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Full-Text Articles in Physical Sciences and Mathematics

Core Handling, Transportation And Processing For The South Pole Ice Core (Spicecore) Project, Joseph M. Souney, Mark S. Twickler, Murat Aydin, Eric J. Steig, T.J. Fudge, Leah V. Street, Melinda R. Nicewonger, Emma C. Kahle, Jay A. Johnson, Tanner W. Kuhl, Kimberly A. Casey, John M. Fegyveresi, Richard M. Nunn, Geoffrey M. Hargreaves Dec 2020

Core Handling, Transportation And Processing For The South Pole Ice Core (Spicecore) Project, Joseph M. Souney, Mark S. Twickler, Murat Aydin, Eric J. Steig, T.J. Fudge, Leah V. Street, Melinda R. Nicewonger, Emma C. Kahle, Jay A. Johnson, Tanner W. Kuhl, Kimberly A. Casey, John M. Fegyveresi, Richard M. Nunn, Geoffrey M. Hargreaves

Earth Systems Research Center

An intermediate-depth (1751 m) ice core was drilled at the South Pole between 2014 and 2016 using the newly designed US Intermediate Depth Drill. The South Pole ice core is the highest-resolution interior East Antarctic ice core record that extends into the glacial period. The methods used at the South Pole to handle and log the drilled ice, the procedures used to safely retrograde the ice back to the National Science Foundation Ice Core Facility (NSF-ICF), and the methods used to process and sample the ice at the NSF-ICF are described. The South Pole ice core exhibited minimal brittle ice, …


Assessing Microbial Residues In Soil As A Potential Carbon Sink And Moderator Of Carbon Use Efficiency, Kevin M. Geyer, Jorg Schnecker, A. Stuart Grandy, Andreas Richter, Serita D. Frey Nov 2020

Assessing Microbial Residues In Soil As A Potential Carbon Sink And Moderator Of Carbon Use Efficiency, Kevin M. Geyer, Jorg Schnecker, A. Stuart Grandy, Andreas Richter, Serita D. Frey

Faculty Publications

A longstanding assumption of glucose tracing experiments is that all glucose is microbially utilized during short incubations of ≤2 days to become microbial biomass or carbon dioxide. Carbon use efficiency (CUE) estimates have consequently ignored the formation of residues (non-living microbial products) although such materials could represent an important sink of glucose that is prone to stabilization as soil organic matter. We examined the dynamics of microbial residue formation from a short tracer experiment with frequent samplings over 72 h, and conducted a meta-analysis of previously published glucose tracing studies to assess the generality of these experimental results. Both our …


The Transition From Stochastic To Deterministic Bacterial Community Assembly During Permafrost Thaw Succession, Stacey J. Doherty, Robyn A. Barbato, A. Stuart Grandy, W. Kelley Thomas, Sylvain Monteux, Ellen Dorrepaal, Margareta Johansson, Jessica G. Ernakovich Nov 2020

The Transition From Stochastic To Deterministic Bacterial Community Assembly During Permafrost Thaw Succession, Stacey J. Doherty, Robyn A. Barbato, A. Stuart Grandy, W. Kelley Thomas, Sylvain Monteux, Ellen Dorrepaal, Margareta Johansson, Jessica G. Ernakovich

Faculty Publications

The Northern high latitudes are warming twice as fast as the global average, and permafrost has become vulnerable to thaw. Changes to the environment during thaw leads to shifts in microbial communities and their associated functions, such as greenhouse gas emissions. Understanding the ecological processes that structure the identity and abundance (i.e., assembly) of pre- and post-thaw communities may improve predictions of the functional outcomes of permafrost thaw. We characterized microbial community assembly during permafrost thaw using in situ observations and a laboratory incubation of soils from the Storflaket Mire in Abisko, Sweden, where permafrost thaw has occurred over the …


