A5025100854- Soil Carbon and Nitrogen Dynamics
- Geology and Paleoclimatology Research
- Cryospheric studies and observations
- Climate change and permafrost
- Iron oxide chemistry and applications
- Soil and Water Nutrient Dynamics
- Clay minerals and soil interactions
- Peatlands and Wetlands Ecology
- Heavy metals in environment
- Biocrusts and Microbial Ecology
- Soil erosion and sediment transport
- Plant Growth Enhancement Techniques
- Microbial Community Ecology and Physiology
- Methane Hydrates and Related Phenomena
- Geochemistry and Geologic Mapping
- Mycorrhizal Fungi and Plant Interactions
- Landslides and related hazards
- Atmospheric and Environmental Gas Dynamics
- Marine and coastal plant biology
- Phosphorus and nutrient management
- Radioactive element chemistry and processing
- Aluminum toxicity and tolerance in plants and animals
- Soil, Finite Element Methods
- Gas Sensing Nanomaterials and Sensors
- Fire effects on ecosystems
Virginia Tech
2020-2024
Cornell University
2015-2022
University of Rhode Island
2015
Ottawa University
2013
Roger Williams University
2013
Abstract The capacity of soil as a carbon (C) sink is mediated by interactions between organic matter and mineral phases. However, previously proposed layered accumulation within aggregate organo–mineral microstructures has not yet been confirmed direct visualization at the necessary nanometer-scale spatial resolution. Here, we identify disordered micrometer-size phases rather than reported ordered gradients in C functional groups. Using cryo-electron microscopy with electron energy loss...
Mineral stabilization of soil organic matter is an important regulator the global carbon (C) cycle. However, vulnerability mineral-stabilized (OM) to climate change currently unknown. We examined profiles from 34 sites across conterminous USA investigate how abundance and persistence mineral-associated C varied with at continental scale. Using a novel combination radiocarbon molecular composition measurements, we show that relationship between (MAOM) appears be driven by moisture...
Climate change in Arctic landscapes may increase freeze–thaw frequency within the active layer as well newly thawed permafrost. Freeze-thaw is a highly disruptive process that can deform soil pores and alter architecture of pore network with varied impacts to water transport retention, redox conditions, microbial activity. Our objective was investigate how cycles impacted permafrost aggregates improve understanding what type transformations be expected from warming landscapes. We measured...
Organic compounds exuded by plant roots can form organo-mineral associations through physico-chemical interactions with soil minerals but disrupt existing increasing their microbial decomposition and dissolution. The controls on these opposing processes are poorly understood, as the chemical spatial characteristics of which may explain gain or loss organic matter at root-soil interface termed rhizosphere. By pulse-labeling 13C-carbon dioxide, we found that maize root exudates increased in...
Abstract Variation in soil organic C (%OC) concentration has been associated with the of reactive Fe- and Al-oxyhydroxide phases exchangeable Ca, relative importance these two stabilizing components shifting as pH moves from acid to alkaline. However, it is currently unknown if this pattern similar or different regard measures persistence. We sampled soils 3 horizons (uppermost A, uppermost B, lowest B horizons) across a gradient 11 grass-dominated 13 deciduous/mixed forest-dominated NEON...
Abstract The rarity of rapid campaigns to characterize soils across scales limits opportunities investigate variation in soil carbon stocks (SOC) storage simultaneously at large and small scales, with without site-level replication. We used data from two complementary 40 sites the United States National Ecological Observatory Network (NEON), which one campaign sampled profiles closely co-located intensive plots physically composited similar horizons, other dozens pedons landscape each site....
Abstract Freeze‐thaw is a disturbance process in cold regions where permafrost soils are becoming vulnerable to temperature fluctuations above 0°C. alters soil physical and biogeochemical properties with implications for carbon persistence emissions Arctic landscapes. We examined whether different freeze‐thaw histories two systems led contrasting responses under laboratory‐controlled incubation. investigated controls on composition through Fourier‐transform ion cyclotron resonance mass...
