Courtney's research is broadly focused on how the chemistry and accessibility of soil organic matter influences its turnover and stabilization, and subsequently, how this impacts the functioning of natural and managed ecosystems.
Many of the global challenges we face (climate change, biodiversity loss, food security) are dependent upon soil processes, and her work examines current controls on soil carbon and nitrogen stability with the aim of predicting and managing the response of soils to global change scenarios. Her particular expertise lies in linking the quantity, accessibility, and chemical composition of soil carbon and nitrogen to microbial activity and community composition, using a variety of methods. Previous projects have focused plant-soil-microbe feedbacks in response along gradients of grassland and rangeland degradation (Australia and Texas), nutrient enrichment, and edaphic properties.
Professional Experience
2015 - present Research Microbiologist (post-doc), USGS, Menlo Park CA
2012 - 2015 Office of the Chief Executive Postdoctoral Fellow, CSIRO, Adelaide SA, Australia
2008 - 2012 Graduate Research and Teaching Assistant, Purdue University, West Lafayette IN
2006 - 2007 Undergraduate Research Assistant, Miami University, Oxford OH
2005 - Laboratory Intern, Case Western Reserve, Cleveland, OH
Education and Certifications
Ph.D., Purdue University, Earth, Atmospheric, and Planetary Sciences, 2012
B.A., Miami University (Ohio), Microbiology, 2007
Science and Products
Characterizing high-resolution soil burn severity, erosion risk, and recovery using Uncrewed Aerial Systems (UAS)
Response of plant, microbial, and soil functions to drought and fire in California
Understanding Impacts of Sea-Level Rise and Land Management on Critical Coastal Marsh Habitat
Arctic Biogeochemical Response to Permafrost Thaw (ABRUPT)
Understanding Impacts of Sea-Level Rise and Land Management on Critical Coastal Marsh Habitat
Biogeochemistry of the Critical Zone: Origin and Fate of Organic Matter
Phytostabilization in Polymetallic Tailings using Compost and Endophyte Additions
Abiotic sorption of glucose, glutamic acid, hydroxybenzoic acid, and oxalic acid onto amorphous aluminum hydroxide, feldspar, ferrihydrite, and kaolinite
U.S. Geological Survey Soil Sample Archive
Grass Growth in Mining Wastes with Compost and Endophyte Additions
Spatiotemporal dynamics of soil carbon following coastal wetland loss at a Louisiana coastal salt marsh in the Mississippi River Deltaic Plain in 2019
Survey of metals in soils and associated endemic plants across the historic Harshaw Mining District, Southern Arizona
Batch sorption data, respired CO2, extractable DOC, and Raman spectra collected from an incubation with microbial necromass on feldspar or amorphous aluminum hydroxide
Compost, plants and endophytes versus metal contamination: Choice of a restoration strategy steers the microbiome in polymetallic mine waste
Microbial endophytes and compost improve plant growth in two contrasting types of hard rock mining waste
A model of the spatiotemporal dynamics of soil carbon following coastal wetland loss applied to a Louisiana salt marsh in the Mississippi River Deltaic Plain
Mechanisms for retention of low molecular weight organic carbon varies with soil depth at a coastal prairie ecosystem
Deconstructing the microbial necromass continuum to inform soil carbon sequestration
Response to ‘Stochastic and deterministic interpretation of pool models’
A combined microbial and ecosystem metric of carbon retention efficiency explains land cover-dependent soil microbial biodiversity–ecosystem function relationships
Linking decomposition rates of soil organic amendments to their chemical composition
From pools to flow: The PROMISE framework for new insights on soil carbon cycling in a changing world
Soil microbial communities and global change
Mineralogy dictates the initial mechanism of microbial necromass association
Biological and mineralogical controls over cycling of low molecular weight organic compounds along a soil chronosequence
Science and Products
- Science
Characterizing high-resolution soil burn severity, erosion risk, and recovery using Uncrewed Aerial Systems (UAS)
The western United States is experiencing severe wildfires whose observed impacts, including post-wildfire floods and debris flows, appear to be increasing over time.Response of plant, microbial, and soil functions to drought and fire in California