Fungal Community Structure And Function Shifts With Atmospheric Nitrogen Deposition, Jessica A. M. Moore, Mark A. Anthony, Gregory J. Pec, Lidia K. Trocha, Artur Trzebny, Kevin M. Geyer, Linda T. A. Van Diepen, Serita D. Frey Nov 2020

Fungal Community Structure And Function Shifts With Atmospheric Nitrogen Deposition, Jessica A. M. Moore, Mark A. Anthony, Gregory J. Pec, Lidia K. Trocha, Artur Trzebny, Kevin M. Geyer, Linda T. A. Van Diepen, Serita D. Frey

Faculty Publications

Fungal decomposition of soil organic matter depends on soil nitrogen (N) availability. This ecosystem process is being jeopardized by changes in N inputs that have resulted from a tripling of atmospheric N deposition in the last century. Soil fungi are impacted by atmospheric N deposition due to higher N availability, as soils are acidified, or as micronutrients become increasingly limiting. Fungal communities that persist with chronic N deposition may be enriched with traits that enable them to tolerate environmental stress, which may trade-off with traits enabling organic matter decomposition. We hypothesized that fungal communities would respond to N deposition by …


Plant Invasion Impacts On Fungal Community Structure And Function Depend On Soil Warming And Nitrogen Enrichment, Mark A. Anthony, K. A. Stinson, Jessica A. M. Moore, Serita D. Frey Nov 2020

Plant Invasion Impacts On Fungal Community Structure And Function Depend On Soil Warming And Nitrogen Enrichment, Mark A. Anthony, K. A. Stinson, Jessica A. M. Moore, Serita D. Frey

Faculty Publications

The impacts of invasive species on biodiversity may be mitigated or exacerbated by abiotic environmental changes. Invasive plants can restructure soil fungal communities with important implications for native biodiversity and nutrient cycling, yet fungal responses to invasion may depend on numerous anthropogenic stressors. In this study, we experimentally invaded a long-term soil warming and simulated nitrogen deposition experiment with the widespread invasive plant Alliaria petiolata (garlic mustard) and tested the responses of soil fungal communities to invasion, abiotic factors, and their interaction. We focused on the phytotoxic garlic mustard because it suppresses native mycorrhizae across forests of North America. We …


Stoichiometrically Coupled Carbon And Nitrogen Cycling In The Microbial-Mineral Carbon Stabilization Model Version 1.0 (Mimics-Cn V1.0), Emily Kyker-Snowman, William R. Wieder, Serita D. Frey, A. Stuart Grandy Sep 2020

Stoichiometrically Coupled Carbon And Nitrogen Cycling In The Microbial-Mineral Carbon Stabilization Model Version 1.0 (Mimics-Cn V1.0), Emily Kyker-Snowman, William R. Wieder, Serita D. Frey, A. Stuart Grandy

Faculty Publications

Explicit consideration of microbial physiology in soil biogeochemical models that represent coupled carbon–nitrogen dynamics presents opportunities to deepen understanding of ecosystem responses to environmental change. The MIcrobial-MIneral Carbon Stabilization (MIMICS) model explicitly represents microbial physiology and physicochemical stabilization of soil carbon (C) on regional and global scales. Here we present a new version of MIMICS with coupled C and nitrogen (N) cycling through litter, microbial, and soil organic matter (SOM) pools. The model was parameterized and validated against C and N data from the Long-Term Inter-site Decomposition Experiment Team (LIDET; six litter types, 10 years of observations, and 13 sites …


Drilling Operations For The South Pole Ice Core (Spicecore) Project, Jay A. Johnson, Tanner W. Kuhl, Grant Boeckmann, Chris Gibson, Joshua Jetson, Zachary Meulemans, Kristina Slawny, Joseph M. Souney Sep 2020

Drilling Operations For The South Pole Ice Core (Spicecore) Project, Jay A. Johnson, Tanner W. Kuhl, Grant Boeckmann, Chris Gibson, Joshua Jetson, Zachary Meulemans, Kristina Slawny, Joseph M. Souney

