers in order to investigate their perceptions of climate-related risk and how their decision-making was influenced by these perceptions. Our results show that Vermont farmers are concerned with both ecological and economic risk. Subthemes that emerged included geographic, topographic, and hydrological characteristics of farm sites; stability of land tenure; hydrological erosion; pest and disease pressure; market access; household financial stability; and floods. Farmers …


Triamidoamine-Supported Zirconium: Hydrogen Activation, Lewis Acidity, And: Rac -Lactide Polymerization, Sarah E. Leshinski, Craig A. Wheaton, Hongsui Sun, Andrew J. Roering, Joseph M. Tanski, Daniel J. Fox, Paul G. Hayes Jan 2016

Triamidoamine-Supported Zirconium: Hydrogen Activation, Lewis Acidity, And: Rac -Lactide Polymerization, Sarah E. Leshinski, Craig A. Wheaton, Hongsui Sun, Andrew J. Roering, Joseph M. Tanski, Daniel J. Fox, Paul G. Hayes

College of Arts and Sciences Faculty Publications

Investigation of a triamidoamine-supported zirconium hydride intermediate, important to a range of catalytic reactions, revealed the potential Lewis acidity of [κ5-N,N,N,N,C-(Me3SiNCH2CH2)2NCH2CH2NSiMe2CH2]Zr (1). A preliminary study of 1 as a precursor for the polymerization of rac-lactide showed modest activity but indicated that five-coordinate zirconium complexes with tetra-N donor ligands may be an avenue for further development in group 4 metal lactide polymerization catalysis.


The Role Of Green Leafy Plants In Atmospheric Chemistry: Volatile Emissions And Secondary Organic Aerosol, Rebecca Harvey Jan 2016

The Role Of Green Leafy Plants In Atmospheric Chemistry: Volatile Emissions And Secondary Organic Aerosol, Rebecca Harvey

Graduate College Dissertations and Theses

Aerosols play important roles in atmospheric and environmental processes. Not only do they impact human health, they also affect visibility and climate. Despite recent advances made to under their sources and fate, there remains a limited understanding of the mechanisms that lead to the formation of aerosols and their ultimate fate in the atmosphere. These knowledge gaps provide the crux of the research reported herein, which has focused on identifying novel sources of atmospheric aerosol, characterizing its physical and optical properties, and rationalizing these properties using an in-depth knowledge of the molecular level mechanisms that led to its formation.

Upon …


Development And Evaluation Of High-Resolution Climate Simulations Over The Mountainous Northeastern United States, Jonathan M. Winter, Brian Beckage, Gabriela Bucini, Radley M. Horton, Patrick J. Clemins Jan 2016

Development And Evaluation Of High-Resolution Climate Simulations Over The Mountainous Northeastern United States, Jonathan M. Winter, Brian Beckage, Gabriela Bucini, Radley M. Horton, Patrick J. Clemins

College of Agriculture and Life Sciences Faculty Publications

The mountain regions of the northeastern United States are a critical socioeconomic resource for Vermont, New York State, New Hampshire, Maine, and southern Quebec. While global climate models (GCMs) are important tools for climate change risk assessment at regional scales, even the increased spatial resolution of statistically downscaled GCMs (commonly ~1/8°) is not sufficient for hydrologic, ecologic, and land-use modeling of small watersheds within the mountainous Northeast. To address this limitation, an ensemble of topographically downscaled, high-resolution (30"), daily 2-m maximum air temperature; 2-m minimum air temperature; and precipitation simulations are developed for the mountainous Northeast by applying an additional …


The Impacts Of Climate Change On Precipitation And Hydrology In The Northeastern United States, Justin Guilbert Jan 2016

The Impacts Of Climate Change On Precipitation And Hydrology In The Northeastern United States, Justin Guilbert

Graduate College Dissertations and Theses

Shifting climatic regimes can increase or decrease the frequency of extreme hydrologic events (e.g., high and low streamflows) causing large societal and environmental impacts. The impacts are numerous and include human health and safety, the destruction of infrastructure, water resources, nutrient and sediment transport, and within stream ecological health. It is unclear how the hydrology of a given region will shift in response to climate change. This is especially the case in areas that are seasonally snow covered as the interplay of changing temperature, precipitation, and resulting snowpack can lead to an increased risk of flood or drought.

This research …