California is experiencing changes in precipitation and wildfire regimes. Longer, hotter fire seasons along with extremes in precipitation are expected to continue. Not only do these disturbances affect the productivity and resilience of ecosystems, they also directly impact human health and wellbeing. Soils hold an immense amount of our terrestrial carbon pool, and the microorganisms and minerals...Understanding Impacts of Sea-Level Rise and Land Management on Critical Coastal Marsh Habitat
To ensure successful restoration of coastal wetlands, WARC researchers will measure carbon cycling processes that indicate ecosystem health and sustainability.Arctic Biogeochemical Response to Permafrost Thaw (ABRUPT)
Warming and thawing of permafrost soils in the Arctic is expected to become widespread over the coming decades. Permafrost thaw changes ecosystem structure and function, affects resource availability for wildlife and society, and decreases ground stability which affects human infrastructure. Since permafrost soils contain about half of the global soil carbon (C) pool, the magnitude of C losses...Understanding Impacts of Sea-Level Rise and Land Management on Critical Coastal Marsh Habitat
The Science Issue and Relevance: Coastal wetlands are some of the most productive and valuable habitats in the world. Louisiana contains 40% of the United States’ coastal wetlands, which provide critical habitat for waterfowl and fisheries, as well as many other benefits, such as storm surge protection for coastal communities. In terms of ecosystem services, biological resource production, and inf...Biogeochemistry of the Critical Zone: Origin and Fate of Organic Matter
Changing temperature, precipitation, and land use intensification has resulted in global soil degradation. The accompanying loss of soil organic matter (SOM) decreases important soil health services. Soil organic matter is a major global pool of carbon; if SOM can be increased, soils can mitigate elevated atmospheric CO2. However, there are major knowledge gaps in SOM persistence. This project... - Data
Phytostabilization in Polymetallic Tailings using Compost and Endophyte Additions
Mining wastes can pose environmental hazards. These hazards can be mitigated by promoting the growth of native plants that can stabilize the mine wastes and potentially toxic elements in situ (i.e., phytostabilization). We grew a widespread perennial grass species (Bouteloua curtipendula) in dolomite amended polymetallic tailings from a historic mine in southeastern Arizona (USA). We applied a comAbiotic sorption of glucose, glutamic acid, hydroxybenzoic acid, and oxalic acid onto amorphous aluminum hydroxide, feldspar, ferrihydrite, and kaolinite
Abiotic sorption experiments were conducted with four carbon substrates (glucose, glutamic acid, oxalic acid, para-hydroxybenzoic acid) on four clay minerals (kaolinite, feldspar, ferrihydrite, amorphous aluminum hydroxide) after sterilization by gamma irradiation. The adsorption isotherms were carried across a range of substrate carbon concentrations (0, 20, 100, and 500 mg carbon per L) and pH cU.S. Geological Survey Soil Sample Archive
The U.S. Geological Survey (USGS) Soil Sample Archive is a database of information describing soil and sediment samples collected in support of USGS science. Samples in the archive have been registered with International Generic Sample Numbers, relabeled with bar-coded sample labels, and repacked in containers for long-term preservation. Details of sample collection location, collection date, assoGrass Growth in Mining Wastes with Compost and Endophyte Additions
Phytostabilization reduces the mobility of inorganic contaminants by establishing or enhancing plant growth. For small, remote, or abandoned mines, phytostabilization may reduce potential environmental hazards—provided plants can establish and grow. We grew a widespread perennial grass, Bouteloua curtipendula, in mining wastes with and without soil (compost, lime) and microbial amendments (endophySpatiotemporal dynamics of soil carbon following coastal wetland loss at a Louisiana coastal salt marsh in the Mississippi River Deltaic Plain in 2019
This dataset provides the water content, bulk density, carbon concentrations, nitrogen concentrations, and carbon content of all fourteen cores sampled in coastal Louisiana (CRMS 0224) in October of 2019. Each sample is identified by a unique identifier that corresponds to each site by depth increment combination. The pond age range associated with each site is provided. The depth increment associSurvey of metals in soils and associated endemic plants across the historic Harshaw Mining District, Southern Arizona