Earth Systems Research Center

Over the course of the 2014/15 and 2015/16 austral summer seasons, the South Pole Ice Core project recovered a 1751 m deep ice core at the South Pole. This core provided a high-resolution record of paleoclimate conditions in East Antarctica during the Holocene and late Pleistocene. The drilling and core processing were completed using the new US Intermediate Depth Drill system, which was designed and built by the US Ice Drilling Program at the University of Wisconsin–Madison. In this paper, we present and discuss the setup, operation, and performance of the drill system.


Microbial Diversity Drives Carbon Use Efficiency In A Model Soil, Luiz A. Domeignoz-Horta, Grace Pold, Xiao-Jun Allen Liu, Serita D. Frey, Jerry M. Melillo, Kristen M. Deangelis Jul 2020

Microbial Diversity Drives Carbon Use Efficiency In A Model Soil, Luiz A. Domeignoz-Horta, Grace Pold, Xiao-Jun Allen Liu, Serita D. Frey, Jerry M. Melillo, Kristen M. Deangelis

Faculty Publications

Empirical evidence for the response of soil carbon cycling to the combined effects of warming, drought and diversity loss is scarce. Microbial carbon use efficiency (CUE) plays a central role in regulating the flow of carbon through soil, yet how biotic and abiotic factors interact to drive it remains unclear. Here, we combine distinct community inocula (a biotic factor) with different temperature and moisture conditions (abiotic factors) to manipulate microbial diversity and community structure within a model soil. While community composition and diversity are the strongest predictors of CUE, abiotic factors modulated the relationship between diversity and CUE, with CUE …


Decomposability Of Soil Organic Matter Over Time: The Soil Incubation Database (Sidb, Version 1.0) And Guidance For Incubation Procedures, Christina Schadel, Jeffrey Beem-Miller, Mina Aziz Rad, Susan E. Crow, Caitlin E. Hicks Pries, Jessica G. Ernakovich, Alison M. Hoyt, Alain Plante, Shane Stoner, Claire C. Treat, Carlos A. Sierra Jul 2020

Decomposability Of Soil Organic Matter Over Time: The Soil Incubation Database (Sidb, Version 1.0) And Guidance For Incubation Procedures, Christina Schadel, Jeffrey Beem-Miller, Mina Aziz Rad, Susan E. Crow, Caitlin E. Hicks Pries, Jessica G. Ernakovich, Alison M. Hoyt, Alain Plante, Shane Stoner, Claire C. Treat, Carlos A. Sierra

Faculty Publications

The magnitude of carbon (C) loss to the atmosphere via microbial decomposition is a function of the amount of C stored in soils, the quality of the organic matter, and physical, chemical, and biological factors that comprise the environment for decomposition. The decomposability of C is commonly assessed by laboratory soil incubation studies that measure greenhouse gases mineralized from soils under controlled conditions. Here, we introduce the Soil Incubation Database (SIDb) version 1.0, a compilation of time series data from incubations, structured into a new, publicly available, open-access database of C flux (carbon dioxide, CO2, or methane, CH4). In addition, …


Heavy Metals In The Arctic: Distribution And Enrichment Of Five Metals In Alaskan Soils, Clarice R. Perryman, Jochen Wirsing, Kathryn A. Bennett, Owen Brennick, Apryl L. Perry, Nicole Williamson, Jessica G. Ernakovich Jun 2020

Heavy Metals In The Arctic: Distribution And Enrichment Of Five Metals In Alaskan Soils, Clarice R. Perryman, Jochen Wirsing, Kathryn A. Bennett, Owen Brennick, Apryl L. Perry, Nicole Williamson, Jessica G. Ernakovich

