A5025602961- Soil Carbon and Nitrogen Dynamics
- Soil and Water Nutrient Dynamics
- Peatlands and Wetlands Ecology
- Soil and Unsaturated Flow
- Clay minerals and soil interactions
- Soil Geostatistics and Mapping
- Isotope Analysis in Ecology
- Geochemistry and Geologic Mapping
- Geology and Paleoclimatology Research
- Atmospheric and Environmental Gas Dynamics
- Microbial Community Ecology and Physiology
- Hydrocarbon exploration and reservoir analysis
- Heavy metals in environment
- Iron oxide chemistry and applications
- Coal and Its By-products
- Plant Water Relations and Carbon Dynamics
- Ecology and Vegetation Dynamics Studies
- Mineral Processing and Grinding
- Radioactive element chemistry and processing
- Groundwater and Isotope Geochemistry
- Invertebrate Taxonomy and Ecology
- Scientific Research and Discoveries
- Hydrology and Watershed Management Studies
- Thermochemical Biomass Conversion Processes
- Plant Ecology and Soil Science
University of Pennsylvania
2016-2025
University City Science Center
2025
California University of Pennsylvania
2017-2022
Soil Science Research Unit
2002-2016
Colorado State University
2006-2008
Villanova University
2006
Institut National de la Recherche Agronomique
2004-2005
University of Alberta
1998-2002
Abstract The relationship between organic matter (OM) lability and temperature sensitivity is disputed, with recent observations suggesting that responses of relatively more resistant OM to increased could be greater than, equivalent to, or less than labile OM. This lack clear understanding limits the ability forecast carbon (C) cycle changes. Here, we derive a novel approach (denoted Q 10− q ) accounts for changes in quality during decomposition use it analyze data from three independent...
Abstract Soil carbon turnover models generally divide soil into pools with varying intrinsic decomposition rates. Although these rates are modified by factors such as temperature, texture, and moisture, they rationalized assuming chemical structure is a primary controller of decomposition. In the current work, we use near edge X‐ray absorption fine (NEXAFS) spectroscopy in combination differential scanning calorimetry (DSC) alkaline cupric oxide (CuO) oxidation to explore this assumption....
Summary Primary organo‐mineral complexes are defined as organic matter (OM) bound to primary mineral particles, isolated after complete dispersion of soil. Organic present in < 2 μm particle‐size fractions soils has slow turnover times and it is assumed be stabilized mainly by interaction with minerals. We aimed quantify how much the was free versus minerals describe nature association. Furthermore, we hypothesized that this more resistant biodegradation than particles. tested using a...
Previous research on the protection of soil organic C from decomposition suggests that texture affects stocks. However, different pools matter (SOM) might be differently related to texture. Our objective was examine how differentially alters distribution within physically and chemically defined unprotected protected SOM. We collected samples two gradients where other variables influencing content were held constant. One gradient (16–60% clay) located near Stewart Valley, Saskatchewan, Canada...
The soil C saturation concept suggests a limit to whole organic carbon (SOC) accumulation determined by inherent physicochemical characteristics of four pools: unprotected, physically protected, chemically and biochemically protected. Previous attempts quantify sequestration capacity have focused primarily on silt clay protection largely ignored the effects structural biochemical protection. We assessed two contrasting models SOC accumulation, one with no (i.e., linear first‐order model) an...
Iron (Fe)-bearing mineral phases contribute disproportionately to adsorption of soil organic matter (SOM) due their elevated chemical reactivity and specific surface area (SSA). However, the spectrum Fe solid-phase speciation present in oxidation–reduction-active soils challenges analysis SOM–mineral interactions may induce differential molecular fractionation dissolved (DOM). This work used paired selective dissolution experiments batch sorption postextraction residues (1) quantify...
Soil profiles are rarely homogeneous. Resource availability and microbial abundances typically decrease with soil depth, but microbes found in deeper horizons still important components of terrestrial ecosystems. By studying 20 across the United States, we documented consistent changes bacterial archaeal communities depth. Deeper soils harbored distinct from those more commonly studied surface horizons. Most notably, that candidate phylum Dormibacteraeota (formerly AD3) was often dominant...
Understanding the controls on amount and persistence of soil organic carbon (C) is essential for predicting its sensitivity to global change. The response may depend whether C unprotected, isolated within aggregates, or protected from decomposition by mineral associations. Here, we present a synthesis relative influence environmental factors partitioning among pools, abundance in each pool (mg g-1 soil), (as approximated radiocarbon abundance) relatively unprotected particulate mineral-bound...
Soil C decomposition is sensitive to changes in temperature, and even small increases temperature may prompt large releases of from soils. But much what we know about soil responses global change based on short‐term incubation data model output that implicitly assumes pools are composed organic matter fractions with uniform sensitivities. In contrast, kinetic theory chemical reactions suggests older, more‐resistant be more sensitive. Recent research the subject inconclusive, indicating...
The literature was reviewed and analyzed to determine the feasibility of using a combination acid hydrolysis CO 2 –C release during long‐term incubation soil organic carbon (SOC) pool sizes mean residence times (MRTs). Analysis 1100 data points showed SOC remaining after with 6 M HCl ranged from 30 80% total depending on type, depth, texture, management. Nonhydrolyzable (NHC) in conventional till soils represented 48% SOC; no‐till averaged 56%, forest 55%, grassland 56%. Carbon dates an...