The legacy of mining exploration and operations can remain for decades to centuries if not treated, posing risks to human and animal health due to fugitive dispersal of metal(loid) laden dust and water. The use of endemic plants is key to the success of phytostabilization because endemics are adapted to the conditions prevailing in local mine sites. To this end, we evaluated the phytostabilizationBatch sorption data, respired CO2, extractable DOC, and Raman spectra collected from an incubation with microbial necromass on feldspar or amorphous aluminum hydroxide
These datasets are from an incubation experiment with a combination of two minerals (feldspar or amorphous aluminum hydroxide), one living species of bacteria (Escherichia coli), and one added form of C (Arthrobacter crystallopoietes necromass). We characterized the sorptive properties of the minerals with batch sorption experiments using four low molecular weight C substrates (glucose, oxalic aci - Multimedia
- Publications
Compost, plants and endophytes versus metal contamination: Choice of a restoration strategy steers the microbiome in polymetallic mine waste
Finding solutions for the remediation and restoration of abandoned mining areas is of great environmental importance as they pose a risk to ecosystem health. In this study, our aim was to determine how remediation strategies with (i) compost amendment, (ii) planting a metal-tolerant grass Bouteloua curtipendula, and (iii) its inoculation with beneficial endophytes influenced the microbiome of metaAuthorsMartina Kracmarova, Jakub Papik, Ondrej Uhlik, John Freeman, Andrea L. Foster, Mary-Catherine Leewis, Courtney CreamerMicrobial endophytes and compost improve plant growth in two contrasting types of hard rock mining waste
The re-vegetation of mining wastes with native plants is a comparatively low-cost solution for mine reclamation. However, re-vegetation fails when extreme pH values, low organic matter, or high concentrations of phytotoxic elements inhibit plant establishment and growth. Our aim was to determine whether the combined addition of municipal waste compost and diazotrophic endophytes (i.e., microorganiAuthorsCourtney Creamer, Mary-Catherine Leewis, Francesca C. Governali, John Freeman, Floyd Gray, Emily G. Wright, Andrea L. FosterA model of the spatiotemporal dynamics of soil carbon following coastal wetland loss applied to a Louisiana salt marsh in the Mississippi River Deltaic Plain
The potential for carbon sequestration in coastal wetlands is high due to protection of carbon (C) in flooded soils. However, excessive flooding can result in the conversion of the vegetated wetland to open water. This transition results in the loss of wetland habitat in addition to the potential loss of soil carbon. Thus, in areas experiencing rapid wetland submergence, such as the Mississippi RiAuthorsDonald R. Schoolmaster, Camille Stagg, Courtney Creamer, Claudia Laurenzano, Eric Ward, Mark Waldrop, Melissa M. Baustian, Tiong Aw, Sergio Merino, Rachel Katherine Villani, Laura ScottMechanisms for retention of low molecular weight organic carbon varies with soil depth at a coastal prairie ecosystem
Though primary sources of carbon (C) to soil are plant inputs (e.g., rhizodeposits), the role of microorganisms as mediators of soil organic carbon (SOC) retention is increasingly recognized. Yet, insufficient knowledge of sub-soil processes complicates attempts to describe microbial-driven C cycling at depth as most studies of microbial-mineral-C interactions focus on surface horizons. We leveragAuthorsJack McFarland, Corey Lawrence, Courtney Creamer, Marjorie S. Schulz, Christopher H. Conaway, Sara Peek, Mark Waldrop, Sabrina N. Sevilgen, Monica HawDeconstructing the microbial necromass continuum to inform soil carbon sequestration
Microbial necromass is a large, dynamic and persistent component of soil organic carbon, the dominant terrestrial carbon pool. Quantification of necromass carbon stocks and its susceptibility to global change is becoming standard practice in soil carbon research. However, the typical proxies used for necromass carbon do not reveal the dynamic nature of necromass carbon flows and transformations wiAuthorsKate M Buckeridge, Courtney Creamer, Jeanette WhitakerResponse to ‘Stochastic and deterministic interpretation of pool models’