Faculty Publications

Metal contamination of food and water resources is a known public health issue in Arctic and sub-Arctic communities due to the proximity of many communities to mining and drilling sites. In addition, permafrost thaw may release heavy metals sequestered in previously frozen soils, potentially contaminating food and water resources by increasing the concentration of metals in freshwater, plants, and wildlife. Here we assess the enrichment of selected heavy metals in Alaskan soils by synthesizing publicly available data of soil metal concentrations. We analyzed data of soil concentrations of arsenic, chromium, mercury, nickel, and lead from over 1,000 samples available through …


Indolic Glucosinolate Pathway Provides Resistance To Mycorrhizal Fungal Colonization In A Non-Host Brassicaceae, Mark A. Anthony, J. L. Celenza, A. Armstrong, Serita D. Frey Apr 2020

Indolic Glucosinolate Pathway Provides Resistance To Mycorrhizal Fungal Colonization In A Non-Host Brassicaceae, Mark A. Anthony, J. L. Celenza, A. Armstrong, Serita D. Frey

Faculty Publications

Most terrestrial plants form mycorrhizas, but a number of agricultural plants, including the Brassicaceae, are non-mycorrhizal. Brassicaceae can still be colonized by arbuscular mycorrhizal fungi (AMF), but species like Arabidopsis thaliana experience growth reductions following AMF colonization at similar magnitude to that of fungal pathogen infections and lack key genes necessary for nutrient exchange. Arabidopsis also produces specific secondary compounds via the modification of tryptophan, including indolic glucosinolates (IGs), which have anti-fungal properties and may therefore be involved in reducing AMF colonization. This study therefore addressed whether the ability to produce IGs facilitates resistance to AMF colonization and growth suppression. …


Ramped Thermal Analysis For Isolating Biologically Meaningful Soil Organic Matter Fractions With Distinct Residence Times, Jonathan Sanderman, A. Stuart Grandy Apr 2020

Ramped Thermal Analysis For Isolating Biologically Meaningful Soil Organic Matter Fractions With Distinct Residence Times, Jonathan Sanderman, A. Stuart Grandy

Faculty Publications

In this work, we assess whether or not ramped thermal oxidation coupled with determination of the radiocarbon content of the evolved CO2 can be used to isolate distinct thermal fractions of soil organic matter (SOM) along with direct information on the turnover rate of each thermal fraction. Using a 30-year time series of soil samples from a well-characterized agronomic trial, we found that the incorporation of the bomb spike in atmospheric 14CO2 into thermal fractions of increasing resistance to thermal decomposition could be successfully modeled. With increasing temperature, which is proportional to activation energy, the mean residence time of the …


Correcting Tree-Ring Δ13c Time Series For Tree-Size Effects In Eight Temperate Tree Species, Matthew A. Vadeboncoeur, Katie A. Jennings, Andrew P. Ouimette, Heidi Asbjornsen Apr 2020

Correcting Tree-Ring Δ13c Time Series For Tree-Size Effects In Eight Temperate Tree Species, Matthew A. Vadeboncoeur, Katie A. Jennings, Andrew P. Ouimette, Heidi Asbjornsen

Earth Systems Research Center

Stable carbon isotope ratios (δ13C) in tree rings have been widely used to study changes in intrinsic water-use efficiency (iWUE), sometimes with limited consideration of how C-isotope discrimination is affected by tree height and canopy position. Our goals were to quantify the relationships between tree size or tree microenvironment and wood δ13C for eight functionally diverse temperate tree species in northern New England, and to better understand the physical and physiological mechanisms underlying these differences. We collected short increment cores in closed-canopy stands and analyzed δ13C in the most recent 5 years of growth. …