The spatial distribution of organic substrates and microscale soil heterogeneity significantly influence matter (OM) persistence as constraints on OM accessibility to microorganisms. However, it is unclear how changes in driven by factors such depth affect the relative importance substrate persistence. This work evaluated decomposition 13C 15N labeled water-extractable inputs over 50 days either hotspot (i.e., pelleted 1–2 mm-size pieces) or distributed added < 0.07 μm suspended water) forms...
Abstract As a cover crop, buckwheat ( Fagopyrum esculentum ) may increase soil‐P availability. Buckwheat was grown in low‐P and P‐fertilized field plots, organic anions were measured rhizosphere soil. Soil‐P availability not affected by buckwheat, but the concentration of tartrate 2– significantly higher p < 0.005) vs. plots. This suggests that organic‐anion root exudation have role buckwheat‐rhizosphere P dynamics.
Subsoils store at least 50% of soil organic carbon (SOC) globally, but climate change may accelerate subsoil SOC (SOCsub) decomposition and amplify SOC-climate feedbacks. The sensitivity SOCsub varies across systems, we lack the mechanistic links needed to predict system-specific vulnerability as a function measurable properties larger scales. Here, show that chemical exert significant control over under elevated temperature moisture in subsoils collected terrestrial National Ecological...
The practice of applying seaweed to agricultural fields may provide plant nutrients and improve soil quality in coastal agroecosystems, but little is known about its effects on properties or crop production. We conducted a preliminary evaluation changes biological chemical sweet corn (Zea mays L.) production using as partial source nitrogen (N) (40–55%) for one growing season, preformulated organic fertilizer treatment comparison. Soil electrical conductivity, potassium (K+), sulfate...
Abstract Freeze‐thaw cycles (FTC) alter soil function through changes to physical organization of the matrix and biogeochemical processes. Understanding how dynamic climate properties influence FTC may enable better prediction ecosystem response changing patterns. In this study, we quantified occurrence frequency across 40 National Ecological Observatory Network (NEON) sites. We used site mean annual precipitation (MAP) temperature (MAT) define warm wet, dry, cold dry groupings. Site...
Manganese (Mn) may play an outsized role in soil biogeochemical cycles relative to its abundance. The of Mn-facilitated oxidation biomacromolecules during litter decomposition is well-established, but the balance between Mn-promoted organic carbon (SOC) and long-term SOC protection mineral soils unknown, especially subsoils. In this study, we used collected across US National Ecological Observatory Network (NEON) assess distribution Mn relationships abundance concentration, potential...
Abstract Soil organic matter (SOM) is the largest terrestrial pool of carbon, and potential carbon-climate feedbacks involving SOM decomposition could exacerbate anthropogenic climate change. However, our understanding controls on mineralization still incomplete, as such, ability to predict limited. To improve decomposition, A upper B horizon soil samples from 26 National Ecological Observatory Network (NEON) sites spanning conterminous U.S. were incubated for 52 weeks under conditions...
<title>Abstract</title> Plant root exudates can form organo-mineral associations (OMAs) through physico-chemical interactions with soil mineral surfaces but disrupt existing OMAs by increasing microbial decomposition and dissolution of OMAs. The controls on these seemingly opposing processes are not well understood, nor OMA chemical spatial characteristics that may explain net organic matter (SOM) gain or loss at the root-soil interface termed rhizosphere. By labeling maize plants...
&lt;p&gt;Organo mineral associations intermediated by Fe and Al are considered one of the most important mechanisms for soil organic carbon (SOC) stabilization. However, since normally mentioned together as stabilizing agents, we still lack knowledge about their relative role. In addition, this stabilization mechanism can be profoundly affected climate differences, but magnitude influence whether a direct effect or an indirect consequence due to changes in mineralogy is not yet fully...