We concur with Azizi‐Rad et al. (2021) that it is vital to critically evaluate and compare different soil carbon models, and we welcome the opportunity to further describe the unique contribution of the PROMISE model (Waring et al. 2020) to this literature. The PROMISE framework does share many features with established biogeochemical models, as our original manuscript highlighted in Table 1, andAuthorsBonnie G. Waring, Benjamin N. Sulman, Sasha C. Reed, A. Peyton Smith, Colin Averill, Courtney Creamer, Daniela F. Cusack, Steven J. Hall, Julie D. Jastrow, Andrea Jilling, Kenneth M. Kemner, Markus Kleber, Xiao-Jun Allen Liu, Jennifer Pett-Ridge, Marjorie S. SchulzA combined microbial and ecosystem metric of carbon retention efficiency explains land cover-dependent soil microbial biodiversity–ecosystem function relationships
While soil organic carbon (C) is the foundation of productive and healthy ecosystems, the impact of the ecology of microorganisms on C-cycling remains unknown. We manipulated the diversity, applied here as species richness, of the microbial community present in similar soils on two contrasting land-covers—an adjacent pasture and forest—and observed the transformations of plant detritus and soil orAuthorsJessica G. Ernakovich, Jeffrey R Baldock, Courtney Creamer, Jonathan Sanderman, Karsten Kalbitz, Mark FarrellLinking decomposition rates of soil organic amendments to their chemical composition
The stock of organic carbon contained within a soil represents the balance between inputs and losses. Inputs are defined by the ability of vegetation to capture and retain carbon dioxide, effects that management practices have on the proportion of captured carbon that is added to soil and the application organic amendments. The proportion of organic amendment carbon retained is defined by its rateAuthorsJeffrey R Baldock, Courtney Creamer, Steve Szarvas, Janine McGowan, T. Carter, Mark FarrellFrom pools to flow: The PROMISE framework for new insights on soil carbon cycling in a changing world
Soils represent the largest terrestrial reservoir of organic carbon, and the balance between soil organic carbon (SOC) formation and loss will drive powerful carbon‐climate feedbacks over the coming century. To date, efforts to predict SOC dynamics have rested on pool‐based models, which assume classes of SOC with internally homogenous physicochemical properties. However, emerging evidence suggestAuthorsBonnie G. Waring, Benjamin N. Sulman, Sasha C. Reed, A. Peyton Smith, Colin Averill, Courtney Creamer, Daniela F. Cusack, Steven J. Hall, Julie Jastrow, Kenneth M. Kemner, Markus Kleber, Xiao-Jun Allen Liu, Jennifer Pett-Ridge, Marjorie S. SchulzSoil microbial communities and global change
Soils and soil microbial communities mediate the biogeochemical processes that underly ecosystem-level changes. This chapter examines why soils and soil microbial communities are important for understanding impacts and feedbacks to global change. It discusses the technological approaches and challenges that are at the frontiers of this research area. Global change impacts on microbial communitiesAuthorsMark P. Waldrop, Courtney CreamerMineralogy dictates the initial mechanism of microbial necromass association
Soil organic matter (SOM) improves soil fertility and mitigates disturbance related to climate and land use change. Microbial necromass (the accumulated cellular residues of microorganisms) comprises the majority of soil C, yet the formation and persistence of necromass in relation to mineralogy is poorly understood. We tested whether soil minerals had different microbial necromass association mecAuthorsCourtney Creamer, Andrea L. Foster, Corey Lawrence, Jack McFarland, Marjorie S. Schulz, Mark WaldropBiological and mineralogical controls over cycling of low molecular weight organic compounds along a soil chronosequence
Low molecular weight organic compounds (LMWOC) represent a small but critical component of soil organic matter (SOM) for microbial growth and metabolism. The fate of these compounds is largely under microbial control, yet outside the cell, intrinsic soil properties can also significantly influence their turnover and retention. Using a chronosequence representing 1200 ka of pedogenic development, wAuthorsJack McFarland, Mark P. Waldrop, Daniel Strawn, Courtney Creamer, Corey R. Lawrence, Monica Haw