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Courtney Creamer

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

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Photo of a hillside after a fire

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.
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California Water Science Center, Geology, Minerals, Energy, and Geophysics Science Center, National Innovation Center, Western Geographic Science Center
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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.
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patch of burned conifers in California

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...
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Climate Research and Development Program, Geology, Minerals, Energy, and Geophysics Science Center
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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...
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Louisiana salt marsh

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.
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Land Management Research Program, Wetland and Aquatic Research Center
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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.
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scientists collecting permafrost cores

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...
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Climate Research and Development Program, Geology, Minerals, Energy, and Geophysics Science Center
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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...
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Louisiana salt marsh

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...
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Climate Adaptation Science Centers
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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...
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Scanning electron microscope image of soil biofilm

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...
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Climate Research and Development Program, Earth Systems Biogeochemistry Laboratory
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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...
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Grass 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 (e
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Geology, Minerals, Energy, and Geophysics Science Center

Spatiotemporal 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 associ
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Climate Research and Development Program, Wetland and Aquatic Research Center

Survey 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 phytostabilization
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Geology, Minerals, Energy, and Geophysics Science Center

Batch 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
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Geology, Minerals, Energy, and Geophysics Science Center, Geosciences and Environmental Change Science Center
scientists measuring soil infiltration 2 years after the 2020 LNU Lightning Complex fire
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scientists preparing to collect soil samples 1-year after the Dixie Fire
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scientists sampling soil at burned study site
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patch of burned conifers in California
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scientist in the lab
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sampling a marine terrace soil chronosequence
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Microbial 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., microorgani
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Mineral Resources Program, Geology, Minerals, Energy, and Geophysics Science Center

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

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 Ri
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Ecosystems, Climate Research and Development Program, Land Management Research Program, Alaska Science Center, Geology, Minerals, Energy, and Geophysics Science Center, Wetland and Aquatic Research Center

Mechanisms 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 leverag
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Volcano Hazards, Geology, Minerals, Energy, and Geophysics Science Center, Geosciences and Environmental Change Science Center, Volcano Science Center

Deconstructing 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 wi
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Climate Research and Development Program, Geology, Minerals, Energy, and Geophysics Science Center

Response 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, and
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Ecosystems, Climate Research and Development Program, Land Change Science Program, Southwest Biological Science Center

A 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 or
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Climate Research and Development Program, Land Change Science Program, Geology, Minerals, Energy, and Geophysics Science Center

Linking 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 rate
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Geology, Minerals, Energy, and Geophysics Science Center

From 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 suggest
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Ecosystems, Climate Research and Development Program, Land Change Science Program, Southwest Biological Science Center

Soil 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 communities
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Geology, Minerals, Energy, and Geophysics Science Center

Mineralogy 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 mec
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Geology, Minerals, Energy, and Geophysics Science Center

Biological 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, w
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Climate Research and Development Program, Land Change Science Program, Geology, Minerals, Energy, and Geophysics Science Center, Geosciences and Environmental Change Science Center

Science and Products