Long-Term Evidence Shows That Crop-Rotation Diversification Increases Agricultural Resilience To Adverse Growing Conditions In North America, Timothy M. Bowles, Maria Mooshammer, Yvonne Socolar, Francisco Calderon, Michel A. Cavigelli, Steve W. Culman, William Deen, Craig F. Drury, Axel Garcia Y Garcia, Amelie C. M. Gaudin, W. Scott Harkcom, R. Michael Lehman, Shannon L. Osborne, G. Philip Robertson, Jonathan Salerno, Marty R. Schmer, Jeffrey Strock, A. Stuart Grandy Mar 2020

Long-Term Evidence Shows That Crop-Rotation Diversification Increases Agricultural Resilience To Adverse Growing Conditions In North America, Timothy M. Bowles, Maria Mooshammer, Yvonne Socolar, Francisco Calderon, Michel A. Cavigelli, Steve W. Culman, William Deen, Craig F. Drury, Axel Garcia Y Garcia, Amelie C. M. Gaudin, W. Scott Harkcom, R. Michael Lehman, Shannon L. Osborne, G. Philip Robertson, Jonathan Salerno, Marty R. Schmer, Jeffrey Strock, A. Stuart Grandy

Faculty Publications

A grand challenge facing humanity is how to produce food for a growing population in the face of a changing climate and environmental degradation. Although empirical evidence remains sparse, management strategies that increase environmental sustainability, such as increasing agroecosystem diversity through crop rotations, may also increase resilience to weather extremes without sacrificing yields. We used multilevel regression analyses of long-term crop yield datasets across a continental precipitation gradient to assess how temporal crop diversification affects maize yields in intensively managed grain systems. More diverse rotations increased maize yields over time and across all growing conditions (28.1% on average), including in …


Influence Of Forest-To-Silvopasture Conversion And Drought On Components Of Evapotranspiration, Adam P. Coble, Alexandra R. Contosta, Richard G. Smith, Nathan W. Siegert, Matthew A. Vadeboncoeur, Katie A. Jennings, Anthony J. Stewart, Heidi Asbjornsen Mar 2020

Influence Of Forest-To-Silvopasture Conversion And Drought On Components Of Evapotranspiration, Adam P. Coble, Alexandra R. Contosta, Richard G. Smith, Nathan W. Siegert, Matthew A. Vadeboncoeur, Katie A. Jennings, Anthony J. Stewart, Heidi Asbjornsen

Natural Resources & the Environment

The northeastern U.S. is projected to experience more frequent short-term (1-2 month) droughts interspersed among larger precipitation events. Agroforestry practices such as silvopasture may mitigate these impacts of climate change while maintaining economic benefits of both agricultural and forestry practices. This study evaluated the effects of forest-to-silvopasture (i.e., 50% thinning) conversion on the components of evapotranspiration (transpiration, rainfall interception, and soil evaporation) during the growing season of 2016. The study coincided with a late-summer drought throughout the northeastern U.S., which allowed us to also evaluate the effects of forest-to-silvopasture conversion on drought responses of multiple tree species, including Pinus strobus, …


Carbon Use Efficiency And Its Temperature Sensitivity Covary In Soil Bacteria, Grace Pold, Luiz A. Domeignoz-Horta, Eric W. Morrison, Serita D. Frey, Seeta A. Sistla, Kristen M. Deangelis Jan 2020

Carbon Use Efficiency And Its Temperature Sensitivity Covary In Soil Bacteria, Grace Pold, Luiz A. Domeignoz-Horta, Eric W. Morrison, Serita D. Frey, Seeta A. Sistla, Kristen M. Deangelis

Faculty Publications

The strategy that microbial decomposers take with respect to using substrate for growth versus maintenance is one essential biological determinant of the propensity of carbon to remain in soil. To quantify the environmental sensitivity of this key physiological trade-off, we characterized the carbon use efficiency (CUE) of 23 soil bacterial isolates across seven phyla at three temperatures and with up to four substrates. Temperature altered CUE in both an isolate-specific manner and a substrate-specific manner. We searched for genes correlated with the temperature sensitivity of CUE on glucose and deemed those functional genes which were similarly correlated with CUE on …